Centro de Pequisa em Saúde Animal, Instituto de Pesquisas Veterinárias Desidério Finamor (IPVDF), Estrada do Conde, 6000, Eldorado do Sul, Rio Grande do Sul, Brazil.
Núcleo de Rabilitação de Fauna Silvestre-NURFS, Universidade Federal de Pelotas (UFPEL), Campus Universitário, Capão do Leão, Rio Grande do Sul, Brazil.
Vet Parasitol Reg Stud Reports. 2021 Apr;24:100546. doi: 10.1016/j.vprsr.2021.100546. Epub 2021 Feb 27.
South American opossums of the order Didelphimorphia are considered sentinels for zoonotic infections and environmental diseases, such as for Chagas disease caused by Trypanosoma cruzi. Nevertheless, there is a paucity of data regarding protozoan diseases such Toxoplasma gondii and Neospora caninum in Neotropical marsupials; despite these pathogens have been considered threats to some marsupial species. The aim of this study was to determine whether Didelphis albiventris and Philander frenatus opossums from southern Brazil had been previously exposed to T. cruzi, T. gondii or N. caninum. Opossum samples were obtained by live-trapping of free-ranging animals and collection at wildlife rehabilitation centers in Rio Grande do Sul (RS) state, Brazil. The detection of anti-T. cruzi and anti-T. gondii antibodies was performed by indirect hemagglutination and anti-N. caninum antibodies by competitive enzyme-linked immunosorbent assay. In total, samples were collected from 76 marsupials from nine municipalities in RS state, including 69 D. albiventris (white-eared opossum), and seven were P. frenatus (southern four-eyed opossum). For T. cruzi, 11% were seropositive, and for T. gondii 26% were seropositive. None of the marsupials sampled here were seropositive for N. caninum. Risk factor analysis showed that free-living animals were about five-fold more likely to be infected by T. gondii than were rescued animals. Our study showed the exposure of Neotropical marsupials (D. albiventris and P. frenatus) to protozoan pathogens T. cruzi and T. gondii, while no evidence of N. caninum exposure was found. The set of results presented here may have an effect on ecology and conservation of the studied species and may also indicate possible sentinels of these pathogen circulation.
南美的有袋目动物被认为是人畜共患感染和环境疾病的哨兵，如恰加斯病是由克氏锥虫引起的。然而，关于新热带地区有袋目动物的原生动物疾病，如刚地弓形虫和新生隐球菌，数据很少；尽管这些病原体被认为对一些有袋目物种构成威胁。本研究旨在确定巴西南部的白耳负鼠和短耳负鼠是否曾接触过克氏锥虫、刚地弓形虫或新生隐球菌。通过对自由放养动物的活捕和在巴西南里奥格兰德州（RS）野生动物康复中心的收集获得负鼠样本。通过间接血凝试验检测抗克氏锥虫和抗刚地弓形虫抗体，通过竞争酶联免疫吸附试验检测抗新生隐球菌抗体。总共从 RS 州的九个城市的 76 只有袋动物中采集了样本，包括 69 只白耳负鼠（白耳负鼠）和 7 只南方四眼负鼠（南方四眼负鼠）。对于克氏锥虫，11%呈血清阳性，对于刚地弓形虫，26%呈血清阳性。这里采集的有袋动物没有一种对新生隐球菌呈血清阳性。风险因素分析表明，自由生活的动物感染刚地弓形虫的可能性是获救动物的五倍。我们的研究表明，新热带有袋动物（白耳负鼠和南方四眼负鼠）接触了原生动物病原体克氏锥虫和刚地弓形虫，但没有发现接触新生隐球菌的证据。这里呈现的一系列结果可能对研究物种的生态学和保护产生影响，也可能表明这些病原体循环的可能哨兵。
