Altered colonizing ability for the ceca of broiler chicks by lipopolysaccharide-deficient mutants of Salmonella typhimurium

Avian Dis. Jul-Sep 1994;38(3):401-8.


Salmonella typhimurium strain 3333/O was used to assess the role of bacterial lipopolysaccharide (LPS) in intestinal colonization of broiler chicks by salmonellae. LPS-defective TnPhoA mutants of this strain were isolated. The sensitivities of the mutants to smooth and rough phages and LPS banding patterns in sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated a defect in the polysaccharide side chain of the LPS molecule. Colonization was determined by orally administering 10(8) cells each of the wild-type and/or the mutant strains per chick and counting the colony-forming units (CFU) from the ceca 1 to 3 weeks after gavage. CFU of chicks given the LPS-deficient strains either were not detected or were significantly lower than the CFU from chicks given the wild-type strain. The incidence of the wild-type strain in spleens was higher than incidence of the mutant strains. In vitro binding studies with LPS-deficient mutants derived in this study and from S. typhimurium LT2 suggest that LPS side-chain components may shield the bacterial cell from entrapment in the chicken mucus. The LPS layer appears to enhance persistence of Salmonella in the avian intestinal tract.

MeSH terms

  • Animals
  • Bacterial Adhesion / genetics
  • Bacterial Adhesion / physiology
  • Cecum / microbiology*
  • Chickens / microbiology*
  • In Vitro Techniques
  • Lipopolysaccharides / toxicity*
  • Mucus / microbiology
  • Mutation
  • Salmonella typhimurium / genetics
  • Salmonella typhimurium / growth & development*
  • Salmonella typhimurium / pathogenicity
  • Virulence / genetics
  • Virulence / physiology


  • Lipopolysaccharides