Development of antibiotic resistance in Pseudomonas aeruginosa during two decades of antipseudomonal treatment at the Danish CF Center.

TY - JOUR

T1 - Development of antibiotic resistance in Pseudomonas aeruginosa during two decades of antipseudomonal treatment at the Danish CF Center.

AU - Ciofu, O

AU - Giwercman, B

AU - Pedersen, S S

AU - Høiby, N

N1 - Keywords: Anti-Bacterial Agents; Carbenicillin; Ceftazidime; Ciprofloxacin; Cystic Fibrosis; Denmark; Drug Resistance, Microbial; Drug Therapy, Combination; Humans; Microbial Sensitivity Tests; Piperacillin; Pneumonia, Bacterial; Pseudomonas Infections; Pseudomonas aeruginosa; Tobramycin; beta-Lactamases

PY - 1994

Y1 - 1994

N2 - At the Danish CF Center patients with chronic Pseudomonas aeruginosa lung infection were treated 3-4 times a year (from 1976) with a 2-week intravenous antipseudomonal course which included preferentially an aminoglycoside and a beta-lactam antibiotic. We investigated the development of antibiotic resistance in P. aeruginosa strains isolated from Danish CF patients over a period of 18 years by testing the in vitro efficacy of carbenicillin, piperacillin, ceftazidime, tobramycin and ciprofloxacin against P. aeruginosa strains collected in 1973 (51 strains), 1980 (80 strains), 1985 (58 strains), and 1991 (100 strains). All the strains were screened and assayed semiquantitatively for beta-lactamase activity by use of nitrocefin. We found a significant (p < 0.005) increase in the MIC values of the P. aeruginosa strains against piperacillin and ceftazidime. However, no significant correlation was found between the MIC and the number of antipseudomonal courses of antibiotics. The proportion of resistant in vivo selected P. aeruginosa strains, presumed to be stably derepressed producers of chromosomal beta-lactamase, also increased significantly during the period studied. Our results confirm that the beta-lactamase production is an important mechanism of antibiotic resistance in P. aeruginosa.

AB - At the Danish CF Center patients with chronic Pseudomonas aeruginosa lung infection were treated 3-4 times a year (from 1976) with a 2-week intravenous antipseudomonal course which included preferentially an aminoglycoside and a beta-lactam antibiotic. We investigated the development of antibiotic resistance in P. aeruginosa strains isolated from Danish CF patients over a period of 18 years by testing the in vitro efficacy of carbenicillin, piperacillin, ceftazidime, tobramycin and ciprofloxacin against P. aeruginosa strains collected in 1973 (51 strains), 1980 (80 strains), 1985 (58 strains), and 1991 (100 strains). All the strains were screened and assayed semiquantitatively for beta-lactamase activity by use of nitrocefin. We found a significant (p < 0.005) increase in the MIC values of the P. aeruginosa strains against piperacillin and ceftazidime. However, no significant correlation was found between the MIC and the number of antipseudomonal courses of antibiotics. The proportion of resistant in vivo selected P. aeruginosa strains, presumed to be stably derepressed producers of chromosomal beta-lactamase, also increased significantly during the period studied. Our results confirm that the beta-lactamase production is an important mechanism of antibiotic resistance in P. aeruginosa.

M3 - Journal article

C2 - 7946270

SN - 0903-465X

VL - 102

SP - 674

EP - 680

JO - APMIS. Supplementum

JF - APMIS. Supplementum

IS - 9

ER -