"The over-prescription and misuse of antibiotics has led some bacterial strains to become resistant to one, multiple, or all currently available antibiotics. In order to treat an antibiotic resistant bacterial infection, a novel antibiotic or therapeutic is required. Up until the last few years, there had been a trend of fewer new antibiotics due to pharmaceutical companies not pursuing antibiotic development. The continuous threat of antibiotic resistance and the lack of antibiotic research led to the National Action Plan, which called for novel, rapid diagnostic tools and new therapeutics to combat antibiotic resistance. The main reason for the lack of interest in antibiotic development is that drug development now cost a pharmaceutical greater than $2.5 billion and can take over 10 years. In addition, only 10.4% of drugs that enter clinical trials eventually are approved. One of the main causes of this low success rate is that the drugs do not have the same pharmacokinetics (PK) or pharmacodynamics (PD) as the drugs did in in vitro and in vivo animal models. These differences in PK/PD can lead to safety and efficacy concerns in humans. In this dissertation, this issue is combated with new technologies for antibiotic resistance identification. A rapid, static susceptibility assay was created in order monitor the growth of a bacterial culture by measuring the extracellular ATP/OD600, which in a healthy culture should increase to a maximum during early logarithmic growth phase and then decrease. Adding an antibiotic to a growing culture after this ATP/OD600 maximum led to an increase in the ATP/OD600, while a healthy culture decreased leading a statistical difference (alpha = 0.05) in 20--60 minutes after adding the antibiotic. This increase in the ATP/OD600 was due to the antibiotic's ability to effectively kill the bacteria by lysing leading to the OD600 remaining stable and extracellular ATP levels to increase. This trend was not seen when an antibiotic that the bacteria were resistant to was added. This procedure could also determine which antibiotic is killing the most bacteria in a mixed bacterial culture. The above procedure was adapted to be dynamic in order to expose the bacteria to a PK curve similar to that seen in a human so more clinically-relevant PD data could be measured. This was achieved by creating a fluidic, two compartment model that was 3D printed, which utilized porous membrane inserts that were created by novel 3D printed procedures to incorporate the membranes into the 3D printing structure. The device was characterized using fluorescein (332.31 g/mol) due to having similar properties to the antibiotic, levofloxacin (361.37 g/mol). The devices were impervious to leaking and were successful in replicating PK curves for an oral, intermittent intravenous (IV), and continuous IV administration. Replacing the fluorescein solution with a levofloxacin solution in growth media, bacteria were able to be exposed to an oral levofloxacin PK curve (C max = 12.4 +/- 3.0 microM; tmax = 1 hour; half-life = 5.2 +/- 0.5 hours). A kanamycin-resistant strain of Escherichia coli was determined to have a statistical difference in the ATP/OD600 when exposed to a levofloxacin concentration of 3.5 +/- 1.3 microM in the secondary compartment while a chloramphenicol-resistant strain of Bacillus subtilis showed a statistical difference at a concentration of 4.8 +/- 1.8 microM."--Pages ii-iii.
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