Open Access Thesis
Date of Award
Nutrition and Food Science
CHARACTERIZATION OF BACTERIOPHAGES FROM ENVIRONMENTAL WATER SAMPLES AND THE POTENTIAL OF BACTERIOPHAGES TAILSPIKE PROTEINS (TSP) IN BACTERIA DETECTION
GAYATHRI UPEKSHA GUNATHILAKA
Advisor: Dr. Yifan Zhang
Major: Nutrition and Food Science
Degree: Master of Science
The high abundance of phage in the environment and their specificity with the bacteria host make them an excellent tool for bacteria detection. To characterize phage specific to Salmonella and E. coli from water samples in the Southeastern Michigan and to develop a novel bacterial detection method using phage, environmental water samples were collected from rivers and waste water treatment plant (WWTP) in Southeastern Michigan. E. coli and Salmonella phage were isolated from water samples using soft agar overlay technique with multiple indicator strains. Host range of phage was determined using 18 Salmonella strains and 14 E. coli strains. Transmission Electron Microscopy (TEM) was used to visualize the morphology of representative phage. Tailspike Protein (TSP) purified from E. coli O157 phage ФV10 was functionalized on a graphene field-effect-transister (FET). The specificity of TSP and E. coli O157 binding was measured by the shift of Dirac Point. A total of 70 Salmonella phage and 33 E. coli phage were purified. Twelve E. coli phages were able to grow in all 4 E. coli O157 strains tested. Out of 37 host range patterns in Salmonella phage, all the patterns were able to multiply in 3 strains and above. Out of 9 host range patterns observed in E. coli phage, 6 were able to multiply in 3 strains and above. This suggests a broad host range of the phage recovered. According to the TEM pictures, all of the E. coli phages and some of Salmonella phages were tailed phages. Detectable conductance change was observed when E. coli O157 binds to TSP-functionalized graphene FET whereas very small shift in Dirac Point was caused by Salmonella binding, indicating high specificity of E. coli O157 interaction with TSP. In conclusion, phage with broad host ranges is prevalent in water. Phage has the potential to be applied to bacteria detection.
Gunathilaka, Gayathri Upeksha, "Characterization Of Bacteriophages From Environmental Water Samples And The Potential Of Bacteriophages Tailspike Proteins (tsp) In Bacteria Detection" (2014). Wayne State University Theses. 300.