Phage-related surface modifications of Pseudomonas aeruginosa: effects on the biological activity of viable cells

Abstract

Lysogenic [EI(8)3] and phage 8-resistant mutant (EI/8s17) strains of Pseudomonas aeruginosa EI were isolated. Besides lacking the capacity to adsorb phage 8, strains EI(8)3 and EI/8s17 did not contain surface substrate for the depolymerase that is produced de novo when phage 8 infects wild-type strain EI. The glycolipoprotein (GLP) in the wild type contains phage 8 receptors and surface substrate for the depolymerase, as well as possesses characteristics of a virulence factor; therefore, the chemical and biological characteristics of the derived strains were investigated. The neutral-sugar, amino sugar, and protein content of the GLPs from the derived strains differed quantitatively from that of the wild type. In spite of some cross-reactivity, the GLPs from all strains were antigenically distinct in the indirect hemagglutination inhibition test. In mice, the toxicity of the GLP from strain EI(8)3 equaled that of the wild type, but the GLP of strain EI/8s17 was threefold less toxic. Significantly fewer viable EI(8)3 cells were required for the mouse 50% lethal dose than for the cells of either the wild type or the phage-resistant mutant.

Mannose-inhibitable adhesins and T3-T7 receptors of Klebsiella pneumoniae inhibit phagocytosis and intracellular killing by human polymorphonuclear leukocytes

“…As we pointed out previously (30), it should now be of interest to study whether any of the many cases of lysogenic conversion phenomena leading to changes in the cell surface antigens (3) might also be accompanied by changes in the sensitivity to phagocytosis. A case of lysogenic conversion causing changes both in phage receptors and in pathogenicity of the strain has recently been described in Pseudomonas aeruginosa (11).…”

Alginate production by clinical nonmucoid Pseudomonas aeruginosa strains

“…Other workers, using the methodology of Bartell and coworkers (3, 29) for the extraction of the GLP from the slime layer of nonmucoid P. aeruginosa, have shown that uronic acid is a constant component of all seven Fisher immunotypes. However, this uronic acid constituent had been considered as making up part of the GLP macromolecule and had not been characterized (2,10,19). Antibody agglutination supports the existence of alginate in RNMV (27), while animal studies have shown that active immunization with purified alginate results in pulmonary clearance of the RNMV of a MS by 30 days after injection and clearance was correlated with antibody to alginate (32).…”

“…The term slime has been used to denote extracellular substances of different chemical and physical characteristics such as neutral sugars (9), polysaccharide (7), hexosamine, and glucuronide (12) according to their extraction procedure. Bartell and co-workers have isolated a toxic glycolipoprotein (GLP) from the slime layers of all seven Fisher immunotypes with no qualitative and only certain minor quantitative differences from strain to strain (2,10,19,30).…”

Filamentous prophage capsid proteins contribute to superinfection exclusion and phage defence in Pseudomonas aeruginosa

“…The interaction of pVII with PilC/PilJ can provide host protection to pili-dependent lytic infection. lipopolysaccharide and glycolipoprotein receptors (Dimitracopoulos and Bartell, 1979;De Smet et al, 2017), could be potential candidates for use in phage cocktails. Our study also found that the pIII protein can still confer a certain level of antiphage activity against two lytic phages, namely, PAP8 and PAOP5, although the phage receptors have not been identified.…”