Pesquisa de agentes patogénicos em carraças ixodídeas de mamíferos silvestres
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As carraças da família Ixodidae são artrópodes hematófagos com distribuição global, atuando como vetores de diversos agentes patogénicos que podem causar perdas económicas na produção pecuária e representar riscos significativos para a saúde humana e animal. Os mamíferos selvagens podem atuar como reservatórios potenciais de agentes como Ehrlichia spp., Anaplasma spp. e Borrelia spp., contribuindo para a sua manutenção nos ecossistemas naturais. O presente estudo teve como objetivo caracterizar a infestação por carraças da família Ixodidae em mamíferos selvagens admitidos em dois centros de reabilitação de fauna silvestre, localizados no norte de Portugal e na região centro-oeste da Irlanda. Adicionalmente, pretendeu-se realizar o rastreio molecular de Borrelia spp., Anaplasma spp. e Ehrlichia spp. nos espécimes recolhidos. As carraças foram recolhidas em mamíferos selvagens admitidos no Centro de Recuperação de Animais Selvagens do Hospital Veterinário da Universidade de Trás-os-Montes e Alto Douro e no Kildare Wildlife Rescue, na região centro-oeste da Irlanda. Os espécimes recolhidos foram identificados morfologicamente ao nível da espécie por estereomicroscopia, com recurso a chaves taxonómicas. Um subconjunto representativo das carraças recolhidas foi submetido a rastreio molecular para deteção de Anaplasma spp./Ehrlichia spp. e Borrelia spp., por PCR convencional, utilizando primers específicos de género dirigidos aos genes 16S rRNA e flaB, respetivamente. Os fragmentos amplificados foram sequenciados e posteriormente analisados por BLAST e por análise filogenética para identificação ao nível da espécie. Foram recolhidas um total de 420 carraças provenientes de 54 hospedeiros pertencentes a 7 espécies diferentes de mamíferos silvestres. De entre os exemplares de carraças recolhidos, foram identificados 57 Ixodes ricinus, 62 Ixodes hexagonus, 280 Rhipicephalus sanguineus, 1 Rhipicephalus pusillus, 11 Rhipicephalus spp. e 9 ninfas de espécies não identificadas. Um total de 30 carraças das espécies Ixodes ricinus, Rhipicephalus sanguineus e Rhipicephalus spp. produziram amplicões PCR compatíveis com Borrelia spp., enquanto 8 carraças de Rhipicephalus sanguineus e Ixodes ricinus geraram amplicões compatíveis com Anaplasma spp./Ehrlichia spp. Na análise filogenética de uma amostra de Borrelia spp., a sequência agrupou-se num grupo monofilético com suporte bootstrap de 100%, juntamente com sequências de referência de Borrelia garinii. A espécie B. garinii foi detetada numa carraça Rhipicephalus sanguineus recolhida num Genetta genetta. Os resultados confirmam a presença de agentes bacterianos dos géneros Borrelia, Anaplasma/Ehrlichia em carraças recolhidas de mamíferos selvagens no norte de Portugal e na Irlanda. A deteção da espécie zoonótica Borrelia garinii numa carraça Rhipicephalus sanguineus recolhida num Genetta genetta sugere que os mamíferos selvagens poderão funcionar como potenciais hospedeiros e reservatórios de carraças infetadas, contribuindo para a manutenção e disseminação de agentes patogénicos zoonóticos transmitidos por carraças. Estes resultados salientam a necessidade de uma vigilância integrada no âmbito da abordagem One Health.
Ticks from the Ixodidae family are hematophagous arthropods with a global distribution, acting as vectors for various pathogens that can cause economic losses in livestock production and pose significant risks to human and animal health. Wild mammals can act as potential reservoirs for agents such as Ehrlichia spp., Anaplasma spp. and Borrelia spp., contributing to their maintenance in natural ecosystems. The aim of this study was to characterize infestation by ticks from the Ixodidae family in wild mammals admitted to two wildlife rehabilitation centers, located in northern Portugal and central-west Ireland. This study also aimed to carry out molecular screening for Borrelia spp., Anaplasma spp. and Ehrlichia spp. in the specimens collected. The ticks were collected from wild mammals admitted to the Wild Animal Rehabilitation Center of the Veterinary Hospital of the University of Trás-os-Montes e Alto Douro and the Kildare Wildlife Rescue, in central-west Ireland. The specimens collected were identified morphologically to species level using stereomicroscopy and taxonomic keys. A representative subset of the ticks collected was molecularly screened for Anaplasma spp./Ehrlichia spp. and Borrelia spp. by conventional PCR, using genus-specific primers targeting the 16S rRNA and flaB genes, respectively. The amplified fragments were sequenced and subsequently analyzed by BLAST and phylogenetic analysis for species-level identification. A total of 420 ticks were collected from 54 hosts belonging to 7 different species of wild mammals. Among the tick specimens collected, 57 Ixodes ricinus, 62 Ixodes hexagonus, 280 Rhipicephalus sanguineus, 1 Rhipicephalus pusillus, 11 Rhipicephalus spp. and 9 nymphs of unidentified species were identified. A total of 30 ticks from Ixodes ricinus, Rhipicephalus sanguineus and Rhipicephalus spp. produced PCR amplicons compatible with Borrelia spp, while 8 ticks from Rhipicephalus sanguineus and Ixodes ricinus generated amplicons compatible with Anaplasma spp./Ehrlichia spp. In the phylogenetic analysis of a Borrelia spp. sequence, the sequence clustered in a monophyletic group with 100% bootstrap support, together with Borrelia garinii reference sequences. This B. garinii was detected in a Rhipicephalus sanguineus tick collected from a Genetta genetta. The results confirm the presence of bacterial agents of the genera Borrelia, Anaplasma and Ehrlichia in ticks collected from wild mammals in northern Portugal and Ireland. The detection of the zoonotic species Borrelia garinii in a Rhipicephalus sanguineus tick collected from a Genetta genetta suggests that wild mammals may act as potential hosts and reservoirs for infected ticks, contributing to the maintenance and spread of zoonotic pathogens transmitted by ticks. These results highlight the need for integrated surveillance as part of the One Health approach.
Ticks from the Ixodidae family are hematophagous arthropods with a global distribution, acting as vectors for various pathogens that can cause economic losses in livestock production and pose significant risks to human and animal health. Wild mammals can act as potential reservoirs for agents such as Ehrlichia spp., Anaplasma spp. and Borrelia spp., contributing to their maintenance in natural ecosystems. The aim of this study was to characterize infestation by ticks from the Ixodidae family in wild mammals admitted to two wildlife rehabilitation centers, located in northern Portugal and central-west Ireland. This study also aimed to carry out molecular screening for Borrelia spp., Anaplasma spp. and Ehrlichia spp. in the specimens collected. The ticks were collected from wild mammals admitted to the Wild Animal Rehabilitation Center of the Veterinary Hospital of the University of Trás-os-Montes e Alto Douro and the Kildare Wildlife Rescue, in central-west Ireland. The specimens collected were identified morphologically to species level using stereomicroscopy and taxonomic keys. A representative subset of the ticks collected was molecularly screened for Anaplasma spp./Ehrlichia spp. and Borrelia spp. by conventional PCR, using genus-specific primers targeting the 16S rRNA and flaB genes, respectively. The amplified fragments were sequenced and subsequently analyzed by BLAST and phylogenetic analysis for species-level identification. A total of 420 ticks were collected from 54 hosts belonging to 7 different species of wild mammals. Among the tick specimens collected, 57 Ixodes ricinus, 62 Ixodes hexagonus, 280 Rhipicephalus sanguineus, 1 Rhipicephalus pusillus, 11 Rhipicephalus spp. and 9 nymphs of unidentified species were identified. A total of 30 ticks from Ixodes ricinus, Rhipicephalus sanguineus and Rhipicephalus spp. produced PCR amplicons compatible with Borrelia spp, while 8 ticks from Rhipicephalus sanguineus and Ixodes ricinus generated amplicons compatible with Anaplasma spp./Ehrlichia spp. In the phylogenetic analysis of a Borrelia spp. sequence, the sequence clustered in a monophyletic group with 100% bootstrap support, together with Borrelia garinii reference sequences. This B. garinii was detected in a Rhipicephalus sanguineus tick collected from a Genetta genetta. The results confirm the presence of bacterial agents of the genera Borrelia, Anaplasma and Ehrlichia in ticks collected from wild mammals in northern Portugal and Ireland. The detection of the zoonotic species Borrelia garinii in a Rhipicephalus sanguineus tick collected from a Genetta genetta suggests that wild mammals may act as potential hosts and reservoirs for infected ticks, contributing to the maintenance and spread of zoonotic pathogens transmitted by ticks. These results highlight the need for integrated surveillance as part of the One Health approach.