First characterization of the oral microbiota of capybaras (Hydrochoerus hydrochaeris) in Brazil: insights into one health risks.

Capybara (Hydrochoerus hydrochaeris), the largest rodent in the world, are animals native to Brazil that are increasingly adapting to urban environments, which raises concerns for One Health, including the risk of zoonotic diseases such as Brazilian Spotted Fever. Moreover, increased interaction between humans and capybaras can lead to accidents involving injuries and infections. This study aimed to characterize the oral microbiota of healthy capybaras in a peri-urban environment in Goiás state, midwestern region of Brazil. Oral clinical examinations were performed, and subgingival biofilm samples were collected from eight capybaras captured on the campus of the Universidade Federal de Goiás. Sequencing of the V4 region of the 16 S ribosomal RNA gene revealed a predominance of the phyla Firmicutes (48.06%), Proteobacteria (22.07%), Actinobacteriota (11.56%), and Bacteroidota (7.14%). The most abundant genera were Streptococcus (36.68%), Rothia (6.47%), and Weissella (2.02%). Microbial composition varied among individuals, with notably lower diversity in the only juvenile evaluated. This interindividual variability may be influenced by dietary and environmental factors. Genera frequently associated with periodontal disease, such as Fusobacterium and Bacteroides, were detected at low prevalence. The presence of Streptococcus, Rothia, and Klebsiella suggests the pathogenic potential of these microorganisms for humans and animals, especially in the event of accidents. This study is the first to evaluate the oral microbiota of capybaras and opens an important field of research within the One Health framework. These findings reinforce the importance of microbiological monitoring of synanthropic wildlife for both public health and the oral health of the species.