Nejvíce citovaný článek - PubMed ID 31253201
Anaplasma phagocytophilum evolves in geographical and biotic niches of vertebrates and ticks
BACKGROUND: Ixodes inopinatus was described from Spain on the basis of morphology and partial sequencing of 16S ribosomal DNA. However, several studies suggested that morphological differences between I. inopinatus and Ixodes ricinus are minimal and that 16S rDNA lacks the power to distinguish the two species. Furthermore, nuclear and mitochondrial markers indicated evidence of hybridization between I. inopinatus and I. ricinus. In this study, we tested our hypothesis on tick dispersal from North Africa to Southern Europe and determined the prevalence of selected tick-borne pathogens (TBPs) in I. inopinatus, I. ricinus, and their hybrids. METHODS: Ticks were collected in Italy and Algeria by flagging, identified by sequencing of partial TROSPA and COI genes, and screened for Borrelia burgdorferi s.l., B. miyamotoi, Rickettsia spp., and Anaplasma phagocytophilum by polymerase chain reaction and sequencing of specific markers. RESULTS: Out of the 380 ticks, in Italy, 92 were I. ricinus, 3 were I. inopinatus, and 136 were hybrids of the two species. All 149 ticks from Algeria were I. inopinatus. Overall, 60% of ticks were positive for at least one TBP. Borrelia burgdorferi s.l. was detected in 19.5% of ticks, and it was significantly more prevalent in Ixodes ticks from Algeria than in ticks from Italy. Prevalence of Rickettsia spotted fever group (SFG) was 51.1%, with significantly greater prevalence in ticks from Algeria than in ticks from Italy. Borrelia miyamotoi and A. phagocytophilum were detected in low prevalence (0.9% and 5.2%, respectively) and only in ticks from Italy. CONCLUSIONS: This study indicates that I. inopinatus is a dominant species in Algeria, while I. ricinus and hybrids were common in Italy. The higher prevalence of B. burgdorferi s.l. and Rickettsia SFG in I. inopinatus compared with that in I. ricinus might be due to geographical and ecological differences between these two tick species. The role of I. inopinatus in the epidemiology of TBPs needs further investigation in the Mediterranean Basin.
- Klíčová slova
- Anaplasma phagocytophilum, B. miyamotoi, Borrelia burgdorferi s.l., Ixodes inopinatus, Ixodes ricinus, Rickettsia SFG, Algeria, Hybrids, Italy,
- MeSH
- Anaplasma phagocytophilum genetika izolace a purifikace klasifikace MeSH
- Borrelia burgdorferi genetika izolace a purifikace klasifikace MeSH
- Borrelia genetika izolace a purifikace klasifikace MeSH
- hybridizace genetická MeSH
- klíště * mikrobiologie MeSH
- nemoci přenášené klíšťaty epidemiologie mikrobiologie MeSH
- prevalence MeSH
- Rickettsia * izolace a purifikace genetika klasifikace MeSH
- RNA ribozomální 16S genetika MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Alžírsko epidemiologie MeSH
- Itálie epidemiologie MeSH
- Názvy látek
- RNA ribozomální 16S MeSH
BACKGROUND: Anaplasma phagocytophilum is characterized by a worldwide distribution and distinguished from other Anaplasmataceae by the broadest range of mammalian hosts and high genetic diversity. The role carnivores play in the life cycle of A. phagocytophilum in Europe is uncertain. Currently, only the red fox is considered a suitable reservoir host. In this study, we focused on native and invasive medium-sized carnivore species that live in sympatry and represent the most abundant species of wild carnivores in Poland. METHODS: A total of 275 individual spleen samples from six carnivore species (Vulpes vulpes, Meles meles, Procyon lotor, Nyctereutes procyonoides and Martes spp.) were screened combining nested PCR and sequencing for A. phagocytophilum targeting a partial groEL gene with subsequent phylogenetic analysis inferred by the maximum likelihood method. RESULTS: The DNA of A. phagocytophilum was detected in 16 of 275 individuals (5.8%). Eight unique genetic variants of A. phagocytophilum were obtained. All detected haplotypes clustered in the clade representing European ecotype I. Three variants belonged to the subclade with European human cases together with strains from dogs, foxes, cats, and wild boars. CONCLUSIONS: While carnivores might have a restricted role in the dissemination of A. phagocytophilum due to their relatively low to moderate infection rates, they hold significance as hosts for ticks. Consequently, they could contribute to the transmission of tick-borne infections to humans indirectly, primarily through tick infection. This underscores the potential risk of urbanization for the A. phagocytophilum life cycle, further emphasizing the need for comprehensive understanding of its ecological dynamics.
- Klíčová slova
- Anaplasma phagocytophilum, Carnivores, Invasive species, Martes spp., Meles meles, Nyctereutes procyonides, Procyon lotor, Vulpes vulpes,
- MeSH
- Anaplasma phagocytophilum * genetika MeSH
- Carnivora * MeSH
- fylogeneze MeSH
- klíšťata * MeSH
- lidé MeSH
- Mustelidae * MeSH
- prasata MeSH
- psi MeSH
- Sus scrofa MeSH
- sympatrie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- psi MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Polsko epidemiologie MeSH
BACKGROUND: Vector-borne pathogens (VBPs) are a major threat to humans, livestock and companion animals worldwide. The combined effect of climatic, socioeconomic and host composition changes favours the spread of the vectors, together with the expansion of invasive carnivores contributing to the spread of the pathogens. In Europe, the most widespread invasive species of carnivores are raccoons (Procyon lotor) and raccoon dogs (Nyctereutes procyonoides). This study focused on the detection of four major groups of VBPs namely Babesia, Hepatozoon, Anaplasma phagocytophilum and Bartonella in invasive and native carnivores in the Czech Republic, with the emphasis on the role of invasive carnivores in the eco-epidemiology of said VBPs. METHODS: Spleen samples of 84 carnivores of eight species (Canis aureus, Canis lupus, Lynx lynx, P. lotor, Martes foina, Lutra lutra, Mustela erminea and N. procyonoides) were screened by combined nested PCR and sequencing for the above-mentioned VBPs targeting 18S rRNA and cytB in hemoprotozoa, groEL in A. phagocytophilum, and using multilocus genotyping in Bartonella spp. The species determination is supported by phylogenetic analysis inferred by the maximum likelihood method. RESULTS: Out of 84 samples, 44% tested positive for at least one pathogen. Five different species of VBPs were detected in P. lotor, namely Bartonella canis, Hepatozoon canis, Hepatozoon martis, A. phagocytophilum and Bartonella sp. related to Bartonella washoensis. All C. lupus tested positive for H. canis and one for B. canis. Three VBPs (Hepatozoon silvestris, A. phagocytophilum and Bartonella taylorii) were detected in L. lynx for the first time. Babesia vulpes and yet undescribed species of Babesia, not previously detected in Europe, were found in N. procyonoides. CONCLUSIONS: Wild carnivores in the Czech Republic are hosts of several VBPs with potential veterinary and public health risks. Among the studied carnivore species, the invasive raccoon is the most competent host. Raccoons are the only species in our study where all the major groups of studied pathogens were detected. None of the detected pathogen species were previously detected in these carnivores in North America, suggesting that raccoons adapted to local VBPs rather than introduced new ones. Babesia vulpes and one new, probably imported species of Babesia, were found in raccoon dogs.
- Klíčová slova
- Anaplasma phagocytophilum, Babesia, Bartonella, Carnivores, Hepatozoon, Invasive species, Vector-borne pathogens,
- MeSH
- Babesia * genetika MeSH
- Carnivora * MeSH
- fylogeneze MeSH
- lidé MeSH
- Lynx * MeSH
- mývalové MeSH
- psík mývalovitý MeSH
- vydry * MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika epidemiologie MeSH
BACKGROUND: Although the tick-borne pathogen Anaplasma phagocytophilum is currently described as a single species, studies using genetic markers can distinguish groups of variants associated with different hosts, pathogenicity, zoonotic potential and biotic and geographic niches. The objective of our study was to investigate the genetic diversity of A. phagocytophilum and Ixodes ricinus ticks attached to people. METHODS: In collaboration with a commercial diagnostic company, a total of 52 DNA samples were obtained from ticks that tested positive for A. phagocytophilum by quantitative PCR. The genetic profile of each sample was determined using the groEL and ankA genes. Identification of the tick species was confirmed by partial sequencing of the COI subunit and a portion of the TROSPA gene. RESULTS: All 52 ticks were identified as I. ricinus. Two protocols of nested PCR amplifying 1293- and 407-bp fragments of groEL of A. phagocytophilum yielded amplicons of the expected size for all 52 samples. Among all sequences, we identified 10 unique genetic variants of groEL belonging to ecotype I and ecotype II. The analysis targeting ankA was successful in 46 of 52 ticks. Among all sequences, we identified 21 unique genetic variants phylogenetically belonging to three clusters. CONCLUSIONS: Our results indicate that ticks attached to people harbor distant genetic variants of A. phagocytophilum, some of which are not recognized as zoonotic. Further studies are needed to determine the risk of human infection by genetic variants other than those designated as zoonotic.
- Klíčová slova
- Anaplasma phagocytophilum, Anaplasmosis, Genetic diversity, Infectious diseases, Ixodes ricinus,
- MeSH
- Anaplasma phagocytophilum * genetika MeSH
- ekotyp MeSH
- klíště * MeSH
- lidé MeSH
- polymerázová řetězová reakce MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The way in which European genetic variants of Anaplasma phagocytophilum circulate in their natural foci and which variants cause disease in humans or livestock remains thus far unclear. Red deer and roe deer are suggested to be reservoirs for some European A. phagocytophilum strains, and Ixodes ricinus is their principal vector. Based on groEL gene sequences, five A. phagocytophilum ecotypes have been identified. Ecotype I is associated with the broadest host range, including strains that cause disease in domestic animals and humans. Ecotype II is associated with roe deer and does not include zoonotic strains. In the present study, questing I. ricinus were collected in urban, pasture, and natural habitats in the Czech Republic, Germany, and Slovakia. A fragment of the msp2 gene of A. phagocytophilum was amplified by real-time PCR in DNA isolated from ticks. Positive samples were further analyzed by nested PCRs targeting fragments of the 16S rRNA and groEL genes, followed by sequencing. Samples were stratified according to the presence/absence of roe deer at the sampling sites. Geographic origin, habitat, and tick stage were also considered. The probability that A. phagocytophilum is a particular ecotype was estimated by a generalized linear model. Anaplasma phagocytophilum was identified by genetic typing in 274 I. ricinus ticks. The majority belonged to ecotype I (63.9%), 28.5% were ecotype II, and both ecotypes were identified in 7.7% of ticks. Ecotype II was more frequently identified in ticks originating from a site with presence of roe deer, whereas ecotype I was more frequent in adult ticks than in nymphs. Models taking into account the country-specific, site-specific, and habitat-specific aspects did not improve the goodness of the fit. Thus, roe deer presence in a certain site and the tick developmental stage are suggested to be the two factors consistently influencing the occurrence of a particular A. phagocytophilum ecotype in a positive I. ricinus tick.
- Klíčová slova
- Anaplasma phagocytophilum, Ixodes ricinus, deer, ecotype,
- MeSH
- Anaplasma phagocytophilum genetika izolace a purifikace MeSH
- ekosystém MeSH
- ekotyp MeSH
- klíště genetika mikrobiologie MeSH
- lidé MeSH
- RNA ribozomální 16S genetika MeSH
- vysoká zvěř mikrobiologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Evropa MeSH
- Názvy látek
- RNA ribozomální 16S MeSH