Antimicrobial Activity of Crude Extracts of 1solona Cauliflora Against Some Bacteria of Veterinary Importance

Abstract

In this work, the growth inhibiting activity of crude leaf extracts of I. cauliflora against animal bacterial pathogens E. coli, S. gallinarum, and S.aureus was compared to commercially available antibiotics cephalexin, trimethoprin, and gentamycin. In standard disk assays, I. cauliflora extracts caused zones of growth inhibition against all three strains tested. The extract was most effective against S. aureus, displaying inhibition zones of greater magnitude than the antibiotics tested.  The minimal   inhibitory   concentration   (MIC) fell   below 100 µg/ml for S. aureus, well within the effective clinical range for a therapeutic antimicrobial agent.   Similarly, the mininimal bactericidal concentration (MBC) for S. aureus was determined to be 31.25µg/ml, well below the LC50 of 72.44 µg/ml as determined by the Brine Shrimp test. Crude I. cauliflora leaf extracts also displayed moderate bactcriostatic activity against E. coli and S. gallinarum