Fimbriation, capsulation, and iron-scavenging systems of Klebsiella strains associated with human urinary tract infection.
Thirty-two strains of Klebsiella pneumoniae and seven strains of Klebsiella oxytoca isolated from urinary tract infections in elderly adults were analyzed for capsular antigens, iron-scavenging systems, and fimbriation. All strains were capsulated. Twenty-seven different K antigens were identified among the strains, with no particular antigen dominating. All strains produced the iron-scavenging system enterochelin as analyzed by bioassay and DNA hybridization. In contrast, the aerobactin iron-sequestering system was not detected in any of the strains. All strains caused hemagglutination of tannin-treated human erythrocytes and reacted with an anti-type 3 fimbriae antiserum as well as in DNA hybridization with a type 3 fimbria-specific probe, indicating that the Klebsiella strains possessed this fimbrial type. Possession of type 1 fimbriae was analyzed by agglutination tests and by hybridization with DNA probes from two distinct Klebsiella type 1 fimbria gene clusters. Phenotypic expression of the type 1 fimbriae was found in 29 of 32 K. pneumoniae strains, whereas 30 strains reacted with either of the two type 1 fimbrial cluster DNA probes. In K. oxytoca, however, only three of seven strains expressed type 1 fimbriae and reacted with the DNA probes. The type 3 fimbriae were found to bind to a fraction of epithelial cells exfoliated in normal human urine, whereas the type 1 fimbriae bound strongly to urinary slime. No inhibitors of type 3 fimbrial binding were detected in human urine.
Department of General Microbiology, University of Helsinki, Finland.
A M
AM
Tarkkanen
B L
BL
Allen
P H
PH
Williams
M
M
Kauppi
K
K
Haahtela
A
A
Siitonen
I
I
Orskov
F
F
Orskov
S
S
Clegg
T K
TK
Korhonen
D000368:Aged; D000942:Antigens, Bacterial; D000954:Antigens, Surface / Q000032:analysis; D001422:Bacterial Adhesion; D005260:Female; D010861:Fimbriae, Bacterial / Q000502:physiology*; D006801:Humans; D007223:Infant; D007501:Iron / Q000378:metabolism*; D007709:Klebsiella / Q000502:physiology*; D008297:Male; D014552:Urinary Tract Infections / Q000382:microbiology*
D000942:Antigens, Bacterial; D000954:Antigens, Surface; C030659:K antigens; D007501:Iron