Chemical composition and biological functions of Listeria monocytogenes cell wall preparations

Abstract

A crude Listeria cell wall fraction, a purified fraction (PF) with demonstrated biological activity, as well as a third fraction of base-hydrolyzed PF (BHPF) were analyzed for chemical composition and activities not previously described. Listeria cell wall fraction and PF contained significant quantities of lipid, whereas BHPF was lipid depleted. Fatty acid compositions were typical of gram-positive bacteria. PF and BHPF were depleted in protein. Alanine, glutamic acid, diaminopimelic acid, glucosamine, and muramic acid were found in all fractions, in enhanced concentration in PF and BHPF, and with molar ratios typical of bacterial peptidoglycans. Major neutral sugars were rhamnose, ribose, ribitol, and glucose. The concentrations of rhamnose, ribose, and glucose were increased in BHPF. Differences in chemical composition of the fractions reflected differences in their biological activities: Listeria cell wall fraction induced resistance to Listeria infection, whereas PF did not. Mitogenic and adjuvant activities were demonstrated for Listeria cell wall fraction and PF but were lost in BHPF. BHPF retained the ability to induce macrophage-mediated tumoricidal activity and decrease resistance to Listeria infection.

Immunopotentiating activities of cell walls, peptidoglycans, and teichoic acids from two strains of Listeria monocytogenes

“…The TEICH fractions yielded the highest values, presumably reflecting ribitol or glycerol and attached glucose or galactose residues. These carbohydrate values agree with those previously reported (10,18,19).…”

“…This may indicate that the mitogenic component is a predominant constituent of the PEP fraction which in turn represents a major portion of the CCW. The mitogenic activitiy was not lost by the enzymatic treatment, agreeing with the literature (10).…”

“…Cell wall components from Listeria monocytogenes should be considered as potential immunomodulators, since they have been found to increase resistance to Listeria infection (16), act mitogenically (6,14), act as an adjuvant (3,4,17), fix complement and be chemotaxigenic (1), stimulate nonspecific immunity to Candida albicans and several tumors (11,14), stimulate macrophages to become tumoricidal (10,11), and elevate natural killer (NK) activity (14). This s'tudy reports the isolation of four different cell wall factions from two commonly used strains of L. monocytogenes and their comparison via electron microscopy, chemical analyses, and various immunological assays.…”

Antimicrobial activity of lysozyme against bacteria involved in food spoilage and food-borne disease

“…The results obtained with C. botulinum and L. monocytogenes suggest that two factors mainly limit the effectiveness of lysozyme. First, since EDTA is required to obtain consistent lysis, the peptidoglycan substrate may be partially masked by other cell wall components (7,12,20). EDTA could allow partial removal of these layers and promote penetration of lysozyme to the peptidoglycan.…”

Lipoteichoic acid from Listeria monocytogenes

“…Included in this class of bacterial polymers are capsular, cell wall, and membrane polymers containing glycerol phosphate or ribitol phosphate (20,23,39). Listeria serotype 4b does not appear to have teichoic acids (34), whereas serotype 1 cells contain abundant quantities of ribitol (18). Ribitol in serotype 1 cells suggests the presence of teichoic acids.…”