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Home / Equine Research Bank / Equine Vet J / Failure of serological testing for antigens A and C of Strep...
Equine veterinary journal2020; 53(1); 38-43; doi: 10.1111/evj.13276

Failure of serological testing for antigens A and C of Streptococcus equi subspecies equi to identify guttural pouch carriers.

Abstract: Serology is commonly used as a means of identifying horses that might be chronic and silent carriers of S. equi but its sensitivity is rarely examined. Objective: The study was designed to investigate the sensitivity of serological testing for antibodies against S. equi antigens A and C to detect guttural pouch carriers of S. equi. Methods: Retrospective clinical study. Methods: As part of routine surveillance and quarantine procedures horses arriving at a welfare charity quarantine unit were subject to both microbiological sampling of guttural pouches and also serological testing for antibodies directed at S. equi antigens A and C. Laboratory results and endoscopic findings were examined to determine associations between serological results and guttural pouch carriage of S. equi. Results: Of 287 included horses, 9 (3.1%) were found to be guttural pouch carriers. There was no significant association between serological status and guttural pouch carriage of S. equi Only one of the nine carriers (11%) was seropositive using a cut-off of OD ≥ 0.5, and only three of nine (33%) using a cut-off of OD ≥ 0.3. Conclusions: Horses examined in this study were new arrivals at a welfare centre rather than from a general, well-managed, equid population. As a retrospective clinical study, the laboratory test results could not be repeated for further confirmation. Conclusions: Caution is advised when relying on seronegativity to antigens A and C in order to discount the possibility of chronic carriage of S. equi in guttural pouches.
© 2020 The Authors. Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.
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Publication Date: 2020-05-20 PubMed ID: 32374892DOI: 10.1111/evj.13276Google Scholar: Lookup
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  • Journal Article

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The research article investigates the reliability of serological tests for antigens A and C in detecting horses that are chronic carriers of Streptococcus equi (S. equi) in their guttural pouches. The result of the study suggests caution in relying on seronegativity to antigens A and C to dismiss the possibility of chronic carriage of S. equi in horses’ guttural pouches.

Objective

  • The objective of the research was to examine the sensitivity of serological testing, a method that uses blood samples to detect specific antibodies, in detecting the antigens A and C of S. equi. These antigens are proteins of the bacteria that stimulate an immune response in the host body, in this case, horses.

Methods

  • The study method involved a retrospective clinical study that looked back on previously collected data.
  • Microbiological sampling of the guttural pouches and serological testing for antibodies aimed at the S. equi antigens A and C were done on horses as part of standard surveillance and quarantine procedures upon their arrival at a welfare charity quarantine unit.
  • The association between serological results and guttural pouch carriage of S. equi was investigated, i.e., looking for a relationship or correlation between the result of the blood test and the presence of bacteria within the guttural pouch of the horses.

Results

  • Out of 287 horses in the study, nine (3.1%) were identified as guttural pouch carriers of S. equi.
  • No significant correlation was found between the serological status and carriage of S. equi in the guttural pouch.
  • Only one out of nine carriers (11%) was seropositive, i.e., the blood test was positive for the antigens, at a cut-off point of OD ≥ 0.5. And only three out of nine (33%) were seropositive at a lesser cut-off OD ≥ 0.3.

Conclusion

  • The study concluded that the use of seronegativity, i.e., the absence of detectable levels of specific antibodies in the blood, as a method to dismiss guttural pouch carriers of S. equi should be approached with caution.
  • The researchers noted that the results could have been influenced by the fact that the horses were new arrivals at a welfare centre instead of from a general, well-managed, equid population.
  • As the research was a retrospective clinical study based on the investigation of previously collected data, laboratory test results could not be repeated for further confirmation.

Cite This Article

APA
Durham AE, Kemp-Symonds J. (2020). Failure of serological testing for antigens A and C of Streptococcus equi subspecies equi to identify guttural pouch carriers. Equine Vet J, 53(1), 38-43. https://doi.org/10.1111/evj.13276

Publication

Equine veterinary journal
ISSN: 2042-3306
NlmUniqueID: 0173320
Country: United States
Language: English
Volume: 53
Issue: 1
Pages: 38-43

Researcher Affiliations

Durham, Andy E
  • The Liphook Equine Hospital, Liphook, Hampshire, UK.
Kemp-Symonds, Jeremy
  • Bransby Horses, Bransby, Lincoln, UK.

MeSH Terms

  • Animals
  • Carrier State / diagnosis
  • Carrier State / veterinary
  • Horse Diseases / diagnosis
  • Horses
  • Retrospective Studies
  • Streptococcal Infections / diagnosis
  • Streptococcal Infections / veterinary
  • Streptococcus equi

References

This article includes 27 references
  1. Boyle AG, Timoney JF, Newton JR, Hines MT, Waller AS, Buchanan BR. Streptococcus equi infections in horses: guidelines for treatment, control, and prevention of strangles-revised consensus statement.. J Vet Intern Med 2018;32:633-47.
  2. Newton JR, Wood JL, Dunn KA, DeBrauwere MN, Chanter N. Naturally occurring persistent and asymptomatic infection of the guttural pouches of horses with Streptococcus equi.. Vet Rec 1997;140:84-90.
  3. Newton JR, Verheyen K, Talbot NC, Timoney JF, Wood JL, Lakhani KH. Control of strangles outbreaks by isolation of guttural pouch carriers identified using PCR and culture of Streptococcus equi.. Equine Vet J 2000;32:515-26.
  4. Weese JS, Jarlot C, Morley PS. Survival of Streptococcus equi on surfaces in an outdoor environment.. Can Vet J 2009;50:968-70.
  5. Durham AE, Hall YS, Kulp L, Underwood C. A study of the environmental survival of Streptococcus equi subspecies equi.. Equine Vet J 2018;50:861-4.
  6. Harris SR, Robinson C, Steward KF, Webb KS, Paillot R, Parkhill J. Genome specialization and decay of the strangles pathogen, Streptococcus equi, is driven by persistent infection.. Genome Res 2015;25:1360-71.
  7. Robinson C, Steward KF, Potts N, Barker C, Hammond TA, Pierce K. Combining two serological assays optimises sensitivity and specificity for the identification of Streptococcus equi subsp. equi exposure.. Vet J 2013;197:188-91.
  8. Waller AS. Strangles: taking steps towards eradication.. Vet Microbiol 2013;167:50-60.
  9. Kuwamoto Y, Anzai T, Wada R. Microplate sugar-fermentation assay distinguishes Streptococcus equi from other streptococci of Lancefield's group C.. J Equine Sci 2001;12:47-9.
  10. Bannister MF, Benson CE, Sweeney CR. Rapid species identification of group C streptococci isolated from horses.. J Clin Microbiol 1985;21:524-6.
  11. Cordoni G, Williams A, Durham A, Florio D, Zanoni RG, La Ragione RM. Rapid diagnosis of strangles (Streptococcus equi subspecies equi) using PCR.. Res Vet Sci 2015;102:162-6.
  12. Svonni E, Pringle J, Fernström L, Rydén A, Riihimäki M. Effectiveness of cleaning and disinfection procedures for endoscopes experimentally contaminated with S.equi (abstr.).. J Vet Intern Med 2018;32:872.
  13. Sheoran AS, Sponseller BT, Holmes MA, Timoney JF. Serum and mucosal antibody isotype responses to M-like protein (SeM) of Streptococcus equi in convalescent and vaccinated horses.. Vet Immunol Immunopathol 1997;59:239-51.
  14. Davidson A, Traub-Dargatz JL, Magnuson R, Hill A, Irwin V, Newton R. Lack of correlation between antibody titers to fibrinogen-binding protein of Streptococcus equi and persistent carriers of strangles.. J Vet Diagn Invest 2008;20:457-62.
  15. Gröndahl G, Båverud V, Ljung H, Melys V, Aspán A, Riihimäki M. Longitudinal observations of silent carriers of Streptococcus equi in a Swedish yard.. Equine Vet J 2015;47:22.
  16. Knowles EJ, Mair TS, Butcher N, Waller AS, Wood JL. Use of a novel serological test for exposure to Streptococcus equi subspecies equi in hospitalised horses.. Vet Rec 2010;166:294-7.
  17. Bowen M, Bates C, Morgan A, Bullard C, Telfer H, Housby Skeggs N. Serology for Streptococcus equi may not be valuable for detection of long-term carrier status in horses (abstr.).. Proceedings of the ECEIM Congress 2019.
  18. Sansonetti PJ. To be or not to be a pathogen: that is the mucosally relevant question.. Mucosal Immunol 2011;4:8-14.
  19. Buchanan RM, Mertins S, Wilson HL. Oral antigen exposure in extreme early life in lambs influences the magnitude of the immune response which can be generated in later life.. BMC Vet Res 2013;9:160.
  20. Cullinane A, Weld J, Osborne M, Nelly M, McBride C, Walsh C. Field studies on equine influenza vaccination regimes in thoroughbred foals and yearlings.. Vet J 2001;161:174-85.
  21. Halldorsdottir S, Lazary S, Gunnarsson E, Larsen HJ. Distribution of leucocyte antigens in Icelandic horses affected with summer eczema compared to non-affected horses.. Equine Vet J 1991;23:300-2.
  22. Chanter N, Talbot NC, Newton JR, Hewson D, Verheyen K. Streptococcus equi with truncated M-proteins isolated from outwardly healthy horses.. Microbiology (Reading, England) 2000;146(Pt 6):1361-9.
  23. Anzai T, Kuwamoto Y, Wada R, Sugita S, Kakuda T, Takai S. Variation in the N-terminal region of an M-like protein of Streptococcus equi and evaluation of its potential as a tool in epidemiologic studies.. Am J Vet Res 2005;66:2167-71.
  24. Kelly C, Bugg M, Robinson C, Mitchell Z, Davis-Poynter N, Newton JR. Sequence variation of the SeM gene of Streptococcus equi allows discrimination of the source of strangles outbreaks.. J Clin Microbiol 2006;44:480-6.
  25. Timoney JF, DeNegri R, Sheoran A, Forster N. Affects of N-terminal variation in the SeM protein of Streptococcus equi on antibody and fibrinogen binding.. Vaccine 2010;28:1522-7.
  26. Riihimaki M, Aspan A, Ljung H, Pringle J. Long term dynamics of a Streptococcus equi ssp equi outbreak, assessed by qPCR and culture and seM sequencing in silent carriers of strangles.. Vet Microbiol 2018;223:107-12.
  27. Pringle J, Venner M, Tscheschlok L, Bachi L, Riihimaki M. Long term silent carriers of Streptococcus equi ssp. equi following strangles; carrier detection related to sampling site of collection and culture versus qPCR.. Vet J 2019;246:66-70.
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