[Bacterial resistance to aminoglycoside antibiotics]

Aminoglycoside antibiotics, such as gentamicin, netilmicin, tobramycin, amikacin, may be inactivated by resistant bacteria producing three types of enzymes: O-nucleotidyltransferases, O-phosphotransferases and N-acetyltransferases. Mechanisms of aminoglycoside resistance were analyzed in clinical isolates of gram-negative bacteria from several regions of Czecho-Slovakia and compared with the use of aminoglycosides. Production of acetyltransferases (AAC) and nucleotidyltransferases (ANT) was observed in 84% of bacterial isolates. The majority of bacterial strains studied produced the AAC/3/enzyme (62%). Due to dissemination of plasmids coding for the AAC/3/enzyme, the majority of Czecho-Slovak gentamicin-resistant strains was also tobramycin resistant (93%) and netilmicin resistant (68%). Amikacin remains the most effective aminoglycoside antibiotic against multiresistant bacterial strains.