In Vitro Antimicrobial Activity of Phyllanthus urinaria (Linnaeus, Phyllanthaceae) Leaves against Staphylococcus aureus and Pseudomonas aeruginosa Isolated from Wounds

The emergence and spread of antibiotic resistance have been on the increase, and as such there is a need for new and safer antimicrobials. Commonly used medicinal plants found in surrounding environments and communities can be used as medicines to treat infections. This research is aimed on exploring the antimicrobial properties of the Phyllanthus urinaria plant against selected bacterial pathogens, Staphylococcus aureus and Pseudomonas aeruginosa found in human wounds. The plant extracts were obtained by boiling, soaking and decoctioning the plant leaves. These extracts were subjected to a series of tests for their antimicrobial and active components. The antimicrobial assay was carried out by disc and agar-well diffusion methods. The results indicated that the extract exhibited antimicrobial properties. The highest and only potential was observed in the boiled extract against S. aureus with zones of inhibition at 6mm for disc diffusion method and 5mm for agar-well diffusion method at 100mg/mL and 3mm for 25mg/mL and Pseudomonas aeruginosa showed complete resistance of the plant extract. The mean efficacy of the extract showed 23.0% and 35.5% in comparison to Chloramphenicol in the agar-well diffusion method and disc diffusion method, respectively. A statistical test was carried out using the one-way ANOVA method, to show the statistically significant differences between the extracts, bacterial isolates, and also zones of inhibition. The results showed that in both the disc and agar-well diffusion methods, p-value was 0.0584; hence there were no statistically significant differences in the effects of the plant extracts on the bacterial isolates. This experiment confirmed the efficacy of the plant extract as a natural potential antimicrobial against Staphylococcus aureus.