Student Presenter(s): Hamza Nagarwala
Faculty Mentor: Bryan Gibb
School/College: Arts and Sciences, Old Westbury

Methicillin-resistant Staphylococcus aureus (MRSA) is listed as a serious threat by the CDC due to its prevalence and antibiotic resistance. About 2% of all people carry MRSA on their skin or in their nose, which can turn into a severe infection when the skin is broken during injury or surgery. This makes them a potential danger post-surgery, especially in orthopedic surgeries. Surgical site infections of MRSA have a mortality rate of 12.9%. MRSA infections of the bone are difficult to treat with antibiotics, so alternative therapeutic strategies are needed. Bacteriophages are viruses that infect bacteria and may be useful as therapeutics to treat bacterial infections, including those caused by MRSA. To explore the potential of bacteriophage therapy in orthopedic infections, we isolated a bacteriophage that infects a bioluminescent strain of MRSA developed for a mouse-infection model that enables visualization of the bacterial infection in a living mouse. We isolated two phages from commercial cocktails used for treating infections in eastern Europe that infect both the clinical S.aureus strain. These bacteriophages infected the strain inconsistently and only when the host was grown at 30 °C. To improve the therapeutic potential of these bacteriophages, we conducted sequential propagation at 37 °C to select for mutants that infect better at the body temperature of a mouse.