Neorickettsia risticii surface-exposed proteins: proteomics identification, recognition by naturally-infected horses, and strain variations.
Abstract: Neorickettsia risticii is the Gram-negative, obligate, and intracellular bacterial pathogen responsible for Potomac horse fever (PHF): an important acute systemic disease of horses. N. risticii surface proteins, critical for immune recognition, have not been thoroughly characterized. In this paper, we identified the 51-kDa antigen (P51) as a major surface-exposed outer membrane protein of older and contemporary strains of N. risticii through mass spectrometry of streptavidin-purified biotinylated surface-labeled proteins. Western blot analysis of sera from naturally-infected horses demonstrated universal and strong recognition of recombinant P51 over other Neorickettsia recombinant proteins. Comparisons of amino acid sequences for predicted secondary structures of P51, as well as Neorickettsia surface proteins 2 (Nsp2) and 3 (Nsp3) among N. risticii strains from horses with PHF during a 26-year period throughout the United States revealed that the majority of variations among strains were concentrated in regions predicted to be external loops of their β-barrel structures. Large insertions or deletions occurred within a tandem-repeat region in Ssa3. These data demonstrate patterns of geographical association for P51 and temporal associations for Nsp2, Nsp3, and Ssa3, indicating evolutionary trends for these Neorickettsia surface antigen genes. This study showed N. risticii surface protein population dynamics, providing groundwork for designing immunodiagnostic targets for PHF.
Publication Date: 2011-06-02 PubMed ID: 21635728PubMed Central: PMC3127766DOI: 10.1186/1297-9716-42-71Google 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
- Research Support
- N.I.H.
- Extramural
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 is about the proteins on the surface of the bacterium Neorickettsia risticii, the pathogen causing Potomac horse fever (PHF) in horses. The research focused on identifying these proteins, examining how they are recognized by infected horses, and analyzing differences in strains.
Identification of Surface-Exposed Proteins
- The research explored the proteins found on the surface of N.risticii bacteria cells. These proteins play a crucial role in the immune recognition in horses.
- Through mass spectrometry of proteins tagged with streptavidin-purified biotin, the 51-kDA antigen (P51) was identified as a significant protein present on the outer membrane of the bacteria.
- This protein was found in both older and contemporary strains of the bacterium, highlighting its importance and persistency.
Immunological Response
- Further testing involved assessing the reaction of sera from naturally infected horses to the recombinant P51 compared to other Neorickettsia recombinant proteins.
- Western Blot analysis demonstrated a strong and universal recognition of the recombinant P51 by the horse’s immune system. This indicates the P51 protein critically contributes to the horse’s immune response to the infection.
Strain Variations and Analysis
- The study also compared the amino acid sequences of P51 and other surface proteins (Nsp2 and Nsp3) across N.risticii strains from horses suffering from PHF during a 26-year period throughout the United States.
- The comparison revealed that most variations among the strains were concentrated in regions predicted to be the external loops of their β-barrel structures.
- Significant changes or deletions were detected within a tandem-repeat region in Ssa3, another important surface protein.
Implications of the Research
- The research showed how different strains of the bacterium have evolved over time.
- There were geographical associations found for P51 patterns and temporal associations for Nsp2, Nsp3, and Ssa3.
- The patterns reveal the evolution of the surface antigen genes for the bacteria, providing a deeper understanding of how the pathogens evolve, and may assist in the development of more targeted therapies in the future.
- Overall, this understanding of N. risticii surface protein dynamics provides a groundwork that can contribute to designing effective immunodiagnostic targets for Potomac horse fever.
Cite This Article
APA
Gibson KE, Pastenkos G, Moesta S, Rikihisa Y.
(2011).
Neorickettsia risticii surface-exposed proteins: proteomics identification, recognition by naturally-infected horses, and strain variations.
Vet Res, 42(1), 71.
https://doi.org/10.1186/1297-9716-42-71 Publication
Researcher Affiliations
- Department of Veterinary Biosciences, The Ohio State University College of Veterinary Medicine, 1925 Coffey Rd, Columbus, OH 43210, USA. rikihisa.1@osu.edu.
MeSH Terms
- Anaplasmataceae Infections / microbiology
- Anaplasmataceae Infections / veterinary
- Animals
- Antigens, Bacterial / chemistry
- Antigens, Bacterial / genetics
- Antigens, Bacterial / immunology
- Bacterial Outer Membrane Proteins / chemistry
- Bacterial Outer Membrane Proteins / genetics
- Bacterial Outer Membrane Proteins / immunology
- Blotting, Western / veterinary
- Horse Diseases / microbiology
- Horses
- Neorickettsia risticii / genetics
- Neorickettsia risticii / immunology
- Polymerase Chain Reaction / veterinary
- Protein Structure, Secondary
- Proteomics
- Recombinant Proteins / chemistry
- Recombinant Proteins / genetics
- Recombinant Proteins / immunology
- Sequence Alignment / veterinary
Grant Funding
- R01AI047885 / NIAID NIH HHS
- T32 RR0070703 / NCRR NIH HHS
- T35 RR021310 / NCRR NIH HHS
References
This article includes 65 references
Citations
This article has been cited 9 times.- Perles L, Barreto WTG, Macedo GC, Herrera HM, Machado RZ, André MR. Neorickettsia sp. in coatis (Nasua nasua) in Brazil.. Rev Bras Parasitol Vet 2023;32(3):e006623.
- Thirumalapura NR, Livengood J, Beeby J, Wang W, Goodrich EL, Goodman LB, Erol E, Tewari D. Improved molecular detection of Neorickettsia risticii with a duplex real-time PCR assay in the diagnosis of Potomac horse fever.. J Vet Diagn Invest 2023 Jan;35(1):62-66.
- Budachetri K, Lin M, Yan Q, Chien RC, Hostnik LD, Haanen G, Leclère M, Waybright W, Baird JD, Arroyo LG, Rikihisa Y. Real-Time PCR Differential Detection of Neorickettsia findlayensis and N. risticii in Cases of Potomac Horse Fever.. J Clin Microbiol 2022 Jul 20;60(7):e0025022.
- Uzal FA, Arroyo LG, Navarro MA, Gomez DE, Asín J, Henderson E. Bacterial and viral enterocolitis in horses: a review.. J Vet Diagn Invest 2022 May;34(3):354-375.
- Teymournejad O, Lin M, Bekebrede H, Kamr A, Toribio RE, Arroyo LG, Baird JD, Rikihisa Y. Isolation and Molecular Analysis of a Novel Neorickettsia Species That Causes Potomac Horse Fever.. mBio 2020 Feb 25;11(1).
- McKenzie HC, Funk RA, Trager L, Werre SR, Crisman M. Immunogenicity of Potomac horse fever vaccine when simultaneously co-administered with rabies vaccine in a multivalent vaccine or as two monovalent vaccines at separate sites.. Equine Vet J 2019 Nov;51(6):774-778.
- Lin M, Bachman K, Cheng Z, Daugherty SC, Nagaraj S, Sengamalay N, Ott S, Godinez A, Tallon LJ, Sadzewicz L, Fraser C, Dunning Hotopp JC, Rikihisa Y. Analysis of complete genome sequence and major surface antigens of Neorickettsia helminthoeca, causative agent of salmon poisoning disease.. Microb Biotechnol 2017 Jul;10(4):933-957.
- Fischer K, Tkach VV, Curtis KC, Fischer PU. Ultrastructure and localization of Neorickettsia in adult digenean trematodes provides novel insights into helminth-endobacteria interaction.. Parasit Vectors 2017 Apr 13;10(1):177.
- Xiong Q, Bekebrede H, Sharma P, Arroyo LG, Baird JD, Rikihisa Y. An Ecotype of Neorickettsia risticii Causing Potomac Horse Fever in Canada.. Appl Environ Microbiol 2016 Oct 1;82(19):6030-6.
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
