PSEUDOMONAS-AERUGINOSA PAO1 CEASES TO EXPRESS SEROTYPE-SPECIFIC LIPOPOLYSACCHARIDE AT 45-DEGREES-C

Most Pseudomonas aeruginosa strains are able to produce two distinct l ipopolysaccharide (LPS) O polysaccharide types, A-band (common-antigen ) and B-band (serotype-specific) LPSs. The relative expression levels of these two LPS types in P. aeruginosa PAO1 (O5 serotype) at various growth temperatures were investigated by sodium dodecyl sulfate-polyac rylamide gel electrophoresis and silver staining or Western blotting ( immunoblotting) with monoclonal antibodies specific for each O polysac charide. A-band and B-band LPSs were expressed concurrently when the c ells grew at 15, 25,and 35 degrees C however, growth at 45 degrees C r esulted in a surface deficiency in B-band LPS as determined by immunob lotting and agglutination with B-band-specific monoclonal antibody. Tr ansfer of these cells (expressing A-band LPS but deficient in B band L PS) [A(+)B(-)]) to a lower temperature (at which the division time was comparable) result in a rapid resumption of normal A-band and B-band expression. B-band LPS was detectable by immunoblotting before measura ble growth of the culture had occurred.