Inability of encapsulated Klebsiella pneumoniae to assemble functional type 1 fimbriae on their surface.

We screened phase variants of Klebsiella pneumoniae isolates for the expression of capsule and type 1 fimbriae and found that all of the 22 blood isolates were encapsulated and did not express type 1 fimbriae while 10 of 11 urinary tract isolates expressed type 1 fimbriae but were unencapsulated. Phase variants from selected isolates were found to be either unencapsulated and fimbriated or lacked both structures. Variants expressing both structures were not detected. Fimbrial subunits FimH and FimA were localized in the periplasmic space of the parent strain and on the surface of the unencapsulated variants. The results suggest that capsule formation impedes assembly of pre-formed fimbrial subunits on the bacterial surface.

[1]  R. Podschun,et al.  Clinical, bacteriological, and serological aspects of Klebsiella infections and their spondylarthropathic sequelae , 1997, Clinical and diagnostic laboratory immunology.

[2]  C. Whitfield,et al.  The rcsA gene of Klebsiella pneumoniae O1:K20 is involved in expression of the serotype-specific K (capsular) antigen , 1991, Infection and immunity.

[3]  N. Blumenkrantz,et al.  New method for quantitative determination of uronic acids. , 1973, Analytical biochemistry.

[4]  K. Krogfelt,et al.  Direct evidence that the FimH protein is the mannose-specific adhesin of Escherichia coli type 1 fimbriae , 1990, Infection and immunity.

[5]  M. Mori,et al.  Biosynthesis of Klebsiella K2 capsular polysaccharide in Escherichia coli HB101 requires the functions of rmpA and the chromosomal cps gene cluster of the virulent strain Klebsiella pneumoniae Chedid (O1:K2) , 1991, Infection and immunity.

[6]  D. Sievers,et al.  Serotypes, hemagglutinins, siderophore synthesis, and serum resistance of Klebsiella isolates causing human urinary tract infections. , 1993, The Journal of infectious diseases.

[7]  H. Mobley,et al.  In Vivo Phase Variation of Escherichia coli Type 1 Fimbrial Genes in Women with Urinary Tract Infection , 1998, Infection and Immunity.

[8]  H. Towbin,et al.  Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications. , 1979, Proceedings of the National Academy of Sciences of the United States of America.

[9]  A. Siitonen,et al.  Fimbriation, capsulation, and iron-scavenging systems of Klebsiella strains associated with human urinary tract infection , 1992, Infection and immunity.

[10]  F. Jacob-Dubuisson,et al.  Adhesin presentation in bacteria requires molecular chaperones and ushers , 1992, Infection and immunity.

[11]  Ellen Jo Baron,et al.  Manual of clinical microbiology , 1975 .

[12]  W. Gross,et al.  Comparison of the antibody responses to the 77 Klebsiella capsular types in ankylosing spondylitis and various rheumatic diseases , 1994, Infection and immunity.

[13]  D. Wozniak,et al.  Genetic exchange of determinants for capsular polysaccharide biosynthesis between Klebsiella pneumoniae strains expressing serotypes K2 and K21a , 1993, Infection and immunity.

[14]  I. Ofek,et al.  Bacterial Adhesion to Cells and Tissues , 1994, Springer US.

[15]  J. Morris,et al.  Differential Expression of Vibrio vulnificus Capsular Polysaccharide , 1999, Infection and Immunity.

[16]  C. Forestier,et al.  Consequences of Reduction of Klebsiella pneumoniae Capsule Expression on Interactions of This Bacterium with Epithelial Cells , 1999, Infection and Immunity.

[17]  S. Hultgren,et al.  Neutrophil activation by nascent FimH subunits of type 1 fimbriae purified from the periplasm of Escherichia coli. , 1993, The Journal of biological chemistry.

[18]  P. Domenico,et al.  Polysaccharide capsule-mediated resistance to opsonophagocytosis in Klebsiella pneumoniae , 1994, Infection and immunity.

[19]  I. Ofek,et al.  Population shift in mannose-specific fimbriated phase of Klebsiella pneumoniae during experimental urinary tract infection in mice , 1985, Infection and immunity.

[20]  N. Sharon,et al.  Nonopsonic phagocytosis of microorganisms. , 1995, Annual review of microbiology.

[21]  P. Domenico,et al.  Reduction of capsular polysaccharide production in Klebsiella pneumoniae by sodium salicylate , 1989, Infection and immunity.

[22]  J. Goldhar.  Bacterial lectinlike adhesins: determination and specificity. , 1994, Methods in enzymology.

[23]  G. Ames.  Isolation and purification of periplasmic binding proteins. , 1994, Methods in enzymology.

[24]  M. M. Bradford.  A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. , 1976, Analytical biochemistry.