The prevalence of Trichinella spiralis in farmed minks (Neovison vison) associated with exposure to wild rats (Rattus norvegicus) in Shandong province, China

Abstract

Background Both of American mink (Neovison vison) and wild rat (Rattus norvegicus) is considered reservoir hosts carrying many endoparasites. Trichinella is a successful parasitic nematode including nine species and three genotypes with a worldwide distribution. However, little is known about the prevalence of Trichinella infection in mink (Neovison vison) and rat (Rattus norvegicus) in China.Methods In total, 289 muscle samples of minks and 102 rat carcasses were collected between April 2017 and December 2019 in Weihai city of Shandong province, China. The food of minks including chicken skeleton and mashed marine products was also collected at 3 batches. All the samples were used to examine for the appearance of Trichinella by the pooled artificial HCl-pepsin digestion method. The isolates from minks and rats were identified as T. spiralis by multiplex PCR. Then, the phylogenetic tree was constructed based on the sequences of 5S rDNA inter-gene spacer regions.Results Muscle larvae were detected in 20 out of 289 minks (6.92%) and in 2 of 102 wild rats (1.96%), respectively. The intensity of Trichinella in mink samples was ranged from 0.025 to 0.815 lpg, while the larval burden in rats was 0.17 lpg. The isolates from minks and rats were identified as T. spiralis by multiplex PCR. Sequence analysis revealed a 100% identical alignment of the 5S rDNA inter-gene spacer regions from the two isolates. The phylogenetic tree confirmed the two isolates from minks and rats belonging to T. spiralis based on analysis of the 5S rDNA inter-gene spacer sequence.Conclusions The present study represents the first report of T. spiralis infection in American mink (Neovison vison) and wild rat (Rattus norvegicus) from Shandong province, China. The farmed minks would be vulnerable to Trichinella infection through exposure to the wild rats. The prevalence of T. spiralis in wild rats may raise a public health concern for the potential zoonotic risk for the domestic animals.

The genus Trichinella and its presence in wildlife worldwide: A review

“…was identified as another allochthonous host of Trichinella spp., as reported in Poland, Russia and China, with an overall prevalence of 2.07% (Hurníková et al, 2016;Seryodkin et al, 2020;Zhang et al, 2020). The reported hosts for the different Trichinella spp.…”

“…The racoon dog ( Nyctereutes procyonoides ), which presented with an overall prevalence rate of 12.25%, is an allochthonous species introduced in the ex‐Union of Soviet Socialist Republics in 1929; then, its distribution expanded to Europe, and it has rapidly become an important part of the reservoir of Trichinella in the Palearctic (Dudzinski et al., 1963; Pannwitz et al., 2010; Paulauskas et al., 2016). In addition to the raccoon dog in Europe, the American mink ( Neovison vison ) was identified as another allochthonous host of Trichinella spp., as reported in Poland, Russia and China, with an overall prevalence of 2.07% (Hurníková et al., 2016; Seryodkin et al., 2020; Zhang et al., 2020). The reported hosts for the different Trichinella spp.…”