Genotype based evaluation of Pseudomonas aeruginosa eradication treatment success in cystic fibrosis patients

Schelstraete, Petra; Deschaght, Pieter; Van Simaey, Leen; Van daele, Sabine; Haerynck, Filomeen; Vaneechoutte, Mario; De Baets, Frans

doi:10.1016/j.jcf.2009.11.006

« Previous Next »Journal of Cystic Fibrosis
Volume 9, Issue 2 , Pages 99-103, March 2010

Genotype based evaluation of Pseudomonas aeruginosa eradication treatment success in cystic fibrosis patients

Petra Schelstraete
- Cystic Fibrosis Center Gent, Ghent University Hospital, 9000 Gent, Belgium
- Corresponding author. Pediatric Pulmonology and Cystic Fibrosis Clinic, Ghent University Hospital, De Pintelaan 185, 9000 Gent, Belgium. Tel.: +32 9 332 2852; fax: +32 9 332 3861.
- These authors contributed equally in this article.
Pieter Deschaght
- Laboratory Bacteriology Research, Faculty of Medicine and Health Sciences, Ghent University, 9000 Gent, Belgium
- These authors contributed equally in this article.
- Pieter Deschaght is indebted to the IWT for PhD research grant IWT-SB/71184.
Leen Van Simaey
- Laboratory Bacteriology Research, Faculty of Medicine and Health Sciences, Ghent University, 9000 Gent, Belgium
Sabine Van daele
- Cystic Fibrosis Center Gent, Ghent University Hospital, 9000 Gent, Belgium
Filomeen Haerynck
- Cystic Fibrosis Center Gent, Ghent University Hospital, 9000 Gent, Belgium
Mario Vaneechoutte
- Laboratory Bacteriology Research, Faculty of Medicine and Health Sciences, Ghent University, 9000 Gent, Belgium
Frans De Baets
- Cystic Fibrosis Center Gent, Ghent University Hospital, 9000 Gent, Belgium

Received 28 September 2009; received in revised form 20 November 2009; accepted 23 November 2009.

Abstract

Background

Longitudinal data regarding the genotypes of Pseudomonas aeruginosa isolates after eradication treatment are limited. We followed cystic fibrosis patients after a first ever isolation of P. aeruginosa and evaluated the P. aeruginosa-free time period after eradication therapy.

Methods

Between January 2003 and December 2008 respiratory samples were cultured prospectively from 41 patients with a first ever P. aeruginosa isolate. Twenty five patients had at least one subsequent isolate. Treatment efficacy was assessed based on the time to a second isolation and on comparison of the RAPD genotypes of the P. aeruginosa isolates.

Results

Eleven patients became chronically colonized during the study period. For ten of these the second isolate had the same genotype as the first isolate. Moreover, these patients had a significantly shorter P. aeruginosa-free time interval between the first ever and the second isolate compared to the 14 not chronically colonized patients (median 0months versus 7.5months, p<0.05).

Conclusion

Our results indicate that the presence of a genotypically identical subsequent P. aeruginosa isolate and/or a short P. aeruginosa-free time interval after treatment are ominous signs and might be useful additional tools to predict impending chronic colonization. Current routine bacteriological methods for the detection of P. aeruginosa may lack the sensitivity to discriminate between true eradication and low bacterial persistence.

Keywords: P. aeruginosa, Eradication treatment efficacy, Genotyping