Date of Award

6-2014

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Environmental Science

First Advisor

Dr. Khaled A EI-Tarablly

Second Advisor

Dr. Abdulamjeed S. AI-KhaJeh

Third Advisor

Dr. Ibrahim Hassan Belal

Comments

Two bacteriophages were isolated from untreated raw waste water from AI-Ain sewerage treatment plant. These two phages were active against Salmonella typhimurium and Escherichia coli which known to cause food poisoning diseases in chicken feed. The optimum concentration of the two phages used was found to be 1010 plaques forming unit (PFU ml-1). Bacteriophage 1 (Ø1) was isolated using S. typhimurium as a propagation host and was found to be monovalnet. On the other hand, bacteriophage number (Ø2) isolated using E.coli as a propagation host was found to be polyvalent and lysed Gram positive bacteria including Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis and Enterococcus faecalis and Gram negative bacteria including Proteus vulgaris, Pseudomonas aeruginosa and Shigella dysenteriae. Bacteriophage (Ø1) formed small circular clear plaques (0.5 mm). However, bacteriophage (Ø2) formed small circular clear blue plaques that lack the reddish color observed on the bacterial lawn(0.9 mm). Negatively stained particles of the bacteriophage (Ø1) active against S. typhimurium and bacteriophage (Ø2) active against E. coli fitted the Siphoviridae (B 1) morphotype which consisted of icosahedral heads and base plate. The incorporation of Ca(NO3)2 into peptone-yeast extract agar, nutrient agar and tryptic soy agar was found to increase the number of PFU ml-1 on all the three media types compared to the same medium but without the addition of calcium nitrate. Bacteriophage (Ø1) was found to be more sensitive to the treatments with physical agents that including (freezing, refrigeration, heating, boiling, ultrasonic treatment and Ultra Violet (UV) radiation), and chemical agents including: (chloroform, thymol, hydrogen peroxide, phenol, ethyl alcohol, clorox, iodine, and merthiolate) than bacteriophage (Ø2).Fewer bacteriophage (Ø1) were obtained when propagation hosts were incubated for 0-3 h, in comparison to those incubated for 5-10 h. Meanwhile, fewer bacteriophages (Ø2) were obtained when propagation hosts were incubated for 0-3 h, in comparison to those incubated for 5-10 h. Greater levels of host inoculum resulted in greater phage titers for bacteriophage (Ø1). Also, greater levels of host inoculum resulted in greater phage titers for bacteriophage (Ø2). Greater phage inoculum size resulted in greater phage output for bacteriophage (Ø1). Also, greater phage inoculum size resulted in greater phage output for bacteriophage (Ø2).The application of bacteriophage (Ø1) in corn-soy diet infested with S. typhimurium, or the application of bacteriophage (Ø2) in corn-soy diet infested with E. coli, or the application of bacteriophage (Ø1) and bacteriophage (Ø2) in corn-soy diet infested with S. typhimurium and E.coli significantly (P < 0.05) reduced the population densities of S. typhimurium and the population densities of E.coli compared to the treatments which included the application of living E. coli alone, living S. typhimurium alone or living E. coli + living S. typhimurium. The treatment which received the mixture of the two phages or the application of bacteriophage (Ø1), or the application of bacteriophage (Ø2) was almost as effective as the antibiotic oxytetracycline applications in reducing the incidence of S. typhimurium and E. coli in the chicken feed. In conclusion, the

Share

COinS