Construction and characterization of type 1 non-fimbriate and non-adhesive mutants of Salmonella typhimurium

• Published in: FEMS immunology and medical microbiology 1997-12, Vol.19 (4), p.289-296
• Main Authors: Hancox, Lisa S, Yeh, Kuang-Sheng, Clegg, Steven
• Format: Article
• Language: English
• Subjects: Adherence; Adhesins, Bacterial - biosynthesis; Adhesins, Bacterial - chemistry; Adhesins, Bacterial - genetics; Adhesins, Escherichia coli; Amino Acid Sequence; Bacterial Adhesion - genetics; Bacterial Adhesion - physiology; Bacteriology; Base Sequence; Biological and medical sciences; Blotting, Southern; Cell Line; DNA, Bacterial - chemistry; Fimbriae Proteins; Fimbriae, Bacterial - chemistry; FimH; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Bacterial; Genetics; HeLa Cells; Hemagglutination Tests; Humans; Microbiology; Molecular Sequence Data; Multigene Family - genetics; Mutagenesis, Insertional; Mutant; Phenotype; Polymerase Chain Reaction; Recombinant Fusion Proteins - chemistry; Salmonella; Salmonella typhimurium - genetics; Salmonella typhimurium - ultrastructure; Sequence Analysis, DNA
• ISSN: 0928-8244; 1574-695X
• DOI: 10.1016/S0928-8244(97)00095-3

Mutations in the fimH gene of Salmonella typhimurium result in a non-fimbriate, non-adhesive phenotype. This phenotype was shown to be due to the lack of both fimH and fimF expression since disruption of the fimH gene by insertion of a DNA cassette into this determinant results in mutants that are complemented by plasmids carrying both fimH and fimF. Deletion mutations within the S. typhimurium fimH gene carried on a recombinant plasmid can be used to complement the mutant, and these transformants are non-adhesive but fully fimbriate, consistent with the role of FimH as being necessary for fimbrial adhesin expression. Adherence to erythrocytes, HeLa, and Hep-2 cells is associated with expression of the FimH polypeptide, and fimbriate strains that cannot synthesize FimH are non-adhesive. Discrete differences in the amino acid sequences of the adhesive type 1 and the non-hemagglutinating type 2 FimH polypeptides were detected, and are most likely responsible for the differences in hemagglutinating activity.