Project

Isolation and Characterization of Bacteriophage Against Enteric Pathogens from Sewage

Improper sanitation and lack of drinking water ultimately results in the enteric infection and there by leads to huge malnutrition and other health problems in developing nations. Solving the sanitation challenge in the developing world will require radically new innovations that are deployable on a large scale. We aim to reduce the bacterial load of waste water by developing bacteriophages from sewage against the enteric pathogens. Bacteriophages  are very specific viruses targeting bacteria and hence can safely be used to kill the bacterial pathogens without affecting the human host or any non target organisms in waste water. Thus they can be used to treat human waste and waste water safely. We developed broad spectrum phages by simply filtering the sewage water from different regions of Amritapuri campus through 0.22µm filter, enrich the filtrated virus stock against all the waste water microbes by culturing them in different enrichment media recommended for different classes of  bacteria  such as Vibrio, Shigella, coliforms and nutrient broth media. We isolated specific plaques from different bacterial colonies isolated from the waste water cultured on different enrichment media. Thus we got phages against clinical strains of multidrug resistant E. coli, Vibrio, Salmonella and environmental strains of Salmonella and determined their titre. Best titre was obtained for clinical Salmonella at 5.7×10^8.  We could not get any phage against Shigella. The isolated strains from sewage was biochemically tested for their identification.

Recent literature shows that vertebrate gut might be actively hosting the phages to kill the bacterial pathogens. We intend to explore the possible molecular entities of phages interacting with host extra cellular matrix proteins such as Fibronectin, Gelatin. We chose phages against E. coli to explore the interaction. The phage plaques from E. coli colonies were grown in Luria Bertani(LB) media and filtered through fresh lysate was passed through the gelatin, fibronectin  affinity columns to check for the interaction of the specific phages with the matrix proteins. The E. coli phages did not bind to gelatine but they bound to fibronectin. The results need to be further confirmed. Urea reduced the titre of the E. coli phages.