RESUMEN
Rickettsiales are obligate intracellular bacteria that need vertebrates and arthropods to maintain their life cycles. Some species of the genera Anaplasma, Ehrlichia, and Rickettsia are transmitted by ticks to both animals and humans and can cause mild to severe and even fatal cases. In the Americas, there is substantial data on rickettsial agents, encompassing both clinical cases and the detection of these agents in ticks, but in Ecuador, the information about them remains poorly understood. Therefore, the objective of this study was to detect molecularly rickettsial agents in Amblyomma maculatum ticks in both parasitic and free-living phases collected from domestic animals and pasture in five localities across three coastal provinces of Ecuador. Rickettsia parkeri, Candidatus Rickettsia andeanae, and Ehrlichia sp. were recorded in A. maculatum for the first time in Ecuador. These records were made in a region where antibodies to the Spotted Fever Rickettsia Group were detected in humans. Additional studies are needed to characterize Ehrlichia sp. at a specific level. Furthermore, recognizing the specific Rickettsiales species circulating in the ticks and the hosts within a region is crucial for assessing potential contact risks.
Asunto(s)
Amblyomma , Rickettsiales , Amblyomma/microbiología , Ecuador , Rickettsiales/clasificación , Rickettsiales/genética , Rickettsiales/aislamiento & purificación , Animales Domésticos/parasitología , Animales , ADN Bacteriano/genética , FilogeniaRESUMEN
Canine tick-borne diseases, such as babesiosis, rangeliosis, hepatozoonosis, anaplasmosis and ehrlichiosis, are of veterinarian relevance, causing mild or severe clinical cases that can lead to the death of the dog. The aim of this study was detecting tick-borne protozoan and rickettsial infections in dogs with anemia and/or thrombocytopenia in Uruguay. A total of 803 domestic dogs were evaluated, and 10% were found positive (detected by PCR) at least for one hemoparasite. Sequence analysis confirmed the presence of four hemoprotozoan species: Rangelia vitalii, Babesia vogeli, Hepatozoon canis and Hepatozoon americanum, and the rickettsial Anaplasma platys. The most detected hemoparasite was R. vitalii, followed by H. canis and A. platys. This is the first report of B. vogeli in Uruguay and the second report of H. americanum in dogs from South America. The results highlight the importance for veterinarians to include hemoparasitic diseases in their differential diagnosis of agents causing anemia and thrombocytopenia.
Asunto(s)
Anemia , Enfermedades de los Perros , Piroplasmida , Trombocitopenia , Animales , Uruguay , Perros , Enfermedades de los Perros/parasitología , Enfermedades de los Perros/diagnóstico , Enfermedades de los Perros/epidemiología , Trombocitopenia/veterinaria , Trombocitopenia/parasitología , Anemia/veterinaria , Anemia/parasitología , Piroplasmida/aislamiento & purificación , Piroplasmida/genética , Femenino , Anaplasmataceae/aislamiento & purificación , Anaplasmataceae/genética , Masculino , Infecciones por Anaplasmataceae/veterinaria , Infecciones por Anaplasmataceae/epidemiología , Anaplasma/aislamiento & purificación , Anaplasma/genética , Babesiosis/parasitología , Babesiosis/diagnóstico , Coccidiosis/veterinaria , Coccidiosis/parasitología , Eucoccidiida/aislamiento & purificación , Eucoccidiida/genética , Enfermedades por Picaduras de Garrapatas/veterinaria , Enfermedades por Picaduras de Garrapatas/parasitología , Enfermedades por Picaduras de Garrapatas/microbiología , Enfermedades por Picaduras de Garrapatas/epidemiología , Babesia/aislamiento & purificación , Infecciones Protozoarias en Animales/parasitología , Infecciones Protozoarias en Animales/epidemiología , Reacción en Cadena de la Polimerasa/veterinariaRESUMEN
During a molecular screening of rickettsial, borrelial and protozoal agents in ticks from rural areas of Panama, we detected DNA of Rickettsia amblyommatis in four Amblyomma mixtum collected from horses in a locality in Los Santos province. Ehrlichia minasensis and Anaplasma marginale were identified from three and two Rhipicephalus microplus, respectively, collected on cows from Chiriqui province. No DNA from other tick-borne agents was found. These results increase the information of R. amblyommatis and A. marginale in Panama, and also mark the first record of E. minasensis in Central America.
Asunto(s)
Rhipicephalus , Femenino , Animales , Bovinos , Caballos , Rhipicephalus/microbiología , Ehrlichia/genética , Panamá/epidemiología , América CentralRESUMEN
Babesia spp. are tick-borne protozoans that involve birds and mammals in their transmission cycles and cause babesiosis, a severe hemolytic malaria-like disease. Opossums of the genus Didelphis are recognized hosts of tick-borne pathogens. Therefore, exploring tick-borne agents in Didelphis species is important to understand the circulation of pathogens in areas where opossums occur. In this study, we targeted Anaplasmataceae, Babesia, Borrelia and Hepatozoon DNA in ticks, blood and organ samples collected from three hunted Didelphis marsupialis specimens in eastern Guatemala. While the samples were negative for Hepatozoon and bacterial DNA, sequences of Babesia 18S rDNA, cox1 and cytb genes were retrieved from two opossums. Ticks collected on the animals included Amblyomma parvum and an undetermined Ornithodoros sp. The Babesia sp. detected in this study (Babesia sp. THB1-2) clusters phylogenetically within the "Western Babesia group", which includes pathogenic species such as Babesia conradae, Babesia duncani, and Babesia negevi. Our results represent the first record of a Babesia sp. in Guatemala and highlight the importance of D. marsupialis as potential spreaders of ticks and pathogens in Central America.
Asunto(s)
Babesia , Babesiosis , Didelphis , Eucoccidiida , Animales , Guatemala/epidemiología , Babesia/genética , América Central , Babesiosis/epidemiologíaRESUMEN
Soft ticks (Argasidae) of the Pavlovskyella Pospelova-Shtrom subgenus are important vectors of relapsing fever spirochetes, which are agents of disease globally. South American representatives of the Pavlovskyella subgenus include 3 species: Ornithodoros (Pavlovskyella) brasiliensis Aragão, Ornithodoros (Pavlovskyella) furcosus Neumann, and Ornithodoros (Pavlovskyella) rostratus Aragão. Here, we describe a fourth species based on morphological and mitogenomic evidence of ticks collected in burrows of unknown hosts in central Chile. The larva of the new species separates from other South American soft ticks by the following combination of characters: 13 pairs of dorsolateral setae, dorsal plate hexagonal, hypostome blunt with denticles from apex almost to the base. Adults of this new species lack cheeks, possess a dorsoventral groove, and have humps, similar to O. (P.) brasiliensis; however, they lack bulging structures on the flanks of idiosoma. Moreover, females and males differ from O. (P.) rostratus by having 3 humps instead of spurs in tarsi I and from O. (P.) furcosus because of their smaller size and thinner anterior lip of the genital aperture in females. The phylogenetic analysis performed with mitogenomes of the Argasidae family depicts the new Pavlovskyella species from Chile in a monophyletic clade with other South American species in the subgenus, confirming a regional group.
Asunto(s)
Ácaros y Garrapatas , Argasidae , Ornithodoros , Femenino , Masculino , Animales , Argasidae/genética , Chile , Filogenia , Ornithodoros/genéticaRESUMEN
The aim of this work is to report the first detection of Procyon cancrivorus naturally co-infected with Hepatozoon sp. cf. H. procyonis and a novel Anaplasma strain from South America and potential vector tick species associated. On August 30, 2016, a specimen of P. cancrivorus was found dead on the route in Chaco province, Argentina. A tick and a blood sample by cardiac puncture was collected from the specimen. DNA was extracted from blood sample and the tick was morphological identity as a female of Amblyomma ovale. Molecular detection of Anaplasmataceae family and Hepatozoon spp. agents was performed targeting two different loci: 16 S rRNA and 18 S rRNA gene. The phylogenetic analyses show that the Anaplasma sp. strain detected in P. cancrivorus in this study is similar to Anaplasma sp. strains previously detected in Nasua nasua and A. ovale from Brazil. Furthermore, Hepatozoon sp. of the H. procyonis group was amplified that is phylogenetically closely related to H. procyonis reported in N. nasua from Brazil. Since it was not exactly the same as the latter, it was decided to name at Hepatozoon sp. cf. H. procyonis. It is possible that, this potential new species of Anaplasma would be specific for Procyonidae family and there are two species of Hepatozoon linked to this family in South America. These results added to other published studies suggest that A. ovale could be a potential vector both for the new potential strain of Anaplasma and for the Hepatazoon sp. of the H. procyonis group.
Asunto(s)
Anaplasmataceae , Apicomplexa , Carnívoros , Procyonidae , Garrapatas , Femenino , Animales , Mapaches , Anaplasma/genética , Rickettsiales , Argentina , Filogenia , BrasilRESUMEN
The aim of this work was to describe the tick community associated to domestic mammals in rural areas from the Yungas lower montane forest of Argentina. The circulation of tick-borne pathogens was also analyzed. Samples of ticks parasitizing cattle, horses, sheep and dogs were carried out in different seasons, and questing ticks were collected from vegetation and analyzed to detect the presence of Rickettsia, Ehrlichia, Borrelia and Babesia by a battery of different PCRs. The structure of the tick communities was analyzed through the Chao1 species richness estimator, the Shannon-Wiener index and the Horn index of community similarity. Eight tick species were collected in the study area: Amblyomma sculptum, Rhipicephalus microplus, Amblyomma hadanii, Dermacentor nitens, Amblyomma ovale, Haemaphysalis juxtakochi, Ixodes pararicinus and Rhipicephalus sanguineus sensu stricto. However, A. sculptum was by far the dominant species in the tick assemblages analyzed, and this was reflected in the low diversity values obtained. Dermacentor nitens, A. sculptum and R. microplus were the three species associated to horses. The predominance of A. sculptum was also observed in the tick samples obtained from dogs, even on two tick species, namely A. ovale and R. sanguineus s.s., which have dogs as the principal domestic host. Rhipicephalus microplus and A. sculptum were the most abundant ticks on cattle, while few specimens of I. pararicinus, A. hadanii and D. nitens were found on bovines. Dermacentor nitens ticks were found to be infected with B. caballi, which indicate the circulation of this pathogen of horses in the Yungas area. The detection of a strain of Borrelia sp. belonging to the B. burgdorferi s.l. complex in I. pararicinus is consistent with previous findings made in Argentina, but the public health relevance of this vector-microorganism association is far from being similar to that occurs in the northern hemisphere because there are practically no records of these tick species parasitizing humans in South America. The tick community of rural areas of the Yungas lower montane forest is composed by species which are potential vectors of pathogenic microorganism with veterinary and public health importance, circulating in a human-wildlife-livestock interface.
Asunto(s)
Borrelia , Ixodes , Rhipicephalus , Humanos , Caballos , Bovinos , Animales , Perros , Ovinos , Argentina/epidemiología , Mamíferos , Amblyomma , BosquesRESUMEN
The aim of this study was to report tick infestations on wild birds from four Phytogeographic Provinces of Argentina. A total of 1085 birds was captured (124 species, 97 genera, 29 families and 13 orders), and ticks were collected from 265 birds (48 species, 40 genera and five orders). A total of 1469 ticks (1102 larvae, 363 nymphs and 4 females) belonging to 15 tick species (Amblyomma calcaratum, Amblyomma dubitatum, Amblyomma nodosum, Amblyomma ovale, Amblyomma parvum, Amblyomma sculptum, Amblyomma tigrinum, Amblyomma triste, Haemaphysalis juxtakochi, Haemaphysalis leporispalustris, Ixodes auritulus sensu lato, Ixodes pararicinus, Ixodes silvanus, Ixodes sp. cf. I. affinis and Ornithodoros sp. cf. O. mimon). Eighty-one new associations between bird species and stages of tick species are detected. The families Thamnophilidae, Turdidae, Thraupidae, Passerellidae, Furnariidae and Troglodytidae were the most prevalent. According to the Phytogeographic Provinces involved in this study, the prevalence of infection for each of them in birds was: (1) Chaco: 28.2% (11 tick species); (2) Yungas: 22.0% (8 tick species); (3) Espinal: 11.1% (2 tick species); and (4) Pampa: 3.9% (1 tick species). This study provided information on the diversity of tick species that parasitize wild birds, the variability of the specific tick-bird associations between the different Phytogeographic Provinces and the relevance of some families of birds as hosts of different tick species.
Asunto(s)
Argasidae , Ixodes , Ixodidae , Passeriformes , Pájaros Cantores , Infestaciones por Garrapatas , Animales , Femenino , Argentina/epidemiología , Animales Salvajes , Infestaciones por Garrapatas/epidemiología , Infestaciones por Garrapatas/veterinaria , AmblyommaRESUMEN
The major surface protein 1a (MSP1a) gene has been used to characterize Anaplasma marginale genetic diversity. This pathogen causes significant productivity and economic losses to the cattle industry. The objective of the present study was to report the first characterization of A. marginale genetic diversity in Uruguay based on MSP1a genotypes and their putative relationship with Rhipicephalus microplus. This cross-sectional study was conducted between 2016 and 2020. The study included whole blood samples from clinical cases of bovine anaplasmosis obtained from 30 outbreaks located in six Uruguay territorial departments. Diagnosis was performed using Giemsa-stained smears and confirmed by nested Polymerase Chance Reaction (nPCR) targeting the A. marginale major surface protein 5 gene. The genetic diversity of A. marginale strains was characterized by analyzing the microsatellite and tandem repeats of MSP1a. Based on the microsatellite structure, four genotypes were identified. Genotype E was the most prevalent. Analysis of MSP1a tandem repeats showed 28 different strains from the combination of 31 repeats, with τ-10-15 and α-ß-ß-ß-Γ being the most common. Repeats Γ, ß, α, and γ were associated with the absence of R. microplus with statistical significance (p < 0.05). Molecular observations showed that 46.7% of the strains identified in our samples lacked the ability to bind to tick cells; therefore, they were probably transmitted by other vectors. Strain genetic diversity provides valuable information for understanding the epidemiological behavior of A. marginale and could contribute to the development of effective vaccines for the control of this disease.
RESUMEN
Bovine babesiosis and anaplasmosis cause important economic losses in livestock production. In Uruguay, the main aetiological agents of bovine babesiosis and anaplasmosis are Babesia bovis, B. bigemina and Anaplasma marginale. The aim of this work was to describe the outbreaks of bovine babesiosis and anaplasmosis in northern Uruguay between 2016 and 2018. Convenience sampling was carried out. We worked with blood and organ samples from bovines with clinical signs and autopsy findings compatible with babesiosis and anaplasmosis. A total of 140 presumptive outbreaks were studied. Epidemiological information such as place, date of occurrence, age, number of sick and dead animals, clinical signs, autopsy findings, the presence of ticks and health management that involved injectables were registered. The diagnoses were carried out by blood and organ smears stained with Giemsa and confirmed by multiplex PCR. There were 83 (59.2%) positive outbreaks, comprising 35 (42.2%) A. marginale, 19 (22.9%) B. bigemina, 18 (21.7%) B. bovis and 11 (13.2%) mixed infections (Babesia spp. + A. marginale). Cows were the most commonly affected category. The clinical signs and autopsy findings with a significant association (p ≤ 0.05) were anaemia, pale mucous membranes, fever, jaundice, ataxia and aggressiveness, splenomegaly, and orange discolouration of the liver. Babesiosis had a seasonal occurrence, mainly in autumn, while anaplasmosis cases were recorded throughout the year. The use of injectable agents was associated with A. marginale transmission. This work contributes updated information about epidemiological and clinical patterns of bovine babesiosis and anaplasmosis in northern Uruguay, which is important for implementing preventive measures and control.
Asunto(s)
Anaplasmosis , Babesiosis , Enfermedades de los Bovinos , Anaplasmosis/diagnóstico , Animales , Babesiosis/diagnóstico , Bovinos , Enfermedades de los Bovinos/diagnóstico , Brotes de Enfermedades/veterinaria , Femenino , Uruguay/epidemiologíaRESUMEN
The aim of this study was to determine the infection with Rickettsiales in ticks and birds from the main protected urban area of Buenos Aires City (Argentina). One Amblyomma aureolatum (0.2%) and one Ixodes auritulus (0.1%) were positive by PCR targeting Rickettsia 23S-5S rRNA intergenic spacer. Phylogenetic analysis shows to findings in A. aureolatum are closely to Rickettsia bellii and for I. auritulus are related to 'Candidatus Rickettsia mendelii'. One I. auritulus (0.1%) and three A. aureolatum (0.6%) were positive by PCR for a fragment of the 16S rRNA gene of the Anaplasmataceae family. The sequences obtained from A. aureolatum were phylogenetically related to Midichloriaceae endosymbionts. The sequence from I. auritulus s.l. had 100% identity with Ehrlichia sp. Magellanica from Chile and two genotypes of Ehrlichia sp. from Uruguay. The results of our study show that Rickettsia and Ehrlichia are present in ticks in the main protected urban area of Buenos Aires City.
Asunto(s)
Ixodes , Rickettsia , Animales , Argentina , Ehrlichia/genética , Ixodes/genética , Filogenia , ARN Ribosómico 16S/genética , Rickettsia/genéticaRESUMEN
Ticks are blood-sucking arthropods that parasitize most groups of terrestrial or semiaquatic vertebrates. Humans are accidental hosts to the ticks; however, in humans the ticks can cause damages varying from simple irritation to severe allergies, toxicosis, paralysis, and the transmission of pathogens, some of which can be fatal. Central America represents a narrow isthmus between North and South America and is considered a biodiversity hotspot. The importance of tick-borne diseases in this region is manifested by fatal outbreaks caused by Rickettsia rickettsii, severe and mild cases of other rickettsioses, ehrlichiosis, and tick-borne relapsing fevers, in addition to cases paralysis and strong allergic reactions. Even so, this information is scarce in most countries of this region, and there are no epidemiological data. In this article we present a review of the ticks that parasitize humans in Central America, covering data from the 19th Century to the present day. Of nearly 80 tick species reported in Central America, 28 species are reported on humans. This list includes species that thrive within homes, grazing areas and, to a lesser extent, in wild environments, both in lowland and high mountain forests. The most important genus in this region is Amblyomma, followed by Rhipicephalus and Ornithodoros, and to a lesser extent Haemaphysalis, Ixodes and Dermacentor. These data provide information on the tick species most commonly associated with humans in Central America, and highlight the potential for tick-borne diseases in wild, rural and urban regions.
RESUMEN
INTRODUCTION: Ixodes tropicalis is a little-known tick species reported parasitizing wild rodents only in Colombia and Perú. OBJECTIVE: To report a case of I. tropicalis infesting a human in the south of the metropolitan area of the Valle de Aburrá, Antioquia, Colombia, and to report the molecular detection of Rickettsia bellii in this species. MATERIALS AND METHODS: The tick was identified using a morphological key and sequencing of tick mitochondrial 16S rRNA. Additionally, bacterial and protozoa pathogens were evaluated using PCR for the detection of Rickettsia spp., family Anaplasmataceae, Borrelia spp., and piroplasmid. RESULTS: We identified the tick as an I. tropicalis female according to Kohls, 1956, description and to partial 16S rRNA sequences showing a minimum of 5% divergencies compared to Ixodes sequences. We also detected the gltA gene of R. bellii in the tick with 99.87% of identity. CONCLUSION: This is the first report in Colombia of a species of the Ixodes genus parasitizing a human and the first report of the detection of R. bellii in this tick species.
Introducción. Ixodes tropicalis es una especie de garrapata poco conocida que se había reportado parasitando únicamente roedores silvestres en Colombia y Perú. Objetivo. Reportar un caso de infestación por I. tropicalis en un ser humano del sur del área metropolitana del Valle de Aburrá (Antioquia) y reportar la detección molecular de Rickettsia bellii en esta especie. Materiales y métodos. La garrapata se identificó usando claves morfológicas y mediante la secuenciación de su gen 16S ARNr mitocondrial. Además, se evaluó la presencia de agentes patógenos bacterianos y protozoos usando PCR para la detección de Rickettsia spp., la familia Anaplasmataceae, Borrelia spp. y piroplásmidos. Resultados. La garrapata se identificó como una hembra de I. tropicalis, según la descripción de Kohls, 1956, y la secuencia parcial del gen 16S ARNr, la cual mostró una divergencia de mínimo 5 % en la comparación con las secuencias de Ixodes. Además, se detectó el gen gltA de R. bellii en esta garrapata con una similitud del 99,87 %. Conclusión. Este es el primer reporte en Colombia de una especie del género Ixodes parasitando a un humano y el primer reporte de la detección de R. bellii en esta especie de garrapata.
Asunto(s)
Ixodes , Infestaciones por Garrapatas , Animales , Colombia , Femenino , Humanos , ARN Ribosómico 16S/genética , Rickettsia , Infestaciones por Garrapatas/veterinariaRESUMEN
Rangelia vitalii is a protozoan parasite that causes a hemorrhagic and hemolytic disease in dogs known as rangeliosis. Current reports of the disease are concentrated in the southern and southeastern regions of Brazil, as well as in Uruguay, Argentina, and Paraguay, and mainly concern domestic dogs. South American wild canids, such as the crab-eating fox (Cerdocyon thous), the pampas fox (Lycalopex gymnocercus), and the maned wolf (Chrysocyon brachyurus) may also be affected, although existing reports are restricted to Brazil. The present study aimed to detect R. vitalii parasitism in the Uruguayan wild fox population. DNA extracted from the blood and/or spleen samples of road-killed C. thous and L. gymnocercus found in northern Uruguay were subjected to polymerase chain reaction (PCR) to amplify a 551-bp fragment of the Rangelia 18S rRNA gene. A total of 62 wild canids, including 38 C. thous and 24L. gymnocercus, were analyzed. Five crab-eating fox samples (13.2%) were positive for R. vitalii, with 99.5-100% identity between the sequences. All samples from pampas fox tested negative for R. vitalii. When compared with the R. vitalii sequences available in GenBank, a similarity of 98.9-100% was revealed. Molecular analysis results suggest that R. vitalii is circulating in the crab-eating fox population in Uruguay; however, its veterinary relevance for these foxes remains unknown.
Asunto(s)
Canidae , Piroplasmida/aislamiento & purificación , Infecciones Protozoarias en Animales/epidemiología , Animales , Femenino , Masculino , Prevalencia , Infecciones Protozoarias en Animales/parasitología , Uruguay/epidemiologíaRESUMEN
Abstract | Introduction: Ixodes tropicalis is a little-known tick species reported parasitizing wild rodents only in Colombia and Perú. Objective: To report a case of I. tropicalis infesting a human in the south of the metropolitan area of the Valle de Aburrá, Antioquia, Colombia, and to report the molecular detection of Rickettsia bellii in this species. Materials and methods: The tick was identified using a morphological key and sequencing of tick mitochondrial 16S rRNA. Additionally, bacterial and protozoa pathogens were evaluated using PCR for the detection of Rickettsia spp., family Anaplasmataceae, Borrelia spp., and piroplasmid. Results: We identified the tick as an I. tropicalis female according to Kohls, 1956, description and to partial 16S rRNA sequences showing a minimum of 5% divergencies compAred to Ixodes sequences. We also detected the gltA gene of R. bellii in the tick with 99.87% of identity. Conclusion: This is the first report in Colombia of a species of the Ixodes genus parasitizing a human and the first report of the detection of R. bellii in this tick species.
Resumen | Introducción. Ixodes tropicalis es una especie de garrapata poco conocida que se había reportado parasitando únicamente roedores silvestres en Colombia y Perú. Objetivo. Reportar un caso de infestación por I. tropicalis en un ser humano del sur del área metropolitana del Valle de Aburrá (Antioquia) y reportar la detección molecular de Rickettsia bellii en esta especie. Materiales y métodos. La garrapata se identificó usando claves morfológicas y mediante la secuenciación de su gen 16S ARNr mitocondrial. Además, se evaluó la presencia de agentes patógenos bacterianos y protozoos usando PCR para la detección de Rickettsia spp., la familia Anaplasmataceae, Borrelia spp. y piroplásmidos. Resultados. La garrapata se identificó como una hembra de I. tropicalis, según la descripción de Kohls, 1956, y la secuencia parcial del gen 16S ARNr, la cual mostró una divergencia de mínimo 5 % en la compAración con las secuencias de Ixodes. Además, se detectó el gen gltA de R. bellii en esta garrapata con una similitud del 99,87 %. Conclusión. Este es el primer reporte en Colombia de una especie del género Ixodes parasitando a un humano y el primer reporte de la detección de R. bellii en esta especie de garrapata.
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Rickettsia , Ixodes , Bacterias , Vectores de EnfermedadesRESUMEN
Ornithodoros tabajara n. sp. is described from laboratory-reared larvae and adult specimens collected in the Brazilian Caatinga. This new species shares the ecological niche with Ornithodoros rietcorreai and is likely associated with colonial rodents of genus Kerodon. However, O. tabajara n. sp. is morphologically easy to distinguish from O. rietcorreai and other Neotropical Ornithodoros by a unique combination of characters: larva with 17 pairs of dorsal setae (seven anterolateral, three central and seven posterolateral), sub-oval dorsal plate, hypostome blunt apically with dentition formula 2/2 along its extension, only one pair of posthypostomal setae, six pairs of sternal setae, posteromedian setae absent, and leave-shaped anal valves; alive adults with whitish islands of mammillae symmetrically distributed on dorsum (not visible in ethanol-preserved specimens), and median disk merging with posteromedian file. A phylogenetic analysis performed with mitochondrial 16S rDNA sequences points O. tabajara n. sp. as O. rietcorreai's sister taxon, which rises the hypothesis of sympatric speciation.
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Clasificación , Ornithodoros/clasificación , Animales , Argasidae/anatomía & histología , Argasidae/clasificación , Argasidae/genética , Brasil , Ecosistema , Bosques , Especiación Genética , Ornithodoros/anatomía & histología , Ornithodoros/genética , Filogenia , ARN Ribosómico 16S/genéticaRESUMEN
Based on tick specimens collected recently in Mexico, Nicaragua, Panama and Brazil, we provide morphological descriptions of the nymph and adults of Ornithodoros clarki Jones & Clifford, 1972 from the first three countries, and the larva and nymph of Ornithodoros rondoniensis (Labruna, Terassini, Camargo, Brandão, Ribeiro & Estrada-Peña, 2008) from Brazil. Also, an analysis of mitochondrial 16S rDNA sequences was performed to analyze the phylogenetic relationships of these tick species. Adults and nymphs of O. clarki and O. rondoniensis are unique among the Argasidae family by presenting exceptionally large spiracular plates with small goblets, and an integument with smooth polygonal mammillae. However, these two species are morphologically distinct based on specific patterns of coxal folds, idiosomal mammillae and pilosity, and female genital flap. In contrast, the larvae of O. clarki and O. rondoniensis are morphologically identical, except for a general larger size of the former species; this slight difference is corroborated by Principal Component Analysis (PCA) by using 40 morphometric variables. Phylogenetic analyses including 16S rDNA partial sequences of different Ornithodoros taxa from Central and South America indicate that O. rondoniensis from Brazil diverges from O. clarki from Mexico, Nicaragua and Panama. However, phylogenetic distance separating both alleged species is similar or slightly lower than the distances depicted for conspecific populations of a few other Ornithodoros species. Nonetheless, our primary criterion to maintain O. rondoniensis as a valid species is because its adult and nymphal stages do present distinct morphological traits that easily distinguish these postlarval stages from O. clarki.
Asunto(s)
Ornithodoros , Filogenia , Américas , Animales , Larva/anatomía & histología , Ninfa/anatomía & histología , Ornithodoros/anatomía & histología , Ornithodoros/clasificación , Ornithodoros/genética , ARN Ribosómico 16S/genética , Especificidad de la EspecieRESUMEN
Ehrlichia are small intracellular Gram-negative bacteria transmitted by ticks. These microorganisms cause ehrlichiosis, a complex of life-threatening emerging zoonoses and diseases of global veterinary relevance. The aim of this study was to investigate the presence of Ehrlichia in free-living Ixodes auritulus collected in Uruguay. Ticks were collected from vegetation in five localities from the southeast and northeast of the country between 2014 and 2017. Detection of Ehrlichia DNA was performed in pools of adults or nymphs grouped according to the collection site and date. A total of 1,548 I. auritulus ticks were collected in four of the five locations sampled. Fragments of three loci (16S rRNA, dsb and groEL) were obtained by PCR, and phylogenies inferred using Bayesian inference analysis for each gene independently. DNA of Ehrlichia spp. was found in 15 out of 42 tick pools. Based on the topology of the phylogenetic trees, our sequences represent two novel genotypes for the genus named as Ehrlichia sp. Serrana and Ehrlichia sp. Laguna Negra. Both genotypes were closely related to Ehrlichia sp. Magellanica, a species detected in Ixodes uriae and Magellanic penguins. Considering that all stages of I. auritulus and I. uriae are parasites of birds, their phylogenetic relationships, and common eco-epidemiological profiles, it is reasonable to state that these genotypes of Ehrlichia spp. may represent a natural group likely associated with birds. Our results constitute the first characterization of Ehrlichia spp. in Uruguay. Future studies on birds reported as hosts for I. auritulus are needed to further understand the epidemiological cycles of both Ehrlichia genotypes in the country. Finally, I. auritulus does not feed on humans, so the two Ehrlichia species reported herein might have no implications in human health.
RESUMEN
The first molecular screening for Rickettsia, Anaplasma, Ehrlichia, Borrelia, Babesia and Hepatozoon was carried out in questing Ixodes cf. boliviensis and Ixodes tapirus from Talamanca Mountains, Panama, using specific primers, sequencing and phylogeny. Phylogenetic analyses for the microorganisms in Ixodes cf. boliviensis confirmed the presence of Rickettsia sp. strain IbR/CRC endosymbiont (26/27 ticks), three genotypes of the Borrelia burgdorferi (sensu lato) complex (4/27 ticks), Babesia odocoilei (1/27 ticks), and Hepatozoon sp. (2/27 ticks), tentatively designated Hepatozoon sp. strain Chiriquensis. Phylogenetic analyses for the microorganisms in I. tapirus revealed an undescribed Rickettsia sp., tentatively designated Rickettsia sp. strain Itapirus LQ (6/6 ticks), and Anaplasma phagocytophilum (2/6 ticks). To the best of our knowledge, this is the first report of B. burgdorferi (s.l.) complex, A. phagocytophilum, B. odocoilei, and Hepatozoon sp. in Ixodes ticks from Central America, and also the first detection of Rickettsia spp. in Ixodes species in Panama. In light of the importance of these findings, further studies are needed focusing on the role of I. tapirus and I. cf. boliviensis as vectors, and the vertebrates acting as reservoirs.
RESUMEN
Females, nymphs, and larvae of Ixodes silvanus n. sp. collected from birds and from the vegetation in northwestern Argentina (Yungas Phytogeographic Province) are described herein. The new species belongs to the subgenus Trichotoixodes (Acari: Ixodidae). The female is diagnosed by a combination of the following characters: scutum with setae moderately long and more numerous in central field, fewer and moderately long setae on lateral fields, and inconspicuous setae in anterior field; basis capituli subtriangular dorsally; porose areas large and irregular in shape, lacking distinct margins; auriculae with straight edges diverging posterolaterally and ending with small blunt processes; hypostome narrow and pointed with dental formula 4/4 in the anterior third, then 3/3 and 2/2 near the base; coxae I with two spurs, sub-equal in size, internal slightly slimmer than external. The nymph is diagnosed by notum with numerous and long setae, ventral surface covered by numerous whitish setae, scutum with short scapulae and few and shallow punctations, setae on scutum few, short and irregularly distributed, basis capituli sub-triangular dorsally with posterior margin straight, cornua large and directed postero-laterally, auriculae large and projected laterally, lateral margin of basis capituli above auriculae with a lateral and triangular projection, hypostome pointed with dental formula 3/3 in the anterior third and then 2/2, and coxa I with two short, sub-equal, triangular spurs. The diagnostic characters of the larva are: basis capituli dorsally sub-triangular with lateral angles acute and posterior margin straight, auriculae as large triangular lateral projections, hypostome with apex bluntly pointed and dental formula 3/3 in the anterior third and then 2/2, coxa I with two short, sub-equal, triangular spurs, and pattern of dorsal and ventral body setae. This new species is phylogenetically related to Ixodes brunneus, Ixodes turdus and Ixodes frontalis, and the principal hosts for all its parasitic stages are birds.