Virulence determinants of Escherichia coli O6 extraintestinal isolates analysed by Southern hybridizations and DNA long range mapping techniques.
A total of 16 Escherichia coli O6 strains isolated from cases of extraintestinal infections were analysed for the genetic presence and phenotypic expression of fimbrial adhesins (P, S/FIC, type 1), aerobactin and hemolysin. In addition restriction fragment length polymorphisms (RFLPs) of Xbal-cleaved genomic DNA of seven selected strains, separated by orthogonal field alternation gel electrophoresis (OFAGE) were determined and virulence-associated DNA probes were used for Southern hybridization studies of the Xbal-cleaved genomic DNAs. The virulence characteristics and hybridization patterns obtained differed between the various isolates. In three isolates hemolysin genes and P fimbrial determinants were located on the same Xbal fragments. Furthermore, multiple copies of FIC determinants (foc) could be detected in two strains. Our data show that the new technique of pulse field electrophoresis together with Southern hybridization represents a powerful tool for the genetic analysis of pathogenic bacteria.
Institut für Genetik und Mikrobiologie, University of Würzburg, Germany.
G
G
Blum
M
M
Ott
A
A
Cross
J
J
Hacker
D018830:Adhesins, Escherichia coli; D001425:Bacterial Outer Membrane Proteins / Q000032:analysis; D001426:Bacterial Proteins / Q000032:analysis; D015139:Blotting, Southern; D004269:DNA, Bacterial / Q000032:analysis*; D004587:Electrophoresis, Agar Gel; D004926:Escherichia coli / Q000235:genetics / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000235:genetics / Q000382:microbiology; D029968:Escherichia coli Proteins; D005784:Gene Amplification; D005798:Genes, Bacterial; D006460:Hemolysin Proteins / Q000032:analysis*; D006877:Hydroxamic Acids / Q000032:analysis; D010641:Phenotype; D012150:Polymorphism, Restriction Fragment Length; D014774:Virulence / Q000235:genetics
D018830:Adhesins, Escherichia coli; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D006460:Hemolysin Proteins; C036507:Hlya protein, E coli; D006877:Hydroxamic Acids; C031819:aerobactin