European Union Reference Laboratory for Parasites, Istituto Superiore di Sanità, Rome, Italy.
Animal Health Laboratory, OIE Collaborating Centre for Foodborne Zoonotic Parasites, JRU BIPAR, Anses, ENVA, INRA, Université Paris Est, Maisons-Alfort, France.
Parasit Vectors. 2018 Jun 19;11(1):353. doi: 10.1186/s13071-018-2939-9.
The zoonotic nematode Trichinella britovi was discovered in two neighboring Mediterranean islands of Corsica and Sardinia, almost simultaneously at the beginning of the 21st century. An epidemiological link between the two parasite populations was generally assumed. In 2015, an outbreak of trichinellosis in Nice, the South of France, was reportedly caused by the consumption of raw pork delicatessen imported from Corsica. The aims of the present study were to investigate, by multilocus genotype (MLG) analyses, the hypothesis of the common origin of the Corsican and Sardinian T. britovi foci and to trace "from fork to farm" the origin of the pork product, which caused a trichinellosis outbreak in mainland France in 2015.
Sixty-three T. britovi isolates were collected from animals and pork products of Sardinia and Corsica islands and from mainland of Italy, France and Spain. We analyzed genetic variability at four polymorphic microsatellite loci by two independent algorithms, the Bayesian and multivariate analyses, to evaluate the genetic relationships of 1367 single larvae.
Trichinella britovi isolates of the two islands showed different genetic structures and the Bayesian analysis revealed a different membership of the two insular populations. Furthermore, two geographically separate genetic groups were identified among Corsican isolates. Lastly, the origin of the pork delicatessen marketed in Nice was linked to a breeder-butcher in Corsica.
The low level of genetic admixture of the insular T. britovi isolates suggests that this pathogen colonized the two islands by separate events. On the other hand in Corsica, although the isolates share the same genetic structure, geographically separate isolates showed different membership. We suggest the MLG analysis as a suitable method in supporting epidemiological investigations to trace "from fork to farm" insular populations of T. britovi.
在 21 世纪初，在相邻的两个地中海岛屿科西嘉岛和撒丁岛几乎同时发现了人畜共患旋毛虫 Trichinella britovi。通常认为这两个寄生虫种群之间存在流行病学联系。2015 年，法国南部尼斯发生了一起旋毛虫病暴发，据报道是由于食用了从科西嘉进口的生猪肉熟食。本研究的目的是通过多位点基因型（MLG）分析，调查科西嘉岛和撒丁岛 T. britovi 疫源地起源的共同假设，并追踪 2015 年导致法国大陆暴发旋毛虫病的猪肉产品的“从叉子到农场”起源。
从撒丁岛和科西嘉岛的动物和猪肉产品以及意大利、法国和西班牙的大陆采集了 63 个 T. britovi 分离株。我们通过两种独立的算法，即贝叶斯分析和多变量分析，分析了四个多态微卫星基因座的遗传变异性，以评估 1367 个单幼虫的遗传关系。
两个岛屿的 T. britovi 分离株显示出不同的遗传结构，贝叶斯分析显示两个岛屿种群的成员不同。此外，在科西嘉岛分离株中还鉴定出两个地理上分开的遗传群。最后，在尼斯销售的猪肉熟食的起源与科西嘉岛的一个饲养者屠夫有关。
岛屿 T. britovi 分离株的遗传混合程度较低，表明该病原体通过单独的事件殖民了这两个岛屿。另一方面，在科西嘉岛，尽管分离株具有相同的遗传结构，但地理上分离的分离株具有不同的成员。我们建议 MLG 分析是一种支持流行病学调查的合适方法，以追踪 T. britovi 岛屿种群的“从叉子到农场”。
