食品科学2016，Vol.37Issue(13)：140-146,7.DOI:10.7506/spkx1002-6630-201613025
金黄色葡萄球菌新型肠毒素sek基因在3株食品分离菌株中的表达
Temporal Expression of Staphylococcal Enterotoxin K (sek) Gene in Three Isolates from Food Samples
摘要
Abstract
Objective: The newly identified staphylococcal enterotoxin sek gene is found to be very popular in clinical methicillin-resistant S. aureus isolates. The study of sek gene temporal expression would provide some valuable information and new data for food poisoning prevention and disease control linked to this bacterium. Methods:Three strains (SA005, SA008 and SAB0) with sek gene from foodborne isolates in our lab were selected by PCR detection of 21 different SEs genes. The growth curves of three strains were monitored during the growth phase in TSB. Total RNAs from three strains were extracted at different growth periods, and a quantitative real time-PCR was developed to monitor the relative expression of sek gene. Results:The results of virulence gene detection showed that SA005 harbored 16S, nuc, mecA, seb, sec, sek and sex genes, SA008 harbored 16S, nuc, mecA, sea, sek and sex genes, and SAB0 harbored 16S, nuc, sek and sex genes. The characteristics of growth curves for three strains had similarity, which exhibited a turning point around 18 h, and then entered the stationary growth phase. mRNA expression levels were shown during all the growth phases (12–120 h);however, there were very obvious differences among three strains and among different sampling points. The relative expression of sek gene was very high at 48 h and very low at 84 h for SA005. For SA008, it was very high at 24 h, very low at 48 h, and was stable between 60–120 h. The relative expression of sek gene in SAB0 presented a parabolic trend, with a high level at 60 h and 72 h (P>0.05). Conclusion:The relative expression of sek gene among three strains had a significant difference. Even in the same strain, the relative expression of sek gene was different at different time points. Strain-to-strain variations with different background genes may be the key points for different expression patterns of sek gene.关键词
金黄色葡萄球菌/新型肠毒素/sek基因/实时荧光定量聚合酶链式反应/时序性表达Key words
Staphylococcus aureus/newly identified enterotoxins/sek gene/real time-polymerase chain reaction (real time-PCR)/temporal expression分类
轻工纺织引用本文复制引用
王琼,唐俊妮,汤承,陈娟,刘骥,蔡自建..金黄色葡萄球菌新型肠毒素sek基因在3株食品分离菌株中的表达[J].食品科学,2016,37(13):140-146,7.基金项目
国家自然科学基金面上项目（31371781）；四川省应用基础研究计划项目（14JC0702）；教育部“新世纪优秀人才支持计划”项目 （）
