The distribution and dynamics of resistance genes in soil microbiomes

"The soil microbiome harbors immense microbial biodiversity that encodes important functions of interest to public health. These include functional genes that encode resistance to antibiotics and arsenic. In the case of antibiotic resistance, transfer from environmental strains to pathogens is a public health risk, and arsenic resistance and metabolisms are important for bioremediation as they impact the fate of arsenic in the environment. While these resistance genes are well-characterized in vitro, the full scope of their environmental distribution, diversity, and interspecies transfer is unknown. A better understanding of the diversity and distribution of resistance genes would provide insights into the potential for mitigation of public health problems such as arsenic contamination and antibiotic resistance. The work in this dissertation used a combination of cultivation-dependent and -independent techniques to better understand the dynamics and distributions of antibiotic and arsenic resistance genes in the environment. The influence of a disturbance on microbial antibiotic resistance and arsenic related genes was investigated by examining soils overlaying an underground coal mine fire in Centralia, PA. Additionally, soil meta-analyses were used to determine broader distributions patterns of these genes. These data and methods not only provide insights into the distributions and dynamics of antibiotic resistance and arsenic related genes in soil microbiomes but also provide a framework for future studies of other functional genes."--Page ii.