Co-occurrence Analyses of Antibiotic Resistance Genes and Microbial Community in Human and Livestock Animal Feces

BACKGROUND: Antibiotics used in animal husbandry for disease prevention and treatment have resulted in the rapid progression of antibiotic resistant bacteria which can be introduced into the environment through livestock fe-ces/manure, disseminating antibiotic resistant genes (ARGs). In this study, fecal samples were collected from the livestock farms located in Jeju Island to investigate the relationship between microbial communities and ARGs. METHODS AND RESULTS: Illumina MiSeq sequencing was applied to characterize microbial communities within each fecal sample. Using quantitative PCR (qPCR), ten ARGs encoding tetracycline resistance ( tetB , tetM ), sulfonamide resistance ( sul1 , sul2 ), fluoroquinolone resistance ( qnrD , qnrS ), fluoroquinolone and aminoglyco-side resistance ( aac(6')-Ib ), beta-lactam resistance ( bla TEM , bla CTX-M ), macrolide resistance ( ermC ), a class 1 integrons-integrase gene ( intI1 ), and a class 2 integrons-integrase gene ( intI2 ) were quantified. The results showed that Firmicutes and Bacteroidetes were dominant in human, cow, horse, and pig groups, while Firmicutes and Actinobacteria were dominant in chicken group. Among ARGs, tetM was detected with the highest number of copies, fol-lowed by sul1 and sul2 . Most of the genera belonging to Firmicutes showed positive correlations with ARGs and integron genes. There were 97, 34, 31, 25, and 22 genera in chicken, cow, pig, human, and horse respectively which showed positive correlations with ARGs and integron genes. In network analysis, we identified diversity of microbial communities which correlated with ARGs and integron genes. CONCLUSION(S): In this study, antibiotic resistance pat-terns in human and livestock fecal samples were identified.