Investigation of the invasion of multidrug and extensively drug-resistant Mycobacterium tuberculosis in Asian countries

我们收集了结核分枝杆菌临床分离株，分析了利福平和异烟肼耐药与基因突变的相关性，重点分析了缅甸、孟加拉国和尼泊尔这些国家对多重耐药和广泛耐药结核病的调查不足。在缅甸，耐利福平结核分枝杆菌的ropB编码区和耐异烟肼结核分枝杆菌的katG编码区和inha调控区的突变率分别为71.3%和72.5%。相反，在其他两个国家观察到的相关性更高。耐利福平和异烟肼结核分枝杆菌在孟加拉国分别为95.0%和94.5%，在尼泊尔分别为97.2%和93.8%。此外，在孟加拉国的218个多重耐药菌株中分别发现了7个广泛耐药的结核分枝杆菌。在尼泊尔的109个多重耐药菌株中，分别发现了13个广泛耐药结核病。所有这些分离株对卡那霉素和氟喹诺酮类药物的耐药性分别携带RRS和gyrA或gyrB突变。由于不同国家耐药与基因突变的相关性不同，在引入基于基因的药敏试验之前，阐明耐药相关基因显得尤为重要。

We have collected clinical isolates of Mycobacterium tuberculosis and analyzed the correlation between rifampicin and isoniazid resistance and gene mutations by focusing on Myanmar, Bangladesh and Nepal those where the survey of multi and extensively drug-resistant tuberculosis is not sufficient. In Myanmar, mutation rate for ropB encoding region of rifampicin resistant M. tuberculosis and that in katG encoding and inhA regulatory region of isoniazid resistant M. tuberculosis were 71.3 and 72.5%, respectively. On the contrary, higher correlations were observed in other two countries. Those for rifampicin and isoniazid resistant M. tuberculosis were 95.0 and 94.5 %, respectively, in Bangladesh and 97.2 and 93.8 %, respectively, in Nepal. In addition, seven extensively drug resistant M. tuberculosis were found from 218 multi drug-resistant strains, respectively, in Bangladesh. Thirteen extensively drug.resistant tuberculosis were found from 109 multi drug-resistant strains, respectively, in Nepal. All of these isolates carried mutations in rrs and gyrA or gyrB for kanamycin and fluoroquinolone resistance, respectively. As correlations between drug resistance and gene mutations were different between countries, the elucidation of drug resistance associating genes before introducing gene based drug susceptibility tests seemed to be important.