Antimicrobial use and susceptibility rates in isolates from intensive careunit and other nosocomial inpatient and outpatient areas

Our objective was to evaluate the relation between antimicrobial use and su sceptibility in the intensive care unit (ICU) and non-ICU inpatient areas i n the Bolzano regional hospital. For the isolates of S. aureus, coagulase n egative staphylococci, Enterococcus sp., P. aeruginosa and E. coli we found a pattern of significant stepwise decrease in the frequency of antimicrobi al susceptibility to penicilloic beta -lactam antibiotics and first generat ion cephalosporins; the highest senitivity rates occurred among isolates fr om outpatients, followed in decreasing order by rates among isolates from n on-ICU inpatients and from ICU-patients; the rate of use of this group of a ntimicrobial agents was relatively high in the intensive care unit (13,1%). For P. aeruginosa we observed significantly lower susceptibility-rates to second, third and fourth generation cephalosporins, carbapenems and monobac tams for non-ICU inpatient areas than for outpatient or ICU areas; this par alleled with the low use of this group of agents in the ICU area (4,9%). Al so, for P. aeruginosa the prevalence of susceptibility to ciprofloxacin and norfloxacin in inpatient areas was lower than in the outpatient or ICU-are as; the rate of quinolone-use was relatively low in the ICU area (4,2%).