TICARCILLIN-CLAVULANIC ACID - DETERMINATION OF MINIMAL INHIBITORY CONCENTRATIONS AGAINST BACTERIAL STRAINS ISOLATED FROM PATIENTS IN INTENSIVE-CARE UNITS - COMPARISON WITH OTHER AGENTS

A total of 303 bacterial strains isolated from bronchoaspirates of Int ensive Care Unit (ICU) patients, collected through June and December 1 993, were tested for susceptibility to ticarcillin/clavulanic acid, im ipenem, amikacin, ceftazidime, ciprofloxacin and piperacillin. The min imal inhibitory concentration (MIG) for each antibiotic was determined according to the NCCLS, by means of serial dilution on microplates. T he isolates, 80.8% of which were beta-lactamase producing strains, bel onged to Pseudomonas aeruginosa (79 strains), Pseudomonas fluorescens (8 strains), Xanthomonas maltophilia (25 strains), Escherichia roll (1 6 strains), Klebsiella-Enterobacter-Serratia (KES) (62 strains), Prote us spp. (15 strains), Acinetobacter spp. (22 strains), Moraxella spp. (15 strains), Bacteroides catarrhalis (8 strains), Haemophilus spp. (1 1 strains), Straphylococcus aureus (32 strains), Enterococcus faecalis (10 strains). The highest rate of susceptibility to ticarcillin/clavu lanic acid (100%) was detected among E. faecalis (MIG 2-16 mu g/ml), B . catarrhalis (MIG 1-4 mu g/ml) and Hemophilus spp. (MIG 1-4 mu g/ml). Among the non-fermenting microorganisms ticarcillin/-clavulanic acid showed good activity toward P. aeruginosa and P. fluorescens (86% and 75% respectively). It was also very active against X. maltophilia with a susceptibility of 96%. Susceptibility to the other antibiotics test ed was within the range of 16% and 28%.