Prevalence and antibiotic resistance characteristics of extended-spectrum beta-lactamase (ESBL)-Producing Escherichia coli Isolated from pork sold at retail markets in Hanoi

Tóm tắt

Antibiotic-resistant bacteria, particularly Extended-Spectrum β-Lactamase (ESBL)-producing Escherichia coli, have emerged as a serious threat to public health. The widespread use of antibiotics in agriculture, especially pig farming, contributes to the transmission of these resistant bacteria through the food chain. Pork, a staple food in Vietnam, represents a critical vector for this transmission. This study aimed to determine the prevalence, phenotypic antibiotic resistance profiles, and genetic characteristics (ESBL-encoding genes, phylogenetic groups, and clonal relatedness) of ESBL-producing E. coli isolated from pork sold at retail markets in Hanoi, Vietnam. A cross-sectional study was conducted to collect 70 fresh pork samples from retail markets across Hanoi. The prevalence of cefotaxime-resistant E. coli in pork samples was 88.6% (62/70). Among the 167 resistant isolates recovered, 87.4% (146/167) were confirmed as ESBL producers. These isolates exhibited high rates of multidrug resistance (MDR), with 71.2% (104/146) resistant to three or more antibiotic classes. Critically, resistance to last-resort antibiotics was detected, including colistin (10.3%) and carbapenems (2 isolates). Genotypically, blaTEM was the most prevalent gene, detected in 60.3% (88/146) of isolates, followed by blaCTX-M-9 (24.7%) and blaCTX-M-1 (22.6%). Phylogenetic analysis showed a dominance of group D (54.8%). MLVA revealed high genetic diversity, with 71.9% of strains showing no close clonal relationship. This study reveals an alarmingly high prevalence of MDR ESBL-producing E. coli circulating in retail pork in Hanoi.