Characterization of Pathogenic Bacteria Isolated from Sudanese Banknotes and Determination of Their Resistance Profile

BACKGROUND: Banknotes are one of the most exchangeable items in communities and always subject to contamination by pathogenic bacteria and hence could serve as vehicle for transmission of infectious diseases. This study was conducted to assess the prevalence of contamination by pathogenic bacteria in Sudanese banknotes, determine the susceptibility of the isolated organisms towards commonly used antibiotics, and detect some antibiotic resistance genes. METHODS: This study was carried out using 135 samples of Sudanese banknotes of five different denominations (2, 5, 10, 20, and 50 Sudanese pounds), which were collected randomly from hospitals, food sellers, and transporters in all three districts of Khartoum, Bahri, and Omdurman. Bacterial prevalence was determined using culture-based techniques, and their sensitivity patterns were determined using the Kirby–Bauer disk diffusion method. Genotypic identification was carried out using PCR and 16S rDNA sequencing. Antibiotic resistance genes of some isolates were detected using PCR technique. RESULTS: All Sudanese banknotes were found to be contaminated with pathogenic bacteria. Klebsiella pneumoniae was found to be the most frequent isolate (23%), whereas Bacillus mycoides (15%) was the most abundant Gram-positive isolate. There was a significant relationship between the number of isolates and the banknote denomination with p value <0.05 (the lower denomination showed higher contamination level). Our study has isolated bacteria that are resistant to penicillins and cephalosporins. Multidrug-resistant strains harboring resistant genes (mecA, blaCTX-M, and blaTEM) were also detected. CONCLUSION: All studied Sudanese banknotes were contaminated with pathogenic bacteria, including multidrug-resistant strains, and may play a significant role in the transmission of bacterial infections.