College of Veterinary Medicine

Veterinary Microbiology & Pathology

Call Lab Research Topics 


Statement of interest

Current research topics in the Call lab include:

Antibiotic resistance. Since 2000 my lab has studied factors that drive the emergence and maintenance of antibiotic resistance in the absence of antibiotic use with an emphasis on enteric bacteria of cattle. Our current work is focused on multidrug resistance plasmids that that carry blaCMY-2, which is a gene that encodes resistance to third-generation cephalosporins. Our work examines (1) the fitness costs of carrying this plasmid in Escherichia coli and Salmonella enterica, (2) segregational control at cell division, (3) mobilization of plasmid-encoded transposons to new plasmids and mobilization of the plasmids to new host cells, and (4) transcriptional control of plasmid encoded genes. We are also engaged in studies that examine the source, fate, and transport of antibiotics in the environment with a special focus on the biological consequences of these drugs and the subsequent impact on public and animal health and welfare.

Type III secretion systems (T3SS). A T3SS is a needle-like apparatus that pathogenic bacteria (Gram negative) use to inject bacterial proteins (“effectors”) into host cells where the proteins can interrupt cell division, change cell morphology and behavior, and induce cell death through a variety of mechanisms. We are particularly interested in identifying effector proteins and determining their biological function with a focus on the food-borne pathogen, Vibrio parahaemolyticus. We are also engaged in studies of the transcriptional regulation of T3SS genes and in assessing the biological relevance of T3SS effector proteins using animal models.

Bacterial diseases of salmonid aquaculture. Bacterial coldwater disease, caused by Flavobacterium psychrophilum, is the leading cause bacterial disease losses to salmonid aquaculture in the Pacific Northwest. My lab has helped delineate the population genetic structure of this pathogen and we are actively engaged in efforts to develop vaccines and diagnostics to prevent and control this important disease. My lab is also engaged in research to identify the etiologic agent of strawberry disease in rainbow trout for which we have identified a rickettsial-like organism as the probable agent.

 

Other projects. My lab is involved in continuing work on a variety of projects involving other important pathogens (Campylobacter jejuni; S. enterica serovars Typhimurium, Newport, Enteritidis, and Dublin; norovirus; and Listeria monocytogenes) and my group is involved in collaborative work in environmental microbiology, water quality, pathogen detection, protein expression, and molecular epidemiology.

 



Last Edited: Jul 06, 2009 2:38 PM
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