The Effects of Lysogenic Bacteriophages on Gordonia rubripertincta Superinfection Immunity

The Effects of Lysogenic Bacteriophages on Gordonia rubripertincta Superinfection Immunity

Alvin Sherman Library

Antibiotic resistance is a growing concern in the field of medicine, making an increasing demand for alternative treatments to antibiotics. One option is phage therapy, the use of viruses that specifically kill bacteria. Bacteriophages present two life cycles: lytic, where they rupture the cell, and lysogenic, where they sneak into the host's DNA and remain dormant. Temperate phage can alternate between the two life cycles and when lysogenic can prevent other phages from infecting the bacteria, providing the bacteria with superinfection immunity. This lowers phage therapy’s effectiveness. Our goal is to determine if novel phages that infect Gordonia rubripertincta, a bacterium that can infect immunocompromised patients, are lysogenic. First, possible lysogens will be identified by spotting a dilution series of each phage lysate onto Pyca top agar containing G. rubripertincta and looking for clearings with a mesa after incubation. Next, potential lysogens will be collected from the mesa and purified through several rounds of streaking. To test for the presence of lysogenic phage, the potential lysogens will be grown in liquid culture, allowing for phage release and filtered to isolate any phage present. The filtrates will be diluted and spotted onto Pyca top agar containing G. rubripertincta. A clearing will indicate that lysogenic phage was present. Once the lysogen has been determined, it can be prepared as a top agar lawn and phages can be utilized to test if the candidate is immune to superinfection. Information gained from this research can be applied to the development of effective phage therapy.