Resistance: aminoglycoside-modifying enzymes
years antibiotic main enzymes
1960’s kanamycins 3’-OH and 4’-OH *
1970’s gentamicin 3-NH2, 2’-NH2, 2”-OH
1990’s several AG’s combinations **...
2000’s isepamicin ?? (3’-OH and 4’-OH) (back to the future …)
** more than 20 different phenotypes and 60 different genotypes...