A preliminary research on regulation of motility, biofilm formation andoxidative stress capacity of Vibrio cholera by CcmC

OBJECTIVE To explore the phenotypic characteristics of Vibrio cholerae (VC) with deficiency of ccmC (ΔccmC) such as growth, motility, chemotaxis, biofilms and oxidative stress. METHODS The relevant phenotypic characteristics were observed and compared among the Vibrio cholerae wild strain (WT), ΔccmC and ΔccmC recovery strain (ΔccmC::ccmC) through the experiments such as plate dynamics, chemotaxis, biological membrane crystal violet staining and hydrogen peroxide tolerance. RESULTS The growth experiment confirmed that there was no significant difference in the growth between the WT group and the ΔccmC group, while the diameter of the dynamic loop of the ΔccmC group was remarkably shorter than that of the WT group(q=4.109,P＜0.001),the chemotaxis ability of the ΔccmC group was remarkably lower than that of the WT group (q=5.307,P＜0.001). The biofilm formation experiment demonstrated that the biofilm formation capacity weakened more remarkably in the ΔccmC group than in the WT group (q=14.610,P＜0.001); the hydrogen peroxide tolerance test confirmed that the growth of ΔccmC group was remarkably slower than that of the WT group(t=2.215,P=0.035);the hydrogen peroxide antibacterial experiment indicated that the diameters of antibacterial zones of ΔccmC group were significantly greater than those of the WT group (q=3.003,P=0.013). As compared with the ΔccmC group, most of the above detection indicators of the ΔccmC::ccmC group could be restored. CONCLUSIONS It is for the first time in the study to confirmed that ccmC can regulate the motility, biofilm formation and oxidative stress phenotypes of V. cholerae.