Title
Tick-borne pathogens in Ixodidae ticks and their large mammalian hosts in the Russian Far East
Author(s)
Seryodkin, Ivan V. ;Thomas, Lindsay ;Birtles, Richard John ;Lewis, J.;Makenov, Marat ;Petrunenko, Yuri K.;Goodrich, John;Miquelle, Dale G.
Published
2017
Publisher
Parazitologiia (Parasitology)
Abstract
The Russian Far East is characterized by high biological diversity and a large number of mammals, including many rare species such as the Amur tiger Panthera tigris altaica Temminck, 1844, the Far Eastern leopard P. pardus orientalis (Schlegel, 1857), the brown bear Ursus arctos Linnaeus, 1758, and the Asiatic black bear U. thibetanus G. Cuvier, 1823. Population declines of these species are largely due to habitat loss, poaching and reduction of prey species/forage base. However, there is also the risk of population decrease and even extinction due to infectious diseases, which have not been adequately studied in the region. This research was performed to identify tick-borne pathogens in the Ixodidae ticks and large mammals in the Russian Far East and their potential impact on wildlife populations. For this purpose, we examined adult free-ranging and feeding ticks collected from vegetation and from mammals. Ticks (n = 264) were collected from 34 animals, including Amur tigers, lynxes Lynx lynx (Linnaeus, 1758), brown bears, Asiatic black bears, foxes Vulpes vulpes (Linnaeus, 1758), raccoon dogs Nyctereutes procyoides (Gray, 1834), domestic dog Canis familiaris Linnaeus, 1758, red deer Cervus elaphus Linnaeus, 1758 and wild boars Sus scrofa Linnaeus, 1758. Additional ticks (n = 197) were collected from five ground drags in various locations throughout the Russian Far East during the peak tick season (May and June). DNA was extracted by alkaline digestion and two PCR assays were carried out. The first assay looked for the presence of rickettsia-like organisms and was performed on all samples. The second assay looked for the presence of apicomplexan organisms and was performed only on ticks collected from animals. DNA of Rickettsia-like organisms were detected in 46.6 % of the feeding ticks collected from animals and 27.4 % of the ticks collected from ground drags. DNA of Apicomplexan organisms were detected in 34.1 % of the feeding ticks collected from animals. The nucleotide base sequences of five amplicons obtained from rickettsia-like organisms and nine amplicons obtained from apicomplexan organisms were determined. Comparative sequence analysis revealed that the rickettsia-like organisms were likely members of the taxa Candidatus Neoehrlichia mikurensis Kawahara et al., 2004, Anaplasma phagocytophilum (Foggie 1949) Dumler et al., 2001, and Ehrlichia muris Wen et al., 1995. The apicomplexan samples could be delineated into five like strains of Hepatozoon ursi Kubo et al., 2008 (all infecting ticks collected off bears), two likely strains of H. felis (Patton, 1908) (both infecting ticks collected off felids), one close relative of a likely novel Theileria species (currently referred to as Iwate 141), and one close relative of Theileria sinensis Bai et al., 2002. These results indicate the presence of tick-borne pathogens in tick and carnivore populations in the Russian Far East and should be used as a basis for further research to quantify the epidemiologies of infections caused by these potential pathogens.
Keywords
tiger;bears;ticks;tick-borne diseases;Anaplasmatacceae;Apicomplexa;Panthera tigris;Ursus;Hepatozoon;Ixodes;Haemaphysalis
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PUB22842