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Borrelia theileri is a relapsing fever group Borrelia that is transmitted to cattle by ticks of the genus Rhipicephalus. In this study, we describe the first molecular detection of B. theileri subclinical infection in a cow in Brazil. During the examination of stained blood smears of 10 cows from a farm with a recent history of fatal Trypanosoma vivax trypanosomiasis, spirochete-like structures were incidentally detected in one of the cows. The animal presented good body score, normal hematocrit and normal-colored ocular mucosa. Temperature, heart rate and respiratory rate were all normal. The animal was infested by ticks, which were morphologically identified as Rhipicephalus microplus. The diagnosis was confirmed by testing DNA extracted from a blood sample using a PCR targeting a ≈ 650 bp fragment of the flagellin B (flaB) gene of Borrelia spp. The partial flaB sequence obtained showed 99.83% similarity with B. theileri. Phylogenetically, the flaB partial sequence generated herein clustered with other B. theileri sequences, being separated from B. lonestari. This is the first molecular detection of B. theileri subclinical infection in a cow in Brazil. The possible implications of this finding are discussed.

This is the first report of Babesia vogeli molecular detection in dogs from the state of Acre, northern Brazil. This study aimed to perform the molecular detection of Babesia vogeli in dogs in the municipality of Rio Branco, Acre. Blood samples were collected from 47 dogs presenting with clinical signs comparable to hemoparasitosis. These were dogs which were attended in veterinary clinics from Rio Branco municipality, Acre. Physical examinations, packed cell volume (PCV) determination, platelet number estimation, hemoparasite investigation in the blood (collected from the pinna and peripheral blood), and polymerase chain reaction (PCR) for piroplasm based on the 18S rRNA gene, were performed. One dog (1/47, 2.1%; CI 95%: 0.1-11.3%) tested positive to Babesia vogeli in the polymerase chain reaction (PCR) assay for piroplasms and the resulting sequence showed 100% identity with Babesia vogeli isolates deposited in GenBank®. Co-infection with Ehrlichia spp. was also observed by direct examination (via blood smear). The clinical and hematological alterations observed in the positive animal were anorexia, dehydration, white mucous membranes, anemia and thrombocytopenia. Este é o primeiro relato de detecção molecular de Babesia vogeli em cães do estado do Acre, norte do Brasil. Este estudo teve como objetivo realizar a detecção molecular de B. vogeli em amostras de sangue de 47 cães com sinais clínicos compatíveis com hemoparasitoses no município de Rio Branco, Acre. Tratavam-se de animais atendidos em clínicas veterinárias do município, sendo realizados exames físicos, determinação do volume globular (VG), estimativa do número de plaquetas, investigação de hemoparasitos no sangue (coletado da ponta da orelha e sangue periférico). Além disso, amostras de sangue foram submetidas a extração de DNA e reação em cadeia da polimerase (PCR) para amplificação de fragmentos do gene 18S rRNA de piroplasmas. Um cão (1/47, 2,1%; IC 95%: 0,1-11,3%) apresentou resultado positivo para B. vogeli na PCR para piroplasmas e a sequência resultante mostrou 100% de identidade com os isolados de B. vogeli depositados no GenBank®. Co-infecção com Ehrlichia spp. também foi observado por exame direto (esfregaço de sangue). As alterações clínicas e hematológicas observadas no animal positivo foram anorexia, desidratação, mucosas pálidas, anemia e trombocitopenia.

Tick-borne pathogens belong to one of the two main groups of occupational biohazards, and occupational exposure to such agents puts soldiers at risk of zoonotic infections, such as those caused by rickettsiae. There are few studies on acarological fauna and occupational risk in military areas in Brazil. Thus, the present study aimed to analyze the diversity of ticks present in the military training areas of municipalities in the Southeast Region of Brazil. The ticks were collected from the selected areas using the dragging and flagging techniques as well as by visual detection on the operators’ clothing, and environmental information was also recorded. A total of ten species were collected from the 66 surveyed areas, belonging to five genera and nine species: Amblyomma sculptum, Amblyomma dubitatum, Amblyomma brasiliense, Amblyomma longirostre, Amblyomma aureolatum, Dermacentor nitens, Rhipicephalus spp., Ixodes spp. and Haemaphysalis spp. The frequent presence of tick species in military training areas along with traces and sightings of wild animals, most commonly capybaras (Hydrochoerus hydrochaeris), in most of the studied areas, indicates high levels of exposure of the military to tick vectors of spotted fever group rickettsiae and the possible occurrence of infections among the troops. Resumo As doenças transmitidas por carrapatos estão entre os dois principais grupos de riscos biológicos ocupacionais. Tal exposição ocupacional de militares os colocam sob maior risco de adquirirem doenças zoonóticas, como infecções rickettsiais, entre outras. No Brasil, há raros estudos sobre fauna acarológica e o risco ocupacional em áreas militares. Neste sentido, o presente estudo teve por objetivo analisar a diversidade de carrapatos presentes em áreas de treinamento militar de municípios da região Sudeste do Brasil. Os carrapatos foram coletados nas áreas através de arrasto de flanela, bandeiramento e/ou coleta nas vestimentas do operador, sendo registradas também informações ambientais. Das 66 áreas pesquisadas, foram coletados 9.374 carrapatos, com uma diversidade de cinco gêneros, distribuídos em dez espécies: Amblyomma sculptum, Amblyomma dubitatum, Amblyomma brasiliense, Amblyomma longirostre, Amblyomma aureolatum, Amblyomma spp., Dermacentor nitens, Rhipicephalus spp., Ixodes spp. e Haemaphysalis spp. A presença frequente de espécies de carrapatos nas áreas de instrução militar, associada aos vestígios e à presença de animais silvestres, mais comumente de capivaras na maioria das áreas estudadas, evidencia uma grande exposição dos militares a carrapatos vetores de rickettsias do Grupo da Febre Maculosa e a possível ocorrência de casos humanos nas tropas.

From a previous large epidemiological survey, we randomly selected 474 serum samples (463 horses and 11 mules) distributed among four municipalities of Pará state, Amazon region, Brazil, and from three types: farm animal, urban carthorse, and sport horse. Samples were tested by indirect fluorescence antibody test (IFAT ≥ 64) for antibodies reactive to spotted fever group (SFG) rickettsiae using Rickettsia rickettsii as crude antigens. From the 474 equids tested, 149 (31.4%) had ticks attached during sampling, belonging mostly to the species Dermacentor nitens. The overall seroprevalence for SFG rickettsiae was 31.4% (95% confidence interval: 27.3-35.9%) with 149 seropositive animals out of 474 screened. Notably, 77 equids (16.2%) had high endpoint titers ranging from 512 to 16,384, indicating that they had been exposed to SFG rickettsiae not long before sampling. Animal type affected rickettsial seroprevalence, with significantly higher values among farm horses when compared with urban and sport animals. Presence of dogs and tick infestation were negatively associated with equid seropositivity to R. rickettsii. This is the first report of SFG rickettsiae-reactive antibodies in equids from Pará state, Brazilian Amazon.

The bacterium Rickettsia rickettsii is the etiological agent of Brazilian spotted fever (BSF), and its most important vector to humans in Brazil is the tick Amblyomma sculptum. Capybaras are the main hosts of A. sculptum in many BSF-endemic areas and are considered valuable sentinels for BSF surveillance. This study aimed to assess the persistence of anti-R. rickettsii antibodies for long periods in capybaras and their passive transfer to offspring. For this purpose, three adult capybaras previously exposed to multiple infections with R. rickettsii were followed up until 3.1 years after their last exposure. During the study, one female delivered five cubs, of which three survived. Blood samples were collected monthly from adults and infants, and serum samples were titrated by indirect immunofluorescence assay (IFA) to determine endpoint titers of anti-R. rickettsii antibodies. All three adults remained seroreactive to R. rickettsii with high endpoint titers until the end of the study. All infants were seroreactive to R. rickettsii after birth and remained seroreactive for one to four months. This study showed that exposure of capybaras to R. rickettsii-infected A. sculptum ticks elicits a persistent antibody response. In addition, there was evidence of passive transfer of R. rickettsii-reactive antibodies to offspring. Resumo A bactéria Rickettsia rickettsii é o agente etiológico da febre maculosa brasileira (FMB), cujo principal vetor no Brasil é o carrapato Amblyomma sculptum. As capivaras, principais hospedeiros para A. sculptum em muitas áreas endêmicas para FMB, são consideradas valiosas sentinelas para a vigilância da FMB. Este estudo objetivou avaliar a persistência de anticorpos anti-R. rickettsii por longos períodos em capivaras e sua transferência passiva para a prole. Três capivaras adultas, previamente expostas a múltiplas infecções por R. rickettsii, foram acompanhadas até 3,1 anos após sua última exposição. Durante o estudo, uma fêmea deu à luz cinco filhotes, dos quais três sobreviveram. Amostras de soro sanguíneo foram coletadas mensalmente dos adultos e filhotes e foram tituladas por reação de imunofluorescência indireta (RIFI), para determinar os títulos finais de anticorpos anti-R. rickettsii. Os três adultos permaneceram sororreagentes para R. rickettsii com títulos elevados até o final do estudo. Todos os filhotes foram sororreagentes para R. rickettsii, após o nascimento e permaneceram sororreagentes durante um a quatro meses. Este estudo mostrou que a exposição de capivaras a carrapatos A. sculptum, infectados com R. rickettsii provoca uma resposta persistente de anticorpos. Além disso, houve evidência de transferência passiva de anticorpos anti-R. rickettsii para a prole.

Reliable data on distributional ranges of soft ticks (Argasidae) and assessments of putative tick-borne agents enhance the understanding on tick-associated microorganisms. A total of 96 ticks morphologicaly and molecularly identified as Ornithodoros rietcorreai were collected in Tocantins State, Brazil, using Noireau traps with living bait as CO2 source. Ninety-six ticks (54 nymphs, 32 males, 10 females) with different engorgement degrees were collected. Fourty-seven (48.9%) of them were individually screened by PCR for detecting bacteria of Anaplasmataceae family and genera Rickettsia, and Borrelia. The presence of protozoans of the genus Babesia was assessed as well. Fourty seven ticks were submitted to analysis. Nine ticks (19.1%) yielded sequences for gltA and htrA genes most identical with a series of endosymbiont rickettsiae and Rickettsia bellii, respectively. Upon two ticks (4.2%) we retrieved DNA of a potential new Wolbachia sp., and DNA of a putative novel Hepatozoon was characterized from three (6.4%) specimens. No DNA of Babesia or Borrelia was detected. Remarkably, amplicons of unidentified eukaryotic organisms, most closely related with apicomplexans but also with dinoflagellates (91% of identity after BLAST analyses), were recovered from two ticks (4.2%) using primers designed for Babesia 18S rRNA gene. Our records expand the distribution of O. rietcorreai into Brazilian Cerrado biome and introduce the occurrence of microorganisms in this tick species.

RESUMO A febre maculosa brasileira (FMB), descrita inicialmente nos Estados Unidos como febre maculosa das Montanhas Rochosas, é uma antropozoonose relatada apenas no continente americano e causada pela bactéria Rickettsia rickettsii. No Brasil a transmissão ocorre sobretudo pela picada de carrapatos do gênero Amblyomma spp. A doença foi inicialmente descrita como de transmissão em áreas rurais e silvestres, no entanto áreas periurbanas e urbanas vêm apresentando casos, principalmente relacionados com a presença de humanos residindo em pequenos fragmentos de mata ciliar. O presente estudo teve por objetivo elucidar a dispersão da FMB nas proximidades dos reservatórios Guarapiranga e Billings, na cidade de São Paulo, SP. Para tanto, a presença de anticorpos anti-R. rickettsii, Rickettsia parkeri e Rickettsia bellii foi avaliada em cães atendidos nas campanhas de esterilização cirúrgica e residentes ao redor dos reservatórios. Foram coletadas amostras de 393 cães, e as amostras de soro foram analisadas pela reação de imunofluorescência indireta (RIFI), com ponto de corte de 1:64. Os títulos para R. rickettsii variaram de 256 a 4096, com positividade de 3,3% (13/393); para R. bellii, de 128 a 1024 e 4,1% (16/393) de positivos, e um único animal (0,25%) foi soropositivo para R. parkeri, com título de 128. Os achados permitem concluir que a região de estudo apresenta condições de se tornar uma possível área com casos de FMB, pois comporta fragmentação de Mata Atlântica, condições essas ideais para a manutenção do vetor do gênero Amblyomma já descrito na região, bem como para a presença da Rickettsia rickettsii circulante entre os cães, confirmada pela existência de anticorpos. Condutas referentes à conscientização da população por meio de trabalhos educacionais devem ser implantadas para a prevenção da doença na população da área. ABSTRACT Brazilian Spotted Fever (BSF), initially described in the United States as Rocky Mountain Spotted Fever, is an anthropozoonosis reported only in the Americas and caused by the bacterium Rickettsia rickettsii. In Brazil, transmission occurs mainly through tick bites of the genus Amblyomma spp. The disease was initially described as transmission of rural and wild areas; however, peri-urban and urban areas have been presenting cases, mainly related to the presence of humans residing in small fragments of riparian forest. The present study aimed to elucidate the dispersal of BSF near the Guarapiranga and Billings Reservoirs, in the city of São Paulo, SP. The presence of anti-R. rickettsii, Rickettsia parkeri and Rickettsia bellii antibodies were evaluated in dogs treated in surgical sterilization campaigns and residents around the Reservoirs. Samples were collected from 393 dogs and serum samples were analyzed by indirect immunofluorescence reaction (RIFI) with a cutoff of 1:64. The titles for R. rickettsii varied from 256 to 4096 with a positivity of 3.3% (13/393); for R. bellii from 128 to 1024 and 4.1% (16/393) of positive and a single animal (0.25%) was seropositive for R. parkeri with a titre of 128. The findings allow us to conclude that the study region has conditions to become a possible area with BSF cases, as it involves Atlantic Forest, ideal conditions for the maintenance of the vector of the genus Amblyomma already described in the region and the presence of circulating Rickettsia rickettsii among dogs, confirmed by the presence of antibodies. Conducts regarding the awareness of the population through educational work should be implemented to prevent the disease in the population of the area.

Tick-borne rickettsial pathogens (TBRP) are important causes of infections in both dogs and humans. Dogs play an important role as a biological host for several tick species and can serve as sentinels for rickettsial infections. Our aim was to determine the presence of TBRP in dogs and in dog-associated ticks and their potential risk to human diseases in Medellin, Colombia. DNA for E. canis (16S rRNA and dsb) and A. platys (groEl) was detected in 17.6% (53/300) and 2.6% (8/300) of dogs, respectively. Antibodies against Ehrlichia spp. 82 (27.3%) and Anaplasma spp. 8 (2.6%) were detected in dogs. Antibody reactivity against both agents were found in 16 dogs (5.3%). Eight dogs showed antibody for Rickettsia spp. with titers that suggest 3 of them had a probable exposure to R. parkeri. Rhipicephalus sanguineus s.l. (178/193) was the main tick in dogs, followed by R. microplus (15/193). The minimum infection rates (MIR) in R. sanguineus were 11.8% for E. canis and 3.4% for A. platys. E. canis and A. platys are the main TBRP infecting dogs and ticks and R. sanguineus s.l. is likely involved in the transmission of both agents. Interestingly, we found serological evidence of exposure in dogs for spotted fever group rickettsiae. Resumo As riquétsias transmitidas por carrapatos (RTC) são causas importantes de infecção em cães e humanos. Os cães exercem um papel essencial como hospedeiros biológicos para diversas espécies de carrapatos, assim como podem ser úteis como sentinelas de infecções por riquétsias. O intuito deste estudo foi determinar a presença de RTC em cães, assim como em seus carrapatos, para determinar o risco potencial de doença humana em Medellín, Colômbia. DNA de Ehrlichia canis (16S rRNA e dsb) e Anaplasma platys (groEl) foi detectado em 17,6% (53/300) e 2,6% (8/300) dos cães, respectivamente. Anticorpos contra Ehrlichia spp. (82; 27,3%) e Anaplasma spp. (8; 2,6%) foram detectados nos cães. Reatividade de anticorpos contra ambos patógenos (Ehrlichia e Anaplasma) foi detectada em 16 cães (5,3%). Oito animais apresentaram anticorpos contra Rickettsia spp., e 3 deles sugerem uma provável exposição a Rickettsia parkeri. Rhipicephalus sanguineus s.l. (178/193) foi a principal espécie de carrapatos, seguida de R. microplus (15/193). A taxa de infecção mínima em R. sanguineus foi 11,8% para E. canis e 3,4% para A. platys. E. canis e A. platys são as principais RTC que infectam cãese R. sanguineus s.l. provavelmente está envolvido na transmissão de ambos os agentes. É evidente, porém, a exposição sorológica dos cães a riquétsias do grupo da febre maculosa.

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.

The present study aimed to characterize the importance of the Anaplasma marginale, Babesia bovis and Babesia bigemina in the genesis of cattle tick fever (CTF) among dairy calves in the northwest of Minas Gerais, Brazil. Blood samples from 300 calves were collected, followed by DNA extraction and nested PCR using oligonucleotide primers to amplify fragments of the semi-nested for the msp5 gene (A. marginale), sbp-4 (B. bovis) and rap-1a (B. bigemina) Among the examined calves, the prevalence of A. marginale was 55.6% (n=167/300), B. bovis was 4.0% (n=12/300) and B. bigemina was 15.3% (n=46/300), by PCR techniques. Parasitic forms of A. marginale and B. bigemina were found in 36,3% and 2,6% of the blood smears while B. bovis was not detected. There was a statistical difference between the positivity of infected animals in the age groups 1 (10-70 days) and (>70-300 days) for A. marginale and B. bigemina. A total of 15 calves with the classic symptoms of disease were examined, and the samples obtained were confirmed as a simple infection by A. marginale through semi-nested PCR. These results confirm bovine anaplasmosis as the primary cause of CTF among the calves of dairy cattle within the studied area. Resumo O presente estudo teve como objetivo caracterizar a importância de Anaplasma marginale, Babesia bigemina e Babesia bovis na gênese da tristeza parasitária bovina em bezerros leiteiros do noroeste de Minas Gerais. Foram coletadas 300 amostras sanguíneas de bezerros, seguidas por extração de DNA e Nested- PCR utilizando oligonucleotídeos iniciadores que amplificam fragmentos dos genes sbp-4 (B. bovis) e rap-1a (B. bigemina) e a Semi-Nested para o gene msp5 (A. marginale). A prevalência de A. marginale foi 55,66% (167/300), B. bigemina, 15,33% (46/300) e B. bovis 4,0% (12/300) dos bezerros examinados. Formas parasitárias de A. marginale and B. bigemina foram encontradas em 36,33% e 2,66% dos esfregaços sanguíneos, enquanto B. bovis não foi detectado. Houve diferença estatística entre as prevalências de animais infectados nas faixas etárias 1 (10-70 dias) e 2 (>70-300 dias). Um total de 15 animais com sintomas clássicos da doença foram examinados, e as amostras foram confirmadas como uma infecção simples por A. marginale através da Nested-PCR. Esses resultados confirmam a anaplasmose bovina como a principal agente da tristeza parasitária bovina nos bezerros do rebanho estudado.

In the southern cone of South America different haplotypes of Borrelia burgdorferi sensu lato (Bbsl) have been detected in Ixodes spp. from Argentina, southern Brazil, Chile, and Uruguay. So far, Lyme borreliosis has not been diagnosed in Uruguay and the medical relevance of the genus Ixodes in South America is uncertain. However, the growing number of new genospecies of Bbsl in the southern cone region and the scarce information about its pathogenicity, reservoirs and vectors, highlights the importance of further studies about spirochetes present in Uruguay and the region. The aim of this study was to determine the presence of Bbsl in Ixodes auritulus ticks collected from birds and vegetation in two localities of southeastern Uruguay. In total 306 I. auritulus were collected from 392 passerine birds sampled and 1110 ticks were collected by flagging in vegetation. Nymphs and females were analyzed for Borrelia spp. by PCR targeting the flagellin (fla) gene and the rrfA-rrlB intergenic spacer region (IGS). The phylogenetic analysis of Borrelia spp. positive samples from passerine birds and vegetation revealed the presence of four fla haplotypes that form a clade within the Bbsl complex. They were closely related to isolates of Borrelia sp. detected in I. auritulus from Argentina and Canada.

The State of Para has one of the largest herds of equids (horse, donkey and mule) in Brazil, most of these animals are found on cattle farms. Equine theileriosis is a tick-borne disease caused by the parasite Theileria equi and is characterized by fever, anaemia, icterus, intravascular haemolysis, haemoglobinuria, spleen and hepatomegaly, and even death. The present study aimed to determine the prevalence of antibodies against T. equi in equids in the western region of the State of Para, Brazil, and to identify potential risk factors associated with parasite infection. A cross-sectional study was conducted with cluster sampling of farm horses from 18 municipalities. In the cities visited, samples from sport and carthorses were also included. Serum was obtained to detect T. equi-specific antibodies using an indirect enzyme-linked immunosorbent assay (iELISA) based on a crude parasite antigen. In order to identify possible risk factors of the infection which are associated with the prevalence of antibodies, a chi-squared test was carried out. Of 1,117 equids, 373 tested positive for T. equi antibodies with an overall prevalence of 33.4% (31.3%-37.0% for the 95% confidence interval). Sex, animal species and breed were found not to be associated with the presence of T. equi antibodies, whereas age, the presence of dogs or ticks were associated with seropositivity (p < 0.05). Horses with ticks were 2.4 more likely seropositive than horses without ticks. The presence of dogs in the equid habitat and the presence of ticks resulted in a higher T. equi seropositive rate probably because dogs are hosts for vector ticks of T. equi. Our study represents the first report of T. equi antibodies in equids of western Para revealing a widespread distribution of seropositive animals.

There is an increase in tick-borne diseases in dogs in urban and rural areas in Brazil and some of these are of public health importance. Rhipicephalus sanguineus-transmitted hemoparasitoses are the main causes of mortality in dogs. The present study investigated the molecular occurrence of Ehrlichia canis, Babesia vogeli and Anaplasma platys in dogs with clinical sings and hematological abnormalities suggestive of tick-borne diseases. These dogs were seen at a Veterinary Hospital of a Public University between January 2014 and December 2016, and were evaluated through anamnesis, clinical examination and complementary exams. The polymerase chain reaction technique was used to detect the presence of hemoparasites DNA. From the 461 dogs that were tested for B. vogeli, 10.6% (49/461) were positive, the associated variable was age. Regarding the 730 animals screened for E. canis, 15.1% (110/730) were positive, and the infection was associated with hematocrit and number of platelets. Relative to the 86 samples evaluated for A. platys, 15.1% (13/86) were positive, and no variable presented statistical significance. From the animals positive for B. vogeli, no of these showed positivity by qPCR for Rangelia vitalii. It is concluded that the occurrence of hemoparasitosis in dogs from the Londrina region is common. Therefore, it is emphasized that molecular techniques should be used as an auxiliary tool for the differential diagnosis of the different etiological agents causing hemoparasitosis. Additionally, these molecular tools are essential for better investigation and preventive assertiveness because it allows to detect parasite DNA. Há um aumento na ocorrência das doenças transmitidas carrapato em cães em áreas urbanas e rurais no Brasil, algumas, inclusive, são de importância para a saúde pública. As hemoparasitoses transmitidas por Rhipicephalus sanguineus estão entre as principais causas de mortalidade em cães. O presente trabalho teve como objetivo investigar a ocorrência por meio de detecção molecular de Ehrlichia canis, Babesia vogeli e Anaplasma platys em cães com sinais clínicos e anormalidades hematológicas sugestivas de doenças transmitidas por carrapatos. Esses cães foram atendidos em um hospital veterinário de uma universidade pública entre janeiro de 2014 e dezembro de 2016, onde foram avaliados por anamnese, exame clínico e exames complementares. A técnica de reação em cadeia da polimerase foi utilizada para detectar a presença de hemoparasitas. Dos 461 cães testados para B. vogeli, 10,6% (49/461) foram positivos, a variável associada foi a idade. Em relação aos 730 animais testados para E. canis, 15,1% (110/730) foram positivos, e a infecção foi associada ao hematócrito e ao número de plaquetas. Das 86 amostras testadas para A. platys, 15,1% (13/86) foram positivas e nenhuma variável apresentou significância estatística. Dentre os animais positivos para B. vogeli, nenhum foi positivo no qPCR para Rangelia vitalii. Conclui-se que a ocorrência de hemoparasitose em cães da região de Londrina é comum. Assim, enfatiza-se que as técnicas moleculares devem ser utilizadas como ferramentas auxiliares para o diagnóstico diferencial dos diferentes agentes etiológicos causadores da hemoparasitose. Além disso, são essenciais para uma melhor investigação e assertividade preventiva, pois permitem detectar o DNA do parasita.

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.

Amblyomma aureolatum ticks are vectors of Rickettsia rickettsii, the etiologic agent of Rocky Mountain spotted fever in Brazil. Maintenance of R. rickettsii in nature depends on horizontal transmission along tick generations. Although such transmission is known to occur when uninfected and infected ticks feed simultaneously on susceptible animals (co-feeding systemic transmission), we investigated co-feeding nonsystemic transmission, which was based on R. rickettsii-infected and -uninfected A. aureolatum ticks feeding simultaneously on guinea pigs immune to R. rickettsii. Our acquisition and transmission infestations demonstrated that horizontal transmission of R. rickettsii by co-feeding ticks on immune hosts with no systemic infection did not occur when uninfected larvae fed distantly from infected nymphs but did occur in a few cases when uninfected larvae fed side-by-side with infected nymphs, suggesting that they shared the same feeding site. The co-feeding nonsystemic transmission type might have no epidemiologic importance for Rocky Mountain spotted fever.

Borrelia burgdorferi sensu lato (s. l.) spirochetes are associated with a wide range of vectors and hosts. Birds are important hosts in the ecology of some hard ticks (Ixodidae) in northwestern Argentina, where B. burgdorferi s.l. have been detected in Ixodes pararicinus. We evaluated Borrelia infection in ticks collected from wild birds by molecular analysis through the presence of Borrelia DNA (by nested-PCR targeting the fla gene). A total of 381 ticks (357 larvae and 24 nymphs) belonging to four species (I. pararicinus, Haemaphysalis juxtakochi, Haemaphysalis leporispalustris and Amblyomma sp.) were collected. Partial sequences of the fla gene of Borrelia (100% identical to Borrelia sp. haplotype I from Argentina) were detected in 9 of 70 tick pools (6 pools of larvae and 1 pool of nymphs of I. pararicinus, and in 2 pools of H. juxtakochi larvae) collected on Turdus rufiventris, Syndactila rufosuperciliata and Troglodytes aedon. The results of this study suggest that resident birds have reservoir capacity for Borrelia sp. haplotype I. Fil: Flores, Fernando Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Córdoba. Facultad de Medicina. Instituto de Virología "Dr. J. M. Vanella"; Argentina Fil: Muñoz Leal, Sebastián. Universidade de Sao Paulo; Brasil Fil: Diaz, Luis Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina. Universidad Nacional de Córdoba. Facultad de Medicina. Instituto de Virología "Dr. J. M. Vanella"; Argentina Fil: Labruna, Marcelo B.. Universidade de Sao Paulo; Brasil

Chiggers are ectoparasites of vertebrates and may cause trombiculiasis or transmit pathogens to their hosts. Specimens collected from rodents and marsupials were morphologically identified as Herpetacarus hertigi, Eutrombicula tinami, Kymocta sp., Quadraseta brasiliensis, Quadraseta falconensis, Quadraseta flochi, Quadraseta mackenziei, Quadraseta pazca, Quadraseta trapezoides, Quadraseta sp., Serratacarus sp., and Trombewingia bakeri. These mites were submitted individually to molecular analyses for the detection of bacteria of the genus Coxiella, Hepatozoon and Rickettsia. Samples were positive to Rickettsia only. Obtained sequences for the gltA (350 pb) and ompA (488 pb) genes were identical to “Candidatus Rickettsia colombianensi”, a species previously detected in ticks. In addition, molecular identification of mites based on 18S rDNA sequences are provided for H. hertigi, Kymocta sp., Q. brasiliensis, Q. pazca, Q. trapezoides, Quadraseta sp., and T. bakeri for the first time. This is the first report of the detection of a Rickettsia sp. in chigger mites collected on rodents in Brazil. Resumo Os trombiculídeos são ectoparasitas de vertebrados e podem causar trombiculíase ou transmitir patógenos ao hospedeiro. Exemplares coletados em roedores e marsupiais foram identificados morfologicamente como Herpetacarus hertigi, Eutrombicula tinami, Kymocta sp., Quadraseta brasiliensis, Quadraseta falconensis, Quadraseta flochi, Quadraseta mackenziei, Quadraseta pazca, Quadraseta trapezoides, Quadraseta sp., Serratacarus sp. e Trombewingia bakeri. Estes ácaros foram submetidos individualmente à análise molecular para detecção de bactérias dos gêneros Coxiella, Hepatozoon e Rickettsia. Amostras foram positivas somente para Rickettsia. Sequências obtidas para os genes gltA (350 pb) e ompA (488 pb) foram idênticas à “Candidatus Rickettsia colombianensi”, uma espécie anteriormente detectada em carrapatos. Além disso, foram fornecidas sequências de DNA 18S para identificação molecular de H. hertigi, Kymocta sp., Q. brasiliensis, Q. pazca, Q. trapezoides, Quadraseta sp. e T. bakeri. Este é o primeiro registro da detecção de Rickettsia em ácaros trombiculídeos coletados em roedores do Brasil.

The purpose of this study was to do a serological survey on three rickettsial species: Rickettsia rickettsii and Rickettsia parkeri, two species of the spotted fever group (SFG) that are considered to be great importance for public health; and Rickettsia bellii, a species of unknown pathogenicity that infects a variety of human-biting ticks. Serum samples from 273 dogs were tested using the indirect immunofluorescence assay (IFA). A total of 52 samples (19.04%) were seropositive for at least one of the three Rickettsia spp. antigens. Thirty-eight (73.07%), twelve (23.07%) and one (1.92%) of these dogs showed homologous reactions to R. bellii, R. rickettsii and R. parkeri, respectively. Our results showed that the seroprevalence of Rickettsia spp. was relatively low. However, the positive serological tests indicated that these dogs had become infected by these agents at some point in their lives. Lastly, our study adds to the previous knowledge on the epidemiology of rickettsiosis in the state of Goiás by doing the first record of detection of anti-R. rickettsii, R. parkeri and R. bellii antibodies by IFA among dogs, thus indicating that these agents may be circulating in the dog population analyzed. Resumo O objetivo deste estudo foi realizar um levantamento sorológico para três espécies de rickettsias: Rickettsia rickettsii e Rickettsia parkeri, duas espécies do grupo da febre maculosa (GFM) consideradas de grande importância para a saúde pública; e Rickettsia bellii, uma espécie de patogenicidade desconhecida que infecta uma variedade de carrapatos que parasitam seres humanos. Amostras de soro de 273 cães foram testadas, usando-se a técnica de reação de imunofluorescência indireta (RIFI). O total de 52 amostras (19,04%) foram soropositivas para pelo menos um dos três antígenos de Rickettsia spp. Trinta e oito (73,07%), doze (23,07%) e um (1,92%) desses cães apresentaram reações homólogas à R. bellii, R. rickettsii e R. parkeri, respectivamente. Esses resultados demonstraram uma baixa soroprevalência para Rickettsia spp. No entanto, as amostras positivas indicam que esses cães foram infectados por esses agentes em algum momento de suas vidas. Por fim, este estudo contribui para o conhecimento sobre a epidemiologia das rickettsioses no estado de Goiás, realizando a primeira detecção de anticorpos anti-Rickettsia rickettsii, R. parkeri e R. bellii pela RIFI em cães, indicando que esses agentes podem estar circulando na população canina analisada.

Background Rickettsia parkeri strain Atlantic rainforest has emerged in Brazil during the last 10 years, with three laboratory-confirmed human cases. While these cases were epidemiologically associated with the tick Amblyomma ovale, in none of them the tick specimens that bit the patients could be identified. Results We report a clinical case of spotted fever rickettsiosis that was acquired in an Atlantic forest area in Bahia state, northeast Brazil. The case was determined to be caused by R. parkeri strain Atlantic rainforest, based on molecular analysis of the crust removed from the tick bite site (inoculation eschar) of the patients’ skin. DNA extracted from the crust yielded partial sequences of three rickettsial genes (gltA, ompA and ompB), which were 99–100% identical to R. parkeri strain Atlantic rainforest. The tick specimen that was attached to patient skin was identified as a female of A. ovale. Conclusions We report the fourth confirmed case of spotted fever rickettsiosis caused by R. parkeri strain Atlantic rainforest, providing to our knowledge for the first time, direct evidence of R. parkeri strain Atlantic rainforest transmission by A. ovale.

Made available in DSpace on 2019-10-04T12:36:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-04-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG) The giant anteater (Myrmecophaga tridactyla) and the collared anteater (Tamandua tetradactyla) are widespread in Brazil and found in all Brazilian biomes. These hosts frequently use domestic animal environments such as pastures, where tick and related microorganism interchange may occur between hosts. Reports of tick infestations of these animals are scattered and refer to small samples and/or are geographically restricted. We herein present data on a wide geographic distribution of ticks and their Rickettsia collected from 72 giant and 30 collared anteaters, mostly road killed, over a period of 18 years, from Southeast and Central-West Brazil encompassing four States and 46 Municipalities. Overall nine tick species (Amblyomma auricularium, A. calcaratum, A. nodosum, A. ovale, A. parvum, A. sculptum, A. triste, Rhipicephalus microplus and R. sanguineus sensu lato) were collected from anteaters. Amblyomma sculptum, A. nodosum, and A. calcaratum were the most prevalent corresponding to, respectively, 48.8%, 39.3% and 2.7% of all ticks (n = 1775). However, A. nodosum tick numbers on collared anteaters were significantly higher (P < 0.001) than those on giant anteaters. At the same time, an abundance of A. sculptum adults on giant anteaters was significantly higher (Z = 2.875; P = 0.004) than that of A. nodosum and only eight A. sculptum nymphs were found on collared anteaters. DNA samples from 20 ticks from nine different animals yielded a visible amplicon in PCR targeting gltA. The PCR products targeting spotted-fever Rickettsia gene (ompA) from five adults of A. nodosum were sequenced and were shown to be 100% identical to Rickettsia parkeri strain NOD (MF737635.1). The product of one nymph and one adult of A. sculptum yielded a sequence 99% identical to R. parkeri strain NOD. Further, Rickettsia bellii genes were found in three A. nodosum adults. Ecological, behavioral and anatomical traits of anteaters are discussed to explain reported tick infestations and Rickettsia DNA found. Univ Fed Uberlandia, Fac Med Vet, Lab Ixodol, Av Para 1720,Campus Umuarama Bloco 2T, BR-38400902 Uberlandia, MG, Brazil Inst Fed Goiano, Campus Urutai,Rod Geraldo S Nascimento Km 2,5, BR-75790000 Urutai, Go, Brazil Univ Fed Uberlandia, Inst Ciencias Biomed, Lab Virol, Av Para 1720,Campus Umuarama Bloco 2B, BR-38400902 Uberlandia, MG, Brazil Univ Brasilia, Lab Patol Vet, Av L4 Norte,Hosp Vet Campus Univ Darcy Ribeiro, BR-70910970 Brasilia, DF, Brazil Univ Sao Paulo, Fac Med Vet & Zootecn, Dept Med Vet Prevent & Saude Anim, Av Prof Orlando Marques de Paiva 87,Cidade Univ, BR-05508270 Sao Paulo, SP, Brazil Univ Estadual Paulista, Dept Patol, Via Acesso Prof Paulo Donato Castellane S-N, BR-14884900 Jaboticabal, SP, Brazil Inst Estadual Florestas, Praca Tubal Vilela 03, BR-38400186 Uberlandia, MG, Brazil Univ Estadual Paulista, Dept Patol, Via Acesso Prof Paulo Donato Castellane S-N, BR-14884900 Jaboticabal, SP, Brazil

In humans, emerging infectious diseases are mostly zoonoses with ticks playing an important role as vectors. Tick-borne relapsing fever Borrelia and spotted fever Rickettsia occur in endemic foci along tropical and subtropical regions of the globe. However, both are widely neglected etiologic agents. In this study, we performed molecular analyses in order to assess the presence of Borrelia and Rickettsia DNA in ticks infesting small-mammals within a National Reserve located in the Andes Mountains, central Chile. While hard ticks were negative for the presence of both agents, sequences of four rickettsial (gltA, htrA, ompA, ompB) and two borrelial (16S rRNA and flaB) genes were obtained from larvae of an Ornithodoros sp. morphologically related with Ornithodoros atacamensis. Phylogenetic analyses indicated that the detected Borrelia and Rickettsia spp. belong to the relapsing fever and spotted fever groups, respectively. Moreover, the agents formed monophyletic clades with Rickettsia amblyommatis and “Candidatus Borrelia johnsonii.” As positive ticks parasitize rodents within a highly visited National Reserve where outdoor activities are of common practice, the risk for human parasitism should not be discarded.

Canine rangeliosis is an extravascular hemolytic disease caused by the protozoan Rangelia vitalii, which is transmitted by ticks of the species Amblyomma aureolatum. Te most common clinical signs are apathy, hyperthermia and spontaneous bleeding. Anemia and thrombocytopenia are the most common hematological fndings. Tis work reports a clinical case of canine Rangeliosis treated at a private veterinary hospital, in São Paulo city in 2017. A dog was treated at a veterinary hospital in the north of São Paulo, with progressive weight loss, apathy and tail injury. Anemia and thrombocytopenia were observed on the hemogram. Rangelia vitalii DNA was detected in animal blood by real-time PCR (qPCR). In addition to the supportive treatment, doxycycline and subcutaneous imidocarb applications were used. Te sample collected afer treatment with the antibiotic continued to present protozoal DNA. Te disease should be considered as a diferential diagnosis and there is a great need for further studies about the therapy used.

Introdução: A febre maculosa (FM) é uma doença transmitida por carrapatos, o que, no Brasil, preocupa as autoridades do Sistema Único de Saúde (SUS) por apresentar elevados coeficientes de letalidade. Objetivo: Descrever os conhecimentos e as atitudes de prevenção sobre a FM entre profissionais do SUS. Métodos: Foi realizado entre os meses de outubro a dezembro de 2015, um inquérito sobre os conhecimentos e as atitudes de prevenção sobre a FM entre os profissionais da saúde. Um questionário na plataforma FormSUS foi submetido a 426 profissionais de todo o Brasil que previamente já haviam participado de capacitações e atividades que envolviam o tema em questão. Vinte unidades federadas foram respondedoras da pesquisa (112/426). Foi possível verificar que a maioria dos profissionais de saúde conhece as condutas de notificação e de investigação epidemiológica. As incorporações recentes no programa de vigilância epidemiológica são de conhecimento da maioria dos respondentes. A rotatividade dos profissionais foi mencionada como principal dificultador das ações de vigilância da doença. Ações de fortalecimento dos programas de vigilância são realizadas de forma esporádica, somente no momento da ocorrência de casos de FM e não ocorrem de forma integral no âmbito do SUS. Conclusão: Cabe a cada segmento do SUS buscar seguir as diretrizes do sistema de vigilância epidemiológica da FM para que, de forma integral, se consiga reverter o panorama de morbimortalidade desta importante doença no Brasil.

Among the 69 tick species currently recognized in Brazil, only 13 have been reported in the state of Espírito Santo, southeastern Brazil. This study reports new tick records from Espírito Santo, and investigated the infection by rickettsial bacteria in these ticks. During 2012-2016, ticks were occasionally collected from different sources in Espírito Santo. In addition, we revised tick unpublished records from Espírito Santo in a tick collection. A total of 1263 tick specimens comprising 19 tick species (17 Ixodidae, 2 Argasidae) were collected. The following seven tick species are reported for the first time in Espírito Santo: Amblyomma aureolatum, Amblyomma coelebs, Amblyomma ovale, Amblyomma rotundatum, Amblyomma varium, Haemaphysalis juxtakochi, and Ornithodoros hasei. The only tick species previously reported for Espírito Santo, but not found in the present study, is A. longirostre. A total of 194 ticks of 7 species were tested for rickettsial infection. Three Rickettsia species were detected: Rickettsia bellii in A. aureolatum, Rickettsia rhipicephali in H. juxtakochi, and Rickettsia amblyommii in A. humerale. The present study increases the tick fauna of Espírito Santo to 20 species (29% of the Brazilian tick fauna). Additionally, 3 Rickettsia species are reported for the first time in this region of Brazil.

Arthropod-borne pathogens are medically important because of their ability to cause diseases in their hosts. The purpose of this study was to detect the occurrence of Ehrlichia spp., piroplasmids and Hepatozoon spp. in dogs with anemia and thrombocytopenia in southern Brazil. EDTA-whole blood was collected from 75 domestic dogs presenting anemia or/and thrombocytopenia from Guarapuava, state of Paraná, Brazil. DNA samples were subjected to conventional PCR assays for Ehrlichia spp. (dsb), piroplasmids (18S rRNA) and Hepatozoon spp. (18S rRNA), followed by sequencing and phylogenetic analyses. Among the 75 dogs, one (1.33%) was positive for Hepatozoon sp. and six (8%) were positive for piroplasmids in 18S rRNA cPCR assays. None of the dogs showed positive results in Ehrlichia spp.-cPCR targeting dsb gene. The phylogenetic analyses revealed that three piroplasm sequences were clustered with Rangellia vitalii, while one sequence was grouped with B. vogeli. The only sequence obtained from Hepatozoon spp.-PCR protocol was pooled with H. canis. Therefore, there is urgent need for differential molecular diagnosis of the two piroplasm species cited as etiological agents in clinical cases of canine hemoparasitic diseases, given the higher pathogenic potential of R. vitalii than of B. vogeli. Resumo Agentes transmitidos por artrópodes têm grande importância na medicina veterinária devido à sua capacidade de causar doenças graves em seus hospedeiros. O presente estudo objetivou investigar a ocorrência de três patógenos transmitidos por vetores, Ehrlichia canis, Rangelia vitalii e Hepatozoon canis, em cães na região sul do Brasil. Foram coletadas amostras de sangue total de 75 cães domésticos que apresentavam anemia e/ou trombocitopenia, em Guarapuava, Paraná, Brasil. As amostras de DNA foram submetidas à técnica de PCR convencional para E. canis (dsb), piroplasmídeos (18S rRNA) e Hepatozoon spp. (18S rRNA), seguida de sequenciamento e análises filogenéticas. Das 75 amostras, uma (1,33%) foi positiva para Hepatozoon spp. e seis (8%) foram positivas para Babesia spp. Nenhuma amostra mostrou resultados positivos para Ehrlichia spp. utilizando a detecção pelo gene dsb. As análises filogenéticas revelaram que três sequências obtidas foram agrupadas no mesmo clado que R. vitalii , enquanto uma foi agrupada juntamente com B. vogeli. A única sequência obtida pelo protocolo de PCR para Hepatozoon spp. foi agrupada juntamente com H. canis. Assim, é justificada necessidade de diferenciação das espécies de piroplasmas, através do diagnóstico molecular, como agentes etiológicos nos casos clínicos de hemoparasitose canina, considerando o potencial patogênico de R. vitalii quando comparado à B. vogeli.

Made available in DSpace on 2018-11-26T17:55:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-09-17 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) There are two distinct lineages of ticks, Rhipicephalus sanguineus, in South America: tropical and temperate lineages. Only the tropical lineage is recognized as competent vector for Ehrlichia canis. The epidemiological data of canine monocytic ehrlichiosis is congruent with the distribution of the two lineages of R. sanguineus. Herein, we report the infection of R. sanguineus (tropical lineage) cell cultures with E. canis, after cryopreservation. R. sanguineus (tropical lineage) cell identity was confirmed by sequencing using a 16S rDNA gene fragment. Tick cell cultures were prepared in L-15B medium supplemented with 10%, 15%, and 20% Fetal Bovine Serum (FBS), and 10% of Tryptose Phosphate Broth (TPB). Cell cultures developed better at the concentration of 20% of FBS. Cultures in the fifth harvest (approximately 7 months later) were selected for the first infections. Optimal R. sanguineus cell growth and adhesion was observed (5.0x10(6) cells/mL, and the population doubling time every 57h). Once infected with E. canis, the cultures were maintained in L-15B medium supplemented with 2% and 5% of FBS fortified with iron and 10% TPB. Infected cells were also cryopreserved. DNA was extracted from infected and noninfected cells and analyzed using quantitative real-time PCR targeting the E. canis-dsb gene. Primary culture of the fifth passage was infected by E. canis and it maintained the pathogen for at least 40 days before partial cell destruction. Subcultures of infected cells (fresh and cryopreserved cultures) onto new tick cell cultures were successful. The E. canis infection was confirmed by real-time PCR and light and transmission electron microscopy. The R. sanguineus (tropical lineage) cells infected with E. canis successfully infected new tick cell cultures, showing that these cells could be an alternative substrate for maintenance of this pathogen. State Univ Julio de Mesquita Filho UNESP, Fac Agr & Vet Sci, Dept Vet Pathol, BR-14884900 Jaboticabal, Brazil Butantan Inst, Lab Parasitol, Sao Paulo, Brazil Fed Univ Latin Amer Integrat UNILA, Foz Do Iguacu, Brazil Univ Sao Paulo, Sch Vet Med, Dept Prevent Vet Med & Anim Sci, Sao Paulo, Brazil Univ Santo Amaro, Vet Med, Sao Paulo, Brazil Univ Fed Uberlandia, Uberlandia, MG, Brazil State Univ Julio de Mesquita Filho UNESP, Fac Agr & Vet Sci, Dept Vet Pathol, BR-14884900 Jaboticabal, Brazil FAPESP: 2007/57749-2 FAPESP: 2015/26209-9 CNPq: 312331/2013-4

Microorganisms harbored by Chilean autochthonous ticks have been scarcely studied and current knowledge is restricted to three species of hard ticks only. The current study aimed to assess the presence of Anaplasmataceae, Borrelia and Hepatozoon agents in ticks collected directly from the environment, on reptiles, birds and mammals in twelve localities from northern, central and southern regions of the country and Antarctica. Ticks were identified by means of a morphological and molecular approach. PCR detections point the occurrence of an Anaplasma-like agent and a relapsing fever Borrelia sp. in Ornithodoros spheniscus; an Ehrlichia sp. and a Hepatozoon sp. in Ornithodoros atacamensis; “Candidatus Neoehrlichia chilensis”, Borrelia burgdorferi sensu lato (s. l.), and Hepatozoon in Ixodes ticks morphologically related to the Ixodes sigelos group; and B. burgdorferi s. l. in Ixodes auritulus. Supported by phylogenetic analyses of characterized microorganisms, this study introduces putative vector roles and initial evidence on possible new agents detected in Chilean ticks.

teste

The bacterium Rickettsia bellii belongs to a basal group of rickettsiae that diverged prior to the pathogenic spotted fever group and typhus group Rickettsia species. Despite a diverse representation of R. bellii across more than 25 species of hard and soft ticks in the American continent, phylogeographical relationships among strains of this basal group-Rickettsia species are unknown; the work described here explores these relationships. DNA was extracted from 30 R. bellii tick isolates: 15 from the United States, 14 from Brazil, and 1 from Argentina. A total of 2,269 aligned nucleotide sites of 3 protein coding genes (gltA, atpA, and coxA) and 2 intergenic regions (rpmE-tRNAfmet and RC1027-xthA2) were concatenated and subjected to phylogenetic analysis by Bayesian methods. Results showed a separation of almost all isolates between North and South Americas, suggesting that they have radiated within their respective continents. Phylogenetic positions of the 30 isolates could be a result of not only their geographical origin but also the tick hosts they have coevolved with. Whether R. bellii originated with ticks in North or South America remains obscure, as our analyses did not show evidence for greater genetic divergence of R. bellii in either continent.

Rickettsia parkeri strain Atlantic rainforest (SAR) is the etiological agent of a spotted fever group rickettsiosis in Brazil, where it is transmitted to humans by the tick Amblyomma ovale. A previous study demonstrated that R. parkeri SAR was successfully maintained in A. ovale ticks by transstadial and transovarial passages; however, because this agent induced lower reproduction rates in A. ovale, the participation of a vertebrate amplifier host, yet to be determined, was speculated. Since the rice rat Euryoryzomys russatus was demonstrated to be the most important host for immature stages of A. ovale in a focus of R. parkeri SAR transmission, the present study evaluated the competence of rice rats to act as amplifying host of R. parkeri SAR for A. ovale ticks. Rice rats were infested with R. parkeri SAR-infected A. ovale nymphs, and four days later with uninfected A. ovale larvae. Rickettsial transmission to rats was confirmed by seroconversion to R. parkeri antigens. Detached engorged larvae were allowed to molt to nymphs, in which rickettsial DNA was detected in up to 60% (mean: 20%) of the specimens. When part of these nymphs was allowed to feed on susceptible rice rats, rickettsial transmission was confirmed by seroconversion, indicating that there was successful horizontal transmission of R. parkeri SAR from infected nymphs to uninfected larvae in the previous acquisition infestations. Because we used naive, susceptible rats, we infer that this horizontal transmission occurred via a systemic infection (rickettsemia) in the rat. Our results, coupled with previous epidemiological studies, suggest that under natural conditions rice rats could be acting as amplifying hosts of R. parkeri SAR to A. ovale ticks.

This study aimed to determine the dynamics of natural infection in the transmission of Babesia spp. to cattle in an enzootic instability area in Northeastern Brazil. Blood samples were collected from 30 calves located on two dairy farms to determine the packed cell volume (PCV) and the timing of the primo-infection using polymerase chain reaction (PCR) and their association with climatic factors and management practices. On Farm A, the determination of primo-infection was observed on average at 249.4 (±24.42) days of age for B. bigemina and at 252.6 (±17.07) days of age for B. bovis; there was no significant difference between the times of infection (P> 0.05). The infection coincided with a period of high rainfall in the region. On Farm B, primo-infection infection was not observed. There was no infection by Babesia spp. on Farm B due to the intensive use of acaricides that led to an absence of ticks. There was no significant difference between the average PCV of animals from Farms A and B (P> 0.05). The management practices on the properties, in addition to the weather conditions influenced the exposure of the animals to disease vectors and may have contributed to the maintenance of this enzootic area in Northeastern Brazil. Resumo Este estudo teve como objetivo determinar a dinâmica da infecção natural na transmissão de Babesia spp. em bovinos de uma área de instabilidade enzoótica no Nordeste do Brasil. Foram coletadas amostras de sangue de 30 bezerras, proveniente de duas propriedades leiteiras para determinação do volume globular e da primo-infecção por meio da reação em cadeia da polimerase associando aos fatores climáticos e medidas de manejo. Na fazenda A, o período médio da primo-infecção para B. bigemina, determinado por meio da PCR, foi de 249,4 (±24,42) dias de idade, enquanto que para B. bovis foi aos 252,6 (±17,07) dias de idade, não existindo diferença estatística. A infecção coincidiu com o período de alta precipitação pluviométrica na região. Não houve infecção por Babesia spp. na fazenda B, na qual o uso intensivo de acaricidas determinou ausência de carrapatos. Não houve diferença significativa entre médias de VG dos animais das fazendas A e B. O manejo adotado nas fazendas estudadas, associado às condições climáticas, interferem na exposição dos animais aos vetores, podendo favorecer a manutenção de uma área de instabilidade enzoótica no Nordeste do Brasil.

Made available in DSpace on 2018-12-11T17:34:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-01-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) 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. Universidade Estadual Paulista (Unesp) Faculdade de Ciências Agrárias e Veterinárias, Jaboticabal Universidade Católica Dom Bosco Universidade Federal da Paraíba Laboratório de Ecologia Animal, Rio Tinto Universidade de São Paulo Faculdade de Medicina Veterinária e Zootecnia Universidade Estadual Paulista (Unesp) Faculdade de Ciências Agrárias e Veterinárias, Jaboticabal

Spotted fevers are tick-borne diseases associated with various Rickettsia species. Rickettsia parkeri sensu stricto (s.s.) is the agent of an emerging eschar-associated rickettsiosis in humans from the USA and South American Pampa. Considering that R. parkeri s.s. is restricted to Americas and the potential role of dogs in the epidemiology of the disease, it is thus reasonable to hypothesize that wild canids could be involved in the enzootic cycle of this rickettsiosis. The aim of this work was to investigate the potential role of the wild canids from Pampa, Cerdocyon thous (crab-eating fox) and Lycalopex gymnocercus (Pampas fox), in the ecology of R. parkeri s.s. For that, 32 live-trapped free-ranging wild canids were sampled. Ticks were observed in 30 of the 32 foxes. Of the 292 ticks collected, 22 (7.5%) were positive by PCR for the presence of R. parkeri s.s. DNA. Also, 20 (62%) wild canids showed antibodies against R. parkeri. The results suggest that wild canids are involved in the enzootic cycle of R. parkeri s.s. in the Pampa biome and could be responsible for pathogen (and its vectors) dispersal.

More than seventy tick species have been reported in Brazil. Despite the emergence of tick-borne diseases in Neotropical region, there are still limited data available on tick species parasitizing humans in Brazil. Rio Grande do Sul is the southernmost state of Brazil, comprising the only part of Brazilian territory inside the Pampa biome, as well as the transition between subtropical and temperate zones. Here, we report on human parasitism by ticks in Rio Grande do Sul state between 2004 and 2017. Seventy cases of human parasitism by ticks were recorded, with a total of 81 tick specimens collected. These included 11 tick species belonging to three genera of Ixodidae (hard-ticks), Amblyomma, Haemaphysalis and Rhipicephalus; and one genus of Argasidae, Ornithodoros. The most prevalent tick species associated to cases of human parasitism were Amblyomma parkeri (24%), Rhipicephalus sanguineus sensu lato (22%), Amblyomma aureolatum (15%) and Amblyomma ovale (12%). A spatial analysis showed two major hot spots of human parasitism by ticks in Rio Grande do Sul state. The findings of this study highlight the need for permanent monitoring of human parasitism by ticks in order to provide a better understanding of tick and tick-borne disease eco-epidemiology, and the early identification of potential cases of tick-borne diseases, particularly in spotted fever endemic regions.

The aim of this study was to analyze the prevalence of rickettsiae in the tree-hole tick Ixodes arboricola in the Czech Republic and Slovakia. During May to September of 2009 and 2013, bird boxes belonging to three different areas were screened for ticks. In total, 454 nestlings and 109 nests of 10 hole-breeding bird species were examined. Ticks were found on Ficedula albicollis, Parus major, Cyanistes caeruleus and Sitta europaea and/or in their nests. In total, 166 ticks (17 nymphs, 10 males and 139 females) were found at 3 areas (arithmetic mean ± standard error: 55.3 ± 45.9). All ticks were tested for the presence of Rickettsia species by polymerase chain reaction targeting the rickettsial genes gltA, ompA, ompB and htrA and amplicon sequencing. All individuals except 3 nymphs were infected with ‘Candidatus Rickettsia vini’. Multilocus sequence typing showed closest proximity to Rickettsia japonica and Rickettsia heilongjiangensis cluster. The presence of ‘Ca. R. vini’ is reported for the first time in Slovakia.

Although Espirito Santo state is considered an endemic area for Brazilian spotted fever (BSF) with related lethal cases, it also constitutes the only state of southeastern Brazil that currently lacks a specific confirmation of the specific rickettsial agent. In an attempt to a species level confirmation of the etiological agent of fatal rickettsiosis cases in Espirito Santo state, in this study we tested human sera obtained between 2015 to 2017 by means of qPCR and subsequent conventional PCR protocols targeting gltA (citrate synthase) and ompA (190-kDA outer membrane protein) rickettsial genes. All samples were found to contain rickettsial DNA through the citrate synthase qPCR protocol. By conventional PCR, rickettsial gltA and ompA specific DNA fragments were detected in 25% (one sample) and 50% (2 samples) of the screened sera, respectively. Obtained consensuses for each gene partial sequences were 100% identical to Rickettsia rickettsii gltA and ompA genes. The present study confirms for the first time R. rickettsii as the etiological agent of a lethal spotted fever group rickettsiosis in human patients from Espirito Santo state.

This study investigated the occurrence of rickettsial infection in ticks collected from wild animals in two areas of Brazil. Amblyomma dubitatum ticks were collected from a capybara (Hydrochoerus hydrochaeris) in Guarda-Mor municipality, state of Minas Gerais, and Amblyomma pseudoconcolor ticks were collected from a six-banded armadillo (Euphractus sexcinctus) in Corumbá municipality, state of Mato Grosso do Sul. Attempts to isolate rickettsia in Vero cell culture were performed with one A. dubitatum tick and one A. pseudoconcolor tick, which were previously shown by the hemolymph test to contain Rickettsia-like structures within their hemocytes. Rickettsiae were successfully isolated in Vero cell culture from the two tick species. The two isolates were identified as Rickettsia bellii, since gltA partial sequences were 99.9%-100% identical to corresponding sequences of R. bellii in GenBank. While there have been several previous reports of R. bellii infecting A. dubitatum ticks, we provide the first report for A. pseudoconcolor, which increases to 25 the number of R. bellii-infected tick species in the American continent. O presente trabalho investigou a ocorrência de infecção por Rickettsia em carrapatos coletados em animais selvagens de duas áreas do Brasil. Carrapatos da espécie Amblyomma dubitatum foram coletados de uma capivara (Hydrochoerus hydrochaeris) no município de Guarda-Mor, Minas Gerais, enquanto exemplares da espécie Amblyomma pseudoconcolor foram coletados de um tatu-peba (Euphractus sexcinctus) do município de Corumbá, Mato Grosso do Sul. Tentativas para isolar Rickettsia em cultura de células Vero foram realizadas com um exemplar de A. dubitatum e um de A. pseudoconcolor, que foram previamente positivos no teste de hemolinfa com estruturas semelhantes a Rickettsia visualizadas em seus hemócitos. Rickettsia foram isoladas com sucesso em culturas de células Vero a partir das duas espécies de carrapatos. Os dois isolados foram identificados como Rickettsia bellii, uma vez que suas sequências parciais do gene gltA foram 99,9-100%, idênticas a sequências de R. bellii do GenBank. Embora haja vários relatos anteriores de R. bellii infectando A. dubitatum, este é o primeiro relato em A. pseudoconcolor, aumentando para 25 o número de espécies de carrapatos infectadas por R. bellii no continente americano.