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 (“effectorsâ€) 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
