[In vitro sensitivity at 18 antibiotics of 192 strains of Pseudomonas aeruginosa isolated at Garches Hospital].

The in vitro activity of 18 antibiotic (beta-lactam agents, quinolones and aminoglycoside has been evaluated against 192 clinical isolates of Pseudomonas aeruginosa. Minimal inhibitor concentrations (MICs) were determined by the agar dilution technique. The 50% and 90% MICs were respectively: ticarcillin (32/greater than 1 024), azlocillin (16/512), piperacillin (8/512), cefsulodin (4/128), ceftazidime (2/8), aztreonam (4/16), imipenem (2/4), nalidixic acid (128/256), pefloxacin (1/8), norfloxacin (1/8), ofloxacin (2/8), ciprofloxacin (0.25/2), gentamicin (8/256), sisomicin (4/256), tobramycin (2/128) dibekacin (4/256), netilmicin (16/256), amikacin (8/16). The sensitivity to beta-lactam agents and to quinolones was usual. Resistance to aminoglycosides was frequently observed (59%): 35.7% of the resistant isolates were resistant to gentamicin-sisomicin-tobramycin-dibekacin-netilmicin, 30% to netilmicin alone, 17.8% to gentamicin-sisomicin-tobramycin-dibekacin-netilmicin-amikacin, 7% to gentamicin-netilmicin, 5.3% to gentamicin-sisomicin-tobramycin-dibekacin; we did not find any P. aeruginosa resistant only to gentamicin or gentamicin-sisomicin.