[Pseudomonas aeruginosa infection in cystic fibrosis: predominance of a single strain and the influence of antibiotic therapy and the environment].
We analysed the implantation pattern and persistence of Pseudomonas aeruginosa in the tracheobronchial tracts of patients with cystic fibrosis, and investigated the relation of this bacterium with the environment and antibiotic therapy. We used four different techniques to ensure the precise and detailed identification of isolates. In particular, chromosomal differences were assessed by pulsed field electrophoresis (pulsotype determination). Sputum samples were collected from 8 patients, from 6 to 22 years-old, over a period of 19 to 24 months. Only a single strain was isolated from samples from each five patients taken at different times, and there was a predominant strain in the samples from two others. Patient 8, aged 14, was free of infection throughout the study. None of the infections was eradicated by antibiotic therapy (an association of two antibiotics for 15 days at one or two months interval). The strains isolated from two patients became resistant to imipenem: 3 out of the 4 resistant strains were the result of mutation in the resident, susceptible strain. Swabs were taken from the environments of infected patients and were tested for P. aeruginosa: this bacteria was found in three sites, and two of these contained an isolate with the same pulsotype as the strain responsible for the infection, whereas no P. aeruginosa was detected in the environment of an uninfected patient. The detailed and accurate identification of the isolates (by pulsotyping) enabled us--to show that each infected patient was infected by a single or predominant strain,--to investigate the relationship of these strains with those in the environment and the effects of antibiotic therapy.
Michel-Briand
Y
Y
Laboratoire de Bactériologie-Hygiène, Faculté de Médecine, Hôpital Jean Minjoz, Besançon.
Plesiat
P
P
Godard
C
C
Noir
A
A
Estavoyer
J M
JM
D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents; D002648:Child; D003550:Cystic Fibrosis / Q000150:complications*; D004269:DNA, Bacterial / Q000235:genetics; D004359:Drug Therapy, Combination / Q000627:therapeutic use*; D004783:Environmental Microbiology; D006801:Humans; D011552:Pseudomonas Infections / Q000150:complications* / Q000188:drug therapy; D011550:Pseudomonas aeruginosa / Q000145:classification / Q000302:isolation & purification*
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial
Infection à bacille pyocyanique au cours de la mucoviscidose: prédominance d'un clone, influence des antibiotiques et de l'environnement.