부산대학교 도서관

Salmonellacauses foodborne disease outbreaks worldwide and raises concerns about public health and economic losses. To determine prevalence, serovar, antimicrobial resistance patterns, and the presence of extended-spectrum β-lactamase (ESBL) genes in a cross-sectional study, 418 total samples from feces and carcasses (from three slaughterhouses) and pork and cutting boards (from four markets) were collected in a central Thailand province in 2017 and 2018. Of the 418 samples, 272 (65.1%) were positive for Salmonella. The prevalence of Salmonella-positive samples from markets (158 of 178; 88.8%) was significantly higher than that among samples from slaughterhouses (114 of 240; 47.5%) (P< 0.05). A total of 1,030 isolates were identified; 409 were assigned to 45 serovars, with SalmonellaRissen the most common (82 of 409; 20%). Two serovars, SalmonellaCannstatt and SalmonellaBraubach, were identified for the first time in Thailand in market and slaughterhouse samples, respectively. Among 180 isolates representing 19 serovars, 133 (73.9%) exhibited multidrug resistance. Screening for ESBL production revealed that 41 (10.3%) of 399 isolates were ESBL positive. The prevalence of ESBL-producing Salmonellaisolates was significantly higher among the market isolates (31 of 41; 75.6%) than among the slaughterhouse isolates in (10 of 41; 24.4%) (P< 0.05). In market samples, 24 (77.4%) of 31 isolates were recovered from pork and 7 (22.6%) were recovered from cutting boards. Nine ESBL-producing isolates carried single ESBL genes, either blaTEM(4 of 41 isolates; 9.8%) or blaCTX-M(5 of 41 isolates; 12.2%), whereas 11 (26.8%) carried both blaTEMand blaCTX-M. No ESBL-producing Salmonellaisolate carried the blaSHVgene. These results suggest that pigs, their flesh, and cutting boards used for processing pork could be reservoirs for widespread ESBL-producing Salmonellaisolates with multidrug resistance and outbreak potential across the food chain.