Lysogenization of Salmonella choleraesuis by phage 14 increases average length of O-antigen chains, serum resistance and intraperitoneal mouse virulence

• Published in: Microbial pathogenesis Vol. 8; no. 6; pp. 393 - 402
• Main Authors: Nnalue, Ndubisi A., Newton, Salete, Stocker, B.A.D.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier India Pvt Ltd 01.06.1990; Elsevier
• Subjects: Animals; Antigens, Bacterial - immunology; Bacteriology; Bacteriophages - immunology; Biological and medical sciences; Carbohydrate Sequence; Densitometry; Electrophoresis, Polyacrylamide Gel; Fundamental and applied biological sciences. Psychology; Humans; Lipopolysaccharides - analysis; Liver - microbiology; Lysogeny - immunology; Mice; Mice, Inbred BALB C; Microbiology; mouse virulence; O Antigens; O-antigen increase; Pathogenicity, virulence, toxins, bacteriocins, pyrogens, host-bacteria relations, miscellaneous strains; phage-conferred selective advantage; Salmonella - pathogenicity; Salmonella lipopolysaccharide; serum resistance; Spleen - microbiology; Virulence - immunology; phage-conferred selective advantage; mouse virulence; O-antigen increase; Salmonella lipopolysaccharide; serum resistance; Gel electrophoresis; Rodentia; Lysogeny; Host virus relation; Salmonella typhimurium; Antigen; Pathogenicity; Resistance; Vertebrata; Mammalia; O antigen; Mouse; Salmonella choleraesuis; Lipopolysaccharide; Bacteria; Serum; Escherichieae; Comparative study; Enterobacteriaceae
• ISSN: 0882-4010; 1096-1208
• DOI: 10.1016/0882-4010(90)90026-M

Three clones from a strain of Salmonella choleraesuis (serogroup C 1) were lysogenized with phage 14 (P14) which converts the O-antigen of serogroup C 1 salmonellae from O-6,7 to O-6,7,14. The lysogens were compared with their parental non-lysogenic clones with respect to the following properties: average length of O-antigen polysaccharide chains, sensitivity to normal human serum, and mouse-virulence. SDS-polyacrylamide gel electrophoresis of lipopolysaccharides extracted from these bacteria showed that samples from lysogens consisted mainly of long-chained molecules whereas those from non-lysogens contained mainly short-chained molecules. The O-antigen polysaccharide from a lysogen was estimated by chemical analysis to be six times as long as that from a non-lysogen. Lysogens were serum-resistant whereas non-lysogens were serum-sensitive. About 10 times more colony forming units of a lysogen than of a non-lysogen were recovered from the livers and spleens of mice on day 1 and 3 after intraperitoneal inoculation of equal doses. By comparison with S. choleraesuis, lysogenization of S. typhimurium with phage P22 or phage A4 did not affect the chain-length distribution of O-antigen polysaccharide. Our data suggest that phage 14-coded determinants increase efficiency of O-antigen biosynthesis in S. choleraesuis leading to increase in average length of O-polysaccharide chains. Increased serum resistance and mouse virulence are logical consequences of increase in average length of O-polysaccharide chains and represent phage-conferred selective advantage not previously described in Salmonella.