Development and evaluation of an immunochromatographic strip for detection of Streptococcus suis type 2 antibody

J Vet Diagn Invest. 2007 Jul;19(4):355-61. doi: 10.1177/104063870701900403.

Abstract

In this study, an immunochromatographic strip (ICS) was developed for the detection of antibody against Streptococcus suis serotype 2 (SS2). Colloidal gold particles labeled with staphylococcal protein A (SPA), which can bind to the F(C) fragment of mammalian immunoglobulin, were used as the detector reagent. The capsular polysaccharide (CPS) of SS2 and affinity-purified IgG from a healthy naive pig were immobilized on test and control regions of a nitrocellulose membrane, respectively. The ICS was used to 1) detect anti-CPS antibody in 14 sera taken from 4 SS2-infected pigs, 24 sera from pigs hyperimmunized with SS2, and 68 sera from pigs inoculated or infected with bacteria other than SS2; 2) determine anti-CPS antibody titers of 20 positive sera for comparison with enzyme-linked immunosorbent assay (ELISA); and 3) detect anti-CPS antibody in 226 clinical sera taken from diseased pigs also for comparison with ELISA. An ELISA used as a reference test determined the specificity and sensitivity of the ICS to be 97.1% and 86.3%, respectively. There was excellent agreement between the results obtained by ELISA and the ICS (kappa = 0.843). Additionally, there was strong agreement between the results of bacterial isolation from pig tonsils and ICS test (kappa = 0.658). Because it is rapid and easy to use, the test is suitable for the serological surveillance of SS2 at farms.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Bacterial / isolation & purification*
  • Immunoassay / instrumentation
  • Immunoassay / methods
  • Immunoassay / veterinary*
  • Reagent Strips*
  • Sensitivity and Specificity
  • Streptococcal Infections / diagnosis
  • Streptococcal Infections / immunology
  • Streptococcal Infections / microbiology
  • Streptococcal Infections / veterinary
  • Streptococcus suis / immunology*
  • Swine / immunology
  • Swine / microbiology*
  • Swine Diseases / diagnosis
  • Swine Diseases / immunology
  • Swine Diseases / microbiology

Substances

  • Antibodies, Bacterial
  • Reagent Strips