Showcase of Undergraduate Research and Creative Endeavors (SOURCE)

Isolation and Characterization of Novel Bacteriophages at Winthrop University

In the fall of 2021, Winthrop University students discovered and characterized eight phages as part of the SEA-PHAGES program, led by the Howard Hughes Medical Institute and Dr. Graham Hatfull at the University of Pittsburgh. The goal of the SEA-PHAGES program is to isolate and characterize soil bacteriophages. Each student in the course isolated, purified, and characterized a bacteriophage using host bacteria Mycobacterium smegmatis. Soil samples were collected on the Winthrop University campus, and then amplified using enriched or direct isolation. Purification was performed to ensure a well-isolated sample. Amplification strategies were employed to increase the viral titers. DNA was extracted and characterized using restriction enzymes and gel electrophoresis to evaluate unique patterns. Transmission electron microscopy was used to determine phage morphology and size. Bacteriophages Virgeve, Figment, Yorick, Galaga, Purah, Stay, Mazikeen, and Mikro were described. All were Siphoviridae morphology with the exception of Stay and Mikro, Winthrop’s first two Myoviridae phages. Based on restriction digest results, three phage DNA samples were sent to the University of Pittsburgh for sequencing. Virgeve was determined to be a B1 cluster, while Yorick was an F1; both of these phages contain 101 potential genes. Mikro was found to be a C1 cluster with 225 potential genes. Annotation of these genomes is currently in progress and the results will be published in NCBI’s GenBank.