M039: Clonal Analysis of Pseudomonas Aeruginosa from Chronically
Colonized Patients with Cystic Fibrosis: The value of phenotypic
versus genotypic procedures.
Nicole Renders, Alex van Belkum, Afonso Barth*, Wil Goessens,
Johan Mouton and Henri Verbrugh. (Department of Bacteriology,
University Hospital Dijkzigt, Rotterdam, The Netherlands &
*Central Public Health Laboratory, London, United Kingdom.1
Multiple typing methods have been used for typing Pseudomonas aeruginosa strains of chronically colonized patients with cystic fibrosis. The value of phenotyping and pulse field gel electrophoresis (PFGE) for epidemiological and longitudinal study have been described. We investigated the value of arbitrary primed PCR (AP PCR) versus PFGE and two phenotyping methods. Two p. aeruginosa sputum isolates were obtained with an interval of at least 29 months from 29 cystic fibrosis patients. Fifty-eight strains were included to evaluate the discriminatory capacity of the AP PCR versus PFGE, sero- and pyocin typing techniques. Results showed that AP PCR and PFGE have enhanced resolution when compared to sero- and pyocin typing. Comparing the results of the two genotypic analyses, concordant conclusions with respect to strain identity were obtained in 75 % of the cases. In contrast for sero- and pyocin typing the percentage concordance was 58 % only. Even lower percentages of homology were found when genotypic and phenotypic results were compared.
Conclusion : AP PCR and PFGE are valuable methods for studying clonal relationship of P. aeruginosa from cystic fibrosis patients.