The effect of Sub-Minimum Inhibitory Concentration (S-MIC) of ciprofloxacin & ampicillin on hemolysin activity of Escherichia coli

Sub-minimum inhibitory concentration (S - MIC) can induce changes in morphology, virulence factors and biochemical properties of bacterial pathogens. The goal of this study is to determine the Sub-MIC effect of ciprofloxacin and ampicillin on the haemotytic activity of E. coli.Two clinical isolates of E. coli with high heamolytic activity was selected. Changes in haemolytic activity of the isolates was assessed after exposing them to MIC and Sub-MIC of ciprofloxacin and ampicillin. Ciprofloxacin decreased haemolytic activity at 1/2, 1/4 and 1/8 Sub-Mic, whereas ampicillin showed no effect on haemolytic activity. We conclude that Sub-MIC concentrations of ciprofloxacin decreased the haemolytic activity of E. coli, wherease ampicillin had no such effect.