• Korean Journal of Microbiology
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• v.50 no.2
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• pp.114-118
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• 2014

A total of 122 ESBL-producing intestinal bacteria were collected from regional hospitals in the Chungcheong area. Combination disk test (CDT) was performed for antimaicrobial susceptability using cefotaxime and cefotaxime/clavulanate according to Clinical Laboratory Standard Institute (CLSI). Mutiplex PCR using specific primers was performed for a detection of ESBL-genotypes and enterobacterial repetitive intergenic consensus (ERIC)-PCR was carried out for the tracking of molecular epidemiology. In the confirmation test using CDT, 73 out of 76 (96.1%) ESBL-producing Escherichia coli and 43 out of 46 (93.4%) ESBL-producing Klebsiella pnemoniae were positive. In the multiplex PCR, 60.5% of E. coil were positive for CTX-M-2 type gene and 56.5% of K. pneumoniae were positive for VEB -1 type gene. In the ERIC-PCR, E. coil isolates formed 5 clusters and K. pneumoniae isolates were grouped into 4 clusters depending on region. Genotypes of clinical isolates are useful for detection and differentiation of ESBL producing intestinal bacteria. The ERIC-PCR method is thought to be helpful for establishing a regional surveillance system for infection due to its formation of different clusters depending on region.

• Korean Journal of Environmental Agriculture
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• v.41 no.4
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• pp.335-343
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• 2022

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 feces/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 aminoglycoside resistance (aac(6')-Ib), beta-lactam resistance (bla_TEM, bla_CTX-M), macrolide resistance (ermC), a class 1 integronsintegrase 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, followed 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 patterns in human and livestock fecal samples were identified. The abundance of ARGs and integron genes detected in the samples were associated with the amount of antibiotics commonly used for human and livestocks. We found diverse microbial communities associated with antibiotics resistance genes in different hosts, suggesting that antibiotics resistance can disseminate across environments through various routes. Identifying the routes of ARG dissemination in the environment would be the first step to overcome the challenge of antibiotic resistance in the future.