Characterization of lipopolysaccharide-deficient mutants of Pseudomonas aeruginosa derived from serotypes O3, O5, and O6

Abstract

Well-characterized rough mutants are important for the understanding of structures, functions, and biosynthesis of lipopolysaccharide (LPS) in gram-negative organisms. In this study, three series of Pseudomonas aeruginosa LPS-deficient mutants, namely PAC strains derived from serotype 03, AK strains derived from strain PA01 (serotype 05), and serotype 06-derived mutants were subjected to biochemical analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and silver staining as well as immunochemical characterization using LPS-specific monoclonal antibodies. The 0-side-chain deficiency among the 06-derived mutants was also examined, and three mutants, A28, R5, and H4, were subsequently chosen for the elucidation of component sugars of the core structure of serotype 06 LPS. LPS of strain A28 has L-rhamnose and proportionally higher amounts of D-glucose, a feature shared by the 05-derived mutant, strain AK1401

Structural elucidation of the lipopolysaccharide core regions of the wild‐type strain PAO1 and O‐chain‐deficient mutant strains AK1401 and AK1012 from Pseudomonas aeruginosa serotype O5

“…Another part of the core OS was dephosphorylated with 48% HF, to give dephosphorylated core OS. Results of the chemical analysis of the core and HF-treated core OS from mutant strains AK1012 and AK1401 were reported earlier [16]. The chemical compositions of the core and HF-treated core for the PAO1 LPS were very similar to that of the AK1401 mutant, and consisted of D-Glc, D-GalN, L-Rha, L,D-Hep and L-alanine.…”

“…For the core OS of serotype O5, only a tentative structure has been reported [14,15]. We have also reported data on the structure of the core region of P. aeruginosa serotype O5 core-deficient-mutant strain AK1012 and core-sufficient strain AK1401 [16,17].…”

Biosynthesis of uronamide sugars inPseudomonas aeruginosaO6 andEscherichia coliO121 O antigens

“…The O antigen of P. aeruginosa is important in the context of human and animal infection (Cryz Jr et al, 1984;Dasgupta et al, 1994), and is also a major factor influencing the efficiency of bacterial adherence to surfaces (Makin and Beveridge, 1996;Beveridge et al, 1997), which is the initial step in biofilm formation. Production of O antigen is a regulated process in P. aeruginosa, with reduction in O antigen constituting a mechanism or consequence of cell differentiation during biofilm maturation (Beveridge et al, 1997;Lau et al, 2009).…”

Pseudomonas aeruginosa antigens as potential vaccines

“…A recent study by Tang et al [226] using both a wild-type strain and an LPS-de¢cient mutant in a neonatal mouse challenge model further con¢rmed the role of LPS in the pathogenic process P. aeruginosa infections. In addition, other studies have demonstrated that mutants with R-LPS are usually sensitive to human serum [227,228]. Therefore, strategies to develop interventions targeting enzymes involved in LPS biosynthesis or chain polymerization could render the bacteria harmless to the host.…”