A conjugate having the general formula I: A-X-D-Y-B Formula I wherein: A is a non-ribosomal-active antimicrobial agent moiety, said non-ribosomal-active antimicrobial agent being a quinolone-based antimicrobial agent selected from the group consisting of a fluoroquinolone, ciprofloxacin (Cipro, Ciprobay, Ciproxin), balofloxacin (Baloxin), cinoxacin (Cinobac), clinafloxacin, danofloxacin (Advocin, Advocid), delafloxacin, difloxacin (Dicural, Vetequinon), enoxacin (Enroxil, Penetrex), enrofloxacin (Baytril), fleroxacin (Megalone, Roquinol), flumequine (Flubactin), garenoxacin (Geninax), gatifloxacin (Tequin, Zymar), gemifloxacin (Factive), grepafloxacin (Raxar), ibafloxacin (Ibaflin), levofloxacin (Cravit, Levaquin), lomefloxacin (Maxaquin), marbofloxacin (Marbocyl, Zenequin), moxifloxacin (Avelox, Vigamox), nadifloxacin (Acuatim, Nadoxin, Nadixa), nalidixic acid (NegGam, Wintomylon), norfloxacin (Lexinor, Noroxin, Quinabic, Janacin), ofloxacin (Floxin, Oxaldin, Tarivid), orbifloxacin (Orbax, Victas), oxolinic acid (Uroxin), pazufloxacin (Pasil, Pazucross), pefloxacin (Peflacine), pipemidic acid (Dolcol), piromidic acid (Panacid), prulifloxacin (Quisnon), rosoxacin (Eradacil), rufloxacin (Uroflox), sarafloxacin (Floxasol, Saraflox, Sarafin), sitafloxacin (Gracevit), sparfloxacin (Zagam), temafloxacin (Omniflox), tosufloxacin (Ozex, Tosacin) and trovafloxacin (Trovan); B is an aminoglycoside-based antimicrobial agent moiety, said aminoglycoside being a 4,6-disubstituted-2-deoxystreptamine type aminoglycoside; X is a first spacer moiety, covalently bound to A, or absent; Y is a second spacer moiety, covalently bound to B, or absent; and D is a linking moiety having the general formula II: whereas each of the wiggled lines denote covalent bond to either A-X- or B-Y-, and R 1 is selected from the group consisting of hydrogen, alkyl, cycloalkyl and alkenyl. A is a non-ribosomal-active antimicrobial agent moiety, said non-ribosomal-active antimicrobial agent being a quinolone-based antimicrobial agent selected from the group consisting of a fluoroquinolone, ciprofloxacin (Cipro, Ciprobay, Ciproxin), balofloxacin (Baloxin), cinoxacin (Cinobac), clinafloxacin, danofloxacin (Advocin, Advocid), delafloxacin, difloxacin (Dicural, Vetequinon), enoxacin (Enroxil, Penetrex), enrofloxacin (Baytril), fleroxacin (Megalone, Roquinol), flumequine (Flubactin), garenoxacin (Geninax), gatifloxacin (Tequin, Zymar), gemifloxacin (Factive), grepafloxacin (Raxar), ibafloxacin (Ibaflin), levofloxacin (Cravit, Levaquin), lomefloxacin (Maxaquin), marbofloxacin (Marbocyl, Zenequin), moxifloxacin (Avelox, Vigamox), nadifloxacin (Acuatim, Nadoxin, Nadixa), nalidixic acid (NegGam, Wintomylon), norfloxacin (Lexinor, Noroxin, Quinabic, Janacin), ofloxacin (Floxin, Oxaldin, Tarivid), orbifloxacin (Orbax, Victas), oxolinic acid (Uroxin), pazufloxacin (Pasil, Pazucross), pefloxacin (Peflacine), pipemidic acid (Dolcol), piromidic acid (Panacid), prulifloxacin (Quisnon), rosoxacin (Eradacil), rufloxacin (Uroflox), sarafloxacin (Floxasol, Saraflox, Sarafin), sitafloxacin (Gracevit), sparfloxacin (Zagam), temafloxacin (Omniflox), tosufloxacin (Ozex, Tosacin) and trovafloxacin (Trovan); B is an aminoglycoside-based antimicrobial agent moiety, said aminoglycoside being a 4,6-disubstituted-2-deoxystreptamine type aminoglycoside; X is a first spacer moiety, covalently bound to A, or absent; Y is a second spacer moiety, covalently bound to B, or absent; and D is a linking moiety having the general formula II: