Identificação morfológica e molecular de helmintos recuperados de pequenos mamíferos e moluscos e estudo das lesões nos roedores infectados: ênfase em dois parques urbanos de Belo Horizonte

Abstract

Small mammals in general are extremely adaptable and are widely distributed worldwide. These animals can be definitive hosts or intermediate hosts of numerous species of helminth parasites such as trematodes, cestodes and nematodes. Some of these species may have zoonotic potential and, the sharing these parasites with humans and their domestic animals, can cause diseases often associated with morbidity. In addition, terrestrial molluscs also inhabit urban parks and can act as intermediate hosts of different helminth species that have small mammals as definitive hosts, and some of these species may have zoonotic potential. In the present study, small mammals were captured in the Parque Municipal das Mangabeiras and Parque Municipal Jacques Cousteau located in the municipality of Belo Horizonte, Minas Gerais, Brazil, from April 2018 to March 2019. After capture, the animals were sedated to collect intravenous blood, followed by euthanasia of the rodents, necropsy and individualization of the organs to recover helminths. Two species of wild rodents were captured: Cerradomys subflavus (n = 38) and Necromys lasiurus (n = 39), the exotic Rattus rattus species (n = 39), two opossum species: Didelphis albiventris (n = 12) e Didelphis aurita (n = 6) and one cuica species Marmosops incanus (n = 5). From different specimens of small mammals, adult specimens of Litomosoides sigmodontis (abdominal cavity), the species Calodium hepaticum (sin. Capillaria hepatica) and strobilocerco of Hydatigera taeniaeformis (liver), Angiostrongylus cantonensis (pulmonary arteries), the species Physaloptera bispicuta, (stomach), the species Nippostrongylus brasiliensis, Guerrerostrongylus gomesae and Hymenolepis diminuta (small intestine) and the genera Trichuris and Syphacia (large intestine) were recovered. From an opossum (D. albiventris) the species Rhopalias coronatus parasitizing the small intestine and the species Aspidodera raillieti and Cruzia tentaculata parasitizing the large intestine were recovered. Three species with zoonotic potential were identified in the Jacques Cousteau Municipal Park, Calodium hepaticum (sin. Capillaria hepatica), Hydatigera taeniaeformis and Hymenolepis diminuta, and the species Hymenolepis diminuta in the Mangabeiras Municipal Park. During the capture of small mammals, snails found on the trails were also collected. From a specimen of Achatina fulica, third metastrongylid larvae stage were recovered, and used to infect an experimental model to recovery adult helminths for molecular and phylogenetic analysis. The results confirm that the species of Angiostrongylus recovered from the pulmonary arteries of R. rattus and the specimen of A. fulica from Parque Jacques Cousteau belong to the same species, Angiostrongylus cantonensis. BALB / c mice (Mus musculus) and Wistar rats (Rattus norvegicus) were used for experimental infection of Angiostrongylus cantonensis, for histopathological evaluation of the lesions caused by the species. The results demonstrate the importance of research carried out in forest fragments within urban centers and of monitoring the animals that inhabit these places, due to the ability of these species to host agents with zoonotic potential, increasing the risk of disease transmission to the human population. Special attention should be given to synanthropic species and domestic animals due to the greater proximity of these animals to the population surrounding these parks.