Antibiotic usage and resistance - trends in Estonian University Hospitals.

The use of antibiotics, type of infections and resistance of prevalent bacteria was surveyed in Tartu University hospitals. The data from two ICUs (1995 and 1998), surgical and internal medicine departments (1998) were compared. Overall antibiotic usage in the ICUs and in the hospital as a whole had increased. There was a significant increase in Gram-positive bacterial infections and a decrease in Gram-negative infections in the ICUs. At the same time, susceptibility to several antibiotics decreased in most of the prevalent Gram-negative aerobes in the ICUs (Acinetobacter spp., Pseudomonas spp., Klebsiella spp.). Exceptions to this were the greater susceptibility of Pseudomonas spp. to gentamicin and Acinetobacter spp. to imipenem. Some changes in the predominant bacterial populations did not correlate to changes in antibiotic use.