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- Author or Editor: Sándor Hornok x
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Here we report a case of canine babesiosis with unusual morphology of the causative agent. A male, seven-week-old Labrador retriever puppy, exhibiting severe anaemia and haemoglobinuria, was presented at the Clinic of Internal Medicine in February 2011. The puppy was euthanised. The most relevant pathological changes were icterus, severe splenomegaly, generalised lymphadenopathy and haemoglobin nephrosis. Samples were collected from various organs for histology within one hour post mortem. Impression smears were also prepared from the spleen after overnight storage at 4 °C. Tissue sections and smears showed the presence of multiple, coccoid intraerythrocytic bodies that measured 1–2 μm and resembled small babesiae. No large piroplasms were seen. DNA was extracted from the spleen, and a conventional PCR was performed for the amplification of a 450-bp region of the 18S rRNA gene of piroplasms. The causative agent was identified as Babesia canis canis, with 99% sequence identity to other European isolates. Sequence identity to B. gibsoni was only 91%. This is the first account to verify that the morphology of the large canine piroplasm, B. canis, can be uniformly small babesia-like post mortem or following the storage of tissue samples.
In order to investigate haemotropic Mycoplasma (formerly Eperythrozoon) infection of goats, blood samples and blood-sucking lice (Linognathus stenopsis) were collected in two goat herds. DNA was extracted from 20 blood samples and from 49 lice allocated to six pools according to host individuals. Haemoplasma infection was detected in four goats by real-time PCR. From the sample with the highest bacterial load the simultaneous presence of M. ovis and ‘Candidatus M. haemoovis’ was demonstrated by cloning and sequencing. Louse pools were haemoplasma negative, including those from bacteraemic animals. However, not only were Anaplasma inclusion bodies seen in blood smears from goats, but relevant PCR-positivity was also detected among lice. This is the first report of a molecular investigation on caprine haemoplasmas, including analysis of their bloodsucking lice. In summary, goats are susceptible to both molecularly characterised ovine haemoplasmas. On the other hand, goat sucking lice (L. stenopsis) do not appear to be potential vectors of these agents.
Abstract
Recently, the occurrence of Ixodes (Pholeoixodes) kaiseri has been reported for the first time in several European countries, but data on the molecular analysis of this hard tick species are still lacking. Therefore, in this study DNA extracts of 28 I. kaiseri (collected from dogs and red foxes in Germany, Hungary and Romania) were screened with reverse line blot hybridisation (RLB), PCR and sequencing for the presence of 43 tick-borne pathogens or other members of their families from the categories of Anaplasmataceae, piroplasms, rickettsiae and borreliae. Rickettsia helvetica DNA was detected in one I. kaiseri female (from a red fox, Romania), for the first time in this tick species. Six ticks (from red foxes, Romania) contained the DNA of Babesia vulpes, also for the first time in the case of I. kaiseri. Molecular evidence of R. helvetica and B. vulpes in engorged I. kaiseri does not prove that this tick species is a vector of the above two pathogens, because they might have been taken up by the ticks from the blood of foxes. In addition, one I. kaiseri female (from a dog, Hungary) harboured Babesia sp. badger type-B, identified for the first time in Hungary and Central Europe (i.e. it has been reported previously from Western Europe and China). The latter finding can be explained by either the susceptibility of dogs to Babesia sp. badger type-B, or by transstadial survival of this piroplasm in I. kaiseri.
Babesia vesperuginis is the only piroplasm known to infect bats. Unlike most members of the genus Babesia, it is probably transmitted by a soft tick species (i.e. Argas vespertilionis). Recently, two studies have been conducted to clarify the phylogenetic status of this species, and both agreed on placing it into a basal position among Babesia sensu stricto (s.s.). However, several important groups of piroplasms were not included in the already reported phylogenetic trees of B. vesperuginis isolates. Therefore, the aim of the present study was to amplify an approx. 950-bp fragment of the cytochrome c oxidase subunit 1 (cox1) gene of B. vesperuginis from A. vespertilionis specimens, and to compare its sequences with those from other piroplasmid groups in a broader phylogenetic context. Sequence comparisons focusing on either 18S rRNA or cox1 genes, as well as phylogenetic analyses involving separate and concatenated 18S rRNA and cox1 sequences indicate that B. vesperuginis is more closely related to the phylogenetic group of Theileriidae than to Babesia s.s. In particular, B. vesperuginis clustered closest to Cytauxzoon felis and the ‘prototheilerid’ B. conradae. The results of this study highlight that B. vesperuginis is a unique and taxonomically important species, which should be included in future studies aimed at resolving the comprehensive phylogeny of Piroplasmida.
Kinetoplastids are flagellated protozoa, including principally free-living bodonids and exclusively parasitic trypanosomatids. In the most species-rich genus, Trypanosoma, more than thirty species were found to infect bats worldwide. Bat trypanosomes are also known to have played a significant role in the evolution of T. cruzi, a species with high veterinary medical significance. Although preliminary data attested the occurrence of bat trypanosomes in Hungary, these were never sought for with molecular methods. Therefore, amplification of an approx. 900-bp fragment of the 18S rRNA gene of kinetoplastids was attempted from 307 ixodid and 299 argasid ticks collected from bats, and from 207 cimicid bugs collected from or near bats in Hungary and Romania. Three samples, one per each bat ectoparasite group, were PCR positive. Sequencing revealed the presence of DNA from free-living bodonids (Bodo saltans and neobodonids), but no trypanosomes were detected. The most likely source of bodonid DNA detected here in engorged bat ectoparasites is the blood of their bat hosts. However, how bodonids were acquired by bats, can only be speculated. Bats are known to drink from freshwater bodies, i.e. the natural habitats of B. saltans and related species, allowing bats to ingest bodonids. Consequently, these results suggest that at least the DNA of bodonids might pass through the alimentary mucosa of bats into their circulation. The above findings highlight the importance of studying bats and other mammals for the occurrence of bodonids in their blood and excreta, with potential relevance to the evolution of free-living kinetoplastids towards parasitism.
Hard ticks and tsetse flies are regarded as the most important vectors of disease agents in Sub-Saharan Africa. With the aim of screening these blood-sucking arthropods for vector-borne pathogens belonging to the family Anaplasmataceae in South-Western Ethiopia, four species of tsetse flies (collected by traps) and seven species of ixodid ticks (removed from cattle) were molecularly analysed. DNA was extracted from 296 individual ticks and from 162 individuals or pools of tsetse flies. Besides known vector–pathogen associations, in Amblyomma cohaerens ticks sequences of Anaplasma marginale and A. phagocytophilum were detected, the latter for the first time in any ticks from cattle in Africa. In addition, part of the gltA gene of Ehrlichia ruminantium was successfully amplified from tsetse flies (Glossina pallidipes). First-time identification of sequences of the above pathogens in certain tick or tsetse fly species may serve as the basis of further epidemiological and transmission studies.
To monitor the emergence of thermophilic, Mediterranean ixodid tick species and tick-borne pathogens in southern Hungary, 348 ticks were collected from shepherd dogs, red foxes and golden jackals during the summer of 2011. Golden jackals shared tick species with both the dog and the red fox in the region. Dermacentor nymphs were collected exclusively from dogs, and the sequence identification of these ticks indicated that dogs are preferred hosts of both D. reticulatus and D. marginatus nymphs, unlike previously reported. Subadults of three ixodid species were selected for reverse line blot hybridisation (RLB) analysis to screen their vector potential for 40 pathogens/groups. Results were negative for Anaplasma, Babesia and Theileria spp. Investigation of D. marginatus nymphs revealed the presence of Ehrlichia canis, Rickettsia massiliae and Borrelia afzelii for the first time in this tick species. These findings broaden the range of those tick-borne agents, which are typically transmitted by Rhipicephalus sanguineus, but may also have Dermacentor spp. as potential or alternative vectors. Ehrlichia canis was also newly detected in Ixodes canisuga larvae from red foxes. In absence of transovarial transmission in ticks this implies that Eurasian red foxes may play a reservoir role in the epidemiology of canine ehrlichiosis.
