Abstract：
Background. The spread of Enterobacteriaceae coproducing carbapenemases, 16S rRNA methylase and mobile colistin resistance proteins (MCRs) has become a serious public health problem worldwide. This study describes two clinical isolates of Klebsiella pneumoniae coharbouring bla IMP-1, armA and mcr-10.Methods. Two clinical isolates of K. pneumoniae resistant to carbapenems and aminoglycosides were obtained from two patients at a hospital in Myanmar. Their minimum inhibitory concentrations (MICs) were determined by broth microdilution methods. The whole-genome sequences were determined by MiSeq and MinION methods. Drug-resistant factors and their genomic environments were determined.Results. The two K. pneumoniae isolates showed MICs of ≥4 and ≥1024 µg ml-1 for carbapenems and aminoglycosides, respectively. Two K. pneumonaie harbouring mcr-10 were susceptible to colistin, with MICs of ≤0.015 µg ml-1 using cation-adjusted Mueller-Hinton broth, but those for colistin were significantly higher (0.5 and 4 µg ml-1) using brain heart infusion medium. Whole-genome analysis revealed that these isolates coharboured bla NDM-1, armA and mcr-10. These two isolates showed low MICs of 0.25 µg ml-1 for colistin. Genome analysis revealed that both bla NDM-1 and armA were located on IncFIIs plasmids of similar size (81 kb). The mcr-10 was located on IncM2 plasmids of sizes 220 or 313 kb in each isolate. These two isolates did not possess a qseBC gene encoding a two-component system, which is thought to regulate the expression of mcr genes.Conclusion. This is the first report of isolates of K. pneumoniae coharbouring bla NDM-1, armA and mcr-10 obtained in Myanmar.
摘要：
背景。产碳青霉烯酶的肠杆菌科细菌的传播，16SrRNA甲基化酶和移动粘菌素抗性蛋白（MCRs）已成为世界范围内严重的公共卫生问题。这项研究描述了两种肺炎克雷伯菌的临床分离株，它们包含blaIMP-1，armA和mcr-10。方法。从缅甸一家医院的两名患者中获得了对碳青霉烯类和氨基糖苷类耐药的肺炎克雷伯菌的两种临床分离株。通过肉汤微量稀释方法确定其最小抑制浓度（MIC）。通过MiSeq和MinION方法测定全基因组序列。确定了耐药因子及其基因组环境。结果。两个肺炎克雷伯菌分离株显示碳青霉烯类和氨基糖苷类的MIC≥4和≥1024µgml-1，分别。两名携带mcr-10的肺炎克雷伯因对粘菌素敏感，使用阳离子调节的Mueller-Hinton肉汤，MIC≤0.015µgml-1，但是使用脑心输注培养基的粘菌素含量明显更高（0.5和4µgml-1）。全基因组分析显示，这些分离株共包含blaNDM-1，armA和mcr-10。这两个分离株对粘菌素的MIC低，为0.25µgml-1。基因组分析显示，blaNDM-1和armA均位于大小相似（81kb）的IncFIs质粒上。mcr-10位于每个分离株中大小为220或313kb的IncM2质粒上。这两个分离株不具有编码双组分系统的qseBC基因，这被认为是调节mcr基因的表达。结论。这是首次报道在缅甸获得的肺炎克雷伯菌共携带blaNDM-1，armA和mcr-10的分离株。
