Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata, Anthrax Reference Institute of Italy-Foggia, Italy.
BMC Vet Res. 2010 Feb 28;6:11. doi: 10.1186/1746-6148-6-11.
In Italy, anthrax is endemic but occurs sporadically. During the summer of 2004, in the Pollino National Park, Basilicata, Southern Italy, an anthrax epidemic consisting of 41 outbreaks occurred; it claimed the lives of 124 animals belonging to different mammal species. This study is a retrospective molecular epidemiological investigation carried out on 53 isolates collected during the epidemic. A 25-loci Multiple Locus VNTR Analysis (MLVA) MLVA was initially performed to define genetic relationships, followed by an investigation of genetic diversity between epidemic strains through Single Nucleotide Repeat (SNR) analysis.
53 Bacillus anthracis strains were isolated. The 25-loci MLVA analysis identified all of them as belonging to a single genotype, while the SNR analysis was able to detect the existence of five subgenotypes (SGTs), allowing a detailed epidemic investigation. SGT-1 was the most frequent (46/53); SGTs 2 (4/53), 3 (1/53) 4 (1/53) and 5 (1/53) were detected in the remaining seven isolates.
The analysis revealed the prevalent spread, during this epidemic, of a single anthrax clone. SGT-1--widely distributed across the epidemic area and present throughout the period in question - may, thus, be the ancestral form. SGTs 2, 3 and 4 differed from SGT-1 at only one locus, suggesting that they could have evolved directly from the latter during the course of this epidemic. SGT-5 differed from the other SGTs at 2-3 loci. This isolate, thus, appears to be more distantly related to SGT-1 and may not be a direct descendant of the lineage responsible for the majority of cases in this epidemic. These data confirm the importance of molecular typing and subtyping methods for in-depth epidemiological analyses of anthrax epidemics.
在意大利，炭疽病是地方性的，但偶有散发。2004 年夏天，在意大利南部巴西利卡塔的波里诺国家公园，发生了一场由 41 起疫情组成的炭疽病疫情，导致 124 种不同哺乳动物死亡。本研究对疫情期间采集的 53 株分离株进行了回顾性分子流行病学调查。采用 25 个基因座多位点可变数目串联重复序列分析（MLVA）进行初步遗传关系分析，然后通过单核苷酸重复（SNR）分析研究流行菌株的遗传多样性。
共分离出 53 株炭疽杆菌。25 个基因座 MLVA 分析发现所有菌株均属于单一基因型，而 SNR 分析能够检测到 5 个亚基因型（SGTs）的存在，从而可以进行详细的疫情调查。SGT-1 最为常见（46/53）；其余 7 株分离株中检测到 SGT-2（4/53）、SGT-3（1/53）、SGT-4（1/53）和 SGT-5（1/53）。
分析显示，在此次疫情中，单一炭疽克隆广泛传播。SGT-1 在疫区广泛分布，在整个疫情期间均存在，可能是原始形式。SGT-2、SGT-3 和 SGT-4 与 SGT-1 仅在一个基因座上存在差异，表明它们可能是在疫情期间由后者直接进化而来。SGT-5 与其他 SGTs 在 2-3 个基因座上存在差异。因此，该分离株与 SGT-1 的亲缘关系较远，可能不是导致此次疫情大部分病例的谱系的直接后代。这些数据证实了分子分型和亚型分析方法对于炭疽病疫情深入流行病学分析的重要性。
