Investigation into the prevalence of enterotoxin genes and genetic background of Staphylococcus aureus isolates from retain foods in Hangzhou, China

BMC Microbiology

Research

Gang Zhao¹  Fuhong Chen²  Yan Qi²  Wei Yang²  Qi Chen²  Zhengqing Lou² 

[1] Hangzhou Center for Disease Control and Prevention, 310021, Hangzhou, China;Hangzhou Traditional Chinese Medicine Hospital Affiliated to Zhejiang Chinese Medical University, 310000, Hangzhou, China;

关键词: Staphylococcus aureus;    Staphylococcal enterotoxins;    Gene cluster;    Clonal complexes;    spa;   

DOI  :  10.1186/s12866-023-03027-0

 received in 2023-07-28, accepted in 2023-09-20,  发布年份 2023

来源: Springer

【 摘 要 】

BackgroundStaphylococcus aureus expresses numerous toxins, many of which are strongly believed to be responsible for specific symptoms and even diseases, making it significant in the pathogenesis of human health. Enterotoxins, which are vital toxins, are associated with foodborne illnesses that manifest through symptoms like vomiting and diarrhea. In the present study, 264 S. aureus isolates obtained from various retail foods in Hangzhou, China were further investigated the profiles of enterotoxin genes and genetic backgrounds.ResultsApproximately, 64.02% of the isolates from diverse sources contained at least one Staphylococcal Enterotoxin (SE) genes, displaying a total of 36 distinct combinations. Enterotoxin gene cluster (egc) encoded enterotoxin genes, normally designated by seg, sei, sem, sen, seo and selu, plus with sep were more frequently detected (33.73%, each). In contrast, see, ses and set were absent in any of the isolates tested. A total of 44 sequence types (STs), 20 clonal complexes (CCs) and 66 different staphylococcal protein A (spa) types (including six novel types) were identified among those 169 SE-positive isolates. Moreover, nineteen methicillin-resistant Staphylococcus aureus (MRSA) isolates were identified. The majority of those isolates belonged to the CC59-Sccmec IVa cluster and carried the seb-sek-seq gene cluster. The egc cluster, either coexisting with or without other enterotoxin genes, was observed in all isolates allocated into CC5, CC9, CC20, CC25, CC72 and ST672. Irrespective of the spa types and origins of the food, it appeared that seh was a distinct genetic element present in isolates belonging to the CC1 clonal lineage.ConclusionsThe results not only proposed a suspected relationship between distribution of enterotoxigenic strains and genetic backgrounds, but also attributed the presence of novel enterotoxins to potential hazards in food safety.

【 授权许可】

CC BY   
© BioMed Central Ltd., part of Springer Nature 2023

【 图 表 】

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