Prevalence, Infection Intensity and Molecular Diagnosis of Mixed Infections with Metastrongylus spp. (Metastrongylidae) in Wild Boars in Uzbekistan

The aim of the present study was to characterize the diversity of Metastrongylus spp. in wild boars and the earthworm intermediate host species contributing to the maintenance of the life cycle. Here, wild boars were subjected to parasitological necropsies, and lungworm species were identified morphologically, followed by confirmation using ITS-2 sequencing and a phylogenetic analysis. Earthworms were collected from wild boar habitats and investigated for the presence of larvae. The prevalence of Metastrongylus spp. in wild boars was 78.8%, and many individuals were positive for all three detected species, Metastrongylus pudendotectus, Metastrongylus salmi and Metastrongylus elongatus. The phylogenetic analysis did not clearly resolve all species, except for M. pudendotectus. Age group and season had no influence on prevalence, while intensity was significantly higher in autumn than in spring and summer (Kruskal–Wallis followed by Dunn’s test). Three out of six investigated earthworm species were positive for metastrongyloid larvae (prevalence of 10.4–16.7%), but neither their phylogenetic relationship nor ecological microhabitats were able to explain these differences. Further sequence data should be used to improve the resolution in phylogenetic trees to determine potential cryptic species in the genus, while the application of deep sequencing approaches might provide insights into species-specific epidemiology and pathology

Prevalence, Infection Intensity and Molecular Diagnosis of Mixed Infections with Metastrongylus spp. (Metastrongylidae) in Wild Boars in Uzbekistan

The aim of the present study was to characterize the diversity of Metastrongylus spp. in wild boars and the earthworm intermediate host species contributing to the maintenance of the life cycle. Here, wild boars were subjected to parasitological necropsies, and lungworm species were identified morphologically, followed by confirmation using ITS-2 sequencing and a phylogenetic analysis. Earthworms were collected from wild boar habitats and investigated for the presence of larvae. The prevalence of Metastrongylus spp. in wild boars was 78.8%, and many individuals were positive for all three detected species, Metastrongylus pudendotectus, Metastrongylus salmi and Metastrongylus elongatus. The phylogenetic analysis did not clearly resolve all species, except for M. pudendotectus. Age group and season had no influence on prevalence, while intensity was significantly higher in autumn than in spring and summer (Kruskal–Wallis followed by Dunn’s test). Three out of six investigated earthworm species were positive for metastrongyloid larvae (prevalence of 10.4–16.7%), but neither their phylogenetic relationship nor ecological microhabitats were able to explain these differences. Further sequence data should be used to improve the resolution in phylogenetic trees to determine potential cryptic species in the genus, while the application of deep sequencing approaches might provide insights into species-specific epidemiology and pathology

ウズベク共和国における Protostrongylidae 科線虫の中間宿主 : 腹足類

Protostrongylid species are causative agents of pulmonary protostrongyliasis in caprine species in Uzbekistan. These nematodes typically require one intermediate host, terrestrial mollusks, to complete their life cycle. In this study, eight species of gastropods were found to be positive for protostrongylid larvae. Haplotypes of larvae corresponding to sequences of Protostrongylus rufescens and Muellerius capillaris were detected. Morphological identification of gastropods, based on shell characteristics, revealed six different morphotypes. Anatomic-morphological and molecular results confirmed the membership of these gastropods to the Buliminidae, Hygromiidae, Agriolimacidae and Parmacellidae and revealed eight different species: Pseudonapaeus maydanika, P. sogdiana, P. albiplicatus, Pseudonapaeus sp., Angiomphallia regeliana, Xeropicta candacharica, Candaharia levanderi and Deroceras reticulatum. This study displays the first report of P. maydanika, C. levanderi and D. reticulatum as natural intermediate hosts of M. capillaris. The infection rate of snails with protostrongylids was 27.9%(616/2,207) and the infection rate of slugs was 6.5%(18/279).ウズベク共和国における羊の肺虫症の原因寄生虫プロトストロンギルス科線虫は陸棲腹足類を中間宿主としているので、この線虫症の疫学では腹足類の調査が必須であった。そこで、同国において貝殻の形態で 6種に分類された軟体類を対象にプロトストロンギルス科の感染幼虫の保有状況を調査した。その結果、分子生物学的にProtostrongylus rufescens および Muellerius capillaris のハプロタイプに一致した感染幼虫を得た。また、今回、幼虫が得られた腹足類について解剖学および分子生物学的な検討によりこれらは 4つの科 Buliminidae, Hygromiidae, Agriolimacidae あるいは Parmacellidae の次のような 8種に同定された; Pseudonapaeus maydanika, P. sogdiana, P. albiplicatus, Pseudonapaeus sp. Angiomphallia regeliana, Xeropicta candacharica, Candaharia levanderi, Deroceras reticulatum. 本研究により P. maydanika, Candaharia levanderi および D. reticulatum が M. capillaris の自然中間宿主であることが証明された。全体的なプロトストロンギルス科線虫の感染幼虫の保有率はカタツムリ類で 27.9%(616/2,207)、一方、ナメクジ類では 6.5%(18/279)と低かった