Prevalence of Trypanosoma lainsoni and its effects of parasitism on the health of non-volant small mammals from the Brazilian Cerrado.

Small mammals are important hosts and/or reservoirs of Trypanosoma spp. This study aimed to verify the prevalence of Trypanosoma spp. in non-volant small mammals from the Brazilian Cerrado and to test the effects of T. lainsoni on the neutrophil/lymphocyte ratio (N/L) and body condition in rodent and marsupial populations. For this, we collected blood samples of 293 individuals captured in five forest fragments between 2019 and 2020. Blood was used to prepare the blood smears and packed on filter paper for DNA extraction. Generalized linear models were performed to test the effects of T. lainsoni on host health. The DNA was submitted to nested PCR targeting the Trypanosoma spp. 18S rRNA gene. From blood smears analyzed by microscopy, we obtained a positivity rate of 7.2% for Trypanosoma spp. About 31.1% of Gracilinanus agilis, Didelphis albiventris, and Rhipidomys macrurus samples were positive in nested PCR. From the obtained sequences, 83.3% were genetically identical to T. lainsoni and about 11% to T. cruzi TcI. In addition, we reported the infection of T. lainsoni in Hylaeamys megacephalus. We suggest that T. lainsoni does not influence the body condition and N/L ratio for either G. agilis or R. macrurus. Overall, our results expand the host list of T. lainsoni and demonstrate the infection of small mammals by T. cruzi TcI in peri-urban areas.

First report of the intestinal helminth community in the broad-headed spiny-rat Clyomys laticeps (Rodentia, Echimyidae).

The broad-headed spiny rat, Clyomys laticeps, is an echimyid rodent found in open areas of Cerrado and Pantanal biomes in central Brazil and Paraguay. Little is known about the parasites associated with this semi-fossorial species, as no previous studies have been conducted on their helminth fauna. The aim of this study was to report the helminth community structure of C. laticeps inhabiting Serra de Caldas Novas State Park, a Cerrado area in central Brazil. Trappings were carried out in dry grasslands from January to October 2016, and the large and small intestines of 14 C. laticeps individuals were examined for the presence of helminths. Three nematode species were found: Fuellebornema almeidai, Pterygodermatites (Paucipectines) sp., and Subulura forcipata, and 85.7% of the studied species were infected with at least one of these helminths. F. almeidai was the most prevalent species among hosts, and S. forcipata was the most abundant. This study is the first report on helminth community structure in C. laticeps. We report a new host species and increase the known geographical range of F. almeidai, and provide the first record of Pterygodermatites (Paucipectines) sp. infecting echimyids. This is also the first report of S. forcipata in a mammal host.

Non-volant small mammals at an Atlantic forest area situated nearby a limestone quarry (Limeira quarry), state of São Paulo, Brazil / Pequenos mamíferos não-voadores em uma área de Mata Atlântica adjacente à mina de cimento Limeira, São Paulo, Brasil

Our aim was to survey the non-flying small mammals inhabiting an Atlantic forest area situated nearby a limestone quarry (Limeira quarry), located at Ribeirão Grande municipality (SP), southeastern Brazil. Species were captured with pitfall and Sherman traps along eight pairs of 60 m transects distributed at four different distances from the quarry (60, 220, 740 and 1300 m). Between October 2005 and January 2008, 20 small mammal species (11 rodents and nine marsupials) were captured through 4080 pitfall trap-nights and 2040 Sherman trap-nights. The high values of richness, diversity (H' = 2.65) and equability (J = 0.88), and the presence of endemic and threatened species indicates a preserved study site and small mammal assemblage. Marmosops incanus, Monodelphis americana and Oligoryzomys nigripes were the commonest species at the study site. Trapping sites located closer to the quarry (60 and 220 m away from the quarry) presented lower richness and were dominated by disturbance-tolerant species, such as O. nigripes, that usually benefit from habitat alterations. On the other hand, sites located away from the quarry and closer to Serra do Mar Protected Area (740 and 1300 m away from the quarry) presented higher richness and diversity, and a higher abundance of disturbance-intolerant species. These results suggest a negative distance-dependent impact of quarrying on small mammal communities. In this way, our results point out to the importance of long-term monitoring of quarrying impacts on small non-flying mammal communities and populations, and the need of conservation strategies in order to ensure species persistence in these areas.

O objetivo desse estudo foi elaborar uma lista das espécies de pequenos mamíferos não-voadores que ocorrem em uma região de Mata Atlântica localizada nas proximidades de uma área de mineração de calcário (Mina Limeira), situada no município de Ribeirão Grande (SP), sudeste do Brasil. Para tal, foram montadas estações de captura contendo linhas de balde e armadilhas do tipo Sherman em oito transectos de 60 m, agrupados em pares e localizados a diferentes distâncias da cava da mina (60, 220, 740 e 1300 m de distância), partindo da área antropizada em direção à área de proteção ambiental da Serra do Mar. Entre outubro de 2005 e janeiro de 2008, com um esforço de 4080 baldes-noite e 2040 armadilhas-noite, foram capturadas 20 espécies de pequenos mamíferos, sendo 11 roedores e nove marsupiais. A alta riqueza, diversidade (H' = 2,65) e equabilidade (J = 0,88) estimada na área de estudo, além da presença de espécies endêmicas e ameaçadas, indicam o grau de preservação da área de estudo e da assembléia de pequenos mamíferos. As espécies mais comuns foram Marmosops incanus, Monodelphis americana e Oligoryzomys nigripes. Os transectos localizados mais próximos da cava (60 e 220 m de distância) foram dominados por espécies indicadoras de habitats alterados, como O. nigripes, que tende a proliferar nessas situações. Por outro lado, os sítios mais distantes (740 e 1300 m de distância da cava) apresentaram maior riqueza e diversidade, e espécies mais sensíveis a perturbações. Esses resultados sugerem um possível impacto negativo dependente de distância em relação à mina de calcário. Dessa maneira, nossos resultados apontam para a importância de monitoramentos de longo prazo sobre os impactos da mineração sobre as populações e a comunidade de pequenos mamíferos não-voadores, além da elaboração de planos de conservação para assegurar a persistência das espécies na região.