Pseudomonas aeruginosa strains DNA typing by semi-automated repetitive-sequence-based PCR

Abstract number: R2375

Doléans-Jordheim A., Bergeron E., Croizé J., Salord H., Cournoyer B., André J., Mazoyer M.A., Renaud F.N.R., Freney J.

Background: Pulsed-Field Gel Electrophoresis (PFGE), based on the separation of long strands of DNA by length, is a highly discriminatory method. It is traditionally considered to be "the gold standard" for gene mapping and epidemiological studies. However, it presents some disadvantages since it takes several days to perform with specialised equipment and often laborious techniques. A typing method, not time consuming, is therefore needed to assess outbreaks in real time.

Objectives: the aim of this study was to evaluate the usefulness and the performance of the semi-automated repetitive-sequence-based polymerase chain reaction (rep-PCR) which examines non-coding highly conserved repetitive sequences, interspersed throughout the bacterial genome for typing Pseudomonas aeruginosa strains.

Method: the typing of 82 Pseudomonas aeruginosa strains by the DiversiLab system® was realised on the basis of an 95% similarity threshold, and results were compared with PFGE. Twenty-nine of these strains were unlinked strains, 16 were issued from 5 epidemic cases, 7 from an epidemiological study, 5 from members of two families and 25 from water, aerosols and patient isolates of the same hospital.

Results: a good correlation was observed between the semi-automated rep-PCR method and PFGE: the 29 strains were typed as different and most of the other strains were linked in the same way as with the PFGE method. However, two cases are discordant: one for which the source of contamination was not the same with the two methods and one for which results were not reproducible.

Conclusion: even if further studies must be performed to confirm the discriminatory power and the reproducibility of the rep-PCR method, this simple and fast technique seems to be appropriate to type Pseudomonas aeruginosa strains.

Session Details

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