Involvement of Hfq in stress response and transcriptional regulation of virulence genes and stress-responsive genes in Vibrio cholera / 中华微生物学和免疫学杂志

ABSTRACT

Objective To characterize Hfq-dependent phenotypes in stress response and to dissect Hfq-dependent transcription of virulence genes and stress-responsive genes in Vibrio cholera.Methods The hfq null mutant strain (△hfq) and the complemented mutant strain (△hfq/pUC18-hfq) were constructed from the wild-type Vibrio cholera.Comparisons on the motility,biofilm formation,growth under various oxygen-supplying conditions,outer membrane resistance,and sensitivity to oxidative stress were analyzed between the wild type strain and the mutant strains.Reverse-transcript fluorescence quantitative PCR (RT-qPCR) was used to determine the transcriptional levels of target genes in the above mentioned strains.Results △hfq and △hfq/pUC18-hfq strains were successfully constructed.The motility,outer membrane resistance and sensitivity to oxidative stress were reduced,but biofilm formation was enhanced in the hfq null mutant strain.RT-qPCR testified that Hfq had regulation effects on gene transcription for forming falagellum,extracellular polysaccharide,outer membrane protein and oxidative stress in Vibrio cholera.Conclusion As a RNA chaperone,Hfq could affect Vibrio cholera in its biofilm formation,resistance to oxidative stress and antibiotics resistance through regulating the transcription of multiple metabolic genes and virulence genes,which indicates that Hfq,combined with other regulators,may play a key role in the complex regulation of metabolic genes and virulence genes.