Journal of International Research in Medical and Pharmaceutical Sciences

The use of concentrations of silver nitrate (a chemical agent) to inhibit the growth of selected bacterial organisms in vitro is the focus of this work. Antibiotic susceptibility testing was carried out on the selected bacterial organisms by agar disc diffusion method. Prepared standard dilutions of silver nitrate were tested on the same typed bacterial organisms by agar well diffusion technique. Measured zones of inhibition before and after chemical treatment were statistically paired by paired T-test for significant differences at 95% confidence interval (P˂0.05) and 99% confidence interval (P˂0.01). Antimicrobial time activity of AgNO₃ dilution that induced significant difference in clearance or inhibition zone was carried out at 15 mins, 30 mins, 45 mins,             60 mins and 75 mins at both confidence intervals. Nitrofurantoin (14.8±4.7 mm) and ofloxacin (13.4±5.1 mm) recorded the highest zones of inhibition cumulatively. Silver nitrate dilution of 200 ug/ml induced 23.5±1.2 mm zone of inhibition and 100% sensitivity by all tested organisms. Other dilutions recorded reduced sensitivity. Only 200 ug/ml AgNO₃ concentration recorded significant mean±standard error zone of inhibition (P˂0.05) and (P˂0.01) as paired with zones of inhibition recorded by cefuroxime and ciprofloxacin. In terms of effect of incubation time, 60 mins and 75 mins recorded zero survival of viable cells of Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus and Aeromonas hydrophila. The therapeutic potential of 200 ug/ml AgNO₃ concentration or dilution in synergistic combination with cefuroxime and/or ciprofloxacin in treatment of local and perhaps, systemic diseases is suggested.