Trevor Kane received his Bachelors of Science in Molecular and Cellular Biology with a minor in Economics from the University of Puget Sound in 2010. During his undergraduate time he worked two summers at the Mayo Clinic in the lab of Dr. Sundeep Khosla researching the effects of bisphosphonate treatment on osteogenesis genes in endothelial progenitor cells. Following a year serving in AmeriCorps in a high school assisting with Biology classes, English classes, and pre/post school tutoring he joined the Ph.D program at the University of Notre Dame in the lab of Dr. Shaun Lee. Trevor researches a gene cluster in a select strain of methicillin resistant Staphylococcus aureus that is highly similar to a potent virulence factor found in Streptococcus pyogenes. Trevor aims to graduate with his degree in May 2017, and upon completion of the Ph.D he aims to transition directly into industry. He has strong interest in the fields of agriculture, intellectual property, and patent examining.
Examination of a potential new virulence factor in a select strain of methicillin resistant Staphylococcus aureus
University of Notre Dame, Eck Institute of Global Health
Methicillin antibiotic resistant Staphylococcus aureus (MRSA) is a human pathogen responsible for roughly 15,000 deaths a year in the United States. Recently, the streptolysin-associated gene (sag) cluster has been discovered in an especially virulent subset of human S. aureus strain, JKD6159. The sag cluster was previously identified in Streptococcus pyogenes and is responsible for the biosynthesis of Streptolysin-S (SLS), a potent cytotoxin and virulence factor of Group A Streptococcus. SLS as produced by S. pyogenes is hypothesized to be heavily post- translationally modified as well. In the case of S. aureus we hypothesize that the SLS-like toxin may serve as an antibiotic, hemolysin and/or cytotoxin. We have created an isogenic null mutant in the sagB gene in JKD6159, and no growth defects were observed in the mutant. Conditioned media (25%) from JKD6159 wt and sagB null mutants have been tested against early growth E. coli and S. epidermidis to observe antibacterial effects by measuring OD600. No inhibition of E. coli or S. epidermidis was observed. We have observed a significant decrease in cytotoxicity upon transwell culture with HACAT keratinocytes cells, implying that the SLS-like cluster in JKD6159 may be a produce a cytotoxin. We are using two methods to determine the hypothesized post-translational modifications the toxin is theorized to undergo. We have constructed his-tagged inducible toxins that have been expressed in wt JKD6159. Mass spectrometry analysis of proteins obtained from the cobalt column is underway. We are also utilizing E. coli based protein expression and purification system using MBP to generate the active toxin in vitro. We have also undertaken 2D proteomics to determine if the SLS-like cluster functions in a quorum sensing role. Results from those experiments show differential expression of several RNA polymerase subunits, ABC transporters, and isomerases.