16 January 2013 | EN
Scientists have developed a faster and cheaper test to detect diarrhoea caused by Escherichia coli
[DHAKA] Scientists from Bangladesh and Japan have developed a cheap and rapid diagnostic technique to identify strains of a common bug that causes diarrhoea.
Scientists had earlier identified over ten genes from five strains of the bacterium Escherichia coli that can cause diarrhoea in humans.
Earlier tests involved identifying each individual gene, a costly process that took four to five hours for each gene.
Two-step or single-step genetic tests were also developed earlier, but these could not detect all the concerned genes. These tests were based on the polymerase chain reaction (PCR) technique that amplifies genes to make their detection easier.
The new PCR test, to be published online in the Journal of Microbiological Methods, identifies ten specific E. coli genes in a single reaction, saving time and money. It was developed by a team of scientists from the University of Hirosaki, Japan, and Dhaka University (DU).
In their report the scientists said the new test would be a valuable contribution to routine diagnostic tests while also providing valuable information for physicians and researchers.
"A physician treating a patient with diarrhoea would be able to find out his ailment much faster and also, it would cost far less than the conventional method of culturing stools for 24 hours," Chowdhury Rafiqul Ahsan, one of the three authors of the report, told SciDev.Net.
Diagnostic laboratories in Dhaka now charge between US$ 23 and US$ 71, depending on how quickly gene matches are obtained. Against this, the new test identifies all ten possible causative genes in a single test that could, on commercialisation, cost less than US$ 7.
Ahsan, a senior academician at the department of microbiology at DU, told SciDev.Net that the "biggest advantage of the highly reliable technique is (that) it enables us to detect the exact cause of the infection in less than 3–4 hours."
Azharul Islam Khan, head of the diarrhoeal diseases unit at the International Centre for Diarrhoeal Disease Research, Bangladesh, said the development was significant for public health. "Last year we found about 12 per cent of all diarrhoea patients suffering from E. coli infection, considered almost as deadly as cholera."
E. coli infection is characterised by rapid discharge of liquid stools which can be fatal if immediate rehydration therapy is not given, Khan added.
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