Water & Wastewater Asia Jul/Aug 2018

WATER & WASTEWATER ASIA July / August 2018 64 Professor Colwell invented a new approach using whole genome sequenc i ng and spec i a l i sed databases to identify different strains of bacteria and determine their virulence and resistance to antibiotics. She started focusing on translating the use of this rapid diagnostic technology to a wide range of applications in recent years. QN: What is the rapid diagnostic technology and how does it work? PC: T h e r a p i d d i a g n o s t i c technology we now use is simply extracting DNA from a water sample, sewage sample, food sample, or clinical sample, and determining the DNA sequences of microorganisms using any of the available sequencing machines. The sequences are then analysed using algorithms we have developed in our bioinformatics research that can match the fragments against our carefully curated libraries. We have thus far removed any contaminating DNA in the libraries for approximately 150,000 microorganisms, namely bacteria, fungi, viruses, and parasites, i nc l ud i ng a l l known human pathogens the DNA of which has been sequenced, allowing us to identify within minutes all microorganisms, present in the sample being analysed, as well as the species and strain they belong to very accurately within minutes. QN: Yo u a n d y o u r t e a m introduced the use of saris to filtered water in India in 1990 and rapidly reduced the spread of cholera in Bangladesh by 48 per cent in 65 villages. This was later introduced to other cholera- endemic areas in India and South America. Why use cotton saris? PC: Because we had discovered that Vibrio cholerae was associated with plankton, we thought we could reduce cholera if we filtered the plankton from the water that was used for drinking by Bangladeshi villagers, so we tested a variety of materials. We tested men’s T-shirt material, Chinese poplin material, and other possible filtrationmaterials available in Bangladesh for the least possible cost. As it turned out, sari cloth, not new and expensive, but the least expensive cloth that had been used and discarded for cleaning, dusting, and so forth was the most effective. Also, if a yard Professor Rita Colwell, Lee Kuan Yew Water Prize 2018 Laureate