Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
The Antiphagocytic Activity of SeM of Streptococcus equi Requires Capsule.
Abstract: Resistance to phagocytosis is a crucial virulence property of Streptococcus equi (Streptococcus equi subsp. equi; Se), the cause of equine strangles. The contribution and interdependence of capsule and SeM to killing in equine blood and neutrophils were investigated in naturally occurring strains of Se. Strains CF32, SF463 were capsule and SeM positive, strains Lex90, Lex93 were capsule negative and SeM positive and strains Se19, Se1-8 were capsule positive and SeM deficient. Phagocytosis and killing of Se19, Se1-8, Lex90 and Lex93 in equine blood and by neutrophils suspended in serum were significantly (P ≤ 0.02) greater compared to CF32 and SF463. The results indicate capsule and SeM are both required for resistance to phagocytosis and killing and that the anti-phagocytic property of SeM is greatly reduced in the absence of capsule.
Publication Date: 2014-06-25 PubMed ID: 25013359PubMed Central: PMC4090359DOI: 10.1294/jes.25.53Google Scholar: Lookup The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- 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.
This research study investigates how Streptococcus equi, a bacterium responsible for a severe equine respiratory disease known as strangles, resists being killed by the immune system. The study finds the bacterium’s resistance to phagocytosis – the process by which cells of the immune system engulf and destroy pathogens – is dependent on two bacterial components: a capsule and a molecule named SeM.
Objectives
- The study primarily aimed to explore the roles and interdependence of the capsule and SeM in resisting destruction by the immune system in equine blood and neutrophils (a type of immune cell).
- It also compared the rate of phagocytosis and killing of different strains of Streptococcus equi that vary in their possession of the capsule and SeM.
Methodology
- The research involved multiple strains of the Streptococcus equi bacterium. Some were positive for both capsule and SeM (strains CF32, SF463), some lacked capsule but had SeM (strains Lex90, Lex93) and others had the capsule but were SeM deficient (strains Se19, Se1-8).
- The degree of phagocytosis and killing of these different strains in equine blood and by neutrophils was examined and compared.
Findings
- Greater phagocytosis and killing occurred in the Se19, Se1-8, Lex90, and Lex93 strains in both equine blood and neutrophils, compared to the CF32 and SF463 strains.
- Notably, this demonstrates that both SeM and the capsule are necessary for the bacterium to resist phagocytosis and killing by the immune system.
- Furthermore, it indicates that the protective property of SeM against phagocytosis is greatly diminished if the bacterium lacks the capsule.
Conclusion
- In conclusion, the findings indicate that the capsule and SeM in Streptococcus equi are both vital for resisting destruction by the immune system.
- This work provides valuable insights into the virulence of this bacterium, which could inform potential therapeutic strategies for equine strangles.
Cite This Article
APA
Timoney JF, Suther P, Velineni S, Artiushin SC.
(2014).
The Antiphagocytic Activity of SeM of Streptococcus equi Requires Capsule.
J Equine Sci, 25(2), 53-56.
https://doi.org/10.1294/jes.25.53 Publication
Researcher Affiliations
- Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY 40546-0099, USA.
- Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY 40546-0099, USA.
- Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY 40546-0099, USA.
- Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY 40546-0099, USA.
References
This article includes 17 references
- Anzai T, Timoney JF, Kuwamoto Y, Fujita Y, Wada R, Inoue T. In vivo pathogenicity and resistance to phagocytosis of Streptococcus equi strains with different levels of capsule expression.. Vet Microbiol 1999 Jul 1;67(4):277-86.
- Boschwitz JS, Timoney JF. Inhibition of C3 deposition on Streptococcus equi subsp. equi by M protein: a mechanism for survival in equine blood.. Infect Immun 1994 Aug;62(8):3515-20.
- Chanter N, Collin NC, Mumford JA. Resistance of Streptococcus equi in vitro to equine polymorphonuclear leucocytes. Proceedings of seventh International Conference on Equine Infectious Diseases pp. 201–205.
- Galán JE, Timoney JF. Immunologic and genetic comparison of Streptococcus equi isolates from the United States and Europe.. J Clin Microbiol 1988 Jun;26(6):1142-6.
- Jean-François MJ, Poskitt DC, Turnbull SJ, Macdonald LM, Yasmeen D. Protection against Streptococcus equi infection by monoclonal antibodies against an M-like protein.. J Gen Microbiol 1991 Sep;137(9):2125-33.
- Li W, Fiala S, Gibson N, Timoney JF, Cairns R, Acree WM, Chu HJ. Efficacy of a modified live Streptococcus equi vaccine in an equine experimental model. Proceedings of eight International Conference on Equine Infectious Diseases pp. 357–358.
- Meehan M, Lynagh Y, Woods C, Owen P. The fibrinogen-binding protein (FgBP) of Streptococcus equi subsp. equi additionally binds IgG and contributes to virulence in a mouse model.. Microbiology (Reading) 2001 Dec;147(Pt 12):3311-22.
- Sedgwick AD, Morris T, Russell BA, Lees P. Single step purification procedure for the rapid separation of equine leucocytes.. Vet Res Commun 1986 Nov;10(6):445-52.
- Timoney JF. Strangles.. Vet Clin North Am Equine Pract 1993 Aug;9(2):365-74.
- Timoney JF, Galan JE. The protective response of the horse to an avirulent strain of Streptococcus equi. Recent Advances in Streptococci and Streptococcal Diseases: Proceedings of the ninth Lancefield International symposium on Streptococci and Streptococcal Diseases pp. 294–295.
- Timoney JF, Guan M. Characterisation of murine monoclonal antibodies recognising opsonic, mouse-protective, chaining and mucosally relevant epitopes on the M protein of Streptococcus equi subspecies equi.. Res Vet Sci 1996 Jan;60(1):76-81.
- Timoney JF, Trachman J. Immunologically reactive proteins of Streptococcus equi.. Infect Immun 1985 Apr;48(1):29-34.
- Timoney JF, Artiushin SC, Boschwitz JS. Comparison of the sequences and functions of Streptococcus equi M-like proteins SeM and SzPSe.. Infect Immun 1997 Sep;65(9):3600-5.
- Timoney JF, Wang J, Artiushin S, Sheoran A, Nally J, Kumar P. Virulence and immunogenicity of a clone of Streptococcus equi in which expression of SeM is blocked by Tn916 mutagenesis. Streptococci and Streptococcal Diseases Entering the New Millinium pp. 699–702.
- Timoney JF, Yang J, Liu J, Merant C. IdeE reduces the bactericidal activity of equine neutrophils for Streptococcus equi.. Vet Immunol Immunopathol 2008 Mar 15;122(1-2):76-82.
- Tiwari R, Qin A, Artiushin S, Timoney JF. Se18.9, an anti-phagocytic factor H binding protein of Streptococcus equi.. Vet Microbiol 2007 Mar 31;121(1-2):105-15.
- Whitnack E, Bisno AL, Beachey EH. Hyaluronate capsule prevents attachment of group A streptococci to mouse peritoneal macrophages.. Infect Immun 1981 Mar;31(3):985-91.
Citations
This article has been cited 8 times.- Kerstens J, Durmus B, Lambrecht S, Baar I, Ieven MM, Van Der Zijden T, Parizel PM, Menovsky T, Lammens MMY, Jorens PG. Meningoencephalitis with Streptococcus equi Subspecies equi Leading to a Dural Arteriovenous Fistula. Case Rep Neurol Med 2021;2021:9898364.
- 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 Mar;32(2):633-647.
- He L, Khine NO, Song J, Loubière C, Butaye P. Geographic diversity of the Streptococcus equi subsp. equi accessory genome: implications for vaccines and global surveillance. Front Vet Sci 2025;12:1721958.
- Wan J, Weldon E, Ganser G, Morris ERA, Hughes EV, Bordin AI, Heine PA, Hust M, Cohen ND, Gill JJ, Liu M. Immunogenic Streptococcus equi cell surface proteins identified by ORFeome phage display. mSphere 2025 Dec 23;10(12):e0062625.
- Seeger MG, de Vargas APC, Vogel FSF, Cargnelutti JF. Streptococcus equi subsp. equi isolated from horses in Southern Brazil: molecular and phenotypic analyses. Braz J Microbiol 2025 Dec;56(4):2987-2996.
- Abdul-Latif SAK, Yousif AA. Molecular study of Streptococcus equi isolated from horses with strangles in Iraq. Open Vet J 2025 Feb;15(2):731-737.
- Soliman R, Yousef M, Gelil SA, Aboul-Ella H. Development of novel Streptococcus equi vaccines with an assessment of their immunizing potentials and protective efficacies. BMC Vet Res 2024 May 3;20(1):173.
- Turner CE, Bubba L, Efstratiou A. Pathogenicity Factors in Group C and G Streptococci. Microbiol Spectr 2019 May;7(3).
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
