Transcriptomic Analysis of Laribacter hongkongensis Reveals Adaptive Response Coupled with Temperature

Bacterial adaptation to different hosts requires transcriptomic alteration in response to the environmental conditions. Laribacter hongkongensis is a gram-negative, facultative anaerobic, urease-positive bacillus caused infections in liver cirrhosis patients and community-acquired gastroenteritis. It was also found in intestine from commonly consumed freshwater fishes and drinking water reservoirs. Since L . hongkongensis could survive as either fish or human pathogens, their survival mechanisms in two different habitats should be temperature-regulated and highly complex. Therefore, we performed transcriptomic analysis of L . hongkongensis at body temperatures of fish and human in order to elucidate the versatile adaptation mechanisms coupled with the temperatures. We identified numerous novel temperature-induced pathways involved in host pathogenesis, in addition to the shift of metabolic equilibriums and overexpression of stress-related proteins. Moreover, these pathways form a network that can be activated at a particular temperature, and change the physiology of the bacteria to adapt to the environments. In summary, the dynamic of transcriptomes in L . hongkongensis provides versatile strategies for the bacterial survival at different habitats and this alteration prepares the bacterium for the challenge of host immunity.