A comparative study on the antibacterial activity of Mangifera indica (mango) and Psidium Guajava (guava) leaves extract against Escherichia coli

Date of Completion


Document Type

Research Project

Degree Name

Grade 12


Antibacterial agents, Escherichia Coli, Mangifera, Psidium, Plant Extract


Escherichia coli are known to be gastrointestinal pathogens and particular strains may cause illnesses like diarrhea, abdominal pain, fever and occasional vomiting. This study utilizes Mangifera Indica (mango and Psidium guajava (guava) leaves extract to compare which among two of the most common leaves in the Philippines have better antibacterial activity against E. coli. In conducting the experiment, the leaves from each plant were separately dried, powdered, macerated in ethanol, subjected to solvent evaporation, and diluted with type 1 water to create 100mg/ml concentration of treatments. The Mangifera indica dn Psidium guajava leaves extract, along with Norfloxacin (positive control) and Ethanol (negative control) were inoculated to MHA plate streaked with E. coli. After 24 hours of incubation, the results showed taht Mangifera indica had a higher zone of inhibition mean (13.83 mm) compared to Psidium guajava (6.5mm), with p-value of 0.003 from t-test analysis indicating a significant difference between them. ANOVA from the zone of inhibition means of the plant extracts and Norfloxacin showed a p (same) that is greatly lower than the standard P (same) of 0.05, implying the despite the significantly grater antibacterial activity of Mangifera indica leaf extract to Psidium guajava leaf extract, its antibacterial activity to E. coli still isn't as effective as the antibacterial activity of Norfloxacin.

First Advisor

Myra Michelle M. Mojica

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