TY - JOUR
T1 - Evaluation of the E test for the assessment of synergy of antibiotic combinations against multiresistant Pseudomonas aeruginosa isolates from cystic fibrosis patients
AU - Balke, B
AU - Hogardt, M
AU - Schmoldt, S
AU - Hoy, L
AU - Weissbrodt, H
AU - Häussler, S
PY - 2006/1
Y1 - 2006/1
N2 - The determination of synergistic effects of antimicrobial drug combinations can lead to improved therapeutic options in the antibiotic treatment of cystic fibrosis patients who are chronically infected with multiresistant Pseudomonas aeruginosa isolates. The aim of this study was to evaluate the performance of the E test versus the standard agar dilution checkerboard susceptibility test in the assessment of synergy and, in addition, to determine the activity of two antimicrobial combinations against 163 multiresistant P. aeruginosa isolates from cystic fibrosis patients. The agreement between the checkerboard method and the E test was excellent (>90%) for nonmucoid as well as mucoid isolates from cystic fibrosis patients. The rate of synergy was higher for the antibiotic combination of ceftazidime and tobramycin (28.8% of the cystic fibrosis strains) than for the combination of meropenem and tobramycin (19.0%). However, the probability of synergy for the second antibiotic combination increased significantly when the synergy of the first antibiotic combination had already been demonstrated (Fischer's exact test, p=0.049). The results show that the E test is a valuable and practical method for routine microbiological diagnostics and can aid in the selection of improved antibiotic options in the treatment of cystic fibrosis patients chronically infected with P. aeruginosa.
AB - The determination of synergistic effects of antimicrobial drug combinations can lead to improved therapeutic options in the antibiotic treatment of cystic fibrosis patients who are chronically infected with multiresistant Pseudomonas aeruginosa isolates. The aim of this study was to evaluate the performance of the E test versus the standard agar dilution checkerboard susceptibility test in the assessment of synergy and, in addition, to determine the activity of two antimicrobial combinations against 163 multiresistant P. aeruginosa isolates from cystic fibrosis patients. The agreement between the checkerboard method and the E test was excellent (>90%) for nonmucoid as well as mucoid isolates from cystic fibrosis patients. The rate of synergy was higher for the antibiotic combination of ceftazidime and tobramycin (28.8% of the cystic fibrosis strains) than for the combination of meropenem and tobramycin (19.0%). However, the probability of synergy for the second antibiotic combination increased significantly when the synergy of the first antibiotic combination had already been demonstrated (Fischer's exact test, p=0.049). The results show that the E test is a valuable and practical method for routine microbiological diagnostics and can aid in the selection of improved antibiotic options in the treatment of cystic fibrosis patients chronically infected with P. aeruginosa.
KW - Anti-Bacterial Agents/pharmacology
KW - Ceftazidime/pharmacology
KW - Cystic Fibrosis/complications
KW - Drug Resistance, Multiple/drug effects
KW - Drug Synergism
KW - Drug Therapy, Combination
KW - Humans
KW - Meropenem
KW - Microbial Sensitivity Tests/methods
KW - Pseudomonas Infections/complications
KW - Pseudomonas aeruginosa/drug effects
KW - Reproducibility of Results
KW - Thienamycins/pharmacology
KW - Tobramycin/pharmacology
U2 - 10.1007/s10096-005-0076-9
DO - 10.1007/s10096-005-0076-9
M3 - Journal article
C2 - 16402226
SN - 0934-9723
VL - 25
SP - 25
EP - 30
JO - European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology
JF - European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology
IS - 1
ER -