Ka Yin Leung, Ph.D.

Professor of Biology
Dean, Faculty of Natural and Applied Sciences

Biology Department
Trinity Western University
7600 Glover Road
Langley, BC V2Y 1Y1

Ph: (604) 513-2121 (3253)
Fax: (604) 513-2018

Adjunct Professor of Molecular Biology and Biochemistry, SFUblueline


B.S.A. (Hons.), University of Saskatchewan, 1980
M. Sc., University of Saskatchewan, 1982
Ph. D., University of Guelph, 1987

Work Experience


Dean of Natural and Applied Sciences and Professor of Biology, Trinity Western University (TWU)


Associate Professor (01-present, with tenure to 65), Senior Lecturer (98-00), Teaching Fellow (95-98), NSTB Fellow (94), Department of Biological Sciences (DBS), National University of Singapore (NUS), Singapore


Deputy Head, DBS, NUS


Assistant Dean (Research), Faculty of Science, NUS


Associate Director, Tropical Marine Science Institute, NUS


Sabbatical in the laboratory of Prof. Brett B. Finlay, Michael Smith Laboratory, University of British Columbia, B. C., Canada


Visiting Professor, Xiamen University, Xiamen, China


Visiting Professor, Sun Yat-Sen University, Guangzhou, China


Chief Scientist at International Chitin Production Inc., Vancouver, B. C.


Research Associate in the laboratory of Dr. Brett B. Finlay, Biotechnology Laboratory, University of British Columbia, B.C., Canada


Postdoctoral Fellow in the laboratory of Dr. Susan C. Straley, Albert B. Chandler Medical Center, University of Kentucky, KY., USA

Research Interests

Bacterial Pathogenesis, Characterization of Virulence Factors, Type III and Type VI Secretion Systems (T3SSs and T6SSs), Effector Study and Host Response, Development of Diagnostics, Vaccines and Novel Drugs.

I have been examining virulence factors in several pathogens such as proteases in Aeromonas hydrophila, YopM in Yersinia pestis, and intracellular replication in Salmonella species. During the past 15 years in Singapore, my laboratory has been focusing on several fundamental questions in bacterial pathogenesis. For example, what makes a bacterium pathogenic? And what are the roles of secretion systems in bacterial pathogenesis? I look for answers in several aquatic and/or human pathogens, namely A. hydrophila, Edwardsiella tarda, enterohaemorrhagic and enteropathogenic Escherichia coli (EHEC and EPEC). My goal is to examine steps or processes these bacteria undergo inside the host during infection and to identify the corresponding bacterial genes involved. From the hundreds of putative virulence factors, we have narrowed down the search to a few key systems and main switches that control the common virulence features of these pathogens. Among them, bacterial secretion systems are found to be the critical components for bacterial pathogenesis. With our discoveries of type III and type VI secretion systems (T3SS and T6SS) in A. hydrophila and E. tarda, our studies of bacterial pathogenesis have now reached a most exciting stage, with great promise towards finding newer approaches for the control of microbial infections.

Our current effort is to study the function, regulation and mechanism of T3SSs and T6SSs and to characterize the effector proteins and cross-talk between these systems. Our long term goal is to understand regulation and interaction of multiple secretion systems in a single pathogen. We will study distribution and expression of different secretion systems in different pathogens and see whether there is a common trait. Questions we will address include: What are the minimal types of secretion systems that must be present in a bacterium to make it pathogenic? When bacteria move from the environment and invade a host and later establish inside the host, how are these secretion systems coordinated in order to facilitate the exploitation? Knowledge generated will be important to understand pathogen-host interactions as well as for the development of biotechnological and therapeutics applications. These include rapid and sensitive diagnosis, vaccine therapy, food safety and quality control, and screening of new drugs against human and animal diseases. This research therefore, is of global importance, and will promote the knowledge-based economy in Canada.


Research Grants

Graduate Students Supervised