[Evaluation of the antibiotic sensitivity of Pseudomonas sp. using the API-ATB-PSE system. Comparison with diffusion...

In vitro activity of twelve antibiotics (ticarcillin, mezlocillin, azlocillin, piperacillin, cefoperazone, cefsulodin, ceftazidime, gentamicin, netilmicin, pefloxacin and ciprofloxacin) was determined by measuring minimum inhibitory concentrations (MICs) using agar dilution according to WHO recommendations, agar diffusion and the API-ATB-PSE system. One-hundred and forty-two Pseudomonas strains were studied. Five species of Pseudomonas were represented, i.e. aeruginosa, maltophilia, cepacia, stutzeri and paucimobilis. Isolates came from two Paris hospitals. Percentages of total agreement, minor discrepancies and major discrepancies between the results obtained with the API-ATB-PSE method and those recorded with the reference methods were determined. After checking the discordant strains, the results are discussed in order to evaluate the reliability of the ATB method for antibiotic susceptibility testing with Pseudomonas sp.