RESUMO
The pivotal role of amphibians in food webs and their value as indicators of disequilibrium in ecosystem health have long been recognized by wildlife biologists. However, massive pathogen-induced declines in global amphibian populations reported during the last 30 years served to alert the scientific community that knowledge of amphibian disease ecology, including parasitic and vector-borne conditions, was and remains incipient. Herein, we report the detection of a Rickettsia bacterium infecting larvae of the argasid tick Ornithodoros faccinii, collected from the toad Rhinella ornata, in Southeastern Brazil. Fragments of the genes 16S rDNA, gltA, htrA, sca1, sca4, and ompB were amplified by polymerase chain reaction (PCR), but the sequence encoding the ompA antigen was not detected. Nucleotide sequencing and multi-locus (gltA, htrA, sca1, and sca4) phylogenetic analyses characterized the bacterium, designated Rickettsia sp. strain Itinguçú, as a novel member of the spotted fever group (SFG) of the Rickettsia, closely related to the Rickettsia massiliae and to a lesser extent the Rickettsia helvetica subgroups. The apparent absence of the ompA protein together with limited levels of nucleotide (90.5 %) and amino acid (82-83 %) sequence identity, relative to the ompB gene of other species in the R. massiliae subgroup, were unusual features that may reflect adaptation to selective pressures exerted by the tick and/or amphibian immune systems. The ompB sequence was exploited to develop a low-cost method for differential identification of Rickettsia sp. strain Itinguçú, based on restriction fragment length polymorphism analysis of amplicons (PCR-RFLP). The characterization of this novel bacterium provided an unprecedented record of infection by an SFG Rickettsia in a member of the family Argasidae infesting a cold-blooded animal and raised the number of tick-associated Rickettsia reported in Brazil to sixteen. Moreover, it highlighted the value of and the requirement for continued and extended surveillance of wildlife as potential sources of emerging tick-borne pathogens.
Assuntos
Bufonidae/parasitologia , Ornithodoros/microbiologia , Rickettsia/isolamento & purificação , Animais , Brasil , Larva/crescimento & desenvolvimento , Larva/microbiologia , Ornithodoros/crescimento & desenvolvimento , Filogenia , Rickettsia/classificaçãoRESUMO
Ornithodoros cerradoensis n. sp. is described from field-collected and laboratory reared nymphs, males, females, and larvae parasitizing the rodents Cavia aperea and Thrichomys sp. in the Brazilian Savannah. This new species is morphologically and genetically related with the Ornithodoros talaje group and can be separated from other Neotropical species using the following combination of characters: larva with 18 pairs of setae on dorsum (seven anterolateral, four central and seven posterolateral), hypostome with median dentition 2/2; adults provided with large mammillae; dorsal disks surrounded by bulked marginal ridges delimiting barely pebbled areas; three disks in the anterolateral file, and median disk not merging with the posteromedian file. Feeding assays in the laboratory demonstrated that (1) larvae of O. cerradoensis are slow-feeders (â¼6 days), (2) first nymphal instar (N1) molts to second instar (N2) without feeding, and (3) N2 and third nymphal instar (N3) engorge rapidly (minutes). With the exception of Ornithodoros hasei nymphs that depict flattened bodies, O. cerradoensis N1, N2, and N3 highly resemble homologous instars of other species in O. talaje sensu lato, therefore are not suitable for morphological comparisons within the group. In addition to morphological signature of larvae and adults that separate this new species; results of cross-mating attempts between O. cerradoensis and Ornithodoros guaporensis a morphologically and phylogenetically closely related species that also parasitizes rodents in the Brazilian Savannah; a Principal Component Analysis using larval characters; and a phylogenetic analysis using mitochondrial markers, support O. cerradoensis as an independent lineage within the Ornithodorinae.
Assuntos
Interações Hospedeiro-Parasita , Ornithodoros/classificação , Roedores/parasitologia , Animais , Brasil , DNA Ribossômico/análise , Feminino , Pradaria , Cobaias/parasitologia , Larva/crescimento & desenvolvimento , Larva/ultraestrutura , Masculino , Microscopia Eletrônica de Varredura/veterinária , Ninfa/crescimento & desenvolvimento , Ninfa/ultraestrutura , Ornithodoros/crescimento & desenvolvimento , Ornithodoros/ultraestrutura , Filogenia , RNA Ribossômico 16S/análiseRESUMO
Larvae of Ornithodoros knoxjonesi collected at five localities in three countries were studied using morphological and molecular methods to confirm this species' taxonomic validity. The larva of O. knoxjonesi is characterized as having 14 pairs of dorsal setae, eight pairs of ventral setae, plus a posteromedian seta; an elongate dorsal plate, tapered anteriorly; and a hypostome that is narrower near its midlength, with posteriorly projecting denticles. Although the larvae of O. knoxjonesi and Ornithodoros peropteryx are morphologically quite similar, the larva of O. knoxjonesi is characterized as having dorsal setae that are wider at the tip than at the base, while in O. peropteryx these setae are narrower at the tip than at the base; moreover, the dorsal setae are shorter in O. knoxjonesi (Al 0.037-0.065; Pl 0.035-0.059) than in O. peropteryx (Al 0.120-0.132; Pl 0.080-0.096). These species also differ in that O. knoxjonesi possesses only the Al seta on tarsus I, whereas O. peropteryx has both Al and Pl setae. And while both species have two setae on coxae I-III, in O. knoxjonesi the anterior seta is tapering and smooth and the posterior is fringed, while both setae are fringed in O. peropteryx. At the molecular level, based on a maximum likelihood analysis using approximately 400 bp of the mitochondrial 16S rDNA gene, O. knoxjonesi appears as an independent lineage, separated from O. peropteryx by a genetic distance of 16.28 %. Balantiopteryx plicata is a common host of O. knoxjonesi; however, in this work we report Pteronotus personatus and Pteronotus gymnonotus as new hosts of this tick species.
Assuntos
Distribuição Animal , Quirópteros/parasitologia , Ornithodoros/classificação , Ornithodoros/fisiologia , Animais , Costa Rica , DNA Ribossômico/análise , Larva/classificação , Larva/genética , Larva/crescimento & desenvolvimento , Larva/fisiologia , México , Nicarágua , Ornithodoros/genética , Ornithodoros/crescimento & desenvolvimento , FilogeniaRESUMO
A new argasid (Argasidae) tick is herein described based on morphology and molecular data obtained from larvae parasitizing Octodon degus and from ticks collected inside burrows in northern Chile. Unfed laboratory-reared larvae were mounted in slides for morphometrical and morphological analyses. Larvae of Ornithodoros octodontus n. sp. share morphological traits with Ornithodoros quilinensis and Ornithodoros xerophylus, two species associated with rodents in the Argentinean Chaco. However, a longer hypostome with two rows of 21 and 22 denticles each one, and conspicuous leaf-shaped anal plates separate O. octodontus. While nymphal stages of O. octodontus lack cheeks and possess a micromammillated dorsal integument, adults have cheeks and exhibit markedly irregular mammillae along their dorsal surface. Phylogenetic analyses of neotropical Argasidae based on mitochondrial 16S rDNA sequences point that O. octodontus forms a monophyletic group with O. xerophylus and an unidentified Ornithodoros sp. from Bolivia, all of them associated with burrow-dweller rodents. Ornithodoros aragaoi and Ornithodoros davisi, two rare species collected once only in the Peruvian Andean Plateau during 1955 are morphologically closely related with adults and nymphs of O. octodontus. Biological observations of O. octodontus revealed autogenic females. For the moment, subgeneric classification of this new species depends on further biological studies. The fauna of ticks occurring in Chile is now represented by 22 species, 11 belonging to the Argasidae family.
Assuntos
Octodon , Ornithodoros/classificação , Doenças dos Roedores/parasitologia , Infestações por Carrapato/veterinária , Animais , Chile , Feminino , Larva/anatomia & histologia , Larva/classificação , Larva/crescimento & desenvolvimento , Larva/ultraestrutura , Masculino , Microscopia Eletrônica de Varredura/veterinária , Ninfa/anatomia & histologia , Ninfa/classificação , Ninfa/crescimento & desenvolvimento , Ninfa/ultraestrutura , Ornithodoros/anatomia & histologia , Ornithodoros/crescimento & desenvolvimento , Ornithodoros/ultraestrutura , Infestações por Carrapato/parasitologiaRESUMO
Ornithodoros fonsecai is an argasid tick that is endemic to Brazil and has been described in the municipality of Bonito, state of Mato Grosso do Sul. Some specimens of this species were found in a cave in the municipality of Nobres, state of Mato Grosso. The specific identification of this population was confirmed by means of morphology and molecular biology. The mitochondrial 16S rDNA partial sequence of this species from Nobres has been deposited in GenBank (MK158949). The objective of this study was to elucidate the biology of O. fonsecai from Nobres, and to report autogeny in this tick population. Along three laboratory generations was observed molting of first nymphal instar to the second instar without feeding, a typical behavior of species included in the subgenus Alectorobius. The first generation (F1) presented five nymphal instars (N1 to N5), and most of adults emerged through molting of N5. The last nymphal instar of second generation (F2) was N4, but most of adults emerged from N3. In the third generation (F3) the last nymphal instar was N5, with most of the adults emerging from N4. In F2, some females (nâ¯=â¯20) originated from N3 began laying eggs without a blood meal. It was observed that those N3 fed twice before they molted to autogenic females. However, autogenic behavior occurred in relation to third generation females (F3) with specimens originating from N4 (nâ¯=â¯12) that were fed only once as nymphs. This behavior has already been reported as obligatory for the genera Otobius and Antricola, while it is facultative for one species of genus Argas and for four species of genus Ornithodoros. However, the present report provides the first record of facultative autogeny for a species of Ornithodoros in Brazil.
Assuntos
Características de História de Vida , Ornithodoros/fisiologia , Animais , Brasil , DNA Mitocondrial/análise , DNA Ribossômico/análise , Feminino , Larva/genética , Larva/crescimento & desenvolvimento , Larva/fisiologia , Masculino , Ninfa/genética , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia , Ornithodoros/genética , Ornithodoros/crescimento & desenvolvimento , Filogenia , ReproduçãoRESUMO
A new tick species of the genus Ornithodoros (Acari: Argasidae) was described from larvae collected on the toad Rhinella arenarum in a locality from Argentina belonging to the Monte Biogeographic Province. Ornithodoros montensis n. sp. was described based on morphological traits and sequences of the mitochondrial 16S rRNA gene. The diagnostic characters for this species are a combination of idiosoma oval, dorsal plate pyriform with posterior margin slightly concave, dorsal surface with 17 pairs of setae (7 anterolateral, 4 to 5 central and 5 to 6 posterolateral), ventral surface with 6 pairs of setae and 1 pair on anal valves, three pairs of sternal setae, postcoxal setae absent, and hypostome pointed apically with dental formula 3/3 in the anterior half and 2/2 posteriorly almost to base. Phylogenetic analysis of 16S rDNA sequences and a principal component analysis based on morphometric characters provided additional support to the description of O. montensis as an independent lineage within the genus Ornithodoros. Larvae of O. montensis are phylogenetically closely related to O. puertoricensis, O. rioplatensis, O. talaje s.s., O. guaporensis, O. hasei and O. atacamensis, all of them belonging to the "O. talaje group".
Assuntos
Bufonidae/parasitologia , Interações Hospedeiro-Parasita , Ornithodoros/classificação , Animais , Argentina , Larva/anatomia & histologia , Larva/classificação , Larva/genética , Ornithodoros/anatomia & histologia , Ornithodoros/genética , Ornithodoros/crescimento & desenvolvimento , RNA Ribossômico 16S/análiseRESUMO
Ornithodoros rostratus is a South American argasid tick which importance relies on its itchy bite and potential as disease vector. They feed on a wide variety of hosts and secrete different molecules in their saliva and intestinal content that counteract host defences and help to accommodate and metabolize the relatively large quantity of blood upon feeding. The present work describes the transcriptome profile of salivary gland (SG) and midgut (MG) of O. rostratus using Illumina sequencing. A total of 8,031 contigs were assembled and assigned to different functional classes. Secreted proteins were the most abundant in the SG and accounted for ~67% of all expressed transcripts with contigs with identity to lipocalins and acid tail proteins being the most representative. On the other hand, immunity genes were upregulated in MG with a predominance of defensins and lysozymes. Only 10 transcripts in SG and 8 in MG represented ~30% of all RNA expressed in each tissue and one single contig (the acid tail protein ORN-9707) represented ~7% of all expressed contigs in SG. Results highlight the functional difference of each organ and identified the most expressed classes and contigs of O. rostratus SG and MG.
Assuntos
Proteínas de Artrópodes/metabolismo , Ornithodoros/metabolismo , Proteoma/análise , RNA-Seq/métodos , Glândulas Salivares/metabolismo , Proteínas e Peptídeos Salivares/metabolismo , Transcriptoma , Animais , Proteínas de Artrópodes/genética , Biologia Computacional , Evolução Molecular , Ornithodoros/genética , Ornithodoros/crescimento & desenvolvimento , Filogenia , Proteínas e Peptídeos Salivares/genéticaRESUMO
In this study, we examine the current pattern of tick diversity and host use in French Guiana, South America, from 97 sampling localities encompassing peri-urban, rural and natural habitats. We collected 3395 ticks, including 1485 specimens from 45 vertebrate species (humans, domestic and wild animals) and 1910 questing specimens from vegetation. Morphological examinations identified 22 species belonging to six genera: Amblyomma (16 species), Rhipicephalus (two species), Ixodes (one species), Dermacentor (one species), Haemaphysalis (one species), Ornithodoros (one species). To facilitate future identification, we produced a bank of pictures of different stages for all these species. Taxonomic identification was then confirmed by molecular characterization of two mitochondrial genes, cytochrome c oxidase CO1 and 16S rDNA. Eleven of the 22 reported species were collected on humans, six on domestic animals and 12 on wild animals. The most widespread tick species collected were A. cajennense sensu stricto and, to a lesser extent, A. oblongoguttatum; both of these species were frequently found on humans. We used these results to discuss the tick-associated risks for human and animal health in French Guiana.
Assuntos
Distribuição Animal , Biodiversidade , Interações Hospedeiro-Parasita , Ixodidae/fisiologia , Ornithodoros/fisiologia , Infestações por Carrapato/veterinária , Animais , Animais Domésticos , Animais Selvagens , Proteínas de Artrópodes/análise , Complexo IV da Cadeia de Transporte de Elétrons/análise , Feminino , Guiana Francesa , Humanos , Ixodidae/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Larva/fisiologia , Masculino , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia , Ornithodoros/crescimento & desenvolvimento , RNA Ribossômico 16S/análise , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/parasitologiaRESUMO
We report tick infestations and rickettsial detection in ticks infesting free-living wild mammals (Monodelphis domestica, Tolypeutes tricinctus, Thrichomys inermis and Kerodon rupestris) captured in the Caatinga ecoregion of Bahia state, northeastern Brazil, during September to December 2016. Overall, 117 ticks (61 larvae, 25 nymphs, 25 males, 6 females) belonging to two genera, and at least three species were collected: Amblyomma auricularium, Amblyomma parvum, Amblyomma sp., Ornithodoros rietcorreai and an unidentified Ornithodoros sp. We provide new host records to the rodent T. inermis parasitized by larva and nymphs of A. auricularium and to the marsupial M. domestica infested by larvae of A. auricularium. Furthermore, we describe new tick-host association for larvae of O. rietcorreai on the rodents K. rupestris and T. inermis. Concerning tick-Rickettsia associations, we detected Rickettsia amblyommatis and an uncharacterized species of Rickettsia belonging to the spotted fever group (SFG) in both A. auricularium and A. parvum. Additionally, 'Candidatus Rickettsia andeanae' was detected in A. parvum as well.
Assuntos
Tatus , Gambás , Rickettsia/isolamento & purificação , Doenças dos Roedores/parasitologia , Infestações por Carrapato/veterinária , Carrapatos/microbiologia , Carrapatos/fisiologia , Animais , Brasil , Interações Hospedeiro-Parasita , Ixodidae/crescimento & desenvolvimento , Ixodidae/microbiologia , Ixodidae/fisiologia , Larva/crescimento & desenvolvimento , Larva/microbiologia , Larva/fisiologia , Ninfa/crescimento & desenvolvimento , Ninfa/microbiologia , Ninfa/fisiologia , Ornithodoros/crescimento & desenvolvimento , Ornithodoros/microbiologia , Ornithodoros/fisiologia , Infestações por Carrapato/parasitologia , Carrapatos/crescimento & desenvolvimentoRESUMO
In Brazil, at least 14 species of soft ticks (Argasidae) are associated with bats. While Ornithodoros hasei seems to be abundant among foliage-roosting bats, other groups of ticks are found exclusively inside caves. In this paper, noteworthy records of soft ticks infesting bats are documented in new localities from Bahia, Pernambuco, Piauí, and Rondônia states. Out of 201 bats examined, 25 were infested by 152 ticks belonging to seven taxa: Ornithodoros cavernicolous, O. hasei, Ornithodoros marinkellei, Ornithodoros cf. fonsecai, Ornithodoros cf. clarki, Antricola sp., and Nothoaspis amazoniensis. These findings provide new insights into the geographical distribution and host association of soft ticks occurring in the Neotropical region. Remarkably, morphological and biological observations about O. hasei are inferred based on the examination of on-host-collected first stage nymphs.
Assuntos
Distribuição Animal , Argasidae/fisiologia , Quirópteros , Interações Hospedeiro-Parasita , Infestações por Carrapato/veterinária , Animais , Argasidae/anatomia & histologia , Argasidae/crescimento & desenvolvimento , Brasil/epidemiologia , Larva/anatomia & histologia , Larva/crescimento & desenvolvimento , Larva/fisiologia , Ninfa/anatomia & histologia , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia , Ornithodoros/anatomia & histologia , Ornithodoros/crescimento & desenvolvimento , Ornithodoros/fisiologia , Prevalência , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/parasitologiaRESUMO
Hepatozoon species are vector-borne pathogens that infect domestic and wild animals. Marsupials of the species Didelphis albiventris are adapted to urban and peri-urban areas and act as reservoir hosts for several parasites. The present study evaluated the occurrence of infection by Hepatozoon species in synantropic D. albiventris from Botucatu, São Paulo, Brazil. Blood samples and ectoparasites from 19 D. albiventris were collected from urban and peri-urban areas. Hepatozoon spp. detection was performed by microscopy and molecular analysis. One opossum was positive for Hepatozoon spp. in microscopy analysis and PCR, while another animal was positive only in PCR. The obtained sequences were 100% identical to Hepatozoon canis. Six species of ticks and two species of fleas were detected on D. albiventris. This is the first report of H. canis in synantropic D. albiventris. In Brazil, H. canis transmission among dog populations is not well established, which highlights the importance of investigating the role that opossums might play in the epidemiology of this protozoan.
Assuntos
Coccidiose/veterinária , Didelphis , Eucoccidiida/isolamento & purificação , Infestações por Pulgas/veterinária , Infestações por Carrapato/veterinária , Animais , Brasil/epidemiologia , Coccidiose/epidemiologia , Coccidiose/parasitologia , Ctenocephalides/classificação , Eucoccidiida/classificação , Eucoccidiida/genética , Infestações por Pulgas/epidemiologia , Infestações por Pulgas/parasitologia , Ixodidae/classificação , Ixodidae/crescimento & desenvolvimento , Larva/classificação , Larva/crescimento & desenvolvimento , Ninfa/classificação , Ninfa/crescimento & desenvolvimento , Ornithodoros/classificação , Ornithodoros/crescimento & desenvolvimento , Filogenia , Análise de Sequência de DNA , Sifonápteros/classificação , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/parasitologiaRESUMO
In this study, we present a morphological description of immature and adult specimens of Ornithodoros saraivai n.sp., a tick associated with the frog Cycloramphus boraceiensis (Cycloramphidae) at São Sebastião island, located in the São Paulo state seaboard, Brazil. While larvae of O. saraivai are ecologically related to Ornithodoros faccinii, another soft tick associated with cycloramphids, the combination of 7 sternal pairs, 16 dorsal pairs, a pyriform dorsal plate and a partially toothed hypostome constitute unique characters of the O. saraivai larvae. One undetermined nymphal instar and adults of O. saraivai are similar to mature specimens of the Ornithodoros talaje species group; however, the O. saraivai specimens can be recognized by the presence of a robust bean-shaped spiracle with a large spiracular plate and more than two long seta in palpal article I. Identical partial sequences of the mitochondrial 16S rDNA gene confirmed the identity for all collected stages and for two cohorts of laboratory-reared larvae of O. saraivai. A Bayesian and Maximum Parsimony inferred phylogenetic trees supportthe position of O. saraivai in a clade with O. faccinii, suggesting the existence of an Ornithodoros lineage that evolved in association with amphibians...
Assuntos
Animais , Anfíbios/classificação , Anfíbios/crescimento & desenvolvimento , Ornithodoros/anatomia & histologia , Ornithodoros/classificação , Ornithodoros/crescimento & desenvolvimento , Ornithodoros/genéticaRESUMO
Rickettsiae are intracellular bacteria commonly associated with hematophagous arthropods. Most of them have been described in hard ticks, but some have been found in soft ticks. Here we report the detection and isolation of a new Rickettsia from Ornithodoros knoxjonesi larvae collected from Balantiopteryx plicata (Emballonuridae) in Nicoya, Costa Rica. Two ticks were processed to detect Rickettsia spp. genes gltA, ompA, ompB, and htrA by PCR. Part of the macerate was also inoculated into Vero E6 and C6/36 cell lines, and cells were evaluated by Giménez stain, indirect immunofluorescence assay (IFA), and PCR. Both ticks were positive by PCR and rickettsial growth was successful in Vero E6 cells. Amplification and sequencing of near full length rrs, gltA, sca4 genes, and fragments of ompA and ompB showed that the Rickettsia sp. was different from described species. The highest homologies were with 'Candidatus Rickettsia wissemanii' and Rickettsia peacockii: 99.70% (1321/1325) with both sequences for rrs, 99.58% (1172/1177) and 99.76% (1246/1249) for gltA, 99.26% with both sequences (2948/2970 and 2957/2979) for sca4, 98.78% (485/491) and 98.39% (2069/2115) for ompA, and 98.58 (1453/1474) and 98.92% (1459/1475) for ompB; respectively. Bat blood, spleen, liver, and lung samples analyzed for Rickettsia detection were negative. Results demonstrate that the Rickettsia isolated from O. knoxjonesi is probably an undescribed species that belongs to the spotted fever group, for which 'Candidatus Rickettsia nicoyana' is proposed. Considering that B. plicata inhabits areas where contact with humans may occur and that human parasitism by Ornithodoros has been reported in the country, it will be important to continue with the characterization of this species and its pathogenic potential.
Assuntos
Quirópteros/microbiologia , Quirópteros/parasitologia , Ornithodoros/microbiologia , Rickettsia/classificação , Animais , Proteínas de Bactérias/genética , Costa Rica , Larva/crescimento & desenvolvimento , Larva/microbiologia , Ornithodoros/crescimento & desenvolvimento , Filogenia , Rickettsia/genética , Rickettsia/isolamento & purificação , Análise de Sequência de DNARESUMO
The presence of ticks inside human constructions was evaluated in two localities from Colon province (Charco La Piedra and Espinar) and one from Panama province (Ancon, City of Panama). In two of houses, eight people from Charco La Piedra and one from Ancón reported "insect bites," which produced blisters for several weeks. The investigation resulted in the collection of argasid ticks, which were identified by morphology and sequencing the 16s ribosomal RNA gene, and later evaluated for the presence of relapsing fever Borrelia DNA. All ticks were identified as Ornithodoros puertoricensis. While spirochetal DNA was not detected by PCR in the ticks, our report highlights the potential for relapsing fever borreliosis in rural and urban localities in Panama.
Assuntos
Ornithodoros/fisiologia , Infestações por Carrapato/parasitologia , Distribuição Animal , Animais , Feminino , Humanos , Larva/classificação , Larva/crescimento & desenvolvimento , Larva/microbiologia , Larva/fisiologia , Masculino , Ninfa/classificação , Ninfa/crescimento & desenvolvimento , Ninfa/microbiologia , Ninfa/fisiologia , Ornithodoros/classificação , Ornithodoros/crescimento & desenvolvimento , Ornithodoros/microbiologia , PanamáRESUMO
Ticks associated with bats have been poorly documented in the Neotropical Zoogeographical Region. In this study, a total of 1028 bats were sampled for tick infestations in the southern portion of the Brazilian Pantanal. A total of 368 ticks, morphologically identified as Ornithodoros hasei (n = 364) and O. mimon (n = 4), were collected from the following bat species: Artibeus planirostris, Platyrrhinus lineatus, Phyllostomus hastatus, Mimon crenulatum and Noctilio albiventris. Morphological identification of O. hasei was confirmed by molecular analysis. Regarding the most abundant bat species, only 40 (6.2%) out of 650 A. planirostris were infested by O. hasei, with a mean intensity of 7.2 ticks per infested bat, or a mean abundance of 0.44 ticks per sampled bat. Noteworthy, one single P. hastatus was infested by 55 O. hasei larvae, in contrast to the 2.5-7.2 range of mean intensity values for the whole study. As a complement to the present study, a total of 8 museum bat specimens (6 Noctilio albiventris and 2 N. leporinus), collected in the northern region of Pantanal, were examined for tick infestations. These bats contained 176 ticks, which were all morphologically identified as O. hasei larvae. Mean intensity of infestation was 22, with a range of 1-46 ticks per infested bat. Our results suggest that A. planirostris might play an important role in the natural life cycle of O. hasei in the Pantanal.
Assuntos
Quirópteros , Ornithodoros/fisiologia , Infestações por Carrapato/veterinária , Animais , Brasil/epidemiologia , Feminino , Larva/fisiologia , Masculino , Ornithodoros/crescimento & desenvolvimento , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/parasitologiaRESUMO
Ornithodoros rostratus Aragão is an argasid tick found in Bolivia, Paraguay, Argentina and Brazil. Only limited studies about O. rostratus have been conducted and several aspects of their life cycle differ among studies or remain unexplored. In order to better elucidate the biology of O. rostratus, the present work describes its life cycle when feeding on mice under laboratory conditions. To complete their life cycle on mice, O. rostratus goes through a larval stage, 3-6 nymphal instars (nymph 1-6) and adult male and female. Adults can be originated from nymph 3-6. Nymphs 4 with higher weight after feeding tend to originate adults. Adults originated from early instars tended to be lighter. Females tended to be heavier than males. Larvae needed on average 2.7 days to complete their blood meal whereas other instars ranged from 17.3 to 78.3 min. The capacity to ingest blood was higher in larvae and females in comparison to males. The preecdysis period ranged from 5 to 12.5 days. After one blood meal, females remain on average 15.2 ± 5.8 days laying 276.8 ± 137.2.9 eggs. Females originated from nymph 4 had similar oviposition time, egg incubation and conversion ingested blood/number of eggs produced, but presented lower initial weigh and weigh gain, generating fewer eggs. Our results added novel information on O. rostratus biology and was discussed considering the variability of argasid populations and in context with the differences about their life cycle described in previous works.
Assuntos
Estágios do Ciclo de Vida , Ornithodoros/fisiologia , Animais , Comportamento Alimentar , Feminino , Masculino , Camundongos , Ornithodoros/crescimento & desenvolvimento , OviposiçãoRESUMO
Two new species of the genus Ornithodoros were described from larvae collected in Argentina and Chile. Ornithodoros xerophylus n. sp. was described from specimens collected on the small rodent Graomys centralis in Argentina. The diagnostic characters for this species are a combination of dorsal plate slightly oval with a length of approximately 250 µm, 16 pairs of dorsal setae, hypostome with apex rounded and dental formula 2/2 in most rows, 3/3 apically, and capsule of the Haller's organ oval in shape without reticulations. Larvae of Ornithodoros lahillei n. sp. were collected on the reptiles Philodryas chamissonis and Callopistes maculatus in Chile. The diagnostic characters for O. lahillei are a combination of dorsal plate subtriangular with margins corrugated and posterior margin convex, dorsal surface with 14 pairs of setae, absence of postcoxal setae, and hypostome with apex pointed and dental formula 3/3 in anterior third and 2/2 in the middle and basal portion. Phylogenetic analysis of 16S rDNA sequences and a Principal Component Analysis based on morphometric characters provided additional support to the description of O. lahillei and O. xerophylus as two independent lineages within the genus Ornithodoros.
Assuntos
Ornithodoros/classificação , Ornithodoros/fisiologia , Doenças dos Roedores/epidemiologia , Sigmodontinae , Infestações por Carrapato/veterinária , Animais , Argentina/epidemiologia , Proteínas de Artrópodes/genética , Proteínas de Artrópodes/metabolismo , Chile/epidemiologia , Larva/classificação , Larva/crescimento & desenvolvimento , Larva/fisiologia , Dados de Sequência Molecular , Ornithodoros/genética , Ornithodoros/crescimento & desenvolvimento , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Doenças dos Roedores/parasitologia , Análise de Sequência de DNA/veterinária , Especificidade da Espécie , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/parasitologiaRESUMO
Ornithodoros brasiliensis Aragão é um carrapato endêmico do Brasil, restrito às regiões serranas e frias do estado do Rio Grande do Sul. [...] O presente trabalho teve por objetivos estudar a morfologia e a biologia de O. brasiliensis, em condições de laboratório, bem como investigar a presença de bactérias do gênero Rickettsia em espécimes coletados. Ninfas e adultos foram alimentados em cobaias de laboratório e as fêmeas acasaladas realizaram posturas que resultaram nas gerações sucessivas. A larva e os adultos foram descritos e redescritos, e comparados com as espécies próximas, O. rostratus e O. turicata. Análises moleculares de uma porção do gene 16S rDNA mitocondrial foram comparadas com as sequências depositadas no GenBank e apresentaram valores de máximo bootstrap de 100% para ambas, O. rostratus e O. turicata. [...] O primeiro ciclo gonotrófico apresentou maior número de ovos depositados, com 139 ± 13,8 (53 197) em relação ao segundo 73,8 ± 10,6 (53 123). A investigação da presença de riquétsia foi avaliada em 107 espécimes recentemente coletados, evidenciando um total de 12 exemplares positivos. O produto amplificado pela PCR foi sequenciado e as análises moleculares apresentaram homologia de 98% com sequências disponibilizadas no Genbank, correspondentes a uma espécie asiática denominada RDa420 (AF497584) e outra brasileira, Rickettsia bellii (DQ865204)
Ornithodoros brasiliensis Aragão is an endemic tick to Brazil, restricted to the highlands and cold regions of the state of Rio Grande do Sul. [..] This work aimed to study the morphology and biology of O. brasiliensis, under laboratory conditions, and investigate the presence of bacteria of the genus Rickettsia in the collected ticks. Nymphs and adults were fed on laboratory guinea pigs, and mated females laid eggs that resulted in the successive generations. The larvae and adults have been described and redescribed, respectively, and compared with the closely related species, O. rostratus and O. turicata. [...] The first gonotrophic cycle presented higher average number of eggs deposited 139 ± 13,8 (53-197) that the second 73,8 ± 10,6 (53 123). The investigation to the presence of rickettsia was performed in 109 recently collected ticks, showing a total of 12 positive specimens. The amplified PCR product was sequenced and molecular analyzes showed 98% homology with sequences available in Genbank, corresponding to an Asian species named RDa420 (AF497584) e another Brazilian strain named Rickettsia bellii (DQ865204)
Assuntos
Animais , Ornithodoros/crescimento & desenvolvimento , Ornithodoros/fisiologia , Ornithodoros/parasitologia , Rickettsia/isolamento & purificação , Reação em Cadeia da Polimerase/veterináriaRESUMO
The clinical picture produced by the feeding of larvae of Ornithodoros aff. puertoricensis on laboratory mice, was studied using different larval infestation protocols that included 30, 40 or 50 larvae per mouse and control uninfested groups. Clinical effects appeared around 72 h of larval feeding, having a first stage characterized by hyperaemia in both nasal and ocular mucosa, followed by respiratory symptoms (96-120 h) and nervous incoordination (120-144 h). No one mouse evidenced paralysis, and nervous symptoms were never observed in animals infested with only 30 larvae. High mortality (commonly up to 70%) was observed in mice with respiratory symptoms, while 100% of animals in the nervous phase died between 168 and 192 h after the beginning of larval feeding. When some infested mice were treated with a solution of Amitraz the larvae were killed and reversion of symptoms was observed. These effects are ascribed to the presence of a toxin in the saliva of the feeding larvae.
Assuntos
Ornithodoros/metabolismo , Infestações por Carrapato/parasitologia , Toxicoses por Carrapatos/parasitologia , Animais , Feminino , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Ornithodoros/crescimento & desenvolvimento , Infestações por Carrapato/metabolismo , Toxicoses por Carrapatos/metabolismoRESUMO
While banding ferruginous pygmy-owls (Glaucidium brasilianum) and Eastern screech-owls (Megascops asio) in south Texas during 2004, we recorded Philornis mimicola (Diptera: Muscidae) and Ornithodoros concanensis (Acari: Argasidae) parasitizing nestlings. Inspection of nestlings revealed 54 P. mimicola and one O. concanensis. Inspection of nest material revealed 111 P. mimicola, including 57 puparia. The effect (e.g., blood loss, anemia) of these hematophagous parasites might have contributed to the demise of at least one Eastern screech-owl nestling. This is the first record of P. mimicola and O. concanensis parasitizing ferruginous pygmy-owls and Eastern screech-owls.