The use of ELISAs for monitoring exposure of pig herds to Brachyspira hyodysenteriae

Abstract

BackgroundSwine dysentery (SD), a mucohaemorrhagic diarrhoeal disease of pigs, results from infection of the large intestine with the spirochaete Brachyspira hyodysenteriae. ELISA systems using whole spirochaete cells (WC) and the B. hyodysenteriae outer membrane lipoprotein Bhlp29.7 previously have been established as potential diagnostic tools for SD. However, their true value in identifying infected herds remains unclear. The present study aimed to compare the performance of whole-cell and Bhlp29.7 based ELISAs in detecting specific immunoglobulin class IgG and IgM to B. hyodysenteriae in growing pigs, and additionally evaluated whether meat juice could serve as a source of specific antibodies.ResultsLevels of circulating IgG and IgM reacting with WC spirochaete preparations and recombinant Bhlp29.7 peaked 4-6 weeks post-infection in the experimentally challenged pigs, and remained elevated in the present study. In a cohort of pigs on an infected farm levels of antibody directed against both antigens showed a progressive increase with time. However, other than for the level of IgG against WC antigen, a significant increase in antibody levels also was observed in a cohort of pigs on a non-infected farm. In addition, assays using meat juice had 100% specificity and equivalent sensitivity to those based on serum, and likewise the best performance was achieved using the WC IgG ELISA.ConclusionsIgG ELISAs using either WC or Bhlp29.7 as plate-coating antigens were shown to be useful for monitoring the dynamics of B. hyodysenteriae infection in grower pigs. Of the two antigens, the WC preparation tended to give better discrimination between pigs from infected and non-infected farms. Testing of meat juice was shown to have potential for identifying infected herds.

Swine Dysentery

“…55,81 Enzyme-linked immunosorbent assay (ELISA)-based techniques for the detection of antibodies to lipopolysaccharide antigen are effective in differentiating B. hyodysenteriae infection from B. innocens ; however, these assays are serotype specific and therefore not universally applicable. 64 Recently, novel serologic assays have been developed with improved specificity to detect circulating antibodies against B. hyodysenteriae- specific outer membrane lipoproteins and may be useful for detecting infected pigs 75,114 ; however, these assays have not yet found broad application. Recent work has also suggested that ELISAs run on meat juices at slaughter may be useful in detecting herds infected with B. hyodysenteriae .…”

Brachyspira hyodysenteriae isolated from apparently healthy pig herds following an evaluation of a prototype commercial serological ELISA

“…Swine dysentery (SD) is endemic in many regions of the world. The disease typically presents 44 as a severe mucohaemorrhagic colitis mainly in grower and finisher pigs, although clinical 45 signs may be ameliorated or prevented by the use of antimicrobial agents (Hampson 2012). 46…”

Development of a serological ELISA using a recombinant protein to identify pig herds infected with Brachyspira hyodysenteriae

“…Enzyme-linked immunosorbent assays (ELISAs) have the potential to be used as rapid, sensitive and reproducible procedures for quantifying serum antibodies to B. hyodysenteriae, and providing indirect evidence of the current or past disease status of an individual pig, and/or of the herd of origin. ELISAs using sonicated whole cells or lipooligosaccharide (LOS) from B. hyodysenteriae as plate-coating antigens have been reported to be sensitive enough to allow detection of SD at a herd level, if sufficient pigs are tested (Joens et al, 1982;Wright et al, 1989;Smith et al, 1991;Song et al, 2012). Unfortunately, false-positive reactions hampered further development of these assays (La and Hampson, 2001).…”