Ross Ian L, Heuzenroeder Michael W
Infectious Diseases Laboratories, Institute of Medical and Veterinary Science, Rundle Mall P.O., Adelaide, South Australia 5000, Australia.
Int J Med Microbiol. 2009 Aug;299(6):410-20. doi: 10.1016/j.ijmm.2008.12.002. Epub 2009 Feb 12.
Two novel molecular typing methods, multiple-locus variable-number tandem repeats (VNTR) analysis (MLVA) and multiple amplification of phage loci typing (MAPLT), were compared with pulsed-field gel electrophoresis (PFGE) for the discrimination of 128 Salmonella enterica serovar Enteritidis (S. Enteritidis) isolates. Selected epidemiologically unrelated isolates represented a cross-section of phage types routinely isolated in Australia and included 28 isolates that could not be assigned a phage type. Targeting 5 previously described loci, MLVA generated 61 different profiles with a Simpson index of diversity of DI=0.968. MLVA locus STTR-5 proved to be the most diverse with 11 different alleles detected with a Nei's diversity index value of D=0.769. Using 8 MAPLT primers previously developed for S. Typhimurium produced 36 different profiles with a DI value of 0.948. By contrast, PFGE only generated 13 different pulsed-field patterns, DI=0.873. Within each phage type there was variation in the extent to which either molecular method was able to discriminate the S. Enteritidis isolates. MAPLT provided more discrimination in terms of the number of profiles and DI value for phage type 1 and the untypable strains while MLVA was more discriminatory for phage types 14var and 26. There was a general lack of concordance of either molecular assay to phage type. These results suggest that both MAPLT and MLVA have excellent potential as tools for epidemiological studies of S. Enteritidis.
将两种新型分子分型方法，多位点可变数目串联重复序列（VNTR）分析（MLVA）和噬菌体位点多重扩增分型（MAPLT），与脉冲场凝胶电泳（PFGE）进行比较，以区分128株肠炎沙门氏菌肠炎亚种（肠炎沙门氏菌）分离株。选择的流行病学上不相关的分离株代表了澳大利亚常规分离的噬菌体类型的一个横截面，包括28株无法指定噬菌体类型的分离株。针对5个先前描述的位点，MLVA产生了61种不同的图谱，辛普森多样性指数DI = 0.968。MLVA位点STTR-5被证明是最多样化的，检测到11个不同的等位基因，内氏多样性指数值D = 0.769。使用先前为鼠伤寒沙门氏菌开发的8种MAPLT引物产生了36种不同的图谱，DI值为0.948。相比之下，PFGE仅产生了13种不同的脉冲场模式，DI = 0.873。在每种噬菌体类型中，两种分子方法能够区分肠炎沙门氏菌分离株的程度存在差异。对于噬菌体类型1和不可分型菌株，MAPLT在图谱数量和DI值方面提供了更多的区分度，而MLVA对噬菌体类型14var和26的区分度更高。两种分子检测方法与噬菌体类型之间普遍缺乏一致性。这些结果表明，MAPLT和MLVA作为肠炎沙门氏菌流行病学研究工具都具有巨大潜力。
