Hyperadhesive mutant of type 1-fimbriated Escherichia coli associated with formation of FimH organelles (fimbriosomes)

Department of Medicine, University of Tennessee, Memphis.
Infection and Immunity (Impact Factor: 3.73). 06/1988; 56(5):1023-9.
Source: PubMed


The relationships of the genes and gene-products mediating D-mannose-specific attachment of type 1 fimbriae of Escherichia coli to eucaryotic cells were investigated by deletion mutation analysis of recombinant plasmid pSH2, which carries the genetic information for the synthesis and expression of functional type 1 fimbriae. Mutant pUT2004 was derived by a deletion remote from the structural gene encoding the 17-kilodalton (kDa) subunit protein of type 1 fimbriae. Phenotypically, the mutant demonstrated an eightfold-higher mannose-specific hemagglutination titer than the parent strain. On electron microscopy, the mutant strain expressed the same number of fimbriae as the parent strain. However, numerous 10-nm-diameter rounded structures (fimbriosomes) were observed both closely associated with fimbriae and in the culture medium. Fimbriosomes isolated from the medium agglutinated guinea pig erythrocytes in a mannose-sensitive manner. Dissociation of the fimbriosomes yielded a single 29-kDa protein, as demonstrated by sodium dodecyl sulfate gel electrophoresis. Antibodies raised against fimbriosomes reacted with a 29-kDa protein on immunoelectroblots of dissociated type 1 fimbriae and also blocked the adherence of other strains of type 1 fimbriated E. coli to eucaryotic cells. These findings suggest that the enhanced adhesive properties of the mutant pUT2004 strain are associated with overproduction of the 29-kDa FimH in the form of fimbriosomes which contain the determinant of the D-mannose-sensitive adhesion of type 1 fimbriae.

Download full-text


Available from: Jon D Goguen, Sep 30, 2015
13 Reads
  • Source
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Strains of Klebsiella pneumoniae are known to express two morphologically and functionally distinct filaments, the type 3 and the type 1 fimbriae. The gene (mrkD) encoding the adhesion of K. pneumoniae type 3 fimbriae was identified by transcomplementation analysis with the pap fimbrial gene cluster of Escherichia coli. The nucleotide sequence of the mrkD gene was determined. In addition, the determinant coding for the K. pneumoniae type 1 fimbrial adhesion was identified, and its nucleotide sequence was deduced. The predicted amino acid sequences of the K. pneumoniae adhesion proteins are compared, and similarities with the major fimbrial structural proteins (MrkA and FimA) are discussed.
    Journal of Bacteriology 04/1989; 171(3):1262-70. · 2.81 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Deletions within the cloned genes (fimA) encoding the type 1 major fimbrial subunits of two isolates of Klebsiella pneumoniae resulted in a nonfimbriate but hemagglutinating phenotype after transformation of Escherichia coli HB101 or ORN103. Phenotypic expression of type 1 fimbriae could be restored by transformation with plasmids containing the fimA genes of the fimbrial gene clusters from different strains. The surface fimbriae expressed were serologically identical to those of the polymerized product of the introduced fimA gene. The fimA gene products of Salmonella typhimurium and Serratia marcescens could utilize the accessory fimbrial genes of K. pneumoniae to produce surface-associated, hemagglutinating fimbriae. The relatedness of the type 1 fimbrial gene clusters from multiple isolates of members of the family Enterobacteriaceae was examined by DNA hybridization techniques. These analyses demonstrated little nucleotide sequence agreement among distinct genera of the enteric bacteria.
    Infection and Immunity 04/1989; 57(3):764-70. · 3.73 Impact Factor
Show more