Antistaphylococcal effects of alcoholic extracts of Tetrapleura tetraptera (Schum and Thonn.) (Taub.) against multidrug methicillin resistant Staphylococcus aureus

Abstract

Background: Staphylococcus aureus is a pathogen causing life-threatening hospital and community-acquired infections with high morbidity and mortality rates requiring constant vigilance. Aim: This study aimed at investigating the antistaphylococcal effects of Tetrapleura tetraptera against different strains of multidrug methicillin resistant S. aureus (MRSA) to indicate the need for its use in ethnomedicine in addition to its fruits being used in traditional medicine. Methods: In this study, the susceptibilities of S. aureus were investigated using multi-disc antibiotics and extracts of T. tetraptera by agar diffusion and macrobroth dilution methods. Settings: While attention has been focused on the fruits of this plant, it is necessary to investigate the pharmacological importance of its stem bark. Results: The antibiogram showed that 70% of the isolates were multidrug resistant. Nitrofurantoin and gentamicin antibiotics were the most effective whilst amoxicillin and augumentin were the least effective. The susceptibility of the isolates was concentration dependent as inhibition zones decreased with decrease in the concentrations of each of the extracts. The minimum inhibitory concentrations (MICs) of acetone extract ranged between 0.019 mg/mL and 20 mg/mL whilst the minimum bactericidal concentrations (MBCs) ranged between 0.3125 mg/mL and 20 mg/mL. The MICs of the methanol extract ranged between 0.039 mg/mL and 5.0 mg/mL whilst the MBCs ranged between 0.3125 mg/mL and 10 mg/mL. Both extracts were more bactericidal than being bacteriostatic against all the isolates. The methanol extract was more active than the acetone extract as indicated by the varied inhibition zones and MICs obtained from the different extracts. Conclusion: This study revealed the great therapeutic potentials of T. tetraptera and validated its use in ethnomedicine and would be effective in the treatment of multidrug and MRSA infections.

Keywords

• antistaphylococcal activities
• macrobroth dilution assay
• methicillin resistant bacteria
• nosocomial infections
• pharmacological activity
• tetrapleura tetraptera