Characteristics of Shiga Toxin-Producing <i>Escherichia coli</i> Circulating in Asymptomatic Food Handlers
Xinxia Sui,
Xi Yang,
Ming Luo,
Hua Wang,
Qian Liu,
Hui Sun,
Yujuan Jin,
Yannong Wu,
Xiangning Bai,
Yanwen Xiong
Affiliations
Xinxia Sui
National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
Xi Yang
National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
Ming Luo
Yulin Center for Disease Control and Prevention, Yulin 537000, China
Hua Wang
National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
Qian Liu
National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
Hui Sun
National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
Yujuan Jin
Longgang Center for Disease Control and Prevention, Shenzhen 518172, China
Yannong Wu
Yulin Center for Disease Control and Prevention, Yulin 537000, China
Xiangning Bai
National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
Yanwen Xiong
National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
Shiga toxin-producing Escherichia coli (STEC) is a foodborne zoonotic pathogen that causes diarrhea, hemorrhagic colitis (HC), and hemolytic uremic syndrome (HUS) worldwide. Since the infection can be asymptomatic, the circulation of STEC in some asymptomatic carriers, especially in healthy-food-related professionals, is not yet well understood. In this study, a total of 3987 anal swab samples from asymptomatic food handlers were collected, and ten swabs recovered STEC strains (0.251%). Of the ten STEC isolates, seven serotypes and eight sequence types (ST) were determined using whole genome sequencing (WGS). Two stx1 subtypes (stx1a and stx1c) and four stx2 subtypes (stx2a, stx2b, stx2d, and stx2e) were detected. Seven different insertion sites were found in fourteen Stx prophages, and the dmsB and yfhL were the newly identified insertion sites. The ten strains showed the variable Stx transcription levels after the mitomycin C induction. The whole-genome phylogeny indicated that the strains from the asymptomatic food handlers were genetically distant from the strains of HUS patients. The STEC isolates circulating in asymptomatic carriers might pose a low potential to cause disease.
