A seminar talk entitled: “Bacterial Cross-talk and Ecology of the Cholera Pathogen” will be delivered by Professor Shah M Faruque, Ph.D., Coordinator, Life Sciences, Department of Mathematics and Natural Sciences (MNS), BRACU.
Venue: UB#21803 (GDLN Centre)
Date: Thursday, January 25, 2018
Understanding the genetic and ecological conditions which support the emergence of new pathogenic bacteria and the spread of bacterial epidemics is vital to developing appropriate preventive measures. Vibrio cholerae the causative agent of the epidemic diarrhoeal disease cholera represents a paradigm for this process in that this pathogen evolves from non-pathogenic bacteria which are normal inhabitants of the aquatic environment. We have discovered the detailed genetic pathway involved in conversion of naturally occurring non-toxigenic V. cholerae strains to toxigenic strains with epidemic potential.
Although cholera is known to be transmitted by water contaminated with pathogenic V. cholerae, routine isolation of the pathogen from aquatic environments is challenging. We have demonstrated that pathogenic V. cholerae exist in water as “conditionally viable environmental cells (CVEC)” which are aggregates of dormant cells that resist cultivation by conventional techniques. We found that the reversible transition of V. cholerae to the dormant form involves quorum sensing, which is a regulatory mechanism in bacteria based on density of bacterial population, and sensing of signal molecules called autoinducers. Our results support a model of cholera transmission in which dormant V. cholerae cells in water are dramatically reactivated on exposure to autoinducer signals. As well as shedding important light on the ecology of the pathogen, our findings raise the prospect of improved methods of surveillance, and prevention of cholera, and possible other waterborne bacterial pathogens that have dormant states. Furthermore, autoinducer molecules or compounds that inhibit these molecules may have potential therapeutic implications, since bacterial pathogenesis may also involve quorum sensing.
Short Biography of the Speaker:
Professor Shah M. Faruque was the director of the Genomics Centre at the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), and formerly director of the Centre for Food and Water Borne Diseases in icddr,b. He obtained his B.Sc (Hons) and M.Sc degrees in Biochemistry from Dhaka University, and a Ph.D. in Molecular Biology from the University of Reading in the United Kingdom. He was a Commonwealth Scholar in the UK.
Prof. Faruque began his research career at the University of Reading in England, and conducted basic research in hormonal regulation of gene expression. After holding faculty positions in Dhaka University, he moved to icddr,b to establish the Molecular Genetics Laboratory and initiate research in genetics, evolution, and molecular ecology of diarrhoeal pathogens. Recently, he has established the Genomics Centre in icddr,b with financial support by the Swedish International Development Cooperation Agency (SIDA).
Prof. Faruque has authored more than 140 original research papers, reviews, and book chapters, and has edited a number of text books. His research findings have been published in top ranking scientific journals, including PNAS and Nature.
In recognition of his outstanding contributions to research, he was awarded the TWAS Prize-2005 in Medical Sciences. Among other recognitions, he is also the first Bangladeshi scientist to receive a Senior Investigator Award of the Wellcome Trust. Prof. Faruque is an elected Fellow of TWAS, the World Academy of Sciences, as well as a Fellow of the Bangladesh Academy of Sciences.