Interaction of Gram-Negative Bacteria with the Lysosomal Fraction of Polymorphonuclear Leukocytes I. Role of Cell Wall Composition of Salmonella typhimurium.

Wild-type Salmonella typhimurium and cell wall mutants with sequential deficiencies in their cell wall polysaccharide were examined for sensitivity to the bactericidal action of the lysosomal fraction of polymorphonuclear leukocytes. The complete lipopolysaccharide basal core was essential for resistance to the bactericidal action. O-specific side chains of the wild type did not enhance the resistance. Absence of N-acetyl glucosamine considerably enhanced sensitivity, whereas absence of other core sugars did not; additional increase in sensitivity was obtained when the heptose phosphate was absent. Under conditions where appropriate supplementation of the medium permitted complete cell wall synthesis, the uridine diphosphate-gal-4-epimeraseless mutant regained resistance that was essentially equal to that of the wild type. Cells coated with specific antiserum and nongrowing cells were more resistant than normal growing cells.