Shaojun Huang, Aojun Lu, Yusha Xu, Youying Tang, Ting Li
Salmonella enterica contamination in retail meat is a persistent threat to global food safety. Comprehensive regional data on serovar distribution and antimicrobial resistance are essential for evidence-based risk assessment and control. From June 2019 to October 2025, 711 fresh meat samples (504 pork, 207 chicken) were conveniently collected from supermarkets and farmers' markets in Yuyao, China. Salmonella isolation and identification followed the China National Food Safety Standard GB 4789.4-2016 (Food Microbiological Examination: Salmonella spp.); serotyping used the Kauffmann-White scheme; susceptibility to 17 agents was tested by Kirby-Bauer disk diffusion per CLSI M100 (2020). The overall detection rate was 50.4% (358/711), with 52.2% (263/504) in pork and 45.9% (95/207) in chicken. In total, 451 non-duplicate isolates of 30 serovars were recovered. Salmonella enterica subsp. enterica serovar Rissen (23.9%, 81/339) and serovar 4,[5],12:i:- (23.6%, 80/339) dominated in pork, while serovar Enteritidis (39.3%, 44/112) was most prevalent in chicken. Co-contamination with multiple serovars was detected in 12.1% (86/711) of samples. Resistance was highest to ampicillin (77.2%, 348/451), tetracycline (74.9%, 338/451), and trimethoprim-sulfamethoxazole (60.5%, 273/451); all isolates were susceptible to imipenem. Overall, 76.1% (343/451) of isolates were multidrug-resistant (MDR), slightly higher in pork (78.2% vs 69.6%). The ACSSuT phenotype (resistance to ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline) was detected in 14.2% (64/451) of isolates, mainly in serovar Rissen and serovar 4,[5],12:i:-, most with co-resistance to extended-spectrum cephalosporins and quinolones. Retail pork and chicken in Yuyao are highly contaminated, with high serovar diversity and severe antimicrobial resistance, underscoring the urgent need for sustained surveillance and targeted interventions.