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

Mobile phones are increasingly becoming one of the indispensable accessories of professional and social daily life, although constant handling and usage in various environmental conditions makes it fomite. Thus, antibacterial activity of Psidium guajava leaf extract was evaluated against bacteria isolated from mobile phones within Umar Musa Yar’adua University, Katsina community. A total of sixty (60) mobile phones were randomly swabbed, twenty (20) each, from hawkers, students, and staff of the University community. These were used as candidates for isolation of bacterial contaminants using standard protocols. Variable concentrations (500mg/ml, 300mg/ml and 100mg/ml) of aqueous extract of the Psidium guajava were prepared and tested against mobile phones bacterial isolates using agar well diffusion method. Preliminary phytochemical screening revealed the presence of flavonoids, cardiac glycosides, saponins, tannins and terpenoids. Staphylococcus aureus (39.6%), Escherichia coli (29.7%), Klebsiella sp. (18.8%), Proteus sp. (8.3%) and Pseudomonas aeruginosa (4.2%) were the bacterial contaminants isolated and identified from the mobile phones. Aqueous leaf extract of the plant displayed promising antibacterial activity at 500mg/ml against all the isolates, with average zones of inhibition of 25.0 mm for S. aureus, Proteus sp., P. aeroginosa and 24mm, 6.0mm for E. coli and Klebsiella sp. respectively. The use of Psidium guajava leaf extract as candidate for production of antibacterial agent which can be used to disinfect mobile handsets is suggested. Keywords: Mobile phones, contaminants, Antibacterial activity, Psidium guajava, antibacterial hand wash