CLINICAL AND BACTERIOLOGICAL SURVEY AFTER CHANGE IN AMINOGLYCOSIDE TREATMENT TO CONTROL AN EPIDEMIC OF ENTEROBACTER-CLOACAE

The effect of a change in the first line antibiotic treatment in a neo natal unit was studied. A total of 238 neonates (G1), admitted between 1 January and 31 July 1989, and treated with gentamicin, were compare d with 398 (G2) admitted between 1 August 1989 and 31 July 1990 who re ceived amikacin, in the combination of ampicillin plus an aminoglycosi de. This change was implemented in an attempt to prevent the spread of an epidemic strain of Enterobacter cloacae resistant to third generat ion cephalosporins and all aminoglycosides, except amikacin. The chang e in treatment had no effect on the incidence of nosocomial infections [19.7% (G1) vs. 16.3% (G2) RR = 1.21 (0.86-1.70)], but the proportion of patients with nosocomial infections caused by the E. cloacae decre ased (6.3% vs. 2.0% RR 3.14 CI 1.35-7.28). Certain trends in the bacte rial ecology emerged: E. aerogenes and Enterococci increased in G2. Th e proportion of gentamicin-resistant strains such as E. cloacae or Sta phylococci decreased and there was no increase in aminoglycoside-resis tant strains, except in Escherichia coli, in which resistance to amika cin rose from 0 to 3%. This study illustrates the influence of antimic robial therapy on the species and the resistance of strains isolated i n nosocomial infections. It also highlights the need for epidemiologic surveillance, and poses the question of how best to modify antibiotic policy.