Development of an Enzyme Linked Immunosorbant Assay (Elisa) as a Diagnostic Tool for the Detection and Quantification of Loma salmonae

Description

Loma salmonae (Microsporidia) is the causative agent of microsporidial gill disease (MGD) in several members of the Oncorhynchus genus, in particular farmed Chinook salmon (O. tshawytscha) and coho salmon (O. kisutch). Infection results in the formation of cyst-like structures called xenomas in the gill. Mature xenomas rupture, provoking a strong inflammatory reaction, which can result in severe branchitis and potentially death by asphyxia . In addition to the direct losses associated with mortalities, L. salmonae infection has been shown to impact growth and feed conversion rates, reducing productivity and resulting in additional economic impact to Chinook producers in British Columbia. Current detection and diagnosis of L. salmonae is either by direct gill examination, polymerase chain reaction (PCR) or histological examination of stained gill tissue. L. salmonae DNA can be detected in gill tissue by PCR as early as 2 weeks post exposure (PE) in rainbow trout (RBT). Although PCR analysis is very sensitive, allowing early detection, it does not provide quantitative data of infection severity. Enzyme Linked Immunosorbant Assay (ELISA) utilizes highly sensitive and specific antibodies for pathogen detection. In addition, ELISA also provides quantitative data, which will allow intensity of infections to be measured. The use of ELISA will provide advantages over the current diagnostic methods for L. salmonae in Chinook. ELISA will allow early detection and quantification of infection before xenomas are mature, allowing fish farmers to make timely management decisions. ELISA will also be a valuable research tool, reducing both the time and costs associated with measuring the effects of experimental treatments on prevalence and/or intensity of infections.

Program Name

Aquaculture Collaborative Research and Development Program (ACRDP)

Year(s)

2005 - 2006

Ecoregion(s)

Pacific: Vancouver Island West Coast

Principal Investigator(s)

Simon Jones
Email: JonesS@pac.dfo-mpo.gc.ca