Contamination of Nigerian Currency Notes by Escherichia coli in Nasarawa State University, Keffi, Nigeria

Many environmental materials serve as vehicles for transmission of bacterial agents to humans. Paper currencies are widely exchanged for goods and services worldwide; and can act as vehicles for transmission of potential pathogens. This study investigates carriage of Escherichia coli on Nigerian currency notes circulating in Nasarawa State University, Keffi. A total of two hundred (200) naira notes were collected between June and September 2010 in separate sterile containers from food sellers, bus assistants, students and banks. Sterile swabs dipped in sterile normal saline were used to swab the surfaces of the notes and then streaked on MacConkey agar and eosin methylene blue agar to recover the target organism. Isolated bacteria were tested for their susceptibility to commonly used antimicrobial agents as described by the United States' Clinical and Laboratory Standards Institute. 100 (50%) of total samples were contaminated with E. coli. Isolates were most susceptible to ciprofloxacin (66%), pefloxacin (64%), gentamicin (64%) and streptomycin (50%); and least susceptible to co-trimoxazole (25%), ofloxacin (28%) and amoxicillin-clavulanate (26%). Resistance to more than two antibiotics was observed in the isolates. It can be concluded that Nigerian currency (Naira) notes circulating in Nasarawa State University, Keffi carry high burden of E. coli and can serve as vehicle for transmission of this organism.