Human Parasitism by Amblyomma parkeri Ticks Infected with Candidatus Rickettsia paranaensis, Brazil.

Spotted fever is the main rickettsial disease in Brazil. We report 12 cases of human parasitism by Amblyomma parkeri in the Atlantic rainforest, an area of Brazil to which spotted fever is endemic. Nine of the ticks were infected with Candidatus Rickettsia paranaensis.

Relative transcription of autophagy-related genes in Amblyomma sculptum and Rhipicephalus microplus ticks.

Ticks endure stressful off-host periods and perform as vectors of a diversity of infectious agents, thus engaging pathways that expectedly demand for autophagy. Little is known of ticks' autophagy, a conserved eukaryotic machinery assisting in homeostasis processes that also participates in tissue-dependent metabolic functions. Here, the autophagy-related ATG4 (autophagin-1), ATG6 (beclin-1) and ATG8 (LC3) mRNAs from the human diseases vector Amblyomma sculptum and the cattle-tick Rhipicephalus microplus were identified. Comparative qPCR quantifications evidenced different transcriptional status for the ATG genes in the salivary glands (SG), ovaries and intestines of actively feeding ticks. These ATGs had increased relative transcription under nutrient-deprivation, as determined by validation tests with R. microplus embryo-derivative cells BME26 and A. sculptum SG explants incubations in HBSS. Starvation lead to 4-31.8× and ~ 60-500× increments on the ATGs mRNA loads in BME26 and A. sculptum SG explants, respectively. PI3K inhibitor 3MA treatment also affected ATGs expression in BME26. Some ATGs were more transcribed in the SGs than in the ovaries of cattle-ticks. Amblyomma sculptum/R. microplus interspecific comparisons showed that ATG4 and ATG6 were 0.18× less expressed in A. sculptum SGs, but ~ 10-100× more expressed in their ovaries when compared to R. microplus organs. ATG4 and ATG8a transcript loads were ~ 120× and ~ 40× higher, respectively, in A. sculptum intestines when compared to cattle-ticks of similar weight category. ATGs expression in A. sculptum intestines increased with tick weight, indicating Atgs contribution to intracellular blood digestion. Possible roles of the autophagy machinery and their organ-specific expression profile on vector biology are discussed.

Coxiella symbionts are widespread into hard ticks.

Ticks are blood-feeding arthropods and can harbor several bacteria, including the worldwide zoonotic disease Q-fever agent Coxiella burnetii. Recent studies have reported a distinct group of Coxiella mostly associated with Ixodidae ticks, including the primary endosymbionts of Amblyomma americanum. In the present work, a screening for Coxiella infection was performed by 16S ribosomal DNA (rDNA) gene analyses in 293 tick samples of 15 different species sampled worldwide, including Brazil, Colombia, Kenya, and China. Different Coxiella phylotypes were identified, and these putative symbiotic bacteria were detected in ten different Amblyomma tick species. Approximately 61 % of Rhipicephalus sanguineus and ∼37 % of Rhipicephalus microplus DNA samples were positive for Coxiella. Sequence analysis and phylogenetic reconstruction grouped all the detected Coxiella with Coxiella-like symbionts from different Ixodidae ticks. This well-defined clade clearly excludes known phylotypes of C. burnetii pathogens and other Coxiella spp. detected in different environmental samples and other invertebrate hosts.

Effect of environmental variables on the abundance of Amblyomma ticks, potential vectors of Rickettsia parkeri in central Brazil.

Amblyomma ticks are vectors of both Rickettsia rickettsii and R. parkeri in the Americas, where capybaras (Hydrochoerus hydrochaeris) are the main hosts in urban areas, thus contributing to the transmission of spotted fever. Herein, we studied: (i) the seasonal dynamics and abundance of ticks in areas where capybaras live, (ii) the effect of environmental variables on tick abundance, and (iii) the presence of Rickettsia-infected ticks. Between September 2021 and September 2022, we sampled ticks using cloth-dragging at 194 sites on the shore of Lake Paranoá in Brasília, Brazil. We measured environmental data (season, vegetation type, canopy density, temperature, humidity, and presence or vestige of capybara) at each site. Nymphs and adults were morphologically identified to the species level, and a selected tick sample including larvae was subjected to genotypic identification. We investigated Rickettsia-infected ticks by PCR (gltA, htrA, ompB, and ompA genes) and associations between tick abundance and environmental variables using Generalized Linear Models. A total of 30,334 ticks (96% larvae) were captured. Ticks were identified as Amblyomma, with A. sculptum comprising 97% of the adult/nymphs. Genotype identification of a larval sample confirmed that 95% belonged to A. dubitatum. Seasonal variables showed significant effects on tick abundance. Most larvae and nymphs were captured during the early dry season, while the adults were more abundant during the wet season. Vegetation variables and the presence of capybaras showed no association with tick abundance. Rickettsia parkeri group and R. bellii were identified in A. dubitatum, while A. sculptum presented R. bellii. We conclude that: (i) Amblyomma ticks are widely distributed in Lake Paranoá throughout the year, especially larvae at the dry season, (ii) the abundance of Amblyomma ticks is explained more by climatic factors than by vegetation or presence of capybaras, and (iii) A. dubitatum ticks are potential vectors of R. parkeri in Brasília.

Hepatozoon Infecting Bats in the Southeastern Brazilian Rainforest.

Tick-borne protozoans of the genus Hepatozoon are obligate hemoparasites that can infect domestic and wild terrestrial vertebrates. Main hepatozoonosis affects canids and involves mainly Hepatozoon canis and Hepatozoon americanum. However, molecular studies revealed the capacity of H. canis to infect a wide range of wild mammals. In July 2018, we conducted an epidemiological survey for tick-borne pathogens in wild hosts, assaying Hepatozoon sp. occurrence in 34 bats captured in different habitats within a conservation unit in the state of Espírito Santo, southeastern Brazil. Blood and spleen tissue DNA samples were submitted to PCR amplifications of Babesia/Theileria and Hepatozoon 18S rRNA gene and 21% (7/34) were positive for Hepatozoon sp. Phylogenetic inferences grouped the obtained sequences from Seba's short-tailed bat (Carollia perspicillata) with the H. canis cluster, and from the great fruit-eating bat (Artibeus lituratus) with rodent-associated Hepatozoon cluster. Further studies are needed to characterize the epidemiological role of Seba's short-tailed bat and the great fruit-eating bat in the wild transmission cycle of these hemoparasites in Brazil.

Two new species of the genus Geckobia Mégnin, 1878 (Acariformes, Prostigmata, Pterygosomatidae) from Peru.

Two new species of Geckobia Mégnin, 1878, Geckobia andina n. sp. and Geckobia circumdata n. sp., ectoparasites commonly reported on geckos, are described from the host species Phyllodactylus gerrhopygus (Wiegmann). The specimens were collected in the subtropical region of the Andean Pacific of Peru. The geographic distribution of species of Geckobia in South America and the Caribbean are mapped. Furthermore, a dichotomous key for the species of New World Geckobia is provided.

Rickettsia sp. Strain NOD Infecting Ticks ( Amblyomma nodosum) in an Endemic Area of Spotted Fever in Brazil.

Amblyomma nodosum ticks were collected from one collared anteater ( Tamandua tetradactyla) in the Caatinga biome, Brazil. From one sample, we isolated a Rickettsia sp. that was phylogenetically close to Rickettsia sp. strain NOD, with 99.9, 100.0, and 99.8% identity for gltA, htrA, and ompA genes, respectively.

Spotted Fever: Epidemiology and Vector-Rickettsia-Host Relationship in Rio de Janeiro State.

The eco-epidemiological scenario of spotted fever (SF), a tick-borne disease that affects humans and other animals in several countries around the world, was analyzed in Rio de Janeiro (RJ) State, Brazil. During the last 34 years, 990 SF cases were reported in RJ (the Brazilian state with the highest population density), including 116 cases confirmed by serology (RIFI) or PCR, among 42.39% of the municipalities with reported cases of SF. The epidemiologic dynamics of SF in RJ State are very heterogeneous in time and space, with outbreaks, high mortality rates and periods of epidemiological silence (no SF cases reported). Furthermore, it exhibited a changing epidemiological profile from being rural to becoming an urban disease. This study identified arthropods infected with Rickettsia felis, R. bellii and R. rickettsii, and found that the abundance of ectoparasites was associated with specific hosts. The R. rickettsii-vector-host relationship was most evident in species-specific parasitism. This suggests that the association between dogs, cattle, horses, capybaras and their main ectoparasites, Rhipicephalus sanguineus and Ctenocephalides felis, Rhipicephalus microplus, Dermacentor nitens, and Amblyomma dubitatum, respectively, has a key role in the dynamics of R. rickettsii transmission in enzootic cycles and the maintenance of carrier ectoparasites, thus facilitating the existence of endemic areas with the ability to produce epidemic outbreaks of SF in RJ. This study found confirmed human infections for only the R. rickettsii carrier Amblyomma sculptum, which reinforces the importance of this species as a vector of the pathogen in Brazil. This study can be adapted to different eco-epidemiological scenarios of spotted fever throughout the Americas.

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

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

Anaplasmataceae em gatos (Felis catus) no município de Campos dos Goytacazes, Rio de Janeiro / Anaplasmataceae in cats (Felis catus) in the city of Campos dos Goytacazes, Rio de Janeiro

No Brasil, até o ano 2000, os agentes riquetsiais em felinos domésticos eram poucos conhecidos, existindo somente relatos esporádicos de Ehrlichia sp. As recentes pesquisas envolvendo biologia molecular e agentes riquetsiais confirmam a ideia de que estes agentes estão presentes nesses animais e, por este motivo, demonstram a necessidade de estudos mais detalhados no Brasil. O objetivo do presente trabalho foi a caracterização dos agentes da família Anaplasmataceae que acometem os felinos domésticos e esclarecer a importância dos felinos na cadeia epidemiológica das doenças riquetsiais por métodos moleculares e sorológicos associando a presença das doenças aos parâmetros clínicos e laboratoriais. Foram obtidas amostras sanguíneas de 60 felinos domésticos, independentes de sanidade, provenientes de atendimentos clínicos. Destas amostras foram realizados hemograma e bioquímica sérica, e os dados foram utilizados para preenchimento da ficha laboratorial. As amostras foram processadas para obtenção de concentração de células e soro, para realização da reação em cadeia pela polimerase (PCR) e reação por imunofluorescência indireta (RIFI), respectivamente, para identificação de agentes da família Anaplasmataceae. Os dados foram utilizados para análise descritiva para formação de frequências epidemiológicas e para realização de testes não-paramétricos pelo Qui-quadrado de Pearson (p≤5%) associando as alterações laboratoriais às infecções por Ehrlichia canis, Anaplasma platys e Anaplasma phagocytophilum. Os resultados obtidos revelaram a presença de 33,33% de agentes Anaplamastaceae na amostra populacional, sendo 8,33% para E. canis, 20% para A. platys e 10% para A. phagocytophilum. Foram realizadas as sorologias das amostras, pela imunofluorescência indireta, para verificação de amostras reagentes para A. phagocytophilum, sendo 8,33% amostras reagentes na amostra populacional. As alterações clínicas e laboratoriais mais frequentes em pacientes positivos por agentes Anaplasmataceae foram letargia, linfadenomegalia, mucosas pálidas, desidratação, trombocitopenia, hiperglobulinemia e hipoalbuminemia. Destes dados foram realizadas as correlações não paramétricas e não foram verificadas dependências das alterações laboratoriais com a presença de animais positivos para agentes Anaplasmataceae. A identificação dos agentes E. canis e A. platys visa esclarecer a doença na região, sendo instrumento de orientação da doença pelo médico veterinário ao proprietário para que tenha medidas adequadas de tratamento e prevenção. A presença de agentes A. phagocytophilum é considerada, sem dúvidas, uma notificação importante devido ao potencial zoonótico.(AU)

In Brazil, by the year 2000, rickettsioses in domestic cats were little known and there were only sporadic reports of Ehrlichia sp. Recent research involving molecular biology and rickettsioses confirm the notion of the presence of theses agents in cats and show the need for more studies in Brazil. The objective of this paper was to characterize agents belonging to the Anaplasmataceae family that affect domestic cats and to clarify the importance of cats in the epidemiology of rickettsioses by molecular and serological methods associating the presence of disease with clinical and laboratory parameters. Blood samples were obtained from 60 healthy domestic cats. Blood count and serum biochemical tests were performed, and the data were registered. The samples were processed to obtain cell concentration and serum to perform the polymerase chain reaction (PCR) and the indirect immunofluorescence assay (IFA) respectively, in order to identify agents of the Anaplasmataceae family. The data were used for descriptive analysis to obtain frequencies and to perform non-parametric tests with the chi-square test (p≤5%), besides the laboratory findings of infection by Ehrlichia canis, Anaplasma phagocytophilum and Anaplasma platys. The results revealed that 33.33% of the agents belonged to the Anaplasmataceae family, 8.33% for E. canis, 20% for A. platys, and 10% for A. phagocytophilum. Serology samples were examined by indirect immunofluorescence to check samples reacting to A. phagocytophilum, with positive reaction of 8.33%. The most frequent clinical and laboratory findings in patients positive for Anaplasmataceae agents were lethargy, enlargement of lymph nodes, pale mucous membranes, dehydration, thrombocytopenia, hyperglobulinemia and hypoalbuminemia. These data had non-parametric correlation and the laboratory changes and presence of positive cats was not interdependent. Identification of E. canis and A. platys revealed the disease in the region of Campos dos Goytacazes/RJ. The presence of A. phagocytophilum is considered an important finding due to its zoonotic potential.(AU)

Frequency of Equine Monocytic Ehrlichiosis (EME) in Brazil / Relato epidemiológico da Erlichiose monocítica equina (EME) no Brasil

From a cross-sectional observational study with convenience samples, 347 blood samples from horses were collected from different physiographic regions, as follows: Santa Catarina Plateau (Santa Catarina State - SC), Médio Paraíba do Sul (São Paulo State - SP and Rio de Janeiro State RJ), Mountainous and Metropolitan regions (Rio de Janeiro State - RJ). Samples were tested for the presence of antibodies (IgG) anti Neorickettsia risticii by indirect immunofluorescence assay (IFA). The frequency obtained in this study corroborates with the ones obtained in the U.S.A., which refers to endemic regions. Fisher's exact test showed significant differences in the number of positive animals between regions, indicating that the probability of an animal becoming infected varies depending on the area. The CI 95% revealed no association between infection and geopolitical space. Moreover, Odds ratio test showed differences of an animal getting infected in different regions. This event could be influenced by the type of treatment used in each area, as the seasonal frequency of injury or even potential vectors. Therefore, there are seropositive animals for N. risticii in the studied areas, suggesting that this agent may be circulating in those regions. Future studies mainly based on molecular analyzes are needed to confirm these serological findings.

A partir de um delineamento observacional transversal com amostras de conveniência, 347 amostras de sangue foram coletadas de diferentes regiões fisiográficas: Planalto de Santa Catarina (Estado de Santa Catarina - SC), Região do Médio Paraíba do Sul (Estados de São Paulo - SP e Rio de Janeiro - RJ), Região Serrana e Metropolitana (ambas do Estado do Rio de Janeiro - RJ). As amostras foram testadas para a presença de anticorpos (IgG) anti-Neorickettsia risticii por imunofluorescência indireta (IFI). A prevalência obtida no presente estudo corrobora com demais resultados obtidos nos Estados Unidos da América. O Teste Exato de Fisher demonstrou diferença significativa no número de animais positivos entre as regiões, indicando assim que a probabilidade de um animal se infectar varia dependendo da região. O intervalo de confiança (IC 95%) revelou não haver associação entre a infecção e o espaço geopolítico, este evento pode ser influenciado pelo tipo de tratamento em cada área, como sazonalidade do agravo ou frequência de potenciais vetores. Assim, a soropositividade ora encontrada sugere a circulação de N. risticii nas áreas estudadas. Estudos futuros baseados, principalmente, em análises moleculares serão importantes para a confirmação dos achados sorológicos no presente trabalho.

Caamembecaia gratiosus n. gen., n. sp. (Acari: Trombiculidae), from Trinomys gratiosus (Gunter) (Rodentia: Echimydae), of Atlantic forest in southeastern Brazil.

From June 1999 to May 2001, small mammals were captured in three areas of the Atlantic Forest in Southeastern Brazil and examined for ectoparasites. Analysis of ectoparasites revealed the presence of a new chigger genus and species, Caamembecaia gratiosus, from Trinomys gratiosus. This is the first record of a chigger from T. gratiosus.

Associação forética dos ácaros Myialges anchora Sergent & Trouessart (Acaridida, Epidermoptidae) e Ornithocheyletia hallae Smiley (Actinedida, Cheyletiellidae) com Pseudolynchia canariensis (Macquart) (Diptera, Hippoboscidae) / Phoretic association of the mites Myialges anchora Sergent & Trouessart (Acaridida, Epidermoptidae) and Ornithocheyletia hallae Smiley (Actinedida, Cheyletiellidae) with Pseudolynchia canariensis (Macquart) (Diptera, Hippoboscidae)

A partir de 45 espécimes de Pseudolynchia canariensis examinados, foram encontrados 23 deles hiperparasitados por ácaros. É registrada a ocorrência de Myialges anchora e Ornithocheyletia hallae no estado do Rio de Janeiro, Brasil. Dados sobre o grau de infestação desses hipoboscídeos, bem como a distribuição topográfica dos ácaros sobre o corpo desses insetos são brevemente discutidos.

Twenty three louse-flies, from a total of 45 specimens of Pseudolynchia canariensis examined, were found parasitised by mites of the species Myialges anchora and Ornithocheyletia hallae. These mites are recorded for the first time for the State of Rio de Janeiro, in Brazil. Data on levels of infestation, as well as on the topographical distribution of the mites on the body of the louse-flies are briefly discussed.

Caamembecaia gratiosus n. gen., n. sp. (Acari: Trombiculidae), from Trinomys gratiosus (Gunter) (Rodentia: Echimydae), of Atlantic Forest in Southeastern Brazil

From June 1999 to May 2001, small mammals were captured in three areas of the Atlantic Forest in Southeastern Brazil and examined for ectoparasites. Analysis of ectoparasites revealed the presence of a new chigger genus and species, Caamembecaia gratiosus, from Trinomys gratiosus. This is the first record of a chigger from T. gratiosus.

Ocorrencia natural de ornithoica confluenta (hippoboscidae, ornithomyinae) em casmerodius albus no estado de Sao Paulo / Ornithoica confluenta on casmerodius albus in the state of Sao Paulo, Brazil

During the examination of a Great Egret (Casmeridus albus) when captured and taken to the Quinzinho de Barros Municipal Zoo in Sorocaba, state of Sao Paulo, seven arthropod were taken from the bird and put into ethanol at 70ºGL, and afterwards turned over to the Laboratory of Tick Morphophysiology and Pathogeny-Animal Sanity (LMPC-SA), of the Rio de Janeiro Federal Rural University. Animal's Parasite Study Department (DPA/IB/UFRRJ) where they were identified. These arthropod were then classified as belonging to the Hippoboscidae (Diptera, Pupipara) family. To make the genus and species identification possible it was necessary to prepare microscope slides for observation. The hippoboscidae were then identified as Ornithoica confluenta (Say), and sent to the Entomological Collection of the Instituto Oswaldo Cruz. This study is fit into the inter-institutional project that involves the PZMQB and the LMPC-SA/DPA/IB/UFRRJ