Nosocomial consequences of antibiotic usage.

In 1979, seven years after introduction of gentamicin into the greek market, resistance in Pseudomonas aeruginosa rose in Laiko General Hospital to an incidence of 55% of the isolates. Gentamicin then was the first line antibiotic. In 1983, three years after amikacin was brought onto the market and while it represented 3/5 of all aminoglycoside consumption, resistance against it in strains of Pseudomonas rose suddenly to 23%. However, amikacin prescription was not restricted and, in 1985, resistance rate, including all aminoglycosides and the 3rd generation cephalosporins, exceeded 50%. By analysing all available data, it was evident that: Urine predominates in the isolation of multiresistant strains, while in 1/2 of bacteraemias amikacin-resistant strains are implicated. The ICU is the most common source of isolation and similar strains are spread in all hospital wards. Multiresistant strains are virulent since they were incriminated for a 11% death rate. In 60% of amikacin resistant strains AAC (6') I was detected. Among multiresistant strains serotype O:12 predominated. From the hospital pharmacy data, it was evident that antibiotic consumption refers to greater than 60% of hospital admissions, and amikacin, netilmicin and newer cephalosporins are the first line antibiotics. It is evident that urgent changes are needed in the antibiotic policies in the Laiko General Hospital.