Determination of Antibacterial Activity of Psidium guajava Leaf Extract against Bacteria Isolated from Mobile Phones of Umaru Musa Yar’adua University, Katsina Community

Abstract

Mobile phones are increasingly becoming indispensable accessories for professional and social daily life, but their constant handling and usage in various environmental conditions make them potential fomites. This study evaluated the antibacterial activity of Psidium guajava leaf extract against bacteria isolated from mobile phones within the Umar Musa Yar’adua University, Katsina community. A total of sixty (60) mobile phones were randomly swabbed, consisting of twenty (20) each from hawkers, students, and staff of the University community. These samples served as candidates for the isolation of bacterial contaminants using standard protocols. Variable concentrations (500 mg/ml, 300 mg/ml, and 100 mg/ml) of the aqueous extract of Psidium guajava were prepared and tested against the bacterial isolates using the agar well diffusion method. Preliminary phytochemical screening revealed the presence of flavonoids, cardiac glycosides, saponins, tannins, and terpenoids. The bacterial contaminants isolated and identified from the mobile phones included Staphylococcus aureus (39.6%), Escherichia coli (29.7%), Klebsiella sp. (18.8%), Proteus sp. (8.3%), and Pseudomonas aeruginosa (4.2%). The aqueous leaf extract of Psidium guajava displayed promising antibacterial activity at 500 mg/ml against all the isolates, with average zones of inhibition measuring 25.0 mm for S. aureus, Proteus sp., and P. aeruginosa, and 24.0 mm and 6.0 mm for E. coli and Klebsiella sp., respectively. The use of Psidium guajava leaf extract as a candidate for the production of antibacterial agents to disinfect mobile handsets is suggested.