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Show 207 THE UNIVERSITY OF UTAH BACKGROUND Since the first use of antibiotics in the 1940s, we have seen bacteria develop mutations that have resulted in procuring resistance towards them. One bacteria that has acquired resistance to many antibiotics is Staphylococcus aureus, which is responsible for causing many infections. Because of its resistance to antibiotics, new means of preventing and treating these infections must be researched and developed. Bacteriophage therapy has become a popular area of research as an alternative to antibiotic use. It is paramount to characterize any bacteriophage before use as a therapeutic agent. One impor-tant characteristic is the thermal stability, which determines the shelf life of the product. METHODS We chose to study Staphylococcus phage K as it is known to attack a number of S. aureus strains. Microfuge tubes were filled with known concentrations of the phage and placed in a water bath set at 55, 60, or 65°C. At each temperature, samples were taken at a specific time interval over a total time period. At each interval, the phage was spotted on a bacterial lawn (S. aureus Xen 29) and allowed to incubate at 37°C for 24 hours. After 24 hours, the PFU (plaque-forming units) were counted and recorded. A control was run by spotting a sample of the phage stock stored at 4°C both at the beginning and the end of each temperature experiment. RESULTS At 55°C, the phage showed some thermal stability. The control tube had a value of 1.0x109 PFU/ mL after exposure for 60 minutes, compared to the test sample, which only dropped to 3.58x108 PFU/mL. At 60 and 65°C, the survival time of the phage dropped dramatically. At 60°C, the con-centration dropped from 1.08x109 PFU/mL to 2.0x103 PFU/mL in 15 minutes. After 15 minutes no viable phage were detected. At 65°C, the concentration dropped form 1.55x109 PFU/mL to 6.5x106 PFU/mL in just 3 minutes. After 3 minutes no viable phage were detected. THERMAL STABILITY OF STAPH PHAGE K Kasey Brewer (Catherine Loc-Carrillo) Department of Orthopedics University of Utah (George E Wahlen) Veterans Administration, Health Care System health sciences leap program Kasey Brewer Catherine Loc-Carrillo |
