Bat ticks revisited: Ixodes ariadnae sp. nov. and allopatric genotypes of I. vespertilionis in caves of Hungary.
ABSTRACT: BACKGROUND: In Europe two ixodid bat tick species, Ixodes vespertilionis and I. simplex were hitherto known to occur. METHODS: Bat ticks were collected from cave walls and bats in Hungary. Their morphology and genotypes were compared with microscopy and conventional PCR (followed by sequencing), respectively. RESULTS: A year-round activity of I. vespertilionis was observed. Molecular analysis of the cytochrome oxidase subunit I (COI) gene of twenty ticks from different caves showed that the occurrence of the most common genotype was associated with the caves close to each other. A few specimens of a morphologically different tick variant were also found and their COI analysis revealed only 86-88% sequence homology with I. simplex and I. vespertilionis, respectively. CONCLUSIONS: The microenvironment of caves (well separated from each other) appears to support the existence of allopatric I. vespertilionis COI genotypes, most likely related to the distance between caves and to bat migration over-bridging certain caves. The name I. ariadnae sp. nov. is given to the new tick species described here for the first time.
Project description:Phylogeographical studies allow precise genetic comparison of specimens, which were collected over large geographical ranges and belong to the same or closely related animal species. These methods have also been used to compare ticks of veterinary-medical importance. However, relevant data are missing in the case of ixodid ticks of bats, despite (1) the vast geographical range of both Ixodes vespertilionis and Ixodes simplex, and (2) the considerable uncertainty in their taxonomy, which is currently unresolvable by morphological clues.In the present study 21 ticks were selected from collections or were freshly removed from bats or cave walls in six European and four Asian countries. The DNA was extracted and PCRs were performed to amplify part of the cytochrome oxidase I (COI), 16S and 12S rDNA genes, followed by sequencing for identification and molecular-phylogenetic comparison.No morphological differences were observed between Ixodes vespertilionis specimens from Spain and from other parts of Europe, but corresponding genotypes had only 94.6 % COI sequence identity. An I. vespertilionis specimen collected in Vietnam was different both morphologically and genetically (i.e. with only 84.1 % COI sequence identity in comparison with I. vespertilionis from Europe). Two ticks (collected in Vietnam and in Japan) formed a monophyletic clade and shared morphological features with I. ariadnae, recently described and hitherto only reported in Europe. In addition, two Asiatic specimens of I. simplex were shown to differ markedly from European genotypes of the same species. Phylogenetic relationships of ticks showed similar clustering patterns with those of their associated bat host species.Although all three ixodid bat tick species evaluated in the present study appear to be widespread in Eurasia, they exhibit pronounced genetic differences. Data of this study also reflect that I. vespertilionis may represent a species complex.
Project description:BACKGROUND:Parasites may actively seek for hosts and may use a number of adaptive strategies to promote their reproductive success and host colonization. These strategies will necessarily influence their host specificity and seasonality. Ticks are important ectoparasites of vertebrates, which (in addition to directly affecting their hosts) may transmit a number of pathogens. In Europe, three hard tick species (Ixodidae: Ixodes ariadnae, I. simplex and I. vespertilionis) and at least two soft tick species (Argasidae: Argas transgariepinus and A. vespertilionis) are specialized for bats. METHODS:Here we report data on the host range of these ticks and the seasonality of tick infestation on wild caught bats in south-east Europe. We collected 1803 ticks from 30 species of bats living in underground shelters (caves and mines) from Romania and Bulgaria. On the basis of tick-host associations, we tested several hypotheses on host-parasite evolutionary adaptations regulating host specificity, seasonality and sympatric speciation. RESULTS:We observed significant differences in host specificity and seasonality of abundance between the morphologically different bat specialist ticks (I. simplex and I. vespertilionis) likely caused by their host choice and their respective host-seeking behavior. The two highly generalist, but morphologically similar tick species (I. ariadnae and I. vespertilionis) showed temporal differences in occurrence and activity, thus exploiting significantly different host communities while occurring in geographical sympatry. CONCLUSIONS:We conclude that bat-specialist ticks show a wide range of adaptations to their hosts, with differences in specificity, seasonality of occurrence, the prevalence and intensity of infestation and all these contribute to a successful division of temporal niches of ticks sharing morphologically similar hosts occurring in geographical sympatry.
Project description:Recently a new hard tick species, Ixodes ariadnae has been discovered, adding to the two known ixodid tick species (I. vespertilionis and I. simplex) of bats in Europe.Scanning electron microscopic comparison of adult females of these species shows morphological differences concerning the palps, the scutum, the Haller's organ, the coxae, as well as the arrangement and fine structure of setae. Molecular analysis of 10 geographically different isolates revealed 90-95% sequence homology in the 12S and 16S rDNA genes of bat tick species. Based on 12S rDNA sequences, genotypes of I. ariadnae clustered closest to I. simplex, whereas according to their 16S rDNA gene they were closest to I. vespertilionis. The subolesin gene of I. ariadnae had only 91% sequence homology with that of I. ricinus, and is the longest known among hard tick species.The present study illustrates the morphology and clarifies the phylogenetic relationships of the three known bat tick species that occur in Europe. According to its subolesin gene I. ariadnae may have a long evolutionary history.
Project description:In this study 308 ticks (Ixodes ariadnae: 26 larvae, 14 nymphs, five females; I. vespertilionis: 89 larvae, 27 nymphs, eight females; I. simplex: 80 larvae, 50 nymphs, nine females) have been collected from 200 individuals of 17 bat species in two countries, Hungary and Romania. After DNA extraction these ticks were molecularly analysed for the presence of piroplasm DNA. In Hungary I. ariadnae was most frequently identified from bat species in the family Vespertilionidae, whereas I. vespertilionis was associated with Rhinolophidae. Ixodes ariadnae was not found in Romania. Four, four and one new bat host species of I. ariadnae, I. vespertilionis and I. simplex were identified, respectively. DNA sequences of piroplasms were detected in 20 bat ticks (15 larvae, four nymphs and one female). I. simplex carried piroplasm DNA sequences significantly more frequently than I. vespertilionis. In I. ariadnae only Babesia vesperuginis DNA was detected, whereas in I. vespertilionis sequences of both B. vesperuginis and B. crassa. From I. simplex the DNA of B. canis, Theileria capreoli, T. orientalis and Theileria sp. OT3 were amplified, as well as a shorter sequence of the zoonotic B. venatorum. Bat ticks are not known to infest dogs or ruminants, i.e. typical hosts and reservoirs of piroplasms molecularly identified in I. vespertilionis and I. simplex. Therefore, DNA sequences of piroplasms detected in these bat ticks most likely originated from the blood of their respective bat hosts. This may indicate either that bats are susceptible to a broader range of piroplasms than previously thought, or at least the DNA of piroplasms may pass through the gut barrier of bats during digestion of relevant arthropod vectors. In light of these findings, the role of bats in the epidemiology of piroplasmoses deserves further investigation.
Project description:BACKGROUND:Ixodes collaris Hornok, 2016 is a recently discovered tick species associated with bats in Asia. This study provides the description of the male and the larva, as well as high quality drawings of all stages. METHODS:Ticks were collected from cave walls and bats in Phia Oac (Vietnam). DNA was extracted from one individual of each stage/sex, while another was morphometrically analysed. Based on two genetic markers, all ticks were identified as I. collaris. RESULTS:The male of I. collaris has long legs (i.e. the length of Haller's organ exceeds the maximum diameter of tarsus I), unlike the male of I. simplex Neumann, 1906, but similarly to males of I. vespertilionis Koch, 1844 and I. ariadnae Hornok, 2014. The lateral and medial edges of the palpi of male I. collaris are both convexly curved, unlike in I. ariadnae and I. simplex, but similarly to I. vespertilionis. The male of I. collaris has long palpal setae (up to 210 µm), unlike the males of I. ariadnae (30-100 µm) and I. simplex (20-80 µm), but similarly to I. vespertilionis (100-200 µm). Males of I. collaris have sparse distribution of long palpal setae (vs dense in I. vespertilionis) and posteriorly diverging, sclerotized trapezoid ridge dorsally on the basis capituli (posteriorly convergent, U-shaped and less evident in I. vespertilionis). The larva of I. collaris has long legs (unlike the larva of I. simplex, but similarly to I. vespertilionis and I. ariadnae), elongated club-shaped palpi (240 × 70 vs 200 × 90 µm in I. ariadnae, 200 × 70 µm in I. vespertilionis; and 140 × 60 µm in I. simplex:), pentagonal scutum, which is longer than broad (different from I. ariadnae and I. simplex, but similar to that of I. vespertilionis). The larva of I. collaris has strongly concave caudolateral margin of ventral basis with perpendicular angle (vs slightly concave, with obtuse angle in I. vespertilionis) and a prominent, dark sclerotized edge, "collar" (absent in I. vespertilionis). CONCLUSION:Several features allow to distinguish the male and the larva of I. collaris morphologically from those of other bat-associated ixodid tick species.
Project description:Ticks host a wide range of zoonotic pathogens and are a significant source of diseases that affect humans and livestock. However, little is known about the pathogens associated with bat ticks. We have collected ectoparasites from bat carcasses over a seven year period. Nucleic acids (DNA and RNA) were extracted from 296 ticks removed from bats and the species designation was confirmed in all ticks as Argas (Carios) vespertilionis. A subset of these samples (n?=?120) were tested for the presence of zoonotic pathogens by molecular methods. Babesia species, Rickettsia spp., within the spotted fever group (SFG), and Ehrlichia spp. were detected in ticks removed from 26 bats submitted from 14 counties across England. The prevalence of Rickettsia spp. was found to be highest in Pipistrellus pipistrellus from southern England. This study suggests that the tick species that host B. venatorum may include the genus Argas in addition to the genus Ixodes. As A. vespertilionis has been reported to feed on humans, detection of B. venatorum and SFG Rickettsia spp. could present a risk of disease transmission in England. No evidence for the presence of flaviviruses or Issyk-Kul virus (nairovirus) was found in these tick samples.
Project description:<label>BACKGROUND</label>Recently, a high degree of mitochondrial gene heterogeneity was demonstrated between conspecific ixodid ticks of bats in Eurasia. Argas vespertilionis is a soft tick species of mainly vespertilionid bats, also with a wide distribution in the Old World. The aim of this study was to investigate the morphology, mitochondrial gene heterogeneity and host range of A. vespertilionis in the Old World.<label>RESULTS</label>Altogether 318 soft tick larvae were collected from 17 bat species (belonging to six genera) in seven countries. Based on the general morphology (setal arrangement) of 314 A. vespertilionis larvae, and the detailed measurements of fifteen larvae, only minor morphological differences (in dorsal plate size and the type of serrate setae) were observed between specimens from Europe and Vietnam. On the other hand, cytochrome c oxidase subunit 1 (cox1) and 16S rRNA gene sequence analyses of 17 specimens showed that A. vespertilionis from Europe is genetically different (with up to 7.5% cox1 and 5.7% 16S rRNA gene sequence divergence) from specimens collected in Vietnam, and their phylogenetic separation is well supported.<label>CONCLUSION</label>In its evaluated geographical range, no larval phenotypic differences justify the existence of separate species under the name A. vespertilionis. However, phylogenetic analyses based on two mitochondrial markers suggest that it represents a complex of at least two putative cryptic species. The broad host range of A. vespertilionis might partly explain its lower degree of mitochondrial gene heterogeneity in comparison with ixodid bat tick species over the same geographical region of Eurasia.
Project description:BACKGROUND:Despite the increasingly recognized eco-epidemiological significance of bats, data from molecular analyses of vector-borne bacteria in bat ectoparasites are lacking from several regions of the Old and New Worlds. METHODS:During this study, six species of ticks (630 specimens) were collected from bats in Hungary, Romania, Italy, Kenya, South Africa, China, Vietnam and Mexico. DNA was extracted from these ticks and analyzed for vector-borne bacteria with real-time PCRs (screening), as well as conventional PCRs and sequencing (for pathogen identification), based on the amplification of various genetic markers. RESULTS:In the screening assays, Rickettsia DNA was only detected in bat soft ticks, whereas Anaplasma phagocytophilum and haemoplasma DNA were present exclusively in hard ticks. Bartonella DNA was significantly more frequently amplified from hard ticks than from soft ticks of bats. In addition to Rickettsia helvetica detected by a species-specific PCR, sequencing identified four Rickettsia species in soft ticks, including a Rickettsia africae-like genotype (in association with a bat species, which is not known to migrate to Africa), three haemotropic Mycoplasma genotypes in Ixodes simplex, and Bartonella genotypes in I. ariadnae and I. vespertilionis. CONCLUSIONS:Rickettsiae (from both the spotted fever and the R. felis groups) appear to be associated with soft rather than hard ticks of bats, as opposed to bartonellae. Two tick-borne zoonotic pathogens (R. helvetica and A. phagocytophilum) have been detected for the first time in bat ticks. The present findings add Asia (China) to the geographical range of R. lusitaniae, as well as indicate the occurrence of R. hoogstraalii in South Africa. This is also the first molecular evidence for the autochthonous occurrence of a R. africae-like genotype in Europe. Bat haemoplasmas, which are closely related to haemoplasmas previously identified in bats in Spain and to "Candidatus Mycoplasma haemohominis", are reported here for the first time from Central Europe and from any bat tick.
Project description:BACKGROUND:Increasing molecular evidence supports that bats and/or their ectoparasites may harbor vector-borne bacteria, such as bartonellae and borreliae. However, the simultaneous occurrence of rickettsiae in bats and bat ticks has been poorly studied. METHODS:In this study, 54 bat carcasses and their infesting soft ticks (n = 67) were collected in Shihezi City, northwestern China. The heart, liver, spleen, lung, kidney, small intestine and large intestine of bats were dissected, followed by DNA extraction. Soft ticks were identified both morphologically and molecularly. All samples were examined for the presence of rickettsiae by amplifying four genetic markers (17-kDa, gltA, ompA and ompB). RESULTS:All bats were identified as Pipistrellus pipistrellus, and their ticks as Argas vespertilionis. Molecular analyses showed that DNA of Rickettsia parkeri, R. lusitaniae, R. slovaca and R. raoultii was present in bat organs/tissues. In addition, nine of the 67 bat soft ticks (13.43%) were positive for R. raoultii (n = 5) and R. rickettsii (n = 4). In the phylogenetic analysis, these bat-associated rickettsiae clustered together with conspecific sequences reported from other host and tick species, confirming the above results. CONCLUSIONS:To the best of our knowledge, DNA of R. parkeri, R. slovaca and R. raoultii was detected for the first time in bat organs/tissues. This is also the first molecular evidence for the presence of R. raoultii and R. rickettsii in bat ticks. To our knowledge, R. parkeri was not known to occur in Asia. Our results highlight the need to assess rickettsial agents in a broader range of bat species and associated tick species.
Project description:Argas vespertilionis, an argasid tick associated with bats and bat habitats in Europe, Africa, and Asia has been reported to bite humans; however, studies investigating the presence of vector-borne pathogens in these ticks are lacking. Using molecular tools, we tested 5 A. vespertilionis ticks collected in 2010 from the floor of a bat-infested attic in southwestern France that had been converted into bedrooms. Rickettsia sp. AvBat, a new genotype of spotted fever group rickettsiae, was detected and cultivated from 3 of the 5 ticks. A new species of the Ehrlichia canis group, Ehrlichia sp. AvBat, was also detected in 3 ticks. Four ticks were infected with Borrelia sp. CPB1, a relapsing fever agent of the Borrelia group that caused fatal borreliosis in a bat in the United Kingdom. Further studies are needed to characterize these new agents and determine if the A. vespertilionis tick is a vector and/or reservoir of these agents.