University of Hohenheim, Institute of Environmental and Animal Hygiene, Stuttgart, Germany.
Lett Appl Microbiol. 2013 Oct;57(4):380-4. doi: 10.1111/lam.12140. Epub 2013 Aug 12.
During the routine fingerprinting of outbreak strains of Bacillus anthracis of European and African origin by means of a 31-marker multi-locus variable number of tandem repeats analysis (MLVA), four cultures, two from the Etosha National Park (ENP), Namibia, and two from an outbreak in the Pyrenees in 1997, were found to harbour different genotypes (GTs). To investigate this further, isolates from 10 samples of blood-soaked soil from beneath anthrax carcasses and 18 clinical swabs taken from carcasses in the ENP were examined by a 31-marker MLVA. While only a single GT was found in any one of the 10 soil samples, four of the 18 swabs (22%) yielded different GTs. Two GTs were isolated from each of a zebra and a springbok and three GTs from each of a second zebra and an elephant. These animals had died in a region of the ENP where deaths caused by anthrax regularly occur every year. The results confirm the indications noted previously that co-infection with more than one GT is probably not especially uncommon. The results show that, for the purpose of analysing genotypes involved in an outbreak, it is important to examine more than a single colony from a clinical sample.
Multi-locus variable number of tandem repeats analysis (MLVA)-based fingerprinting techniques have been used in many studies worldwide to characterize the occurrence of different genotypes of Bacillus anthracis in outbreaks of wildlife or livestock and to draw conclusions about the source, the possible routes of spread and the temporal and spatial distribution of outbreak strains. Simultaneous isolation of different genotypes from the same host revealed in our study by MLVA highlights the importance of examining more than a single colony from a clinical sample. This conclusion is not specific for MLVA but holds true for every high-resolution method, including full-genome sequencing.
通过使用 31 标记多位点可变串联重复分析 (MLVA) 对来自欧洲和非洲起源的炭疽杆菌暴发菌株进行常规指纹识别时，发现了四个培养物，两个来自纳米比亚的埃托沙国家公园 (ENP)，两个来自 1997 年在比利牛斯山的暴发。为了进一步调查，对来自炭疽尸骸下血浸土壤的 10 个样本和来自 ENP 尸骸的 18 个临床拭子的分离物进行了 31 标记 MLVA 检查。虽然在任何一个土壤样本中都只发现了一种 GT，但在 18 个拭子中有 4 个 (22%) 产生了不同的 GT。从一匹斑马和一只跳羚中分离出两种 GT，从第二匹斑马和一头大象中分离出三种 GT。这些动物死在 ENP 的一个区域，该区域每年都会因炭疽而死亡。结果证实了先前注意到的迹象，即同时感染两种以上 GT 可能并不特别罕见。结果表明，为了分析暴发中涉及的基因型，重要的是要从临床样本中检查多个以上的单一菌落。
多位点可变串联重复分析 (MLVA)-基于指纹识别技术已在世界范围内用于表征野生动物或牲畜暴发中不同基因型的炭疽杆菌的发生，并得出关于暴发菌株的来源、可能的传播途径以及时空分布的结论。我们的 MLVA 研究同时从同一宿主中分离出不同的基因型，突显了从临床样本中检查多个以上单一菌落的重要性。这一结论不仅适用于 MLVA，也适用于包括全基因组测序在内的每一种高分辨率方法。
