The study, published in Conservation Biology, examined the exchange of digestive-track bacteria between humans, mountain gorillas and domesticated animals living in overlapping habitats.

The findings indicated the presence of identical, clinically resistant bacteria, in gorillas, implying that antibiotic-resistant bacteria or resistance-conferring genetic elements transfer from humans to gorillas, the researchers said. Gorilla populations subject to research and tourism are particularly vulnerable, they noted.

Mountain gorillas were at a higher risk of a bacteria exchange whether antibiotic consumptions were managed well or carelessly, researchers said, indicating preventing direct contact between people and the gorillas may not be enough to eliminate the possibility of an exchange.

In the article, researchers encouraged hand-washing before and after entering forests, discouraged human defecation in the forest and recommended mandatory wearing of aerosol-limiting face masks for people entering ape habitats.