Iranian Journal of

Background and Objectives:

handling of food and money contributes to the incidence of food-related public health incidents.

The objective of this study was to determine the total bacterial count and the presence of food borne

bacterial pathogens on Iranian currency notes, collected from food-related shops.

Materials and Methods: A total of 120 Iranian currency notes, comprising notes in four  denomination (2000, 5000, 10000 and 20000 R) were collected from various food-related shops including, butchery, bakery, confectionary, fast food, ice cream and poultry meat shop. The currency notes were categorized into three groups according to their physical conditions. All currency notes were examined for total bacterial count, Escherichia coli, Staphylococcus aureus, Bacillus cereus, Salmonella and Listeria according to the standard techniques.
Results: The average number of total bacterial count in four denomination of currency notes (2000,  5000, 10000 and 20000 R) were 118.49, 106.32, 69.44 and 220.81 CFU/cm2, respectively. The association between total bacterial count and denomination of the currency was not statistically significant. Of the 120 currency notes on which bacteriological analysis was conducted 13.3 %, 32.5% and 10.8 % were contaminated with E. coli, S. aureus and B. cereus, respectively. Salmonella and Listeria were not isolated from samples. Currency notes collected from butchery, bakery, confectionary, fast food, ice cream and poultry meat shop were contaminated with E. coli at the rate of 60, 0, 5, 5, 0 and 10 % with S. aureus at the rate of 55, 30, 10, 25, 40 and 35 % with B. cereus at the rate of 0, 10, 20, 5, 20 and 10 %, respectively. There was not a statistically significant association between physical condition and bacterial contamination of the currency notes. The effect of presence or absence of cashier in food-related shops on bacterial contamination of the currency notes was also evaluated.
Conclusion: Money has got the potential to change through many different hands and could be  exposed to many different environments at a relatively high frequency. Since there is very little information regarding the hygienic history of any forms of currency, great care should be taken when the same person facilitates the handling of money and the preparation and handling of food to avoid cross contamination.

Background & Objectives: Listeria bacterium resists to the sludge digestion conditions and Listeria monocytogenes is the most important of them. Sludge produced in the north Isfahan wastewater treatment plant is stabilized by anaerobic digesters and is used for fertilizing agricultural lands after drying in the sludge drying beds. Based on the importance of the subject, the objective of this study was evaluation of sludge processing units efficiency, particularly anaerobic sludge digestion for reduction or removal of Listeria. Materials and Methods: In this descriptive study, samples were collected weekly from sludge processing units 13 times in north Isfahan wastewater treatment plant according to standard methods over three months. Listeria bacteria were enumerated and isolated by triple-tube fermentation method and U.S Department of Agriculture method respectively. Isolated Listeria were confirmed by phenotypic method and then bacterial species were diagnosed differentially by biochemical carbohydrate fermentation and CAMP test. Results: Contamination of raw, stabilized and dried sludge at least to one of L. Monocytogenes, L. Innocua and L. Seeligeri species was 100, 92.3 and 53.8 percent respectively. Anaerobic sludge digesters efficiency to remove L. Monocytogenes, L. Innocua and L. Seeligeri species was determined 64.7, 39.72, and 100 percent while the efficiency of drying sludge beds for L. monocytogenes and L.innocua species removal was 73.4 and 96.68 percent respectively. Conclusion: Listeria monocytogenes is more resistant than other identified species against the sludge processing conditions. Thus, the use of sludge as fertilizer can cause the spread of this bacterium in the environment and agricultural products pollution.