Investigation of possible molecular mechanisms underlying the regulation of adhesion in Vibrio alginolyticus with comparative transcriptome analysis

Adhesion capability to fish mucus, which can be affected by environmental conditions, is considered to be a key virulence factor of Vibrio alginolyticus although the molecular mechanism is still unclear. In the present study, V. alginolyticus was treated with stress conditions including Cu2+ (50 mg/L), Pb2+ (100 mg/L), Hg2+ (50 mg/L) and low pH (pH 5). We found these stress treatments were capable of reducing the adhesion of V. alginolyticus, while the expression levels of multiple genes were significantly changed according to the results of high throughput sequencing. The expression of randomly selected genes was confirmed by QPCR, which reinforced the reliability of the sequencing data. Ontology assignments and KEGG pathway analysis indicated that stress treatments affect pathways that may be related to adhesion. Our results identified genes which might play a key role in the adhesion process of V. alginolyticus, which could lay a foundation for further functional analysis of these genes in the process of adhesion. As these genes were sensitive to environmental factors, this may explain why the adhesion process can be influenced by environmental factors.