Bacterial Assessment of Electronic Hardware User Interfaces in Ile-Ife, Nigeria

Abstract

The study was undertaken to quantify and identify bacterial contaminants associated with private and open access user interfaces in various establishments in the town of Ile-Ife, Nigeria. The study was conducted in selected offices, business centres, banks and cybercafés within Ile-Ife. Swab samples were aseptically collected from each user interface (keyboard, mouse, ATM) and users’ hands and cultured on nutrient and MacConkey agar, to determine the total bacterial load and coliform count, respectively, by the pour-plate technique. Bacterial loads present on different types of interface (keyboard, mouse and ATM) were found to be significantly different (p < 0.01). A total of 669 isolates comprising 11 distinct bacterial species were recovered from 313 randomly sampled user interfaces. The frequencies of occurrence of the species were Aerococcus viridans (9.4%), Bacillus spp. (8.4%), Enterobacter aerogenes (4.9%), Gaffkya tetragena (2.1%), Klebsiella pneumoniae (11.1%), Micrococcus luteus (10.9%), Moraxella catarrhalis (1.6%), Proteus spp. (10.6%), Pseudomonas aeruginosa (16.0%), Staphylococcus aureus (16.7%) and Staphylococcus epidermidis (8.2%). All the interfaces examined were contaminated. Contamination on interfaces in educational institutions differed significantly from that found in banks and cybercafés, but was comparable to that in commercial centres. Most isolates were resistant to amoxicillin, augmentin, nitrofurantoin and ceftriaxone, while resistance to ciprofloxacin and ofloxacin was the least frequent. Multiple antibiotic resistance was observed in 89.1% of bacterial isolates, with a total of 68 resistance patterns, resistance to three antibiotics being the most frequent (31.9%). About 74% of multiple antibiotic resistant isolates profiled for plasmid DNA contained either single or multiple plasmids. It was concluded that user interfaces were contaminated with potentially pathogenic bacteria, highly resistant to some commonly used antibiotics. These interfaces are therefore potential vehicles for the transmission of clinically important pathogens.