A cross-sectional survey of snake oral bacterial flora from Hong Kong, SAR, China

To determine the pattern of oral bacterial flora and their sensitivity to antibiotics in freshly captured native snakes in Hong Kong SAR, People's Republic of China.

Healthy native snakes were captured and kept in a designated centre. Snake species were identified by experienced herpetologists. Mouth swabs were taken by the veterinarian using strict aseptic techniques. The snakes were released back to the wild immediately after the above procedure. Swabs were sent for microbiological studies of bacterial culture and antibiotic sensitivity.

47 venomous snakes of the families Colubridae, Elapidae and Viperidae and 53 non-medically important snakes were captured. 406 bacterial isolates of 72 different species were cultured: these included gram negative and positive bacterial species and also anaerobic bacterial species. With the exception of the white-lipped pit viper (Cryptelytrops albolabris), venomous snakes harboured more pathogenic bacteria and total bacteria species compared to the non-medically important species. Of the venomous snakes, the Chinese cobra (Naja atra) harboured the largest number of bacterial species. In the present study, all gram negative bacteria associated with wound infection were sensitive to levofloxacin, netilmicin and piperacillin/tazobactam. Many gram negative bacteria in the study were not sensitive to cefuroxime axetil. Amoxicillin/clavulanic acid was an appropriate choice to cover Enterococcus faecalis and anaerobes.

In the presence of wound infection from snakebite injury in Hong Kong, first line empirical antibiotics include amoxicillin/clavulanic acid plus levofloxacin. Prophylactic antibiotics may be considered in selected cases of Chinese cobra (N. atra) bite, otherwise prophylactic antibiotics are not recommended in snakebite unless tissue necrosis is present.