Traces of DNA footprints of at least 78-disease causing micro-organisms were found on Rs 10, Rs 20 and Rs 100 notes, according to a government study in India.
Currency notes as samples were collected for the study from street vendors, grocery shops and local market places of South Delhi by scientists from Institute of Genomics and Integrative Biology under the Council of Scientific and Industrial Research.
The study was to see how currency notes often spread disease. "To be sure, the study only looked at finding traces of DNA. So we know what kind of organisms could have been on these notes. We do not know whether these organisms have the ability to infect people with the disease because we did not study that aspect. But what we can certainly say is that there is a possibility of diseases spreading through this manner because the microbes do actually travel through currency notes", said S Ramachandran, who led a group of five students for the study. Mostly fungi was found in their samples but also presence of bacteria which can cause tuberculosis, dysentery and ulcers were found.
Studies like these have been conducted earlier which looked at identifying organisms on furniture, clothes, soaps and even computers using a technology called Ribosomal RNA typing.
"We have used a different technology, high-throughput DNA sequencing, for our study. This is a relatively new technology and much more powerful. Using this technology, we can extract lots of information even from a very small amount of DNA material. The other benefit of this method is that even those microbes which cannot be cultured can be detected," added Ramachandran.
Using the DNA sequencing technology, the organisms were identified following which the results were put through a bio-informatics algorithm, where they found some antibiotic resistance genes. They said that when a person is infected by that gene, then they would develop resistance to certain antibiotics.
They want to take the study further and assess the diseases that spread from currency notes, as they found the results to be an eye-opener.