Morphological identification and phylogenetic analysis of Eimeria coypi and Eimeria fluviatilis (Apicomplexa: Eimeriidae) isolated from nutrias (Myocastor coypus [Rodentia]) in Japan.
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引用次数: 0
Abstract
The nutria (Myocastor coypus) is a semiaquatic rodent that originally inhabited South America. However, the animals have spread to different continents as alien species, and their numbers are quickly increasing, especially in North America, Europe, and Eastern Asia including Japan. Although nutrias have been suggested to serve as reservoirs for pathogens, including parasites, there have been few reports on this subject. In the present study, we surveyed the gastrointestinal parasites in nutrias living in Japan to better understand their prevalence in nutrias. We collected 72 samples of intestinal contents or feces from nutrias in Osaka and Okayama Prefectures. We found that 49 (68.1 %) samples were positive for Eimeria parasites, and two types of oocysts were identified: ellipsoidal (Type A) and subspherical (Type B) oocysts. In addition, Strongyloides myopotami was detected in 44 samples, and Capillaria spp. and Fasciola spp. were detected in one and three samples, respectively. Based on the morphologies of the detected Eimeria oocysts, Types A and B were identified to be E. coypi and E. fluviatilis, respectively. Phylogenetic analyses after PCR and sequencing targeting the cytochrome c oxidase subunit I gene placed the sequences of E. fluviatilis (Type B) as a cluster between the sequences of Eimeria derived from rodents. The sequences of the three subgenotypes of E. coypi (Type A) were included in the cluster containing the sequences of Eimeria spp. from rodents of multiple species, which is referred to as the Apionodes supercluster, and is separate from other clades. It has been suggested that Eimeria spp. from rodents in this cluster can quickly adapt to infect different hosts. Although further analyses are needed to construct more detailed phylogenetic trees, our results revealed the genetical positions of Eimeria spp. in nutrias. In addition, our results may be helpful when considering host specificity as well as host switching by the pathogen.
期刊介绍:
Systematic Parasitology publishes papers on the systematics, taxonomy and nomenclature of the following groups: Nematoda (including plant-parasitic), Monogenea, Digenea, Cestoda, Acanthocephala, Aspidogastrea, Cestodaria, Arthropoda (parasitic copepods, hymenopterans, mites, ticks, etc.), Protozoa (parasitic groups), and parasitic genera in other groups, such as Mollusca, Turbelleria, etc. Systematic Parasitology publishes fully illustrated research papers, brief communications, and fully illustrated major revisions. In order to maintain high standards, all contributors describing new taxa are asked to state clearly where the holotype is deposited and to make paratypes available for examination by the referees. It is recognized that, in some cases, this may cause problems for the authors, but it is hoped that by adhering to this rule authors may be protected against rapid synonymy of their taxa, and the types will be preserved for posterity.