Screening of TnPhoA Mutants of Vibrio Cholerae O139 for Identification of Antigens Involved in Colonisation

Abstract

A new serogroup of Vibrio cholerae non-01, designated as 0139, has emerged causing cholera-like disease among adults. Laboratory and field studies clearly show that there is no cross-protection between 01 and 0139 pathogenic strains. Since colonisation of the intestine is a most important step in the pathogenesis of cholera caused by 01 strains and colonising antigens are known to be protective, investigation of the colonising antigens of 0139 strain was initiated. By TnphoA mutagenesis, mutants were generated with insertions in the genome encoding membrane spanning or secretory proteins. Screening of the mutants for adherence to rabbit intestinal surface and colonisation in 5-day-old mice resulted in the identification of mutant clones, which were less adhesive than was the wild-type parent strain and which could not efficiently colonise the gut. Such non-colonising strains were attenuated in virulence. Analysis of the proteins by SDS-PAGE revealed that the non-colonising membrane protein.

Genetic Characterization of a New Type IV-A Pilus Gene Cluster Found in Both Classical and El Tor Biotypes of Vibrio cholerae

“…Thus, the nature of outer membrane proteins that may be essential for adherence could probably be identified only by screening of transposon mutants for defects in adherence in vitro. Such an approach has identified a 40-kDa outer membrane protein from V. cholerae O139 that shows decreased adherence and infant mouse colonization, although the disrupted gene has not yet been identified (5).…”

Vibrio choleraepersistence in aquatic environments and colonization of intestinal cells: involvement of a common adhesion mechanism

“…The ability of V. cholerae to adhere to animal cells has long been studied [17,18] and different ligands involved in intestinal colonization have been investigated, including virulence-associated toxin co-regulated pilus (TCP) [19][20][21][22], outer membrane proteins [17,18,23,24], and lipopolysaccharide [25]. Its interactions with substrates present in the aquatic environment have been described more recently.…”

Evaluation of different subcellular fractions ofVibrio choleraeO139 in protection to challenge in experimental cholera

“…The membrane fraction was enriched in two proteins of 40 and 37 kDa. The 37 kDa protein is unique to O139 strains but purified protein was not protective and the moderate protection given by membrane proteins was largely due to 40 kDa outer membrane protein [29]. A number of proteins were common between O1 and O139 strains.…”