ABSTRACT

A total of 36 samples were collected from different parts (keyboard, touchpad/mouse and screen) of both public and personal computers. Total heterotrophic counts ranged from 0.46×108 - 2.00×108cfu/ml in screen, 0.64×108 - 2.53×108cfu/ml in keyboard and 0.50×108 - 2.32×108cfu/ml in touchpad samples. Coliform counts ranged from 0.17×108 - 1.87×108cfu/ml in screen, 0.46×108 - 2.10×108cfu/ml in keyboard and 0.28×108 - 1.89×108cfu/ml in touchpad samples. Staphylococcal counts ranged from 0.04×106 - 0.14×106cfu/ml in screen, 0.09×106 - 0.41×106cfu/ml in keyboard and 0.03×106 - 0.32×106cfu/ml in touchpad samples. Fungal counts ranged from 0.03×106 - 0.18×106cfu/ml in screen, 0.12×106 - 0.32×106cfu/ml in keyboard and 0.04×106 - 0.25×106cfu/ml in touchpad samples. The microbial counts conducted showed that the public computers had more contamination levels. Seven bacterial species (Staphylococcus sp., Streptococcus sp., Salmonella sp., Bacillus sp., Klebsiella sp., Escherichia coli and Micrococcus sp.) and five fungal species (Candida sp., Aspergillus sp., Rhizopus sp., Penicillium sp., and Mucor sp.) were isolated. Staphylococcus sp. and Aspergillus sp. had the highest percentage occurrence of 31.55% and 40.38% respectively in personal computers while Bacillus sp. and Aspergillus sp. was predominant in public computers with percentage occurrence of 26.50% and 31.58% respectively. Streptococcus sp. and Penicillium sp. had the least occurrence in personal computers while Streptococcus sp., Candida sp., Mucor sp. and Penicillium sp. were the least in public computers. Statistical analysis showed that only few counts in the Total Heterotrophic Count, Coliform and fungal counts were significantly different at P<0.05 while others were not significantly different.