[Inactivation of free and liposome-encapsulated aminoglycosides by enzymes of resistant strains of bacteria].

Liposome-encapsulated gentamicin, sisomicin, paromomycin, amikacin, dibekacin and some other aminoglycoside antibiotics were prepared by the method of detergent dialysis. The entrapment level was higher with respect to paromomycin, gentamicin and sisomicin. After a 1-hour incubation of the liposome-encapsulated paromomycin in the presence of a cell-free preparation of 3'-1-phosphotransferase from Escherichia coli there was observed no inactivation of the antibiotic. Free paromomycin incubated under the same conditions in the presence of the enzyme was inactivated by 50 per cent. After a 3-hour incubation of paromomycin in the presence of 3"-1-phosphotransferase the antibiotic activity in the incubation mixture was not detected. The liposome-encapsulated paromomycin preserved about 50 per cent of the activity after its 18-hour incubation in the presence of the enzyme. Inactivation of gentamicin by a cell-free preparation of 2"-adenylyltransferase (Salmonella oranienburg 1376) was also markedly lowered when it was used encapsulated in liposomes.