Cloning and Expression of Novel Aminoglycoside Phosphotransferase Genes from Campylobacter and Their Role in the Resistance to Six Aminoglycosides

Abstract

ABSTRACT Nine aph genes, including aph(2″)-Ib , aph(2″)-Ic , aph(2″)-Ig , aph(2″)-If , aph(2″)-If1 , aph(2″)-If3 , aph(2″)-Ih , aac(6′)-Ie – aph(2″)-Ia , and aac(6′)-Ie – aph(2″)-If2 , were previously identified in Campylobacter . To measure the contribution of these alleles to aminoglycoside resistance, we cloned nine genes into the pBluescript and expressed them in Escherichia coli DH5α. The nine aph expressed in E. coli showed various levels of resistance to gentamicin, kanamycin, and tobramycin. Three genes, aac(6″)-Ie – aph(2″)-Ia , aph2″-If1 , and aph2″-Ig , showed increased MICs to amikacin, and five aph genes were transferrable.