以噻吩二羧酸肼实验结果作为鉴定牛分枝杆菌依据的可靠性研究

Evaluation of the reliability of thiophen-2-carboxylic acid hydrazine result for the identification ofMycobacterium bovis

目的评估以噻吩二羧酸肼（TCH）实验结果作为鉴定牛分枝杆菌主要依据的可靠性。方法使用对硝基苯甲酸和TCH培养基对4069株分枝杆菌临床分离株进行鉴定，并将对MTB复合群中对5mg／L的TCH敏感菌株再次接种至含2mg／L的TCH罗氏培养基中进行敏感度测试，同时采用间隔区寡核苷酸分型技术和多伉点PCR技术对TCH敏感菌株进行鉴定。结果4069株分枝杆菌临床分离株中有3929株属于MTB复合群菌株，3929株中对5mg／L的TCH实验敏感菌株为245株，245株中对2mg／LTCH仍敏感的菌株为20株，间隔区寡核苷酸分型技术和多位点PCR技术鉴定出245株分离株中仪有1株为牛分枝杆菌。结论TCH实验浓度不论是5mg／L还是2mg／L，均难以成为鉴定牛分枝杆菌的可靠依据。

Objective To evaluate the reliability of thiophen-2-earboxylie acid hydrazine （TCH） test for identification of Mycobacterium boris （ M. boris ）. Methods A total of 4069 clinically isolated strains were identified by P-Nitrobenzoic acid medimn （500 rag/L） and TCH medium （5 rag/L） . Mycobacterium tuberculosis （ M. tuberculosis ） complex strains susceptible to 5 mg/L TCH were further tested for susceptibility to 2 mg/L TCH. Spacer oligonucleotide typing （spoligotyping） and multi-loci PCR were also performed to identify TCH susceptible strains. Results Among the 4069 isolated strains there were 3929 strains belonging to M. tuberculosis complex （MTBC） of which 245 were susceptible to 5 mg/L TCH. Of these 245 strains, 20 were also susceptible to 2 mg/L TCH, while only 1 strain was identified to be M. bovis by both spoligotyping and multi-loci PCR. Conclusion TCH susceptibility test （ either 5 mg/L or 2 mg/L） is not a reliable method for identification of M. boris.