摘要
Antibiotics used for agricultural purpose has contributed to the increased prevalence of antibiotic-resistant bacteria. The goal of this study was to investigate the prevalence and antimicrobial resistance of ESBL-producing E. coli in small-scaled poultry farms and retail chicken. The cultured E. coli isolates were subjected to phenotypic tests, susceptibility tests, and the polymerase chain reaction for detection of blacTX-M, blasHv, and blaTEM genes. From 120 samples each of chicken feces, retail chicken, soil and chicken feed, ESBL-producing E. coli isolates were detected in 75.9%, 63.6%, 39.2%, and 13.3% of the samples, respectively. Minimum inhibitory concentration （MICs） values indicated that ESBL-producing E. coli were resistance to ampicillin （MIC 〉 32 μg/mL）, gentamicin （M1C ≥ 16 μg/mL）, cefotaxime （MIC 〉 4 μg/mL） and cefhiaxone （MIC 〉 4 gg/mL）, respectively. The total resistance for imipenem was also observed at 1.0% （MIC ≥ 4 gg/mL） and none of the isolates were resistant to ceftazidime （MIC 〉 16 μg/mL）. ESBL-producing E. coli from chicken feces and retail chicken carried blasHv gene at a rate of 6.8% and 5.7%, respectively and blaCTX-M gene was also revealed at 2.9% in retail chicken. Moreover, ESBL-producing E. coli isolated from soil harbored blasnv and blaCTX-M genes at 5%. None of the feed samples yielded ESBLs genes. Twenty three resistance patterns were observed for multi-resistant ESBL-producing E. coli. This study highlights the prevalence of multi-antimicrobial resistant ESBL-producing E. coli in small-scaledpoultry farms and retail chicken, hence the need to review poultry management practices to minimize the occurrence.
