Bacterial community analysis identifies K. pneumoniae as a native symbiotic bacterium in the newborn Protobothrops mucrosquamatus

<strong>Background</strong>: The study of the native microbiome of organisms is crucial. The connection between the native microbiome and the host affects the formation of the innate immune system and the organism’s growth. However, the native microbiome of newborn venomous snakes has not been reported. Therefore, our study aimed to determine the oral and skin microbiomes of newborn <em>Protobothrops mucrosquamatus</em> (<em>P. mucrosquamatus</em>)<em>.</em> <strong>Results:</strong> In terms of the oral and skin microbiome, the main species were <em>Klebsiella pneumoniae </em>(<em>K. pneumoniae</em>) linkages. According to subspecies/species analysis, the proportion from high to low was <em>K. quasipneumoniae</em> subsp. Similipneumoniae, <em>K. pneumoniae</em> subsp. Pneumoniae, and <em>K. pneumoniae</em> subsp. Rhinoscleromatis. These three bacteria accounted for 62.5% and 85% of skin and oral activity, respectively. The oral microbiome of newborn<em> P. mucrosquamatus</em> did not investigate the common bacteria found in snakebite wounds or oral cultures in adult snakes. Therefore, the source of other microbiomes in the oral cavities of adult snakes may be the habitat environment or prey. Functional Annotation of the Prokaryotic Taxa (FAPROTAX) analysis showed that microbiome metabolism was related to human infection and intestinal bacteria owing to the dominance of <em>K. pneumoniae</em> linkages. Fermentation was predicted in this study. The characteristics of <em>K. pneumoniae </em>may impact the development of venom in venomous snakes. <strong>Conclusion:</strong> The results of the native microbiome in the oral cavity and skin of newborn <em>P. mucrosquamatus</em> demonstrated that the habitat environment and prey capture would affect the composition of bacteria in adult snakes. This explains why soil-associated bacteria and Enterobacter were dominant in the oral and skin microbiomes of adult snakes. We hypothesised that the native microbiome influences newborn venomous snakes and that <em>K. pneumoniae</em> linkages related to citrate fermentation may play a role in venom growth. However, further verification of this is required.