UI Center for Research on Invasive Species and Small Populations UI Center for Research on Invasive Species and Small Populations University of Idaho College of Natural Resources University of Idaho College of Agricultural and Life Sciences Image Map
Aug 072012
 

Title: Development and optimization of an Enzyme-Linked Immunosorbent Assay (ELISA) to detect Flavobacterium psychrophilum, etiologic agent of bacterial coldwater disease and rainbow trout fry syndrome in salmonids
Student: Nicole M. Lindstrom
Department: Fish & Wildlife Resources

Project Summary

There is strong evidence that Flavobacterium psychrophilum, the etiologic agent of coldwater disease (CWD), is transmitted vertically and it has been hypothesized that disease management at hatchery facilities may be improved through broodstock screening and implementation of culling programs. This study describes the development of two assays to screen broodstock tissues (kidney and ovarian fluid) for the presence of F. psychrophilum. Four monoclonal antibodies were generated against F. psychrophilum (CSF 259-93) outer membrane preparations. Of these, FL43 was selected for assay development and shown to react with 67 F. psychrophilum isolates tested, but did not react with two strains of Flavobacterium columnare or one strain each of F. pectinovorum, F. aquatile, F. branchiophilum, and F. saccharophilum. An ELISA was developed using FL43 as the capture antibody and FL43 conjugated to horseradish peroxidase as the secondary detection antibody. The ELISA had a lower detection boundary of approximately 1.6 x 103 cfu/mL of F. psychrophilum in kidney tissue homogenates spiked with known bacterial concentrations. Asymptomatic coho salmon broodstock (n=50 samples) were sampled and showed 100% infection by ELISA analysis of kidney tissue and had an estimated bacterial load of 2.0 x 103 – 9.4 x 103 cfu/mL. Ovarian fluid was also collected from these same coho as well as rainbow trout broodstock; however, the ELISA proved unsuitable for ovarian fluid. A filtration based florescent antibody test (FAT) was subsequently developed by conjugating FL43 to Alexa Fluor®-488. This FAT was able to detect F. psychrophilum in 74% of ovarian fluid samples collected from coho salmon and 42% from rainbow trout. Interestingly, yellow-pigmented bacteria were isolated on culture plates from 100% of kidney and ovarian fluid samples. All yellow-pigmented colonies were tested by PCR and 100% of the coho and rainbow trout were confirmed positive for F. psychrophilum infection.

For more information, email the PI: Dr. Kenneth Cain

 August 7, 2012
Aug 072012
 

Kenneth CainAssociate Professor of Fish Pathology
Associate Director
Fishery Resources
Aquaculture Research Institute

 

(208) 885-7608
kcain@uidaho.edu

Biography

Dr. Kenneth Cain received a BS and MS in Fish and Wildlife from Michigan State University and a PhD in Animal Sciences from Washington State University. Ken’s research is focused on fish health and pathology. More specifically his primary research projects address fish immunology, aquaculture vaccine development, host-pathogen interactions, the development of new disease diagnostic tools, and antigen characterization/identification. In addition, Ken works in the area of aquaculture development for new species and is currently collaborating with the Kootenai Tribe of Idaho to develop captive rearing methods for Burbot (Lota lota). This species (a freshwater cod) is nearly extinct in Idaho and the methods developed at UI will be incorporated into a conservation aquaculture program to rehabilitate the remnant population in the Kootenai River. more info

CRISSP Research

A number of projects in my lab have investigated new and emerging diseases that create difficulties for species restoration. In some cases these pathogens can be considered invasive species if they are not endemic to this region. A good example of this is the parasite Myxobolus cerebralis, which causes whirling disease. The work that we are doing on vaccine development for coldwater disease also has implications for hatchery programs aimed at recovery of threatened steelhead and Coho salmon populations, as these species are very susceptible to this disease. Finally, the burbot program that has been ongoing since 2004 is directly related to CRISSP in that it is aimed at recovery of a small population in Idaho and is attempting to do this in lieu of listing this stock as an endangered species.

CRISSP Classes

(click on the links below for more information)

Fish 424: Fish Health Management

Fish 422: Concepts in Aquaculture

Fish 494: Seminar: Current Issues in Fish Health

 August 7, 2012