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| Author(s): |
Marcela Figuerêdo Duarte Moraes
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Jaboticabal. 2020-07-27. |
| Institution: | Universidade Estadual Paulista (Unesp). Faculdade de Ciências Agrárias e Veterinárias. Jaboticabal |
| Defense date: | 2020-06-23 |
| Advisor: | Estevam Guilherme Lux Hoppe |
| Abstract | |
Generalist carnivores are undemanding and have varied eating habits, and, due to this opportunistic behavior, these animals are close to human populations, becoming vulnerable to domestic animal pathogens, but also being able to carry pathogens to domestic animals and man. In the Iguaçu National Park (PARNA Iguaçu), ring-tailed coatis and crab-eating foxes are common species of generalist and opportunistic carnivores with a wide distribution in the park's territory. Recently, by traditional parasitological methods, the presence of some filarids nematodes with zoonotic potential was diagnosed in wild carnivores from PARNA Iguaçu. Also, autochthonous cases of Canine Visceral Leishmaniasis have been confirmed in domestic dogs and humans in the region. Thus, due to the importance for the current public health, this research aims to study filariasis and visceral leishmaniasis in generalist carnivores from PARNA Iguaçu, as well as to understand the parasite-host relationship and the ecological processes that may favor transmission of these agents among wild populations, domestic dog and humans. For this, 284 wild mammals were captured using Tomahawk and Sherman traps. The animals were chemically contained for jugular puncture and collection of blood samples for parasitological, serological, and molecular diagnosis of filarids and trypanosomatids. Sixty-four rural properties were visited around PARNA, and 226 samples were collected from domestic dogs. Necropsy of 20 wild carnivores run over in the BR 469 road (inside PARNA) was performed, aiming at the same analyzes. The modified Knott test performed the initial filariid diagnosis, subsequently followed by the DNA extraction from blood and tissue samples, through by the chloroform-isoamyl alcohol technique. For molecular screening of filarids, the PCR reactions were performed with 5S rDNA region amplification, afterward new PCR reactions were performed with the filariid positive samples, with amplification of Myosin and hsp70 genes, aiming at species identification. Regarding the molecular research of Trypanosomatidae, PCR was first performed with primers from the mitochondrial Cytochrome B gene. New PCR was performed with the positive samples with amplification of the 18S rDNA region of trypanosomatids. All PCR positive samples were subjected to sequencing PCR with the BigDye kit, in an ABI3130 sequencer. The electropherograms were analyzed, and the sequences aligned with the NCBI bank sequences. From these, phylogenetic trees were generated for each gene studied in each group of parasites. Leishmania infantum IIFT was performed for all dogs sampled. As a result, it was possible to observe the presence of five species of filaridae parasitizing ring-tailed coatis (Nasua nasua) in PARNA Iguaçu: Mansonella sp1, Mansonela sp. 2, two new genera identified here as Embainhada 1 and 2, and Dirofilaria immitis. For domestic dogs, only Acanthocheilonema sp. was diagnosed. These data are unprecedented for the region under study, since the knowledge about filaridae of wild animals from the Neotropical region is limited. It is important to note that ring-tailed coatis showed a high prevalence of filarids infection (74.5%), and can act as good reservoirs for these nematodes in the studied region. Some of the identified genera are described as zoonotic parasites in other regions of Brazil and the world, warning to the need for health surveillance, once these parasites may also have zoonotic potential in this area. Regarding trypanosomatids, only L. infantum was detected in domestic dogs from Foz do Iguaçu city, although positive dogs were identified in the IIFT for L. infantum (28.7%) in some rural properties surrounding the PARNA. Trypanosoma cruzi was also identified in a ring-tailed coati from Iguazu Falls tourist area and was typified as T. cruzi DTU’s TcIV. We can suggest that domestic dogs are the important visceral leishmaniasis reservoirs in Foz do Iguaçu, PR, requiring vigilance and actions to control vectors and domestic reservoirs aiming to prevent the parasite in wild mammals from PARNA Iguaçu because them can be amplified (spillback) in the many susceptible host species that inhabit the Atlantic forest of PARNA Iguaçu. The presence of T. cruzi in ring-tailed coatis is an alert, these animals act as good sentinels of the wild environment, and in this way, demonstrating that T. cruzi is circulating in the forest area. The data obtained in this research indicate the occurrence and circulation, in PARNA Iguaçu, of vector-borne parasites that are of great importance for public health worldwide. Furthermore, it is possible to suggest that domestic dogs are responsible for maintaining the circulation of L. infantum, while coatis are excellent reservoirs for filarid nematodes and can also act as reservoirs for T. cruzi in the PARNA Iguaçu region, as already reported for other Brazilian biomes, being an important sentinel animal to be monitored by health surveillance agencies in the studied region. (AU) | |
| FAPESP's process: | 16/14886-9 - Wild generalists carnivores as sentinels for Filariasis and Visceral Leishmaniase in Iguaçu National Park |
| Grantee: | Marcela Figuerêdo Duarte Moraes |
| Support Opportunities: | Scholarships in Brazil - Doctorate |