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

Abstract

Development of a serological ELISA using a recombinant protein to identify pig herds infected with brachyspira hyodysenteriae, The Veterinary Journal (2015), http://dx.doi.org/doi: 10.1016/j.tvjl.2015.08.021. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.  The new test should be useful for screening herds for evidence of swine dysentery 21 Abstract 22Brachyspira hyodysenteriae is an anaerobic spirochaete that can induce swine 23 dysentery (SD), a severe mucohaemorrhagic colitis in grower and fattener pigs. The aim of this 24 study was to develop a serological ELISA for use as a screening method to detect evidence of 25 herd infection. Bioinformatic analysis of the complete genome sequence of strain WA1 was 26 used to identify genes predicted to encode outer membrane proteins. Twenty candidate genes 27 were expressed in an Escherichia coli mediated system, and purified as histidine-tagged 28 recombinant proteins. Selection of optimal antigens under different conditions was conducted 29 using Western blot and ELISA with a range of pig sera from infected and uninfected pigs. 30From this analysis, three recombinant proteins were selected as being most suitable for use as 31antigens. These antigens then were tested under optimized conditions in an indirect ELISA 32 detecting IgG2 using 1551 sera from healthy pigs at slaughter, comprising 896 from 18 herds 33 considered to be free from SD and 655 from 12 infected herds. 34 35Using a cut-off value for positivity of the mean plus five standard deviations of the 36 mean for the negative sera, the best overall results were obtained with the ELISA using antigen 37 H114, which was 100% specific and 91.7% sensitive at detecting the reported status of the 38herds. This new ELISA should be a useful adjunct for detecting and monitoring the status of 39 herds with respect to the presence of B. hyodysenteriae, and should prove useful for 40 understanding the dynamics of infection in herds where the spirochaete is present. 41

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

“…64 65 Enzyme-linked immunosorbent assays (ELISAs) have the potential to be used for quantifying 66 serum antibodies to pathogens, and hence providing indirect evidence of past exposure to the 67 pathogen. As a consequence they are very useful in routine screening of apparently healthy 68 animals at the abattoir to assess the likely status of the herd of origin, particularly where the 69 be widespread amongst B. hyodysenteriae strains and to have potential to be used as an ELISA 83 antigen to detect infected herds (Song et al 2015). In the current study a prototype test using 84 H114 developed by Prionics AG (Priocheck ® Brachyspira porcine Ab ELISA) was tested on 85 sera from pigs in 30 herds with or without a history of having SD.…”

Experimental natural transmission (seeder pig) models for reproduction of swine dysentery

“…Several prototype B . hyodysenteriae enzyme-linked immunosorbent assays (ELISA) have been developed to detect antibodies circulating in sera [ 32 – 34 ]. An Australian field study [ 33 ] showed that seroprevalence varies from <5% to 100% in both reported SD-negative and reported SD-positive farms indicating that serum profiling is most suited for herd-level investigations.…”

Experimental Infection of Pigs with a ST 245 Brachyspira hyodysenteriae Isolated from an Asymptomatic Pig in a Herd with No History of Swine Dysentery

“…Genetic variation and marked differences in antigenic proteins are significant limitations for development of a globally applicable serological test [36]. Some studies using recombinant proteins have been carried out to develop a serological test that would be an important tool for detecting B. hyodysenteriae positive herds without clinical signs of SD [21,37].…”