TWENTY-SECOND ANNUAL EASTERN FISH HEALTH WORKSHOP ROYAL PAVILLION RESORT, ATLANTIC BEACH, NC MARCH 18 - 20, 1997 Applicability of Non-Culture-Based Diagnostic Techniques: A Case Study of Furunculosis at a Salmonid Production Unit on the West Coast of Ireland Maura Hiney1, D. Gilroy1, D. Padley2, R. Powell2, and P. Smith1 1Fish Disease Group and 2Recombinant DNA Group, Department of Microbiology, University College Galway, Ireland Circumstantial evidence from many sources would suggest reservoir(s) of Aeromonas salmonicida, the bacterium associated with furunculosis, is external to its piscine host. Culture-based methods have been applied to the detection of A. salmonicida in the environment, however, there are many drawbacks to the application of culture-based methods to environmental samples, not least being the existence of non-culturable but viable cells in this type of sample and the inability of laboratory media to support the growth of the majority of environmental organisms. It has been suggested that non-culture-based pathogen detection (NCPD) techniques have the potential to improve the performance of both diagnosis and epizootiological studies of A. salmonicida and furunculosis. The ultimate test of the validity of these techniques is their ability to produce data that can be used to predict some aspect of furunculosis in the field. At present there exist few, if any, field studies of the predictive validity of such techniques. This paper reports investigations of the predictive validity of two NCPD techniques in the investigation of the epizootiology of furunculosis at a salmon production unit with a history of furunculosis. The NCPD techniques were a DNA/PCR system and an ELISA system, and environmental samples were also cultured on CBB agar. The existence of covert infections of A. salmonicida in fish at the production unit was monitored using the stress test. Correlation between the results obtained using each methodological approach and the ability of the NCPD techniques to predict the health status of fish at the unit will be discussed. Return to 22nd Annual Eastern Fish Health Workshop Return to Leetown Science Center Home Page