Abstract

A total of ten clinical bacterial isolates comprising five isolates of Escherichia coli isolated from surgical wound patients at the Federal Medical Centre, Abakaliki and five isolates ofStaphylococcus aureus isolated from the wound sites of burnt patients at the University of Nigeria Teaching Hospital, Enugu were evaluated for their susceptibility to colloidal silver at 5 and 20 ppm using agar dilution method and the killing rate technique. Also, interaction studies between colloidal silver and some conventional antibiotics were carried out against the clinical isolates of Escherichia coli and S. aureus using disc diffusion technique. The result of the study shows that the test organisms were sensitive to the colloidal silver at both concentrations and also to some of the antibiotics in the paper disc. The killing rate studies revealed that the colloidal silver is highly bactericidal against the test isolates at both concentrations. The drug interaction study showed no antagonism, indicating that concomitant use of colloidal silver with these antibiotics may not affect the therapeutic efficacy of either of these agents.

Key words: Antibacterial, colloidal silver, clinical bacteria isolates, antibiotic discs, killing rate, wound infections.