ABSTRACT

The objective of this study was to screen some commonly used antibiotics contained in antibiotic discs made by different manufacturers (both local and foreign) for their efficacy against some clinical bacterial isolates. Samples of urine, HVS and wound swab were collected from Federal Medical Center Umuahia. The organisms isolated were pure cultures of Staphylococcus aureus, Esherichia coli and Pseudomonas aeruginosa. The disc susceptibility test was used to screen the antibiotics used which includes augumentin, erythromycin, gentamicin and ciprofloxacin. It was observed that ciproflox showed the highest activity against all the organisms used. The zones of inhibition were 59mm and 31mm (for local and foreign discs respectively) against Staphylococcus aureus, 44mm and 28mm (local and foreign discs) against Escherichia coli and 48 and 18mm (local and foreign discs) against Pseudomonas aeruginosa. Augumentin showed the least activity and was effective only against Staphylococcus aureus with zone of inhibition of 27mm and Pseudomonas aeruginosa 37mm (for local discs) but resistant to the foreign discs against the same organisms. Augumentin was not effective against E. coli for both local and foreign antibiotics. Pseudomonas showed the least susceptibility when compared with other organisms, showing the least zones of inhibition against the same antibiotics used. The study revealed that the antibiotic contained in locally made discs appear to be more effective, showing higher zones of inhibition when compared to foreign discs. However, the difference in the zones of inhibition of gentamicin, erythromycin, augumentin and ciproflox contained in locally produced commercial antibiotic discs as against ones contained in antibiotic discs produced commercially by a foreign company were statistically significant (p<0.05). In as much as this study has demonstrated that foreign discs appear to be less effective against agents of infection, the local discs with highest activities are hereby recommended in therapy.