TABLE 2.

Summary of the role of LPS, EPS, motility, and RpoS in glass versus gallstone biofilms

Mutant genePhenotype of gene mutantAbilitya to form biofilm on:
GallstoneGlass
phoPLoss of PhoPQ two-component system++++
prgHLoss of type III secretion apparatus
motAInability to rotate flagellum+
fliALoss of flagellum
galEPleiotropic; EPS synthesis defect and loss of LPS O antigen
rfaDInability to add O antigen to LPS+
bcsInability to synthesize cellulose EPS+
wcaInability to synthesize colanic acid EPS++
rpoSLoss of stationary-phase sigma factor
  • a Ability of strain to form a biofilm on gallstones as observed by SEM and on glass slides as observed by ruthenium red staining. ++, enhanced biofilm formation as compared to that by the wild type; −, severe defect in or complete loss of biofilm formation capability; +, normal wild-type biofilm formation.