Identification of the lipopolysaccharide core region as the receptor site for a cytotoxin-converting phage, phi CTX, of Pseudomonas aeruginosa.
A temperate phage, phi CTX, is a cytotoxin-converting phage of Pseudomonas aeruginosa. In this study, we characterized the lipopolysaccharide (LPS) structures of phi CTX-resistant mutants derived from phi CTX-sensitive strains. phi CTX infectivity was neutralized by LPS preparations derived from sensitive strains but not by those from resistant strains. phi CTX-resistant mutants had lower-molecular-weight rough (R)-type LPS than the parental strains and lacked the reactivity of some anti-LPS core monoclonal antibodies. Some LPS core components were lacking or significantly decreased in the resistant mutants. These results suggested that a receptor site of the cytotoxin-converting phage phi CTX was the LPS core region and that especially L-rhamnose and D-glucose residues in the outer core were involved in phage binding. The host range of phi CTX was nearly O-serotype dependent, probably because of the diversity of the LPS core structure among P. aeruginosa strains. phi CTX bound to most strains of Homma serotypes A, G, and I but not to strains of serotypes B and E. Furthermore, we found that a genetic locus specifying phi CTX sensitivity (and consequently participating in the biosynthesis of part of the LPS core) existed in or near the locus participating in the determination of O-serotype specificity (somA), which has been mapped between leu-10 and eda-9001. phi CTX, as well as anti-LPS core monoclonal antibodies, will be a good tool for structural characterization of the P. aeruginosa LPS core region.
Yokota
S
S
Sumitomo Pharmaceuticals Research Center, Osaka, Japan.
Hayashi
T
T
Matsumoto
H
H
D000818:Animals; D000911:Antibodies, Monoclonal; D002240:Carbohydrate Sequence; D003227:Conjugation, Genetic; D003603:Cytotoxins / Q000096:biosynthesis; D006801:Humans; D008070:Lipopolysaccharides / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D009844:Oligosaccharides / Q000737:chemistry; D017105:Pseudomonas Phages / Q000502:physiology*; D011550:Pseudomonas aeruginosa / Q000145:classification / Q000276:immunology / Q000502:physiology*; D011991:Receptors, Virus / Q000378:metabolism*; D012703:Serotyping
D000911:Antibodies, Monoclonal; D003603:Cytotoxins; D008070:Lipopolysaccharides; D009844:Oligosaccharides; D011991:Receptors, Virus