Exopolysaccharide Sugars Contribute to Biofilm Formation bySalmonella entericaSerovar Typhimurium on HEp-2 Cells and Chicken Intestinal Epithelium

Abstract

Recently, we demonstrated that Salmonella enterica serovar Typhimurium can form biofilm on HEp-2 cells in a type 1 fimbria-dependent manner. Previous work on Salmonella exopolysaccharide (EPS) in biofilm indicated that the EPS composition can vary based upon the substratum on which the bacterial biofilm forms. We have investigated the role of genes important in the production of colanic acid and cellulose, common components of EPS. A mutation in the colanic acid biosynthetic gene, wcaM, was introduced into S. enterica serovar Typhimurium strain BJ2710 and was found to disrupt biofilm formation on HEp-2 cells and chicken intestinal tissue, although biofilm formation on a plastic surface was unaffected. Complementation of the wcaM mutant with the functional gene restored the biofilm phenotype observed in the parent strain. A mutation in the putative cellulose biosynthetic gene, yhjN, was found to disrupt biofilm formation on HEp-2 cells and chicken intestinal epithelium, as well as on a plastic surface. Our data indicate that Salmonella attachment to, and growth on, eukaryotic cells represent complex interactions that are facilitated by species of EPS.

Attachment and Biofilm Formation by Salmonella in Food Processing Environments

“…Kim & Wei (2009) noticed that flagellar assemply was important during biofilm formation on PVC in different (meat, poultry and produce) broths and on stainless steel and glass in LB broth. Colanic acid, a capsular extracellular polysaccharide, essential for S. Typhimurium biofilm development on epithelial cells was found not to be required for Salmonella biofilm formation on abiotic surfaces (Ledeboer & Jones, 2005;Prouty & Gunn, 2003). Solano et al (2002) showed that colonic acid was important to form a tight pellicle under LB conditions, while it was dispensable under ATM conditions.…”

Salmonella: Invasion, Evasion & Persistence

“…S. Typhi is known to form biofilms in abiotic and biotic surfaces and it is therefore not surprising that S. Typhi forms biofilms in the gall bladder (Ledeboer & Jones, 2005). Interestingly, however, formation of Salmonella biofilms on gallstones is dependent on the presence of bile (Prouty et al, 2002).…”

“…During these two latter stages, extracellular polymeric substances (EPS) help biofilm structural development and cell-cell interaction (Costerton et al, 1999). In S. Typhi infected gallbladders, EPS is primarily composed of cellulose, colanic acid, Vi capsular antigen, curli fimbriae, O antigen capsule and biofilm associated proteins (Gibson et al, 2006;GonzalezEscobedo et al, 2011;Jonas et al, 2007;Ledeboer & Jones, 2005). Although the role of some elements in the EPS remain minor, other elements such as cellulose, colonic acid and O antigen capsule are crucial for S. Typhi persistence and biofilm development (Crawford et al, 2008;Prouty & Gunn, 2003;Prouty et al, 2002).…”

Salmonella enterica Serovar Typhimurium Requires the Lpf, Pef, and Tafi Fimbriae for Biofilm Formation on HEp-2 Tissue Culture Cells and Chicken Intestinal Epithelium

“…These fimbriae are expressed in vitro after static growth for 48 h at 37°C. Our research group has recently demonstrated that these fimbriae are involved in biofilm formation on HEp-2 tissue culture cells, murine intestinal epithelium, and chicken intestinal epithelium (7,37).…”

“…Environmental signals regulating Tafi biosynthesis proceed through the csgD gene product that directly regulates expression of the major subunit CsgA (8,25,26,57). In addition to regulating expression of Tafi, CsgD also regulates cellulose biosynthesis (8,(24)(25)(26), a component of exopolysaccharides in Salmonella biofilms formed on some surfaces (24,37,53,54,60).…”