Comparative antibacterial activity of a novel semisynthetic antibiotic: etimicin sulphate and other aminoglycosides

Etimicin is a novel fourth generation semisynthetic aminoglycoside. It has good antimicrobial activity against both gram-positive and gram-negative bacterial infections and also against aminoglycoside resistant strains. In the present study, in vitro antibacterial activity of etimicin was determined by minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and time kill curve tests against type strains and 407 clinical isolates (obtained in a surveillance study), in comparison to other aminoglycosides. Test results revealed that etimicin has potential antimicrobial activity and MIC, MBC values for etimicin were low compared to other aminoglycosides. In MBC test etimicin has exhibited potential bactericidal effect ranging from 0.25 to 2 mg/L. The time kill-curve study further demonstrated the rapid, concentration dependent killing and comparative study showed etimicin to exhibit long and effective bactericidal activity over amikacin. The interesting fact is that most of the tested aminoglycoside resistant clinical isolates were susceptible to etimicin. In view of its potent in vitro antibacterial activity and efficacy profiles, it can be concluded that etimicin can be a potent injectable agent for the treatment of severe bacterial infections.