L型变异对结核分枝杆菌耐药性的影响及机制

The influence mechanism of L-form variation on drug resistance of mycobacterium tuberculosis

目的观察L型变异对结核分枝杆菌耐药性的影响。方法将结核分枝杆菌H37Rv细菌型诱导为L型菌株;分离临床标本中的结核分枝杆菌L型菌株。观察结核分枝杆菌L型对一线抗结核药物的敏感性;提取诱导和临床分离的结核分枝杆菌L型菌株的DNA,进行耐药相关基因测序,分析其与结核分枝杆菌L型表型变异的关系。结果诱导结核分枝杆菌标准菌株H37Rv形成的L型对异烟肼、利福平、乙胺丁醇和链霉素均耐药。诱导的L型的基因型与结核分枝杆菌标准菌株H37Rv一致,没有发生改变。临床分离株表现出更为复杂的耐药性。结论结核分枝杆菌L型的表型变异可以造成结核分枝杆菌的耐药性增加,结核分枝杆菌L型的表型变异与其耐药性相关。

Objective To observe the influence of L - form variation on the drug - resistance of mycobacterium tuberculosis. Methods L -form bacteria induced from H37Rv strains of Mycobacterium tuberculosis and those isolated from clinical speci- mens were involved to observe the sensitivity to first - line antituberculosis drugs. DNA of these mycobacterium tuberculosis L - form isolates was extracted for resistance - related gene sequences, so as to find the correlation between drug resistance and phenotypic variation of mycobacterium tuberculosis L - form isolates. Results The mycobacterium tuberculosis L - form strains in- duced from H37Rv strains showed drug resistance to isoniazid, rifampicin, ethambutol and streptomycin, but maintained consistent gene sequence with Mycobacterium tuberculosis H37Rv strains. While clinical mycobacterium tuberculosis L - form isolates exhibited more complex drug resistance. Conclusion There was correlation between phenotypic variation and drug resistance of mycobacterium tuberculosis L- form variants, the former can increase the later.