Truncation in the core oligosaccharide of lipopolysaccharide affects flagella-mediated motility in Pseudomonas aeruginosa PAO1 via modulation of cell surface attachment

Abstract

In many Gram-negative bacterial species, rough strains producing truncated lipopolysaccharide (LPS) generally exhibit defects in motility compared with smooth strains. However, the role that LPS plays in bacterial motility is not well understood. The goal of this study was to examine the relationship between LPS defects and motility of Pseudomonas aeruginosa. P. aeruginosa wildtype strain PAO1 and three isogenic mutants with defects in the rmlC, migA and wapR genes and producing truncated core oligosaccharide were investigated in terms of motility, attachment to glass and flagella expression. Compared with the wild-type, the three mutants showed significant retardation in both swarming motility on 0.5 % soft-agar plates and swimming motility on 0.3 % soft-agar plates. Moreover, attachment to abiotic surfaces was observed to be stronger in these mutants. The assembly of flagella appeared to be intact in these strains and the ability of individual cells to swim was unaffected. Flagellin proteins prepared from mutants rmlC and rmd, defective in the production of TDP-L-rhamnose and GDP-D-rhamnose, respectively, were compared and a change in molecular mass was observed only in the rmlC mutant. These data indicated that L-rhamnose, and not its enantiomer, D-rhamnose, is incorporated into the flagellin glycan of P. aeruginosa PAO1. The nucleotide-activated sugar precursor TDP-L-rhamnose is therefore shared between LPS biosynthesis and flagellin glycosylation in P. aeruginosa PAO1. Our results suggest that although biochemical precursors are shared by LPS and flagellin glycan biosynthesis, LPS truncations probably alter flagella-mediated motility in P. aeruginosa by modulating cell-surface attachment but not flagella synthesis.

The Swarming Motility of Pseudomonas aeruginosa Is Blocked by Cranberry Proanthocyanidins and Other Tannin-Containing Materials

“…2A). This pattern is in agreement with other studies investigating P. aeruginosa swarming motility (22,36). In the presence of CPAC or PG, the bacteria were able to grow and form a colony in the center but exhibited no tendril formation or other features indicative of swarming motility ( Fig.…”

The Sweet Tooth of Bacteria: Common Themes in Bacterial Glycoconjugates

“…In P. aeruginosa strain PAO1, both the LPS and glycoprotein biosynthesis pathways use the TDP-L-Rha precursor (558). This is also the case for C. jejuni NCTC 11168, where the same Gne epimerase (CJ1131c) is involved in the production of Gal and/or GalNAc precursors, which are present on its N-glycoproteins and LOS and CPS structures (14,114).…”

Analysis of the Pseudomonas aeruginosa Regulon Controlled by the Sensor Kinase KinB and Sigma Factor RpoN

“…Swimming and swarming assays were performed as described previously (33). Briefly, strains were grown overnight on tryptic soy agar (TSA; Remel) and used to inoculate freshly prepared TSA plates with either 0.4% agar (swimming) or 0.5% agar (swarming).…”