Bacteriological Quality Assessment of Nigerian Naira Notes in Circulation at Aminu Kano Teaching Hospital, Kano State, Nigeria

Contamination of currency notes by pathogenic microorganism is a public health concern. An improved understanding of the bacteriological quality of currencies would help us better understand the role of money as a medium of transmitting infections. This study investigates the bacteriological quality of Nigerian currencies circulating in Aminu Kano Teaching Hospital (AKTH) in Kano metropolis. A total of 128 Naira note samples containing 16 pieces of each denomination of 5, 10, 20, 50, 100, 200, 500 and 1000 were aseptically collected from different cash units of the hospital and subjected to standard microbiological methods for the enumeration and isolation of bacteria. The susceptibility of the bacterial isolates to antibiotics was investigated using disk diffusion method. The mean aerobic mesophilic bacterial count of the currency notes range between 3.10 x104 cfu/mlto 5.25 x104 cfu/ml. Different bacterial species were isolated which include E. coli, Klebsiella spp, Staphylococcus aureus and Coagulase negative Staphylococci, with S. aureus having the highest frequency of occurrence of 37 (46.2 %). Findings of antibacterial susceptibility test indicated that100% of the isolated Gram negative bacteria were susceptible to Meropenem, followed by susceptibility to Gentamycin and Ciprofloxacin. However, the isolates were found to be highly resistant to Augmentin (55%) and Cefuroxime (32%). On other hand, the Gram positive bacterial isolates were highly susceptible to Erythromycin (84%), Gentamycin(83%), Clindamycin (79%),and Oxicillin (78%) while few of the isolate showed resistance to Penicillin(24%), Oxacillin (22%), and Clindamycin, (16%). The study reveals that currency notes in circulation at AKTH may serve as vehicles for the spread of disease causing organisms. Cashless transactions and use of hand sanitizers is therefore recommended to reduce the risk of infection.