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• We investigated the seasonality of Amblyomma dubitatum in north-eastern Brazil. • Rickettsial infections were molecularly investigated in the collected ticks. • Amblyomma dubitatum occurred during the whole year in the sampled areas. • An unnamed spotted fever group rickettsia was detected in A. dubitatum. The genus Amblyomma is the most representative tick genus in Brazil and some species act as vectors of pathogenic organisms to animals and humans. Information on the seasonal dynamics of Amblyomma spp. as well as on rickettsial organisms infecting these ticks in some regions in Brazil is still fragmentary. Herein, we investigated the seasonal dynamics and rickettsial infections in Amblyomma dubitatum ticks collected in the Atlantic forest biome in north-eastern Brazil. Using carbon dioxide traps, ticks were collected monthly for two consecutive years. In total, 15,789 ticks were collected: 69 females (0.4%), 116 males (0.7%), 1,067 nymphs (6.8%), and 14,537 larvae (92.1%). All nymphs, females and males were identified as A. dubitatum , whereas larvae were identified as Amblyomma spp. Larvae were more frequent in summer (77% of the larvae collected), whereas nymphs were collected with similar frequency in summer (32.8%), autumn (30.0%) and spring (28.4%). Adults were more frequent in spring (47.6%). A total of 648 ticks (485 nymphs, 60 females, and 103 males) were tested by PCR for the gltA gene of Rickettsia spp. and 87 (13.4%; 95% CI: 10.9–16.3%) were positive. A consensus sequence (size, 350 bp) of 66 gltA gene sequences indicate that the organism detected herein is similar to Rickettsia tamurae, Rickettsia monacencis and Rickettsia sp. strain Pampulha. One of these positive samples was also positive for the ompA gene of spotted fever group rickettsiae, but attempts to sequence the amplicon were not successful. We also tested this sample by a PCR targeting the rickettsial htrA gene, but no amplification product could be detected. This study indicates that A. dubitatum may be a common tick in areas where capybaras are present in north-eastern Brazil, occurring during the whole year. It also suggests the circulation of a spotted fever group rickettsia in this A. dubitatum population, whose identity has yet to be determined. [Display omitted] [ABSTRACT FROM AUTHOR]

Procyonids are reservoirs of many zoonotic infectious diseases, including tick-borne pathogens. The role of coatis (Nasua nasua) in the epidemiology of piroplasmids and Rickettsia has not been fully addressed in Brazil. To molecularly study these agents in coatis and associated ticks, animals were sampled in two urban areas in Midwestern Brazil. Blood (n = 163) and tick (n = 248) DNA samples were screened by PCR assays targeting the 18S rRNA and gltA genes of piroplasmids and Rickettsia spp., respectively. Positive samples were further molecularly tested targeting cox-1, cox-3, β-tubulin, cytB, and hsp70 (piroplasmid) and ompA, ompB, and htrA 17-kDa (Rickettsia spp.) genes, sequenced and phylogenetically analyzed. All coatis' blood samples were negative for piroplasmids, whereas five pools of ticks (2%) were positive for two different sequences of Babesia spp.. The first from Amblyomma sculptum nymphs was close (i.e., ≥ 99% nucleotide identity) to a Babesia sp. previously found in capybaras (Hydrochoerus hydrochaeris); the second from Amblyomma dubitatum nymphs and Amblyomma spp. larvae was identical (100% nucleotide identity) to a Babesia sp. detected in opossums (Didelphis albiventris) and associated ticks. Four samples (0.8%) were positive by PCR to two different Rickettsia spp. sequences, being the first from Amblyomma sp. larva identical to Rickettsia belli and the second from A. dubitatum nymph identical to Rickettsia species from Spotted Fever Group (SFG). The detection of piroplasmids and SFG Rickettsia sp. highlights the importance of Amblyomma spp. in the maintenance of tick-borne agents in urban parks where humans and wild and domestic animals are living in sympatry. [ABSTRACT FROM AUTHOR]

Simple Summary: Capybaras are known hosts for various tick species, but there are limited data regarding the tick-borne pathogens they can carry. We assessed the presence of piroplasmids and Ehrlichia spp. in capybaras and their associated ticks in Goiás state, central-western Brazil. Neither capybaras nor ticks were positive for Ehrlichia spp. However, we detected an undescribed species of protozoan in both the capybaras and ticks. Further research is required for a formal delineation of this protozoan species, as well as to investigate the role of these ticks as vectors and the possible pathogenicity of this parasite to other animals, including horses. Capybaras (Hydrochoerus hydrochaeris) are the largest rodents on Earth. While capybaras are hosts for various tick species, there is limited information regarding the tick-borne pathogens they can carry. We investigated the presence of piroplasmids and Ehrlichia spp. in capybaras and their associated ticks in two peri-urban areas in Goiás state, central-western Brazil. Blood samples collected from 23 capybaras were used to investigate the presence of piroplasmids and Ehrlichia spp. in stained-blood smears and by PCR. Ticks collected from the capybaras were identified morphologically and also tested using PCR for the same pathogens. A total of 955 ticks were collected, including 822 (86.1%) Amblyomma sculptum, 132 (13.8%) Amblyomma dubitatum, and one (0.1%) unidentified larva of Amblyomma sp. Neither the capybaras nor ticks were positive for Ehrlichia spp. However, a stained-blood smear examination revealed the presence of ring-stage and pyriform-shaped merozoites in the erythrocytes of one (4.4%) capybara. In the same way, 47.8% (11/23) and 19.9% (36/181) of blood samples and ticks, respectively, were positive for piroplasmids in the PCR. We successfully sequenced a partial 18S rRNA gene fragment of four samples (two capybaras, one A. sculptum, and one A. dubitatum), and the phylogenetic reconstruction disclosed that the organism reported in the present study clusters within the genus Babesia. Further research is required for a formal delineation of this species (designated as Babesia sp. strain Capybara) and to investigate the hypothesis of A. dubitatum and A. sculptum ticks being vectors. [ABSTRACT FROM AUTHOR]

Ilha Grande, Rio de Janeiro State, is an important island remnant of Atlantic Forest and presents four conservation units. Although dogs are forbidden inside conservation units, in Ilha Grande they are present in all villages, many of them are bred loose, interacting with the tourists, the surrounding forest, and the wild animals. The entry of dogs into forests and encounters with wild animals can promote the exchange of parasites such as ticks and their associated pathogens. We sought to survey the tick fauna of dogs and verify whether host-related factors, as well as localities, and street access are associated with the presence of ticks. We sampled 11 villages, totalling 388 dogs. Ticks were collected off 118 dogs. The most prevalent tick was Rhipicephalus sanguineus sensu lato accounting for 28.87% of tick individuals. Amblyomma ovale and Amblyomma dubitatum were present on seven and one dog, respectively. Dogs with street access, bad body condition, medium and large size, and without defined breed showed a higher occurrence of R. sanguineus s.l. Although we observed dogs on trails, within the forest, and the owners themselves indicated a strong relationship of dogs with the forest, we found a low prevalence of ticks associated with wild animals. [ABSTRACT FROM AUTHOR]

The bacterium Rickettsia rickettsii causes Brazilian spotted fever (BSF), a highly lethal disease that is transmitted by Amblyomma sculptum ticks in areas where capybaras (Hydrochoerus hydrochaeris) are the tick's major hosts. In this study, we evaluated the expansion of a capybara population in a residential park in São Paulo state, and the implications of such expansion to the occurrence of ticks and BSF. The capybara population was quantified during 2004–2013. In 2012, there was a BSF human case in the area, culminating in the complete fencing of the residential park and the official culling of all capybaras. Quantification of ticks in the environment was performed by dry ice traps from 2005 to 2018. Domestic dogs in 2006–2011 and capybaras in 2012 were serologically tested for the presence of anti-R. rickettsii antibodies. Our results show that capybara numbers increased ≈5 times from 2004 (41 capybaras) to 2012 (230 capybaras). Dry ice traps collected A. sculptum and Amblyomma dubitatum. The number of A. dubitatum adult ticks was generally higher than A. sculptum adults during 2005–2006; however, during 2012–2013, A. sculptum outnumbered A. dubitatum by a large difference. During 2016–2018 (after capybara culling), the number of both species fell close to zero. The low numbers of A. sculptum adult ticks during 2005–2006 coincided with relatively low capybara numbers (<80). Thereafter, in 2012, we counted the highest numbers of both A. sculptum ticks and capybaras (230 animals). All 40 canine blood samples were seronegative to R. rickettsii, in contrast to the 48.3% seropositivity (83/172) among capybaras. Our results support that the emergence of BSF in the residential park was a consequence of the increase of the local capybara population, which in turn, provided the increment of the A. sculptum population. Culling the entire capybara population eliminated the risks of new BSF cases. [ABSTRACT FROM AUTHOR]

Simple Summary: Human cases of Brazilian spotted fever (BSF), diagnosed serologically by immunofluorescence assay, have recently been reported in the Goiás state, midwestern Brazil. Because serological cross-reactions among different rickettsial species that belong to the spotted fever group (SFG) are common, the agent responsible for the BSF cases in Goiás remains unknown. We evaluated the presence of anti-Rickettsia spp. antibodies in dogs, horses and capybaras (Hydrochoerus hydrochaeris), as well as rickettsial DNA in ticks collected from these animals and from the environment, in an area where BSF cases have been reported and two areas under surveillance in Goiás. The DNA of Rickettsia that did not belong to the SFG was detected in Amblyomma dubitatum, which was identified by DNA sequencing as Rickettsia bellii. Seroreactivity to SFG and R. bellii antigens was detected in dogs, horses and capybaras, with higher titers for R. bellii in dogs and capybaras. These data demonstrate the circulation of SFG rickettsiae in the region and the need for further research to definitively determine the agent responsible for rickettsiosis cases in this area. Brazilian spotted fever (BSF) is the most important tick-borne diseases affecting humans in Brazil. Cases of BSF have recently been reported in the Goiás state, midwestern Brazil. All cases have been confirmed by reference laboratories by seroconversion to Rickettsia rickettsii antigens. Because serological cross-reactions among different rickettsial species that belong to the spotted fever group (SFG) are common, the agent responsible for BSF cases in Goiás remains unknown. From March 2020 to April 2022, ticks and plasma were collected from dogs, horses and capybaras (Hydrochoerus hydrochaeris), and from the vegetation in an area where BSF cases have been reported and two areas under epidemiological surveillance in Goiás. Horses were infested by Amblyomma sculptum, Dermacentor nitens and Rhipicephalus microplus; dogs by Rhipicephalus sanguineus sensu lato (s.l.), Amblyomma ovale and A. sculptum, and capybaras by A. sculptum and Amblyomma dubitatum. Adults of A. sculptum, A. dubitatum, Amblyomma rotundatum and immature stages of A. sculptum and A. dubitatum, and Amblyomma spp. were collected from the vegetation. DNA of Rickettsia that did not belong to the SFG was detected in A. dubitatum, which was identified by DNA sequencing as Rickettsia bellii. Seroreactivity to SFG and Rickettsia bellii antigens was detected in 25.4% (42/165) of dogs, 22.7% (10/44) of horses and 41.2% (7/17) of capybaras, with higher titers for R. bellii in dogs and capybaras. The seropositivity of animals to SFG Rickettsia spp. antigens demonstrates the circulation of SFG rickettsiae in the region. Further research is needed to fully determine the agent responsible for rickettsiosis cases in this area. [ABSTRACT FROM AUTHOR]

We evaluated the presence of Ehrlichia spp. in unfed capybara ticks, Amblyomma dubitatum, and explored its association with capybaras density, ticks density and environmental variables. We observed that in the Iberá wetlands ecoregion A. dubitatum is infected by "Candidatus Ehrlichia hydrochoerus" and in a lesser extent with an Ehrlichia species closely related to Ehrlichia chaffeensis. The frequency of "Ca. Ehrlichia hydrochoerus" presence in A. dubitatum was not associated with vector abundance, but the probability of finding "Ca. Ehrlichia hydrochoerus"-infected ticks increased when the density of capybaras was low two months before. We hypothesize that when the density of capybaras decreases, A. dubitatum immature stages may seek out alternative hosts one of which could exhibit high realized reservoir competence for "Ca. Ehrlichia hydrochoerus", leading to an increased prevalence of this ehrlichiae in questing A. dubitatum. High minimum temperatures and high cumulative rainfall in the time period previous to tick collection (15 to 60 days) were positively correlated with the prevalence of "Ca. Ehrlichia hydrochoerus" infection in A. dubitatum. Our results suggest that a combination of factors (both biological and abiotic) could raise the risk of human exposure to tick-borne Ehrlichia in the Iberá wetlands ecoregion. [ABSTRACT FROM AUTHOR]

Simple Summary: The knowledge of the dynamics of ticks in wild animals is essential for surveillance of tick-borne diseases. Coatis (Nasua nasua) are mammals that easily adapt to anthropized areas, favoring close contact with domestic animals and humans, favoring the exchange of ticks and tick-borne agents. The present study aimed to investigate the tick diversity on coatis from forest urban areas of midwestern Brazil, as well as the dynamics of ticks during the seasons of the year and the correlation between tick species and gender and age of the sampled coatis. Three tick species were identified parasitizing coatis from forested urban fragments, namely A. dubitatum nymphs, A. sculptum adults and nymphs, and A. ovale adults. After analyzing the obtained results, it is likely that coatis from anthropized areas present tick species diversity lower than those from natural landscapes. The mean intensity and prevalence of Amblyomma larvae and nymphs is similar among males and females as well as in immature and mature animals, which might reflect the gregarious behavior of coatis, since adult males live together with females and offspring outside and inside the mating season, forming large groups of individuals. Understanding the diversity and ecology of ectoparasites in wild animals is essential for surveillance of vector-borne diseases. Coatis (Nasua nasua) easily adapt to anthropized areas, favoring close contact with domestic animals and humans, with the possibility of exchange of ectoparasites and pathogens. The present study aimed to identify the diversity of ticks parasitizing coatis from forest urban areas of midwestern Brazil, to evaluate the seasonal dynamics of ticks during the seasons of the year, and to assess the correlation between tick species and gender and age of the sampled coatis. For this purpose, 103 coatis were captured in two Conservation areas, both located in Campo Grande city, Mato Grosso do Sul state, Midwestern Brazil. The animals' entire body was inspected for the presence of ectoparasites, and ticks were removed for taxonomic identification. In total, 168 captures were performed in both areas during the observational study considering the first capture and recaptures. In total, 2242 ticks were collected: 838 Amblyomma larvae, 1241 A. sculptum nymphs, and 150 A. dubitatum nymphs. Thirteen adult ticks were identified as three males and five females of A. sculptum and two males and three females of A. ovale. While a quantity of Amblyomma larvae was observed in the first months of the year (January, April and May), Amblyomma nymphs showed a higher quantity during the months of July, August, October and November. No statistical difference was observed when comparing mean intensity and prevalence of Amblyomma larvae, nymphs of A. sculptum and A. dubitatum between the two sampled areas, males vs. females and immature vs. mature animals. In conclusion, three tick species were identified parasitizing coatis from forested urban fragments in midwestern Brazil, namely A. dubitatum nymphs, A. sculptum adults and nymphs, and A. ovale adults. Coatis from anthropized areas seem to present tick species diversity lower than those from natural areas. The lack of statistical difference regarding mean intensity and prevalence of Amblyomma larvae and nymphs between males vs. females and immature vs. mature animals might have reflected the gregarious behavior of coatis, since adult males live together with females and offspring outside and inside the mating season, forming large groups of individuals. [ABSTRACT FROM AUTHOR]

Ticks parasitize various hosts, including humans, and are known to transmit pathogens that can be harmful not only to animals but also to humans. To evaluate the possible presence of pathogens in ticks, we aimed to collect and identify tick fauna specimens in Lagoa Comprida Municipal Natural Park, an anthropogenic urban area located in Aquidauana, Mato Grosso do Sul, Brazil. A total of 1216 ticks, of which 51.2% were Amblyomma sculptum , 1.2% were Amblyomma dubitatum , and 41% were Amblyomma spp. were collected. These results show that the prevalence of A. sculptum is significantly higher than that of A. dubitatum across all four seasons. Molecular analyses revealed positive samples for the genus Babesia , including the confirmation of Babesia bigemina in an A. sculptum specimen, marking the first record of this relationship. This unexpected finding demands greater attention and deeper analysis in the context of the epidemiology of tick-borne diseases. • Predominance of Amblyomma sculptum and Amblyomma dibitatum in Lagoa Comprida Municipal Natural Park. • None of the 1216 collected samples tested positive for Rickettsia spp. and Borrelia spp. • Identification of Babesia bigemina DNA in Amblyomma sculptum. [ABSTRACT FROM AUTHOR]

Ticks are distributed worldwide, and in South America, Brazil possesses the largest diversity of them. They are responsible for transmitting a wide range of pathogens to animals and accidentally to humans. The available data on tick species parasitizing wild animals in Paraná State are limited to few reports. Accordingly, the aims of this study were to describe and map the distribution of ticks parasitizing wild animals in Paraná State, southern Brazil, based on unpublished data from records of ticks deposited in two scientific collections, and tick records from previously published studies. Overall, we obtained 976 records of parasitism by ticks from 173 different species of free-ranging wild animals: 2/173 (1.2%) amphibians, 2/173 (1.2%) reptiles, 119/173 (68.8%) birds, 3/173 (1.7%) canids, 2/173 (1.2%) deer, 6/173 (3.5%) felids, 7/173 (4.0%) marsupials, 3/173 (1.7%) mustelid, 2/173 (1.2%) non-human primates, 2/173 (1.2%) procionid, 19/173 (11.0%) rodents, 2/173 (1.2%) Suine, 1/173 (0.6%) tapir, and 3/173 (1.7%) Xenarthra. A total of 6,794 ticks (1,163 males, 749 females, 428 adults of non-defined sex, 1,824 nymphs, 2,370 larvae, and 260 not identified stages) were recorded. The following tick species were recorded: Amblyomma aureolatum, Amblyomma brasiliense, Amblyomma calcaratum, Amblyomma coelebs, Amblyomma dissimile, Amblyomma dubitatum, Amblyomma fuscum, Amblyomma geayi, Amblyomma incisum, Amblyomma longirostre, Amblyomma nodosum, Amblyomma ovale, Amblyomma parkeri (some published as A. geayi), Amblyomma parvum, Amblyomma pseudoconcolor, Amblyomma rotundatum, Amblyomma sculptum (some published as Amblyomma cajennense senso lato), Amblyomma tigrinum, Amblyomma triste, Amblyomma sp., Haemaphysalis juxtakochi, Haemaphysalis sp., Ixodes auritulus, Ixodes fuscipes (some published as Ixodes aragaoi), Ixodes loricatus, Ixodes paranaensis, Ixodes schulzei, Ixodes sp., and Rhipicephalus microplus. Amblyomma aureolatum and A. longirostre were highly prevalent on wild hosts. Ring-tailed coati (Nasua nasua) was the host species with the highest tick richness in Paraná State, Brazil. Also, we provide the first record of the tick-host association A. fuscum on felid (Leopardus guttulus), and R. microplus on rodent (Sphiggurus villosus). [ABSTRACT FROM AUTHOR]

The order Piroplasmida encompasses tick-borne pathogens of veterinary and medical importance positioned in two main families: Babesiidae and Theileriidae. Even though previous studies carried out in Brazil recorded the occurrence of piroplasmid species circulating in small mammals, 18S RNA gene sequences were only partially sequenced, preventing the assessment of their phylogenetic positioning. The current study aimed to detect and characterize, using morphological, molecular, and bioinformatic approaches, piroplasmids from wild mammals and associated ticks sampled in Central-Western Brazil. Out of 67 Didelphis albiventris sampled, 22 (16.4%) were positive for piroplasmids by PCR. In contrast, none of the 48 small rodents and 14 capybaras (Hydrochoerus hydrochaeris) was PCR-positive. Four Amblyomma dubitatum ticks—one from Rattus rattus, one from H. hydrochaeris, and two from D. albiventris—out of 114 Amblyomma spp. DNA samples were positive for piroplasmids by PCR. The phylogenetic inference performed using the near-complete 18S rRNA gene positioned the putative novel piroplasmid species detected in D. albiventris and associated A. dubitatum ticks near to Babesia sensu lato clade (Western group—cluster III) and distant from the Australian marsupial-associated piroplasms. Phylogenetic inferences based on two additional molecular markers, namely hsp-70 and cox-1, supported the near-complete 18S rRNA gene phylogenetic inference. Finally, the partial 18S rRNA gene sequences detected in ticks from rodents (R. rattus and H. hydrochaeris) showed 97.2–99.4% identity with the Piroplasmida previously detected in a capybara from Brazil, raising evidence that a still uncharacterized piroplasmid species has been identified in the capybara, the largest rodent species from South America. [ABSTRACT FROM AUTHOR]

Brazil concentrates the largest number of primate species in the world. In the present study, an extensive literature review of ticks on New World wild monkeys has been carried out, demonstrating that between the years 1912 to 2018, 182 larvae, 137 nymphs and 31 adult ticks (10 males and 21 females) were collected on 78 primates (from 12 different species) in 28 distinct localities in the Brazilian territory. Additionally, examination of allotments of 11 tick collections of Brazil revealed that from 1919 to 2019, 93 larvae, 91 nymphs and 175 adult ticks (62 males and 113 females) were collected from 100 monkeys (among 20 different species) from 43 localities in distinct Brazilian biomes. Overall, 19 tick species were identified on wild primates in the country: Amblyomma aureolatum (Pallas, 1772), Amblyomma cajennense (Fabricius, 1787) sensu stricto, Amblyomma coelebs Neumann, 1899, Amblyomma dubitatum Neumann, 1899, Amblyomma geayi Neumann, 1899, Amblyomma incisum Neumann, 1906, Amblyomma longirostre (Koch, 1844), Amblyomma naponense (Packard, 1869), Amblyomma nodosum Neumann, 1899, Amblyomma ovale Koch, 1844, Amblyomma parkeri Fonseca & Aragão, 1952, Amblyomma romarioi Martins, Luz & Labruna, 2019, Amblyomma rotundatum Koch, 1844, Amblyomma sculptum Berlese, 1888, Haemaphysalis juxtakochi Cooley, 1946, Ixodes fuscipes Koch, 1844, Rhipicephalus microplus (Canestrini, 1888), Rhipicephalus sanguineus (Latreille, 1806) sensu lato,and Ornithodoros rostratus Aragão, 1911. The presence of A. incisum, A. naponense, A. nodosum, A. rotundatum and I. fuscipes on monkeys is recorded for the first time. Thisresearch is therefore a significant contribution to the knowledge of tick speciesassociated with non-human primates in the Neotropical region. [ABSTRACT FROM AUTHOR]

We evaluated the role of communities of small mammals from three distinct areas in a region of Cerrado mixed with Atlantic Forest remains for maintenance of tick fauna. Thirty-nine marsupials (Gracilinanus agilis, n = 34; Marmosa paraguaiana, n = 4; Didelphis albiventris, n = 1) and 33 rodents (Oecomys cleberi, n = 10; Nectomys squamipes, n = 4; Calomys tener, n = 4; Hylaeamys megacephalus, n = 4; Akodon sp., n = 3; Rattus rattus, n = 3; Cerradomys subflavus, n = 2; Mus musculus, n = 2; Rhipidomys macrurus, n = 1) were captured. Solely G. agilis and the four rodent species (N. squamipes, R. macrurus, C. subflavus and Akodon sp.) were infested. Four tick species were collected (Amblyomma dubitatum, Amblyomma sculptum, Ixodes loricatus and Ornithodoros mimon). A. dubitatum was the most abundant tick species on hosts. Capture success was higher in the dry season, but the infestation was similar in both seasons. Forested habitats, particularly riparian forests, resulted in higher number of hosts and ticks collected (from hosts and from vegetation), compared to pastures and anthropized sites. The association between C. subflavus and I. loricatus and between A. dubitatum and N. squamipes observed here is the first recorded in Cerrado biome. Areas with more patches of forest, including the Atlantic Forest fragments, tend to present a richest community of small mammals and associated ticks. [ABSTRACT FROM AUTHOR]

This research reports ticks on wild raptors in Brazil. Between the years 1936 and 2019, 127 larvae, 230 nymphs and 34 adult ticks were collected on 92 raptors (among 27 different species) from 35 localities in distinct Brazilian biomes. Additionally, an extensive literature review on ticks on wild raptors has been carried out, demonstrating that from 1993 to 2016, 29 larvae, 81 nymphs, 29 adults and 186 indeterminate immature ticks (larvae or nymphs) were collected on 41 raptors (16 different species) in 17 distinct localities in the Brazilian territory. The following tick species were identified on wild raptors in the country: Amblyomma aureolatum (Pallas, 1772), Amblyomma auricularium (Conil, 1878), Amblyomma brasiliense Aragão, 1908, Amblyomma cajennense (Fabricius, 1787) sensu stricto, Amblyomma calcaratum Neumann, 1899, Amblyomma coelebs Neumann, 1899, Amblyomma dubitatum Neumann, 1899, Amblyomma longirostre (Koch, 1844), Amblyomma nodosum Neumann, 1899, Amblyomma ovale Koch, 1844, Amblyomma parkeri Fonseca & Aragão, 1952, Amblyomma sculptum Berlese, 1888, Haemaphysalis juxtakochi Cooley, 1946, Rhipicephalus microplus (Canestrini, 1888), and Rhipicephalus sanguineus (Latreille, 1806) sensu lato. This study is therefore a significant contribution to our knowledge of the ticks associated with Brazilian raptors. [ABSTRACT FROM AUTHOR]

From January 2012 to August 2018, a total of 1013 specimens of ticks were collected and identified from 116 captive or free-ranging wild animals from Tocantins State, northern Brazil. The following tick-host associations were recorded: Amblyomma rotundatum Koch, 1844 on amphibians; Amblyomma cajennense sensu lato (Fabricius, 1787), Amblyomma humerale Koch, 1844 and A. rotundatum on reptiles; A. cajennense s. l. on bird; and Amblyomma auricularium (Conil, 1878), A. cajennense s. l., A. cajennense sensu stricto, Amblyomma dubitatum Neumann, 1899, Amblyomma geayi Neumann, 1899, Amblyomma naponense (Packard, 1869), Amblyomma nodosum Neumann, 1899, Amblyomma oblongoguttatum Koch, 1844, Amblyomma ovale Koch, 1844, Amblyomma pseudoconcolor Aragão, 1908, A. rotundatum, Amblyomma sculptum Berlese, 1888, Amblyomma tigrinum Koch, 1844, Haemaphysalis juxtakochi Cooley, 1946, Dermacentor nitens Neumann, 1897, Rhipicephalus microplus (Canestrini, 1887), and Rhipicephalus sanguineus sensu lato (Latreille, 1806) on mammalian hosts. The presence of A. dubitatum, A. naponense and H. juxtakochi in Tocantins is recorded for the first time. [ABSTRACT FROM AUTHOR]

Background: Brazilian spotted fever (BSF), caused by the bacterium Rickettsia rickettsii, has been associated with the transmission by the tick Amblyomma sculptum, and one of its main hosts, the capybara (Hydrochoerus hydrochaeris). Methods: During 2015–2019, we captured capybaras and ticks in seven highly anthropic areas of São Paulo state (three endemic and four nonendemic for BSF) and in two natural areas of the Pantanal biome, all with established populations of capybaras. Results: The BSF-endemic areas were characterized by much higher tick burdens on both capybaras and in the environment, when compared to the BSF-nonendemic areas. Only two tick species (A. sculptum and Amblyomma dubitatum) were found in the anthropic areas; however, with a great predominance of A. sculptum (≈90% of all ticks) in the endemic areas, in contrast to a slight predominance of A. dubitatum (≈60%) in the nonendemic areas. Tick species richness was higher in the natural areas, where six species were found, albeit with a predominance of A. sculptum (≈95% of all ticks) and environmental tick burdens much lower than in the anthropic areas. The BSF-endemic areas were characterized by overgrowth populations of A. sculptum that were sustained chiefly by capybaras, and decreased populations of A. dubitatum. In contrast, the BSF-nonendemic areas with landscape similar to the endemic areas differed by having lower tick burdens and a slight predominance of A. dubitatum over A.sculptum, both sustained chiefly by capybaras. While multiple medium- to large-sized mammals have been incriminated as important hosts for A. sculptum in the natural areas, the capybara was the only important host for this tick in the anthropic areas. Conclusions: The uneven distribution of R. rickettsii infection among A. sculptum populations in highly anthropic areas of São Paulo state could be related to the tick population size and its proportion to sympatric A. dubitatum populations. [ABSTRACT FROM AUTHOR]

A previous study in Paulicéia Municipality, south-eastern Brazil, reported 9.7% of the Amblyomma triste ticks to be infected by Rickettsia parkeri, a bacterial pathogen that causes spotted fever in humans. These A. triste ticks were shown to be associated with marsh areas, where the marsh deer Blastocerus dichotomus is a primary host for this tick species. During 2008-2009, blood serum samples were collected from 140 horses, 41 dogs, 5 opossums ( Didelphis albiventris) and 26 humans in farms from Pauliceia Municipality. Ticks were collected from these animals, from vegetation and from additional wildlife in these farms. Overall, 25% (35/140) of the horses, 7.3% (3/41) of the dogs, 3.8% (1/26) of the humans and 100% (5/5) of the opossums were seroreactive (titre ≥64) to spotted fever group ( SFG) Rickettsia spp. Multivariate statistical analysis indicated that horses that were allowed to forage in the marsh were 4.8 times more likely to be seroreactive to spotted fever group ( SFG) Rickettsia spp than horses that did not forage in the marsh. In addition, horses that had been living in the farm for more than 8.5 years were 2.8 times more likely to be seroreactive to SFG Rickettsia spp than horses that were living for ≤8.5 years. Ticks collected from domestic animals or from vegetation included Amblyomma cajennense, Amblyomma coelebs, Amblyomma dubitatum, Dermacentor nitens and Rhipicephalus microplus. By PCR analyses, only one pool of A. coelebs ticks from the vegetation was shown to be infected by rickettsiae, for which DNA sequencing revealed to be Rickettsia amblyommii. Ticks (not tested by PCR) collected from wildlife encompassed A. cajennense and Amblyomma rotundatum on lizards ( Tupinambis sp), and A. cajennense and A. triste on the bird Laterallus viridis. Our results indicate that the marsh area of Paulicéia offers risks of infection by SFG rickettsiae. [ABSTRACT FROM AUTHOR]

Abstract: This study evaluated the presence and seasonal activity of free-living ticks in remaining marsh areas by the Paraná river, in Brazil. Eight field trips (once per season) for collection of ticks were performed during 2 years. Using CO2 traps, dragging, and visual inspection of vegetation, five free-living tick species were collected, in the following order of abundance: Amblyomma cajennense, Amblyomma dubitatum, Amblyomma triste, Amblyomma coelebs, and Amblyomma nodosum. The seasonal pattern of A. cajennense was characterized by the highest peaks for adult ticks in the summer/spring months, for nymphs in the winter and for larvae in the autumn and winter. A. dubitatum and A. triste presented similar seasonal patterns characterized by peaks of adult ticks in the autumn. Nymphs of A. dubitatum peaked in the winter of the first year and in the winter/spring of the second year. A. triste was the only species to be collected in significantly higher numbers in the marsh than in surrounding drier areas such as forest patches. Among domestic animals living close the marsh areas, horses were infested by Anocentor nitens, A. cajennense, and Boophilus microplus, bovines were infested solely by B. microplus, and dogs were infested by Rhipicephalus sanguineus. Adults of A. triste showed to be well adapted to the marsh environment. This result, at least partially, explains local previous observations on the association of A. triste with marsh deer, as this vertebrate host inhabits mainly the marsh area. [Copyright &y& Elsevier]