Infestação por carrapatos Argasidae e Ixodidae em pequenos mamíferos silvestres da Estação Experimental Rafael Fernandes, Mossoró/RN / Infestation by ticks Argasidae and Ixodidae on small wild mammals at the Experimental Station Rafael Fernandes, Mossoró/RN, Brazil

Poucos estudos avaliaram a diversidade de ectoparasitos e a associação deles com seus hospedeiros que ocorrem no bioma Caatinga, Nordeste do Brasil. Considerando-se essa falta de conhecimento, este estudo objetivou identificar e determinar a ocorrência de carrapatos coletados de pequenos mamíferos da Estação Experimental Rafael Fernandes, no Rio Grande do Norte, Brasil. De janeiro de 2014 a fevereiro de 2015 foram capturados 52 marsupiais (38 Gracilinanus agilis e 14 Monodelphis domestica) e 10 roedores (5 Wiedomys sp., 4 Thrichomys sp. e 1 Rattus norvegicus). Foram identificados os carrapatos Amblyomma auricularium, Amblyomma parvum, Amblyomma sp., Ornithodoros mimon e Ornithodoros sp., empregando estudo morfológico, chaves taxonômicas e sequenciamento parcial do gene mitocondrial 16S rDNA de carrapatos. Todas as associações carrapato-hospedeiro encontradas neste estudo são relatadas pela primeira vez no Rio Grande do Norte e constituem novos dados ecológicos aplicáveis aos ectoparasitos de pequenos mamíferos no nordeste do Brasil.(AU)

Few studies have assessed the diversity of ectoparasites and their associated hosts occurring within the Caatinga biome in northeastern Brazil. Considering this lack of knowledge, in this study we aimed to identify and determine the occurrence of ticks collected from small mammals at the Estação Experimental Rafael Fernandes, in Rio Grande do Norte state, Brazil. From January 2014 to February 2015, we captured 52 marsupials (38 Gracilinanus agilis and 14 Monodelphis domestica) and 10 rodents (5 Wiedomys sp., 4 Thrichomys sp. and 1 Rattus norvegicus). We identified the ticks Amblyomma auricularium, Amblyomma parvum, Amblyomma sp., Ornithodoros mimon and Ornithodoros sp. by a morphological study, the use of taxonomic keys, and the partial sequencing of the tick mitochondrial 16S rDNA gene. All the tick-host associations found in this study are reported for the first time in Rio Grande do Norte and constitute new ecological data concerning ectoparasites of small mammals in northeastern Brazil.(AU)

Infestação por carrapatos Argasidae e Ixodidae em pequenos mamíferos silvestres da Estação Experimental Rafael Fernandes, Mossoró/RN / Infestation by ticks Argasidae and Ixodidae on small wild mammals at the Experimental Station Rafael Fernandes, Mossoró/RN, Brazil

Poucos estudos avaliaram a diversidade de ectoparasitos e a associação deles com seus hospedeiros que ocorrem no bioma Caatinga, Nordeste do Brasil. Considerando-se essa falta de conhecimento, este estudo objetivou identificar e determinar a ocorrência de carrapatos coletados de pequenos mamíferos da Estação Experimental Rafael Fernandes, no Rio Grande do Norte, Brasil. De janeiro de 2014 a fevereiro de 2015 foram capturados 52 marsupiais (38 Gracilinanus agilis e 14 Monodelphis domestica) e 10 roedores (5 Wiedomys sp., 4 Thrichomys sp. e 1 Rattus norvegicus). Foram identificados os carrapatos Amblyomma auricularium, Amblyomma parvum, Amblyomma sp., Ornithodoros mimon e Ornithodoros sp., empregando estudo morfológico, chaves taxonômicas e sequenciamento parcial do gene mitocondrial 16S rDNA de carrapatos. Todas as associações carrapato-hospedeiro encontradas neste estudo são relatadas pela primeira vez no Rio Grande do Norte e constituem novos dados ecológicos aplicáveis aos ectoparasitos de pequenos mamíferos no nordeste do Brasil.(AU)

Few studies have assessed the diversity of ectoparasites and their associated hosts occurring within the Caatinga biome in northeastern Brazil. Considering this lack of knowledge, in this study we aimed to identify and determine the occurrence of ticks collected from small mammals at the Estação Experimental Rafael Fernandes, in Rio Grande do Norte state, Brazil. From January 2014 to February 2015, we captured 52 marsupials (38 Gracilinanus agilis and 14 Monodelphis domestica) and 10 rodents (5 Wiedomys sp., 4 Thrichomys sp. and 1 Rattus norvegicus). We identified the ticks Amblyomma auricularium, Amblyomma parvum, Amblyomma sp., Ornithodoros mimon and Ornithodoros sp. by a morphological study, the use of taxonomic keys, and the partial sequencing of the tick mitochondrial 16S rDNA gene. All the tick-host associations found in this study are reported for the first time in Rio Grande do Norte and constitute new ecological data concerning ectoparasites of small mammals in northeastern Brazil.(AU)

Infestação por carrapatos Argasidae e Ixodidae em pequenos mamíferos silvestres da Estação Experimental Rafael Fernandes, Mossoró/RN

ABSTRACT: Few studies have assessed the diversity of ectoparasites and their associated hosts occurring within the Caatinga biome in northeastern Brazil. Considering this lack of knowledge, in this study we aimed to identify and determine the occurrence of ticks collected from small mammals at the Estação Experimental Rafael Fernandes, in Rio Grande do Norte state, Brazil. From January 2014 to February 2015, we captured 52 marsupials (38 Gracilinanus agilis and 14 Monodelphis domestica) and 10 rodents (5 Wiedomys sp., 4 Thrichomys sp. and 1 Rattus norvegicus). We identified the ticks Amblyomma auricularium, Amblyomma parvum, Amblyomma sp., Ornithodoros mimon and Ornithodoros sp. by a morphological study, the use of taxonomic keys, and the partial sequencing of the tick mitochondrial 16S rDNA gene. All the tick-host associations found in this study are reported for the first time in Rio Grande do Norte and constitute new ecological data concerning ectoparasites of small mammals in northeastern Brazil.

RESUMO: Poucos estudos avaliaram a diversidade de ectoparasitos e a associação deles com seus hospedeiros que ocorrem no bioma Caatinga, Nordeste do Brasil. Considerando-se essa falta de conhecimento, este estudo objetivou identificar e determinar a ocorrência de carrapatos coletados de pequenos mamíferos da Estação Experimental Rafael Fernandes, no Rio Grande do Norte, Brasil. De janeiro de 2014 a fevereiro de 2015 foram capturados 52 marsupiais (38 Gracilinanus agilis e 14 Monodelphis domestica) e 10 roedores (5 Wiedomys sp., 4 Thrichomys sp. e 1 Rattus norvegicus). Foram identificados os carrapatos Amblyomma auricularium, Amblyomma parvum, Amblyomma sp., Ornithodoros mimon e Ornithodoros sp., empregando estudo morfológico, chaves taxonômicas e sequenciamento parcial do gene mitocondrial 16S rDNA de carrapatos. Todas as associações carrapato-hospedeiro encontradas neste estudo são relatadas pela primeira vez no Rio Grande do Norte e constituem novos dados ecológicos aplicáveis aos ectoparasitos de pequenos mamíferos no nordeste do Brasil.

PEQUENOS MAMÍFEROS NÃO VOADORES NO VALE DO RIO PARANAÍBA, BRASIL: MANUTENÇÃO DE LEPTOSPIRAS PATOGÊNICAS E CARRAPATOS

O rio Paranaíba está localizado predominantemente no bioma Cerrado, com algumas manchas de Mata Atlântica. Os pequenos mamíferos são modelos aplicáveis no estudo de carrapatos e circulação de patógenos, inclusive em ambientes com diferentes graus de degradação. O presente estudo descreve as diferentes espécies de pequenos mamíferos não voadores no vale do rio Paranaíba, e a identificação destes como portadores renais de leptospiras patogênicas; investiga o papel de pequenos mamíferos não voadores silvestres e sinantrópicos na ecologia da leptospirose em uma propriedade rural na região sudeste do estado de Goiás e avalia o papel desses animais como hospedeiros para carrapatos em áreas de Cerrado no vale do rio Paranaíba. Foram capturados 72 pequenos mamíferos não voadores de três espécies de marsupiais (36,1%, 38 espécimes) e oito espécies de roedores (63,9%, 46 espécimes). Do total, 24 (33,33%) estavam positivos à PCR do gene lipL32 e apenas um espécime de marsupial, Gracilinanus agilis, foi reagente à técnica de aglutinação microscópica (MAT) para o sorovar Australis na diluição de 1/100. Frente a PCR, 10 roedores (34,48%) e 14 marsupiais (32,56%) foram positivos. Bovinos de propriedade na região sudeste do estado de Goiás reagiram principalmente para estirpes pertencentes ao sorogrupo Icterohaemorrhagiae, adaptados às espécies de pequenos mamíferos. Do total de pequenos mamíferos capturados, apenas 14 espécimes, correspondentes aos gêneros Nectomys, Cerradomys, Oecomys, Necromys e Gracilinanus estavam infestados por carrapatos. A riqueza de carrapatos foi de pelo menos 04 espécies no Alto Paranaíba (Ixodes sp., Ornithodoros sp., Amblyomma dubitatum, Amblyomma sculptum), além de larvas de Amblyomma sp.; 02 no Médio Paranaíba (Ornithodoros sp. e Amblyomma dubitatum) e larvas de Amblyomma sp.; e apenas 01 no Baixo Paranaíba (Ornithodoros sp.). Pequenos mamíferos não voadores cumprem o papel de veiculadores de leptospiras patogênicas no vale do rio Paranaíba. Este é o primeiro relato de identificação, via PCR, de Gracilinanus agilis, Calomys sp., Hylaeamys megacephalus e Oecomys bicolor como portadores renais e veiculadores de leptospiras patogênicas. Pequenos mamíferos desempenham relevante papel na ecologia da leptospirose em propriedade rural produtora de leite, favorecendo a infecção de bovinos. Carrapatos do gênero Ornithodoros sp. foram encontrados parasitando apenas o didelfídeo Gracilinanus agilis. O carrapato da espécie Amblyomma dubitatum foi o de maior ocorrência em pequenos mamíferos do vale do rio Paranaíba e este parece ser o primeiro registro desta espécie em Nectomys sp. no bioma Cerrado. Como também o primeiro registo de Ixodes loricatus parasitando Cerradomys sp. e Ixodes loricatus em Rhipidomys sp. no Brasil.

The Paranaibas river is located predominantly without Cerrado biome, with some spots of Atlantic Forest. Small mammals are models and no study of ticks and circulation of pathogens, even in environments with different degrees of degradation. The present study describes the different species of small non-flying mammals in the Paranaíba River valley, and their identification as renal carriers of pathogenic leptospiras. Investigates the role of small non-flying wild and synanthropic mammals in the ecology of leptospirosis in a rural property in the southeastern region of the state of Goiás. In addition, evaluates the role of these animals as hosts for ticks in Cerrado areas, in the Paranaíba river valley. Seventy-two small non-flying mammals were captured from three species of marsupials and eight rodent species. Of these 72, 24 (33.33%) were positive for lipL32 gene PCR and only one specimen, Gracilinanus agilis, was MAT reagent for serovar Australis. Among the marsupials, 14 (32.56%) were PCR positive, and 10 rodent specimens (34.48%) were diagnosed as renal carriers by the same technique. Cattle owned in the southeastern region of the state of Goiás reacted mainly to strains belonging to the serogroup Icterohaemorrhagiae, maintained by small mammals. Of the total of small mammals captured, ticks infested only 14 animals, corresponding to the genera Nectomys, Cerradomys, Oecomys, Necromys and Gracilinanus. The tick richness was at least 04 species in the Alto Paranaíba (Ixodes sp., Ornithodoros sp., Amblyomma dubitatum, Amblyomma sculptum) in addition to Amblyomma sp. 02 in the Middle Paranaíba (Ornithodoros sp. and Amblyomma dubitatum), and Amblyomma sp. and only 01 in the Low Paranaíba (Ornithodoros sp.). Small non-flying mammals play a role of pathogenic leptospires carriers in the Paranaíba river valley. This is the first report of PCR identification of Gracilinanus agilis, Calomys sp., Hylaeamys megacephala and Oecomys bicolor as renal carriers of pathogenic leptospires. Small mammals play a relevant role in the ecology of leptospirosis in rural dairy farms, favoring the infection of cattle. Ticks of the genus Ornithodoros sp. were found parasitizing only the didelid Gracilinanus sp. The Ambliomma dubitatum tick was the most frequent occurrence in small mammals in the Paranaíba river valley, and this seems to be the first record of this species in Nectomys sp. in the Cerrado biome. As well as the first, record of Ixodes loricatus parasitizing Cerradomys sp., and the first record of Ixodes loricatus in Rhipidomys sp. in Brazil.

Population ecology of small rodents and marsupials in a semi-deciduous tropical forest of the southeast Pantanal, Brazil

The Pantanal is a South American biome characterized by extensive plains and stark environmental seasonality. Several habitats are subject to annual flooding, forcing small mammal species to aggregate in dry forest patches, which most likely influences their population dynamics and life history strategies. In order to investigate the seasonal influence on the life history traits of these small mammals, we conducted a 2-year mark-recapture study in the southeastern region of the Brazilian Pantanal (Nhecolândia) and analyzed the population dynamics of the most abundant small mammal species with the jackknife estimator. A trapping effort of 21,560 trap-nights resulted in 615 individuals in 1,171 captures (success = 5.43%). Three species of rodents - Oecomys mamorae (Thomas, 1906), Thrichomys pachyurus (Wagner, 1845), and Clyomys laticeps (Thomas, 1841) - and three species of marsupials - Gracilinanus agilis (Burmeister, 1854), Thylamys macrurus (Olfers, 1818), and Monodelphis domestica (Wagner, 1842) - were obtained. The most abundant species was O. mamorae, followed by G. agilis and T. pachyurus. Oecomys mamorae was more abundant in the wet season and presented an opportunistic reproductive strategy. Gracilianus agilis displayed increased population sizes in the dry season and synchronized, seasonal reproduction during the rainy season. Thrichomys pachyurus had a small population size, delayed response to variations in environmental conditions and higher reproductive rates in the dry season. All species revealed different life history strategies (seasonal, opportunistic or delayed response to environmental variations), coinciding with periods of higher resource availability in order to maximize survival.

Population ecology of small rodents and marsupials in a semi-deciduous tropical forest of the southeast Pantanal, Brazil

The Pantanal is a South American biome characterized by extensive plains and stark environmental seasonality. Several habitats are subject to annual flooding, forcing small mammal species to aggregate in dry forest patches, which most likely influences their population dynamics and life history strategies. In order to investigate the seasonal influence on the life history traits of these small mammals, we conducted a 2-year mark-recapture study in the southeastern region of the Brazilian Pantanal (Nhecolândia) and analyzed the population dynamics of the most abundant small mammal species with the jackknife estimator. A trapping effort of 21,560 trap-nights resulted in 615 individuals in 1,171 captures (success = 5.43%). Three species of rodents - Oecomys mamorae (Thomas, 1906), Thrichomys pachyurus (Wagner, 1845), and Clyomys laticeps (Thomas, 1841) - and three species of marsupials - Gracilinanus agilis (Burmeister, 1854), Thylamys macrurus (Olfers, 1818), and Monodelphis domestica (Wagner, 1842) - were obtained. The most abundant species was O. mamorae, followed by G. agilis and T. pachyurus. Oecomys mamorae was more abundant in the wet season and presented an opportunistic reproductive strategy. Gracilianus agilis displayed increased population sizes in the dry season and synchronized, seasonal reproduction during the rainy season. Thrichomys pachyurus had a small population size, delayed response to variations in environmental conditions and higher reproductive rates in the dry season. All species revealed different life history strategies (seasonal, opportunistic or delayed response to environmental variations), coinciding with periods of higher resource availability in order to maximize survival.

Population ecology of small rodents and marsupials in a semi-deciduous tropical forest of the southeast Pantanal, Brazil

The Pantanal is a South American biome characterized by extensive plains and stark environmental seasonality. Several habitats are subject to annual flooding, forcing small mammal species to aggregate in dry forest patches, which most likely influences their population dynamics and life history strategies. In order to investigate the seasonal influence on the life history traits of these small mammals, we conducted a 2-year mark-recapture study in the southeastern region of the Brazilian Pantanal (Nhecolândia) and analyzed the population dynamics of the most abundant small mammal species with the jackknife estimator. A trapping effort of 21,560 trap-nights resulted in 615 individuals in 1,171 captures (success = 5.43%). Three species of rodents - Oecomys mamorae (Thomas, 1906), Thrichomys pachyurus (Wagner, 1845), and Clyomys laticeps (Thomas, 1841) - and three species of marsupials - Gracilinanus agilis (Burmeister, 1854), Thylamys macrurus (Olfers, 1818), and Monodelphis domestica (Wagner, 1842) - were obtained. The most abundant species was O. mamorae, followed by G. agilis and T. pachyurus. Oecomys mamorae was more abundant in the wet season and presented an opportunistic reproductive strategy. Gracilianus agilis displayed increased population sizes in the dry season and synchronized, seasonal reproduction during the rainy season. Thrichomys pachyurus had a small population size, delayed response to variations in environmental conditions and higher reproductive rates in the dry season. All species revealed different life history strategies (seasonal, opportunistic or delayed response to environmental variations), coinciding with periods of higher resource availability in order to maximize survival.