Anti-bacterial activity of mango (Mangifera indica) leaf extracts against Pseudomonas aeruginosa and Staphylococcus aureus. A cross-sectional study.

Abstract

Background. This study evaluated the antibacterial activity of M. indica leaf extracts against clinical isolates of Staphylococcus aureus and Pseudomonas aeruginosa. Methodology. Mature M. indica leaves were collected from the University of Kisubi compound, authenticated, dried, pulverized, and extracted by maceration in a 1:1 ethanol-acetone solvent mixture (20% w/v). Phytochemical screening was performed using standard qualitative tests. Antibacterial activity was assessed by the agar well diffusion method. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by broth microdilution with resazurin dye, and MBC/MIC ratios were calculated to classify activity as bactericidal (≤4) or bacteriostatic (>4). Results. Phytochemical screening confirmed the presence of flavonoids, tannins, and mangiferin in the extract. The extract exhibited antibacterial activity against both test organisms, with significantly greater activity against Staphylococcus aureus (mean inhibition zone = 16.93 ± 1.83 mm) than Pseudomonas aeruginosa (10.53 ± 3.07 mm) (p < 0.001). The predominant MIC values were 1/128 for Staphylococcus aureus and 1/16 for Pseudomonas aeruginosa. Bactericidal activity was observed in all Staphylococcus aureus isolates and in 93.3% of Pseudomonas aeruginosa isolates. Conclusion. Mangifera indica leaf ethanol-acetone extract possesses significant antibacterial activity, particularly against S. aureus, and predominantly bactericidal effects against both tested pathogens. Recommendation. Further bioassay-guided fractionation is recommended to isolate and characterize the active compounds, followed by in vivo toxicity, pharmacokinetic, and efficacy studies to evaluate clinical potential as an alternative antibacterial agent.