[Enzymatic mechanisms of resistance to aminoglycoside antibiotics in gram negative bacilli from Chilean hospitals].

The presence of aminoglycoside modifying enzymes (AMEs) has been investigated, by an agar diffusion method, in 344 strains of aminoglycoside-resistant Gram negative bacilli isolated in different Chilean hospitals. Most of the strains exhibited a combination of enzymatic mechanism of resistance, but two acetylating (AAC(3)II and AAC(6')I) and one phosphorylating (APH(3')I) enzymes were the main mechanism detected in the strains. A significant increase in the frequency of strains producing AAC(6')I, possible due to wide use of amikacin, has been found when results were compared with those of a report published in 1985.