The Presence of Four Pathogenic Oral Bacterial Species in Six Wild Snake Species from Southern Taiwan: Associated Factors

Abstract

The oral cavity of snakes serves as a habitat for various microorganisms, some of which may include potential zoonotic pathogens posing risks to hosts and causing wound infections in snakebite victims. Clinical studies on snakebite cases in Taiwan have identified specific pathogens, such as Enterococcus faecalis (Gram-positive), Morganella morganii, Aeromonas hydrophila, and Pseudomonas aeruginosa (Gram-negative). However, the prevalence of these bacteria in the oral cavity of wild snakes remains largely unknown. This study investigated the occurrence of these bacteria in six wild snake species (Naja atra, Bungarus multicinctus, Trimeresurus stejnegeri, Protobothrops mucrosquamatus, Boiga kraepelini, and Elaphe taeniura friesi) from southern Taiwan, along with factors influencing their presence. Oropharyngeal swab samples were collected from a substantial number of wild-caught snakes (n = 1104), followed by DNA extraction, polymerase chain reaction, and gel electrophoresis. The band positions of samples were compared with positive and negative controls to determine the presence of target bacteria in each sample. The overall occurrence rates were 67.4% for E. faecalis, 31.5% for M. morganii, 8.2% for A. hydrophila, and 7.7% for P. aeruginosa. Among snake species, B. kraepelini exhibited dominance in E. faecalis (93.4%), A. hydrophila (17.1%), and P. aeruginosa (14.5%), while male N. atra showed dominance in M. morganii (51.3%). The occurrence of E. faecalis was lowest in winter. The results of multiple logistic regression analyses suggest that factors such as species, sex, temperature, season, and coexisting pathogens may have a significant impact on the occurrence of target bacteria. These findings have implications for wildlife medicine and snakebite management.

Isolation and Identification of Morganella morganii from Rhesus Monkey (Macaca mulatta) in China

“…In recent years, there have been many reports on the co-infection of humans and animals with M. morganii. For example, M. morganii exists in the oral cavity of snakes and can cause human infection if animals bite or scratch humans [4,5]; Park et al [6] demonstrated that M. morganii strains isolated from captive dolphins pose a risk of fatal zoonotic infection and fail antibiotic treatment due to prolonged resistance; M. morganii is one of the main histamine-producing bacteria, and eating fresh fish and dairy products contaminated with M. morganii can cause food-borne histamine poisoning [7,8]. M. morganii infection can cause cellulitis, endocarditis, osteomyelitis, septic arthritis, diarrhea, and other diseases in humans and animals and even lead to potentially fatal systemic infection [8][9][10].…”