A food poisoning caused by ST7 Staphylococcal aureus harboring sea gene in Hainan province, China

Yahui Guo; Xiaojie Yu; Jixiao Wang; De Hua; Yuanhai You; Qingbo Wu; Qinglong Ji; Jianzhong Zhang; Liefei Li; Yuan Hu; Zhonghui Wu; Xiaoyue Wei; Lianqun Jin; Fanliang Meng; Yuhua Yang; Xiaofeng Hu; Lijin Long; Songnian Hu; Heyuan Qi; Juncai Ma; Wenwen Bei; Xiaomei Yan; Haibin Wang; Zilong He

doi:10.3389/fmicb.2023.1110720

A food poisoning caused by ST7 Staphylococcal aureus harboring sea gene in Hainan province, China

Front Microbiol. 2023 Mar 16:14:1110720. doi: 10.3389/fmicb.2023.1110720. eCollection 2023.

Authors

Yahui Guo^{1

2

3}, Xiaojie Yu⁴, Jixiao Wang⁴, De Hua⁴, Yuanhai You², Qingbo Wu⁴, Qinglong Ji⁵, Jianzhong Zhang², Liefei Li⁴, Yuan Hu², Zhonghui Wu⁴, Xiaoyue Wei², Lianqun Jin⁶, Fanliang Meng², Yuhua Yang², Xiaofeng Hu⁶, Lijin Long², Songnian Hu⁷, Heyuan Qi⁸, Juncai Ma^{7

8}, Wenwen Bei⁴, Xiaomei Yan², Haibin Wang^{1

3}, Zilong He⁹

Affiliations

¹ Baotou Medical College, Inner Mongolia University of Science and Technology, Baotou, China.
² Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China.
³ Beijing Chaoyang District Center for Disease Control and Prevention, Beijing, China.
⁴ Hainan Provincial Center for Disease Control and Prevention, Haikou, China.
⁵ Chinese Academy of Inspection and Quarantine, Beijing, China.
⁶ Chinese PLA Center for Disease Control and Prevention, Beijing, China.
⁷ State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
⁸ Microbial Resource and Big Data Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
⁹ Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Interdisciplinary Innovation Institute of Medicine and Engineering, School of Engineering Medicine, Beihang University, Beijing, China.

Abstract

ST7 Staphylococcus aureus is highly prevalent in humans, pigs, as well as food in China; however, staphylococcal food poisoning (SFP) caused by this ST type has rarely been reported. On May 13, 2017, an SFP outbreak caused by ST7 S. aureus strains occurred in two campuses of a kindergarten in Hainan Province, China. We investigated the genomic characteristics and phylogenetic analysis of ST7 SFP strains combined with the 91 ST7 food-borne strains from 12 provinces in China by performing whole-genome sequencing (WGS). There was clear phylogenetic clustering of seven SFP isolates. Six antibiotic genes including blaZ, ANT (4')-Ib, tetK, lnuA, norA, and lmrS were present in all SFP strains and also showed a higher prevalence rate in 91 food-borne strains. A multiple resistance plasmid pDC53285 was present in SFP strain DC53285. Among 27 enterotoxin genes, only sea and selx were found in all SFP strains. A ФSa3int prophage containing type A immune evasion cluster (sea, scn, sak, and chp) was identified in SFP strain. In conclusion, we concluded that this SFP event was caused by the contamination of cakes with ST7 S. aureus. This study indicated the potential risk of new emergencing ST7 clone for SFP.

Keywords: enterotoxin A; plasmids; prophage; sequence type 7; staphylococcus food poisoning; whole-genome sequencing.