RESUMO
Wild felids are vital to maintaining the ecological balance in natural environments as they regulate prey populations at different levels of the food chain. Changes in the dynamics of predator populations can impact the entire biodiversity of an ecosystem. There are few reports of Adenovirus infections in these animals, and little is known about their epidemiology. Therefore, a deeper understanding of these viruses within a One Health framework is essential, given their importance to animal, human, and environmental health. This study aimed to detect Adenovirus DNA in fecal samples of wild felids from a remnant of the Atlantic Forest in southeastern Brazil, renowned for its high biodiversity. A total of 43 fecal samples, 11 from jaguar (Panthera onca) and 32 from ocelot (Leopardus pardalis), were collected. The samples were subjected to viral nucleic acid extraction and genetic material amplification through PCR, followed by nucleotide sequencing. All phylogenetic analyses were based on the amino acid sequences of the DNA polymerase and IV2a genes. Adenovirus DNA was detected in the feces of both species, with two samples of each feline testing positive. This study reports, for the first time, the occurrence of Adenovirus associated with feces of Panthera onca and Leopardus pardalis. All detected sequences were grouped within the Mastadenovirus genus. Based solely on phylogenetic distance criteria, the identified sequences could be classified as Mastadenovirus bosprimum and Mastadenovirus from the vampire bat Desmodus rotundus. We hypothesize that Adenoviruses were associated with the prey consumed, which may allow the felines to act as eventual viral dispersing agents in the environment, in addition to the risk of being infected. This study provides new information on the association of Adenoviruses with wild felids and their prey, and offers important insights into the ecological dynamics of these viruses in natural environments. It suggests that wild felines may play a crucial role in viral surveillance programs.
RESUMO
The present study reports on patterns of parasitism by Amblyomma humerale on yellow-footed tortoise, Chelonoidis denticulatus, in the Atlantic Forest of southeastern Brazil. The tortoises were sampled occasionally, from July 2005 to January 2020. We collected 81 adult ticks from seven tortoises (mean = 11.57 ± 6.90 ticks/host), of which 72 were males (88.9%) and nine females (11.1%), resulting in an 8:1 sex ratio (males:females). Males were found in clusters, attached to the carapace. Females occurred mainly isolated, attached to coriaceous integumental areas (n = 7; 77.8%), especially the engorged females (100%). We suggest that the difference between attachment sites is a strategy used by fertilized females to avoid mechanical removal from their host through friction with elements of the environment. Because they undergo a considerable increase of volume when engorged, they move to more sheltered places on their host's surface. The parasitism patterns by A. humerale on C. denticulatus were compatible with those observed in the Amazon region and in the Cerrado-Amazonia transition. The present work provides information about the life history and host-parasite interface of the two species and contributes to understanding the parasitism patterns by A. humerale on C. denticulatus in the Atlantic Forest of southeastern Brazil.
Assuntos
Ixodidae , Tartarugas , Amblyomma , Animais , Brasil , Feminino , Florestas , MasculinoRESUMO
Abstract The present study reports on patterns of parasitism by Amblyomma humerale on yellow-footed tortoise, Chelonoidis denticulatus, in the Atlantic Forest of southeastern Brazil. The tortoises were sampled occasionally, from July 2005 to January 2020. We collected 81 adult ticks from seven tortoises (mean = 11.57 ± 6.90 ticks/host), of which 72 were males (88.9%) and nine females (11.1%), resulting in an 8:1 sex ratio (males:females). Males were found in clusters, attached to the carapace. Females occurred mainly isolated, attached to coriaceous integumental areas (n = 7; 77.8%), especially the engorged females (100%). We suggest that the difference between attachment sites is a strategy used by fertilized females to avoid mechanical removal from their host through friction with elements of the environment. Because they undergo a considerable increase of volume when engorged, they move to more sheltered places on their host's surface. The parasitism patterns by A. humerale on C. denticulatus were compatible with those observed in the Amazon region and in the Cerrado-Amazonia transition. The present work provides information about the life history and host-parasite interface of the two species and contributes to understanding the parasitism patterns by A. humerale on C. denticulatus in the Atlantic Forest of southeastern Brazil.
Resumo O presente estudo relata os padrões de parasitismo de Amblyomma humerale em jabuti-tinga, Chelonoidis denticulatus, na Mata Atlântica do Sudeste do Brasil. Os jabutis foram amostrados de forma ocasional, entre julho de 2005 e janeiro de 2020. Foram amostrados sete jabutis e coletados 81 carrapatos adultos (media = 11,57 ± 6,90 carrapatos/hospedeiro), sendo 72 machos (88,9%) e nove fêmeas (11,1%), resultando em uma razão sexual de 8:1 (machos:fêmeas). Os machos encontravam-se agrupados e aderidos à carapaça. As fêmeas ocorreram principalmente isoladas e fixadas a áreas de tegumento coriáceo (n = 7; 77,8%), especialmente as fêmeas ingurgitadas (100%). Sugere-se que a diferença entre os locais de fixação seja uma estratégia das fêmeas fecundadas, para evitar a remoção mecânica por atrito com o ambiente, uma vez que aumentam consideravelmente seu volume quando ingurgitadas, deslocando-se para locais mais abrigados na superfície do hospedeiro. Os padrões de parasitismo de C. denticulatus por A. humerale foram compatíveis com aqueles observados na Amazônia e na transição Amazônia-Cerrado. O presente trabalho contribui com informações acerca da história de vida e da relação parasito-hospedeiro entre as duas espécies, contribuindo para o entendimento dos padrões de parasitismo de A. humerale em C. denticulatus na Mata Atlântica do sudeste do Brasil.