志贺菌毒力相关基因的PCR检测分析

目的：利用PCR方法对武汉地区近年来收集的17株志贺菌进行毒力相关基因检测并分析其分布情况。方法：采用8对引物set1A、set1B、shet2A、shet2B、ial、ipaH、stx1与virA分别对志贺菌中毒力相关基因进行检测,结合常规鉴定方法对PCR扩增结果进行分析。结果：SHET1仅在福氏志贺菌（福氏Ⅱ型、福氏Ⅳ型）分离株（包括其标准株）中存在;SH-ET2存在于各型志贺菌（包括其标准株）;ipaH基因存在于各种类型志贺菌（包括其标准株）;17株志贺菌中,引物shet2A和引物shet2B用于检测sen基因分别检出16株和13株;ial、virA在反复复苏的菌株中检出率有所下降,stx1基因只在痢疾志贺菌中检出。结论：志贺菌快速诊断方法（PCR）中应首选检测志贺菌相关毒力基因ipaH基因。

Detection of virulence genes in Shigella by PCR

Objective:A total of 17 strains of Shigella flexneri isolated from Shigellae outbreaks in Wuhan city were detected and analyzed for the distribution of virulence genes by PCR assay.Methods:We designed 8 pairs of probes of PCR assay for detection of the virulence genes including set1A,set1B,sen(SHET2),ial,ipaH,stx1 and virA in Shigella at the same time.Combining with conventional methods,the results were discussed.Results:SHET1 have been detected only in isolates of Shigella flexneri,SHET2 was present in various Shigella serotypes including isolated samples and the reference strains.All Shigella species that we studied were positive for ipaH gene.primer shet2A and primer shet2B had 16 and 13 positives in 17 Shigella flexneri isolates,respectively.Moreover,ial,virA genes had significant negatives upon repeated subculturing and prolonged storage.Conclusion:Primer shet2A are more reliant than primer shet2B in the detection of sen gene.Moreover,ial,virA genes prone to lost or delete upon repeated subculturing and prolonged storage.The study shows ipaH gene could be used in detection of Shigella spp.by PCR.