Survey of bacterial contamination and antibiotic resistance pattern of Bangladeshi paper currency notes in Mymensingh city

Paper currency notes, which are transferred from one individual to another, are known to carry microorganisms on their surface. As people have to exchange currencies repeatedly to buy goods and services in their everyday life, risk of spreading infectious diseases may be enhanced. Thus, it is important to identify the bacteria associated with currency and evaluate their multidrug resistance pattern. Consequently, the following study was conducted to determine some common bacterial load and their antibiotic resistance pattern of Bangladeshi paper currency notes circulating in Mymensingh city. Forty paper currency notes, comprising eight denominations from five occupational groups (Fish seller, meat seller, egg seller, vegetable seller and grocer), were collected from Mymensingh city, Bangladesh and subjected to bacteriological analysis. Total viable count, total Staphylococcus spp., total Salmonella spp. and total Escherichia coli counts were calculated, ranging from log 7.48±0.50 to 8.48±0.60 log cfu/paper currency (pc), 5.58±0.42 to 6.10±0.58 log cfu/pc, 5.36 to 5.88±0.38 log cfu/pc and 5.40±0.20 to 5.84±0.20 log cfu/pc, respectively from all denomination paper currency notes. Among the tested notes, 85.83% were found to be contaminated with three different bacterial isolates. Among them, Staphylococcus spp. were found more frequent (95%) followed by E. coli (87.5%) and Salmonella spp. (75%). Furthermore, isolated bacteria were subjected to antimicrobial susceptibility test against 8 commonly used antibiotics. The entire microorganisms tested were found resistant to Amoxicillin, Ampicillin and Ciprofloxacin, but were susceptible to Azithromycin and Norfloxacin. Thus, the present study revealed that most currency notes are contaminated with different common bacteria, including antibiotic resistant ones, and this might pose a severe public health risk.