Diversity and antibiotic resistance profiles of bacteria isolated from the oral cavity of captive snakes

• Captive Viperidae snakes harbor diverse oral bacteria with significant antibiotic resistance. • M. morganii and P. rettgeri dominate oral microbiota of four venomous snake species. • ESBL-producing bacteria identified in snake oral cavities raise clinical concerns. • Porthidium lansbergii showed highest bacterial diversity among studied snake species. Venomous snake bites are a global public health issue, causing between 81 000 and 138 000 annual deaths and 400 000 permanent disabilities. This study investigated the oral bacterial diversity and antibiotic resistance profiles in captive Viperidae snakes. Oral swabs from 48 specimens across four species ( Porthidium lansbergii , Bothriechis nigroviridis , Cerrophidion sasai , and Bothrops asper ) were analyzed using culture-dependent methods. Bacterial isolation and identification using the VITEK 2 automated system revealed 41 strains from 12 genera, predominantly Gram-negative bacteria, including Morganella morganii (11 isolates) and Providencia rettgeri (10 isolates). Antibiotic susceptibility testing demonstrated significant resistance patterns, with 100% resistance to cephalothin and cefazolin in M. morganii , and emerging extended-spectrum β-lactamase (ESBL) production in Enterobacter cloacae and Sphingomonas paucimobilis . The comparative analysis showed that P. lansbergii exhibited the highest bacterial diversity. These findings highlight the complex oral microbiota of venomous snakes and underscore the need for evidence-based antibiotic strategies in snakebite management, particularly given the global rise in antimicrobial resistance. Las mordeduras de serpientes venenosas son un problema de salud pública mundial, causando entre 81,000 y 138,000 muertes anuales y 400,000 discapacidades permanentes. Este estudio investigó la diversidad bacteriana oral y los perfiles de resistencia antibiótica en serpientes Viperidae mantenidas en cautiverio. Se analizaron hisopados orales de 48 especímenes de cuatro especies ( Porthidium lansbergii , Bothriechis nigroviridis , Cerrophidion sasai y Bothrops asper ) mediante métodos dependientes de cultivo. La identificación bacteriana mediante el sistema automatizado VITEK 2 reveló 41 cepas de 12 géneros, predominantemente bacterias Gram-negativas, incluyendo Morganella morganii (11 aislamientos) y Providencia rettgeri (10 aislamientos). Las pruebas de susceptibilidad antibiótica demostraron patrones de resistencia significativos, con 100% de resistencia a cefalotina y cefazolina en M. morganii , y producción emergente de β-lactamasas de espectro extendido (BLEE) en Enterobacter cloacae y Sphingomonas paucimobilis . El análisis comparativo mostró que P. lansbergii exhibió la mayor diversidad bacteriana. Estos hallazgos resaltan la complejidad del microbiota oral en serpientes venenosas y subrayan la necesidad de estrategias antibióticas basadas en evidencia para el manejo de mordeduras, particularmente ante el aumento global de la resistencia antimicrobiana.