STRUCTURAL AND SEROLOGICAL STUDIES OF LIPOPOLYSACCHARIDES OF CITROBACTER O35 AND O38 ANTIGENICALLY RELATED TO SALMONELLA

Structural analysis using C-13 NMR spectroscopy and methylation showed that lipopolysaccharides (LPSs) of Citrobacter freundii O35 and Salmo nella arizonae O59 have structurally identical O-specific polysacchari de chains, and those of C. freundii O38 and Salmonella kentucky differ only in the presence of O-acetyl groups in the former. Serological re lationships between the structurally similar LPSs were demonstrated us ing inhibition of ELTSA, rocket immunoelectrophoresis, double gel diff usion, and immunoblotting. The O-acetyl groups present in C. freundii O38 LPS are of little importance for its serological specificity. A cr oss-reaction was observed in immunoblotting between O-antisera to C. f reundii O35 and S. arizonae O59 and a structurally related LPS of Pseu domonas aeruginosa O11a,11b (Lanyi-Bergan classification).