Abstract

Genetic diversity and molecular characterization of Escherichia coli from soil, water and human saliva by RFLP

Author(s): Baby Joseph, D.Jini

Escherichia coli have been intensively studied under various aspects in general bacteriology. Soil and water is a common source of infectious agents and the human saliva contain excess amount of microbes especially E.coli. The genetic variation in different population of E.coli was studied using restriction fragment length polymorphism (RFLP) analysis. Samples such as soil, water and human saliva were collected and the E. coli strains were isolated and screened using the selective media and subjected to Restriction digestion with EcoRI and Agarose gel electrophoresis. Upon molecular characterization, bands digested from E. coli gave five bands of different morphology. Out of the five bands obtained three bands were monomorphic in and all the other bands were polymorphic in all the three samples. Based upon the patterns of E. coli recovery among the different sample types, there is 60% homology that indicates the presence of common genes coding for common protein functions and 40% polymorphism in genes may be due to the variations in the environmental conditions and these polymorphic differences may provide adaptability to a changing climate, or some other trait necessary for the species to survive in the ever-changing world.