The chemical structure of apramycin differs somewhat from that of the typical aminoglycosides but is similar enough to be included in this class. The structure of spectinomycin is unusual, but it is fairly comparable to other aminocyclitols with regard to its mechanism of action and antibacterial spectrum. Apramycin is used to control gram-negative infections, particularly Escherichia coli and salmonellae in calves and piglets. It also is active against Proteus, Klebsiella, Brachy-spira, and Mycoplasma spp. There is little crossresistance within the aminoglycosides