STUDIES ON THE INTESTINAL BACTERIAL FLORA OF THE CHICK I. II. Studies on the effect of certain antibiotics upon bacterial populations* Studies on the effect of penicillin on the production of certain B-vitamins. Robert J f Driesens A N ABSTRACT Submitted to the School of Graduate Studies of Michigan State College of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Bacteriology and Public Health 1952 Approved A3 3'151ACT S3U3IJS OIT 013 IIIBlSTIdrI BACTillAI FLORA 33 ILL; CHICII. I. Studies on the effect of certain antibiotics u p o n bacterial populations. II. Studies on the effect of penicillin on the p r o d u c t i o n of certain B-vitamins. A thesis for the degree of Doctor o f Philosplrjby Robert J. Driesens Michigan State College Bast Lansing, Michigan 1952 Bari" vorhers who studied the intestinal flora o f chicirens failed so relate the nature of the bacteria to tne health. o r nutritional condition of eroerirental fowl. More r e c e n t studies tend to minimize the concept of tonic metabolic i n f l u e n c e s urpon the host in favor of tne idea that the status of v i t a m i n a s s i m i lation is affected. -o sterilization of animal intestines b p b & c t e r i o s t a t s antibiotics nas been noted. or Growth stimulation by c e r t a i n a n t i biotics has been reported when they were ea.pl oyed in c o n c e n t r a t ions of a low order or when bacteriostatic activity w a s by treatment with heat or chemicals. eliminated The characteristics os' the bacterial flora are apparently affected sy the nature of the dietary components. Growth stimu lation by procaine penicillin G and streptomycin does not appear to be invariably related to the total numbers of bacteria nor to the quantity of any particular type. Suppression of enterococci by penicillin is of questionable significance, because of their comparatively low concentration in the intestinal areas involved. Bacterial numbers tend to be highest within the intestines of chicks exhibiting maximal or minimal growth rates. JDnterococci were most numerous throughout the inoestinal tract of chicks which gave evidence of inferior growth. Estimation of certain B-vitanins in intestines reveals marked increase of cecal folic acid when penicillin is incorporated into the diet. Dialysis of chick feed supplemented with pancreatin and cecal feces reveals no alteration in dialysis rates at 4 to 6 hours. Production of folic acid was favored in vitro by penicillin. STUDIES ON THE INTESTINAL BACTERIAL FLORA OF THE CHICK I, II. Studies on the effect of certain antibiotics upon bacterial populations. Studies on the effect of penicillin on the production of certain B-vitamins. By Robert J . Driesens A THESIS Submitted to the School of Graduate Studies of Michigan State College of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Bacteriology and Public Health 1952 Robert James Driesens candidate for the degree of Doctor of Philosophy Pinal examination, May 21, 1952, 9:00 A. M . , Ward Giltner Hall, Room 32'6. Dissertation: Studies on the Intestinal Bacterial Flora of the Chick* I. Studies on the effect of certain anti biotics upon bacterial populations. II. Studies on the effect of penicillin on production of certain B-vitamins. Outline of Studies: Major subject: Minor subject: Bacteriology Biochemistry Biographical Items Born, January 12, 1918, Redford, Michigan Undergraduate Studies, Calvin College, 1935-39 Graduate Studies, Michigan State College, 1946-52 Experience: Graduate research assistant, Michigan State College, 1949-52 Member U. S. Army, 1942-46 Member of the Society of American Bacteriologists, the Society Of Sigma Xi ACKNOWLEDGEMENTS The author wishes to express his appreciation to Dr. W. L. Mallmann under whose supervision the investigation was under taken and to Dr. A. C. Groschke for advice and guidance given* He is also indebted to Dr. B. J. Evans and Mrs. Helen A. Butts for their suggestions and assistance, especially in respect to microbiological vitamin assays. To Miss Harriet Hall, Mr. Nazar El Shawi and Mr. Wendell Claxton for their technical assistance and cooperation the writer wishes to express his thanks. The project was supported in part by funds supplied by Merck and Company, Rahway, New Jersey, administered through the Poultry Husbandry Department, Michigan State College. TABLE OF CONTENTS STUDIES ON THE INTESTINAL BACTERIAL FLORA OF TEE CHICK STUDIES ON THE EFFECT OF CERTAIN ANTIBIOTICS UI?ON BACTERIAL’ POPULATIONS. Page 1 INTRODUCTION HISTORICAL REVIEW 2 THE FUNCTIONS OF DIETARY ANTIBIOTICS 12 EXPERIMENTAL 16 Methods of study 16 Review of media 16 Techniques 20 ResiULts 24- Discussion 30 THE EFFECT OF DIETARY PENICILLIN ON PRODUCTION OF CERTAIN B VITAMINS. INTRODUCTION 35 EXPERIMENTAL 35 RESULTS 37 CONCLUSIONS 40 ’EREHCES 42 L .D3 49 ’ENDIX i INTRODUCTION The interest of specialists and laymen alike has been captured by the spectacular effects of antibiotic feed supplements upon certain do mestic animals. Periodically, the daily newspapers, Sunday supplements and trade papers carry accounts of economies gained by their use. Fortune magazine (l) estimates that the use of antibiotics in feeds may ultimately become worth a half-billion dollars to the United States farm economy. This is in terms of the values of the antibiotics as sales items and also in terms of reduction of animal mortality rates and savings in the use of expensive protein food supplements. In the summer o f 1950 the investigation to be described was begun as a part of a broad program instituted by the Poultry Husbandry Department of Michigan State College. It was a cooperative effort involving studies by physiologists, chemists and nutritionists. The purpose o f the bacterio logical studies was to estimate, if possible, the relationship of the bacterial populations to the growth rates of chicks as reflecting the use of antibiotics in feeds. HISTORICAL REVIEW Early Studies on Chicken Flora The Information concerning the bacterial flora of the chicken is rather limited. Apparently, few workers explored the complete flora of poultry until recently. Interest in the intestinal flora of man, particularly the patho genic types, led to speculation as to the relationship of the normal flora to health and longevity. Pasteur (£7), in 1855, expressed the opinion that higher forms of life depended on the lower forms including intestinal bacteria. In his historic studies on beri-beri, Eijkman (20) was among the first to discover what was later to be called "refection". Hens fed raw potato starch failed to develop polyneuritis contrary to expectation. Eijkman recognized the possibility of formation of chemical products from the diet as a result of bacterial action. G-eim-free Studies In an attempt to understand the role of the microflora of the gut, Schottelius (78,79,80,81) raised normal and germ-free chickens on diets which today would be considered totally inadequate. The slow growth and abnormalities of his chicks were such that he concluded that normal chickens could not be raised germ-free. He concluded (81) that the func tion of the normal, nonpathogenic flora was to aid in preparing ingesta for absorption, to stimulate the intestinal wall and promote peristalsis, to oppose the establishment of foreign pathogens and to aid the defenses of the host in combating pathogens and bacterial toxins. In 1913 Schottelius (81) reviewed work on the general subject, especially that of his former associate, Cohendy. He took issue with a longevity theory of the Metchnikoff group, namely, that the total bacteria in the intestinal tract (a function of the size of the gut) as related to the size of the animal was in inverse proportion to the life span. Schot telius pointed to the age and size of the elephant and remarked that the concentration or amount per unit volume was more significant. Cohendy in 1918 reported his results on g e m - f r e e work. too, were protein and vitamin deficient. chicks beyond five weeks. His diets He was unable to rear sterile Neither Cohendy nor Schottelius were concerned with the systematic classification of the bacteria in their studies. Quan titative assays were not made. Balzam ( 5 ) , cited by Reyniers (74), reared five chickens germ-free up to two months. fed the same diets. Their development was similar to that of control birds Deficiency-inducing diets fed to control and germ-free birds revealed no essential differences in the degrees of avitaminosis or body development. Balzam concluded that the intestinal flora of chickens did not exert any appreciable effect on the assimilation of food. of flora had no effect on the requirements for vitamins. The lack This work was re ported in 1937. Reyniers, loc. cit., was able to grow chickens germ-free for four months on commercial feeds. Results were inconclusive as to whether the growth rate was materially affected by absence or presence of intestinal - microbes. 4- In some cases (experiment 4) the germ-free birds grew better. A principal difficulty was the alteration of the germ-free mashes due to autoclaving. In the germ-free studies cited, the workers did not attempt to enumerate or classify the bacteria of the control birds. Earliest studies on the flora of birds were not quantitative in the sense that there were no tallies of populations of general types, e.g., conforms, enterococci, aerobes, and anaerobes. Enrichment or differential media had not been developed to the extent available today. Identification of Species In 1897 Kern (43) studied 24 birds and identified 88 species of which 32 were motile bacilli, 28 micrococci, 8 sarcinae and 20 species of "bacteria". The work, cited by Gage (29) was not available for study. Rahner (73) found that the population o f Bacterium coli gallinarum increased as the cloaca was approached. Bergey's Manual 6th Edition (7), does not list this name nor is it found as a synonym for Escherichia coll. which the writer assunes it to be. Bacillus megatherium, gram-positive cocci, and lactic acid bacteria were found in smaller numbers. Gage, l o c . c i t .. reported that King (44) found anaerobes, e.g., Clostridium welchil (or perfringens) to be extremely rare. anaerobes found were obligate. Eew of the Bacterium coll. now called Escherichia coli. predominated throughout the digestive tract, but rarely occured in the duodenum. (Hereafter, the names of bacteria given are the present- day equivalents, if known, of the species listed by the authors cited.) Gage (29) studied birds which were allowed to peck at the earth floors of their pens. His finding Nocardia asteroides. Bacillus mycoides. - 5- Bacillus subtills, micrococci and psuedomonads is not unexpected. diplococci (enterococci?) or obligate anaerobes were noted. Few Escherichia coli predominated, but varied in numbers with the environmental conditions and the age of chickens. Gage (29) estimated that about sixty percent of the bacteria were gram-negative. Some difficulty was encountered in distinguishing bacteria from fiber and debris, much of which stained gram-positively. It was assumed that not all bacteria found on the stained (direct) smears of in testinal material were alive at the time of sampling and that many were un cult ivat able with media available at that time. In 1929 Ifenes and Rochlin (59) found the same bacterial species in all parts of the intestine, differences being in quantity. This uniformity of flora was explained on the basis of acid production which suppressed putrefactive Bacteria and their associated decomposition processes. flora producing lactic acid were: The Streptococcus faecalis. Escherichia coll. and Lactobacillus plantarum. the latter being the most prominent anaerobe. Emmel (27) did not attempt to detect anaerobes in the droppings of 20 adult hens. Twenty chickens suffering from enteritis showed a decrease in Escherichia coli. lyphoid-paratyphoid types appeared. Salmonella pul- lorum was invariably found in the intestines of chicks suffering from pullorum disease. The quantitative assay of the predominating bacterial types found in animal,, intestines and feces is fairly recent. Research in this direction was stimulated by the discovery that bacteriostats, especially sulfonamides, when fed to experimental animals in amounts sufficient to depress certain types of flora, e.g., the coliforms, resulted in the appearance of vitamin - deficiency symptoms. 6- (17, 18, 19. See also reviews 23, 24, 64, 70.) These symptoms were relieved by B-vitamin therapy. Although Lewis et al. (48) showed that the mortality rate for chicks was least when Escherichia coli existed at levels over 3,000,000 per gram of feces; deaths were greatest when one percent sulfaguanidine* alone or together with an Escherichia coli suspension or vitamin supple ment was added to the diet. Groschks and Evans (33) initiated chick growth studies on aureomycin and streptomycin after Stokstad (90) reported a mash fermented by Streptomyces aureofaciens contained chick growth factors. No bacterial studies were made, although it was surmised that antibiotics aided in establishing intestinal bacteria favoring greater utilization of nutrients by the chicks. Growth stimulation was reported to be less than that ob tained when a basal diet was supplemented by five B vitamins without vita min B 12, or with five B vitamins and vitamin B 12. The contribution of intestinal flora to the nutrition of animals have been reviewed by Daft and Sebrell, Elvehjem, Johansson. (19, 21, 23, 39.) Because the scope and complexity of the subject are very broad, insufficient data are n o w available to make quantitative estimates of the positive or negative contributions of the normal bacterial flora. This review is limited chiefly to studies on poultry flora as related to bacteriostats and growth-promoting agents. * One percent of body weight per day - 7- Growth Stimulation by Bacteriostats A very surprising phenomenon is the growth stimulation of chicks and pigs by the addition of extremely small concentrations of bacteriostats to diets properly balanced. Quantities are from one-tenth to one- hundredth the therapeutic doses. Moore et al. (62) established tolerance levels for chicks for streptothricin and streptomycin and sulfasuxidine. These additives re duced the eoliform bacteria in the ceca, but did not sterilize the diges tive tracts. At non-toxic levels sulfasuxidine and streptomycin, when folic acid was added to the diet, resulted in a growth stimulation not attributable to folic acid alone. The addition of folic acid, required for normal chick development, replaced that which was ordinarily supplied by the bacteria. Morehouse and Mayfield (63) found that 3 nitro-4 hydroxy phenylarsonic acid o r its sodium salt stimulated the growth of turkey poults when fed at one-fourth the concentrations required to prevent coccidiosis. Bird et_ al. (9) noted that phenyl arsonic acid and the last mentioned compound stimulated chick growth. Other derivatives were not effective. Groschke (32) confirmed the stimulatory effect on turkey poults, but found that antibiotics were far more stimulatory than arsonic acid deri vatives on experimentally raised chicks. Scott and Glista (82) fed individual chicks and found that aureomycin and 3 nitro-4 hydroxy phenylarsonic acid resulted in greater feed consumption, so that feed efficiency was not improved. consumption. That is to say, weight gains reflected increased feed - 8- Stokstad and Jukes (91) also obtained accelerated growth by feeding 3 nitro-4 hydroxy phenyl arsonic acid. Growth resembled that obtained with streptomycin and succinyl sulfathiazole, which were less effective than aureomyein. Severens (83) et al. gave two percent sulfamerazine to pulloruminfected chicks. This resulted in great reduction in mortality and a growth increase over the untreated controls. However, healthy chicks weighed 28 percent more than the sulfa-treated birds. A proprietary anti-coccidial agent, Megasul nitrophenide, at a concentration of 0.0125 percent served to increase weight gains in large flocks of chickens tested throughout the United States. laboratory animals. These were not Growth differences between treated and untreated birds may be due to suppression of intestinal parasites (42). Ingram and Edgar (37) tested streptomycin, aureomyein, penicillin, sulfaquinoxyline, sulfadiazine, nitrophenide, and phenylarsonic acid in diets fed to chicks infected and uninfected with Eimeria tanella. At four weeks the antibiotics gave more than 20 percent growth advantage over the uninfected controls. The other drugs were less stinulatory. therapeutic value in controlling the disease. No drug had Growth of infected survivors paralleled that of the uninfected birds when both were fed antibiotics. The growth stimulation was not due to suppression of cecal coecidiosis. Polymyxin D was tested on a small number of chicks by Peppier et a l . (68). Polymyxin, toxic to humans when given parenterally, greatly affects gram-negative organisms and has a negligible effect on grampositives. levels. It was fed as a charcoal adsorbate at one and one-half percent Although the antibiotic was eluted in the digestive processes, - 9- no polymyxin was detectable i n the blood. Coliforms were markedly suppressed, even for several days following removal of polymyxin from the diet. Streptococcus faecalis was the most resistant type of bacteria. Other lactic acid producers were not affected. Riedel, and others (76) tested quaternary ammonium compounds for their effectiveness in combating ascarids. Alkyl dimethyl benzyl ammonium chloride and alkyl dimethyl dichlor benzyl ammonitm chloride proved to be optimal growth stimulators at 1:2000 levels. pressed growth. Higher concentrations de The intestinal parasites were also stimulated. No bac terial studies were reported. Ely (25) reported that in two of three experiments terramyein, bacitracin and aureomyein were effective in producing more accelerated growth than fat acid-ethylene oxide condensates produced. experiment surfactants appeared to be more effective. gistic effect between surfactant and aureomyein. tinal bacteria In the third There was no syner No enumeration of intes was reported. Within the last two years the reports of substantial growth stimu lation by aureomyein hydrochloride, procaine penicillin G-, bacitracin and terramyein have been numerous. less efficient. Streptomycin and other antibiotics proved Jukes (41) mentioned favorable response of chicks to Chloromycetin and neomycin. Crude preparations derived from fermentation residues are customarily used in commercial feeds and may give results enhanced by nutrilites present in the concentrates. The majority of the reports credit the growth enhancing effect of antibiotics to a supposed alteration of the bacterial flora. But few « - 10- bacterial analyses were made to substantiate the opinions (3, 8, 18, 21, 22, 34, 40), Although not reported in every instance for each antibiotic, the effects common to growth-promoting antibiotics may be summarized as follows: 1, Some water soluble vitamins may be required in lower amounts when antibiotics are incorporated into the diet. Oleson and associates (66) reported mutual sparing action between vitamin B 12 and aureomyein. Biely and March (8) noted a lowered requirement for folacin, niacin and riboflavin. Davis and Briggs (18) found no diminution of vitamin B 12 requirement when four antibiotics were tested. Stokstad et al. (92) found no marked differences in the required levels of water-soluble vitamins when aureomyein was a part of the diet. Blaylock and associates (11) found penicillin and aureomyein to be growth-promoting only when their semi-synthetic diets contained adequate amounts of vitamins. Growth rate in creased when suboptimal quantities of folacin, riboflavin, choline and vitamin B 12 were in the diet. Inadequate amounts of pyridoxine, pantothenic acid or niacin resulted in failure of the antibiotics to promote accelerated growth. I - 2. 11- The animal protein may be eliminated from feeds when small amounts of vitamin B 12 and aureomyein or large amounts of vitamin B 12 are present with adequate plant-proteins in the diet. 3. Total proteins in feeds may be reduced slightly without sacrificing dietary efficiency. This is reported by Maehlin et al. (50), and McGinnis (57). Slinger et al.. failed to confirm this (87). 4. Aureomyein hastened the depletion of vitamin B 12 in hens on experimental "depletion" diets of Halick andCouch, 5. (34). Growth rate of chicks is enhanced up to eight weeks, possibly ten weeks. A summary of the effect of antibiotics on turkey poults was given by McGinnis (58). chicks. These effects apply also to Birds taken off antibiotic feed at eight weeks of age were the same weight at 20 weeks as birds kept on anti biotic feed. 6. The number of runts in a flock was reduced, (58). 7. Mortality rates were reduced, 8. Hatchability of eggs from hens fed aureomyein was improved. (58). Elam et a l . , (21) and Mariakulandai et a l . , (56) were not in agreement with Peterson et al., (71) who failed to show im provement in hatchability of eggs laid by hens receiving suboptimal amounts of vitamin B 12. 12- 9. The numbers and types of intestinal bacteria may be altered tinder some circumstances. At the time when the present study was initiated there was insufficient evi dence to warrant specific conclusions. The Functions of Dietary Antibiotics A characteristic common to reported growth stimulants is their antibacterial activity. However, this activity is manifested at levels considerably higher than are used in feeding experiments. Certainly these compounds, of diverse chemical constitution, do not contribute any common nutrient materials to the experimental animals. Kramke and Fritz (45) found that sulfamethiazine and sulfathiazole did not stimulate growth under conditions in which aureomyein, bacitracin, penicillin and terramyein promoted growth. From this information, and other data, we can infer, first, that the mere ability to suppress bac terial growth (at proper concentrations) is not significant. Secondly, the types of bacteria affected by each of the above-mentioned antibiotics (the antibacterial spectra) are not at all similar. For example, penicillin (at practical levels) affects the gram-positive organisms. Aureomyein and terramyein have broader spectra including both gram-positive and gram-nega tive bacteria. Or, in tennis of intestinal flora, terramyein, in vitro suppressed gram-positive cocci, Escherichia coli and most Aerobacter aerogenes strains. This was reported by Baker and Pulaski (4). fed to rats by Johansson et al. and increased in enterococci. Aureomyein (40) reduced Clostridia and lactobacilli The eoliforms are less susceptible to peni cillin than to the other antibiotics except bacitracin, which does not affect them. - Peppler, et, al. 13- (68), in a limited experiment on chicks, found polymyxin D to depress coliforms markedly but did not affect other lactic acid producers at one-half percent and one percent dietary levels. terococci were resistant. En- Growth was stimulated. March and Biely (55) noted considerable bacterial variations in day to day samples of feces taken from chicks fed diets with and without aureomyein. These enumerations of various aerobic bacteria were not taken from identical samples. Therefore, ratios of types of organisms at a given time cannot be estimated. in numbers. Lactobacilli were the first to be reduced Not until 40 to 80 mg of antibiotics were added per kilogram of feed, was there a significant alteration in total counts or colifoxm indices. This is higher by two to four times the amount ordinarily re quired for growth stimulation. Coliforms were initially depressed in rats and mice fed 2,500 units of streptomycin per gram of rations, as they also were by succimyl sulfathiazole, neither of which were growth promoting. Bnerson and Smith (26) noted that streptomycin had no significant effect on the bacterial numbers in rat and mouse feces. Coliforms reestablished themselves. Mice sustained a reduction in total bacteria in the intestines. A study by Elam and associates (21) revealed stimulation of total anaerobic counts, enterococci and penicillin-resistant bacteria in the feces of hens and chicks fed 33 mg of procaine penicillin G. This is more than the amount required to affect growth stimulation, i.e. ten to twenty mg per kg of feed. Workers in Washington (86) found Clostridium oerfringena in the cecal contents of turkey poults. Potassium penicillin G and terramyein I - 14- (100 ppm each) reduced these Clostridia to negligible numbers. Results were not so well defined with respect to enterococci, total anaerobes or aerobes. Larson and Carpenter (46) fed procaine penicillin to pigs. Fecal bacteria were diminished, particularly Clostridia. However, the growth of the pigs was not related to the numbers of Clostridia detected. Growth stimulation seems not always to be due to antibiotic effects, i.e. the suppressing of some intestinal inhabitants or encourag ing the growth of non-suseeptibles. Elam, Gee and Couch (22) presented evidence suggesting other mechanisms may be involved. caine penicillin G has no antibacterial potency. Autoclaved pro When this penicillin was injected or fed orally to chicks, there was no alteration of fecal flora. But growth rates were increased over those of controls. Parenteral injections of bacitracin also increased rate of growth without affecting fecal flora. Earlier work by Stokstad and Jukes (90) noted that alkali- treated aureomyein residues possessed groth-promoting power but no anti bacterial activity. Whitlock (95) summarized the theories concerning the mode of action of antibiotic feed supplements which were held early in 1951. These theories may be listed as follows: 1. The suppression of Clostridium perfringens may prevent enterotoxemia. 2. Alteration of flora to permit greater activity by bacteria favorable to the welfare of the host. 3. A synthesis of the latter two theories suggests that the former may occur only when high levels of antibiotics are utilized. 4. Antibiotics stimulate the appetite. - 5. 15- Antibiotics increase the availability of nutrients or stimulate intestinal synthesis of these nutrients* 6. Antibiotics may suppress colifonm organisms which utilize nutrients at the expense of the host. 7. Trace minerals present in antibiotic supplements may affect the activity of intestinal flora. 8. Antibiotics effect may be systemic. 9. Effective antibiotics decrease surface tension of the gut. This may result in more effective absorption of nutrients than when antibiotics are absent. 10. Antibiotics prevent the favorable balance existing between animal and pathogens from becoming upset. A low ’’disease level" is maintained. A review of these theories follows in the discussion of experi mental findings. 16- EXFERIMENTAL I. THE EFFECT OF CERTAIN ANTIBIOTICS ON THE INTESTINAL BACTERIAL FLORA OF THE CHICK Methods of Enumeration.: A Review of Media The purpose of enumerating the major groups was not taxonomic with respect to shapes, sizes or species identifications of the bacteria. Interest was slanted toward the grouping of bacteria with respect to their biochemical or biological activities. Earlier workers estimated bacterial species on the basis of fre quency of isolation: Gage (29), Rahner (73), King (44), Menes and Rochlin (59) and Emmel (27). Advances in the study of nutritional requirements of bacteria and the development of diagnostic media - either differential or enrichment has permitted, at least to a limited degree, the estimation of the total number of certain types of bacteria. Laborious and time-con suming fermentation or serological tests are eliminated. The major groups by which intestinal bacteria have been numbered are the aerobic, anaerobic, gram-positive, gram-negative, coliform, lac tic acid group, yeasts and enterococci. Spore forming, non-sporulating and Proteus-like groups have also been mentioned. The sporulating bacteris, Proteus-like rods and yeasts have not been found to exist in large numbers in the chicks as well as in other experimental birds raised in brooders, free from gross contamination from 17- soil and extraneous feed. No media favoring their enumeration war0 following preliminary tests, Typical starter diets seemed not to ed ®r the appearance of large numbers of yeasts. The total count of aerobes has been made on several media. Evenson (2s)» studying rodent flora, used a liver infusion broth chunks of liver settled at the bottom of tubes to permit anaerobes g row also. xro- Thioglycollate medium, a broth which enhances the growth of aerophils was utilized by Elam, e t . al. tract, agar, (2l) • Tryptose glucose ye00** e x (hereafter referred to as TGE) was employed b y Shapir0 Sarles (85), Johansson, e t . a l . (38) and March and Biely ( 55), S i a ^ V l i et al. ( 86). Harrison and Hansen. ( 5 5 ) utilized Eugonagar ( 5 ), a urn designed to obtain growth of fastidious organisms of which Lactoba0*^- i. are the only bacteria found in noticeable amounts in the intestinal The numbers of intestinal bacteria estimated by microscopi0 a ^ u d y of smears are usually far in excess of those tallied by aerobic Discounting the possibility of large numbers of dead organisms bei*^ tallied with those viable, it appears that many fail to develop on ^ i a in current use. Anaerobic media, besides favoring the growth of o h ^ ^ & t e anaerobes, tend to favor growth of some fastidious organisms which best at low oxidation-reduction potentials but which are not neee80a* t ^iy obligate anaerobes. (Of. 6.) Anaerobes resembling Clostridium perfringens have been isolfl^ ^ a . from animal intestines by several workers (8b) (86). Cecal areas 0P^^a.r to harbor far more anaerobes than do the upper portions of the int0fl^i_nal tract. Crecelius and Rettger (16) used a cysteine deep-tube agar timating anaerobes in guinea pig guts. Evenson et al. es (l o c . clt.) I - 18- suspended chunks of liver in tubefuls of a liver infusion broth. The particulate matter serves as minute "nests” wherein some anaerobes may flourish even when the redox potential of the medium may not be at an aerobic levels. Shapiro, et a l . (l o c . cit.) used TGE in 100 percent hydrogen atmosphere. Sieburth, et al. (loc. cit.) employed Eugonagar under anaerobic conditions. thioglycollate medium. Johansson and associates employed BBL Harrison and Hansen (35) noting that many lacto- bacilli grow better under anaerobic conditions used a modified tomato juice agar and trypticase-soy-glucose agar (BEL) under anaerobic condi tions. Anaerobic agar with methylene blue (BBL) was used in this study. The coliform bacteria are of historic interest, particularly be cause they were reported by early workers as being the dominant flora in the gut and also because many animal nutrition studies suggested that suppression of coliform bacteria was related to vitamin deficiencies. The medium chosen by a majority of workers is Levine’s Eosin-Methylene Blue agar. Sieburth, loo* cit., used Difco Violet Red Bile Agar and Evenson, lo c . cit.. the *E. C. medium’1 of Perry and Hajna. A lauryl-tryptose-lactose broth (LTLB) studied by Mallmann and Darby (52) has become an accepted standard medium for evaluating sewage and water supplies (88). A greater index of coliforms is obtained upon confirmatory use of LTLB than when the more inhibitory dyes or bile salts are used. A high degree of agreement between "presumptive” tests and confirmatory tests led the writer to utilize this broth as sole medium for estimation of coliform organisms* The enterococci also have been utilized for estimation of fecal pollution of water, particularly in England. The estimation of these bacteria f l within the intestines has been by the use of Periy-Hajna’s (69) wSFn medium. Researches by Mallmann and Seiigmann(53) show that a lower con centration of sodium azide than that used by Perry and Hajna or Winter and Sandholzer (97) will suppress gram-negative organisms but allow for higher indices of streptococci. When lactose fermentation in the presence of azide is the sole criterion, nearly 99 percent of the portions showing (positives) acid production contain streptococci. Occasionally broth contains gram-positive rods which seldom produce acid under test condition** The appearance of the bacterial mass is such that tubes containing other than streptococci may be easily recognized and discarded for pur pose of establishing probable numbers calculations. The writer chose Azide-dextrose medium (Difco) which is primarily a result of the studies of Mallmann and Seligmann. (See Appendix, p.iii) A large group, not well defined as to nutritional significance in the gut, is the lactic acid group which includes the enterococci and c o n forms as well as lactobacilli. Many grow in anaerobic media, such as a tomato juice agar which contains dextrose and a low agar content. Tryp- ticase-soy-glucose agar (BEL) was used by Harrison and Hansen, (35) and March and Biely(55). Evenson (q.v.) used an acetic acid broth for growing lactobacilli, depending upon low pH to discourage growth of other types. workers (3B), (39), and Sieburth et al. (86) and Elam The Wisconsin et al0 (21) made use of carrot-liver (CL) medium of Garey (30) as shake-cultures. The writer found a 1.2 percent agar adaptation of this medium to be superior to TGE medium. The majority of aerobic assays were made on CL. It was found that adding one of Squibbs’ B-complex tablets (Squibbs’ B-complex formula) which contains 2 mg thiamin hydrochloride, 3 mg riboflavin, 20 mg 20- niacin, 5 grains Natuplex-B, a yeast extract complex, to one liter of carrot-liver medium enhanced counts from ten to more than a hundred per cent. Dehydrated liver (Difco) was used in place of fresh liver which may account for additional vitamin requirement. It was necessary to clarify the carrot and liver extracts by centrifugation immediately be fore preparing the medium. This was to eliminate the confusing of floe with minute sub-surface colonies. Methods of Study; Techniques Gram stains were made of 10”^ or 10“® dilutions of the fecal samples and also of about one hundred of the intestinal samples. The method was that described in Manual of Methods for Pure Culture Study of Bacteria (54), leaflet I V - 51 p. 9, Burke's Modification. Fecal material was obtained by killing chicks within 15 to 30 minutes after removal from the brooders. The birds killed by neck frac ture were dipped in a 1:3000 solution of quaternary ammonium compound to reduce the possibility of sample contamination from loose down. The appropriate sections of gut were manually removed and placed into indi vidual sterile Petri dishes and refrigerated at once. Within 45 minutes the appropriate gut portions were withdrawn from refrigeration and their contents manually expressed into previously weighed containers, i.e. sterile wrapped 50 ml beakers. the gut contents. Care was taken to avoid contamination of From weighed samples, portions approximating 1 to 1.5 grams were removed to sterile mortars by means of a flamed microspatula. Containers were re-weighed and the weights of the assay portions calculated c by difference to the nearest milligram. for two days at 104-110 The remaining material was dried C in an electric oven for calculation of moisture content. The dilution water was added by means of 2 ml pipets in small amounts (l to 2 ml ) in order to obtain homogeneous suspensions. Addition of larger portions of water made it difficult to disperse small clumps which formed. From the primary dilution appropriate volumes were trans ferred to standard milk-dilution bottles which contained 90 or 99 ml of sterile saline solutions. refrigerated until The 10 -2 and 10 -3 ■.ilution oottles were all samples were treated similarly. Subsequent ten fold dilutions were made and portions of each introduced into the various media. Ho common or standard procedures are given by workers assaying in testinal bacteria. livenson bottles to disperse clumps. et_ al. (28) used glass beads in the shaking Bottles were shaken 200 times. Shapiro and Sarles (85) reported using 6 oz bottles with glass beads and occasional use of a haring blondor. Harrison and Hansen (35) used sterile sand when grinding samples. T he w a t e r found sand to aid in dispersing material from small intestines or feces. Cecal and duodenal material, being free from gritty matter, was easier to grind without sand. Careful addition of water and rapid grinding resulted in absence of visible clumps. It is believed that microscopic bacterial clumps were of minor significance in the lower dilutions which were transferred only to liquid media. Staking each dilution 25 times results in con siderable dispersal by the time the higher dilutions are obtained. Dilution and shaking techniques conformed to standard methods for -22- examining water and sewage (88). The method of obtaining feces v/as as follows: group were held and the anal area palpated. Birds in each dietary Feces were collected in sterile wide-mouth tubes (seeding pots) and refrigerated in transit from the noultry plant to the laboratory. Weighing and dilution of feces were as described above. Media were incubated at 37 0 for two days and plates were enumerated with the a i d of a Quebec colony counter. Most probable numbers of c o n forms and enterococci were estimated from tables obtained from Buchanan and Fulmer (12). Except in the preliminary tests, three 1-ml portions of each sample dilution were made. An exception to standard platings v/as the use of about 20 ml instead of 10 ml of the agar were placed in the Petri plates and allowed to harden, after w h i c h the sample portions were added. of war: Approximately 10-ml amounts medium were mired with the sample aid allowed to gel. hardened, an overlay of 5 ml of hot medium v/as made. appearance of surface colonies. As soon as T.iis prevented ‘ The large amount of water of syneresis produced in the confinement of the anaerobic jars made this necessary. Calcium sulfate (Drierite") in three or four Petri plates placed among the culture plates reduced the appearance of excess surface v/ater. Plates could not be inverted because evacuation of gas resulted in displacement of the a g a r . Three anaerobic jars were constructed from SO - qt pressure earners ("All A m erican"). These were heavy aluminum vessels equipped with screw lochs w h i c h effected an air-tight seal of the ground-joint between cover and vessel. Safety valves and pressure gauges were removed and replaced 1 -23- v:itii brass gas cocks. To the inlet cocks pieces of rubber ttibing were taped to facilitate removal of air from all parts of the vessel. Tests on reduced litmus milk, reduced methylene blue (water solution) and ana -rooic agars with Eh indicators revealed that two washings with natural gas followed "by vacuum pump evacuation to pressure equal to about 30 microns of mercury v/ere sufficient to prevent onidation to the indi cators. Ana robic plates were incubated at 3? C , the anaerobic .jars containing natural gas at initial pressures slightly less than atmospheric. Media in plates, which at the time of introduction to the jars appeared slightly oxidized, v/ere invariably found to be in the reduced state when examined two days later. Agar plates were made in duplicate from three appropriate dilutions, viz.; 10 -4 , 10 -6 , 10 -7 (small intestines). averages of two "valid" pirates obtained. Reported data represent By "valid11 is meant plates in which not less than 30 or more than 350 colonies appeared. Occasionally these limits were necessarily extended. In vitro tests of blood serum, arsanilic acid, and intestinal contents were made by means of paper discs or penicylinders on penassay seed agar (Lifco). Cultures used were 24-hour suspensions made from slants seeded with laboratory stock cultures used for antibiotic assays. Bacillus sub- tilis spore suspensions were heat treated (80 C) and used according to procedures commonly accepted by workers assaying antibiotics. Chicks used in the nutrition studies were of the fast-growing large types: Rhode Island Reds and, in some cases, ITew Ha pshires. Chicks selected for studies were those whose weights approached the mean weight of the nrouos. Runts and especially larne birds were excluded from tests I -24- at the end of the preliminary vitamin depletion period. HESULTS Prelimiimry Assays of Intestines of Individual Chicks Table I presents data obtained from examination of four-week chicks taken from larger groups whose average weight gains in two weeks are listed. These chicks were representative of the test groups which were not fed the test diets for the first two-week depletion period. In this sampling only, a single-tube series of broths was employed to estimate the ranges required for future assays. It appears that streptomycin (0.01 percent) tended to depress colifor.ns but not enterococci in the upper part of the intestines, and possioly in the ceca. However the birds in Group 7 (Basal, vitamin 3 12 and strepto mycin) harbored bacteria of widely divergent power to grow on TGE agar. Vitamin ±5 12 tends to favor an increase of coliforns in the duodena and lower small intestines, but with a corresponding reduction in enterococci. It did not increase the flora of the cecum. The significance of these trends is questionable because of the low number of samples tested. Effect on Streptomycin on fecal Flora. fresh, non-cecal feces obtained aseptic.ally from four birds per group were assayed and are reported in Tables II ana III. The groups 1, 2, S, and 7 map- be compared with their streptomycin-supplemented counterparts, groups 8, 9, 10 and 14 respectively. (Table II.) Gram stained preparations reveal considerable increase in grampositive organisms in the chicks fed streptomycin and a decrease in gramnegatives. Ho correlation exists between the numbers estimated by stained I - 25- smears and the tallies of bacteria able to grow on the media employed. It is possible that debris or particulate matter may have been included in the former estimates. Estimates of stained preparations were discontinued in favor of media designed to grow the major groups found by Shapiro and Sarles (loc. cit.) and Harrison and Hansen (loc. cit.). Bacteria were generally depressed by streptomycin. However, this depression was not marked by reciprocal growth rate increase. Effect of Various Growth Stimulants on Bacteria Tests at Michigan State College showed arsanilie acid to be capable of stimulating the growth of turkey poults (32), Chicks fed a similar diet did not respond as did the turkeys. Eeces from two groups of turkey poults were collected from several birds (6) in each group and examined according to the routine method pre viously adopted. Table IV lists the results obtained. appeared to stimulate the growth of enterococci. pressed. Arsanilie acid The coliforras were de The total populations of bacteria were increased by the arsanilie acid. An in-vitro test of the activity of arsanilie acid solutions was made according to accepted procedures for antibiotic assay. Concentrations from 0.1 percent to 0.001 percent haa no effect on a virulent strain of Escheri chia coli. The concentrations approximating those fed to the turkeys stimu lated Bacillus subtilis. (Cf. Table V.) Several organic chemicals were tested for their ability to enhance the growth rate of chicks: cetic acid. tested. indolacetic acid, diphenol indol, ethyl ester of indola- In addition, crude olivacein (from S1?reptomyces olivaceus) was Tests on chicks showed only indolacetic acid to be stimulatory; the 1 - 26- the populations v/ere generally higher at all levels of the intestinal tract than are usually encountered. Sspecially noteworthy (Table VII pp. 7,8) is the high level of enterococci at all levels. The group of indol compounds which were tested tended to raise bacterial levels, particularly in the upper portion of the intestines. Porter (72) cites work in which indolacetic acid v/as shown to have been utilized in synthetic media for Neisseria gonorrheae (p. 715). Tscherichia coli is capable of forming indolacetic acid whereas Proteus vulgaris and Oidium lactis produce B-indolacetic acid from tryptophane. The latter acid is heteroauxin, a plant hormone which, in 1/50,000 to 1/30,000,000 dilutions, is capable of stimulating Bschorichia coli and Salmonella tvohosa. Indolacetic acid has been shown to inhibit the enzyme penicillinase (p. 596). This suggests that its use in conjunction wit... penicillin might be synergistic. substitute for tryptophane. Its effect 0.1 0 ns seems to be as a Tryptophane is required for niacin synthesis. However, all the feeds containing indol-compounds failed to elicit growth as great as chat obtained from the control diet (Basal plus 3y percent vitamin 3 12). Olivacein obtained from Streptomyces olivaceus was used in crude form.' It did not enhance the growth rate of chicks nor did it seem to inhibit the bacteria], flora, of their guts. Compared to populations of the birds fed Penicillin or basal-plus-vitamin B 12 diets, the olivacein-fed birds showed considerable enhancement of populations (Table VIII, p. 8). Noteworthy is the large number of enterococci in the small intestine. An in vitro disk assay by the following organisms on 0.1 to 0.001 per cent solutions of the cru e olivacein showed neither antibiotic nor stimula- I -27- tory activity: Lactobacilluscasei, L. arabinosus, L. leichmanii, Leuconostoc-mesenteroidesi Aerobaoter aerogenes, Proteus vulgaris, Bacillus subtilis, Escherichia coli and Streptococcus faecalis. mentioned do not grow well on Difco Penassay Seed Agar. (That first four Second trials v/ere made using a modified Tomato Juice Agar for the lactobacilli.) Effect on Procaine Penicillin on Intestinal Bacteria Procaine penicillin G v/as found to promote growth of chicks at levels one-fifth to one-tenth the amounts required for equivalent response to streptomycin. Chicks v/ere selected from groups fed basal diets supplemented with graded amounts of vitamin B 12 in crystalline form and also in crude form referred to in fable VIII as "P.P. B 12", a concentrate of dried fermentation solubles. An inspection of Table VI reveals a tendency of penicillin to restrain development of bacteria in the upper intestine, especially the enterococci which are knovrn to be penicillin-sensitive. Cecal flora v/as not so markedly affected, excepting the cocci. Fecal samples v/ere obtained from several birds in each group. Because it v/as impossible to obtain intestinal samples large enough to assay for both water content and bacteria the remaining experiments v/ere based upon pooled one samples from four chicks per dietary group. (Samples approximating ram v/ere employed to reduce the degree of error introduced by assay operations.) This also tends to minimize the wide fluctuations in counts between individual birds. (Cf. Shapiro and Sarles, 64.) Table VIII and Fig. 1 reveal no consistent maintenance of bacterial levels within groups although cecal flora tend to be less variable. This DIET BASAL BASAL 6VITAMIN B-12 BAS.&PEN. BASALB-I2& PEN m Ui S A M P L IN G D A TE LEGEND FIG.I-A DUODENA -O COLIFORW _E ENTEROCOCCI EFFECT OF PENICILLIN ON FLORA X PLATE c o u n t s DIET BASAL SAMPLING BASAL&VITAMIN B-12 BAS.a PEN. BASAL,JB-12 a PEN DATE ^ l' e g e n d FIG.I-B LOWER SMALLl-NTESTINES 0 COLIFORM E ENTEROCOCCI E F F E C T OF PENICILLIN ON FLORA X PLATE COUNTS B A S A L S V IT A M IN BASAL D IE T B -1 2 B A S A L ,B I2 a BAS. a PEN. P E N . 10 • \ N . / .» • -■ * * ‘ ••X 9 m M -J 1 < 0) o u -J o ? O) w e K UJ > « e' o _j * M / f a • A . ‘ J) f t . - X . .* A * *•« / > & \ # ' t V e \ 1 a f / < & V « \ e r \ h n* / \ # % I '6 * r i •fc 4 /• i \ * 1 SAMPLING 1 / V 1 DATE i* M \ u v * y t LEG E N D FIG.I-C C E C A ---------O C O L IF O R M S ---------E E N T E R O C O C C I E FFECT OF PENICILLIN ON FLORA — x PLATE COUNTS -28- is in agreement with the findings of Shapiro and Sarles who studied two chickens from "‘birth11 for thirty weeks. They assayed bacteria major classifications weekly or bi-weekly. of all four Variations in numbers from time to time deviated by at least ten-fold, frequently more than one hundred-fold. The majority of chicks were assayed at four weeks' age, a few at six v/eoks. These may be compared with no real differences in the amounts the others,since Shapiro and Sarles noted of bacteria (per gram) at any age, once the flora became established (in 37 hours). In an effort to relate quantities of bacteria to growth rate, the dietary groups were placed in five classes representing the greatest to the least growth responses without regard to diet. ains and others for total weights. Four weeks weight: Some lotswere averaged for weight The following categories were established: Class 5, under 100 g, class 4, under 110 g, class 3, under 120 g, class 2, under 130 g, class 1, over 130 g gain. At six weeks the corresponding weights were 360 g, 390 g, 420 g, 450 g, and 475 g. Loga rithmic averages for individual sampling are given Table VII. bacteria were most numerous in the poorest growing birds. Generally, the An appraisal of Table X reveals that the trend is for bacteria to be most numerous when chicks are growing rapidly or when growth rate is slowest. This suggests the possi bility that in the former cases the digestive processes of the chicks are so efficient that a supply of nutrients is available for bacterial proliferation, m the latter case the bacteria may be robbing the host of nutrients. Data presented in Table XI reveal no marksd differences in water content oetween ingesta from diets containing penicillin and those free from penicillin, -or this reason bacteria, were not calculated on a dry weight oasis. Effect of Penicillin on Surface gension and pH A news report in Chemical and Engineering Hews (2) cited nn.publish.ed work by Stern et al. Certain detergents (fatty acid derivatives and quaternary ammonium compounds) failed to stimulate chick growth consistently. These were fed at concentrations from ten to one hundred times that of eenicillin, which v/as far more stimulatory to growth. These workers found that penicillin does not lower the surface tension of feed in vitro. But intestinal contents of chicks fed oenicillin-supplernented diets had signi ficantly lower surface tensions than those receiving control diets. A number of detergents tested at Michigan State College failed to accelerate growth comparable to that of penicillin-fed chicks. One of these, 11'Tide11, is reported in Sable VIII. Ton-fold dilutions of intestinal contents of four-week chicks fed control nets, basal plus 10 ppm procain penicillin G, and basal plus 1000 ppm Ethomid ,J/l (Armour) we re prepared. ritn distilled water. Samples v/ere. weighed to the nearest mg and diluted After being thoroughly shaken the samples v/ere allowed vo settle and v/ere refrigerated until all samples v/ere prepared. Tubefuls oi the dilutions v/ere rapidly brought to room temperature and tested on Cenco -esearch-type Du-Eouy -rule .-jlI. -e:vo li. tensiometers model 70530. The results are given in Values found in Experiment I were slightly higher than in ExperiThis may be due to differences in the basal diets. oo the feed used in Experiment II is listed in the Appendix. dr.tp.nt portions of the diluted samples v/ere tested. The compostion Only the super- Acidity v/as measured clocir ometri cal ly. Penicillin showed a slight tendency to restrain acid production in the -uodena and small intestines out data on cecal mate.-lad are equivocal. The same may be said for cecal surface tension. Surface tensions of duodenal mucus v/as not consistently altered, "but that of the small intestines was depressed. Ethomid C/l5, which in water solution (0.1 percent) has a surface tension of 31 dynes per cm v/as less effective than penicillin in all areas tested. Cecal areas possessed higher surface tensions than those of control "birds. Further studies appear1 to "be required to establish statistically significant data. Miscellaneous Tests In vitro plate assays of the sera obtained from four mature chickens of which two v/ere fed penicillin diets demonstrated no antibiotic activity upon penicillin-sensitive organisms. Full strength sera v/ere placed in penicylinders for assay. Similar assays were made by soaking filter paper discs in undiluted intestinal contents. Ho antibiotic activity v/as observed. Discussion Johansson and Sarles (39) have stated that the ecological system of intestines is delicately balanced and very complex. itself poorly to analysis. They also state: It therefore lends "he know that there are numerous influences on the types, numbers and activities of intestinal microorganisms, e.g., diet .... pH, Eh, the animal species, the normal digestive activity, and possibly other factors (surface tension, mineral concentration, natural metabolic antagonises, synergisms, end age of the animal)11, (p. 40). To these may be added other uncontrollable factors v/nich apply to obtaining a sample. Peristalsis alters the amount of -31- material obtainable from any limited, portion of the intestine. Hecency of d vacation and habits of eating also affect the nature of the samples. Nevertheless, certain information has been obtained which warrants re-enaaination of some of the theories proposed to explain the mode of action of penicillin: 1. Suppression of Clostridium perfringens and related toxemia. Few workers have found perfringens to be present in chick intestines when birds were restricted to brooders or kept from extraneous sources of contamination. Ho anaerobes resem bling the Clostridia were isolated from 242 colonies picked at random from agar plates representing high dilutions of samples from chicks in each dietary group. (The majority iso lated resembled Escherichia coli var. intermedium and Lacto bacillus bifidus or cauce.sicus. were tentatively identified). diarrhea. A fevr micrococci end Proteus Ho chicks showed symptoms of If penicillin prevents enterotoxemia the result is indirect, since it is recognized that thrifty animals with normal flora usually resist pathogenic invasions effectively. 2. Antibiotics stimulate the appetite. A survey of pertinent literature previously reported reveals slight increase of feed intake per unit of time by antibiotic-fed birds. However, efficiency ratios, i.e. - pounds of weight gained per pound of ingested feed are greater when the customary antibiotic supplements are employed. The net result is a saving of feed. I In the case of crude preparations, it rear "be true that trace minerals are present and exert an influence on the "oacterial flora. However, pure crystalline penicillin and aureoraycin map he injected into the “blood strea . or added to feeds. t’-is form they promote growth. In Unless the various secretory membranes are especially permeable to trace minerals, there seems to 'oe no evidence of their effecting intestinal flora, of the chicks. Eke "low disease level theory" nay possibly apply to non experiment al groups of animals or fowl which are probably more frequently challenged by pathogens. Zxperimental animals and fowl are limited to specific diets and maintained under conditions unfavorable to infection by pathogens. It is, of course, recognised that thrifty animals (such as are favored by antibiotics) resist disease. But since levels used are far below therapeutic doses, the reduction of mor tality seems not to be due to antibiosis. The consistent suppression of the coliform group of bacteria has not been demonstrated. In fact, the coliforms have been demonstrated to produce riboflavin, thiamin, niacin, brotin, p-amino benzoic acid, folacin and vitamin K, some of these in excess of their own requirements. cited.) (See reviews previously The ecology of the gut appears to be so complex and obscure that simoie exclamations of this sort are unwarranted. -S3 - The absorption of nut-rients from the chick gut is relieved to take place in the cecum and small intestine. The duodenum, although its villi are longer then, elsewhere in the gut, considered to be chiefly secretory and digestive - a sort of extension of the gizzard. (14, IS). The write'r has never found material resembling chick feed within the duodenum. Probably the passage of ingesta is so rapid through this area, that the feed becomes located in the small intestine immed iately after the chick is sacrificed. It seems apparent that bacteria even in somewhat elevated quantities do not affect absorption in the upper level of the tract, v.'olterink et si. (98) noted a more rapid absorption of radio phosphorus (phosphate) and radiocobalt (cobaltic) in chicks fed penicillin supplemented diets than v/as absorbed by control chicks. One function of bile salts has been described as aiding the dispersal of lipides to effect improved digestion. This, at least in part, is a result of surface-tension activity. Reports of surface-tension activity by penicillin and growth stimulat ion by a few surfactants suggest the possibility of greatly altering concentrations of materials at the interfaces between enzymes and substrates, or the absorbing membrane and nutrients. The mechanism of surface tension depression must not be consider ed without reference to the physiological or biochemical effects of the chemicals utilized. The excellent review by Lawrence (47) lists numerous effects of surfactants upon microorganisms. Some I of these effects are related, to the chemical characteristics of the agents. Studies on the effects of growth-promoting detergents, includ ing certain antibiotics upon digestive juices may he required to evaluate the significance of surface tension depression. 7. Consistent or considerable alteration of flora by growth stimu lators has not been demonstrated in the absorptive areas of the intestines. It must he noted, however, that environmental conditions do affect the metabolic activities of bacteria while they maintain their identity when cultured on diagnostic media.. She possibility of alteration of vital processes with out affecting the ability to reproduce led the writer to per form exploratory experiments which follow -35- THE EFFECT OF DIETARY PENICILLIN G H PRODUCTION OF C3RTAIM B-VITAI-UHS Introduction Biely (8) suggested that the acceleration of chick growth hy feeding the chicks antibiotics may be due to alteration of the activities of the intestinal flora so that vitamins or other essential nutrients become more available than when no antibiotics are included in diets. It was believed desirable to perform exploratory tests of this hypothesis by analyzing chick intestinal contents for certain B vitamins and also to assay in vitro dialysis of B vitamins in a "synthetic gut" apparatus. In vitro studies on rumen bacteria have produced techniques for studying mired flora within dialysis sacs utilized as synthetic rumens (36, 49). ’/asserman (93) studied the effect of several bacteriostats and antibiotics upon cellose digestion by rumen microorganisms in vitro. This work suggested a method for evaluating the effect of penicillin on vitamin production by flora of hens' cecal feces added to a typical chick starter diet. EXPERIMENTAL Apparatus and Methods The equipment for vitamin analysis consisted of the usual glassware and electrometric titration instruments. All assays were made by measu ring acid production by bacteria sensitive to graded amounts of biotin, riboflavin, niacin, vitamin B 12 and folacin. ard procedures (60). Methods conformed to stand Details regarding bacterial species and media-, are -36- given in the Appendix. A series of four simulated intestines v/ere employed in each experimental run. Eight of each v/ere made so that one group might he cleaned and prepared while others v/ere in operation. Fig. 2 is a be- tailed drawing of one of these apparatuses. She feed-v/ater slurry v/as mixed with pancreatin, adjusted to approxi mately pH 8.2 and incuhated at 37 0 for four hoars. This v/as followed hy introduction of fresh cecal feces obtained from chickens which had no knov/n previous contact with penicillin. in a Haring Blender. The mass v/as thoroughly mixed The mixture v/as settled or centrifuged to remove air and divided into two equal portions: one being the control and the other mixed hy blender with appropriate amounts of procain penicillin G solution. The pH v/as adjusted with hydrochloric acid to approximately 6.3 to 7.0 before feces v/ere mixed with the feed. served as buffer. Bisodium phosphate The feed formula and also the details of feed-v/ater slurry preparation are given in the Appendix. Ilitrogen gas passed through pyrogallol v/as bubbled into the dialy sis sac contents to displace air and to keep the slurry agitated during the incu'bation-dialysis period. Two 50-ml volumes each of control and penicillin slurries v/ere funneled into four dialysis sacs each suspended in 800 ml distilled water Hide mouth jars into which the apparatuses were suspended v/ere painted black at the tops to exclude light. The lower portions v/ere kept below a black spacing board which excluded much light. The lower parts of the jars v/ere not painted in order to permit periodic visual inspection. PULLEY 1 PULLEY 2 GAS O U T L E T 3 K J E L D A H L BULB 4 WATER S E A T 9 5 F IL L IN G T U B E ?mm 6 GAS I N L E T 7 NO.6 STO P PE R 8 2 - 1 / 2 "C O R K Vs. 9 SPACING BOARD 10 F EE D M IX T U R E I I GAS D IS P E R S E R 12 C E L L O P H A N E SAC 15 13 D I S T I L L E D W A T E R 14 I 7 0 0 ML 15 STIRRER J AR S C H E M A T IC DRAWING OF APPARATUS FI G. 2 -A o NITROGEN TANK O VALVE (J) PYROGALLOL, 4 5 0 ML. O PYROGALLOL, 4 5 0 M L . (j) C I T R I C ACID, 3 0 0 M L . HEATER .41 C CL V. \ f PINCH COCKS 11 i>
-{••/''.'iuW
>i! \
■ f
/■!
siilliS
-48-
87.
Slinger, S. J., J. E. Bergey, Vi. F. Pepper and D. Arthur, 1951.
effect of antibiotics on the protein requirements of broilers.
Poultry Sci. 50:
936.
The
88.
Standard Methods for the Examination of Water and Sewage, 9th Ed.,
1946. Amer. Pub. Health Assoc., New York, N. Y. (p. 188).
89.
Stern, J. R., J. M. Sieburth and J. McGinnis, 1952. Lack of growth
response of turkey poults to certain antibiotics and bacteriostatic
agents. Poultry Sci. 31: 179-180. (Res. note.)
90.
Stokstad, E. L. R, and T. H. Jukes, 1950. Further observations on
the "Animal Protein Factor". Proc. Soc. Exp. Biol. Med. 73: 523.
91.
Stokstad, E. L. R. and T. H. Jukes, 1950. Growth promoting effect
of aureomycin on turkey poults. Poultry Sci. 29:
611-612.
92.
Stokstad, E. L. R., T. E. Juices and H. P. Broquist, 1951. The effect
of aureomycin in the requirements-of chicks for various water soluble
vitamins. Poultry Sci. 30: 931. (Abst.)
93.
Wasserman, R. H . , 1950. Thesis, Michigan State College. The effect
of certain antibiotics, crystal violet and sodium azide on the "in
vitro" cellulose digestion by ruminant microorganisms.
94.
Whitehill, A. R . , J. J. Oleson and B. L. Hutchings, 1950. Stimu
latory effect of aureomycin on the growth of chicks. Proc. Soc. Esq?.
Biol. Med. 74: 11.
95.
Whitlock, G. P., 1951. Mode of action of antibiotic feed supplements
in poultry and animal nutrition. Feed Age 1: 37.
96.
Williams, R. J., R. E. Eakin, E. Beerstecher, Jr., W. Shive, 1950,
The Biochemistry of B Vitamins, New York, Reinhold Pugl. Corp.
97.
Winter, C. E. and L. A. Sandholzer, 1946. Recommended procedure for
detecting the presence of enterococci. U. S. Dept. Interior, Fish
and Wildlife Service, Commercial Fisheries. T. L, 2.
98. Wolterink, L, F., R. Ogle, R. Kraay and A. C. Groschke, 1951. The
effect of vitamin B 12 and penicillin on the absorption and distri
bution of radiophosphorus and radiocobalt in chicks. Paper presented
at 55th ann. meeting Mich. Acad. Science, Arts and Letters. March
23, 1951 (Mimeographed.)
TABLE I - PRELIMINARY EXAMINATION OP CHICK INTESTINES
Bacterial Numbers Per Gram (wet)
A t . Wt.
Gain
Grams (1)
76.3
Diet
Basal (2)
Basal
Basal plus
3 Y fa B 12
(2)
Basal plus
3 Y $> B 12
102450
Birds
2018
Duodenum
105
105
200,000
Small
Intestine (!)
105
105
1,500,000
Cecum
108
107
850.000.000
Duodenim
104
105
70,000
Small
Intestine
105
10®
1,000,000
Cecum
107
107
27.200.000
Duodenum
106
104
310,000
Small
Intestine
105
103
60,000
Cecum
107
10®
170.000.000
Duodenum
106
103
23,000,000
Small
Intestine
10®
102
2,000,000
Cecum
107
104
128.000.000
2024
102450
Birds
2034
2036
Gp. 2
1.
2.
Plate Counts
Aerobes
TGE
Sample
. Gp. 1
145.2
Most probable numbers
Coliforms
Enterococci
Group
In this and the following tables ’’small intestine” refers to the small intestine below duodenum.
"Y” is gamma or micrograms. Yfo is micrograms per 100 g.
Table I - Continued
Av. Wt.
Gain
Grams
Diet
Group
Sample
Most Probable Numbers
C o nf or m s
Enterococci
156.1
Basal, 3 Y #
B 12 and
0.01# Stretomyc in
102750
Birds
2090
Duodenum
104
105
— «»
Small
Intestine
105
105
100,000
Cecum
104
107
300.000
Duodenum
103
105
2,080,000
Small
Intestine
103
■7
10 7
4,775,000
Go. 7
Cecum
105
10?
89.000.000
102750
Birds
2098
Duodenum
103
106
575,000
S u b 11
Intestine
105
10 6
725,000
Cecum
105
10*
2.400.000
Duodenum
105
103
30,000
Small
Intestine
103
103
20,000
Cecum
10?
106
6.000.000
Basal, 3 Y #
B 12 and
0.01# Strep
tomycin
Basal, 4#
whey, 0.01#
Streptomyc in
152.1
Basal, 4#
whey, 0.01#
Streptomycin
2094
2099
Gp. 8
1.
2.
Average of group at four weeks.
Basal A plus vitamin mix*
Plate Counts
Aerobes
TGE
TABLE II - EFFECT OF STREPTOMYCIN ON BACTERIA IN CHICK: FECES
Pooled Samples Expressed from Live Birds
Counts given in millions per gram (wet)
D i e t
Gp.
TGE Agar Plate
Coliforms
Enterococci
.
Cocci
-
Gram Stain (l)
Rods
/
.. " 7
Short Rods
-
Basal (2)
1
104.00
14.00
1.40
23.4
18.0
16.9
12.8
12.8
7.7
Gp. 1 plus
3 Y # B 12
2
30.00
14.00
1.40
10.1
14.4
23.4
9.0
19.8
1.8
Gp. 2 plus
vit. mix
3
29.00
15.00
0.45
46.6
27.3
3.6
9.0
18.0
1.8
Gp. 3 plus
4$> lactose
7
16.00
110.00
1.40
28.8
16.2
16.2
Gram-positive:: 57.25
Average:
6.27
14.00
1.10
282.6
12.6
23.4
Gp. 2 plus
streptomycin 9
2.45
0.95
11.00
52.2
32.4
5.4
Gp. 3 plus
streptomycin 10
5.44
2.50
11.00
277.2
0
Gp. 7 plus
streptomycin 14
29.00
0.95
0.25
165.6
0
Gp. 1 plus 8
streptomycin
Average:
1,
2.
Average ten fields smears made from 1:100 dilution.
Basal "A* without vitamins.
0
3.6
9.0
0
Negative: 36.70
7.2
7.2
0
54.0
12.6
9.0
0
18.0
0
23.4
0
9.0
0
Gram-positive: 231.75
Negative: 17.1
TABLE III - EFFECT OF STREPTOMYCIN ON BACTERIA IN oHICK FECES
Log Averages of Numbers Per Gram (wet)
Number
of Birds
Diet
Most Probable Numbers
Colifoms
114
(24)
samples
Various diets (whey,
fish solubles, vitamin
mix, etc.) with no
antibiotic added.
138
(24)
samples
Same diets with
streptomycin
added.
Enterococci
Plate
Counts
Number
of Birds
Aerobic
Gram Stain
(Millions)
Positive
Negative
43,750,000
3,719,000
37,030,000
114
241
31
13,200,000
2,610,000
14,120,000
138
162
34
TABLE IV - BACTERIAL FLORA OF TURKEY FECES
Experiment I
Birds
Diet
Pooled
Samples
Basal diet plus
0.0071% arsanilic acid.
Pooled
Samples
Basal only
Most probable numbers
Coliforms
Enterococci
Plate Counts
Aerobic
Anaerobic
400,000
9,500,000
34,000,000
80,000,000
65,000
4,500,000
26,000,000
27,000,000
Experiment II
Pooled
Samples
Basal plus 0.0071%
arsanilic acid.
Pooled
Samples
Bas al only
45,000
25,000,000
103,000,000
132,500,000*
192,000,000
760,000,000*
450,000
4,500,000
33,500,000
53,000,000*
88,000,000
270,000,000*
* Same medium enriched with B-conplex vitamins#
TABLE V - ACTIVITY OF ARSANTLIC ACID ON BACTERIA IN VITRO
Action on Bacillus subtills
Concentration of
Arsanilic Acid.
0.1$
0.05$
Zone of
Inhibition
16 mm.
16 m m
12 nm
stimulation
0.01$
stimulation
stimulation
0.05$
0 .001$
none
stimulation
none
none
none
none
none
none
Action o n Escherichia coli
Zone of
Inhibition
none
none
none
none
none
none
TABLE VI - BACTERIAL FLORA OF CHICK INTESTINES
Group
10551
Bird
3651
Diet
Basal "A" (l)
Basal plus
.002$ Peni
cillin
Gp. 3
10451
Bird
4242
Basal plus
B 12 (3Y %)
Gp. 5
Most probable numbers per gram
Conforms
Enterococci
Aerobic
Plate Counts
Anaerobic
Av.
Gain (2)
Grams
400
400
1,000,000
20,000,000
140,000,000
45.000.000
557,550,000
250,000
Cecum
11,000,000
110,000,000
5,386,500,000
1.449.000.000
Feces
110.000
14.000.000
1.100.000
2.550.000.000
Duodenum
400
400
100,000
10,000
Small
Intestine
250
4,500
800,000
920,000
Cecum
140,000,000
250
1,100,000,000
371,700,000,000
Feces
2.500.000
75.000
2.000.000
3.000.000
450,000
4,500,000
3,969,000
3,230,000
Small
Intestine
14,000,000
14,000,000
270,900,000
327,600,000
Cecum
14,000,000
14,000,000
2,205,630,000
4,725,000,000
Feces
14.000.000
14.000.000
1.606.500.000
3.748.500.000
Duodenum
Small
Intestine
Gp. 1
10351
Bird
4364
Sample
Duodenum
73.9
84.0
126.4
Table VI - Continued
Page 2
Group
10451
Bird
4168
10551
Bird
3617
10551
Bird
3956
Diet
Basal "A”
plus B 12
(3Y fo)
Penicillin
.002 f>
Gp. 7
Basal 3Y £
B 12, Peni
cillin .002 %
plus 3 %
Lactose
Gp. 10
Sample
Most probable numbers per gram
Coliforms
Enterococci
Aerobic
Plate Counts
Anaerobic
Duo den urn
400
700
790,000
690,000
Small
Intestine
900
45,000
6,460,000
7,000,000
Cecum
11,000,000
250,000
18,000,000
48,000,000
Feces
14.000.000
250.000
50.000.000
64.500.000
2
90
100,000
100,000
90
200
5,000
10,000
Cecum
300,000
9,500
101,500,000
185,000,000
Feces
4.500.000
1.500.000
156.870.000
46.400.000
2
250
2,520,000
2,250,000
250
250
1,590,000
2,400,000
Duodenum
Small
Intestine
Basal plus
3Y £ B 12
Pencillin
.002 1o.
Small
Intestine
Gp. 9
Cecum
250,000,000
15,000
522,900,000
126,000,000
Feces
1,500.000
4.500.000
957.600.000
1,102,500.000
Duodenum
Ave.
Gain
Grams
136.8
138.0
137.9
Table VI - Continued
Page 3
Group
10651
Bird
Diet
Basal "A"
plus 3Y £
Vit. B 12
Gp. 5
10651
Bird
4010
1.
2.
Basal 3Y $,
B 12 plus
.002 £ Peni
cillin plus
4 fo Raw po
tato starch
Gp. 11
Sample
Most probable numbers per gram
Coliforms
Enterococci
Aerobic
Plate Counts
Anaerobic
Duodenum
450.000
450,000
2,712,150
2,529,450
Small
Intestine
90,000
95.000.000
56,700,000
7,994,700
Cecum
250.000
20.000.000
4.819.500.000
2,494,800,000
Feces
11.000.000
4.500.000
1.474.200.000
10.615.500.000
2
40
100,000
450,000
750
4,500
350,000
100,000
Cecum
25,000
1,110,000,000
120,000,000
5,350,000,000
Feces
950.000
450.000
10.000.000
30,000.000
Duodenum
Small
Intestine
No vitamins added.
Weight gains at four weeks.
Av.
Gain
Grams
126.4
131.4
Table VI - Continued
Page 4
STMIAHF
Log. Averages Per Gram (wet)
Diet
Without
penicillin
Sample
With peni
cillin
Plate Counts
Anaerobic
3,160
1,288,000
3,266,000
224,400
5,675,000
58,880,000
1,259,000
Cecum
3,112,000
8,185,000
776,300,000
557,200,000
Feces
2.564.000
9.594.000
137.400.000
4.656.000.000
10
145
275,000
233,900
328,100
2,150
427,600
268,500
Cecum
4,920,000
299,700
166,000,000
1,172,000,000
Feces
2.951.000
355.000
451.900
494.300
Duodenum
Small
Intestine
5 groups
Aerobic
1,650
Duodenum
Small
Intestine
3 groups
Most probable numbers
Coliforms
Enterococci
TABLE VII -
RELATION OE CHICK GROWTH TO BACTERIAL FLORA
Log. Averages of Numbers Per Gram (wet) of Samples from Individual Chicks
DUODENA
Weight
No. of
Coliforms
Enterococci
Aerobes
Class
______ Birds_________________________________________________________
Anaerobes
•
1
2
3
4
5
4
2
5
6,714
158
17,740
354,800
1,465,000
514,000
1,321,000
2
100
100
316,200
4,477
351
8,995
1,782
2,065,000
366,400
19,140,000
197,200
2,858,000
187,100
449,800
21,135,000
479,700
445,600
2,238,000
103,500,000
294,500,000
278,000,000
345,900,000
SMALL INTESTINE
1
2
3
4
5
4
2+
5
CECA
1
2
3
4
5
4
2^
2
2,128,000
1,659,000
39,260,000
166,000 2,432,000,000
23,230,000,000
FECES
1
2
3
4
5
4
2+
3,076,000
12,390,000
933,300
93,110,000
7,943,000 1,932,000,000
________ 2______________ 523.600__________ 1.025.000
* No groups were in this class.
- 99,770,000
6,310,000,000
1.483.000___________ 87.500.000
TABLE VIII - BACTERIAL FLORA OF CHICKEN INTESTINES
Group
Diet
Sample
11751
Birds
4446
4449
4452
Basal "A" (l)
only
Duodenum
11951
Birds
4518
4524
4521
11951
Birds
4490
4493
4499
11751
Birds
4563
4564
4567
4572
1.
2.
Small
Intestine
Most probable numbers per gram
Colifonns
Enterococci
Plate iCounts
Anaerobic
Aerobic
250
25,000
10,000
110,000
25,000
2,500,000
100,000
740,000,000
1.400.000.000
1.100.000.000
8.190.000.000
18.900.000.000
Gp. 1
Cecum
Basal "A" (l)
and .002 fo
Penicillin
Duodenum
250
40
620,000
810,000
Small
Intestine
250
40
850,000
583,000
25.000.000
25.000
320.000.000
286.650.000
450,000
4,220,000
53,233,500
Gp. 7
Cecum
Basal "A" (l)
plus 3.2Y jo
B 12
Duodenum
95,000
Small
Intestine
4,500
450,000
8,473,000
7,434,000
45.000.000
14.000.000
175.000.000
220.500.000
25,000
25,000
620,000
810,000
140,000
250
850,000
419,000
15.000.000
45.000
320.000.000
295.000.000
Gp. 5
Cecum
Basal "A" (l)
plus 3.2Y %
B 12 plus
.002 #
Penicillin
Duodenum
..PP.- 1 1 _________
Small
Intestine
Cecum
Av.
Wt.
Gain
Grama (2)
68.3
118.7
127.3
.
No vitamin mix added.
Birds depleted two weeks, then fed indicated diet two weeks.
139.8
Table VIII - Continued
Page 2
Group
Diet
Sample
13151
Birds
4614
4616
4622
4623
Basal ’’A"
plus 0.7Y ia
B 12
Gp. 2
Cecum
13151
Birds
4687
4688
4691
4695
Basal "A"
plus 0.7Y $
B 12 plus
0.002 % Peni
cillin G
Gp. 8
Duodenum
20251
Birds
4651
4653
4654
4655
Basal "A"
plus 5.6Y £
B 12
20351
Birds
4723
4724
4725
4728
2.
Most probable numbers per gram
Coliforms
Enterococci
Aerobic
Plate Counts
Anaerobic
Duodenum
400
400
10,000
10,000
Small
Intestine
400
400
10,000
10,000
40.000.000
20.000.000
85.000.000
8.505,000,000
140,000
25,000
4,252,500
4,567,000
25,000
40
10,000
10,000
Cecum
250.000
250.000
1.000.000
146.160.000
Duodenum
450,000
25,000
270,000
285,000
75,000
14.000.000
11,340,000
23,600,000
Small
Intestine
Small
Intestine
Gp. 5
Cecum
2.500.000
95.000.000
215.000,000
5.827.500.000
Basal "A"
5 .6Y £ B 12
plus 0.002 ia
Penicillin
Duodenum
1,100,000
250
352,800
1,400,000
Small
Intestine
. 1,100,000
90
9,733,500
15,500,000
Gp. 11
Cecum
95.000.000
9.000
129.780.000
1.900.000.000
Birds depleted two weeks, tben fed indicated diets two weeks.
Av.
Gain (2)
Grams
97.9
111.8
106.3
132.4
Table VIII - Continued
Page 3
Group
Sample
Diet
Basal"D"
33151
Birds
5337
5348
5354
5358
Duodenum
Small
Intestine
33151
Birds
5334
5315
5316
5319
40251
Birds
5107
5112
5113
5123
40351
Birds
5205
5214
5283
5225
3.
Most probable number per gram
Coliforms
Enterococci
Aerobic
Counts
Plate 1
Anaerobic
90
9,500,000
31,560,000
2,555,000
2,500
450,000
250,430,000
554,400,000
140.000.000
4.500.000
560.000.000
2.710.000.000
Gp. 10
Cecum
Basal »D»
plus Tide
.05 %
Duodenum
950
2,500,000
45,600,000
19,900,000
Small
Intestine
950
450,000
103,320,000
131,670,000
40.000.000
250.000.000
1.060.000.000
2.140.000.000
950,000
2,500,000
23,000,000
1,000,000
2,000,000
1,400,000,000
1,127,000,000
459,900.000
950.000.000
950.000
540.000.000
1.452.000,000
25,000
4,500
720,000
1,200,000
Gp. 9 ....
Cecum
Basal "D"
plus peni
cillin 2 mg
1 lb.
Duodenum
Gp. 1
Cecum
Basal "D"
plus Baci
tracin
2 mg 1 lb.
Duodenum
Small
Intestine
11,000,000
250,000
3,900,000
8,900,000
GP* 5
Cecum
45,000.000
9.500.000
295.000.000
485.000.000
-
Small
Intestine
Birds not depleted.
Total weights at six weeks shown.
Wt! (3)
Grams
358.0
376.0
485.3
451.0
Table VTII - Continued
Page 4
Diet
Group
Sample
Most probable number per gram
Coliforms
Enterococci
Aerobic
Plate Counts
Anaerobic
52451
Birds
6321
6325
6328
6331
Basal "A"
plus 3Y $
P.P. B 12
plus .002 io
penicillin(4)
Gp. 11
Duodenum
95,000,000
25,000
6,450,000
11,900,000
Small
Intestine
45,000,000
950
38,000,000
55,000,000
115.000.000
300.000
210.000.000
300.000.000
52451
Birds
6297
6300
6305
6308
Basal "A”
3Y $> P.P.
B 12
Duodenum
4,500
2,500
195,000
1,575,000
110,000
45,000
4.500.000
450.000
20.480.000
30.870.000
950,000
2,500,000
27,090,000
31,185,000
11,000,000
2,500,000
80,955,000
64,890,000
140.000.000
15.000.000
318.150.000
1.187.550.000
52451
Birds
6334
6338
6343
6344
Small
Intestine
Gp. 9
Cecum
Basal "A"
15Y $ P.P.
B 12
Duodenum
Gp. 12
4.
5.
Cecum
Small
Intestine
Cecum
Av.
Gain (5)
Grams
127.0
114.8
4,000,000
P.P. • fermentation product, a whole dried culture of Streptomyces olivace3es.
Gain at four weeJss.
128.9
Table VIII - Continued
Page 5
Group
Diet
Sample
Aerobic
Plate Counts
Anaerobic
250,000
450,000
4,000,000
990,000
95,000
9,500,000
29,900,000
29,900,000
30.000.000
25.000.000
1.435.000.000
1.580.000.000
Duodenum
4,500
250,000
724,000
596,000
Small
Intestine
4,500
2,500,000
27,000,000
74,000,000
Cecum
95.000.000
2.500.000
172.000.000
404.000.000
Basal plus
vitamin mix
plus B 12
(3Y $) peni
cillin .002$
Gp. 3
Duodenum
25,000,000
2,500
14,650,000
32,100,000
700,000
9,500
1,850,000
3,500,000
660.000.000
25.000
970.000.000
1.230.000.000
Basal plus
vitamin m i x
plus F.P.
plus 3Y $
B 12 & Peni
cillin .002$
Gp. 7
Duodenum
450,000
9,500
667,000
1,200,000
Small
Intestine
950,000
150,000
1,540,000
2,550,000
250,000,000
250,000
525,000,000
1,640,000,000
6E151
Birds
6403
6406
6408
6412
Basal plus
vitamin mix
Gp. 1
Cecum
62551
Birds
6418
6421
64—
64—
Basal plus
vitamin m ix
plus B 12
(3Y $)
Gp. 2
62251
Birds
6425
6428
6429
6431
62251
Birds
6473
6474
6479
6483
6.
Most probable number per gram
Coliforms
Enterococci
Duodenum
Small
Intestine
Small
Intestine
Cecum
Cecum
Gain at four weeks.
Av.
Wt.
Gain (6)
Grams
99.5
123.5
132.5
131.3
Table VIII - Continued
Page 6
Group
Sample
Diet
Most probable number per gram
Conforms
Entero cocci
Aerobic
Plate Counts
Anaerobic
70951
Birds
6896
6898
6899
6900
Basal plus
3Y $ B 12
plus .00255
Penicillin
G (7)
Gp. 5
Duodenum.
1.500.000
4.500
3,252,000
2,000,000
Small
Intestine
1.500.000
7.500
22,900,000
28,900,000
95.000.000
450.000
175.000.000
250.000.000
71051
Birds
6944
6945
6946
6948
Basal (7)
plus 3Y %
B 12 in P.P.
content
Duodenum
1,500
25,000
322,000
349,000
25,000
1,500,000
740,000
625,000
Gp. 9
Cecum
250.000.000
4.500.000
640.000.000
545.000.000
71051
Birds
6915
69 7 6
6983
6986
Basal (7)
plus 3Y fo
B 12 in P.P.
.002$ Peni
cillin G
Gp. 12
9,500
950
103,500
124,000
450,000
2,500
3,020,000
5,190,000
1.100.000.000
15.000
410.000.000
690,000.000
7.
8.
......
Cecum
Sinall
Intestine
Duodenum
Small
Intestine
Cecum
Basal "A" contained vitamin mix.
Birds depleted two weeks then fed two weeks on diet indicated.
Av.
Wt. Gain
Grama (8)
144,0
128.8
130.9
Table VIII - Continued
Page 7
Group
Diet
Sample
80251
Birds
7038
7202
7232
7238
Basal (9)
plus 3Y £
vitamin
B 12
Small
Intestine
Gp. 1
Cecum
80251
Birds
7030
7051
7230
L.B.
Basal(9)
plus 3Y fo
Vitamin
B 12 plus
.002fo Peni
cillin
Gp. 2 .......
Duodenum
80351
Birds
7031
7034
7102
7221
Basal (9)
plus 10Y $
Indolacetic
Acid plus
3Y % B 12
Gp. 3
80351
Birds
7090
7091
7099
7101
Basal (9)
plus 1 0 Y #
ethyl ester
of Indolace
tic Acid plus
3Y $ B 12
Gp . 4
9.
10.
Most probable number per gram
Coliforms
Enterococci
Plate Counts
Anaerobic
40,000
4,000
1,045,000
1,980,000
450,000
2,500,000
85,000,000
100,800,000
25.000.000
25.000.000
179.000.000
780.000.000
450,000
45,000
650,000
1,480,000
7,500,000
2,500,000
38,430,000
48,510,000
45.000.000
950.000
15.000.000
570.000.000
4,500,000
4,500,000
19,600,000
21,300,000
140,000,000 '
17,200,000
114,030,000
Duodenum
Small
Intestine
Cecum
Aerobic
Duodenum
Small
Intestine
140,000,000
Cecum
450.000.000
20.000.000
400.000.000
6.340.000.000
11,000,000
14,000,000
20,000,000
23,600,000
150,000
950,000
88,200,000
168,840,000
250.000.000
250.000
640.000.000
970.000.000
Duodenum
Small
Intestine
Cecum
Basal diet "A” plus vitamin mix.
Birds depleted two weeks, then fed diet indicated two weeks.
Av.
Wt. Gain
Grams (10)
142.0
124.2
143.0
139.8
Table VIII - Continued
Page 8
Group
Diet
Sample
80451
Birds
7017
7106
7107
7086
Basal (9)
plus 40 ppm
crude olivacein plus
3Y £ B 12
Gp. 5
Duodenum
80451
Birds
7024
7053
7071
7080
Basal (9)
plus 100
ppm diphe
nol indole
plus 3Y fo
B 12
Gp. 6
Duodenum
9.
10.
Small
Intestine
Cecum
Small
Intestine
Cecum
Most probable number per gram
Coliforms
Enterococci
Aerobic
Plate Counts
Anaerobic
14,000,000
250,000
14,200,000
15,800,000
4,500,000
45,000,000
29,900,000
32,400,000
450.000.000
95.000.000
510.000.000
670.000.000
350,000
2,500,000
3,200,000
2,950,000
25,000
25,000,000
23,800,000
32,200,000
25.000.000
9.500.000
106.500.000
204.000.000
Basal diet "A" plus vitamin mix.
Birds fed depletion diet two weeks,then fed indicated diet two weeks.
Av. Wt.
Gain (10)
Grams
137.8
122.3
Table VIII - Continued
Page 9
Group
102951
Birds
8008
8014
8026
8066
103051
Birds
8003
8004
8009
8011
103151
Birds
8002
8005
8013
8047
11.
Diet
Basal rtC»
Sample
Duodenum
Small
Intestine
Most probable number per gram
Colifoims
Enterococci
Aerobic
Plate Counts
Anaerobic
740,000
250.000
66,500,000
82,220,000
1,180,000
920.000
210,000,000
239,000,000
22.000.000
9.200.000
1.420.000.000
Gp. 1
Cecum
Basal "C"
plus Peni
ciUin
10 mg 1 lb.
Duodenum
20
430
110,000
190,000
Small
Intestine
73
7,400
6,000,000
11,800,000
Gp. 2
Cecum
9.000.000
147.000
19.000.000
3,500.000.000
250,000
2,500
375,000
295,000
250,000
250,000
6,200,000
1,750,000
118,000,000
43,000,000
111,000,000
3,960,000.000
Basal "C" 0.1$ Duodenum
plus Ethomid
C/15 (Armour) Small
Intestine
Gp. 3
Cecum
Birds depleted one week, then fed three weeks on diet indicated.
Weights are total, not gain.
Av.
Wt.
(11)
180.7
228.9
194.0
Table VIII - Continued
Page 10
Group
Sample
Diet
564,000
912,000
9,200
430
255,000
1,125,000
9.200.000
3.900
31.500.000
1.135.000.000
91
92,000
4,130,000
3,460,000
240
24,000
4,900,000
51,700,000
25.000.000
9.200.000
200.000.000
220.000.000
Duodenum
24
43,000
435,000
205,400
Efcnall
Intestine
24
2.500.000
6,268,000
7,600,000
25.000.000
2.200.000
77.000.000
74.500.000
240
25,000
3,110,000
1,270,000
2,500
4,300
5,350,000
34,600,000
140.000.000
430.000
704.000.000
3.740.000.000
Duodenum
111251
Birds
8389
8442
8758
8832
Basal (12)
plus 3 Y #
Crystal
B 12
Duodenum
Gp. 2
Cecum
111251
Birds
8256
8354
8404
8483
Basal (12)
plus 3Y %
P.P. B 12
111351
Birds
8203
8403
8496
8861
Basal (12)
plus 15Y %
Crystal
B 12
Small
Intestine
S E i .6 ......
Cecum
12.
13.
Plate Counts
Anaerobic
240
Basal (12)
3Y % B 12
(Crystal
.002$ Peni
cillin
Gp. 1
.....
Aerobic
740
110951
Birds
8215
8412
8435
8620
Gp. 8
Most probable number per gram
Colifoims
Enterococci
Small
Intestine
Cecum
Small
Intestine
Cecum
Duodenum
Basal "A” feed with, vitamin mix.
Birds depleted two weeks, then fed indicated diet two weeks.
Av.
Gain (13)
Grams
137.8
132.9
128.6
124.0
Table VIII - Continued
Page 11
Group
Diet
Sample
111351
Birds
8310
8319
8693
8829
Basal (12)
plus 3T $ F.F.
B 12 plus
.002$ Peni
cillin
Gp. 7
Duodenum
111351
Birds
8216
8321
8650
8819
Basal (12)
plus 15Y %
P.P. B 12
Duodenum
12.
13.
Gp. 12
Small
Intestine
Cecun
Small
Intestine
Cecum
Most probable number per gram
Colifonns
Enterococci
Aerobic
Plate Counts
Anaerobic
36
9,200
189,000
7,310,000
430
2,500
283,500
5,103,000
45.000.000
25.000
21.500.000
2.813.000.000
9,200
2,500
2,561,000
1,745,000
240
2,500
55,000
9,450,000
920.000
2.500.000
37.500.000
5.720.000.000
Basal ”A" feed with vitamin mix.
Gain at four weeks. Birds depleted two weeks, then fed indicated diet two weeks.
Av. Wt.
Gain (13)
Grams
130.4
124.8
TABLE IZ - EFFECT OF PENICILLIN ON BACTERIAL FLORA.
Log. Averages of Numbers Per Gram (wet) Pooled Samples
Diet
No. of
Birds
Enterococoi
Colifonns
Aerobes
Anaerobes
DUODENA.
Basal A,D,C
Same / Pen.
12
12
8,017
1,683
403,600
3,500
3.515.000
1,161,500
2.183.000
535,800
Basal / B 12
Same / Pen.
48
48
10,260
147,200
33,110
7,763
1.175.000
1.067.000
1.429.000
1.910.000
SMALL INTESTINES
Basal A,D,C
Same
Pen-
12
12
51,530
165,200
1,770,000
152,400
19.900.000
26.300.000
232,300,000
97,950,000
Basal / B 12
Same / Pen.
48
48
7,430
291,100
185,800
2,723
3.565.000
1.968.000
8.974.000
3.243.000
CECA
Basal A,D,C
Same / Pen.
12
12
106,650,000
59.710.000
32,660,000
151,400
1,750,000,000
150.650.000
4,325,000,000
1,132,500,000
Basal / B 12
Same / Pen.
48
48
26.730.000
54.700.000
5,662,000
66,830
153.100.000
90,160,000
68,702,000
683,900,000
TABLE X - RELATION OF BACTERIAL NUMBERS TO CHECK GROWTH RATE
Log. Averages of Numbers (wet) Pooled Samples
Weight*
Class
No. of
Birds
No. of
Samples
Coliforms
Enterococoi
Aerobes
Anaerobes
U1 if- M M H
DUODENA
48
40
20
24
20
12
10
5
6
5
209,400
27,420
29,510
9,890
10,940
37,900
56,890
14,000
10,300
150,700
3,048,000
1,938,000
1,315,000
516,400
1,600,000
2,917,000
3,564,500
1,503,000
763,000
1,614,000
183,200
127,400
12,160
82,410
712,900
9,931,000
5,875,000
641,200
6,339,000
13,430,000
17,700,000
18,493,000
1,014,000
19,187,000
114,300,000
UI^WMH
3IALL INTESTINE
48
40
20
24
20
12
10
5
6
5
388,200
41,700
9,480
54,570
65,460
U1 it* W » H
CEGA
48
12
142,560,000
849,500
314,100,000
837,500,000
40
10
67,325,000
1,778,000
109,140,000
626,600,000
20
5
18,880,000
642,700
59,020,000
195,000,000
24
6
21,630,000
5,003,000
203,200,000
3,221,000,000
20____________5____________ 150.000.000______ 57.325.000_________ 920.450.000_______ 5.861.000.000
* Weight classes:
1 = over 130 g, 2 «= 120-130 g, 3 = 110-120 g, 4 = 100-110 g,
5 - under 100 g at four weeks.
TABLE XI - WATER IN CHECK INTESTINE CONTENTS
Basal Groups or Basal Plus Vitamin B 12
Date
Bird Nos.
Duodenum
Small
___________ Intestine
62151
6403,6406
6408.6421
84.439
87.900
80.315
Basal plus
vitamin mix
62551
6418.6421
83,787
81.400
79.789
Basal plus
3Y % B 12
71051
6944,6945
6946,6948
82.166
85.981
79.809
Basal plus
3Y $ P.P.
B 12
80251
7038,7202
7232,7238
83.848
84.521
82.257
Basal, 3Y £
Cry. B 12
102951
8008,8014
8076,8066
91.433
84.082
81.105
Basal »C"
111251
8389,8442
8758,8832
82.264
84.202
80.721
Basal "A" plus
3Y fo B 12
111351
8256,8354
8404,8483
83.290
85.005
83.532
Basal "A" plus
3Y
P.P. B 12
111351
8203,8403
8496,8861
85.154
86.355
82.325
Basal «A" plus
15Y f, B 12
11751
4446,4449
4452 - (3)
82.584
86.957
77.297
Basal
11951
4490,4493
4499 - (3)
81.158
84.652
82.172
Basal plus
3.2Y % B 12
13051
4614,4616
4622,4623
94.691
82.199
78.835
Basal plus
0.7Y % B 12
20251
4651,4653
4654,4655
81.736
82.991
79.325
Basal plus
5.6Y % B 12
33151
5337,5348
5354,5358
78.880
82.685
80.968
Basal "B" only
52451
6297,6300
6305,6308
86.417
86.641
82.627
Basal "A" plus
3Y f, P.P. B 12
52451
6334,6338
6343.6344
87.513
85.714
79.461
Basal "A" plus
15Y