Molecular Identification of Enteric Viruses in Domestic Animals in Northeastern Gabon, Central Africa

SIMPLE SUMMARY: Enteric viruses cause gastroenteritis in humans and animals, but have also been associated with several extraintestinal diseases. These viruses affect a wide range of vertebrate species, including birds and mammals. Frequent and close contact between humans and animals can potentially lead to the emergence of zoonoses. Approximately 60% of zoonotic diseases in humans are spillovers from wildlife. Preventing future outbreaks of emerging zoonotic diseases calls for better description of the viruses that circulate in domestic animals, because they are located at the human/wildlife interface. We therefore screened for the presence of astroviruses, enteroviruses, and caliciviruses—three of the main viral families causing enteric diseases both in humans and animals—in goats, sheep and dogs living in villages in northeastern Gabon. We identified the presence of astroviruses in goats, a calicivirus in a dog, and enteroviruses in all three species. All detected viruses were animal-related, but not those from wildlife. However, we showed that some human-pathogenic enteroviruses infect goats and dogs. Therefore, further studies are required to better understand the role of domestic animals as amplifiers of reverse zoonotic viruses. ABSTRACT: Astroviruses (AstVs), enteroviruses (EVs), and caliciviruses (CaVs) infect several vertebrate taxa. Transmitted through the fecal–oral route, these enteric viruses are highly resistant and can survive in the environment, thereby increasing their zoonotic potential. Here, we screened for AstVs, EVs, and CaVs to investigate the role of domestic animals in the emergence of zoonoses, because they are situated at the human/wildlife interface, particularly in rural forested areas in Central Africa. Rectal swabs were obtained from 123 goats, 41 sheep, and 76 dogs in 10 villages located in northeastern Gabon. Extracted RNA reverse-transcribed into cDNA was used to detect AstVs, EVs, and CaVs by amplification of the RNA-dependent RNA polymerase (RdRp), or capsid protein (VP1) gene using PCR. A total of 23 samples tested positive, including 17 goats for AstVs, 2 goats, 2 sheep, 1 dog for EVs, and 1 dog for CaVs. Phylogenetic analyses revealed that AstV RdRp sequences clustered with sheep-, goat-, or bovine-related AstVs. In addition, one goat and two sheep VP1 sequences clustered with caprine/ovine-related Evs within the Enterovirus G species, and the CaV was a canine vesivirus. However, human-pathogenic Evs, EV-B80 and EV-C99, were detected in goats and dogs, raising questions on the maintenance of viruses able to infect humans.