Molecular detection of Babesia spp. and Rickettsia spp. in coatis (Nasua nasua) and associated ticks from midwestern Brazil.

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

Historical geographic overlap of human rickettsiosis with animal reservoirs in Juiz de Fora, Minas Gerais, Brazil / Sobreposição geográfica histórica da riquetsiose humana com reservatórios animais em Juiz de Fora, Minas Gerais, Brasil

Background and objectives: we investigated the existence of a historical geographic overlap between the location of spotted fever group rickettsiosis human cases, a disease caused by the gram-negative bacterium Rickettsia sp., and that of mammalian reservoirs, specifically domestic horses and capybaras, in the urban perimeter of the city of Juiz de Fora, Minas Gerais, Brazil. Methods: cases of human rickettsiosis that occurred during a period of 17 years (2003-2020) were geolocated and the distribution of cases in time and geographic space was assessed using 1st and 2nd order geospatial association indicators. We also analyzed the overlap between the locations of human rickettsiosis cases and the area of occurrence of domestic horses and capybaras. Results: men were diagnosed more often than women, but a large proportion of affected women died. The results indicate an aggregation of human rickettsiosis cases in time (cases tend to occur close to each other at each epidemic event) and in geographic space (cases are concentrated in a specific geographic region of the urban perimeter). Human cases seem to be more associated with city regions with: i) higher local frequency of domestic horses and not capybaras; ii) lower rates of family development. Conclusion: it is suggested that, in the local epidemiological scenario, domestic horses appear to be the main sources of the rickettsia infecting humans, not capybaras.(AU)

Justificativa e objetivos: foi investigada a existência de uma sobreposição geográfica histórica entre a localização dos casos de riquetsiose humana do grupo da febre maculosa, um grupo de doenças causadas pela bactéria Gram-negativa Rickettsia sp., e dos reservatórios mamíferos, especificamente cavalos domésticos e capivaras, no perímetro urbano do município de Juiz de Fora, Minas Gerais, Brasil. Métodos: foram geolocalizados os casos de riquetsiose humana ocorridos durante um período de 17 anos (2003-2020), sendo avaliada a distribuição dos casos no tempo e espaço geográfico através de indicadores de associação geoespacial de 1a e 2a ordem. Também analisamos a superposição dos locais dos casos de riquetsiose humana com a área de ocorrência de cavalos domésticos e capivaras. Resultados: homens foram diagnosticados mais frequentemente que as mulheres, mas grande proporção das mulheres acometidas faleceu. Os resultados indicam uma agregação dos casos de riquetsiose humana no tempo (os casos tendem a ocorrer próximos entre si a cada evento epidêmico) e no espaço geográfico (os casos se concentram em uma região geográfica específica do perímetro urbano). Os casos humanos aparentam ser mais associados às regiões da cidade com: i) maior frequência local de cavalos domésticos e não das capivaras; ii) menores índices de desenvolvimento familiar. Conclusão: sugere-se que, no cenário epidemiológico local, são os cavalos domésticos que aparentam ser as principais fontes da riquétsia infectando os humanos, não as capivaras.(AU)

Justificación y objetivos: investigamos la existencia de una superposición geográfica histórica entre la localización de casos de rickettsiosis exantemáticas humana, enfermedad causada por la bacteria gramnegativa Rickettsia sp., y la de mamíferos reservorios, específicamente caballos domésticos y capibaras, en el perímetro urbano de la ciudad de Juiz de Fora, Minas Gerais, Brasil. Métodos: se geolocalizaron los casos de rickettsiosis humana ocurridos durante un período de 17 años (2003-2020), y se evaluó la distribución de casos en el tiempo y espacio geográfico utilizando indicadores de asociación geoespacial de 1er y 2do orden. También analizamos la superposición entre las ubicaciones de los casos de rickettsiosis humana y el área de ocurrencia de los caballos domésticos y capibaras. Resultados: los hombres fueron diagnosticados con más frecuencia que las mujeres, pero una gran proporción de mujeres afectadas fallecieron. Los resultados indican una agregación de casos de rickettsiosis humana en el tiempo (los casos tienden a ocurrir cerca uno del otro en cada evento epidémico) y en el espacio geográfico (los casos se concentran en una región geográfica específica del perímetro urbano). Los casos humanos parecen estar más asociados con regiones urbanas con: i) mayor frecuencia local de caballos domésticos y no de capibaras; ii) menores tasas de desarrollo familiar. Conclusión: se sugiere que, en el escenario epidemiológico local, los caballos domésticos parecen ser las principales fuentes de la rickettsia que infecta a los humanos, no los capibaras.(AU)

Molecular detection of vector-borne agents in wild boars (Sus scrofa) and associated ticks from Brazil, with evidence of putative new genotypes of Ehrlichia, Anaplasma, and haemoplasmas.

The present study aimed to investigate, by molecular techniques, the occurrence of Anaplasmataceae, Bartonellaceae, Rickettsiaceae, Mycoplasmataceae, Coxiellaceae, and Babesiidae/Theileriidae agents in blood samples of free-living wild boars (Sus scrofa) and associated ticks in south-eastern Brazil. For this purpose, 67 blood samples and 265 ticks (264 Amblyomma sculptum and one Amblyomma ovale) were analysed. In the screening for Anaplasmataceae agents by a PCR assay based on the 16S rRNA gene, 5.97% blood samples and 50.54% ticks were positive. In the PCR assay for Ehrlichia spp. based on the dsb gene, 9.24% of ticks were positive. Despite the low occurrence, a possible new 16S rRNA genotype of Anaplasma sp. was detected in a wild boar's blood sample. According to phylogenetic analyses based on the 16S rRNA, gltA, and sodB genes and ITS (23S-5S rRNA) intergenic region, it was found that A. sculptum and A. ovale ticks collected from wild boars carry Ehrlichia genotypes phylogenetically associated with Ehrlichia ewingii, Ehrlichia ruminantium, and new Ehrlichia genotypes previously detected in horses, peccaries, and ticks collected from jaguars. In the screening for haemoplasmas by a qPCR based on the 16S rRNA gene, 88.06% of blood samples and 8.69% of ticks were positive. Mycoplasma suis, Mycoplasma parvum, and a possible new haemoplasma genotype were detected in wild boars in south-eastern Brazil. In the screening for Bartonella spp. using a nuoG-based qPCR assay, 3.8% of tick samples were positive. Phylogenetic inferences positioned four nuoG and one r gltA Bartonella sequences into the same clade as Bartonella machadoae. No blood or tick samples from wild boars showed to be positive in the qPCR for Coxiella burnetii based on the IS1111 gene. On the other hand, only 1.6% of ticks were positive in the nested PCR assay for piroplasmids based on the 18S rRNA gene. A 18S rRNA sequence detected in a pool of A. sculptum nymphs was phylogenetically close to Cytauxzoon felis sequences previously detected in cats from the United States. Rickettsia sp. closely related to Rickettsia bellii was detected in a pool of A. sculptum nymphs. This is the first report of haemoplasmas, B. machadoae, and Cytauxzoon spp. in A. sculptum. Wild boars and associated ticks do not seem to participate in the epidemiological cycle of C. burnetii in the region studied. This invasive mammal species may act as a potential disperser of ticks infected with Ehrlichia spp., Bartonella spp., haemotropic mycoplasmas, and Cytauxzoon, and may bring important epidemiological implications in the transmission of bartonelosis, ehrlichiosis, haemoplasmosis, and cytauxzoonosis to humans and animals, more specifically to horses, rodents, pigs, and cats.

First molecular detection of Rickettsia sp. strain Atlantic rainforest in Amblyomma ovale ticks from Espírito Santo state, Brazil / Primeira detecção molecular da Rickettsia sp. cepa Mata Atlântica em carrapatos Amblyomma ovale do estado do Espírito Santo, Brasil

Espírito Santo state (southeastern Brazil) is considered an endemic area for spotted fever group rickettsioses. In February 2017, we received in our laboratory seven unfed Amblyomma ovale adult ticks collected by a farmer from his clothes and body (not attached) during a working day in the rural area of Ibiraçu municipality, Espírito Santo state. By polymerase chain reaction (PCR) analyses, targeting gltA and ompA rickettsial genes, the DNA of Rickettsia was detected in 6/7 (85.7%) A. ovale. In all cases, DNA sequencing of PCR products revealed that consensus sequences of both genes were 100% identical to gltA and ompA corresponding sequences of Rickettsia sp. strain Atlantic rainforest retrieved from GenBank. This study reports the first molecular detection of Rickettsia sp. strain Atlantic rainforest in A. ovale ticks from Espírito Santo state. Our findings indicate a new Brazilian state in the southeast region at risk of human infection with this tick-borne emerging rickettsial agent.(AU)

O estado do Espírito Santo (Sudeste do Brasil) é considerado área endêmica para riquetsioses do Grupo Febre Maculosa. Em fevereiro de 2017, recebemos em nosso laboratório sete carrapatos adultos Amblyomma ovale não ingurgitados, coletados por um fazendeiro nas suas roupas e corpo (não fixadas) durante um dia de trabalho, em área rural do municipio de Ibiraçu, estado do Espírito Santo. Por meio de reação em cadeia da polimerase (PCR), amplificando os genes riquetsiais gltA e ompA , foi detectado ADN de Rickettsia em 6/7 (85,7%) dos A. ovale . O sequenciamento dos produtos de PCR indicou que as sequências consenso de ambos genes foram 100% idênticos às sequências correspondentes dos genes gltA e ompA da Rickettsia sp. cepa Mata Atlântica recuperadas do GenBank. Este estudo relata a primeira detecção molecular da Rickettsia sp. cepa Mata Atlântica em carrapatos A. ovale do estado do Espírito Santo. Nossos resultados apontam um novo estado brasileiro da região Sudeste com risco de infecção humana por este agente rickettsial emergente transmitido por carrapatos.(AU)

First molecular detection of Rickettsia sp. strain Atlantic rainforest in Amblyomma ovale ticks from Espírito Santo state, Brazil / Primeira detecção molecular da Rickettsia sp. cepa Mata Atlântica em carrapatos Amblyomma ovale do estado do Espírito Santo, Brasil

Abstract Espírito Santo state (southeastern Brazil) is considered an endemic area for spotted fever group rickettsioses. In February 2017, we received in our laboratory seven unfed Amblyomma ovale adult ticks collected by a farmer from his clothes and body (not attached) during a working day in the rural area of Ibiraçu municipality, Espírito Santo state. By polymerase chain reaction (PCR) analyses, targeting gltA and ompA rickettsial genes, the DNA of Rickettsia was detected in 6/7 (85.7%) A. ovale. In all cases, DNA sequencing of PCR products revealed that consensus sequences of both genes were 100% identical to gltA and ompA corresponding sequences of Rickettsia sp. strain Atlantic rainforest retrieved from GenBank. This study reports the first molecular detection of Rickettsia sp. strain Atlantic rainforest in A. ovale ticks from Espírito Santo state. Our findings indicate a new Brazilian state in the southeast region at risk of human infection with this tick-borne emerging rickettsial agent.

Resumo O estado do Espírito Santo (Sudeste do Brasil) é considerado área endêmica para riquetsioses do Grupo Febre Maculosa. Em fevereiro de 2017, recebemos em nosso laboratório sete carrapatos adultos Amblyomma ovale não ingurgitados, coletados por um fazendeiro nas suas roupas e corpo (não fixadas) durante um dia de trabalho, em área rural do municipio de Ibiraçu, estado do Espírito Santo. Por meio de reação em cadeia da polimerase (PCR), amplificando os genes riquetsiais gltA e ompA , foi detectado ADN de Rickettsia em 6/7 (85,7%) dos A. ovale . O sequenciamento dos produtos de PCR indicou que as sequências consenso de ambos genes foram 100% idênticos às sequências correspondentes dos genes gltA e ompA da Rickettsia sp. cepa Mata Atlântica recuperadas do GenBank. Este estudo relata a primeira detecção molecular da Rickettsia sp. cepa Mata Atlântica em carrapatos A. ovale do estado do Espírito Santo. Nossos resultados apontam um novo estado brasileiro da região Sudeste com risco de infecção humana por este agente rickettsial emergente transmitido por carrapatos.

Detection of Rickettsia spp. in ticks parasitizing toads (Rhinella marina) in the northern Brazilian Amazon.

This study evaluated rickettsial infection in ticks collected on toads from the northern Brazilian Amazon (Amapá state), where to our knowledge there are neither records of ticks from amphibians nor rickettsial infections in ticks. During 2016-2017, a total of 22 free-living toads were captured and identified as Rhinella marina. Overall, 12 (54.5%) toads were parasitized by a total of 97 ticks (6 males, 39 females, 31 nymphs, 21 larvae), giving a mean intensity of 8.1 ticks per infested toad. Two tick species were morphologically identified: Amblyomma rotundatum Koch (31 females, 14 nymphs), and Amblyomma dissimile Koch (6 males, 8 females, 17 nymphs). The 21 larvae were morphologically denoted as Amblyomma sp. Five toads were co-infested by A. rotundatum and A. dissimile. Morphological identifications were confirmed by nucleotide sequencing of fragments of the mitochondrial genes 16S rDNA, 12S rDNA and/or COX1. A total of 54 ticks were analyzed for the presence of rickettsial DNA. Eleven (9 females and 2 nymphs) out of 14 A. rotundatum ticks contained Rickettsia bellii. None of the 25 specimens of A. dissimile (6 males, 6 females, 13 nymphs) contained amplifiable rickettsial DNA. From 15 Amblyomma sp. larvae, a pool of 10 individuals contained Rickettsia sp. strain Colombianensi. Sequencing of the 16S rDNA amplicon derived from the positive pool yielded a sequence of A. dissimile. We detected Rickettsia sp. strain Colombianensi for the first time in Brazil. Prior records of this agent were restricted to Colombia and Honduras. In addition, we report the presence of A. rotundatum for the first time in the state of Amapá, where the only other record of A. dissimile was registered over 20 years ago.

Detecção de proteínas imunorreativas de Rickettsia sp. cepa Mata Atlântica / Detection of immunoreactive proteins of Rickettsia sp. Atlantic Forest strain

Brazilian Spotted Fever (BSF) is an infectious disease transmitted by ticks to humans. A new human rickettsial infection was reported to cause spotted fever in the State of São Paulo and was named Rickettsia sp. Strain Atlantic Forest. This study aimed to detect and identify proteins with potential to stimulate the immune system of mammalian host of this new strain described. Therefore, we performed total protein extraction Rickettsia sp. Strain Atlantic Forest. The extracted proteins were fractionated by electrophoresis. The protein bands were transferred to nitrocellulose membrane by electrical migration and subjected to Western blot for protein detection. In all, seven immunoreactive proteins were detected. Two proteins showed higher abundance, with molecular weight of 200 and 130 kDa respectively. By comparing existing proteomic maps and the molecular weight of these proteins showed that, it is suggested that the two proteins detected representing rOmpA (200 kDa) and rOmpB (130 kDa). The other detected proteins had lower occurrence and molecular weight less than 78 kDa, which may represent members of the cell surface antigens Family (Sca - Surface cell antigen). The detected proteins may serve as a study based on the development of sensitive and specific diagnostic methods in the development of vaccines and they enable further studies to more effective therapies.(AU)

A Febre Maculosa Brasileira (FMB) é uma doença infecciosa, transmitida por carrapatos ao homem. Uma nova riquetsiose humana foi descrita como causadora de Febre Maculosa no Estado de São Paulo, sendo denominada de Rickettsia sp. cepa Mata Atlântica. O presente trabalho teve como objetivo detectar e identificar proteínas com potencial de estimular o sistema imune de hospedeiro mamífero, desta nova cepa descrita. Para tanto, foi realizado a extração proteica total de Rickettsia sp. cepa Mata Atlântica. As proteínas extraídas foram fracionadas por eletroforese. As bandas proteicas foram transferidas para membranas de nitrocelulose por migração elétrica e submetidas à técnica de Western-blot, para detecção proteica. Ao todo sete proteínas imunorreativas foram detectadas. Duas proteínas apresentaram maior abundancia, com peso molecular, de 200 e 130 kDa respectivamente. Através da comparação de mapas proteômicos existentes e pelo peso molecular que estas proteínas apresentaram, sugere-se que as duas proteínas detectadas representem rOmpA (200 kDa) e rOmpB (130 kDa). As demais proteínas detectadas apresentaram menor ocorrência e peso molecular inferior a 78 kDa, podendo representar membros da família de antígenos de superfície celular (Sca - Surface cell antigen). As proteínas detectadas poderão servir como base de estudo na elaboração de métodos diagnósticos sensíveis e específicos, no desenvolvimento de vacinas, além de possibilitarem novos estudos para terapias mais eficazes.(AU)

Detecção de proteínas imunorreativas de Rickettsia sp. cepa Mata Atlântica / Detection of immunoreactive proteins of Rickettsia sp. Atlantic Forest strain

A Febre Maculosa Brasileira (FMB) é uma doença infecciosa, transmitida por carrapatos ao homem. Uma nova riquetsiose humana foi descrita como causadora de Febre Maculosa no Estado de São Paulo, sendo denominada de Rickettsia sp. cepa Mata Atlântica. O presente trabalho teve como objetivo detectar e identificar proteínas com potencial de estimular o sistema imune de hospedeiro mamífero, desta nova cepa descrita. Para tanto, foi realizado a extração proteica total de Rickettsia sp. cepa Mata Atlântica. As proteínas extraídas foram fracionadas por eletroforese. As bandas proteicas foram transferidas para membranas de nitrocelulose por migração elétrica e submetidas à técnica de Western-blot, para detecção proteica. Ao todo sete proteínas imunorreativas foram detectadas. Duas proteínas apresentaram maior abundancia, com peso molecular, de 200 e 130 kDa respectivamente. Através da comparação de mapas proteômicos existentes e pelo peso molecular que estas proteínas apresentaram, sugere-se que as duas proteínas detectadas representem rOmpA (200 kDa) e rOmpB (130 kDa). As demais proteínas detectadas apresentaram menor ocorrência e peso molecular inferior a 78 kDa, podendo representar membros da família de antígenos de superfície celular (Sca - Surface cell antigen). As proteínas detectadas poderão servir como base de estudo na elaboração de métodos diagnósticos sensíveis e específicos, no desenvolvimento de vacinas, além de possibilitarem novos estudos para terapias mais eficazes.(AU)

Brazilian Spotted Fever (BSF) is an infectious disease transmitted by ticks to humans. A new human rickettsial infection was reported to cause spotted fever in the State of São Paulo and was named Rickettsia sp. Strain Atlantic Forest. This study aimed to detect and identify proteins with potential to stimulate the immune system of mammalian host of this new strain described. Therefore, we performed total protein extraction Rickettsia sp. Strain Atlantic Forest. The extracted proteins were fractionated by electrophoresis. The protein bands were transferred to nitrocellulose membrane by electrical migration and subjected to Western blot for protein detection. In all, seven immunoreactive proteins were detected. Two proteins showed higher abundance, with molecular weight of 200 and 130 kDa respectively. By comparing existing proteomic maps and the molecular weight of these proteins showed that, it is suggested that the two proteins detected representing rOmpA (200 kDa) and rOmpB (130 kDa). The other detected proteins had lower occurrence and molecular weight less than 78 kDa, which may represent members of the cell surface antigens Family (Sca - Surface cell antigen). The detected proteins may serve as a study based on the development of sensitive and specific diagnostic methods in the development of vaccines and they enable further studies to more effective therapies.(AU)

Detecção de proteínas imunorreativas de Rickettsia sp. cepa Mata Atlântica

ABSTRACT: Brazilian Spotted Fever (BSF) is an infectious disease transmitted by ticks to humans. A new human rickettsial infection was reported to cause spotted fever in the State of São Paulo and was named Rickettsia sp. Strain Atlantic Forest. This study aimed to detect and identify proteins with potential to stimulate the immune system of mammalian host of this new strain described. Therefore, we performed total protein extraction Rickettsia sp. Strain Atlantic Forest. The extracted proteins were fractionated by electrophoresis. The protein bands were transferred to nitrocellulose membrane by electrical migration and subjected to Western blot for protein detection. In all, seven immunoreactive proteins were detected. Two proteins showed higher abundance, with molecular weight of 200 and 130 kDa respectively. By comparing existing proteomic maps and the molecular weight of these proteins showed that, it is suggested that the two proteins detected representing rOmpA (200 kDa) and rOmpB (130 kDa). The other detected proteins had lower occurrence and molecular weight less than 78 kDa, which may represent members of the cell surface antigens Family (Sca - Surface cell antigen). The detected proteins may serve as a study based on the development of sensitive and specific diagnostic methods in the development of vaccines and they enable further studies to more effective therapies.

RESUMO: A Febre Maculosa Brasileira (FMB) é uma doença infecciosa, transmitida por carrapatos ao homem. Uma nova riquetsiose humana foi descrita como causadora de Febre Maculosa no Estado de São Paulo, sendo denominada de Rickettsia sp. cepa Mata Atlântica. O presente trabalho teve como objetivo detectar e identificar proteínas com potencial de estimular o sistema imune de hospedeiro mamífero, desta nova cepa descrita. Para tanto, foi realizado a extração proteica total de Rickettsia sp. cepa Mata Atlântica. As proteínas extraídas foram fracionadas por eletroforese. As bandas proteicas foram transferidas para membranas de nitrocelulose por migração elétrica e submetidas à técnica de Western-blot, para detecção proteica. Ao todo sete proteínas imunorreativas foram detectadas. Duas proteínas apresentaram maior abundancia, com peso molecular, de 200 e 130 kDa respectivamente. Através da comparação de mapas proteômicos existentes e pelo peso molecular que estas proteínas apresentaram, sugere-se que as duas proteínas detectadas representem rOmpA (200 kDa) e rOmpB (130 kDa). As demais proteínas detectadas apresentaram menor ocorrência e peso molecular inferior a 78 kDa, podendo representar membros da família de antígenos de superfície celular (Sca - Surface cell antigen). As proteínas detectadas poderão servir como base de estudo na elaboração de métodos diagnósticos sensíveis e específicos, no desenvolvimento de vacinas, além de possibilitarem novos estudos para terapias mais eficazes.

Ecology of a tick-borne spotted fever in southern Brazil.

Rio Grande do Sul is the southernmost state of Brazil, bordering Uruguay. Clinical cases of spotted fever group (SFG) rickettsiosis were recently reported in Rio Grande do Sul. None of these cases was lethal, and all were confirmed by seroconversion to R. rickettsii antigens. Because serological cross-reactions are well known to occur between different SFG agents, the SFG agent responsible for the clinical cases remains unknown in Rio Grande do Sul, where no rickettsial agent is known to infect ticks. During 2013-2014, ticks and blood sera samples were collected from domestic dogs and wild small mammals, and from the vegetation in a SFG-endemic area of Rio Grande do Sul. Dogs were infested by Amblyomma ovale adult ticks, whereas small mammals were infested by immature stages of A. ovale, Ixodes loricatus, and adults of I. loricatus. Ticks collected on vegetation were adults of A. ovale, and immature stages of A. ovale, Amblyomma dubitatum, and Amblyomma longirostre. Three Rickettsia species were detected: Rickettsia bellii in I. loricatus, Rickettsia amblyommii in A. longirostre, and a Rickettsia parkeri-like agent (Rickettsia sp. strain Atlantic rainforest) in A. ovale. Seroreactivity to SFG antigens were detected in 19.7 % (27/137) canine and 37.5 % (15/40) small mammal sera, with highest titers to R. parkeri. Results indicate that the R. parkeri-like agent, strain Atlantic rainforest, is circulating between A. ovale ticks, dogs and small mammals in the study area, suggesting that this SFG pathogen could be one of the etiological agents of SFG clinical cases in Rio Grande do Sul.

Genetic identification of Rickettsia sp. strain Atlantic rainforest in an endemic area of a mild spotted fever in Rio Grande do Sul state, Southern Brazil.

Rickettsia sp. strain Atlantic rainforest causes a less severe rickettsiosis, with two cases confirmed until now. The tick species Amblyomma ovale is appointed as the main vector of this bacterium. The southern region of Brazil has reported patients with spotted fever who have milder symptoms. In 2013, during an investigation of rickettsiosis cases, an A. ovale tick was found attached to a man in an area where there were two cases. The parasite was processed for molecular analysis and the rickettsial infection was confirmed based on phylogenetic analysis of genes ompA, ompB and geneD (sca4). In the present study the human pathogenic Rickettsia sp. strain Atlantic rainforest was identified in the state of Rio Grande do Sul, Southern Brazil. Since A. ovale, its main vector, is found frequently parasitizing dogs, animals that can cross international borders freely in southern Brazil, this bacteria can bring major concerns in terms of public health.

Molecular detection of the human pathogenic Rickettsia sp. strain Atlantic rainforest in Amblyomma dubitatum ticks from Argentina.

To date, three tick-borne pathogenic Rickettsia species have been reported in different regions of Argentina, namely, R. rickettsii, R. parkeri, and R. massiliae. However, there are no reports available for the presence of tick-borne pathogens from the northeastern region of Argentina. This study evaluated the infection with Rickettsia species of Amblyomma dubitatum ticks collected from vegetation and feeding from capybaras (Hydrochoerus hydrochaeris) in northeastern Argentina. From a total of 374 A. dubitatum ticks collected and evaluated by PCR for the presence of rickettsial DNA, 19 were positive for the presence of Rickettsia bellii DNA, two were positive for Rickettsia sp. strain COOPERI, and one was positive for the pathogenic Rickettsia sp. strain Atlantic rainforest. To our knowledge, this study is the first report of the presence of the human pathogen Rickettsia sp. strain Atlantic rainforest and Rickettsia sp. strain COOPERI in Argentina. Moreover, our findings posit A. dubitatum as a potential vector for this pathogenic strain of Rickettsia.

Infection of Amblyomma ovale by Rickettsia sp. strain Atlantic rainforest, Colombia.

Our goal was to understand rickettsial spotted fevers' circulation in areas of previous outbreaks reported from 2006 to 2008 in Colombia. We herein present molecular identification and isolation of Rickettsia sp. Atlantic rainforest strain from Amblyomma ovale ticks, a strain shown to be pathogenic to humans. Infected ticks were found on dogs and a rodent in Antioquia and Córdoba Provinces. This is the first report of this rickettsia outside Brazil, which expands its known range considerably.