Bacteriological Survey of Naira Notes from Diverse Vendors in Olorunda Local Government Area, Osun State, Nigeria

Abstract

This study investigates the bacteriological contamination of Naira notes collected from diverse vendors in Olorunda Local Government Area, Osun State, Nigeria. Currency notes are widely circulated and often exposed to various environmental contaminants, potentially serving as vehicles for pathogenic microorganisms. Using standard microbiological methods, Naira notes of different denominations were randomly collected from major markets and vendors. Each sample was subjected to serial dilution and cultured on selective and differential media at 35 °C for 24 hours. Colony enumeration and biochemical characterization were carried out for bacterial identification. The results showed that all sampled Naira notes harbored significant bacterial loads with total heterotrophic counts ranging from 1.0 × 10¹ CFU/ml on lower denominations to 6.0x10² CFU/ml on higher denominations. Isolates identified include Staphylococcus aureus, Staphylococcus saprophyticus, Vibrio spp., Pseudomonas spp., Corynebacterium spp., Aeromonas spp. and Alcaligenes faecalis indicating both human and environmental sources of contamination. High staphylococcal, coliform and Salmonella-Shigella counts were found, underscoring the risk of disease transmission through currency handling, especially where hygiene is poor. Naira notes are important fomites for bacterial pathogens, emphasizing the need for improved public health education on hand hygiene, regular replacement of old notes and adoption of cashless transactions to minimize the risk of infectious disease spread in the community.