title: Phylogenetic analysis of entomoparasitic nematodes, potential control agents of flea populations in natural foci of plague.
abstract: Entomoparasitic nematodes are natural control agents for many insect pests, including fleas that transmit Yersinia pestis, a causative agent of plague, in the natural foci of this extremely dangerous zoonosis. We examined the flea samples from the Volga-Ural natural focus of plague for their infestation with nematodes. Among the six flea species feeding on different rodent hosts (Citellus pygmaeus, Microtus socialis, and Allactaga major), the rate of infestation varied from 0 to 21%. The propagation rate of parasitic nematodes in the haemocoel of infected fleas was very high; in some cases, we observed up to 1,000 juveniles per flea specimen. Our study of morphology, life cycle, and rDNA sequences of these parasites revealed that they belong to three distinct species differing in the host specificity. On SSU and LSU rRNA phylogenies, these species representing three genera (Rubzovinema, Psyllotylenchus, and Spilotylenchus), constitute a monophyletic group close to Allantonema and Parasitylenchus, the type genera of the families Allantonematidae and Parasitylenchidae (Nematoda: Tylenchida). We discuss the SSU-ITS1-5.8S-LSU rDNA phylogeny of the Tylenchida with a special emphasis on the suborder Hexatylina.
authors.affiliation: Russian Research Anti-Plague Institute "Microbe", Saratov 410005, Russia.
authors.forename: E I
authors.initials: EI
authors.lastname: Koshel
authors.affiliation: Belozersky Institute of Physical-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russia ; Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow 127994, Russia ; National Research Institute of Physiology, Biochemistry, and Nutrition of Farm Animals, Russian Academy of Agricultural Sciences, Kaluga Region, Borovsk 249013, Russia.
authors.forename: V V
authors.initials: VV
authors.lastname: Aleshin
authors.affiliation: Russian Research Anti-Plague Institute "Microbe", Saratov 410005, Russia.
authors.forename: G A
authors.initials: GA
authors.lastname: Eroshenko
authors.affiliation: Russian Research Anti-Plague Institute "Microbe", Saratov 410005, Russia.
authors.forename: V V
authors.initials: VV
authors.lastname: Kutyrev
mesh_terms: D000818:Animals; D018509:DNA, Helminth / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D006801:Humans; D009348:Nematoda / Q000235:genetics*; D010572:Pest Control, Biological; D010802:Phylogeny; D010930:Plague; D012377:Rodentia; D012426:Russia; D005423:Siphonaptera / Q000469:parasitology*; D015010:Yersinia pestis
chemical_list: D018509:DNA, Helminth; D004275:DNA, Ribosomal