2009—2020年北京市朝阳区113株食源性金黄色葡萄球菌耐甲氧西林和肠毒素/类肠毒素基因携带与分子分型分析

目的 了解北京市朝阳区2009—2020年113株食源性金黄色葡萄球菌甲氧西林耐药、肠毒素/类肠毒素基因携带和分子分型情况.方法 采用纸片扩散法进行头孢西丁药物敏感性实验,结合mecA基因扩增鉴定耐甲氧西林金黄色葡萄球菌(methicillin-resistant Staphylococcus aureus,MRSA)...

Diversity of methicillin-resistant Staphylococcus aureus and enterotoxins/ enterotoxin-likes and molecular typing of 113 strains Staphylococcus aureus from foodborne in Chaoyang district of Beijing from 2009 to 2020

Objective To investigate the methicillin-resistance, enterotoxin/enterotoxin-like gene carrier and molecular typing of 113 foodborne Staphylococcus aureus strains from 2009 to 2020 in Chaoyang District, Beijing. Methods Cefoxitin sensitivity was detected by disk diffusion method and mecA resistance gene was amplified by PCR.Twenty-eight enterotoxin/enterotoxin-like genes were detected by real-time quantitative PCR.Molecular typing is performed by pulsing field gel electrophoresis and Multilocus sequence typing. Results 7 strains of MRSA (6.19%, 7/113) were detected, including 6 strains of ST59 and 1 strain of ST9.All strains carried 1-14 kinds of enterotoxins/enterotoxins, and a total of 24 kinds of enterotoxins/enterotoxins were detected.The carrying rate of SEA-see type 5 enterotoxin was 45.13%.MLST detected 24 types, ST1, ST398, ST7, ST59 were dominant type.Five new types ST6656, ST6688, ST6709, ST6745 and ST6754 .PFGE detected 25 types, H type (11/113), I type (9/113) and J type (29/113) were the dominant types, accounting for 43.36%. Conclusion The isolation rate of food-borne STaphylococcus aureus MRSA strain was lower than that of clinical strains.PFGE results showed that dominant strains of food-borne STaphylococcus aureus were concentrated in the region.The main ST types were associated with nosocomial, community infection and animal, and five new ST types were found.There was a certain correlation between enterotoxin/enterotoxoid and ST type.St1-mssa-sea-seh-sek-seq-selw-selx was the dominant strain;Only 5 kinds of classical enterotoxins can not represent the pathogenic factors of food poisoning caused by STaphylococcus aureus, so the detection scope of enterotoxins should be expanded.