Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi 221 005, India.
Infect Genet Evol. 2010 May;10(4):530-6. doi: 10.1016/j.meegid.2010.02.004. Epub 2010 Feb 13.
Salmonella enterica serotype Typhi strains (n=113) were isolated from typhoid patients over a period of 2 decades, i.e. 1987-2006. RAPD and ERIC PCR methods were used for random whole genome typing of these strains. ERIC PCR was found to be very efficient with the discriminatory index (DI) of 0.9821 with 100% reproducibility. RAPD was satisfactory in discriminating the strains (DI=0.8978) but with poor reproducibility (40%). However, composite genotypic analysis was still better with DI of 0.9981 but with inherent poor reproducibility due to RAPD. Two major clones were observed to be circulating in the community with few unrelated strains too. The dendrogram constructed based on ERIC PCR banding pattern by involving 89 Typhi strains revealed 71 patterns, indicating that the genome of the bacterium is capable of rapid changes and variations. Thus, the spectrum of biological manifestations of human infection by S. Typhi may be related to its capacity for genetic diversity underlined by its highly plastic hypermutable genome.
在 20 年的时间里，即 1987 年至 2006 年，从伤寒患者中分离出了 113 株伤寒沙门氏菌血清型 Typhi 菌株。使用随机扩增多态性 DNA（RAPD）和肠杆菌基因间重复一致序列 PCR（ERIC PCR）方法对这些菌株进行了全基因组随机分型。ERIC PCR 非常有效，其鉴别指数（DI）为 0.9821，重现性为 100%。RAPD 在菌株的鉴别方面令人满意（DI=0.8978），但重现性较差（40%）。然而，复合基因型分析的 DI 仍然更高，为 0.9981，但由于 RAPD，重现性较差。在社区中发现了两种主要的流行克隆，也存在少数不相关的菌株。涉及 89 株伤寒沙门氏菌的 ERIC PCR 带型构建的系统发育树显示出 71 种模式，表明细菌的基因组能够快速发生变化和变异。因此，人类感染伤寒沙门氏菌的生物学表现谱可能与其高度可塑的高突变基因组所强调的遗传多样性能力有关。
