New records of soft ticks (Acari: Argasidae) from caves in Brazil, with a morphological study of Ornithodoros fonsecai and an analysis of the taxonomic status of Antricola inexpectata.

In this study, we report soft ticks from bat-inhabiting caves in different areas of Brazil. From 2010 to 2019, we collected 807 tick specimens from nine caves located in four Brazilian states among two biomes. Ticks were morphologically identified as Antricola guglielmonei (282 specimens), Ornithodoros cavernicolous (260 specimens), and Ornithodoros fonsecai (265 specimens). Whereas A. guglielmonei was collected on bat guano in hot caves, O. cavernicolous and O. fonsecai were collected in cracks and crevices on the walls of cold caves, sometimes in the same chamber. Morphological identifications were corroborated by molecular and phylogenetic analyses inferred from tick mitochondrial 16S rRNA gene partial sequences. The sequences of A. guglielmonei, O. cavernicolous and O. fonsecai collected in this study clustered with conspecific GenBank sequences from different localities of Brazil. Remarkably, a clade containing 12 sequences of O. fonsecai was clearly bifurcated, denoting a degree of genetic divergence (up to 5 %) of specimens from Cerrado/Atlantic Forest biomes with the specimens from the Caatinga biome. To further evaluate this divergence, we performed morphometric analysis of the larval stage of different O. fonsencai populations by principal component analysis, which indicated that the larvae from Caatinga populations were generally smaller than the larvae from other biomes. Some of the present A. guglielmonei specimens were collected from the type locality of Antricola inexpectata. Comparisons of these specimens with the type specimens of A. inexpectata and A. guglielmonei indicated that they could not be separated by their external morphology. Hence, we are relegating A. inexpectata to a synonym of A. guglielmonei. This proposal is corroborated by our phylogenetic analysis.

A Novel Relapsing Fever Group Borrelia Isolated from Ornithodoros Ticks of the Brazilian Caatinga.

Tick-borne relapsing fever group (RFG) borreliosis remains neglected as a human disease and little is known on its maintenance in ticks and vertebrates, especially in South America. Therefore, this study investigated borrelial infection in Ornithodoros ticks collected in rodent-inhabited rock formations in the Brazilian semiarid region, within the Caatinga biome. Collected ticks (Ornithodoros rietcorreai and Ornithodoros cf. tabajara) were allowed to feed under laboratory conditions on guinea pigs, which had blood samples examined daily by dark-field microscopy. No spirochetes were visualized in the blood of any of four O. rietcorreai-infested guinea pigs. Contrastingly, spirochetes were visualized between 9 and 39 days after tick feeding in the blood of three guinea pigs, each infested with O. cf. tabajara ticks from a different locality. Guinea pig infection was confirmed by passages into experimental animals and by generating DNA sequences of Borrelia spp. from the blood of spirochetemic guinea pigs. Three O. cf. tabajara populations were infected by the same borrelial organism, which was characterized as a novel RFG agent (named as 'Candidatus Borrelia caatinga') based on 10 Borrelia loci (rrs, flaB, glpQ, gyrB, clpX, pepX, pyrG, recG, rplB and uvrA). We demonstrated that O. cf. tabajara is a competent vector of the novel Borrelia sp. isolates, although none of the infected rodents developed clinical illness.

Acaricidal efficacy and chemical study of hexane extracts of the leaves of Neoglaziovia variegata (Bromeliaceae) against the tick Rhipicephalus microplus.

The frequent use of acaricides against the tick Rhipicephalus microplus increases the risk of development of resistance. Recent studies have revealed that Neoglaziovia variegata, an indigenous plant species known in Brazil as 'caroá', has a deleterious effect against R. microplus. In the current study, extracts of N. variegata were studied for their possible acaricidal properties. A hexane extract of N. variegata leaves was fractionated in a chromatography column and the fractions were tested in adult tick immersion tests in triplicate using three concentrations (5, 10 and 25 mg/ml). All the fractions had harmful effects on the ticks. However, three fractions were more efficaceous. Phytochemical analysis indicated that stigmast-5-en-3-ol and stigmastanol were most abundant; they might be responsible for the acaricidal effects, making them potentially useful as alternative agents to control the tick R. microplus.

Anthelmintic resistance of gastrointestinal nematodes in sheep grazing in irrigated and dry areas in the semiarid region of northeastern Brazil.

This study aimed to determine the AR of gastrointestinal nematodes (GIN) to commercial drugs in sheep flocks naturally infected, grazing in irrigated (IA) and dry (DA) areas of the semiarid region in northeastern Brazil. Fecal egg count reduction tests (FECRT) were performed at 10 farms. From each flock, 36 adult sheep were selected and divided into five groups (G1 (0.08% ivermectin), G2 (10% albendazole), G3 (5% levamisole), G4 (1% moxidectin), G5 (10% closantel) and one control group, G6). All the commercial drugs were found to reduce the number of eggs per gram of feces (EPG). Resistance to ivermectin (37.1%), albendazole (52.1%), and levamisole (52.0%) was detected at all the farms, but nematodes proved to be susceptible to moxidectin (87.9%) and closantel (83.9%). The overall average efficacy of the commercial drugs was significantly higher (P < 0.05) in DA (49.2%), where moxidectin (90.4%) showed high effectiveness. The presence of the parasite Haemonchus contortus predominated at all the farms. The variables irrigated area (P = 0.002), intensive breeding (P = 0.018), uncovered enclosures (P = 0.05), cultivated (P = 0.043) and native/cultivated (P = 0.007) pastures, and rotational grazing (P = 0.013) were significantly associated with GIN infection; irrigated area (P = 0.009), semi-intensive breeding (P = 0.05), rotational grazing (P = 0.045), cultivated (P = 0.021) and native/cultivated (P = 0.04) pastures, and estimated weighing of animals (P = 0.002) were significantly associated with AR. Therefore, improved management practices and strategic deworming must be implemented to prevent the development of AR.

Ectoparasites of small mammals in a fragmented area of the southern Amazonia: interaction networks and correlations with seasonality and host sex.

The present work aimed to analyze the ectoparasite-host interaction network and possible differences of this interaction related to two seasonal periods and host sex. During November 2016 and July 2017, non-flying small mammals were captured in 17 forest fragments located in the southern portion of the Amazon biome. We captured 96 individuals belonging to 10 host species that were parasitized with a total of 3668 ectoparasites. Overall, we identified 24 ectoparasite taxa belonging to the mite and insect groups Ixodida (ticks), Mesostigmata, Sarcoptiformes, Trombidiformes (mites), Phthiraptera (lice), and Siphonaptera (fleas). The interaction network between all ectoparasites and hosts showed significant deviation from random, with moderately high specialization index (H2' = 0.80). There was seasonal difference in prevalence for Amblyomma cajennense (Fabricius) sensu stricto (s.s), Amblyomma coelebs Neumann and larvae of Amblyomma. This difference was also found in the mean intensity of infestation of Amblyomma larvae and the mite Tur aragaoi (Fonseca). Only mean intensity of infestation differed in relation to host sex for the species Marmosa constantiae Thomas. Our results demonstrate that specificity between ectoparasites and small mammals in this region is moderately high and that the pattern of aggregation of some ectoparasite taxa differed between two seasons, as well as between sexes in M. constantiae.

A high gene flow in populations of Amblyomma ovale ticks found in distinct fragments of Brazilian Atlantic rainforest.

The genetic structure of populations of the tick Amblyomma ovale from five distinct areas of the Brazilian Atlantic rainforest was evaluated via DNA sequencing and associated with the presence of domestic dogs acting as hosts at the edge of forest fragments. Ticks were collected from domestic dogs and from the environment between 2015 and 2017. Four collection areas were located in the surroundings and within the Serra do Mar State Park, São Paulo State (23°37'21"S, 45°24'43"W), where dogs were bimonthly monitored along 2 years using camera traps and GSM trackers. To determine the spatial limits of genetic structure, ticks collected upon dogs living near the Serra do Baturié, Ceará State (4°15'40"S, 38°55'54"W) were included as well. A total of 39 haplotypes of 16S rRNA and Cox 1 mitochondrial genes sequences were observed, with 27 of them coming from areas within the Serra do Mar State Park. No haplotype was shared between the Serra do Mar and the Serra do Baturié indicating isolation of tick populations at the scale of 2000 km. Although three different haplotype lineages of A. ovale occurred within the Serra do Mar State Park, no genetic structure was found across the study sites within this park, suggesting high tick gene flow across a range of 45 km. Monitoring data from domestic dogs and wild carnivores showed that these species share the same habitats at the forest edge, with dogs playing a likely limited role in tick dispersal. Our findings have important implications for understanding the genetic structure of wide spread A. ovale along Brazilian rainforest remnants, which can further be associated to tick-borne infectious agents, such as Rickettsia parkeri, and used for predicting future patterns of tick diversity in the Brazilian Atlantic rainforest.

Detection of anti-Toxoplasma gondii antibodies in small wild mammals from preserved and non-preserved areas in the Caatinga biome, a semi-arid region of Northeast Brazil.

This study was conducted to determine the seroprevalence of anti-Toxoplasma gondii antibodies in 152 free-living small wild mammals from distinct regions in the Caatinga biome, a semi-arid region in the Northeast of Brazil: the National Park of Serra das Confusões (NPSC), which is a preserved area in the state of Piauí, and the municipalities of Petrolina and Lagoa Grande, two non-preserved areas in the state of Pernambuco. Using the modified agglutination test (MAT), we found that 5.3% (4/75) and 3.3% (2/60) of small wild mammals were positive for IgG anti-T. gondii antibodies in the NPSC and Petrolina, respectively. All mammals from Lagoa Grande (0/17) tested negative on the MAT. Indirect infection of T. gondii was determined by MAT in Galea spixii, Monodelphis domestica and Thrichomys laurentius (from NPSC) and in Didelphis albiventris (from Petrolina). Seropositive animals were observed in both preserved and non-preserved areas within the Caatinga biome. Low seroprevalences observed can be related to the extreme temperature and humidity in this particular biome.

Investigação sorológica de Rickettsia rickettsii e Coxiella burnetii em caprinos e ovinos no entorno do Parque Nacional da Serra das Confusões, Piauí / Infection survey of Rickettsia rickettsii and Coxiella burnetii in sheep and goats from National Park of Serra das Confusões, Piauí

As doenças causadas por bactérias dos gêneros Rickettsia e Coxiella possuem como vetores artrópodes hematófagos, na sua maioria carrapatos, que atuam diretamente na transmissão de patógenos responsáveis por enfermidades de grande impacto na medicina veterinária e humana. O presente estudo objetivou realizar uma investigação sorológica de Rickettsia rickettsii e Coxiella burnetii em caprinos e ovinos criados no entorno do Parque Nacional da Serra das Confusões (PNSC), localizado no estado do Piauí, região nordeste do Brasil. Amostras de soro de 202 caprinos e 153 ovinos foram testadas pela Reação de Imunofluorescência Indireta (RIFI) para detecção de anticorpos anti-R. rickettsii e anti-C. burnetii, sendo consideradas positivas quando apresentaram títulos ≥ 64. Carrapatos em fase de parasitismo foram coletados e identificados. Todas as amostras de caprinos e ovinos foram soronegativas para antígenos de R. rickettsii. Foi verificado soropositividade em 2% (3/153) das amostras de ovinos para C. burnetii, com títulos variando de 64 a 4.096. As amostras de caprinos não foram reagentes ao referido antígeno. Não foi observado parasitismo em caprinos por carrapatos. No total, foram coletados 56 carrapatos parasitando 15 ovinos (9,8%), todos identificados como Rhipicephalus microplus. O estudo demonstrou a ausência de anticorpos anti-R. rickettsii nas amostras de caprinos e ovinos, ausência de anticorpos anti-C. burnetii em caprinos; e possibilitou o primeiro relato da ocorrência sorológica de C. burnetii em ovinos nesta região do Brasil.(AU)

The diseases caused by bacteria from the genera Rickettsia and Coxiella have hematophagous arthropods as vectors, mostly by ticks, which act directly on the transmission of pathogens that are responsible for diseases with major impact on veterinary and human medicine. The present study aimed to survey the infection of Rickettsia rickettsii and Coxiella burnetii in sheep and goats surrounding in the National Park of Serra das Confusões (NPSC), located in the state of Piauí, Northeast of Brazil. Serum samples from 202 goats and 153 sheep were tested by Indirect Immunofluorescence Assay (IFA) for the detection of antibodies against R. rickettsii and C. burnetii. The samples were considered positive when they showed titers ≥ 64. Ticks in parasitic stage were collected and identified. All samples from sheep and goats were seronegative for R. rickettsii. Seropositivity was verified in 2% (3/153) of the samples of sheep for C. burnetii, with titers ranging from 64 to 4096. The serum samples obtained from goats were seronegative to the above antigens. In total, 56 ticks were collected from 15 sheep (9.8%) all identified as Rhipicephalus microplus. The study demonstrated absence of infection by R. rickettsii in samples of sheep and goats, absence of infection of C. burnetii in goats; and the first report of serological occurrence of C. burnetii in sheep in this region of Brazil.(AU)

Tristeza Parasitária em bovinos do semiárido pernambucano / Cattle Tick Fever in semi-arid of Pernambuco

Este estudo objetivou determinar a soroprevalência da Babesiose e Anaplasmose em bovinos dos municípios de Ouricuri e Petrolina, estado de Pernambuco, Brasil; e definir os possíveis fatores de risco para a ocorrência dessas doenças. Amostras de sangue foram coletadas para realização de teste sorológico por Imunofluorescência Indireta (RIFI). Questionários epidemiológicos sanitários foram aplicados aos produtores com o objetivo de identificar possíveis fatores de risco. Carrapatos foram coletados, identificados e testados por Reação em Cadeia da Polimerase (PCR) para o diagnóstico da infecção por Anaplasma marginale, Babesia bigemina e Babaesia bovis. O estudo foi conduzido com 861 bovinos, sendo 468 de Petrolina e 393 de Ouricuri. A soroprevalência de A. marginale, B. bigemina e B. bovis em Petrolina foi de 35,0% (164/468), 35,9% (168/468) e 32,3% (151/468), respectivamente; e em Ouricuri foi de 45,5% (179/393), 38,6% (152/393) e 54,9% (216/393), respectivamente. A co-infecção por Anaplasma spp. e Babesia spp. foi observada em 31,6% e 32,1% de amostras de Petrolina e Ouricuri, respectivamente. A detecção de DNA de Babesia spp. por PCR foi possível em 5,8% (8/137) carrapatos, dos quais em 62,5 % (5/8) foi detectada posteriormente infecção por B. bovis, e em 23,3% (32/137) por A. marginale. A presença de carrapatos, o uso de acaricidas, idade, raça, e o município de residência dos animais foram identificados como fatores de risco para TPB pela análise univariável e multivariável. Este estudo permitiu caracterizar os municípios estudados como de instabilidade enzoótica para esses hemoparasitos, e consequentemente, alertar para adoção de medidas adequadas de controle e realização de novos estudos.(AU)

This study aimed to determine the seroprevalence of Babesiosis and Anaplasmosis in cattle from the municipalities of Ouricuri and Petrolina, state of Pernambuco, Brazil, and to define the risk factors for the occurrence of the diseases. Blood samples were collected for serologic testing by Indirect Immunofluorescence Assay (IFA). Sanitary epidemiological questionnaires were applied to the producers aiming to identify possible risk factors. Ticks were collected, identified and tested by Polymerase Chain Reaction (PCR) for the diagnosis of infection by Anaplasma marginale, Babesia bigemina and Babesia bovis. The study was conducted with 861 cattle, being 468 in Petrolina and 393 in Ouricuri. The seroprevalence of A. marginale, B. bigemina and B. bovis in Petrolina was of 35.0% (164/468), 35.9% (168/468) and 32.3% (151/468), respectively; and in Ouricuri was 45.5% (179/393), 38.6% (152/393), and 54.9% (216/393), respectively. Co-infection for Anaplasma spp. and Babesia spp. was observed in 31.6% and 32.1% samples of Petrolina and Ouricuri, respectively. The detection of DNA of Babesia spp. by PCR was possible in 5.8% (8/137) ticks; which 62.5% (5/8) was detected later infection with B. bovis; and 23.3% (32/137) with A. marginale. The presence of ticks, the use of acaricide, age, race, and county of residence of the animals were identified as risk factors for TBD by univariate analysis and multivariate. This study allowed the characterization of the municipalities studied as enzootic instability areas for these hemoparasitic, and consequently alert for adoption of adequate control measures and new studies.(AU)

Tristeza Parasitária em bovinos do semiárido pernambucano / Cattle Tick Fever in semi-arid of Pernambuco

This study aimed to determine the seroprevalence of Babesiosis and Anaplasmosis in cattle from the municipalities of Ouricuri and Petrolina, state of Pernambuco, Brazil, and to define the risk factors for the occurrence of the diseases. Blood samples were collected for serologic testing by Indirect Immunofluorescence Assay (IFA). Sanitary epidemiological questionnaires were applied to the producers aiming to identify possible risk factors. Ticks were collected, identified and tested by Polymerase Chain Reaction (PCR) for the diagnosis of infection by Anaplasma marginale, Babesia bigemina and Babesia bovis. The study was conducted with 861 cattle, being 468 in Petrolina and 393 in Ouricuri. The seroprevalence of A. marginale, B. bigemina and B. bovis in Petrolina was of 35.0% (164/468), 35.9% (168/468) and 32.3% (151/468), respectively; and in Ouricuri was 45.5% (179/393), 38.6% (152/393), and 54.9% (216/393), respectively. Co-infection for Anaplasma spp. and Babesia spp. was observed in 31.6% and 32.1% samples of Petrolina and Ouricuri, respectively. The detection of DNA of Babesia spp. by PCR was possible in 5.8% (8/137) ticks; which 62.5% (5/8) was detected later infection with B. bovis; and 23.3% (32/137) with A. marginale. The presence of ticks, the use of acaricide, age, race, and county of residence of the animals were identified as risk factors for TBD by univariate analysis and multivariate. This study allowed the characterization of the municipalities studied as enzootic instability areas for these hemoparasitic, and consequently alert for adoption of adequate control measures and new studies.

Este estudo objetivou determinar a soroprevalência da Babesiose e Anaplasmose em bovinos dos municípios de Ouricuri e Petrolina, estado de Pernambuco, Brasil; e definir os possíveis fatores de risco para a ocorrência dessas doenças. Amostras de sangue foram coletadas para realização de teste sorológico por Imunofluorescência Indireta (RIFI). Questionários epidemiológicos sanitários foram aplicados aos produtores com o objetivo de identificar possíveis fatores de risco. Carrapatos foram coletados, identificados e testados por Reação em Cadeia da Polimerase (PCR) para o diagnóstico da infecção por Anaplasma marginale, Babesia bigemina e Babaesia bovis. O estudo foi conduzido com 861 bovinos, sendo 468 de Petrolina e 393 de Ouricuri. A soroprevalência de A. marginale, B. bigemina e B. bovis em Petrolina foi de 35,0% (164/468), 35,9% (168/468) e 32,3% (151/468), respectivamente; e em Ouricuri foi de 45,5% (179/393), 38,6% (152/393) e 54,9% (216/393), respectivamente. A co-infecção por Anaplasma spp. e Babesia spp. foi observada em 31,6% e 32,1% de amostras de Petrolina e Ouricuri, respectivamente. A detecção de DNA de Babesia spp. por PCR foi possível em 5,8% (8/137) carrapatos, dos quais em 62,5 % (5/8) foi detectada posteriormente infecção por B. bovis, e em 23,3% (32/137) por A. marginale. A presença de carrapatos, o uso de acaricidas, idade, raça, e o município de residência dos animais foram identificados como fatores de risco para TPB pela análise univariável e multivariável. Este estudo permitiu caracterizar os municípios estudados como de instabilidade enzoótica para esses hemoparasitos, e consequentemente, alertar para adoção de medidas adequadas de controle e realização de novos estudos.

A new argasid tick species (Acari: Argasidae) associated with the rock cavy, Kerodon rupestris Wied-Neuwied (Rodentia: Caviidae), in a semiarid region of Brazil.

BACKGROUND: The rock cavy Kerodon rupestris (Wied-Neuwied, 1820) is a rodent species endemic to northeastern Brazil. Earlier studies have associated the argasid tick Ornithodoros talaje (Guérin-Méneville, 1849) with rocky cavy; however, a recent study proposed that O. talaje is not established in Brazil, where previous reports of this species were possibly misidentifications of closely related species, yet to be properly determined. Here, we describe a new species of Ornithodoros Koch, 1844 associated with rock cavies in northeastern Brazil. METHODS: During 2012-2013, Ornithodoros ticks were collected from K. rupestris resting places in Paraíba State (PB) and Piauí State (PI), northeastern Brazil. These ticks were brought alive to the laboratory, and used to form two laboratory colonies (PB and PI ticks). Field-collected adults and laboratory-reared larvae were used for morphological description through light and scanning electron microscopy. DNA sequences of the mitochondrial 16S rRNA gene were generated from nymphal ticks and used to conduct phylogenetic analyses along with other Ornithodoros spp. sequences from GenBank. Reproductive compatibility of crosses between PB and PI adult ticks was evaluated, as well as analyses of hybrid ticks through larval morphology by a principal components analysis (PCA) and DNA sequences of the second internal transcribed spacer (ITS2) region from adult ticks. RESULTS: Morphological analysis allowed recognizing these ticks as a new species, Ornithodoros rietcorreai n. sp. The larva of O. rietcorreai is distinct from those of other Ornithodoros spp. by the combination of the following character states: 14 pairs of dorsal setae, dorsal plate pyriform, hypostome with pointed apex and dental formula 3/3 anteriorly, 2/2 posteriorly, and anal valves with long and pointed leaf-shaped ends. There were a few larval morphological differences between PB and PI ticks, and their mitochondrial 16S rDNA sequences diverged by 3.3 %. On the other hand, cross-mating experiments showed that PB and PI ticks were reproductive compatible, indicating that they represent a single species. Analyses of ITS2 sequences and PCA corroborated this assumption. CONCLUSION: Ornithodoros rietcorreai is described as a new species associated with K. rupestris in Brazil, increasing the Brazilian tick fauna to 70 species.

Isolation of the Pathogen Rickettsia sp. Strain Atlantic Rainforest From Its Presumed Tick Vector, Amblyomma ovale (Acari: Ixodidae), From Two Areas of Brazil.

In this study, Amblyomma ovale Koch ticks were collected from domestic dogs in two localities of the Atlantic rainforest biome of Brazil: 1) the Paty Valley of the Chapada Diamantina National Park, Bahia state (northeastern Brazil), and 2) Adrianópolis, Paraná state (southern Brazil). Ticks were screened for the presence of Rickettsia-like structures by the hemolymph test with Giménez staining, and then processed for isolation of rickettsiae in Vero cell culture by the shell-vial technique. Rickettsiae were isolated from one A. ovale tick of each of the two localities. The two isolates were successfully established in the laboratory with several passages, each one reaching >90% infection of the cells. The two isolates were identified as the spotted fever group (SFG) agent Rickettsia sp. strain Atlantic rainforest, as their gltA (350 bp), ompB (781 bp), and ompA (567 bp) gene fragments were 100% equal to GenBank corresponding sequences of the original strain Atlantic rainforest, reported to be infecting a human in southeastern Brazil, and also 100% equal to the available ompA sequence of strain Bahia, reported to be infecting a human in Paty Valley, the same area of the present study in Bahia state. Ten dogs from Paty Valley were serologically tested against rickettsial antigens by the indirect immunofluorescence antibody test. At least 60% of them were seroreactive to SFG rickettsiae. The role of A. ovale as vector of Rickettsia sp. strain Atlantic rainforest in the Paty Valley area, as well as in other parts of Latin America, is discussed.

Geographical distribution of Amblyomma cajennense (sensu lato) ticks (Parasitiformes: Ixodidae) in Brazil, with description of the nymph of A. cajennense (sensu stricto).

BACKGROUND: Until recently, Amblyomma cajennense (Fabricius, 1787) was considered to represent a single tick species in the New World. Recent studies have split this taxon into six species. While the A. cajennense species complex or A. cajennense (sensu lato) (s.l.) is currently represented by two species in Brazil, A. cajennense (sensu stricto) (s.s.) and Amblyomma sculptum Berlese, 1888, their geographical distribution is poorly known. METHODS: The distribution of the A. cajennense (s.l.) in Brazil was determined by morphological examination of all lots of A. cajennense (s.l.) in two large tick collections of Brazil, and by collecting new material during three field expeditions in the possible transition areas between the distribution ranges of A. cajennense (s.s.) and A. sculptum. Phylogenetic analysis inferred from the ITS2 rRNA gene was used to validate morphological results. Morphological description of the nymphal stage of A. cajennense (s.s.) is provided based on laboratory-reared specimens. RESULTS: From the tick collections, a total 12,512 adult ticks were examined and identified as 312 A. cajennense (s.s.), 6,252 A. sculptum and 5,948 A. cajennense (s.l.). A total of 1,746 ticks from 77 localities were collected during field expeditions, and were identified as 249 A. cajennense (s.s.), 443 A. sculptum, and 1,054 A. cajennense (s.l.) [these A. cajennense (s.l.) ticks were considered to be males of either A. cajennense (s.s.) or A. sculptum]. At least 23 localities contained the presence of both A. cajennense (s.s.) and A. sculptum in sympatry. DNA sequences of the ITS2 gene of 50 ticks from 30 localities confirmed the results of the morphological analyses. The nymph of A. cajennense (s.s.) is morphologically very similar to A. sculptum. CONCLUSION: Our results confirmed that A. cajennense (s.l.) is currently represented in Brazil by only two species, A. cajennense (s.s.) and A. sculptum. While these species have distinct distribution areas in the country, they are found in sympatry in some transition areas. The current distribution of A. cajennense (s.l.) has important implications to public health, since in Brazil A. sculptum is the most important vector of the bacterium Rickettsia rickettsii, the etiological agent of Brazilian spotted fever.

Epidemiological aspects and risk factors for infection by Leishmania infantum chagasi in dogs from municipality of Petrolina, Northeastern Brazil.

Visceral leishmaniasis (VL) is a disease of great concern for public health because of its high incidence and lethality. Here, we performed a serologic study of domestic dogs in the municipality of Petrolina in northeastern Brazil to evaluate the possible risk factors associated with canine seropositivity for Leishmania infantum chagasi. Blood samples from 1245 dogs in urban and rural areas were collected and examined by indirect immunofluorescent antibody test (IFAT) and an indirect enzyme-linked immunosorbent assay (ELISA). The dogs were subjected to physical examination and classified according to their clinical manifestations. A questionnaire was administered to the owners to detect potential risk factors for infection with Leishmania spp. using logistic regression models. Of the 1245 dogs evaluated, 11.2% (140/1245) were seropositive in both tests (CI 95%: 9.5% to 13.1%). Approximately 60.7% of the reactive dogs were clinically suspect, with lymphadenomegaly, cutaneous ulcerations, onychogryphosis, pale mucous membranes and alopecia being the most obvious symptoms of infection. The seroprevalences in urban and rural areas were 5.4% (CI 95%: 4% to 7.1%) and 23.6% (CI 95%: 19.5% to 28.1%), respectively. The possible risk factors for the presence of anti L. infantum chagasi antibodies were the presence of a green area close to the home of the animal (OR=3.63; p<0.001), a mongrel breed (OR=2.11; p=0.025) and male gender (OR=1.51, p=0.034). The seroprevalence of L. infantum chagasi in the canine population is distributed in a heterogeneous manner, with a higher prevalence in rural areas.

Seroprevalence of anti-Toxoplasma gondii and anti-Neospora caninum antibodies in domestic mammals from two distinct regions in the semi-arid region of Northeastern Brazil.

The study was conducted to determine the seroprevalence of anti-Toxoplasma gondii and anti-Neospora caninum antibodies in goats, sheep, dogs and cats from two distinct regions in the semi-arid region of Northeastern Brazil: Serra das Confusões National Park (SCNP), a preserved area; and municipality of Petrolina, a non-preserved area. Overall, by the indirect fluorescent antibody test (IFAT), the prevalence for IgG anti-T. gondii antibodies in goats was 5.1% (19/376) and 2.4% (9/376); in sheep, it was 10.2% (34/332) and 14.2% (47/332); in dogs, it was 19.7% (25/127) and 3.9% (5/127) and, in cats, it was 25.7% (9/35) and 5.7% (5/35), for T. gondii and N. caninum, respectively. For T. gondii infection, the risk factors associated with the seroprevalence was gender (female) and study area (Petrolina) for goats and only the study area (Petrolina) for dogs; and for N. caninum infection the risk factors were the age (six months to one year) and the study area (Petrolina) for sheep. The circulation of T. gondii and N. caninum was observed in both areas, with significative risk factors demonstrated of a degraded environment.

Ectoparasite Infestations and Canine Infection by Rickettsiae and Ehrlichiae in a Semi-Arid Region of Northeastern Brazil.

This study investigated the prevalence of Rickettsia spp. and Ehrlichia canis infection in dogs and their ectoparasites from rural and urban areas of two municipalities, Petrolina and Juazeiro, within a semiarid region (Caatinga biome) of northeastern Brazil, by immunofluorescence assay (IFA) and polymerase chain reaction (PCR). Overall, 12.1% (61/504) and 23.0% (116/504) of canine plasma samples had antibodies reactive to Rickettsia spp. and E. canis. E. canis DNA was detected by PCR in 8.3% (42/504) of canine blood samples, whereas no blood sample was positive for Rickettsia spp. The infection by E. canis was determined by PCR in 4.9% (14/285) Rhipicephalus sanguineus sensu lato (s.l.) ticks and by Rickettsia felis in 1.1% (3/285) and 40.6% (74/182) ticks and fleas, respectively. Multivariate regression analyses revealed that canine seropositivity to Rickettsia spp. was associated statistically with the variables "to reside in Petrolina" and "presence of ectoparasites." Our results indicate that canine infection by E. canis might be endemic in the Caatinga biome as it is in other Brazilian biomes. Although no previous serosurvey for Rickettsia spp. has been conducted on dogs from the Caatinga biome, our values are much lower than the ones reported for rural dogs from other Brazilian biomes. These differences are likely related to the semiarid climate of the aatinga biome, which minimizes the exposure of rural dogs to Amblyomma spp. ticks, the most common vectors of Rickettsia spp. in Brazil. Considering that dogs are excellent sentinels for human exposure to Rickettsia spp., we can infer that the risks of human acquiring tick-borne rickettsiosis in the Caatinga region of the present study are low. The rickettsial infection rates in fleas and ticks were not related to canine seropositivity; i.e., areas with higher Rickettsia infection rates in fleas had the lowest canine seroreactivity to Rickettsia spp.

Rickettsia bellii in Amblyomma rotundatum ticks parasitizing Rhinella jimi from northeastern Brazil.

This study evaluated rickettsial infection in Amblyomma rotundatum ticks collected from toads (Rhinella jimi) in the Brazilian Caatinga biome, an unique semiarid region of South America. Tick infestations were observed in 57.8% toads (26/45); mean infestation: 1.6 ticks/toad. DNA extraction from 42 ticks (6 larvae, 22 nymphs and 11 female adults) was tested by polymerase chain reaction (PCR) targeting Rickettsia organisms, which were detected in 100% of the ticks. Amplicons' DNA sequences were identical to each other and 99% identical to Rickettsia bellii from GenBank. DNA samples extracted from the blood of the 45 toads were negative by rickettsia-PCR protocols.

Babesia canis vogeli infection in dogs and ticks in the semiarid region of Pernambuco, Brazil / Infecção por Babesia canis vogeli em cães e carrapatos de uma região semiárida de Pernambuco

This study aimed to report the prevalence of Babesia canis vogeli in dogs and ticks in the urban and rural areas of Petrolina, Pernambuco. Serum and peripheral blood samples of 404 dogs were tested by indirect immunofluorescence assay (IFA) and by blood smears, respectively. The presence of tick infestation was evaluated, and some specimens were submitted to DNA amplification by polymerase chain reaction (PCR). The presence of antibodies anti-B. canis vogeli was determinate in 57.9% (234/404) of dogs. The direct detection of Babesia spp was obtained in 0.5% (2/404) dogs by visualization of intraerythrocytic forms. Infestation by Rhipicephalus sanguineus sensu lato was observed in 54.5% (220/404) of dogs in both urban and rural areas. DNA of Babesia canis vogeli were obtained by PCR in 6% individual (3/50) and 8.7% of pool of ticks (7/80). The risk factors for the presence of anti-B. canis vogeli antibodies, as determined through the application of logistic regression models (P<0.05), were the following: medium breed size variables (P<0.001); contact with areas of forest (P=0.021); and access on the street (P=0.046). This study describes, for the first time, the confirmation of infection of B. canis vogeli in dogs and ticks in the semiarid region of Pernambuco, Brazil.

Este trabalho objetivou avaliar a prevalência de Babesia canis vogeli em cães e carrapatos de áreas urbanas e rurais do município de Petrolina, Pernambuco, Nordeste do Brasil. Amostras de soro e sangue periférico de 404 cães foram testadas pela Reação de Imunoflorescência Indireta (RIFI), e por esfregaço sanguíneo. A presença de infestação por carrapatos foi avaliada, e alguns espécimes foram submetidos à amplificação do DNA pela Reação em Cadeia pela Polimerase (PCR). A presença de anticorpos anti-B. canis vogeli foi determinada em 57,9% (234/404) dos cães. A soroprevalência em áreas urbanas e rurais foi 48,5% e 67,3%, respectivamente. A detecção direta de Babesia spp foi obtida em 0,5% dos cães pela visualização de formas intraeritrocitárias. A infestação pelo carrapato Rhipicephalus sanguineus foi observada em 54,5% (220/404) dos cães. DNA de Babesia canis vogeli obtido pela PCR foi 6% (3/50) em carrapatos processados individualmente e 8,7% (7/80) em pools. Os fatores de risco para presença de anticorpos anti- B. canis vogeli utilizando modelo de regressão logística (P < 0,05) foram porte médio (P <0,001), contato com áreas de floresta (P = 0,021), e acesso dos cães à rua (P = 0,046). Este estudo descreve pela primeira vez a confirmação da infecção de Babesia canis infectando cães e carrapatos em uma região semiárida de Pernambuco, Brasil.

Occurrence of antibodies against Toxoplasma gondii and its isolation and genotyping in donkeys, mules, and horses in Brazil.

The occurrence of antibodies against Toxoplasma gondii was determined in donkeys, mules, and horses from different regions of Brazil. Serum samples from 304 donkeys (67.11%), 118 horses (26.05%), and 31 mules (6.84%) were analyzed by means of the indirect fluorescent antibody test (cutoff=64). Antibodies against T. gondii were detected in 129 equids (28.47%) (82 donkeys, 32 horses, and 15 mules). Tissue samples from 19 seropositive and 50 seronegative animals were obtained in order to isolate the parasite by means of mouse bioassay, and T. gondii was isolated from a donkey. Through genotypic characterization of the isolate, by means of polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) using 11 genotypic markers, the genotype #163 (TgCkBr220), which has already been described in chickens in Brazil, was identified.

A novel Ehrlichia genotype strain distinguished by the TRP36 gene naturally infects cattle in Brazil and causes clinical manifestations associated with ehrlichiosis.

A novel Ehrlichia genotype most closely related to E. canis was reported in North American cattle in 2010, and a similar agent was subsequently identified in the hemolymph of Brazilian Rhipicephalus (Boophilus) microplus ticks and isolated in 2012. The purpose of this study was to determine whether this or other novel ehrlichial agents naturally infect Brazilian cattle. Using PCR targeting the genus-conserved dsb gene, DNA from this novel ehrlichial agent in Brazilian cattle was detected. Attempts to isolate the organism in vitro were performed using DH82 cells, but morulae and ehrlichial DNA could only be detected for approximately one month. In order to further molecularly characterize the organism, PCR was performed using primers specific for multiple E. canis genes (dsb, rrs, and trp36). Sequence obtained from the conserved rrs and dsb genes demonstrated that the organism was 99-100% identical to the novel Ehrlichia genotypes previously reported in North American cattle (rrs gene) and Brazilian ticks (rrs and dsb genes). However, analysis of the trp36 gene revealed substantial strain diversity between these Ehrlichia genotypes strains, including divergent tandem repeat sequences. In order to obtain preliminary information on the potential pathogenicity of this ehrlichial agent and clinical course of infection, a calf was experimentally infected. The calf showed clinical signs of ehrlichiosis, including fever, depression, lethargy, thrombocytopenia, and morulae were observed in peripheral blood monocytes. This study reports a previously unrecognized disease-causing Ehrlichia sp. in Brazilian cattle that is consistent with the genotype previously described in North America cattle and ticks from Brazil. Hence, it is likely that this is the organism previously identified as Ehrlichia bovis in Brazil in 1982. Furthermore, we have concluded that strains of these Ehrlichia genotypes can be molecularly distinguished by the trp36 gene, which has been widely utilized to define E. canis strain diversity.