title: Role of Indole Production on Virulence of Vibrio cholerae Using Galleria mellonella Larvae Model.
abstract: Cell to cell communication facilitated by chemical signals plays crucial roles in regulating various cellular functions in bacteria. Indole, one such signaling molecule has been demonstrated to control various bacterial phenotypes such as biofilm formation and virulence in diverse bacteria including Vibrio cholerae. The present study explores some key factors involved in indole production and the subsequent pathogenesis of V. cholerae. Indole production was higher at 37 °C than at 30 °C, although the growth at 37 °C was slightly higher. A positive correlation was observed between indole production and biofilm formation in V. cholerae. Maximum indole production was detected at pH 7. There was no significant difference in indole production between clinical and environmental V. cholerae isolates, although indole production in one environmental isolate was significantly different. Both growth and indole production showed relevant changes with differences in salinity. An indole negative mutant strain was constructed using transposon mutagenesis and the direct effect of indole on the virulence of V. cholerae was evaluated using Galleria mellonella larvae model. Comparison to the wild type strain, the mutant significantly reduced the mortality of G. mellonella larvae which regained its virulence after complementation with exogenous indole. A gene involved in indole production and the virulence of V. cholerae was identified.
authors.affiliation: Food Safety and Health Research Unit, Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai, 90110 Thailand.
authors.forename: Taiyeebah
authors.initials: T
authors.lastname: Nuidate
authors.affiliation: Faculty of Medical Technology, Prince of Songkla University, Hat Yai, 90110 Thailand.
authors.forename: Natta
authors.initials: N
authors.lastname: Tansila
authors.affiliation: Department of Food Technology, Faculty of Agroindustry, Prince of Songkla University, Hat Yai, 90110 Thailand.
authors.forename: Suwat
authors.initials: S
authors.lastname: Saengkerdsub
authors.affiliation: Food Safety and Health Research Unit, Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai, 90110 Thailand.
authors.forename: Jetnaphang
authors.initials: J
authors.lastname: Kongreung
authors.affiliation: Food Safety and Health Research Unit, Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai, 90110 Thailand.
authors.forename: Dhamodharan
authors.initials: D
authors.lastname: Bakkiyaraj
authors.affiliation: Food Safety and Health Research Unit, Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai, 90110 Thailand.
authors.forename: Varaporn
authors.initials: V
authors.lastname: Vuddhakul
keywords: Biofilm; Galleria mellonella; Indole; Vibrio cholerae