Earlier studies have validated the isolation of extended-spectrum beta-lactamase-producing Salmonella (ESBL-Sal) strains from food. While poultry is recognized as a reservoir for Salmonella contamination, pertinent data regarding ESBL-Sal remains limited. Consequently, the Ministry of Food and Drug Safety has isolated Salmonella spp. from retail meat and evaluated their antibiotic susceptibility and genetic characteristics via whole-genome sequencing. To further elucidate these aspects, this study investigates the prevalence, antibiotic resistance profiles, genomic characteristics, and homology of ESBL-Sal spp. obtained from livestock-derived products in South Korean retail outlets. A total of 653 Salmonella spp. were isolated from 1,876 meat samples, including 509 beef, 503 pork, 555 chicken, and 309 duck samples. The prevalence rates of Salmonella were 0.0%, 1.1%, 22.2%, and 36.1% in the beef, pork, chicken, and duck samples, respectively. ESBL-Sal was exclusively identified in poultry meat, with a prevalence of 1.4% in the chicken samples (8/555) and 0.3% in the duck samples (1/309). All ESBL-Sal strains carried the blaCTX-M-1 gene and exhibited resistance to ampicillin, ceftiofur, ceftazidime, nalidixic acid, and tetracycline. Eight ESBL-Sal isolates were identified as S. Enteritidis with sequence type (ST) 11. The major plasmid replicons of the Enteritidis-ST11 strains were IncFIB(S) and IncFII(S), carrying antimicrobial resistance genes (β-lactam, tetracycline, and aminoglycoside) and 166 virulence factor genes. The results of this study provide valuable insights for the surveillance and monitoring of ESBL-Sal in South Korean food chain.

中文翻译：

---

从韩国零售肉类中分离出的产广谱 β-内酰胺酶沙门氏菌的遗传特征。

早期的研究已经验证了从食品中分离产生超广谱 β-内酰胺酶的沙门氏菌(ESBL-Sal) 菌株。虽然家禽被认为是沙门氏菌污染的储存库，但有关 ESBL-Sal 的相关数据仍然有限。因此，食品药品安全部已分离出沙门氏菌。从零售肉类中提取，并通过全基因组测序评估其抗生素敏感性和遗传特征。为了进一步阐明这些方面，本研究调查了 ESBL-Sal spp 的患病率、抗生素耐药性概况、基因组特征和同源性。从韩国零售店的牲畜衍生产品中获得。共有 653 种沙门氏菌。从 1,876 个肉类样本中分离出 509 个牛肉样本、503 个猪肉样本、555 个鸡肉样本和 309 个鸭样本。牛肉、猪肉、鸡肉和鸭样品中沙门氏菌检出率分别为0.0%、1.1%、22.2%和36.1%。 ESBL-Sal 只在禽肉中被发现，在鸡肉样品中的患病率为 1.4% (8/555)，在鸭样品中的患病率为 0.3% (1/309)。所有ESBL-Sal菌株均携带bla CTX-M-1基因，并对氨苄西林、头孢噻呋、头孢他啶、萘啶酸和四环素表现出耐药性。 8株ESBL-Sal分离株被鉴定为序列类型（ST）11的肠炎沙门氏菌。肠炎沙门氏菌-ST11菌株的主要质粒复制子是IncFIB（S）和IncFII（S），携带抗菌药物耐药基因（β-内酰胺，四环素） 、氨基糖苷类）和 166 个毒力因子基因。这项研究的结果为韩国食物链中 ESBL-Sal 的监测提供了宝贵的见解。