A Bacteriologic Investigation On Sudanese Coins In Khartoum North Rovince

The objective of this study was to examine the extent of bacterial contamination of the most used coin denominations of the Sudanese currency. A total of 72 coins of three different denominations (10, 20, and 50 SD) in circulation inside Khartoum North province were randomly studied for bacterial contamination. Sources of samples collection were groceries, cafeterias, bus drivers and elementary schools pupils during the period from February 2006 to August 2006. Samples were cultivated on appropriate media and identification of isolated bacteria was accomplished by conventional methods. Results showed that all tested coins, except one, had bacterial growth, 84 (92%) were Gram positive bacteria while only 7 isolates (8%) were Gram negative bacteria. The predominant genus isolated was Bacilluswhich constituted 90.1% of the total bacteria and included B. cereus,B. mycoides, B. thuringiensis, B. subtilis, B. pumilus,B. licheniformis, and others. The other bacteria identified were Staphylococcus epidermidis andEscherichia coli (2.2%),Citrobacter freundiiand Klebsiella pneumoniae(1.1%). The frequency of bacterial isolation from different sources was 20.9% for groceries, 19.8% for cafeterias, 26.4% for bus drivers and 32.9 % for elementary schools. The rate of bacterial isolation was the same for all coin denominations. For Bacillusspp subjected to antibiotic sensitivity test all isolates were sensitive to tetracycline, chloramphenicol, erythromycin and gentamycin. All Bacillus cereusgroup showed resistant to penicillin, ampicillin and cloxacilin. For streptomycin, all of them were sensitive except two isolates of B. licheniformisone was resistant and the other was intermediate