Cullen is presently a post-doctoral fellow with Dr. Eric Brown at McMaster University. Originally hailing from St. Lucia, a tiny island nation in the south eastern Caribbean, Cullen completed his Hons B.Sc. at the University of Toronto in 2003, specializing in biochemistry, molecular biology and genetics. He returned to St. Lucia for a stint in fisheries biology studying large marine predators, and then went on to receive an M.Sc., with distinction, in Applied Biomolecular Technology from the University of Nottingham in 2007. Cullen completed his PhD in Chemistry at the University of Waterloo in 2013 under the supervision of Prof. John Honek, studying resistance mechanisms to the natural product antibiotic thiostrepton and developing of semi-synthetic thiostrepton derivatives as biological probes and potential antibacterial agents.
 
Cullen’s current research continues long-standing interests of the Brown lab in understanding bacterial cell wall homeostasis. He is focused specifically on the enzymology, and possible physiological relevance, of the degradation of cell wall teichoic acid, an abundant glycopolymer found in the cell wall of Gram-positive bacteria. Wall teichoic acid is important for several aspects of bacterial physiology, notably including virulence and antibiotic resistance, and the wall teichoic acid biosynthetic pathway has been validated as an antibacterial target. Research into the genetics and enzymology underlying wall teichoic acid degradation may therefore have implications for the development of novel strategies to combat drug-resistant Gram-positive pathogens such as MRSA.