Confronto fra l’Attività di Isepamicina, un Nuovo Aminoglicoside, e di Altri Antibiotici su Patogeni Nosocomiali Recentemente Isolati in Italia

Summary

Amikacin has been extensively used, often in combination with a β-lactam, in the empirical therapy of severe nosocomial infections. In certain geographical areas, however, the emergence of resistance in hospital pathogens has reduced the efficacy of this antibacterial. Isepamicin, a recently developed aminoglycoside that is highly stable in the presence of inactivating enzymes, is thus more potent in vitro than amikacin and may have the potential to overcome the development of aminoglycoside resistance. In order to confirm this assumption, a multicentre survey involving 16 laboratories was conducted in Italy during 1995. Disk diffusion and minimum inhibitory concentration determination (limited to isepamicin, amikacin, ceftazidime, ciprofloxacin and meropenem for Pseudomonas aeruginosa strains) were used to test 2578 nosocomial pathogens against isepamicin, amikacin, ceftazidime, ciprofloxacin, gentamicin, tobramicin, imipenem and meropenem. According to the suggested NCCLS breakpoints, isepamicin was more active (97%) than amikacin (90%) against Enterobacteriaceae. All other aminoglycosides were far less potent. Imipenem was the only drug comparable to isepamicin. Netilmicin was the best antimicrobial agent against S. aureus (90% of the strains susceptible), with isepamicin as active as amikacin. Pseudomonas demonstrated a high level of resistance (> 25%) to all the antibiotics tested, with isepamicin being as effective as amikacin and ciprofloxacin. Acinetobacter spp. were particularly susceptible to imipenem. Isepamicin and amikacin showed a potency largely exceeding that of ciprofloxacin and ceftazidime. Given its broad spectrum of bactericidal activity and its ability to overcome amikacin resistance, especially in Enterobacteriaceae, isepamicin represents a potentially useful drug in the empirical therapy of severe nosocomial infections.