肠出血性大肠杆菌O26∶H11鞭毛抗原的诱导及鉴定研究

Induction and identification of flagellum antigen of EHEC O26∶H11

目的对肠出血性大肠杆菌(EHEC)O26∶H11鞭毛抗原诱导及鉴定进行研究,为日常检测提供可借鉴的方法。方法对疑似EHEC O26∶H11菌株进行生化鉴定和血清分型,比较37℃及28℃2种温度Swarm琼脂诱导鞭毛抗原的效果,并采用荧光定量PCR检测8种致泻性大肠杆菌毒力基因eae、stx1、stx2、lt、st、bfp A、aggR和ipa H。结果 28℃诱导鞭毛抗原H11血清凝集为阳性,37℃诱导鞭毛抗原血清凝集为阴性;毒力基因检测结果显示stx1和eae基因阳性,其余均为阴性;菌株鉴定为EHEC O26∶H11。结论 28℃Swarm琼脂可诱导鞭毛H11,肠出血性大肠杆菌O26∶H11鉴定时应检测相关毒力基因。

Objective Flagellum antigen of EHEC O26∶H11 was induced and identified,so as to provide reference method for routine detection. Methods Suspected strains of EHEC O26∶ H11 were conducted for biochemical identification and serotyping. At 37 ℃ and at 28 ℃,induced effects of flagellum antigen were compared by Swarm; diarrheagenic Escherichia coli virulence genes of eae,stx1,stx2,lt,st,bfp A,aggR and ipa H were detected by fluorescence quantitative PCR. Results H11 flagellum antigen were positive at 28 ℃,and at 37 ℃ it was negative. Virulence gene detection results showed stx1 and eae were positive,and the rest were negative; the strain was identified as EHEC O26∶H11. Conclusion Flagellum antigen can be induced by Swarm at 28 ℃; in the identification of EHEC O26∶ H11,the relevant virulence genes should be detected.