Diversidade de ixodida em roedores e marsupiais capturados no Parque Estadual da Pedra Branca, Rio de Janeiro, Brasil

Didelphis spp. opossums and their parasites in the Americas: A One Health perspective

Medium sized opossums (Didelphis spp.) are among the most fascinating mammals of the Americas, playing important ecological roles (e.g., dispersal of seeds and control of insect populations) in the environment they inhabit. Nevertheless, as synanthropic animals, they are well adapted to human dwellings, occupying shelters within the cities, peripheral areas, and rural settings. These marsupials can harbor numerous pathogens, which may affect people, pets, and livestock. Among those, some protozoa (e.g., Leishmania infantum, Trypanosoma cruzi, Toxoplasma gondii), helminths (e.g., Ancylostoma caninum, Trichinella spiralis, Alaria marcianae, Paragonimus spp.) and arthropods (e.g., ticks, fleas) present substantial public health and veterinary importance, due to their capacity to cause disease in humans, domestic animals, and wildlife. Here, we reviewed the role played by opossums on the spreading of zoonotic parasites, vectors, and vector-borne pathogens, highlighting the risks of pathogens transmission due to the direct and indirect interaction of humans and domestic animals with Didelphis spp. in the Americas.

Ticks, fleas and endosymbionts in the ectoparasite fauna of the black-eared opossum Dipelphis aurita in Brazil

Ticks and fleas are essential vectors of pathogens that affect humans and animals, and among their hosts, synanthropic animals such as the black-eared opossum, Didelphis aurita, play a role in public health due to their ability to move between urban centers and forested areas in Brazil. This study aimed to assess the ectoparasite fauna of D. aurita, as well as the presence of pathogens and endosymbionts in ticks and fleas. Opossums (n = 58) captured in Tomahawk livetraps were examined for ectoparasites, and their blood sampled for further analysis. Additionally, spleen samples were collected in individuals found dead. Samples were PCR screened for Rickettsia spp., Borrelia spp., Anaplasmataceae, and Babesia spp. Two tick species were morphologically identified as Ixodes loricatus 24/58 (41.4%) and Amblyomma sculptum 1/58 (1.7%). For fleas, Ctenocephalides felis was detected in 60.3% (35/58) of the animals, and Xenopsylla cheopis in 5.2% (3/58). PCR analysis detected Anaplasmataceae DNA in 34% (16/47) of pooled samples of C. felis, and in 66.7% (2/3) pooled samples of X. cheopis. Sequence analysis revealed Wolbachia pipientis symbiont in all positive samples. Tick, blood and spleen samples were all negative for the microorganisms assessed. These findings suggest that these arthropods circulate among wildlife and urban environments, which may implicate in their participation in the cycle of zoonotic pathogens among opossums, humans and companion animals.

Ocorrência de ectoparasitas no roedor Oligoryzomys microtis em regiões ao norte do Departamento de La Paz, Bolívia

RESUMO O objetivo deste trabalho foi mapear e descrever a ocorrência de roedores e seus ectoparasitas nas regiões norte do departamento de La Paz, Bolívia. De abril a maio e julho a agosto de 2017, 80 indivíduos da espécie Oligoryzomys microtis foram capturados em armadilhas vivas. Uma amostra aleatória de 36 indivíduos foi analisada quanto à presença de ectoparasitas, encontrando um total de 458 ectoparasitas. Os roedores foram capturados em dois tipos de ambientes: floresta secundária e áreas cultivadas, sendo a área cultivada a área com maior captação de roedores. Dos ectoparasitas, Laelaps sp. foi o gênero com maior abundância e Mysolaelaps sp. o mais prevalente; o gênero Polygenis sp. é aparentemente descrito pela primeira vez na selva amazônica, exigindo estudos adicionais para entender melhor os patógenos que são transmitidos no parasitismo desta pulga em roedores devido à sua importância no ecossistema e para a saúde pública.