Comparison of the E test and agar dilution method for antimicrobial suceptibility testing of Helicobacter pylori.
A multicentre study was carried out in order to validate the E test in comparison with the reference agar dilution method for testing the susceptibility of Helicobacter pylori to amoxicillin, clarithromycin, and metronidazole. Ten clinical isolates and one control collection isolate ( Helicobacter pylori ATCC 43504) were tested blindly at four centres according to a uniform methodology. The E test showed excellent intra- and inter-laboratory correlations with the agar dilution method for amoxicillin and clarithromycin (>98% agreement within 2 log(2) dilution steps). For metronidazole, however, the E test revealed significantly higher minimum inhibitory concentration values (>2 log(2)) against 5 of the 10 Helicobacter pylori strains tested. Overall, neither method was found reliable for testing the susceptibility of Helicobacter pylori to metronidazole, since both tended to lack reproducibility.
Glupczynski
Y
Y
Laboratoire de bactériologie, Cliniques Universitaires U.C.L. de Mont-Godinne, 1 Avenue Dr. Therasse, 5530 Yvoir, Belgium. yglupczynski@compuserve.com
Broutet
N
N
Cantagrel
A
A
Andersen
L P
LP
Alarcon
T
T
López-Brea
M
M
Mégraud
F
F
D000658:Amoxicillin / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017291:Clarithromycin / Q000494:pharmacology; D024881:Drug Resistance, Bacterial; D016481:Helicobacter Infections / Q000382:microbiology; D016480:Helicobacter pylori / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification / Q000502:physiology; D006801:Humans; D008795:Metronidazole / Q000494:pharmacology; D008826:Microbial Sensitivity Tests / Q000379:methods*; D015203:Reproducibility of Results
D000900:Anti-Bacterial Agents; D008795:Metronidazole; D000658:Amoxicillin; D017291:Clarithromycin