M031: BACTERIOLOGICAL STUDY OF SPUTUM-IN CF PATIENTS RECEIVING
ONCE-DAILY AMIKACIN FOR PSEUDOMONAS AERUGINOSA PULMONARY EXACERBATIONS.
F. Canis, MO Husson, Ph Vic, S Ategbo, V Launay, R Courcol,
H Leclerc, D Turck. Departments of Bacteriology and Pediatrics,
University Hospital, Lille, France.
The aim of the present work was to study the bacteriological efficiency of once-daily amikacin (35mg/Kg/day in one 30 min-perfusion) associated with ceftazidime (200mg/Kg/day in 3 IV injections) for the treatment of pulmonary exacerbations in CF patients chronically infected with Pseudomonas aeruginosa (PA). Bacteriological supervision of this treatment was performed: 1) by the determination of MlCs before and after treatment; 2) by the study of PA colonization of sputum immediately after this treatment and during an 11-month period ; 3) by the identification of PA strains with phenotypic methods (serotyping and antibiotyping) and with genotypic method (pulsed field gel electrophoresis). At the end of the treatment, PA was cleared from sputum in 15 of 18 patients. No PA strains were isolated in 9 of 18 patients during an 11-month period after treatment. MlCs of PA strains strongly influenced their reoccurrence in sputum. None of the 9 strains with MlCs of 0.5,1 or 2 mg/L recolonized the sputum of CF patients, as opposed to 1 of 8 strains with MIC of 4 mg/L, 6 of 8 strains with MIC of 8 mg/L and 2 of 2 strains with MIC of 16 mg/L. Serotyping and antibiotyping systems did not enable to study PA epidemiology because of variations of PA strains characteristics throughout the study period. Genome macrorestriction fingerprinting of PA in pulsed field gel electrophoresis showed that our patients were colonized with one or several clones. No variation of these clones as well as no cross- contamination between patients were noticed during the 11 months after treatment.
Supported by the French Ministry of Health.