一起疑似炭疽疫苗菌株毒力恢复事件中炭疽芽孢杆菌的毒力鉴定与分析

Analysis and identification on Bacillus anthracis virulence in the event of the anthrax vaccine suspected virulence recovery

目的对某校疑似炭疽疫苗菌株毒力恢复事件(事件)中,教学实验使用的炭疽芽孢杆菌毒力及其环境污染情况进行鉴定和调查,为合理处理该事件提供参考依据。方法调查事件发生的情况、采集实验用培养物、冻存菌株和实验室环境样本。对实验用培养物进行噬菌体裂解和青霉素敏感试验鉴定;选取炭疽芽孢杆菌的rpoB基因和毒力相关的pagA和capC基因,应用TaqMan荧光探针法对采集样本进行检测。结果实验用培养物的噬菌体裂解试验显示有明显的噬菌斑,青霉素敏感试验显示在青霉素纸片周围有明显的抑菌环,并且培养物和冻存菌株rpoB和pagA基因检测为阳性,capC基因检测为阴性;教学场所的环境样本rpoB、pagA和capC基因检测均为阴性。结论该事件中实验用培养物和冻存菌株均为缺少capC基因的减毒炭疽芽孢杆菌,未发现毒力恢复情况;教学场所中无炭疽芽孢杆菌的污染。

Objective To investigate the virulence and the environmental contamination of Bacillus anthracis used in a teaching experiment in the event of a anthrax vaccine suspected virulence recovery,and provide scientific basis for disposing the event.Methods Weinvestigated the event and collected the experimental culture,frozen strain and the environmental samples concerning the teaching experiments;The culture was identified by phage lysis and penicillin sensitivity test;The rpoB gene on chromosome,pagA gene on plasmids pXO1 and capC gene on plasmids pXO2 of the culture,frozen strain and the related environmental samples were detected by TaqMan real-time PCR assay.Results The results showed that there were obvious phage plaque and clear zone around penicillin slip on the culture.The detection of rpoB and pagA genes was positive,but the capC gene was negative in the culture and the frozen strain.The detection of rpoB,pagA and capC genes of Bacillus anthracis was all negative in the environment samples from the teaching sites.Conclusion The culture and the frozen strain were Bacillus anthracis without capC gene,and the virulence recovery of anthrax vaccine was not found in the event.There was no contamination of Bacillus anthracis in the teaching sites.