Role of a TehA homolog inVibrio choleraeC6706 antibiotic resistance and intestinal colonization

Abstract

Vibrio cholerae is the causative agent of the devastating diarrheal disease cholera. A number of regulatory pathways are involved in V. cholerae pathogenesis and antibiotic resistance. For example, there are over 40 LysR-family proteins in the V. cholerae genome, but most of their functions are unknown. In this study, we examine the role of VC2323 (TehAVc) and its divergently transcribed LysR-family regulator VC2324 (TehRVc) in V. cholerae pathogenesis. We found that in V. cholerae C6706, the expression of tehAVc is dependent on TehRVc. VC2323 (TehAVc), homologous to the Escherichia coli tellurite resistance protein (TehAEc), differs from TehAEc in that TehAVc has no noticeable role in tellurite resistance but instead contributes to chloramphenicol resistance. Interestingly, both tehAVc and tehRVc mutants were defective in colonization of infant mice. Though the expression of a key virulence gene tcpA was not affected in either of these mutants, tehAVc mutants failed to attach to mouse intestinal surfaces in the presence of crude bile, suggesting a new role of the TehAVc-TehRVc pair in V. cholerae pathogenesis.

Corynebacterium diphtheriae putative tellurite-resistance protein (CDCE8392_0813) contributes to the intracellular survival in human epithelial cells and lethality of Caenorhabditis elegans

“…One of the chromosomal Te R determinants is the operon teh AB, originally described in E. coli . Homologues and orthologues of the teh A gene have been identified in other bacterial species, such as Vibrio cholerae, Klebsiella pneumoniae, Salmonella enterica and Corynebacterium glutamicum ( Chasteen et al 2009 , Pei et al 2013) . Recent studies have revealed that this determinant did not confer the Te R mechanism of V. cholerae C6706, but was found involved in antibiotic resistance and intestinal colonisation ( Pei et al 2013) .…”

“…A recent report indicated that TehA protein participates in V. cholerae antimicrobial resistance ( Pei et al 2013 ). In contrast, the findings presented here indicated that the TehA homologue is not involved in the susceptibility of C. diphtheriae to the antimicrobial agents tested.…”

“…Although little is known about the mechanisms of TeO 3 2- -resistance (Te R ), numerous plasmid and/or chromosomally encoded Te R determinants have been identified in different bacterial species, including human pathogens. The presence of Te R determinants in pathogenic bacteria suggests that these genes might provide some selective advantage in the environment and might also be associated with pathogenicity ( Pei et al 2013 , Franks et al 2014 ). Previous studies have demonstrated that these determinants are involved in resistance to bacteriophages and colicins ( Whelan et al 1995 ), antiseptics and disinfectants ( Teitzel & Parsek 2003 ) and antimicrobials ( Collins et al.…”

“…Previous studies have demonstrated that these determinants are involved in resistance to bacteriophages and colicins ( Whelan et al 1995 ), antiseptics and disinfectants ( Teitzel & Parsek 2003 ) and antimicrobials ( Collins et al. 2010 , Pei et al 2013 , Franks et al 2014) . In addition, these genes have also been implicated in adherence to epithelial cells ( Yin et al.…”

“…In addition, these genes have also been implicated in adherence to epithelial cells ( Yin et al. 2009 , Pei et al 2013) and susceptibility to reactive oxygen species (ROS) ( Franks et al. 2014) .…”