RESUMO
Argas persicus (the fowl tick) is a species of soft tick commonly associated with poultry farms. It has a wide geographic distribution and colonizes different climate regions. Morphological identification of A. persicus has been reported worldwide, but genetic data regarding its molecular characterization is limited. The present study provides data for morphological identification and genetic characterization of A. persicus collected from domestic birds in traditional farms from east Algeria (Setif region). Additionally, A. persicus samples originating from Gansu province in China were included for comparative molecular study. In total, 1518 ticks collected from 30 infested farms were examined and morphologically identified as A. persicus. Furthermore, the 14 tick samples obtained from China were morphologically identified as A. persicus. Molecular analysis of 30 ticks from Algeria (one tick from each infested farm) and the 14 Chinese samples based on PCR, sequencing, and phylogenetic analysis of three mitochondrial genetic markers (16S rRNA, 12S rRNA, and cox1) confirmed morphological results where all samples belonged to the A. persicus group. However, phylogenetic analysis showed that all Algerian samples and two Chinese samples belong to A. persicus sensu stricto (s.s.), while the remaining Chinese samples represented A. persicus sensu lato (s.l.) (divergent lineage). The present study confirms the occurrence of A. persicus s.s. both in Algeria and China, as well as provides novel molecular data for a distinct Chinese lineage of A. persicus.
Assuntos
Ácaros e Carrapatos , Argas , Argasidae , Carrapatos , Animais , Argasidae/genética , Argas/genética , Ácaros e Carrapatos/genética , Filogenia , RNA Ribossômico 16S/genética , Argélia , Aves , Carrapatos/genéticaRESUMO
Amblyomma species are non-endemic ticks in Egypt, which have been recorded from imported animals. This study was carried out in 2022 to monitor Amblyomma spp. from dromedary camels, cattle, and snakes in Egypt. During this study, 400 camels, 200 cattle, and two snakes (Pythonidae) were inspected for tick infestation. Collected specimens were identified based on morphological characters and confirmed by phylogenetic analysis of the 12S rRNA gene. Camels were infested by adult specimens of Amblyomma variegatum and Amblyomma lepidum, but no Amblyomma spp. were collected from cattle. Amblyomma variegatum showed high genetic similarity to other A. variegatum from Guinea-Bissau and São Tomé (> 99.99%), and A. lepidum showed high genetic similarity to other A. lepidum from Israel and Sudan (99.99%). Amblyomma latum is recorded in Egypt from the ball python snake for the first time and showed high genetic similarity with South African A. latum (99.87%).
Assuntos
Boidae , Doenças dos Bovinos , Ixodidae , Lagartos , Infestações por Carrapato , Bovinos , Animais , Ixodidae/genética , Amblyomma , Egito , Filogenia , Camelus , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/veterináriaRESUMO
The present study reports anomalies in Hyalomma dromedarii and Hyalomma rufipes adults collected from dromedary camels (Camelus dromedarius) in Aswan, Egypt, between January and June 2022. A total of 52 adult ticks displayed one or several local and/or general anomalies. A wide variety of local anomalies was observed including atrophy of one or multiple legs, ectromely, absence of accessory adanal and subanal plates, fusion of adanal and accessory plates, and presence of sclerotized formation in the ventral plate, as well as abnormalities of the spiracle, anal groove, festoon, parma, and posteromedian groove. General anomalies comprised of asymmetries and gynandromorphism. Local anomalies were documented among H. dromedarii and H. rufipes, whereas general anomalies were documented only from H. dromedarii. The present work represents the first report of deuterogynander intrigue gynandromorphism in H. dromedarii, as well as the first report of morphological abnormalities in H. dromedarii and H. rufipes from Egypt.
Assuntos
Ixodidae , Infestações por Carrapato , Carrapatos , Animais , Camelus , Egito , Infestações por Carrapato/veterináriaRESUMO
Rhipicephalus are a species-diverse genus of ticks, mainly distributed in the Afrotropics with some species in the Palearctic and Oriental regions. Current taxonomic consensus comprise nine informal species groups/lineages based on immature morphology. This work integrates biogeographic, ecological and molecular lines of evidence to better understand Rhipicephalus evolution. Phylogenetic analysis based on four genes (12S, 16S, 28S-D2 and COI) recovered five distinct clades with nine descendant clades that are generally congruent with current taxonomy, with some exceptions. Historical biogeography is inferred from molecular divergence times, ancestral distribution areas, host-use and climate niches of four phylogenetically significant bioclimatic variables (isothermality, annual, seasonal and diurnal temperature range). Novel hosts enabled host-linked dispersal events into new environments, and ticks exploited new hosts through nested predator-prey connections in food webs. Diversification was further induced by climate niche partitioning along gradients in temperature range during off-host periods. Ancestral climate niche estimates corroborated dispersal events by indicating hypothetical ancestors moved into environments with different annual and seasonal temperature ranges along latitudinal gradients. Host size for immature and adult life stages was important for dispersal and subsequent diversification rates. Clades that utilise large, mobile hosts (ungulates and carnivores) early in development have wider geographic ranges but slower diversification rates, and those utilising small, less mobile hosts (rodents, lagomorphs and afroinsectivores) early in development have smaller ranges but higher diversification rates. These findings suggest diversification is driven by a complex set of factors linked to both host-associations (host size, ranges and mobility) and climate niche partitioning along annual and seasonal temperature range gradients that vary with latitude. Moreover, competitive interactions can reinforce these processes and drive speciation. Off-host periods facilitate adaptive radiation by enabling host switches along nested predator-prey connections in food webs, but at the cost of environmental exposure that partitions niches among dispersing progenitors, disrupting geneflow and driving diversification. As such, the evolution and ecological niches of Rhipicephalus are characterised by trade-offs between on- and off-host periods, and these trade-offs interact with nested predator-prey connections in food webs, host-use at different life stages, as well as gradients in annual and seasonal temperature ranges to drive adaptive radiation and speciation.
Assuntos
Cadeia Alimentar , Especiação Genética , Especificidade de Hospedeiro , Filogenia , Rhipicephalus/classificação , Rhipicephalus/genética , Temperatura , Animais , Ecossistema , Feminino , MasculinoRESUMO
The present report describes morphological anomalies in Rhipicephalus sanguineus s.s. collected from dogs between February 2017 and May 2019 in the steppic region of Djelfa and high plateau area of Bordj-Bou-Arreridj in Algeria. Out of 1043 ticks from 147 infested dogs, four adult ticks (0.38%), collected from four dogs, exhibited local morphological abnormalities. One male displayed ectromely of leg I left, and the other three specimens exhibited multiple associated anomalies in idiosomas and exoskeletons, festoons, stigmas (spiracles), as well as in adanal and accessory plates. This report provides additional exemplars of morphological abnormalities in tick populations of Africa, particularly North Africa.
Assuntos
Doenças do Cão , Ixodidae , Rhipicephalus sanguineus , Infestações por Carrapato , Argélia , Animais , Doenças do Cão/epidemiologia , Cães , Masculino , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/veterináriaRESUMO
Ticks will diminish productivity among farm animals and transmit zoonotic diseases. We conducted a study to identify tick species infesting slaughter bulls from Adama City and to screen them for tick-borne pathogens. In 2016, 291 ticks were collected from 37 bulls in Adama, which were ready for slaughter. Ticks were identified morphologically. Total genomic DNA was extracted from ticks and used to test for Rickettsia spp. with real-time PCR. Species identification was done by phylogenetic analysis using sequencing that targeted the 23S-5S intergenic spacer region and ompA genes. Four tick species from two genera, Amblyomma and Rhipicephalus, were identified. Amblyomma cohaerens was the dominant species (n = 241, 82.8%), followed by Amblyomma variegatum (n = 22, 7.5%), Rhipicephalus pulchellus (n = 19, 6.5%), and Rhipicephalus decoloratus (n = 9, 3.0%). Among all ticks, 32 (11%) were positive for Rickettsia spp. and 15 (5.2%) of these were identified as R. africae comprising at least two genetic clades, occurring in A. variegatum (n = 10) and A. cohaerens (n = 5). The remainder of Rickettsia-positive samples could not be amplified due to low DNA yield. Furthermore, another 15 (5.2%) samples carried other pathogenic bacteria: Ehrlichia ruminantium (n = 9; 3.1%) in A. cohaerens, Ehrlichia sp. (n = 3; 1%) in Rh. pulchellus and A. cohaerens, Anaplasma sp. (n = 1; 0.5%) in A. cohaerens, and Neoehrlichia mikurensis (n = 2; 0.7%) in A. cohaerens. All ticks were negative for Bartonella spp., Babesia spp., Theileria spp., and Hepatozoon spp. We reported for the first time E. ruminatium, N. mikurensis, Ehrlichia sp., and Anaplasma sp. in A. cohaerens. Medically and veterinarily important pathogens were mostly detected from A. variegatum and A. cohaerens. These data are relevant for a One-health approach for monitoring and prevention of tick-borne disease transmission.
Assuntos
Doenças dos Bovinos , Ixodidae , Rickettsia , Infestações por Carrapato , Doenças Transmitidas por Carrapatos , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Etiópia/epidemiologia , Masculino , Filogenia , Rickettsia/genética , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/veterinária , Doenças Transmitidas por Carrapatos/epidemiologia , Doenças Transmitidas por Carrapatos/veterináriaRESUMO
The present study aims to perform comparative genetic characterization for R. sanguineus s.l. infesting Algerian dogs living in steppe and high plateau regions based on mitochondrial 16S rRNA gene sequencing and phylogenetic analysis. In total, 1043 ticks were collected from 147 infested dogs, including 756 ticks from 124 dogs in Djelfa and 287 ticks from 23 dogs in Bordj-Bou-Arreridj. All ticks were morphologically identified as R. sanguineus s.l., and 87 specimens were randomly selected for molecular analysis. Sequences obtained from selected ticks clustered with sequences of R. sanguineus s.l. from France, Germany, Portugal, and Spain, all of which belong to R. sanguineus s.s. The occurrence of R. sanguineus s.s. in Algeria is an interesting result given that most R. sanguineus in Africa cluster among the tropical lineage. This finding should prompt further investigation by exhaustive studies across Algerian territory. Such data can be useful to understand the dispersal route of R. sanguineus s.s. from Europe to North Africa, or whether their occurrence in Algeria is a result of historical biogeography.
Assuntos
Genes Mitocondriais/genética , Filogenia , RNA Ribossômico 16S/genética , Rhipicephalus sanguineus/classificação , Rhipicephalus sanguineus/genética , Argélia , Animais , Doenças do Cão/parasitologia , Cães , Europa (Continente)RESUMO
In Uganda, the role of ticks in zoonotic disease transmission is not well described, partly, due to limited available information on tick diversity. This study aimed to identify the tick species that infest cattle. Between September and November 2017, ticks (n = 4362) were collected from 5 districts across Uganda (Kasese, Hoima, Gulu, Soroti, and Moroto) and identified morphologically at Uganda Virus Research Institute. Morphological and genetic validation was performed in Germany on representative identified specimens and on all unidentified ticks. Ticks were belonging to 15 species: 8 Rhipicephalus species (Rhipicephalus appendiculatus, Rhipicephalus evertsi evertsi, Rhipicephalus microplus, Rhipicephalus decoloratus, Rhipicephalus afranicus, Rhipicephalus pulchellus, Rhipicephalus simus, and Rhipicephalus sanguineus tropical lineage); 5 Amblyomma species (Amblyomma lepidum, Amblyomma variegatum, Amblyomma cohaerens, Amblyomma gemma, and Amblyomma paulopunctatum); and 2 Hyalomma species (Hyalomma rufipes and Hyalomma truncatum). The most common species were R. appendiculatus (51.8%), A. lepidum (21.0%), A. variegatum (14.3%), R. evertsi evertsi (8.2%), and R. decoloratus (2.4%). R. afranicus is a new species recently described in South Africa and we report its presence in Uganda for the first time. The sequences of R. afranicus were 2.4% divergent from those obtained in Southern Africa. We confirm the presence of the invasive R. microplus in two districts (Soroti and Gulu). Species diversity was highest in Moroto district (p = 0.004) and geographical predominance by specific ticks was observed (p = 0.001). The study expands the knowledge on tick fauna in Uganda and demonstrates that multiple tick species with potential to transmit several tick-borne diseases including zoonotic pathogens are infesting cattle.
Assuntos
Doenças dos Bovinos/parasitologia , Ixodidae/classificação , Infestações por Carrapato/veterinária , Animais , Biodiversidade , Bovinos , Ixodidae/anatomia & histologia , Ixodidae/genética , Infestações por Carrapato/parasitologia , UgandaRESUMO
Ticks are important parasites from economic and public health points of view because of their ability to reduce farm animals' productivity and transmit zoonotic diseases. We conducted this cross-sectional study between January and March 2016 and between March and April 2017 to identify tick species in West Darfur, Al-Jazeera, and the River Nile states in the Sudan and to investigate whether these ticks carry Rickettsia spp. and Crimean-Congo hemorrhagic fever (CCHF) virus. In total, 1593 ticks were collected from 207 animals and identified based on morphology or 16S rRNA gene and tested for Rickettsia spp. and CCHF virus either individually or as pools containing 2 to 10 pooled ticks using molecular methods. Overall, 14 tick species belonging to three genera, namely Amblyomma, Hyalomma, and Rhipicephalus, were identified. Hyalomma anatolicum and Rhipicephalus evertsi evertsi were the most frequent ticks. A total of 561 tests comprised of individual or pooled ticks were conducted and 13.7% (77/561) were positive for Rickettsia spp. which were mostly Rickettsia aeschlimannii and R. africae. The highest positivity was noticed among H. rufipes collected from cattle and camels in West Darfur. However, none of the screened Hyalomma ticks harbored CCHF viral RNA. These findings suggest that there might be a risk of zoonotic transmission of Rickettsia spp. by ticks but zoonotic transmission of CCHF virus is apparently doubtful. An in-depth and a country-wide epidemiological study is needed to better understand the dynamic of Rickettsia spp. and CCHF virus in the Sudan.
Assuntos
Vírus da Febre Hemorrágica da Crimeia-Congo/isolamento & purificação , Febre Hemorrágica da Crimeia/transmissão , Ixodidae/microbiologia , Infecções por Rickettsia/transmissão , Rickettsia/isolamento & purificação , Doenças Transmitidas por Carrapatos/microbiologia , Animais , Camelus , Bovinos , Estudos Transversais , Vírus da Febre Hemorrágica da Crimeia-Congo/genética , Parasitos/genética , RNA Ribossômico 16S/genética , Rickettsia/genética , Sudão , Zoonoses/transmissãoRESUMO
Ticks are obligate blood-sucking parasites of wild animals and transmit many zoonotic microorganisms that can spread to domesticated animals and then to humans. In Cameroon, little is known about tick diversity among wildlife, especially for animals which are hunted for human consumption. Therefore, this survey was undertaken to investigate tick and Rickettsia species diversity parasitizing the wild animals sold in bush meat markets in Cameroon. In total, 686 ticks were collected and identified to the species level based on morphology, and some were genetically analyzed using the 16S rRNA gene. Eighteen tick species belonging to five genera were identified: Amblyomma spp. (Amblyomma compressum, Amblyomma flavomaculatum, and Amblyomma variegatum), Haemaphysalis spp. (Haemaphysalis camicasi, Haemaphysalis houyi, Haemaphysalis leachi, and Haemaphysalis parmata), Hyalomma spp. (Hyalomma nitidum, Hyalomma rufipes, and Hyalomma truncatum), Ixodes spp. (Ixodes rasus and Ixodes moreli), and Rhipicephalus spp. (Rhipicephalus guilhoni, Rhipicephalus moucheti, Rhipicephalus muhsamae, Rhipicephalus microplus, Rhipicephalus camicasi, and Rhipicephalus linnaei). In terms of Rickettsia important for public health, two Rickettsia spp., namely Rickettsia aeschlimannii and Rickettsia africae, were detected in Hyalomma spp. and Amblyomma spp., respectively. Distinct tick-pathogen patterns were present for divergent sequences of R. africae associated with exclusively A. variegatum vectors (type strain) versus vectors comprising A. compressum, A. flavomaculatum, and A. variegatum. This suggests possible effects of vector species population dynamics on pathogen population circulation dynamics. Furthermore, Candidatus Rickettsia africaustralis was detected for the first time in Cameroon in I. rasus. This study highlights the high diversity of ticks among wildlife sold in bush meat markets in Cameroon.
RESUMO
Distinct life stages may experience different selection pressures influencing phenotypic evolution. Morphological evolution is also constrained by early phenotypes, since early development forms the phenotypic basis of later development. This work investigates evolutionary-developmental modification in three life stages and both sexes of 24 Rhipicephalus species using phylogenetic comparative methods for geometric morphometrics of basis capituli (basal mouthpart structure used for host attachment), and scutum or conscutum areas (proxy for overall body size). Findings indicate species using large hosts at early life stages have distinct basis capituli shapes, correlated with host size, enabling attachment to the tough skins of large hosts. Host-truncate species (one- and two-host) generally retain these adaptive features into later life stages, suggesting neoteny is linked to the evolution of host truncation. In contrast, species using small hosts at early life stages have lost these features. Developmental trajectories differ significantly between host-use strategies (niches), and correlate with distinct clades. In two-host and three-host species using large hosts at early life stages, developmental change is heterotopically accelerated (greater cell mass development) before the first off-host period where selection probably favours large individuals able to better resist dehydration when questing (waiting) for less abundant, less active hosts. In other species, development is heterotopically reduced (neotenic), possibly because dehydration risk is bypassed by prolonged host attachment (one-host species - heterotopic neoteny), or is allometrically repatterned possibly by using highly abundant and active hosts (three-host species using small hosts at early life stages - allometric repatterning). These findings highlight complex trade-offs between on- and off-host factors of free-living ectoparasite ecology, which mediate responses to diverse selection pressures varied by life stage and host-use strategy. It is proposed that these trade-offs shape evolutionary-developmental morphology and diversity of Rhipicephalus ticks.
Assuntos
Rhipicephalus , Animais , Desidratação , Ecologia , Feminino , Masculino , Filogenia , Rhipicephalus/genéticaRESUMO
Tick-borne diseases are recognized as a growing public health concern and cause significant issues in humans and animals by serving as dispersal agents of ticks and their associated pathogens. Birds contribute to the spread of ticks and tick-borne diseases, with migratory birds playing a role in regional dispersal. Only a few studies have been carried out in Germany so far to investigate tick fauna on birds and the pathogens they harbour. In 2017 and 2018, we collected ticks from a total of 358 birds in the northern region of the Federal State of Hesse, Germany. Most ticks were Ixodes ricinus larvae and nymphs (95.4%). However, two ornithophilic species were also collected: Ixodes frontalis (larvae, nymphs and females) and Ixodes arboricola (larvae and nymphs). Ticks were tested individually or in pools, depending on the tick life stage and species for each bird host, in order to detect tick-borne encephalitis (TBE) virus and Rickettsia spp. All samples tested negative for TBE virus. Of 684 investigated tick pools, 162 tested positive for Rickettsia spp. by screening PCR. Of these, 117 carried Rickettsia helvetica detected by specific real-time PCR. The samples which were negative in the R. helvetica PCR were further investigated using five targets (gltA, 16S, ompA IV, ompB, 23S-5S intergenic spacer region) using multi locus sequence typing and phylogenetic analysis. The obtained sequences showed strong phylogenetic relationship to Candidatus Rickettsia vini, which is most closely related to R. japonica and R. heilongjiangensis, and occur in I. arboricola. Three more sequences were determined as R. helvetica in I. ricinus and I. frontalis. This is the first detection of Ca. R. vini in Germany and the first 23S-5S data published for Ca. R. vini, a useful target for Rickettsia species identification.
Assuntos
Ixodes , Ixodidae , Rickettsia , Animais , Aves , Feminino , Alemanha/epidemiologia , Ixodes/microbiologia , Tipagem de Sequências Multilocus , Filogenia , Rickettsia/genéticaRESUMO
Epidemiology and distributions of canine tick-borne diseases as well as their veterinary and zoonotic significance are poorly understood in Algeria. The present study describes a molecular investigation of important tick-borne pathogens in Rhipicephalus sanguineus sensu stricto collected from domestic dogs in steppe and high plateau areas of central and eastern Algeria. In total, 1,043 ticks were collected from 147 dogs, including 756 ticks from 124 dogs in the steppe region of Djelfa and 287 ticks from 23 dogs in the high plateau area of Bordj Bou Arreridj. Ticks were divided into 384 pools (309 pools from Djelfa and 75 pools from Bordj Bou Arreridj) and tested for genomic materials of Crimean-Congo hemorrhagic fever virus (CCHFV) as well as DNA for Anaplasma phagocytophilum, Anaplasma platys, Ehrlichia canis, Rickettsia spp., Babesia spp., and Hepatozoon spp. using PCR, sequencing and phylogenetic analysis. Hepatozoon spp. was most prevalent, with 160 positive pools (41.7%), and 12 of these were sequenced and identified as Hepatozoon canis. Babesia spp. was detected in 50 samples (13.0%), of which 11 were sequenced and identified as Babesia vogeli. A. platys and E. canis were detected in 92 (24.0%) and 15 (3.9%) of tested samples, respectively. Rickettsia spp. were detected in 24 (6.3%) samples, including 11 samples identified as R. massiliae, 6 samples identified as R. conorii conorii, and 7 samples could not be identified to species level. All 384 pools tested negative for CCHFV and A. phagocytophilum. In addition to detection of R. conorii conorii, R. massiliae, and E. canis, the present study provides the first molecular data for occurrence of A. platys, B. vogeli, and H. canis in Rh. sanguineus s.s. infesting dogs in Algeria. Further large scale studies should be conducted to better understand the epidemiology, distributions, and importance of canine tick-borne pathogens in Algeria.
Assuntos
Babesia , Doenças do Cão , Eucoccidiida , Rhipicephalus sanguineus , Rickettsia , Doenças Transmitidas por Carrapatos , Argélia/epidemiologia , Animais , Babesia/genética , Doenças do Cão/epidemiologia , Doenças do Cão/microbiologia , Cães , Ehrlichia canis/genética , Filogenia , Rhipicephalus sanguineus/microbiologia , Rickettsia/genética , Doenças Transmitidas por Carrapatos/epidemiologia , Doenças Transmitidas por Carrapatos/microbiologia , Doenças Transmitidas por Carrapatos/veterináriaRESUMO
Seasonal migration of birds between breeding and wintering areas can facilitate the spread of tick species and tick-borne diseases. In this study, 151 birds representing 10 different bird species were captured on Ponza Island, an important migratory stopover off the western coast of Italy and screened for tick infestation. Ticks were collected and identified morphologically. Morphological identification was supported through sequencing a fragment of the 16S mitochondrial gene. In total, 16 captured birds carried ticks from four tick species: Hyalomma rufipes (n = 14), Amblyomma variegatum (n = 1), Amblyomma sp. (n = 1), and Ixodes ventalloi (n = 2). All specimens were either larvae (n = 2) or nymphs (n = 16). All ticks were investigated for tick-borne pathogens using published molecular methods. Rickettsia aeschlimannii was detected in six of the 14 collected H. rufipes ticks. Additionally, the singular A. variegatum nymph tested positive for R. africae. In all 14 H. rufipes specimens (2 larvae and 12 nymphs), Francisella-like endosymbionts were detected. Four H. rufipes ticks tested positive for Borrelia burgdorferi sensu lato in a screening PCR but did not produce sufficient amplicon amounts for species identification. All ticks tested negative for tick-borne encephalitis virus, Crimean-Congo hemorrhagic fever virus, Coxiella burnetii, Coxiella-like organisms, Babesia spp., and Theileria spp. This study confirms the role of migratory birds in the spread and establishment of both exotic tick species and tick-borne pathogens outside their endemic range.
Assuntos
Doenças das Aves/epidemiologia , Ixodidae/microbiologia , Ixodidae/parasitologia , Aves Canoras , Infestações por Carrapato/veterinária , Doenças Transmitidas por Carrapatos/veterinária , Animais , Bactérias/isolamento & purificação , Infecções Bacterianas/epidemiologia , Infecções Bacterianas/microbiologia , Infecções Bacterianas/veterinária , Doenças das Aves/microbiologia , Doenças das Aves/parasitologia , Incidência , Ilhas , Itália/epidemiologia , Ixodidae/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Larva/microbiologia , Larva/parasitologia , Ninfa/crescimento & desenvolvimento , Ninfa/microbiologia , Ninfa/parasitologia , Piroplasmida/isolamento & purificação , Prevalência , Infecções Protozoárias em Animais/epidemiologia , Infecções Protozoárias em Animais/parasitologia , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/parasitologia , Doenças Transmitidas por Carrapatos/epidemiologia , Doenças Transmitidas por Carrapatos/microbiologia , Doenças Transmitidas por Carrapatos/parasitologiaRESUMO
Rhipicephalus turanicus ticks are widely distributed across the Palearctic and Afrotropics. These two continental populations display differences in morphological characters that raise the question of a potential species boundary. However, the taxonomic status of these morphologically divergent lineages is uncertain because R. turanicus from Cyprus and Zambia have been shown to interbreed and produce fertile hybrids. We employ integrative taxonomy that considers data from mtDNA sequences (12S and 16S rDNA), geographic distribution, traditional (qualitative) morphology, as well as shape outlines of female spiracles and male adanal plates measured in a geometric morphometric framework (quantitative morphology) to resolve this taxonomic issue. Molecular lines of evidence (12S and 16S rDNA) support taxonomic separation between ticks sampled in the Afrotropics and the Palearctic. This is corroborated by qualitative and quantitative morphology. Within the Palearctic, two sub-lineages were recovered based on sequence data that loosely correspond to southern Europe and the Middle East/Asia. One new species, Rhipicephalus afranicus n. sp. is described from South Africa with a geographic distribution that extends into eastern Africa. This leaves R. turanicus sensu lato comprised of two lineages located in southern Europe and the Middle East/Asia. The type locality for R. turanicus is in Uzbekistan, thus the Middle East/Asia lineage is considered R. turanicus sensu stricto. Detailed descriptions are provided for R. afranicus n. sp. and R. turanicus sensu stricto together with high resolution images. Speciation is attributed to recent Sahara desert expansion that formed a natural barrier to dispersal approximately 5-7 million years ago. However, reproductive potential between these two species suggests that divergence time and mode of speciation were not sufficient for the development of reproductive isolation. We suggest speciation was complicated by divergence and population reintegration events driven by oscillating climatic conditions contributing to reticulate evolution and maintenance of compatibility between reproductive mechanisms. This study represents an integrative (iterative) approach to delimiting Rhipicephalus spp., and provides the first application of shape outlines for female spiracles and male adanal plates measured in a geometric morphometric framework, applied to testing species boundaries between ticks.
Assuntos
Filogenia , Rhipicephalus , Animais , Ásia , Europa (Continente) , Feminino , Masculino , Oriente Médio , Rhipicephalus/classificação , África do SulRESUMO
Ticks and tick-borne diseases (TBDs) have a major economic impact on animal production worldwide. In the present study, 2410 ticks were collected from January to August 2017 from livestock and other domestic animals in North Kordofan and Kassala, Sudan, for species identification and investigation of Rickettsia spp. and piroplasms, either individually or as pools containing up to 10 ticks by molecular methods. In total, 13 tick species were identified by morphology and 16S rDNA sequencing. The most frequent tick species were Hyalomma impeltatum (24.90%), Rhipicephalus evertsi evertsi (18.84%), Amblyomma lepidum (16.06%), and Rhipicephalus camicasi (12.49%). A pan-Rickettsia real-time PCR revealed an overall minimum infection rate (MIR) with Rickettsia spp. of 5.64% (136 positive tick pools/2410 total ticks). Rickettsia africae and Rickettsia aeschlimannii were the most frequently identified species by sequencing. Furthermore, the following highly pathogenic livestock parasites were detected: Theileria annulata, Theileria lestoquardi, Theileria equi, and Babesia caballi. The present study documented Rhipicephalus afranicus as well as Rickettsia conorii israelensis, Rickettsia massiliae, and Babesia pecorum for the first time in Sudan. These findings are significant for the animal production sector as well as in terms of One Health, as the detected Rickettsia spp. can cause serious illness in humans.
RESUMO
Morphological abnormalities in ticks seem to be rare phenomena in nature, and are underreported in Africa. In this article, we describe general and local anomalies in two Amblyomma lepidum females and one Rhipicephalus decoloratus female collected from cattle in Moroto and Kasese districts, Uganda. One A. lepidum specimen displayed metagynander gynandromorphism with the presence of both male and female features in the same organism. The second A. lepidum female showed slight asymmetry and lacked a genital aperture. The R. decoloratus displayed multiple anomalies that included asymmetry on the right side in association with ectromely, chitinous formations and constrictions on the left side. This article presents the first report of metagynander gynandromorphism, as well as genital aperture absence which is not linked to gynandromorphism, in A. lepidum collected from cattle.
Assuntos
Ixodidae/anatomia & histologia , Animais , Bovinos , Doenças dos Bovinos/parasitologia , Feminino , Rhipicephalus/anatomia & histologia , Infestações por Carrapato/parasitologia , Infestações por Carrapato/veterinária , UgandaRESUMO
The systematics of the genera and subgenera within the soft tick family Argasidae is not adequately resolved. Different classification schemes, reflecting diverse schools of scientific thought that elevated or downgraded groups to genera or subgenera, have been proposed. In the most recent classification scheme, Argas and Ornithodoros are paraphyletic and the placement of various subgenera remains uncertain because molecular data are lacking. Thus, reclassification of the Argasidae is required. This will enable an understanding of soft tick systematics within an evolutionary context. This study addressed that knowledge gap using mitochondrial genome and nuclear (18S and 28S ribosomal RNA) sequence data for representatives of the subgenera Alectorobius, Argas, Chiropterargas, Ogadenus, Ornamentum, Ornithodoros, Navis (subgen. nov.), Pavlovskyella, Persicargas, Proknekalia, Reticulinasus and Secretargas, from the Afrotropical, Nearctic and Palearctic regions. Hard tick species (Ixodidae) and a new representative of Nuttalliella namaqua (Nuttalliellidae), were also sequenced with a total of 83 whole mitochondrial genomes, 18S rRNA and 28S rRNA genes generated. The study confirmed the utility of next-generation sequencing to retrieve systematic markers. Paraphyly of Argas and Ornithodoros was resolved by systematic analysis and a new species list is proposed. This corresponds broadly with the morphological cladistic analysis of Klompen and Oliver (1993). Estimation of divergence times using molecular dating allowed dissection of phylogeographic patterns for argasid evolution. The discovery of cryptic species in the subgenera Chiropterargas, Ogadenus and Ornithodoros, suggests that cryptic speciation is common within the Argasidae. Cryptic speciation has implications for past biological studies of soft ticks. These are discussed in particular for the Ornithodoros (Ornithodoros) moubata and Ornithodoros (Ornithodoros) savignyi groups.
Assuntos
Argasidae/classificação , Especiação Genética , Genoma Mitocondrial/genética , Animais , Argas/classificação , Argas/genética , Argasidae/genética , Classificação , Código de Barras de DNA Taxonômico , DNA Ribossômico/química , DNA Ribossômico/genética , Sequenciamento de Nucleotídeos em Larga Escala , Ornithodoros/classificação , Ornithodoros/genética , Filogenia , RNA Ribossômico 18S/genética , RNA Ribossômico 28S/genética , Análise de Sequência de DNARESUMO
Afrotropical Ornithodoros (Ornithodoros) ticks are revised based on qualitative morphology of females and nymphs, as well as tarsus I shape outlines of females measured in a geometric morphometric framework. These lines of evidence corroborate lineages based on 16S rRNA nucleotide sequence data. Four previously unrecognized species are described, along with a revived nomen nudum that was previously considered a synonym. Afrotropical Ornithodoros (Ornithodoros) now comprise ten species. Ornithodoros moubata and Ornithodoros porcinus are separated from three other species in southern Africa (Ornithodoros compactus, Ornithodoros phacochoerusn. sp., Ornithodoros waterbergensisn. sp.), with O. porcinus restricted to central east Africa. Known species boundaries for Ornithodoros apertus and O. compactus are supported. Ornithodoros savignyi are separated from three other species in South Africa and Namibia, with O. savignyi restricted to north Africa. Neumann's Ornithodoros pavimentosusnom. rev. are resurrected from synonymy as a species that occur in Bushmanland, Namaqualand and Namibia, while Ornithodoros kalahariensisn. sp. occur in Kalahari thornveld, and Ornithodoros noorsveldensisn. sp. occur in Noorsveld thicket of South Africa. Detailed descriptions are given for each species along with high resolution images and point map distributions. Support is provided for speciation driven by riverine barriers, Pliocene uplift and differential arid tolerance. Exaggerated tarsus I shape in the O. savignyi group suggests adaptation to fossorial habits and soil type. Conversely, reduced tarsus I shape in the O. moubata group is suggested as an evolutionary consequence of the life history change from soil to warthog burrows. This study represents an integrative (iterative) approach to delimiting Afrotropical Ornithodoros (Ornithodoros) species, and provides the first application of tarsus I shape outlines in a geometric morphometric framework for testing species boundaries.
Assuntos
Ornithodoros/anatomia & histologia , Ornithodoros/classificação , África Oriental/epidemiologia , África Austral/epidemiologia , Animais , Feminino , Humanos , Ninfa/anatomia & histologia , Ninfa/fisiologia , Ornithodoros/genética , Ornithodoros/fisiologia , Filogenia , RNA Ribossômico 16S/genética , África do Sul/epidemiologia , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/parasitologia , Infestações por Carrapato/veterinária , Vertebrados/parasitologiaRESUMO
Afrotropical Psychopsidae Handlirsch are revised based on morphology. Molecular data from a previous study enables updated taxonomy in this revision, and morphology corroborates phylogenetic divergences. The genus Silveira was found to form a lineage separate from Zygophlebiinae based on molecular data and six morphological synapomorphies. In this revision, Silveira is moved to a new subfamily, leaving only Cabralis and Zygophlebius in Zygophlebiinae. Two new species of Cabralis are described. Afrotropical Psychopsidae now comprise ten species, three genera and two subfamilies. A dichotomous key to these taxa is provided, along with a web link to a fully-illustrated and interactive multi-access LUCID v3 key. High resolution images and distribution maps are provided for all species.