BACTERIAL AND FUNGAL CONTAMINATION OF STAIRCASE BANISTERS AT THE COLLEGE OF SCIENCE, KWAME NKRUMAH UNIVERSITY OF SCIENCE AND TECHNOLOGY, GHANA

Abstract

Staircase banisters are frequently touched surfaces that may receive microorganisms from hands, dust, air and other environmental sources, but their microbial status in Ghanaian university buildings has received limited attention. This cross-sectional environmental microbiology study assessed bacterial and fungal contamination of staircase banisters at the Kwame Nkrumah University of Science and Technology, Kumasi. Six banisters from the Aboagye Menyah Building Complex, Chemistry Block and Biology Block were purposively selected to include high-traffic locations and both wooden and metal surfaces. Upper and lower sections were sampled over three consecutive Monday afternoons after classes, giving 12 surface samples. Approximately 150 cm{superscript 2} of each section was swabbed with sterile buffered peptone water, cultured on standard bacteriological and mycological media, and analysed using phenotypic and morphological methods. Bacterial loads were compared by independent samples t-test. Thirty-one bacterial isolates were recovered. The study found Gram-positive bacteria which accounted for 74% of isolates and Gram-negative bacteria for 26%. Staphylococcus spp., Streptococcus spp., Enterobacteriaceae, Bacillus spp. and Corynebacterium-+ spp. were the main presumptive bacterial groups. Metal banisters had higher mean bacterial loads than wooden banisters (4.38 {+/-} 0.86 versus 1.24 {+/-} 1.44 log10 CFU/mL; p = 0.014), whereas upper and lower sections did not differ significantly (p = 0.539). Fungal growth was detected in all samples, with Aspergillus fumigatus, Colletotrichum spp. and Aspergillus niger being frequent presumptive fungi. The findings support the routine inclusion of staircase banisters in cleaning and disinfection programmes for academic buildings.