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Ribotyping in molecular epidemiological studies of uropathogenic Escherichia coli. A critical assessment

Abstract number: P1686

Strand L., Jenkins A., Grude N., Mykland H., Allum A.G., Kristiansen B.E., Potaturkina-Nesterova N.I.

Objectives: To compare PCR phylogrouping and ribotyping in epidemiological study of uropathogenic E. coli.

Methods: Fluroquinolone resistant (N=35) and sensitive (N=31) UTI isolates, commensal isolates (N=20) from Norway and UTI isolates from Russia (N=31) were investigated. Isolates were typed using PCR phylogrouping, Ribotyping and PFGE. Minimal inhibitory concentrations were determined for ampicillin, mecillinam, nitrofurantoin, sulphonamide, trimethoprim, tetracycline, nalidixic acid, ciprofloxacin, gentamicin and chloramphenicol. Virulence factors (type 1, P, and S fimbriae, papG class I, II and III, haemagglutinin, capsule K1, capsule K5, aerobactin and hemolysin) were detected by multiplex PCR.

Results: 33 ribotypes were found. 7 groups of similar ribotypes could be identified (Ribogroups RiboA–G). There was evident correlation between ribogroup and country of origin, biological source and fluoroquinolone resistance. Phylogroup correlated with ribotype and ribogroup but correspondence was not perfect. Ribogroup G was predominantly phylogroup D, urovirulent, and related to clonal group A (CgA). Antibiotic resistance (excepting fluoroquinolone) and virulence profiles were unrelated to ribogroup. Isolates with similar PFGE patterns had similar, but not always identical ribotypes.

Conclusion: Ribotyping is a convenient, but costly typing method that correlates with clinically relevant biological parameters and geographical origin. Surprisingly, ribotypes are not homogeneous with respect to phylogenetic group, suggesting that the genetic loci tested may be subject to horizontal exchange, which might limit the value of these methods. The identification of a ribotype group, riboG, consisting of predominantly urovirulent Phylogroup D may provide insights into the origin of the urovirulent clonal group A (CgA).

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Subject:
Location: Barcelona, Spain
Presentation type:
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