Kim Byoung-Jun, Yi Su-Yeon, Shim Tae-Sun, Do Seung Yeon, Yu Hee-Kyung, Park Young-Gil, Kook Yoon-Hoh, Kim Bum-Joon
Cancer Research Institute, Institute of Endemic Diseases, Seoul National University Medical Research Center-SNUMRC, Seoul National University College of Medicine, Seoul, Republic of Korea.
PLoS One. 2012;7(6):e38420. doi: 10.1371/journal.pone.0038420. Epub 2012 Jun 5.
So far, genetic diversity among strains within Mycobacterium massiliense has rarely been studied. To investigate the genetic diversity among M. massiliense, we conducted phylogenetic analysis based on hsp65 (603-bp) and rpoB (711-bp) sequences from 65 M. massiliense Korean isolates. We found that hsp65 sequence analysis could clearly differentiate them into two distinct genotypes, Type I and Type II, which were isolated from 35 (53.8%) and 30 patients (46.2%), respectively. The rpoB sequence analysis revealed a total of four genotypes (R-I to R-IV) within M. massiliense strains, three of which (R-I, R-II and R-III) correlated with hsp65 Type I, and other (R-IV), which correlated with Type II. Interestingly, genotyping by the hsp65 method agreed well with colony morphology. Despite some exceptions, Type I and II correlated with smooth and rough colonies, respectively. Also, both types were completely different from one another in terms of MALDI-TOF mass spectrometry profiles of whole lipid. In addition, we developed PCR-restriction analysis (PRA) based on the Hinf I digestion of 644-bp hsp65 PCR amplicons, which enables the two genotypes within M. massiliense to be easily and reliably separated. In conclusion, two distinct hsp65 genotypes exist within M. massiliense strains, which differ from one another in terms of both morphology and lipid profile. Furthermore, our data indicates that Type II is a novel M. massiliense genotype being herein presented for the first time. The disparity in clinical traits between these two hsp65 genotypes needs to be exploited in the future study.
到目前为止，马赛分枝杆菌菌株间的遗传多样性鲜有研究。为了调查马赛分枝杆菌的遗传多样性，我们基于65株韩国分离的马赛分枝杆菌的hsp65（603bp）和rpoB（711bp）序列进行了系统发育分析。我们发现，hsp65序列分析能够将它们清晰地分为两个不同的基因型，即I型和II型，分别从35例（53.8%）和30例患者（46.2%）中分离得到。rpoB序列分析显示，马赛分枝杆菌菌株内共有四种基因型（R-I至R-IV），其中三种（R-I、R-II和R-III）与hsp65 I型相关，另一种（R-IV）与II型相关。有趣的是，hsp65方法进行的基因分型与菌落形态高度一致。尽管存在一些例外情况，但I型和II型分别与光滑菌落和粗糙菌落相关。此外，两种类型在全脂的基质辅助激光解吸电离飞行时间质谱图谱方面也完全不同。另外，我们基于对644bp的hsp65 PCR扩增产物进行Hinf I酶切开发了PCR-限制性分析（PRA），这使得能够轻松且可靠地分离马赛分枝杆菌内的两种基因型。总之，马赛分枝杆菌菌株内存在两种不同的hsp65基因型，它们在形态和脂质谱方面均存在差异。此外，我们的数据表明II型是一种首次在此呈现的新型马赛分枝杆菌基因型。这两种hsp65基因型在临床特征上的差异有待在未来研究中进一步探索。
