Types of bacteria isolated from Yemeni Currencies in Sana'a City and potential risk factors

The main objective of this study was to determine the prevalence of bacterial contaminants on Yemeni paper currency notes and coins and some potential risk factors. This study was carried out on 140 paper currency and coins obtained from bus drivers, supermarket cashers and Qat sellers shops in Sana'a city, Yemen.

Swabs were taken from 140 paper currencies and coins and were cultured on Blood and MacConkey agars. Gram stain, biochemical and serological tests were done to identify isolated bacteria.

The percentage of different types of bacteria isolated from the currencies were as follow; Staphylococci spp (22.2%), Alcaligenes spp (11.2%) , Pseudomonas aeruginosa and, Gram positive bacilli  (10.0%), Escherishia coli (9.3%) , Seratia marcescans (6.8 %) , Streptococci spp (5.3%) , Enterobacter aerogene (3.0%) , Klebsilla pneumoniae (3.0%) , Enterobacter cloacae (2.3%) , Yersinia enterocolitica (2.3%) , Citrobacter spp (2.3%) , Gram posative diplococci (1.5%) , Shigella spp (1.5%) , and  same percentage (0.8%) of  Gram negative cocci, Vibrio cholerae, Actinomysis spp, Proteus vulgaris, Proteus mirabilis.

The highest percentage of Gram negative and Gram positive bacteria was found on currencies taken from supermarket cashers (31.4%) and (30.4), respectively. Whereas, lowest percentage were found in currencies taken from bus driver and Qat seller shops.

Yemeni paper currency and coins are contaminated with pathogenic bacteria. Currency contamination is of importance issue to public health as it can provide a vehicle for easy transmission of pathogens between handlers. Therefore, public education on proper handling and great care should be taken during handling of money to avoid cross contamination.