Bacterial pathogens' screening in Brazilian chigger mites (Trombidiformes: Trombiculidae), with the first report of 'Candidatus Rickettsia colombianensi'-like in avian-associated chiggers.

Chiggers are larval ectoparasites of the Trombiculidae that can transmit pathogens to their hosts. In this study, chiggers collected from birds in Brazil were morphologically identified as Blankaartia sinnamaryi, Eutrombicula batatas, Eutrombicula daemoni, Eutrombicula goeldii, Eutrombicula tinami, and Parasecia gilbertoi. For these specimens, a beginning attempt at molecular identification were also provided, as well as, were genetically screened to detect bacterial pathogens. The species B. sinnamaryi and E. tinami were positive for Rickettsia felis-like and 'Candidatus Rickettsia colombianensi'-like, respectively. For the other agents (Anaplasmataceae, Borrelia spp. and Orientia tsutsugamushi), the tests were negative. This is the first report of 'Ca. R. colombianensi'-like and the second record of R. felis-like in chigger collected on birds from Brazil.

Bacterial pathogens’ screening in Brazilian chigger mites (Trombidiformes: Trombiculidae), with the first report of 'Candidatus Rickettsia colombianensi'-like in avian-associated chiggers

Chiggers are larval ectoparasites of the Trombiculidae that can transmit pathogens to their hosts. In this study, chiggers collected from birds in Brazil were morphologically identified as Blankaartia sinnamaryi, Eutrombicula batatas, Eutrombicula daemoni, Eutrombicula goeldii, Eutrombicula tinami, and Parasecia gilbertoi. For these specimens, a beginning attempt at molecular identification were also provided, as well as, were genetically screened to detect bacterial pathogens. The species B. sinnamaryi and E. tinami were positive for Rickettsia felis-like and ‘Candidatus Rickettsia colombianensi’-like, respectively. For the other agents (Anaplasmataceae, Borrelia spp. and Orientia tsutsugamushi), the tests were negative. This is the first report of ‘Ca. R. colombianensi’-like and the second record of R. felis-like in chigger collected on birds from Brazil.

Molecular detection of Candidatus Rickettsia colombianensi in ticks (Acari, Ixodidae) collected from herpetofauna in San Juan de Carare, Colombia.

Knowledge about ticks and Rickettsiae in Colombia is still limited and the areas of the country where studies have been conducted are scarce. In this study, ticks (Acari, Ixodidae) associated with reptiles and amphibians in San Juan de Carare, Santander department, were morphologically and molecularly identified and tested for the presence of Rickettsia. For the molecular characterization of ticks, CO1, 12S and 16S sequences were generated and compared with other sequences available in genbank. Our analyses confirmed that the collected ticks were Amblyomma dissimile, and we provide the first report of this species parasitizing the snake Leptodeira septentrionalis. Of the samples analyzed, 69% were positive for Rickettsia sp. using the gltA, ompA and sca1 genes. Rickettsia sequences generated in this study were also compared to sequences downloaded from genbank by Bayesian inference (BI) and maximum likelihood (ML) phylogenetic analyzes. The presence of a single Rickettsia species, Candidatus Rickettsia colombianensi, was identified. This study expands the knowledge regarding the distribution of A. dissimile ticks and Rickettsiae in Colombia.

Molecular detection of Rickettsia genus in chigger mites (Trombidiformes: Trombiculidae) collected on small mammals in southeastern brazilian / Detecção molecular do gênero Rickettsia em ácaros trombiculídeos (Trombidiformes: Trombiculidae) coletados em pequenos mamíferos do sudeste brasileiro

Abstract 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.

Primera detección de Candidatus Rickettsia colombianensi en el departamento del Meta, Colombia / First detection of Candidatus Rickettsia colombianensi in the State of Meta, Colombia

RESUMEN Introducción: Las Rickettsias son un género de bacterias Gram negativas intracelulares obligadas causantes de muchas epidemias en el mundo y son transmitidas principalmente por garrapatas, pulgas, piojos y ácaros. Las rickettsiosis son enfermedades infecciosas reemergentes sin vigilancia epidemiológica en Colombia. Hasta hace pocos años Rickettsia rickettsi era la única Rickettsia transmitida por garrapatas presente en América; sin embargo, nuevas especies están siendo descritas, y aunque su patogenicidad no ha sido confirmada pueden ser consideradas patógenos potenciales. Objetivo: Determinar la presencia de rickettsias en garrapatas del departamento del Meta, Colombia. Material y Métodos: Se realizó un estudio descriptivo de corte transversal, fueron colectadas garrapatas y después de su identificación taxonómica, los genes gltA, ompA y ompB fueron amplificados y secuenciados. Resultados: Se obtuvieron un total de 169 grupos a los que se les realizó PCR de los cuales 2 grupos amplificaron para los genes gltA, ompA y ompB. Conclusiones: Los resultados demuestran la presencia de Rickettsia spp en garrapatas del departamento del Meta.

ABSTRACT Introduction: Rickettsia is a genus of Gram-negative obligate intracellular bacteria that cause several epidemics around the world and are transmitted mainly by ticks, fleas, lice and mites. Rickettsiosis is a re-emergent infectious disease without epidemiological surveillance in Colombia. Until few years ago, Rickettsia rickettsi was the only tick-borne Rickettsioses in America; however, new species are being described, and although their pathogenicity has not been confirmed, they should be considered as potential pathogens. Objective: The aim of this study was to determine the presence of rickettsial agents in ticks in the state of Meta, Colombia. Material and Methods: A descriptive cross-sectional study was conducted; ticks were collected and, after their taxonomic identification, gltA,ompAand ompB genes were amplified and sequenced. Results: A total of 169 pools were obtained to which PCR were carried out, of which 2 PCR were amplified for the gltA, ompA and ompB genes. Conclusions: These results demonstrate the presence of Rickettsia spp in ticks in the State of Meta.

Molecular detection of Rickettsia genus in chigger mites (Trombidiformes: Trombiculidae) collected on small mammals in southeastern brazilian / Detecção molecular do gênero Rickettsia em ácaros trombiculídeos (Trombidiformes: Trombiculidae) coletados em pequenos mamíferos do sudeste brasileiro

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.