Prevalence, Serotypes, and Antimicrobial Resistance Profiles Among Isolated from Food Catering Workers in Nantong, China.

is a worldwide foodborne pathogen causing human disease. Food handlers, who are potential carriers of , may transmit the pathogen to consumers through food. To determine the prevalence of serovars among food handlers working in the catering industry in Nantong, China, a total of 214,542 food handlers' fecal samples were tested for in the Nantong CDC (Centers for Disease Control) from 2012 to 2017. Among those tested, 193 (0.09%) were identified to be positive for , and the highest detection rate was 0.16% during the period of July to September. Serotyping analysis showed that serovar Typhimurium was the predominant serotype (16.1%), followed by Derby (13.5%), Enteritidis (11.4%), and London (11.4%). The high detection rate of Derby was probably closely related to its high prevalence of the serotype in pork, which is the primary meat consumed by the Chinese. Antibiotic susceptibility analysis demonstrated that 73.4% of the isolates were multidrug-resistant (MDR) strains with predominant resistance to ampicillin (AMP, 64.6%), followed by resistance to sulfisoxazole (SUL, 58.1%), nalidixic acid (55.8%), and tetracycline (TET, 44.5%). Therefore, MDR strain carriage among food handlers working in the catering industry might be a potential source of human salmonellosis, especially for the predominant MDR genotype isolates (32.3%) with resistance to AMP, SUL, and TET.