Rickettsial agents in avian ixodid ticks in northeast Brazil

New insights on the Rickettsia-tick-wild bird associations in the Western Amazon, Brazil

Several studies have highlighted the importance of balancing wildlife and plant life to mitigate the spread of ticks and their pathogenic microorganisms. This balance is essential for preserving the health of wildlife, domestic animals, and, consequently, human populations. However, human activities, characterized by habitat destruction and fragmentation, have brought humans and domestic animals closer to wild bird populations, which act as dispersers of ticks of public health importance. In light of these challenges, this study aimed to determine the frequency of occurrence and abundance of tick species in wild birds in the upland forests of the southwestern Brazilian Amazon. Data were collected in two municipalities: Rio Branco (four urban forest fragments) and Manoel Urbano (an area of continuous forest in the Parque Estadual Chandless), both located in the state of Acre, Brazil. Birds were captured between May and September 2021 using 10 mist nets placed in five transects of each study area, resulting in a sampling effort of 1210 net hours. Captured birds were thoroughly inspected for tick infestation, and when found, they were removed using forceps. These ticks were identified using a stereomicroscope and specific taxonomic keys, as well as molecular analysis by PCR. We captured 315 birds, of which 95 (30.15 %) were infested with ticks in the larval and nymph stages. A total of 368 ticks belonging to the genus Amblyomma were collected. This included species such as Amblyomma coelebs, Amblyomma geayi, Amblyomma humerale, Amblyomma longirostre, Amblyomma nodosum, and Amblyomma maculatum sensu lato (s.l.). These results highlight 13 new associations between wild birds and ticks of the genus Amblyomma and reveal, for the first time, the presence of Amblyomma maculatum s.l. and rickettsiae from the Spotted Fever Group. These findings expand the knowledge of the epidemiology of ticks and rickettsial agents of public health importance in the region.

Survey of Salmonella spp., Escherichia coli and Staphylococcus aureus in Ardeids: Investigation of potential reservoirs

ardeids are wild birds well adapted to urban and periurban environments. However, the association of wildlife with humans and livestock increases the chances of transmission of microorganisms between wild animals, domestic animals and humans. The present study aimed to investigate the occurrence of Salmonella spp., Escherichia coli and Staphylococcus aureus in Ardeids living in a nest located on the Campus of the Universidade Federal de Lavras (UFLA), in Lavras, Minas Gerais, Southeast Region of Brazil. Ten great egrets (Ardea alba) and five cattle egrets (Bubulcus ibis) found dead or dying were collected for the study, examined, and cloacal swabs were collected from each bird. Most of these birds (92.85 %) were chicks. Necropsy was carried out, after euthanasia of the dying animals. Organs/tissues samples from all birds were collected for histopathologic exam and for microbiologic analysis when macroscopic lesions were present. Salmonella spp. were detected in 42.85 % of the collected egrets and E. coli in 64.28 %. Staphylococcus aureus was not detected in any of them. The vast majority of PCR positive colonies was obtained by cloacal swab, which means that the agents were being eliminated by the birds' excreta and may represent a significant public health concern.

Ticks (Acari: Ixodidae) on resident and migratory wild birds in Orinoquia region, Colombia

Several species of hard ticks, including those of the genera Ixodes, Haemaphysalis, Amblyomma, and Rhipicephalus, are of medical and veterinary importance and have been reported in association with Neotropical wild birds. Colombia, known for its great bird diversity, has 57 confirmed tick species. However, there are few studies on the association between wild birds and ticks in Colombia. The Orinoquia region, a migratory center in Colombia, provides a unique opportunity to study wild bird-tick associations and their implications for tick-borne disease dynamics. Our study, conducted between October and December 2021, aimed to identify hard ticks infesting resident and migratory wild birds in the department of Arauca and to assess the presence of bacteria from the genera Anaplasma, Borrelia, Ehrlichia, Rickettsia, and piroplasms. A total of 383 birds were examined, of which 21 were infested. We collected 147 ticks, including Amblyomma dissimile (larvae), Amblyomma longirostre (nymphs), Amblyomma mixtum (adults), and Amblyomma nodosum (larvae and nymphs). We did not detect bacterial DNA in the tested ticks; however, piroplasm DNA was detected in ticks from three of the infested birds. Of the 21 bird-tick associations, six are new to the Americas, and interesting documentation of piroplasm DNA in A. longirostre, A. nodosum, and A. dissimile ticks from wild birds in the region. This study provides valuable insights into the ticks associated with wild birds and their role in the dispersal of ticks and pathogens in Colombia, enhancing our understanding of tick life cycles and tick-borne disease dynamics.

Parasitism on domestic cats by Amblyomma auricularium and serological evidence of exposure to Rickettsia amblyommatis

The domestic cat is not considered a primary host for any specific tick species; however, it can be affected by some Ixodidae species, such as Rhipicephalus sanguineus sensu lato and Amblyomma spp. The study reports parasitism by Amblyomma auricularium and the detection of anti-Rickettsia spp. antibodies in domestic cats from a rural property in the Afrânio municipality, Pernambuco, Brazil. Amblyomma auricularium (24 nymphs, six females, and four males) and Amblyomma sp. (42 larvae) parasitized three cats, and 73 free-living ticks were captured in armadillo burrows: A. auricularium (36 nymphs, six females, five males) and Amblyomma sp. (26 larvae). Blood samples from cats were collected and the obtained plasma were subjected to indirect immunofluorescence assay (IFA) to detect antibodies against Rickettsia antigens. Thus, anti-Rickettsia spp. antibodies were determined (titers ranging from 128 to 512) and showed a predominant antibody response to Rickettsia amblyommatis or a very closely related genotype. This study reports the first infestation of nymphs and adults of A. auricularium on cats in a new area of occurrence in the semi-arid region of Northeastern Brazil and reports for the first time the presence of anti-Ricketsia antibodies in cats in the region, with R. amblyommatis as the probable infectious agent.

New tick records with notes on rickettsial infection from the wildlife of the state of Espírito Santo, southeastern Brazil

This work aimed to report ticks infesting the wildlife among 15 municipalities of the state of Espírito Santo between 2016 and 2021, within the Atlantic Forest biome of southeastern Brazil. A total of 576 tick specimens (187 males, 56 females, 149 nymphs, and 184 larvae) was collected from 41 species of wild vertebrates (two reptiles, nine mammals, and 30 birds). Ticks were identified by morphological or molecular methods into 18 species, being 12, four, one and one of the genera Amblyomma, Ixodes, Rhipicephalus and Ornithodoros, respectively. Amblyomma rotundatum was the only species collected from reptiles. Ticks collected from mammals were identified as Amblyomma brasiliense, Amblyomma calcaratum, Amblyomma dubitatum, Amblyomma longirostre, Amblyomma nodosum, Amblyomma pacae, Amblyomma sculptum, Amblyomma varium and Rhipicephalus microplus. Amblyomma sculptum was the species found on the widest variety of hosts, collected from four mammal orders and five bird orders. Passeriformes birds were infested by Amblyomma fuscum, A. longirostre (also found on non- passerine birds), A. nodosum, Amblyomma parkeri, Amblyomma romarioi, A. varium and Ixodes loricatus. An adult female of Ixodes rio was collected from a Piciformes bird. Seabirds of the order Procellariiformes were infested by Ixodes percavatus sensu lato and Ixodes uriae. The argasid Ornithodoros capensis was collected from an offshore metallic platform that was used by Suliformes seabirds. Rickettsial agents of the spotted fever group, Rickettsia amblyommatis and Rickettsia sp. strain Pampulha, were detected in the ticks A. longirostre [from the Paraguayan hairy dwarf porcupine (Coendou spinosus)] and A. dubitatum [from the capybara (Hydrochoerus hydrochaeris)], respectively. The following nine tick species are reported for the first time in Espírito Santo state: A. calcaratum, A. fuscum, A. pacae, A. parkeri, A. romarioi, I. loricatus, I. rio, I. uriae, and O. capensis. Although it is also the first report of I. uriae in Brazil, we do not consider it established in the country. Multiple new tick-host associations are reported in the present study.

Diversity of rickettsiae in ticks (Acari: Ixodidae) collected from wild vertebrates in part of the Amazon, Cerrado, and Pantanal biomes in Brazil

Ticks parasitizing 102 wild animals in the states of Mato Grosso and Goiás, Brazil were collected between 2015 and 2018. A total of 2338 ticks (865 males, 541 females, 823 nymphs, and 109 larvae) belonging to four genera (Amblyomma, Dermacentor, Haemaphysalis, and Rhipicephalus) and at least 21 species were identified. DNA extraction and a molecular survey for rickettsial agents were performed on 650 ticks. The results revealed parasitism by the following species: Rickettsia amblyommatis in Amblyomma cajennense s.s., A. cajennense s.l., Amblyomma coelebs, Amblyomma humerale, Amblyomma longirostre, Amblyomma nodosum, Amblyomma scalpturatum, Amblyomma sculptum, and Amblyomma romitii; Rickettsia parkeri in Amblyomma nodosum, Amblyomma ovale, Amblyomma scalpturatum, and Amblyomma triste; Rickettsia rhipicephali in Haemaphysalis juxtakochi; Rickettsia sp. in A. cajennense s.s., A. nodosum, and A. sculptum, and lastly, 'Candidatus Rickettsia andeanae' in Amblyomma parvum and Rhipicephalus microplus. This study expands the body of knowledge about tick parasitism among wild animals, including new data concerning tick-host associations, and provides information about the epidemiology of tick-borne pathogens in the Center-West region of Brazil.

Ticks (Acari: Ixodidae, Argasidae) associated with wild birds in Argentina

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.

Detection of Rickettsia tamurae-like and other spotted fever group rickettsiae in ticks (Acari: Ixodidae) associated with wild birds in the Western Amazon, Brazil

Ticks are vectors for several pathogens, including bacteria belonging to the Rickettsia genus, such as Rickettsia rickettsii and Rickettsia parkeri, the causative agents of spotted fever. The aim of the present study was to investigate the tick species richness and rickettsial agents associated with wild birds captured in the Humaita Forest Reserve, Acre, in the Western Amazon region. Wild birds were captured with ornithological nets for visual inspection with the purpose of collecting ticks, which were identified through morphological analyses and molecular tests for several genes (12S rDNA, 16S rDNA, gltA, ompA, and sca4). A total of 607 wild birds were captured, 12% of which were parasitized by 268 ticks of the Amblyomma genus, with new host-parasite associations reported for Amblyomma calcaratum, Amblyomma geayi, Amblyomma longirostre, Amblyomma naponense, Amblyomma nodosum, and Amblyomma varium. Of the total ticks collected, 113 were tested for the presence of rickettsial DNA fragments, with 19 testing positive for R. parkeri in A. geayi, Rickettsia tamurae-like in Amblyomma sp., and Rickettsia amblyommatis in A. geayi, A. longirostre, and Amblyomma sp. We detected R. tamurae-like in Amblyomma larvae for the first time in the Western Brazilian Amazon biome, and registered spotted fever group rickettsiae, although the relevance of the detected species in a public health context should be further explored in South America, as well as new host-parasite interactions in this underexplored region.

Immature hard ticks infected with Rickettsia amblyommatis on breeding birds from Pantanal

Immature hard ticks from the genus Amblyomma feed on blood from a wide range of Neotropical avian hosts. They serve as vectors for pathogens of medical and veterinary importance, such as Rickettsia agents of the spotted fever group (SFG). Hence, determining ecological factors that increase encounter rates between immature ticks and their avian hosts may contribute to the understanding of tick-borne diseases transmission. Here, we used 720 individual birds from 96 species surveyed in the Brazilian Pantanal to test whether host breeding season influenced tick infestation probabilities. Additionally, collected ticks were screened for Rickettsia agents to describe new avian-tick-bacteria associations. Our models revealed that the probability of an individual bird being infested with immature ticks was similar during the breeding and pre-breeding season, but higher loads of immature tick stages were found during the breeding season. Host sex did not predict infestation probability, but Rickettsia agents recovered from ticks were more prevalent during the pre-breeding season. The new records of host usage by larvae and nymphs of Amblyomma in Pantanal and the growing body of tick surveys in Neotropical avian communities, suggest that immature ticks may benefit from avian blood sources during their annual cycle. The low number of infected ticks with Rickettsia agents on Pantanal birds suggest that this vertebrate group are likely not acting as reservoirs for these microorganisms. However, long-term surveys at the same site are imperative to determine which tick species are acting as reservoirs for Rickettsia agents in Pantanal and determine whether birds are playing a role in dispersing ticks and tick-borne pathogens.

Rickettsia amblyommatis in Ticks: A Review of Distribution, Pathogenicity, and Diversity

Rickettsia amblyommatis is a potentially pathogenic species of Rickettsia within the spotted fever group vectored by ticks. While many studies have been published on this species, there is debate over its pathogenicity and the inhibitory role it plays in diagnosing illnesses caused by other spotted fever group Rickettsia species. Many publications have recorded the high infection prevalence of R. amblyommatis in tick populations at a global scale. While this species is rather ubiquitous, questions remain over the epidemiological importance of this possible human pathogen. With tick-borne diseases on the rise, understanding the exact role that R. amblyommatis plays as a pathogen and inhibitor of infection relative to other tick-borne pathogens will help public health efforts. The goal of this review was to compile the known literature on R. amblyommatis, review what we know about its geographic distribution, tick vectors, and pathogenicity, assess relatedness between various international strains from ticks by phylogenetic analysis and draw conclusions regarding future research needed.

Seroprevalence and detection of Rickettsia spp. in wild birds of Arauca, Orinoquia region, Colombia

Wild birds have an important role as hosts of ticks infected by rickettsiae. However, the role of birds as reservoirs of tick-borne rickettsiae is unknown and poorly understood. This is particularly relevant in several tropical and subtropical areas, where migration influences the global spread of ectoparasites and pathogens of public health importance. This research aimed to detect and evaluate the exposure to spotted fever group rickettsiae in wild birds that could represent reservoirs in the Department of Arauca in the Colombian Orinoquia region. Sampling was conducted in three municipalities of the Department of Arauca (Colombia). Blood samples were collected from 255 birds and processed to obtain serum (n = 155) and DNA (n = 255) samples. The serum samples were processed for indirect immunofluorescence assays (IFA) for the detection of antibodies to Rickettsia rickettsii, Rickettsia parkeri, Rickettsia amblyommatis, Rickettsia rhipicephali, and Rickettsia bellii. Additionally, we investigated rickettsiae DNA in blood samples by amplification of the citrate synthase gene (gltA). The IFA results revealed seropositivity in 97 samples from 54 species of resident and migratory birds. No sample was positive for rickettsial DNA. The presence of antibodies in 62.5% of the sera indicates previous exposure of these birds to rickettsiae. The null detection of rickettsiae in the blood of seropositive birds is possibly due to a short period of bacteremia. Experimental studies are required to improve our understanding of the role of wild birds as sources of rickettsial infections in ticks.

Occurrence of tick-borne pathogens in dogs in a coastal region of the state of Ceará, northeastern Brazil

The aim of this study was to determine the occurrence of tick-borne pathogens (Ehrlichia canis, Babesia vogeli, Hepatozoon spp. and Rickettsia spp.) in dogs in Vila de Jericoacoara, coastal region of Ceará, Brazil. Blood samples were collected from 153 animals and analyzed using molecular and serological methods. Sixty animals were found to be infected or exposed to at least one of the pathogens studied. Babesia vogeli was the most prevalent pathogen (15%), followed by E. canis (13.7%) and Hepatozoon spp. (11.8%), which was identified as Hepatozoon canis through sequencing. Twenty dogs (13%) were seroreactive to Rickettsia spp. Rhipicephalus sanguineus sensu lato was observed on 11.8% of the animals. There were associations between age (< 3 years old) and positivity for B. vogeli, and between habitation (stray dogs) and positivity for H. canis. There were also associations between anemia and infection with H. canis, and between leukopenia and exposure to Rickettsia spp. No association was detected between clinical alterations and infection with or exposure to the pathogens studied. The results confirmed that pathogens of veterinary importance are circulating in northeastern Brazil and showed that dogs are exposed to Rickettsia species with zoonotic potential, thus indicating a need for vector control measures.

Rickettsial infection in free-ranging capybaras (Hydrochoerus hydrochaeris) and their ticks (Acari, Ixodidae) in the Caatinga and Atlantic forest biomes, Northeastern Brazil

Caatinga and Atlantic Forest are Brazilian biomes threatened by anthropogenic disturbances, which are a serious threat to biodiversity and favor the emergence of zoonotic pathogens. Capybara populations are increasingly present in urban and rural areas due to the loss of their natural habitats. There are no studies on the rickettsial infection in these rodents in Northeastern Brazil, although there are case records of Brazilian Spotted Fever (BSF) in this region. In this context, we evaluated rickettsial infection in capybaras and their ticks in four areas of the Atlantic Forest and Caatinga biomes in Northeastern Brazil. Blood sera from 21 capybaras were tested by indirect immunofluorescence assay (IFA) using Rickettsia rickettsii, R. parkeri, and R. amblyommatis antigens. Blood samples and ticks (Amblyomma sp., Amblyomma dubitatum and Amblyomma sculptum) were tested by PCR, targeting a fragment of the rickettsial gltA gene and R. bellii primers. Overall, 15 out of 21 capybaras (71.4%) reacted positively (titer ≥64) to at least one of the three Rickettsia antigens tested, with final titers ranging from 64 to 1024. No rickettsial DNA was found in capybara blood samples. Rickettsial DNA was detected in 22 of 31 adult tick pools using gltA gene, being all nine pools of A. sculptum and 16 of the 19 of A. dubitatum, but all samples were negative to R. bellii specific primers. All attempts to sequence the amplicon were unsuccessful, indicating a possible low rickettsial load in the tick samples. The present study reports for the first time the serological evidence of Rickettsia spp. infection in free-ranging capybaras and suggest the rickettsial infection in A. sculptum and A. dubitatum in the Caatinga and Atlantic Forest biomes in Northeastern Brazil.

Tick infestation on birds in an urban Atlantic Forest fragment in north-eastern Brazil

Birds are important hosts for various tick species, playing a significant role in their biological life cycle and dispersion. In this study, we investigated tick infestations on birds trapped in an urban remnant of Atlantic Forest in Pernambuco state, Brazil. From February 2015 to March 2017, 541 birds belonging to 52 species were trapped with mist nets and examined for ectoparasites. Birds trapped in the late successional forest were significantly more infested than birds trapped in the early successional forest. In the same way, ectoparasite infestation varied significantly according to bird weight and collection plot. Overall, 198 birds (36.6%) belonging to 27 species were parasitized by ectoparasites (i.e., ticks, lice and/or mites). Ectoparasites were effectively collected from 111 birds, of which 99 belonging to 20 species were infested by ticks (n = 261), namely, Amblyomma longirostre (13 nymphs), Amblyomma nodosum (21 nymphs), Amblyomma varium (one nymph), and Amblyomma spp. (five nymphs and 221 larvae). Most of the ticks (> 90%) were collected from Passeriformes. This study provides the second record of A. varium in Pernambuco state and confirms that birds, especially Passeriformes, are important hosts for larvae and nymphs of Amblyomma spp. in the Atlantic Forest biome of Pernambuco.

Migration and season explain tick prevalence in Brazilian birds

Neotropical birds are mostly parasitized by immature ticks and act as reservoir hosts of tick-borne pathogens of medical and veterinary interest. Hence, determining the factors that enable ticks to encounter these highly mobile hosts and increase the potential for tick dispersal throughout migratory flyways are important for understanding tick-borne disease transmission. We used 9682 individual birds from 572 species surveyed across Brazil and Bayesian models to disentangle possible avian host traits and climatic drivers of infestation probabilities, accounting for avian host phylogenetic relationships and spatiotemporal factors that may influence tick prevalence. Our models revealed that the probability of an individual bird being infested with tick larvae and nymphs was lower in partial migrant hosts and during the wet season. Notably, infestation probability increased in areas with a higher proportion of partial migrant birds. Other avian ecological traits known to influence tick prevalence (foraging habitat and body mass) and environmental condition that might constrain tick abundance (annual precipitation and minimum temperature) did not explain infestation probability. Our findings suggest that migratory flyways harbouring a greater abundance of migrant bird hosts also harbour a higher prevalence of immature ticks with potential to enhance the local transmission of tick-borne pathogens and spread across regions.

Diversity of ticks and detection of Rickettsia amblyommatis infecting ticks on wild birds in anthropogenic landscapes in Bahia state, northeast Brazil

Birds are important hosts in the maintenance and spread of ticks worldwide, including several species of Amblyomma which harbor rickettsial agents as members of the spotted fever group (SFG). The current survey shows the diversity of tick and rickettsial agents infecting ticks on wild birds from an Atlantic rainforest in the state of Bahia, Brazil. A total of 365 birds were captured, representing two orders, 22 families and 51 species, among which 68 specimens (18.6%) were parasitized. Overall, 132 immature ticks (81 larvae and 51 nymphs) were identified to species level, representing six recognized species of the genus Amblyomma: Amblyomma longirostre (n = 45), Amblyomma nodosum (n = 40), Amblyomma varium (n = 5), Amblyomma parkeri (n = 2), Amblyomma coelebs (n = 3) and Amblyomma calcaratum (n = 1). Amplification by PCR and sequencing of rickettsial genes (gltA and ompA), detected the presence of Rickettsia DNA in 12 (9.1%) of the ticks. Rickettsia amblyommatis was the only agent detected in nine larvae and two nymphs of A. longirostre and one nymph of A. varium with 99-100% similarity.

Serological evidence of Rickettsia in horses from a semi-arid Brazilian region

Brazilian spotted fever (BSF) is a common tick-borne disease caused by Rickettsia rickettsii. Horses are the primary hosts of the main vector, Amblyomma sculptum, and are considered efficient sentinels for circulation of Rickettsia. Therefore, the aim of this study was to detect antibodies reactive to R. rickettsii antigens in horses from a non-endemic area in the north-central region of Bahia state, Brazil. Blood samples and ticks were collected from 70 horses from the municipalities of Senhor do Bonfim, Antônio Gonçalves, Pindobaçu, and Campo Formoso. The sera obtained were tested by an indirect immunofluorescence assay to detect anti-Rickettsia antibodies. Overall, 5.7% (4/70) of the horses reacted to R. rickettsii antigens. Ticks were collected from 18.6% (13/70) of the horses and were identified as A. sculptum and Dermacentor nitens. Despite being a non-endemic area, seropositive animals were identified in our study, suggesting circulation of rickettsial agents in the region. This is the first serological survey of this agent in horses from the north-central region of Bahia, and further studies are needed to understand the epidemiology of BSF in these locations.

Role of Zoo-Housed Animals in the Ecology of Ticks and Tick-Borne Pathogens-A Review

Ticks are ubiquitous ectoparasites, feeding on representatives of all classes of terrestrial vertebrates and transmitting numerous pathogens of high human and veterinary medical importance. Exotic animals kept in zoological gardens, ranches, wildlife parks or farms may play an important role in the ecology of ticks and tick-borne pathogens (TBPs), as they may serve as hosts for local tick species. Moreover, they can develop diseases of varying severity after being infected by TBPs, and theoretically, can thus serve as reservoirs, thereby further propagating TBPs in local ecosystems. The definite role of these animals in the tick-host-pathogen network remains poorly investigated. This review provides a summary of the information currently available regarding ticks and TBPs in connection to captive local and exotic wildlife, with an emphasis on zoo-housed species.

Rickettsia spp. in ticks (Acari: Ixodidae) from wild birds in Caldas, Colombia

Several bacteria belonging to the genus Rickettsia are recognized as causal agents of diseases in domestic and wild animals and humans. These bacteria are considered emerging or reemerging and are transmitted by ticks, fleas, and lice vectors. In recent decades, there have been reports of rickettsias in ticks of the genus Amblyomma, Ixodes, and Haemaphysalis collected from wild birds. Accordingly, birds play a plausible role in the transport and spread of ticks infected by Rickettsia spp. In this study, we performed molecular detection of Rickettsia species in ticks collected from wild birds in the department of Caldas, Colombia. We detected and identified Rickettsia amblyommatis, 'Candidatus Rickettsia colombianensi' and a Rickettsia sp. closely related to 'Candidatus Rickettsia tarasevichiae' and Rickettsia canadensis. This study contributes to the knowledge on infection by Rickettsia in ticks collected from wild birds in Colombia. We also provide the first reports of infection by R. amblyommatis in the genus Ixodes collected from wild birds in South America and the presence of Rickettsia at elevations above 3000 m a.s.l.

Rickettsia parkeri strain Atlantic rainforest in ticks (Acari: Ixodidae) of wild birds in Arauca, Orinoquia region of Colombia

Birds are important hosts for the development of the immature stages of several tick species that are vectors for disease-causing microorganisms in animals and humans. Colombia has the highest number of bird species worldwide; however, there is scarce data on the role of birds in the circulation of ticks and their associated pathogens, such as rickettsiae. The department of Arauca has a high diversity of resident and migratory (boreal and austral) birds and ticks associated with the transmission of Rickettsia. The objective of this research was to identify tick species parasitizing birds and to detect Rickettsia species in these ectoparasites. We conducted samplings in the municipalities of Arauca, Cravo Norte, and Tame between November of 2018 and August of 2019. Birds were captured using mist nets and examined for the presence of tick species. The collected ticks were morphologically and molecularly identified. Furthermore, we detected rickettsiae in ticks by amplifying fragments of the citrate synthase (gltA) and outer membrane protein (ompB) genes. We captured 606 birds belonging to 25 families and 115 species. Tick infestation rate was 3.3% (20/606) in the birds captured and eight new associations between wild birds and ticks are reported for the American continent. We identified four tick species: Amblyomma nodosum, Amblyomma longirostre, Amblyomma mixtum, and Amblyomma sp.. Moreover, we confirmed the presence of Rickettsia parkeri strain Atlantic rainforest in A. nodosum, a medically-relevant rickettsia due to cases of rickettsiosis in the American continent. This finding manifests the importance of wild birds as hosts and dispersal agents of ticks infected with pathogenic rickettsiae, as well as the need to monitor migratory birds in the Orinoquia and other regions of Colombia and America.

Amblyomma nodosum Neumann, 1889 on collared anteaters (Tamandua tetradactyla) from the Andean region of Colombia

Amblyomma nodosum is a Neotropical tick species distributed from Mexico to Argentina, with adult individuals infesting different mammal species, including anteaters (Pilosa: Myrmecophagidae). Few reports in Colombia have recorded this species in departments such as Meta, Tolima and Valle del Cauca. In this paper we describe this species using taxonomic, morphometric and molecular methods after collecting individuals parasitizing collared anteaters (Tamandua tetradactyla) in the departments of Cundinamarca and Tolima. Adult specimens were identified based on current taxonomic keys and different morphometric variables were documented in nonengorged individuals. Also, DNA was extracted for PCR amplification and sequencing of 16S rDNA, COI and ITS2 genes. Phylogenetic trees were built. One hundred and thirty-four adult ticks were collected and identified as Amblyomma nodosum, based on morphological, morphometric, molecular and phylogenetic analyses. This is the first study to report the presence of this tick species in the department of Cundinamarca, using multiple identification approaches, thus expanding its geographical records in Colombia.

Immature ticks on wild birds and the molecular detection of a novel Rickettsia strain in the Ibitipoca State Park, southeastern Brazil

Birds are recognized hosts of ticks, especially for the immature stages which may harbor various species and strains of Rickettsia. To explore landscapes inhabited by birds and their ticks would expand the knowledge on host-parasite relationships and the rickettsiae. The aim of this paper was to record the diversity of ticks collected on wild birds and assess the phylogenetic position of a novel Rickettsia strain detected in immature ticks. Birds were captured in the Ibitipoca State Park, located in the Minas Gerais state, southeastern Brazil, as part of a long-term research project on the ecology of ticks, birds and Rickettsia. We found three tick species parasitizing birds: Amblyomma aureolatum (63 larvae, 10 nymphs), Haemaphysalis leporispalustris (28 larvae, seven nymphs) and Amblyomma romarioi (27 larvae). Among these, A. aureolatum was the most abundant species including 54% (73/135) of the collected ticks. New tick-host records were: A. romarioi on Turdus amaurochalinus and H. leporispalustris on Thamnophilus caerulescens, Saltator similis and Zonotrichia capensis. Of the 82 ticks tested for Rickettsia spp. by PCR, two larvae (2.5%) of A. romarioi were infected with 'Candidatus Rickettsia paranaensis', a novel putative Rickettsia species closely related to Rickettsia africae, Rickettsia sibirica and Rickettsia parkeri, as corroborated by our phylogenetic analysis. Finally, we present a list of all records of immature stages of H. leporispalustris on passerine birds in Brazil.

Spotted fever group Rickettsia and Borrelia sp. cooccurrence in Amblyomma sculptum in the Midwest region of Brazil

More than 70 tick species are found in Brazil, distributed over five genera and including main vectors of infectious disease agents affecting both animals and humans. The genus Amblyomma is the most relevant for public health in Brazil, wherein Amblyomma aureolatum, Amblyomma ovale and Amblyomma sculptum have been incriminated as vectors of Rickettsia and Borrelia pathogens. The objective of this study was to investigate the presence of Rickettsia spp. and Borrelia spp. in ticks in the Brazilian mid-western savannah. DNA extraction, PCR for Borrelia spp. (flgE gene) and Rickettsia spp. (ompA and gltA genes) and subsequent sequencing were performed. A total of 1875 ticks were collected and identified as A. sculptum except for two Amblyomma coelebs ticks. Molecular evidence for Borrelia spp. and Rickettsia parkeri was found in A. sculptum. This is the first molecular evidence for R. parkeri in A. sculptum ticks in the Midwest region and Borrelia spp. circulating in a tick of the Amblyomma genus in Brazil.

New Records of Ticks of Genus Amblyomma Koch, 1844 (Acari: Ixodidae) for Ecuador

PURPOSE

In Ecuador, knowledge of the diversity and geographic distribution of ticks, as well as their importance as vectors, is scarce. Within the family Ixodidae, the genus Amblyomma is the most diverse and parasitizes wild and domestic animals. This genus is represented by 19 species in Ecuador, 12 of which occur in the continental territory and 7 in the Galapagos Islands. In this way, the objective of this work was to update the diversity of ticks reported for Ecuador on wild and domestic animals.

METHODS

The specimens were collected manually on mammals and birds, in four localities belonging to the Sierra and Amazon of Ecuador and were kept in tubes with 96% ethyl alcohol. After that, all specimens were separated into immatures, males and females and were identified using their morphological characters.

RESULTS

This study records Amblyomma coelebs Neumann, 1899, Amblyomma longirostre (Koch, 1844) Neumann, 1905 and Amblyomma varium Koch, 1844 for the first time in Ecuador. Thus, the genus Amblyomma is currently represented by 22 species. In addition, their hosts, distribution, and importance are also discussed.

CONCLUSIONS

Knowing the diversity of ticks that wildlife possesses, its interrelation with the domestic fauna, and the possible pathogens that could be transmitting could significantly contribute to wildlife's conservation.

Retrospective and new records of ticks (Acari: Argasidae, Ixodidae) from the state of Maranhão, an Amazon-Cerrado transition area of Brazil

The Brazilian state of Maranhão is located in a transition area of the Amazon and Cerrado biomes, where there is a rich fauna of vertebrates. This study aimed to update the list of the ticks occurring in Maranhão, through a compilation of literature records and examination of three tick collections, plus the addition of unpublished collections of ticks from road-killed animals during recent years. Our results indicate that the tick fauna of Maranhão includes 26 species: seven in the family Argasidae (Antricola guglielmonei, Argas miniatus, Ornithodoros cavernicolous, Ornithodoros hasei, Ornithodoros mimon, Ornithodoros rietcorreai and Ornithodoros rudis); and 19 in the family Ixodidae (Amblyomma auricularium-provisional, Amblyomma cajennense sensu stricto, Amblyomma calcaratum, Amblyomma dissimile, Amblyomma geayi, Amblyomma longirostre, Amblyomma naponense, Amblyomma nodosum, Amblyomma oblongoguttatum, Amblyomma ovale, Amblyomma parvum, Amblyomma rotundatum, Amblyomma sculptum, Amblyomma triste, Dermacentor nitens, Ixodes luciae, Haemaphysalis juxtakochi, Rhipicephalus microplus, and Rhipicephalus sanguineus sensu lato). Eleven of the above species are reported for the first time in Maranhão. We consider previous reports of Ornithodoros talaje and Amblyomma pseudoconcolor in Maranhão as misidentification with O. hasei and A. auricularium, respectively. Until 1958, only 11 tick species were reported in Maranhão, with no additional reports until 2009. During 2010-2019, 15 additional species were reported. We also highlight the importance of ticks for public and veterinary health in Maranhão.

Low host specificity and lack of parasite avoidance by immature ticks in Brazilian birds

Ticks are ectoparasites that feed on blood of a broad taxonomic range of terrestrial and flying vertebrates and are distributed across a wide range of environmental conditions. Here, we explore the biotic and abiotic factors on infestation probability of ticks of the genus Amblyomma and assess the degree of host specificity based on analysis of 1028 birds surveyed across Brazil. We show that tick infestation rates exhibited considerable variation across the 235 avian species analyzed and that the probability of an individual bird being parasitized by immature ticks (larvae and nymphs) increased with annual precipitation. Host phylogeny and two host ecological traits known to promote tick exposure (body mass and foraging behavior) did not predict infestation probability. Moreover, immature ticks displayed a low degree of host specificity at the family level. Lastly, tick occurrence in birds carrying infection with avian malaria and related parasites did not differ from those free of these haemosporidian parasites, indicating a lack of parasite avoidance by immature ticks. Our findings demonstrate that tick occurrence in birds across Brazilian biomes responds to environmental factors rather than ecological and evolutionary host attributes.

Ticks and Associated Pathogens From Rescued Wild Animals in Rainforest Fragments of Northeastern Brazil

The Ixodidae family comprises ticks that are hematophagous ectoparasites and are considered vectors of several hemoparasites from the Anaplasmataceae family and the genus Hepatozoon, Babesia, and Rickettsia. These ectoparasites parasitize domestic and wild animals belonging to several vertebrate groups. Ticks are highly adapted to different biomes and thus possess a wide geographical distribution. In the Brazilian state of Bahia, localized in the Northeast region, there are large rainforest fragments. Studies have rarely been carried out on ticks, and their hemoparasites, that parasitize wild animals in this region. Thus, this study aimed to identify the tick species parasitizing wild animals rescued in rainforest fragments of Bahia and investigate the presence of hemoparasites in tick tissues. During a 2-year period, 238 ticks were collected from 41 wild mammalians, reptiles, and amphibians. These ectoparasites were taxonomically classified according to their morphological characteristics. The ticks identified belonged to five different species from the Ixodidae family: Amblyomma varium, Amblyomma rotundatum, Amblyomma nodosum, Ixodes loricatus, and Rhipicephalus sanguineus. For the first time, an A. rotundatum parasitizing the Mesoclemmys tuberculata turtle was described. PCR assays using DNA extracted from salivary glands or midgut of the ticks were performed to detect specific DNA fragments of hemoparasites from the genus Rickettsia, Ehrlichia, Babesia, Hepatozoon, and from the Anaplasmataceae family. The results showed positive detection of the Rickettsia genus (7.9%), Anaplasmataceae family (15.8%), and Hepatozoon genus (15.8%). Specific DNA from the Ehrlichia and Babesia genera were not detected in these samples. Specific DNA from members of the Anaplasmataceae family was detected in A. varium for the first time. The present work showed that amphibians, reptiles, and mammals from Bahia's Atlantic Forest areparasitized by different tick species, and that these ectoparasites present pathogens in their tissues that impact both humans and animals due to their zoonotic potential.

Hemoparasites in ticks of wild birds of Serra dos Órgãos National Park, state of Rio de Janeiro, Brazil

The aim of this study is to detect the presence of tick-borne agents of genera Rickettsia, Borrelia, Babesia, Ehrlichia and Anaplasma in ticks collected from native wild birds in the state of Rio de Janeiro. Birds were captured and observed carefully to find the ectoparasites. DNA detection of hemoparasites was performed by means of the polymerase chain reaction (PCR). The sequences obtained were analyzed and their homologies were compared to the available isolates in the GenBank platform database. A total of 33 birds were captured from 20 different species, of which 14 were parasitized by Amblyomma longirostre (n = 22). There was absence of DNA from agents of the genera Babesia, Anaplasma and Ehrlichia in the evaluated samples. The phylogenetic analysis indicated that one sample had 100% identity with Rickettsia bellii (KJ534309), the other two samples showed 100% identity with Rickettsia sp. Aranha strain and strain AL (EU274654 and AY360216). The positive sample for R. bellii was also demonstrated to be positive for Borrelia sp., which presented a similarity of 91% with Borrelia turcica (KF422815). This is the first description of Borrelia sp. in ticks of the genus Amblyomma in South America.

Detection of Rickettsia spp. in ticks associated to wild mammals in Northeastern Brazil, with notes on an undetermined Ornithodoros sp. collected from marsupials

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.

Molecular detection of Bartonella spp. and Rickettsia spp. in bat ectoparasites in Brazil

The family Streblidae comprises a monophyletic group of Hippoboscoidea, hematophagous dipterans that parasitize bats. Bartonella spp. and Rickettsia spp. have been reported in bats sampled in Europe, Africa, Asia, North, Central and South America. However, there are few reports on the Bartonella and Rickettsia bacteria infecting Hippoboscoidea flies and mites. While Spinturnicidae mites are ectoparasites found only in bats, those belonging to the family Macronyssidae comprise mites that also parasitize other mammal species. This study investigates the occurrence and assesses the phylogenetic positioning of Bartonella spp. and Rickettsia spp. found in Streblidae flies and Spinturnicidae and Macronyssidae mites collected from bats captured in Brazil. From May 2011 to April 2012 and September 2013 to December 2014, 400 Streblidae flies, 100 Macronyssidaes, and 100 Spinturnicidae mites were collected from bats captured in two sites in northeastern Nova Iguaçu, Rio de Janeiro, southeastern Brazil. Forty (19.8%) out of 202 Streblidae flies were positive for Bartonella spp. in qPCR assays based on the nuoG gene. Among the flies positive for the bacterium, six (18%) were Paratrichobius longicrus, seven (29%) Strebla guajiro, two (40%) Aspidoptera phyllostomatis, five (11%) Aspidoptera falcata, one (10%) Trichobius anducei, one (25%) Megistopoda aranea, and 18 (32%) Trichobius joblingi, and collected from bats of the following species: Artibeus lituratus, Carollia perspicillata, Artibeus planirostris, Sturnira lilium, and Artibeus obscurus. Six sequences were obtained for Bartonella (nuoG [n = 2], gltA [n = 2], rpoB [n = 1], ribC = 1]). The phylogenetic analysis based on gltA (750pb) gene showed that the Bartonella sequences clustered with Bartonella genotypes detected in bats and ectoparasites previously sampled in Latin America, including Brazil. Only one sample (0.49%) of the species Trichobius joblingi collected from a specimen of Carollia perspicillata was positive for Rickettsia sp. in cPCR based on the gltA gene (401bp). This sequence was clustered with a 'Candidatus Rickettsia andaenae" genotype detected in an Amblyomma parvum tick collected from a rodent in the southern region of Brazilian Pantanal. The sampled Macronyssidae and Spinturnicidae mites were negative for Bartonella spp. and Rickettsia spp. This study demonstrated the first occurrence of Bartonella spp. and Rickettsia spp. DNA in Streblidae flies collected from bats in Brazil.

Wild pigs as sentinels for hard ticks: A case study from south-central Florida

As a result of shifts in the habitable range of ticks due to climate change and the ongoing threat of exotic tick species introductions, efficient surveillance tools for these pests and disease vectors are needed. Wild pigs are habitat generalists, distributed throughout most of the United States, and often hunted recreationally or removed as part of management programs, making them potentially useful sentinel hosts for ticks. We compared ticks collected from captured wild pigs and standard tick dragging methods on a south-central Florida cattle ranch from May 2015-August 2017. Three hundred and sixteen wild pigs were surveyed, and 84 km spanning three habitat types (seminative pasture, improved pasture, and hammock) were dragged. In total, 1023 adults of four species (Amblyomma auricularium, Amblyomma maculatum, Dermacentor variabilis, and Ixodes scapularis) were collected from wild pigs, while 39 adults of three species (A. auricularium, A. maculatum, and I. scapularis) were collected from drags. Only one immature specimen, a nymph, was collected from a pig, while dragging collected 2808 larvae and 150 nymphs. Amblyomma maculatum comprised 96% of adults collected from pigs, while A. maculatum, I. scapularis, and A. auricularium comprised 38%, 33%, and 28% of adults collected from drags, respectively. Adults of all tick species found on drags were found on pigs, and wild pig surveillance detected adults of an additional species not found on drags. Dragging was far superior for collection of immatures but not for adults of most species found in this study. These findings suggest wild pigs could be used as a sentinel for the detection of tick species. When combined with ongoing wild pig research, hunting, or management, wild pig surveillance can provide an effective method to survey for adult tick presence of some species of interest and may assist in tracking the range expansion of some tick species.

Rickettsia spp. among wild mammals and their respective ectoparasites in Pantanal wetland, Brazil

The genus Rickettsia comprises obligatory intracellular bacteria, well known to cause zoonotic diseases around the world. The present work aimed to investigate the occurrence of Rickettsia spp. in wild animals, domestic dogs and their respective ectoparasites in southern Pantanal region, central-western Brazil, by molecular and serological techniques. Between August 2013 and March 2015, serum, whole blood and/or spleen samples were collected from 31 coatis, 78 crab-eating foxes, seven ocelots, 42 dogs, 110 wild rodents, and 30 marsupials. Serum samples from canids, felids, rodents and marsupials were individually tested by indirect fluorescent antibody test (IFAT) in order to detect IgG antibodies to Rickettsia rickettsii, Rickettsia parkeri and Rickettsia amblyommatis. DNA samples from mammals and ectoparasites were submitted to a multiplex qPCR assay in order to detect and quantify spotted fever group (SFG) and typhus group (TG) rickettsiae and Orientia tsutsugamushi. Positive samples in qPCR assays were submitted to conventional PCR assays targeting gltA, ompA, ompB and htrA genes, followed by sequencing and phylogenetic analyses. The ticks collected (1582) from animals belonged to the species Amblyomma sculptum, Amblyomma parvum, Amblyomma ovale, Amblyomma tigrinum, Rhipicephalus (Boophilus) microplus, Rhipicephalus sanguineus sensu lato and Amblyomma auricularium. Overall, 27 (64.2%) dogs, 59 (75.6%) crab-eating foxes and six (85.7%) ocelots were seroreactive (titer≥64) to at least one Rickettsia species. For 17 (40.4%) dogs, 33 (42.3%) crab-eating foxes, and two (33.3%) ocelots, homologous reactions to R. amblyommatis or a closely related organism were suggested. One hundred and sixteen (23.5%) tick samples and one (1.2%) crab-eating fox blood sample showed positivity in qPCR assays for SFG Rickettsia spp. Among SFG Rickettsia-positive ticks samples, 93 (80.2%) belonged to A. parvum, 14 (12%) belonged to A. sculptum species, three (2.5%) belonged to A. auricularim, and six (5.2%) were Amblyomma larval pools. Thirty samples out of 117 qPCR positive samples for SFG Rickettsia spp. also showed positivity in cPCR assays based on gltA, htrA and/or ompB genes. The Blast analyses showed 100% identity with 'Candidatus Rickettsia andeanae' in all 30 sequences obtained from gltA, htrA and/or ompB genes. The concatenated phylogenetic analysis based on gltA and 17-kDa htrA genes grouped the Rickettsia sequences obtained from tick samples in the same clade of 'Candidatus Rickettsia andeanae'. The present study revealed that wild and domestic animals in southern Pantanal region, Brazil, are exposed to SFG rickettsiae agents. Future studies regarding the pathogenicity of these agents are necessary in order to prevent human cases of rickettsiosis in Brazilian southern Pantanal.

Ehrlichia canis and Rickettsia spp. in dogs from urban areas in Paraiba state, northeastern Brazil

The aims of our study was to identify Ehrlichia canis and antibodies against Rickettsia spp. belonging to the spotted fever group (SFG) in dogs sampled from Paraiba state, northeastern Brazil. Blood and serum samples collected by convenience from dogs in urban areas of five municipalities were analyzed by real-time PCR for the detection of E. canis DNA and by immunofluorescence assay test (IFAT) for the identification of antibodies against Rickettsia rickettsii, R. felis, R. parkeri, R. amblyommii and R. rhipicephali antigens. E. canis DNA was detected in 8.9% (64/719) of the blood samples, whereas 5.63% (43/763) of the serum samples were positive for at least one of the Rickettsia antigens tested by IFAT. This study showed for the first time the occurrence of E. canis and suggested the circulation of SFG Rickettsia in dogs in the study region of Paraiba state, northeastern Brazil.

Molecular analyses reveal an abundant diversity of ticks and rickettsial agents associated with wild birds in two regions of primary Brazilian Atlantic Rainforest

Brazilian wild birds are recognized as frequent and important hosts for immature stages of more than half of the 32 recognized species of Amblyomma ticks recorded in that country. Several species of Amblyomma harbor rickettsial agents, including members of the spotted fever group (SFG). Most studies on this topic relied primarily on morphological characterization and reported large portions of the collected ticks at the genus rather than species level. Clearly, this factor may have contributed to an underestimation of tick diversity and distribution and makes comparisons between studies difficult. The current investigation combined morphological and molecular analyses to assess the diversity of ticks and rickettsial agents associated with wild birds, captured in two regions of native Atlantic rainforest, in the state of Rio de Janeiro, Brazil. A total of 910 birds were captured, representing two orders, 34 families and 106 species, among which 93 specimens (10.2%), were parasitized by 138 immature ticks (60 larvae and 78 nymphs), representing 10 recognized species of the genus Amblyomma; together with two reasonably well classified haplotypes (Amblyomma sp. haplotype Nazaré and Amblyomma sp. strain USNTC 6792). Amplification by PCR and sequencing of rickettsial genes (htrA, gltA, ompA and ompB), demonstrated the presence of Rickettsia DNA in 48 (34%) of the ticks. Specifically, Rickettsia bellii was detected in a single larva and a single nymph of A. aureolatum; R. amblyomatis was found in 16 of 37 A. longirostre and was recorded for the first time in three nymphs of A. calcaratum; R. rhipicephali was detected in 9 (47%) of 19 Amblyomma sp. haplotype Nazaré ticks. The remaining ticks were infected with genetic variants of R. parkeri, namely strain ApPR in 12 A. parkeri and seven Amblyomma sp. haplotype Nazaré ticks, with the strain NOD found in two specimens of A. nodosum. Interestingly, a single larvae of A. ovale was shown to be infected with the emerging human pathogen Rickettsia sp. strain Atlantic rainforest (ARF), suggesting a possible role for birds in the dispersal of ticks infected with this variant of R. parkeri. The diversity of ticks and Rickettsia recorded in this study is, to our knowledge, the most abundant recorded to date in Brazil and highlighted the value of employing methods capable of providing species level identification of the ixodofauna of wild birds.

Amblyomma auricularium (Ixodida: Ixodidae) in Florida: New Hosts and Distribution Records

Previous published evidence for the occurrence of an exotic armadillo tick, Amblyomma auricularium (Conil), in Florida is scant, but we found it is fully established and integrated into the state's tick fauna. We collected 11,192 specimens of this tick from naturalized nine-banded armadillos, Dasypus novemcinctus L., and 14 other species of wild native mammals and birds in Florida, while sampling statewide during 2004 through 2007. In all, we document its specific presence only in 14 contiguous South Florida counties. Moreover, we report the first collections of A. auricularium from the Virginia opossum (Didelphis virginiana Kerr), common raccoon [Procyon lotor (L.)], cotton deermouse [Peromyscus gossypinus (Le Conte)], gray fox [Urocyon cinereoargenteus (Schreber)], eastern spotted skunk [Spilogale putorius (L.)], and white-tailed deer [Odocoileus virginianus (Zimmerman)]. For the first time on birds, we report the collection of this tick from the broad-winged hawk [Buteo platypterus (Vieillot)], northern cardinal [Cardinalis cardinalis (L.)], Carolina wren [Thryothorus ludovicianus (Latham)], gray catbird [Dumetella carolinensis (L.)], and yellow-rumped warbler [Setophaga coronata (L.)]. In addition, we report unattached A. auricularium collected from humans for the first time, and additional new collections from domestic dogs, Canis lupus familiaris L.

Rickettsia (Rickettsiales: Rickettsiaceae) Vector Biodiversity in High Altitude Atlantic Forest Fragments Within a Semiarid Climate: A New Endemic Area of Spotted-Fever in Brazil

Rickettsioses are re-emerging vector-borne zoonoses with a global distribution. Recently, Rickettsia sp. strain Atlantic rainforest has been associated with new human spotted-fever (SF) cases in Brazil, featuring particular clinical signs: eschar formation and lymphadenopathy. These cases have been associated with the tick species, Amblyomma ovale From 2010 until 2015, the Brazilian Health Department confirmed 11 human SF cases in the Maciço de Baturité region, Ceará, Brazil. The present study reports the circulation of Rickettsia spp. in vectors from this entirely new endemic area for SF. A total of 1,727 ectoparasites were collected in this area from the environment, humans, and wild and domestic animals. Samples (n = 887) were screened by polymerase chain reaction (PCR), targeting the gltA and ompA rickettsial genes. Sequencing and phylogenetic analyses of gltA gene amplicons were carried out for 13 samples positive for both screening PCRs. Fragments of gltA and ompA from three samples were cloned, sequenced, and analyzed further. A. ovale and Rhipicephalus sanguineus specimens, collected from dogs, were found to be infected with Rickettsia sp. str. Atlantic rainforest, suggesting the importance of dogs in the epidemic cycle. Candidatus Rickettsia andeanae, Rickettsia felis, and Rickettsia bellii were also found infecting ticks and fleas in five municipalities, demonstrating the broad diversity of rickettsiae in circulation in the studied area. This study reports, for the first time, evidence of infection with Rickettsia sp. strain Atlantic rainforest in A. ovale and R. sanguineus in Ceará, and Ca. R. andeanae in an Atlantic rainforest environment of Brazil.

Molecular detection of Rickettsia rhipicephali and other spotted fever group Rickettsia species in Amblyomma ticks infesting wild birds in the state of Minas Gerais, Brazil

The current study evaluated parasitism of wild birds by ticks in a fragment of Atlantic Forest in the state of Minas Gerais, Brazil, and examined the ticks for rickettsial agents. Birds were captured during 2014 and 2015 and ticks were identified by sequencing fragments of the 16S and 12S ribosomal DNA. Among 260 birds representing 19 families and 52 species, a total of 69 (26.5%) were found to be infested by larvae (LL) and/or nymphs (NN) of Amblyomma longirostre (Koch, 1844) (45 LL, 4 NN), Amblyomma calcaratum Neumann, 1899 (9 LL, 15 NN), Amblyomma nodosum Neumann, 1899 (2 NN), Amblyomma parkeri Fonseca and Aragão, 1952 (21 LL), Amblyomma sp. haplotype Nazaré (77 LL), and Haemaphysalis leporispalustris (Packard, 1869) (17 LL, 1 NN). The use of PCR and sequencing of the rickettsial genes gltA, htrA, ompA and ompB, revealed the presence of "Candidatus Rickettsia amblyommii" in A. longirostre (13/49; 26%) and Rickettsia parkeri (strain ApPR) in both A. parkeri (1/21; 5%) and haplotype Nazaré (42/77; 55%) ticks. In addition, we detected Rickettsia rhipicephali in 31 (40%) of the 77 haplotype Nazaré ticks. This is the first record of this rickettsial agent in a species of the genus Amblyomma. The pathogenic potential of this bacterium is undetermined, but the unprecedented association with Amblyomma ticks may represent a cause for concern for public and/or animal health.

First report of "Candidatus Rickettsia amblyommii" in west coast of Mexico

We report the first case of "Candidatus Rickettsia amblyommii" detected in Amblyomma mixtum ticks on humans on the west coast of Mexico. This is the most western record of "Ca. R. amblyommii" in the Western Hemisphere, representing the first record for the western coast of the Americas. Even if the record is far from the previously known locations for the species it does not represent a new record regarding temperature, precipitation and topographic parameters. Since "Ca. R. amblyommii" antibodies have been detected in patients suspected of Rocky Mountain spotted fever, and the tick A. mixtum has been associated with humans, it is important to consider "Ca. R. amblyommii" as a potential risk for the human population that has not been considered at risk before.

Detection of rickettsiae in fleas and ticks from areas of Costa Rica with history of spotted fever group rickettsioses

Outbreaks of spotted fevers have been reported in Costa Rica since the 1950s, although vectors responsible for transmission to humans have not been directly identified. In this study, species of Rickettsia were detected in ectoparasites from Costa Rica, mostly from five study sites where cases of spotted fevers have been reported. Ticks and fleas were collected using drag cloths or directly from domestic and wild animals and pooled according to species, host, and location. Pools were analyzed initially by PCR to detect a fragment of Rickettsia spp. specific gltA gene, and those positive were confirmed by detection of htrA and/or ompA gene fragments. Partial sequences of the gltA gene were obtained, as well as at least one ompA and/or ompB partial sequence of each species. Rickettsia spp. were confirmed in 119 of 497 (23.9%) pools of ticks and fleas analyzed. Rickettsia rickettsii was identified in one nymph of Amblyomma mixtum and one nymph of Amblyomma varium. Other rickettsiae present were 'Candidatus Rickettsia amblyommii' in A. mixtum, Amblyomma ovale, Dermacentor nitens, and Rhipicephalus sanguineus s. l.; Rickettsia bellii in Amblyomma sabanerae; Rickettsia felis in Ctenocephalides felis; and Rickettsia sp. similar to 'Candidatus R. asemboensis' in C. felis, Pulex simulans, A. ovale, and Rhipicephalus microplus. Results show the presence of rickettsiae in vectors that may be responsible for transmission to humans in Costa Rica, and evidence suggests exposure to rickettsial organisms in the human environment may be common. This is the first study to report R. rickettsii in A. varium and in A. mixtum in Costa Rica.

New records for Amblyomma sculptum (Ixodidae) on non-passerine birds in Brazil

Abstract The aim of this paper was to provide new records of Amblyomma sculptum on two species of terricolous birds in two areas of the Cerrado (savannah- like) bioma: two specimens of Cariama cristata were captured in the state of Goiás and one specimen ofCrax fasciolata was captured in the state of Minas Gerais. One of the C. cristata was parasitized by 15 larvae, six nymphs, one male and two females whereas the C. fasciolata was parasitized by seven larvae and eight nymphs. This paper presents a new locality for occurrence of parasitism A. sculptum in C. cristata and a new host for C fasciolata.

Rickettsial infection in ticks (Acari: Ixodidae) of wild animals in midwestern Brazil

Ticks collected in the last two decades from free-living and captive wild animals from 28 municipalities of the Brazilian state of Mato Grosso were identified and tested using molecular methods for the presence of rickettsial agents. A total of 4467 ticks (229 larvae, 1676 nymphs, 1565 males, 997 females) representing 27 ixodid species were collected from 235 species of amphibians, reptiles, birds, and mammals from three different ecoregions (Pantanal, Cerrado, and Amazonia). The species Amblyomma parkeri, Amblyomma romitii, Amblyomma varium and Ixodes luciae are reported for the first time in the state of Mato Grosso. Amongst 538 ticks tested by molecular methods for rickettsial infection, we detected 'Candidatus Rickettsia amblyommii' infecting Amblyomma cajennense sensu stricto and Amblyomma coelebs, Rickettsia sp. strain Atlantic rainforest infecting Amblyomma ovale, Rickettsia sp. strain NOD infecting Amblyomma nodosum, and 'Candidatus Rickettsia andeanae' infecting Amblyomma sculptum. Our results represent an impressive expansion of knowledge on tick fauna and rickettsiae and are essential for understanding the ecology of ticks and tick-borne diseases in the Neotropical region, particularly in midwestern Brazil.

Additional information about tick parasitism in Passeriformes birds in an Atlantic Forest in southeastern Brazil

The habits of birds make them more or less susceptible to parasitism by certain tick species. Therefore, while some bird species are typically found to be intensely infested, others are relatively unaffected. This study investigated the occurrence of ticks in Passeriformes inhabiting an Atlantic Forest fragment in southeastern Brazil, during the dry and rainy seasons, by means of parasitological indexes and multiple correspondence analysis, to determine the factors that influence tick parasitism in these birds. Data were collected on 2391 ticks, all classified in the Amblyomma genus, from 589 birds. The ticks identified to the species level were A. longirostre, A. nodosum, A. calcaratum, A. parkeri, and A. ovale. Thamnophilidae, Conopophagidae, Thraupidae, Dendrocolaptidae, and Platyrinchidae were the families with the highest prevalence. In terms of parasite intensity, the families Conopophagidae, Thamnophilidae, Thraupidae, Furnariidae, and Pipridae stood out with the highest values. Bird species that are generalists regarding eating habits and habitat occupation tended to have higher parasite loads, as did larger species and those inhabiting the understory. The tick prevalence was higher in the dry season than in the rainy season. The majority of the ticks were collected from the head region, mainly around the eyes and in the nape. Also, this work reports 22 new bird-parasite relations.