Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/31/2016
Publication Date: N/A
Technical Abstract: The use of antibiotics in animal production has been highlighted as a key contributor to the increasing prevalence of antibiotic resistance in agroecosystems. Gram negative bacteria, such as the Enterobacteriaceae, are important facilitators for resistance gene dissemination in the environment and into human pathogens because they harbor multi-drug resistant plasmids. Previous studies in our lab and others have shown that certain antibiotic treatments increase the abundance of Enterobacteriaceae populations in mammalian gut microbiomes. Here we analyzed fecal plasmidomes from antibiotic-treated swine to define the potential for transmission of swine-derived resistance genes to the environment and the food chain, which will contribute to informing the risk of pathogens acquiring new resistances. We compared two fecal plasmid extraction methods to evaluate detection limits and plasmid diversity with and without multiple displacement amplification. For both of the extraction methods, replication proteins corresponding with plasmids found in the Enterobacteriaceae were only detected after multiple displacement amplification. Preliminary analyses indicated that the resistance gene diversity was also increased after amplification, highlighting the importance of selecting for low abundance plasmids. Continued analyses of the plasmidomes from treated and untreated swine will determine whether antibiotic administration influences the abundance and diversity of multi-drug resistant plasmids in the swine fecal microbiota. Plasmidome analysis is therefore a useful tool for specifically evaluating the potential for mobility of resistance genes among bacteria in agroecosystems and the food chain.