Parasites of Didelphis aurita opossums captured in urban environments from Southeastern Brazil

• Ano de defesa: 2019
• Autor(a) principal: Santos, Marcos Antônio Bezerra
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa
• Palavras-chave em Português: Didelphidae; Carrapatos; Pulgas; Helminto; Protozoário; Parasitologia veterinária; Ciências Biológicas
• Link de acesso: https://locus.ufv.br//handle/123456789/28554

Didelphis spp. are marsupials well adapted to anthropogenic activity, playing important role in the dissemination of pathogens to humans and domestic animals due to their circulation between the wild and the urban environment. Several parasite species, consisting of vectors of zoonotic pathogens (i.e. ticks and fleas), helminths and protozoa affect these marsupials. The aim of this study was to evaluate the parasitic fauna of D. aurita, and identify arthropod borne pathogens transmitted by ticks and fleas. From January to June 2019, 58 D. aurita were captured and ectoparasites, blood, spleen and fecal samples were collected for molecular and parasitological tests. DNA of ticks, blood and spleen samples was extracted and screened for Rickettsia, Borrelia, Babesia spp. and Anaplasmataceae by conventional Polymerase Chain Reaction (PCR). Blood and spleen DNA samples of 57 animals were further screened for Toxoplasma gondii by real time PCR (qPCR). Two tick species were identified, Ixodes loricatus in 41.38% (24/58) and Amblyomma sculptum in 1.72% (1/58) of the animals. For fleas, Ctenocephalides felis felis was detected in 60.34% (35/58) of the animals, and Xenopsyla cheopis in 5.17% (3/58). PCR analysis detected Anaplasmataceae DNA in 34.04% (n = 16/47) pool samples of C. felis felis, and in 66.66% (n = 2/3) pool samples of X. cheopis. Sequence analysis of the products revealed Wolbachia pipientis symbiont in all positive samples. Tick, blood and spleen samples scored negative for other pathogens assessed by conventional PCR. T. gondii DNA was detected in 26.32% (15/57) of the animals and BLAST analysis demonstrated 100% homology with sequences available in the GenBank database. Fecal samples were evaluated by parasitological procedures. Eggs and oocysts were analyzed at different magnifications (400x and 1000x), and their identification, together with adult nematodes, was established on morphological and morphometric features. Of all samples analyzed, 87.76% (n = 43/49) scored positive for at least one gastrointestinal parasite, being 83.67% (41/49) for helminths, and 65.30% (32/49) for protozoa. For Cryptosporidium, only 13 samples were evaluated due to insufficient amount of feces obtained of some animals. A frequency of 23.08% (3/13) was reported for this parasite. Samples positive for Eimeria spp. oocysts were allowed to sporulate in 2.5% potassium dichromate (K 2 Cr 2 O 7 ), and detailed morphometric analyses were performed to determine the species present. Opossums were infected with from one to five Eimeria spp. Four of the eimerians were discovered, described and named by others: E. auritanensis, E. caluromydis, E. gambai, and E. philanderi. Additionally, sporulated oocysts of a species new to science, herein named as Eimeria vicoensis n. sp., were detected. Data herein obtained demonstrated the parasitism in D. aurita by some species of ectoparasites, including those commonly found in domestic animals (C. felis felis and A. sculptum), and high infection rates by several helminths and protozoa species, including those with zoonotic potential. These findings imply that these opossums may be involved in zoonotic cycles of these parasites in urban environments; however, further studies are needed to elucidate the extent to which these animals are involved in the dissemination of these pathogens. Keywords: Didelphidae. Ticks. Fleas. Helminths. Protozoa.