我国市售食用菌中金黄色葡萄球菌污染调查、耐药性及其肠毒素基因检测

摘要

调查了2011—2016年我国市售食用菌中金黄色葡萄球菌的污染情况,并对分离到的相关菌株进行了肠毒素基因的检测和耐药性分析.收集全国39个城市699份市售食用菌,利用定性和定量检测方法,检出金黄色葡萄球菌阳性样品33份,平均污染率4.72%,污染水平9.75MPN/g.24种抗生素的药敏结果显示,分离株耐药情况严重,对利奈唑胺、利福平敏感,对氨苄西林等22种抗生素都产生不同程度的耐药.7株分离株经表型和分子鉴定确定为耐甲氧西林金黄色葡萄球菌.运用聚合酶链式反应法对分离的39株金黄色葡萄球菌进行了18种肠毒素基因检测,约60%分离株携带4~6种肠毒素基因,携带率最高的肠毒素基因是sei,其次是sem、seg、seq、sec、seb、sen.本研究反映了我国市售食用菌金黄色葡萄球菌污染的潜在风险,相关分离株具毒性潜力,且耐药性严重,应引起重视.%This study investigated the contamination level of Staphylococcus aureus of retail edible mush-rooms in China. 699 retail edible mushroom samples were collected from 39 cities in China during 2011 to 2016,33 samples(4.72%) were positive for Staphylococcus aureus and the geometric mean was 9.75 MPN/g. A total of 39 isolates were analyzed.For antibiotics susceptibility tests, all isolated strains were resistant to 22 kinds of different antibiotics,such as ampicillin,and only sensitive to linezolid and rifam-picin. Seven isolates were resistant to cefoxitin and carried mecA gene,confirmed as methicililin-resistant Staphylococcus aureus (MRSA).Polymerase chain reaction(PCR) analysis of 18 SE genes showed that 4-6 kinds of enterotoxin genes carried by 60% isolated strains,and sei gene was the most frequently de-tected,followed by sem,seg,seq,sec,seb,sen.This study reflects the potential risk of Staphylococcus au-reus contamination of retail edible mushrooms in China and these isolate strains had virulence potential and drug tolerance,which should be drawn public attention.