Microbiology

PIT tagging juvenile salmon for the 2001-2002 vaccine trials

Microbiology Team is part of the Integrative Fish Biology Program in the Resource Enhancement and Utilization Technologies Division of the Northwest Fisheries Science Center. The team carries out a mix of basic and applied research to support the NOAA Fisheries goals to Build Sustainable Fisheries and Recover Protected Species. These research activities include projects to characterize virulence factors of pathogenic bacteria that cause significant disease in important fishery resources, particularly endangered salmon stocks and other marine fish, or that are part of the normal bacterial flora of marine fish or shellfish and pose a significant threat to human health. We are also working on molecular-based methods for rapid identification of bacteria responsible for causing various fish diseases. These methods have the potential for much greater sensitivity and accuracy, as well as speed in identifying harmful pathogens. We are testing new antimicrobial therapeutics and vaccines for the treatment of a serious disease of salmon, called bacterial kidney disease. We also provide infectious disease diagnostic services for the NWFSC Captive Broodstock Program to rebuild endangered salmon stocks. These services include health certification for these stocks prior to their release in their native habitat.

Please visit the links listed on the left for more specific information about individual team members and projects, or read on for more information on the research strategies we employ.

The overall objective of this research is to mitigate adverse impacts from diseases caused by pathogenic microorganisms. The identification and characterization of virulence determinants at the genetic or molecular level can lead to the development of new molecular-based methods for rapid detection and identification of the pathogens under study, as well as new prevention and control measures directed against specific virulence factors. Virulence factors are those determinants or biological mechanisms utilized by pathogens to cause disease, and include host adherence or colonization factors, destructive toxins, cellular invasion and intracellular survival factors, and other factors that allow a microorganism to evade the host immune system, resist chemotherapeutic drugs such as antibiotics, or to exploit host biological mechanisms for continued survival and multiplication.

In general, research in this laboratory involves the identification of genes encoding specific virulence factors (i.e., whose products are directly involved in virulence), or genes that encode important precursors or enzymes required for complete expression of a virulence mechanism or pathway. We utilize molecular biological, genetic, and biochemical tools to accomplish this. For example, one strategy is to generate a "bank" of randomly placed mutations in the bacterial chromosome and then screen for changes in a phenotype (a measurable characteristic such as tissue cell adherence). The mutated genes can then be isolated (cloned), and the DNA sequenced and compared to large databases of genetic sequences in order to begin the functional characterization of the gene product.