Antibiotic sensitivity test. Comparative multicenter study of the gel diffusion and ATB methods

: The ATB method is a new method for antibiotic susceptibility testing. In a collaborative study, it was compared to a standard disc diffusion method. 23 strains were tested to determine reproducibility and 969 strains were used in the comparative study. Reproducibility of both methods is equivalent; differences due to strains were observed. Agreement between both methods is 87,9%, minor discrepancies are 8,7% and major discrepancies are 3,3%. Significant differences were found for carbenicillin and cefalotin and confirmed by MIC determination using the agar dilution method. Overall results show that the ATB method is reliable and comparable to disc diffusion for routine susceptibility testing.