Plasmacytoid leukaemia (PL) is a lymphoproliferative disorder that affects netpen-reared chinook salmon in British Columbia, Canada. The only diagnostic test for PL is histological evaluation of suspect fish. Monoclonal antibodies (MAbs) previously reported to react with tissues of PL-affected fish ...

Bacterial diseases of the gills of commercially reared salmonids in freshwater are common problems. They accounted for 18% of all diagnostic submissions to the Atlantic Veterinary College from commercial fish hatcheries. Definitive diagnosis is difficult because of the growth characteristics of the ...

A genomic library of Sarcocystis cruzi sporozoite DNA was constructed in bacteriophage lambda gt10. Recombinant phages containing insert DNA were selected by growth on Escherichia coli strain C600 hflA150. Of 14 clones examined, 11 contained DNA inserts ranging in size from approximately 1.45 kiloba...

The present study describes culture, virulence and antigenic characteristics of a Rickettsiales-like organism (RLO) associated with mortality in farmed Atlantic salmon in eastern Canada. Clinical disease was reproduced in naive Atlantic salmon parr by intraperitoneal i.p. inoculation with kidney hom...

Temperatures above 20 degrees C or below 9 degrees C interrupt the life cycle of the gill intracellular microsporidian parasite L. salmonae prior to sporogony, inhibiting the production of xenomas. This study intended to characterize this life-cycle failure. Juvenile rainbow trout were experimentall...

The objective of this study was to determine the agreement between ELISA tests conducted using three O. ostertagia antigens: crude adult worm, larval stage 4 (L4) excretory/secretory (ES) and adult ES. This study was carried out on 289 Holstein cows from five herds in Prince Edward Island and one he...

Immune response to fish microsporidia is still unknown and there are current research trying to elucidate the events involved in the immune response to this parasite. There is evidence suggesting the role of innate immune response and it is clear that adaptive immunity plays an essential part for el...

Although the mollusc immune system has been studied at the cellular level, the response to pathogens at gene expression level has not been thoroughly investigated. This study aimed to investigate the early molecular response of hemocytes of soft-shell clams, Mya arenaria, to Vibrio splendidus strain...

The objectives of the research were to compare the efficacy of ProVale yeast beta-glucan (beta-glucan) with that of a previously tested research-grade yeast beta-glucan preparation when administered as an intraperitoneal (IP) injection and to also pilot test the effectiveness of ProVale yeast beta-g...

Gene expression Studies have opened a tremendous field of investigation in biological research over the last decades. Expression of genes is most frequently quantified by real time PCR (RT-qPCR), as this method has proven to be highly sensitive. One of the critical steps, however, in comparing trans...

An immunofluorescent antibody test (IFAT) developed for the diagnosis for plasmacytoid leukemia was evaluated against histology under field conditions. Previously published results from a laboratory evaluation indicated that the IFAT had a much higher sensitivity than did histology. One hundred seve...

This study compared and contrasted the fate of the microsporidian Loma salmonae, a branchial pathogen of salmonids of the genus Oncorhynchus, upon exposure of (1) naive susceptible rainbow trout (RT) O. mykiss, (2) naive RT passively immunized with sera from RT previously exposed to L. salmonae, (3)...

Three exposure studies were conducted to assess whether oral exposure of naive rainbow trout to Loma salmonae spores at 2 temperatures (10 and 14.5 degrees C) provides protection against disease upon rechallenge with spores; to repeat the study at 14.5 degrees C using fish which had recovered from e...

A cross-sectional observational study was undertaken in Quebec dairy herds to evaluate regional and provincial prevalences of herds with gastrointestinal nematode (GIN) infections in lactating cows, and to determine risk factors associated with level of herd infection. The 5 most recently calved fir...

The intracellular microsporidian parasite Loma salmonae affects salmonids of the genus Oncorhynchus and is a significant cause of economic losses in pen-reared Chinook salmon (O. tshawytscha) in British Columbia. Loma salmonae infection is easily recognized by the xenomas that form in the gills, but...

Monthly bulk-tank milk samples were obtained from 415 Nova Scotia dairy herds in each of the months of July-September 1998 and tested using an indirect microtitre ELISA against a crude saline-extract, whole-worm Ostertagia ostertagi antigen. ELISA results (optical densities (ODs)) were consistent ac...

Two clones of 1.4 and 4.33 kilobase pairs (kbp) DNA inserts, were selected from a Sarcocystis cruzi sporozoite genomic library constructed in bacteriophage lambda gt10. These clones strongly hybridized with sporozoite and merozoite DNA and were evaluated as probes for detection of merozoite DNA in c...

An indirect Ostertagia ostertagi ELISA was used in late lactation milk samples from cows in confined and semi-confined dairy herds to determine if it could predict milk production response after endectocide treatment at calving. Holstein cows from 9 dairy farms from Prince Edward Island (PEI), 5 fro...

The present study was carried out to evaluate the relationship between milk optical density ratios (ODRs) from an indirect Ostertagia ostertagi ELISA, total milk IgG levels and milk production and then establish a correction factor to adjust ODR. Five hundred and sixty composite milk samples collect...

An indirect enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies against Ostertagia ostertagi using a crude adult worm antigen was evaluated using serum and milk samples from adult cows, as well as from bulk tank milk. Within and between plate repeatabilities were determined. In...

The general objective of this study was to evaluate a crude Ostertagia ostertagi antigen enzyme-linked immunosorbent assay (ELISA) for monitoring gastrointestinal parasites in lactating dairy cattle. A longitudinal study of gastrointestinal parasites in lactating dairy cows was carried out in 38 her...