Comparison of the Chemical Structure and Biological Activities of the Glycolipids of Salmonella minnesota R595 and Salmonella typhimurium SL1102

Abstract

It has been assumed in the past that the lipid moieties of endotoxic lipopolysaccharides are quite similar if not identical. This has been tested in the reported work here, where the chemical composition and biological activities of the glycolipids of two heptoseless Re mutants, Salmonella minnesota R595 and Salmonella typhimurium SL1102, have been studied and compared. The two glycolipids, extracted with chloroform-methanol (4:1), showed identical thin-layer chromatographic patterns. The molar ratios for hexosamine, fatty acids, phosphorus, 2-keto-3-deoxyoctonate, total amines, and total nitrogen of the purified glycolipids were in the same range, but small differences could be established. Both glycolipids contained the same major fatty acids, i.e., lauric, myristic, palmitic, and 3-hydroxymyristic acids, in similar but not identical ratios. On paper electrophoresis, the acid hydrolysates of the two glycolipids showed analogous components. In the determination of molecular weight, whereas S. minnesota R595 glycolipid did not show concentration dependence, the molecular weight measured for S. typhimurium SL1102 increased with its concentration. The molecular weight of the fully endotoxic R595 glycolipid has been found to be 17,000 ± 1,500. Both glycolipids showed similar activities in the Shwartzman skin reaction, Limulus-lysate clotting assay, mouse lethality, and enhancement of nonspecific resistance, but the R595 preparation appeared to be more active on a weight basis in some parameters than SL1102. Using passive hemagglutination, we observed cross-reactivity between the glycolipids. In the gel-diffusion test, they revealed clear identity. The antiserum against S. minnesota R595 neutralized the Shwartzman skin reactivity not only of R595 but also of SL1102 glycolipid. These results confirm that there are identical immunodeterminant group(s) in the two glycolipids. On the other hand, chemical analytical data for two glycolipids showed only similarities, indicating that although both glycolipids are of comparable chemical nature, differences between them exist.

Susceptibility of Lipopolysaccharide Mutants to the Bactericidal Action of Human Neutrophil Lysosomal Fractions

“…E. coli O111:B4 and its Re mutant RC59 were obtained from Loretta Leive of the National Institutes of Health (16,26). S. typhimurium SL1027 and its Re mutant SL1102 and Salmonella minnesota 1114 and its Re mutant R595 were gifts of Alois Nowotny of Temple University (28). Bacteria were grown to stationary phase overnight in Trypticase soy broth with or without aeration.…”

Relationship of Structure to Function in Bacterial Endotoxins: Serologically Cross-reactive Components and their Effect on Protection of Mice against some Gram-negative Infections

“…Our earlier in vitro studies (Ng et al, 1974) showed that anti-S. minnesota R595 serum cross-reacted with S. minnesota R595 and S. typhimurium SLI 102 Re glycolipids. The same serum neutralized the endotoxicity not only of these two glycolipids, but of LPS from smooth S. minnesota as well.…”

Myeloperoxidase-Cl--H2O2 bactericidal system: effect of bacterial membrane structure and growth conditions

“…Salmonella typhimurium LT-2 and its deep rough mutant TA2168 were obtained from Hiroshi Nikaido of the University of California, Berkeley (9). S. typhimurium SL1027 and its deep rough mutant SL1102 and S. Minnesota 1114 and its deep rough mutant R595 were gifts of Alois Nowotny of Temple University (5). All of the smooth bacteria contained complete "O" antigens, while all of the deep rough mutants lacked all "O" antigen, core polysaccharide, and heptoses.…”