Jai Narain Singh Yadav obtained MVSc from Indian Veterinary Research Institute and did his PhD (Bacteriology) from Central Drug Research Institute (CDRI), Lucknow under the supervision of Dr BN Singh. He was Senior Scientist and CSIR Emeritus Scientist at CDRI. Academic and Research Achievements: Yadav has made researches regarding transferable multi-resistance against 16 antibiotics at a time among Escherichia coli strains responsible for causing gastroenteritis (diarrhea). This resistance property of bacteria against many antibiotics was found transferable from one strain to another and also from one genus of bacteria to another. Further studies showed that not only drug resistance character but also characters which are responsible for making a bacterium pathogenic and virulent, are also present in bacterial plasma and can be transferred to other bacteria either by conjugation or by transduction with the help of viruses or bacteriophages. Therefore, without transferring the chromosomes of bacteria, such plasmid characters can be transferred. On further studies such characters are given the name of episome or plasmids. He also developed superior anti-diarrheal drugs and gave a formula for oral rehydration solutions. He has shown drug resistance in intestinal bacteria of human and animal origin. By the use of typing techniques, he showed plasmid control multiple drug resistance. He has shown that these plasmids can be readily transferred to entro-pathogenic (or non-pathogenic) E. coli and Salmonella typhimurium by conjugation and phase-mediated transduction. Plasmids responsible for colicin production could increase the virulence of the non-invasive strain which may even cause generalized infection. The alcoholic extract of Andrographis paniculata (Kal Megh) exhibit significant antidiarrhoeal activity against E. coli enterotoxins in the animal models which lead to the isolation of four diterpenes: (i) andographolide, (ii) neo-andographolide, (iii) deoxy-andographolide and (iv) ando-graphoside. Among these, andographolide and neo-andographolide showed similar activity to that of loperamide (a well known antidiarrhoel against E. coli ST, LT and LT/ST enterotoxins). Androgapholide was found to be superior against ST enterotoxins. Now these drugs are available in the market. Other Contributions: Dr Yadav served as Chairman of the UP Veterinary Council. He was Editor, Indian Journal of Animal Research, and Chief Editor of the Indian Veterinary Medical Journal for 25 Years. Awards and Honours: Yadav was founder fellow of National Academy Sciences (1995) and Fellow of Indian Association of Veterinary Microbiologists, Immunologists and Specialists in Infectious Disease (2008).