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Zu H, Sun R, Li J, Guo X, Wang M, Guo W, Wang X. Development of a Real-Time Recombinase-Aided Amplification Method for the Rapid Detection of Streptococcus equi subsp. equi. Microorganisms 2024; 12:777. [PMID: 38674721 PMCID: PMC11052427 DOI: 10.3390/microorganisms12040777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 03/09/2024] [Accepted: 03/10/2024] [Indexed: 04/28/2024] Open
Abstract
Streptococcus equi subspecies equi (S. equi) is the causative pathogen of strangles in horses, donkeys, and other equine animals. Strangles has spread globally and causes significant losses to the horse industry. In response to the urgent need for effective disease control, this study introduces a novel nucleic acid diagnostic method known as a real-time recombinase-assisted amplification (RAA) assay, developed based on the eqbE gene, for the rapid detection of S. equi nucleic acid. The real-time RAA method employs specifically designed probes and primers targeting the eqbE gene, enhancing the overall specificity and sensitivity of the detection. After efficiency optimization, this real-time RAA method can detect 10 or more copies of nucleic acid within 20 min. The method demonstrates high specificity for S. equi and does not cross-react with other clinically relevant pathogens. Real-time RAA diagnostic performance was evaluated using 98 nasal swab samples collected from horses and compared with the real-time PCR detection method. Results revealed that 64 and 65 samples tested positive for S. equi using real-time RAA and real-time PCR, respectively. The overall agreement between the two assays was 96.94% (95/98), with a kappa value of 0.931 (p < 0.001). Further linear regression analysis indicated a significant correlation in the detection results between the two methods (R2 = 0.9012, p < 0.0001), suggesting that the real-time RAA assay exhibits a detection performance comparable to that of real-time PCR. In conclusion, the real-time RAA assay developed here serves as a highly specific and reliable diagnostic tool for the detection of S. equi in equine samples, offering a potential alternative to real-time PCR methods. In conclusion, the real-time RAA nucleic acid diagnostic method, based on the eqbE gene, offers rapid and accurate diagnosis of S. equi, with the added advantage of minimal equipment requirements, thus contributing to the efficient detection of strangles in horses.
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Affiliation(s)
- Haoyu Zu
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China (M.W.)
| | - Rongkuan Sun
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China (M.W.)
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Jiaxin Li
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China (M.W.)
| | - Xing Guo
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China (M.W.)
| | - Min Wang
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China (M.W.)
| | - Wei Guo
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China (M.W.)
- Institute of Western Agriculture, The Chinese Academy of Agricultural Sciences, Changji 831100, China
| | - Xiaojun Wang
- State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China (M.W.)
- Institute of Western Agriculture, The Chinese Academy of Agricultural Sciences, Changji 831100, China
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2
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Shi L, Hu J, Jin Z. Dynamics analysis of strangles with asymptomatic infected horses and long-term subclinical carriers. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2023; 20:18386-18412. [PMID: 38052563 DOI: 10.3934/mbe.2023817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
Strangles is one of the most prevalent horse diseases globally. The infected horses may be asymptomatic and can still carry the infectious pathogen after it recovers, which are named asymptomatic infected horses and long-term subclinical carriers, respectively. Based on these horses, this paper establishes a dynamical model to screen, measure, and model the spread of strangles. The basic reproduction number $ \mathcal{R}_0 $ is computed through a next generation matrix method. By constructing Lyapunov functions, we concluded that the disease-free equilibrium is globally asymptotically stable if $ \mathcal{R}_0 < 1 $, and the endemic equilibrium exits uniquely and is globally asymptotically stable if $ \mathcal{R}_0 > 1 $. For example, while studying a strangles outbreak of a horse farm in England in 2012, we computed an $ \mathcal{R}_0 = 0.8416 $ of this outbreak by data fitting. We further conducted a parameter sensitivity analysis of $ \mathcal{R}_0 $ and the final size by numerical simulations. The results show that the asymptomatic horses mainly influence the final size of this outbreak and that long-term carriers are connected to an increased recurrence of strangles. Moreover, in terms of the three control measures implemented to control strangles(i.e., vaccination, implementing screening regularly and isolating symptomatic horses), the result shows that screening is the most effective measurement, followed by vaccination and isolation, which can provide effective guidance for horse management.
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Affiliation(s)
- Lusha Shi
- Complex Systems Research Center, Shanxi University, Taiyuan 030006, China
- Shanxi Key Laboratory of Mathematical Techniques and Big Data Analysis on Disease Control and Prevention, Shanxi University, Taiyuan 030006, China
- Key Laboratory of Complex Systems and Data Science of Ministry of Education, Shanxi University, Taiyuan 030006, China
- School of Mathematical Sciences, Shanxi University, Taiyuan 030006, China
| | - Jianghong Hu
- Complex Systems Research Center, Shanxi University, Taiyuan 030006, China
- Shanxi Key Laboratory of Mathematical Techniques and Big Data Analysis on Disease Control and Prevention, Shanxi University, Taiyuan 030006, China
- Key Laboratory of Complex Systems and Data Science of Ministry of Education, Shanxi University, Taiyuan 030006, China
| | - Zhen Jin
- Complex Systems Research Center, Shanxi University, Taiyuan 030006, China
- Shanxi Key Laboratory of Mathematical Techniques and Big Data Analysis on Disease Control and Prevention, Shanxi University, Taiyuan 030006, China
- Key Laboratory of Complex Systems and Data Science of Ministry of Education, Shanxi University, Taiyuan 030006, China
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3
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Boyle AG. Streptococcus equi Subspecies equi. Vet Clin North Am Equine Pract 2023; 39:115-131. [PMID: 36737294 DOI: 10.1016/j.cveq.2022.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Strangles, caused by the bacteria Streptococcus equi subsp equi, is a highly contagious disease of equids classically characterized by a high fever and enlarged lymph nodes of the head. Diagnostic sampling depends on the stage of the disease. The goal of treating strangles is to control transmission and to eliminate infection while providing future host immunity. Daily temperature checking and isolation of febrile horses is the key to controlling outbreaks. Eradication of this disease will not be possible until S equi carriers are eliminated from the equine population.
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Affiliation(s)
- Ashley G Boyle
- Department of Clinical Studies, New Bolton Center, University of Pennsylvania, School of Veterinary Medicine, 382 West Street Road, Kennett Square, PA 19348, USA.
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4
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Chhabra D, Bhatia T, Goutam U, Manuja A, Kumar B. Strangles in equines: An overview. Microb Pathog 2023; 178:106070. [PMID: 36924902 DOI: 10.1016/j.micpath.2023.106070] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 03/13/2023] [Accepted: 03/14/2023] [Indexed: 03/16/2023]
Abstract
Strangles, caused by Streptococcus equi subspecies equi, is a highly infectious respiratory disease affecting horses and other equines. The disease is economically important and compromises the productivity of equine farm significantly. The disease is characterized by pyrexia, mucopurulent nasal discharge, and abscess formation in the lymph nodes of the head and neck of horses. The disease transmission occurs either directly by coming in contact with infectious exudates or indirectly via fomite transmission. Besides this, carrier animals are the primary and most problematic source of disease infection. The organism not only initiates outbreaks but also makes the control and prevention of the disease difficult. The diagnosis of strangles is best done by isolating and characterizing the bacteria from nasal discharge, pus from abscesses, and lymphoid tissues or by using PCR. ELISA can also be used to detect serum protein M (SeM) antibodies for diagnosis. The most popular treatment for strangles is with penicillin; however, the treatment is affected by the stage, feature and severity of the disease. Prevention and control of strangles can be achieved through vaccination and good hygiene practices. Basically, this review describes the global prevalence of S. equi, as well as general aspects of the disease, like pathogenesis, diagnosis, treatment, prevention, control and management of the disease.
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Affiliation(s)
- Dharvi Chhabra
- ICAR-National Research Centre on Equines, Hisar, 125001, India
| | - Tanvi Bhatia
- ICAR-National Research Centre on Equines, Hisar, 125001, India
| | - Umesh Goutam
- Lovely Professional University, Phagwara, Punjab, India
| | - Anju Manuja
- ICAR-National Research Centre on Equines, Hisar, 125001, India.
| | - Balvinder Kumar
- ICAR-National Research Centre on Equines, Hisar, 125001, India.
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5
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Voluntary Biosurveillance of Streptococcus equi Subsp. equi in Nasal Secretions of 9409 Equids with Upper Airway Infection in the USA. Vet Sci 2023; 10:vetsci10020078. [PMID: 36851382 PMCID: PMC9962190 DOI: 10.3390/vetsci10020078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/16/2023] [Accepted: 01/18/2023] [Indexed: 01/22/2023] Open
Abstract
This study aimed to describe selected epidemiological aspects of horses with acute onset of fever and respiratory signs testing qPCR-positive for S. equi and to determine the effect of vaccination against S. equi on qPCR status. Horses with acute onset of fever and respiratory signs from all regions of the United States were included in a voluntary biosurveillance program from 2008 to 2020 and nasal secretions were tested via qPCR for S. equi and common respiratory viruses. A total of 715/9409 equids (7.6%) tested qPCR-positive for S. equi, with 226 horses showing coinfections with EIV, EHV-1, EHV-4, and ERBV. The median age for the S. equi qPCR-positive horses was 8 ± 4 years and there was significant difference when compared to the median age of the S. equi qPCR-negative horses (6 ± 2 years; p = 0.004). Quarter Horse, Warmblood, and Thoroughbred were the more frequent breed in this horse population, and these breeds were more likely to test qPCR-positive for S. equi compared to other breeds. There was not statistical difference for sex between S. equi qPCR-positive and qPCR-negative horses. Horses used for competition and ranch/farm use were more likely to test qPCR-positive for S. equi (p = 0.006). Horses that tested S. equi qPCR-positive were more likely to display nasal discharge, fever, lethargy, anorexia, and ocular discharge compared to horses that tested S. equi qPCR-negative (p = 0.001). Vaccination against S. equi was associated with a lower frequency of S. equi qPCR-positive status.
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6
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Rotinsulu DA, Ewers C, Kerner K, Amrozi A, Soejoedono RD, Semmler T, Bauerfeind R. Molecular Features and Antimicrobial Susceptibilities of Streptococcus equi ssp. equi Isolates from Strangles Cases in Indonesia. Vet Sci 2023; 10:vetsci10010049. [PMID: 36669050 PMCID: PMC9867300 DOI: 10.3390/vetsci10010049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 12/30/2022] [Accepted: 01/03/2023] [Indexed: 01/12/2023] Open
Abstract
Strangles, caused by Streptococcus equi ssp. equi (S. equi equi), is a highly infectious and frequent disease of equines worldwide. No data are available regarding the molecular epidemiology of strangles in Indonesia. This study aimed to characterize S. equi equi isolates obtained from suspected strangles cases in Indonesia in 2018. Isolates originated from seven diseased horses on four different farms located in three provinces of Indonesia. Whole genome sequences of these isolates were determined and used for seM typing, multilocus sequence typing (MLST), and core genome MLS typing (cgMLST). Genomes were also screened for known antimicrobial resistance genes and genes encoding for the recombinant antigens used in the commercial Strangvac® subunit vaccine. All seven S. equi equi isolates from Indonesia belonged to ST179 and carried seM allele 166. Isolates differed from each other by only 2 to 14 cgSNPs and built an exclusive sub-cluster within the Bayesian Analysis of Population Structure (BAPS) cluster 2 (BAPS-2) of the S. equi equi cgMLST scheme. All isolates revealed predicted amino acid sequence identity to seven and high similarity to one of the eight antigen fragments contained in Strangvac®. Furthermore, all isolates were susceptible to beta-lactam antibiotics penicillin G, ampicillin, and ceftiofur. Our data suggest that the horses from this study were affected by strains of the same novel sublineage within globally distributed BAPS-2 of S. equi equi. Nevertheless, penicillin G can be used as a first-choice antibiotic against these strains and Strangvac® may also be protective against Indonesian strains.
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Affiliation(s)
- Dordia Anindita Rotinsulu
- Institute for Hygiene and Infectious Diseases of Animals, Justus Liebig University Giessen, 35392 Giessen, Germany
- School of Veterinary Medicine and Biomedical Sciences, IPB University, Bogor 16680, Indonesia
- Correspondence: or
| | - Christa Ewers
- Institute for Hygiene and Infectious Diseases of Animals, Justus Liebig University Giessen, 35392 Giessen, Germany
| | - Katharina Kerner
- Institute for Hygiene and Infectious Diseases of Animals, Justus Liebig University Giessen, 35392 Giessen, Germany
| | - Amrozi Amrozi
- School of Veterinary Medicine and Biomedical Sciences, IPB University, Bogor 16680, Indonesia
| | | | - Torsten Semmler
- NG-1 Microbial Genomics, Robert Koch Institute, 13353 Berlin, Germany
| | - Rolf Bauerfeind
- Institute for Hygiene and Infectious Diseases of Animals, Justus Liebig University Giessen, 35392 Giessen, Germany
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7
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Frosth S, Morris ERA, Wilson H, Frykberg L, Jacobsson K, Parkhill J, Flock JI, Wood T, Guss B, Aanensen DM, Boyle AG, Riihimäki M, Cohen ND, Waller AS. Conservation of vaccine antigen sequences encoded by sequenced strains of Streptococcus equi subsp. equi. Equine Vet J 2023; 55:92-101. [PMID: 35000217 PMCID: PMC10078666 DOI: 10.1111/evj.13552] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 12/08/2021] [Accepted: 12/30/2021] [Indexed: 12/16/2022]
Abstract
BACKGROUND Streptococcus equi subspecies equi (S equi) is the cause of Strangles, one of the most prevalent diseases of horses worldwide. Variation within the immunodominant SeM protein has been documented, but a new eight-component fusion protein vaccine, Strangvac, does not contain live S equi or SeM and conservation of the antigens it contains have not been reported. OBJECTIVE To define the diversity of the eight Strangvac antigens across a diverse S equi population. STUDY DESIGN Genomic description. METHODS Antigen sequences from the genomes of 759 S equi isolates from 19 countries, recovered between 1955 and 2018, were analysed. Predicted amino acid sequences in the antigen fragments of SEQ0256(Eq5), SEQ0402(Eq8), SEQ0721(EAG), SEQ0855(SclF), SEQ0935(CNE), SEQ0999(IdeE), SEQ1817(SclI) and SEQ2101(SclC) in Strangvac and SeM were extracted from the 759 assembled genomes and compared. RESULTS The predicted amino acid sequences of SclC, SclI and IdeE were identical across all 759 genomes. CNE was truncated in the genome of five (0.7%) isolates. SclF was absent from one genome and another encoded a single amino acid substitution. EAG was truncated in two genomes. Eq5 was truncated in four genomes and 123 genomes encoded a single amino acid substitution. Eq8 was truncated in three genomes, one genome encoded four amino acid substitutions and 398 genomes encoded a single amino acid substitution at the final amino acid of the Eq8 antigen fragment. Therefore, at least 1579 (99.9%) of 1580 amino acids in Strangvac were identical in 743 (97.9%) genomes, and all genomes encoded identical amino acid sequences for at least six of the eight Strangvac antigens. MAIN LIMITATIONS Three hundred and seven (40.4%) isolates in this study were recovered from horses in the UK. CONCLUSIONS The predicted amino acid sequences of antigens in Strangvac were highly conserved across this collection of S equi.
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Affiliation(s)
- Sara Frosth
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Ellen Ruth A Morris
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, Texas, USA
| | | | - Lars Frykberg
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Karin Jacobsson
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | | | - Jan-Ingmar Flock
- Department of Microbiology, Tumour and Cell Biology, Karolinska Institutet, Stockholm, Sweden.,Intervacc AB, Stockholm, Sweden
| | | | - Bengt Guss
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - David M Aanensen
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Ashley G Boyle
- Department of Clinical Studies New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Miia Riihimäki
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Noah D Cohen
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, Texas, USA
| | - Andrew S Waller
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden.,Intervacc AB, Stockholm, Sweden
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8
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Jaramillo C, Gomez DE, Renaud D, Arroyo LG. culture prevalence, associated risk factors and antimicrobial susceptibility in a horse population from Colombia. J Equine Vet Sci 2022; 111:103890. [DOI: 10.1016/j.jevs.2022.103890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 01/25/2022] [Accepted: 01/28/2022] [Indexed: 11/25/2022]
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9
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McGlennon A, Waller A, Verheyen K, Slater J, Grewar J, Aanensen D, Newton R. Surveillance of strangles in UK horses between 2015 and 2019 based on laboratory detection of Streptococcus equi. Vet Rec 2021; 189:e948. [PMID: 34570896 DOI: 10.1002/vetr.948] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 07/21/2021] [Accepted: 09/09/2021] [Indexed: 11/08/2022]
Abstract
BACKGROUND Previously national surveillance data for monitoring strangles (Streptococcus equi infection) in UK horses was limited. Improved awareness and knowledge of positive diagnoses would permit the optimisation of biosecurity protocols, decreasing the prevalence of strangles. METHODS Seven UK laboratories reported positive strangles diagnoses between 1 January 2015 and 31 December 2019 based on identifying Streptococcus equi via agent detection assays from field-based practitioner-submitted samples. Associated clinical history and animal signalment were collected where provided, and descriptive analysis undertaken. RESULTS Within the study period, 1617 laboratory-confirmed diagnoses occurred from samples submitted by 315 veterinary practices. Of these, 51.6% were swabs and 44.0% guttural pouch lavages. Diagnoses were primarily based on qPCR alone (59.6%), qPCR and culture (35.8%), or culture alone (4.6%). A total of 1791 clinical signs were reported for 713 diagnoses, where nasal discharge (31.3%) and pyrexia (20.5%) were most frequently reported. Regions with the highest number of diagnoses included North Yorkshire (n = 75, 4.6%), Staffordshire (n = 71, 4.4%) and West Sussex (North East) (n = 63, 3.9%). CONCLUSION This study presents important insights into the diagnosis and clinical features of strangles in UK horses, even though limited and/or missing clinical history and signalment on laboratory submission forms restricts the completeness of the data.
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Affiliation(s)
- Abigail McGlennon
- Department of Pathobiology and Population Sciences, Royal Veterinary College, Hatfield, UK.,Centre for Preventive Medicine, Animal Health Trust, Newmarket, UK
| | - Andrew Waller
- Centre for Preventive Medicine, Animal Health Trust, Newmarket, UK.,Intervacc, Hägersten, Stockholm, Sweden
| | - Kristien Verheyen
- Department of Pathobiology and Population Sciences, Royal Veterinary College, Hatfield, UK
| | - Josh Slater
- University of Melbourne Veterinary School, Werribee, Victoria, Australia
| | | | - David Aanensen
- Wellcome Trust Sanger Institute, Hinxton, Saffron Walden, England
| | - Richard Newton
- Centre for Preventive Medicine, Animal Health Trust, Newmarket, UK.,British Horseracing Authority, London, UK
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10
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Chen X, Zhao Y, Su L, Wang L, Ma X, Zhang B, Su Y. Enhanced immune effects and protection conferred by simultaneously targeting GAPDH, SeM, and EAG of S. equi via TLR4. Res Vet Sci 2021; 138:100-108. [PMID: 34126448 DOI: 10.1016/j.rvsc.2021.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 04/26/2021] [Accepted: 06/01/2021] [Indexed: 10/21/2022]
Abstract
Strangles, which is caused by Streptococcus equi subspecies equi, is one of the most prevalent equine infectious diseases and poses heavy economic losses worldwide. Although various vaccines have been used for decades, they seemed to be sub-optimal to demonstrate effective protection, and the antigen component of vaccines against S. equi remains to be optimized. In the present study, three target antigens (M-like protein, α2-macroglobulin and IgG-binding protein, and glyceraldehyde-3-phosphate dehydrogenase) were selected and expressed. Mice were immunized and challenged, and their immune response and efficacy were evaluated. The results revealed that this optimized multi-antigen treatment elicited a high expression level of T-cell receptor, major histocompatibility complex I, toll-like receptor TLR-4, and increased specific antibody. In addition, the challenge experiment showed an evidently improved protection efficacy. The present work demonstrated that these three proteins might be used as a promising multicomponent subunit vaccine candidate against S. equi infection.
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Affiliation(s)
- Xiaomeng Chen
- Department of Microbiology and Immunology, College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, Xinjiang, China
| | - Yanan Zhao
- Department of Microbiology and Immunology, College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, Xinjiang, China
| | - Lingling Su
- Xinjiang Academy of Animal Science,Urumqi, Xinjiang, China
| | - Li Wang
- Department of Microbiology and Immunology, College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, Xinjiang, China
| | - Xiaohui Ma
- Department of Microbiology and Immunology, College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, Xinjiang, China
| | - Baojiang Zhang
- Department of Microbiology and Immunology, College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, Xinjiang, China
| | - Yan Su
- Department of Microbiology and Immunology, College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, Xinjiang, China.
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11
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Mitchell C, Steward KF, Charbonneau ARL, Walsh S, Wilson H, Timoney JF, Wernery U, Joseph M, Craig D, van Maanen K, Hoogkamer-van Gennep A, Leon A, Witkowski L, Rzewuska M, Stefańska I, Żychska M, van Loon G, Cursons R, Patty O, Acke E, Gilkerson JR, El-Hage C, Allen J, Bannai H, Kinoshita Y, Niwa H, Becú T, Pringle J, Guss B, Böse R, Abbott Y, Katz L, Leggett B, Buckley TC, Blum SE, Cruz López F, Fernández Ros A, Marotti Campi MC, Preziuso S, Robinson C, Newton JR, Schofield E, Brooke B, Boursnell M, de Brauwere N, Kirton R, Barton CK, Abudahab K, Taylor B, Yeats CA, Goater R, Aanensen DM, Harris SR, Parkhill J, Holden MTG, Waller AS. Globetrotting strangles: the unbridled national and international transmission of Streptococcus equi between horses. Microb Genom 2021; 7:mgen000528. [PMID: 33684029 PMCID: PMC8190609 DOI: 10.1099/mgen.0.000528] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 01/13/2021] [Indexed: 02/02/2023] Open
Abstract
The equine disease strangles, which is characterized by the formation of abscesses in the lymph nodes of the head and neck, is one of the most frequently diagnosed infectious diseases of horses around the world. The causal agent, Streptococcus equi subspecies equi, establishes a persistent infection in approximately 10 % of animals that recover from the acute disease. Such 'carrier' animals appear healthy and are rarely identified during routine veterinary examinations pre-purchase or transit, but can transmit S. equi to naïve animals initiating new episodes of disease. Here, we report the analysis and visualization of phylogenomic and epidemiological data for 670 isolates of S. equi recovered from 19 different countries using a new core-genome multilocus sequence typing (cgMLST) web bioresource. Genetic relationships among all 670 S. equi isolates were determined at high resolution, revealing national and international transmission events that drive this endemic disease in horse populations throughout the world. Our data argue for the recognition of the international importance of strangles by the Office International des Épizooties to highlight the health, welfare and economic cost of this disease. The Pathogenwatch cgMLST web bioresource described herein is available for tailored genomic analysis of populations of S. equi and its close relative S. equi subspecies zooepidemicus that are recovered from horses and other animals, including humans, throughout the world. This article contains data hosted by Microreact.
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Affiliation(s)
| | - Karen F. Steward
- Animal Health Trust, Newmarket, UK
- Present address: Technology Networks, Sudbury, UK
| | | | - Saoirse Walsh
- Animal Health Trust, Newmarket, UK
- Present address: University of Berlin, Berlin, Germany
| | - Hayley Wilson
- Animal Health Trust, Newmarket, UK
- Present address: University of Cambridge, Cambridge, UK
| | | | - Ulli Wernery
- Central Veterinary Research Laboratory, Dubai, UAE
| | | | | | | | | | | | - Lucjan Witkowski
- Institute of Veterinary Medicine, Warsaw University of Life Sciences – SGGW, Warsaw, Poland
| | - Magdalena Rzewuska
- Institute of Veterinary Medicine, Warsaw University of Life Sciences – SGGW, Warsaw, Poland
| | - Ilona Stefańska
- Institute of Veterinary Medicine, Warsaw University of Life Sciences – SGGW, Warsaw, Poland
| | - Monika Żychska
- Institute of Veterinary Medicine, Warsaw University of Life Sciences – SGGW, Warsaw, Poland
| | | | - Ray Cursons
- University of Waikato, Hamilton, New Zealand
| | | | - Els Acke
- Massey University, Palmerston North, New Zealand
| | | | | | | | | | | | | | | | - John Pringle
- Department of Biomedical Science and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Bengt Guss
- Department of Biomedical Science and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | | | | | - Lisa Katz
- University College Dublin, Dublin, Ireland
| | | | | | | | | | | | | | | | | | | | - Ellen Schofield
- Animal Health Trust, Newmarket, UK
- Present address: University of Cambridge, Cambridge, UK
| | | | | | | | - Roxane Kirton
- Redwings Horse Sanctuary, Norwich, UK
- Present address: Royal Society for the Prevention of Cruelty to Animals, Horsham, UK
| | | | - Khalil Abudahab
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Centre for Genomic Pathogen Surveillance, Wellcome Trust Sanger Institute, Cambridge, UK
| | - Ben Taylor
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Centre for Genomic Pathogen Surveillance, Wellcome Trust Sanger Institute, Cambridge, UK
| | - Corin A. Yeats
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Centre for Genomic Pathogen Surveillance, Wellcome Trust Sanger Institute, Cambridge, UK
| | - Richard Goater
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Centre for Genomic Pathogen Surveillance, Wellcome Trust Sanger Institute, Cambridge, UK
| | - David M. Aanensen
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Centre for Genomic Pathogen Surveillance, Wellcome Trust Sanger Institute, Cambridge, UK
| | - Simon R. Harris
- Centre for Genomic Pathogen Surveillance, Wellcome Trust Sanger Institute, Cambridge, UK
- Present address: Microbiotica Limited, Cambridge, UK
| | | | - Matthew T. G. Holden
- Centre for Genomic Pathogen Surveillance, Wellcome Trust Sanger Institute, Cambridge, UK
- University of St Andrews, St Andrews, UK
| | - Andrew S. Waller
- Animal Health Trust, Newmarket, UK
- Department of Biomedical Science and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden
- Intervacc AB, Stockholm, Sweden
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12
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Boyle AG, Mitchell C, Stefanovski D, Waller AS. Horses vaccinated with live attenuated intranasal strangles vaccine seroconvert to SEQ2190 and SeM. Equine Vet J 2021; 54:299-305. [PMID: 33630353 DOI: 10.1111/evj.13443] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 02/07/2021] [Accepted: 02/11/2021] [Indexed: 01/16/2023]
Abstract
BACKGROUND The dual antigen iELISA uses two Streptococcus equi subsp equi surface protein antigens composed of N-terminal portions of SEQ2190 (Antigen A) and SeM (Antigen C). It is currently used to identify animals exposed to S. equi which have developed an immune response to the target antigens. OBJECTIVES To determine the usefulness of the dual antigen iELISA in a population of horses vaccinated with Pinnacle IN. We hypothesised that horses vaccinated for strangles with a live attenuated, non-encapsulated SeM-2 strain of S. equi, would seroconvert when tested 5 weeks later by the dual antigen iELISA. STUDY DESIGN Prospective case-control study. METHODS Three separate serum samples were obtained from 26 client-owned horses vaccinated annually with Pinnacle® IN and 26 university-owned (non-vaccinates): at annual strangles vaccination (S1), 5-week post-vaccination (S2) from vaccinates, and a third (S3) (at 10 weeks) from vaccinates who received a booster. Seropositivity was defined as an OD450 nm value ≥0.5 for one or both antigens. Mixed-effects ordered logistic regression analysis was used to identify factors associated with a suspect seropositive and seropositive value on the combined Antigen A and Antigen C iELISA. Post hoc pairwise comparisons of linear predictive margins were used to assess the differences in OD450 at a specific time between Antigens A and C. RESULTS Nineteen of 25 (76%) vaccinates were seropositive at S2 compared to 1 of 26 (4%) non-vaccinates. When adjusted for sample number, vaccinates were more likely to be seropositive or suspect than non-vaccinates (OR 14; P = .02, 95% CI 1.62-122.03). The OD450 value was significantly larger for Antigen C than Antigen A for vaccinates (P < .001; 95% CI 0.13-0.26) when normalised by age, sex and breed. MAIN LIMITATIONS Guttural pouch sampling for S. equi in seroconverted horses was unavailable. CONCLUSIONS With a high rate of seroconversion to both antigens, the use of the dual antigen iELISA is not recommended in populations vaccinated with Pinnacle® IN.
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Affiliation(s)
- Ashley G Boyle
- Department of Clinical Studies New Bolton Center, University of Pennsylvania, Kennett Square, PA, USA
| | - Catriona Mitchell
- Department of Microbiology, Animal Health Trust, Kentford, Newmarket, Suffolk, UK
| | - Darko Stefanovski
- Department of Clinical Studies New Bolton Center, University of Pennsylvania, Kennett Square, PA, USA
| | - Andrew S Waller
- Department of Microbiology, Animal Health Trust, Kentford, Newmarket, Suffolk, UK.,Intervacc AB, Hägersten, Sweden
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13
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Zhang H, Zhou T, Su L, Wang H, Zhang B, Su Y. Effects of srtA variation on phagocytosis resistance and immune response of Streptococcus equi. INFECTION GENETICS AND EVOLUTION 2021; 89:104732. [PMID: 33503504 DOI: 10.1016/j.meegid.2021.104732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 12/17/2020] [Accepted: 01/21/2021] [Indexed: 11/26/2022]
Abstract
Strangles, which is caused by Streptococcus equi subspecies equi (S. equi), is one of the most prevalent equine infectious diseases with worldwide distribution and leads to serious economic loss in the horse industry. Sortase A (srtA) is a transpeptidase that anchors multiple virulence-associated surface proteins to the cell surface of S. equi. srtA plays a major role in S. equi infection and colonization of the host cell. In this study, we aimed to investigate the effects of srtA mutation on the phagocytic activity and immunogenicity of S. equi. The point-mutated recombinant sortases, including srtA-HT1112 (I88V), srtA-5012 (R147G), and srtA-ZZM17 (control), were expressed, purified, and used to immunize the mouse models. Phagocytic activity was assessed using equine polymorphonuclear cells, whereas opsonophagocytic function and adherence inhibition were measured using the antiserum of these mutants. Mouse serum antibody, bacterial load, and weight gain were also measured. The srtA-HT1112 (I88V) mutant showed significantly enhanced antiphagocytic capability, and its antiserum exhibited increased adherence inhibition activity. In addition, the srtA-HT1112 (I88V) mutant presented the highest lung bacterial load and lowest protection rate (50%) after the challenge with S. equi ZZM17. The srtA-5012 (R147G) mutant exhibited a high IgG2a level and protection rate (62.5%-75%) and the lowest lung bacterial load. These results indicate that the I88V mutation is associated with a high antiphagocytic activity, whereas R147G mutation is associated with the decreased lung bacterial load. Our findings may be useful for the evaluation and development of vaccines.
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Affiliation(s)
- Huan Zhang
- Department of Microbiology and Immunology, College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, Xinjiang, China
| | - Tingting Zhou
- Department of Microbiology and Immunology, College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, Xinjiang, China
| | - Lining Su
- Xinjiang Academy of Animal Science, Urumqi, Xinjiang, China
| | - Hao Wang
- Department of Microbiology and Immunology, College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, Xinjiang, China
| | - Baojiang Zhang
- Department of Microbiology and Immunology, College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, Xinjiang, China
| | - Yan Su
- Department of Microbiology and Immunology, College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, Xinjiang, China.
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14
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Pusterla N, Barnum SM, Byrne BA. Investigation of a 24-Hour Culture Step to Determine the Viability of Streptococcus equi Subspecies equi Via Quantitative Polymerase Chain Reaction in Nasal Secretions From Horses With Suspected Strangles. J Equine Vet Sci 2020; 97:103328. [PMID: 33478766 DOI: 10.1016/j.jevs.2020.103328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/16/2020] [Accepted: 11/16/2020] [Indexed: 10/22/2022]
Abstract
Polymerase chain reaction (PCR)-based detection assays for Streptococcus equi subspecies equi often overestimate the prevalence of samples containing viable organisms. The objective of this study was to determine if viability could be determined using genome quantitation and detection of messenger RNA (mRNA) transcripts for the SeM gene of S. equi in pre- and post-cultured samples. Nasal secretions collected from 42 horses with suspected strangles were tested by culture and by quantitative PCR (qPCR) before and 24 hours after a culture step. Viable S. equi was determined based on the detection of S. equi via culture, the detection of mRNA transcripts for the SeM gene of S. equi by qPCR, and/or an increase in absolute number of SeM target genes of S. equi between pre- and post-cultured samples. Viability was determined in 28/42 samples based on isolation of S. equi (11 samples), the presence of mRNA transcripts for the SeM gene of S. equi (25), and/or an increase in absolute quantitation of the SeM gene of S. equi between pre- and post-culture (17). The overall agreement between culture alone and the three criteria to determine viability was 59%. The overall agreement for the detection of mRNA transcripts and increase in absolute target genes was 88% and 74%, respectively. The combination of mRNA transcripts and increase in absolute target genes was able to determine the viability status in all 42 samples. In the absence of a culture-positive result for S. equi, the determination of viability can be achieved by using molecular strategies applied to samples undergoing a 24-hour culture step.
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Affiliation(s)
- Nicola Pusterla
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA.
| | - Samantha M Barnum
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA
| | - Barbara A Byrne
- Department of Veterinary Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, CA
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15
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Laing G, Christley R, Stringer A, Ashine T, Cian F, Aklilu N, Newton R, Radford A, Pinchbeck G. Pathology, infectious agents and horse- and management-level risk factors associated with signs of respiratory disease in Ethiopian working horses. Equine Vet J 2020; 53:670-681. [PMID: 32853420 DOI: 10.1111/evj.13339] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 07/17/2020] [Accepted: 08/13/2020] [Indexed: 12/19/2022]
Abstract
BACKGROUND Respiratory disease is a common cause for presentation of working horses to clinics in Ethiopia and a priority concern for owners. OBJECTIVES To identify risk factors for and association of pathogens with respiratory signs in working horses. STUDY DESIGN Unmatched case-control study. METHODS Cases were those animals recently coughing (last 7 days) or observed with coughing, nasal discharge or altered respiration at the time of examination. A physical exam and respiratory endoscopy were performed including a tracheal wash sample to detect the presence of pathogens and serology performed on blood. An owner questionnaire was administered. Risk factors were determined using multivariable logistic regression. RESULTS Data on 108 cases and 93 unmatched control horses were obtained. Case horses often had underlying lower airway pathology and were significantly more likely to have Streptococcus zooepidemicus detected (OR: 12.4, 95% CI: 3.6-42.4). There was no evidence of a major role for viral respiratory pathogens. Risk factors included completion of strenuous work (OR: 2.7, 95% CI: 1.2-6.3), drinking from stagnant water sources (OR: 2.3, 95% CI: 1.0-5.2) or being housed on a cobbled floor (OR: 2.0, 95% CI: 1.1-3.8). There were increased odds of respiratory disease in young and old horses in this population. MAIN LIMITATIONS Samples for pathogen detection and cytology were only taken from the trachea. CONCLUSION S. zooepidemicus, a common commensal, may play a role in clinical respiratory disease in this population.
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Affiliation(s)
- Gabrielle Laing
- Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - Robert Christley
- Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - Andrew Stringer
- Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, USA
| | - Tibebu Ashine
- SPANA (Society for the Protection of Animals Abroad), Debre Zeit, Ethiopia
| | | | - Nigatu Aklilu
- SPANA (Society for the Protection of Animals Abroad), Debre Zeit, Ethiopia
| | | | - Alan Radford
- Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - Gina Pinchbeck
- Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
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16
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SpeS: A Novel Superantigen and Its Potential as a Vaccine Adjuvant against Strangles. Int J Mol Sci 2020; 21:ijms21124467. [PMID: 32586031 PMCID: PMC7352279 DOI: 10.3390/ijms21124467] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 06/19/2020] [Accepted: 06/19/2020] [Indexed: 11/16/2022] Open
Abstract
Bacterial superantigens (sAgs) are powerful activators of the immune response that trigger unspecific T cell responses accompanied by the release of proinflammatory cytokines. Streptococcus equi (S. equi) and Streptococcus zooepidemicus (S. zooepidemicus) produce sAgs that play an important role in their ability to cause disease. Strangles, caused by S. equi, is one of the most common infectious diseases of horses worldwide. Here, we report the identification of a new sAg of S. zooepidemicus, SpeS, and show that mutation of the putative T cell receptor (TCR)-binding motif (YAY to IAY) abrogated TCR-binding, whilst maintaining interaction with major histocompatibility complex (MHC) class II molecules. The fusion of SpeS and SpeSY39I to six S. equi surface proteins using two different peptide linkers was conducted to determine if MHC class II-binding properties were maintained. Proliferation assays, qPCR and flow cytometry analysis showed that SpeSY39I and its fusion proteins induced less mitogenic activity and interferon gamma expression when compared to SpeS, whilst retaining Antigen-Presenting Cell (APC)-binding properties. Our data suggest that SpeSY39I-surface protein fusions could be used to direct vaccine antigens towards antigen-presenting cells in vivo with the potential to enhance antigen presentation and improve immune responses.
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17
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Abstract
Abigail McGlennon from the Animal Health Trust introduces a new project to gather information on cases of strangles in horses throughout the UK.
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18
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Robinson C, Waller AS, Frykberg L, Flock M, Zachrisson O, Guss B, Flock JI. Intramuscular vaccination with Strangvac is safe and induces protection against equine strangles caused by Streptococcus equi. Vaccine 2020; 38:4861-4868. [PMID: 32507408 DOI: 10.1016/j.vaccine.2020.05.046] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 05/13/2020] [Accepted: 05/15/2020] [Indexed: 12/11/2022]
Abstract
The equine disease strangles, caused by Streptococcus equi, remains a major cause of welfare and economic cost to the global horse industry. Here we report the safety, immunogenicity and efficacy of a novel multi-component chimeric fusion protein vaccine, called Strangvac, when administered to ponies via the intramuscular route. Across the four studies, Strangvac was safe and induced robust antibody responses towards the vaccine components in blood serum and the nasopharynx, which were boosted by revaccination up to 12 months after a primary course of 2 vaccinations 4 weeks apart. The vaccine response did not cross-react with a commercial strangles iELISA, which identifies horses that have been exposed to S. equi, demonstrating that it was possible to differentiate infected from vaccinated animals (DIVA). Following challenge with S. equi strain 4047 (Se4047), all 36 control ponies that had received an adjuvant-only placebo vaccine developed clinical signs of strangles. In contrast, intramuscular vaccination with Strangvac protected ponies significantly from challenge with Se4047 at two weeks (5 of 16 ponies protected (31%), P = 0.04) and two months (7 of 12 ponies protected (58%), P = 0.0046 (including pooled control data) after second vaccination. Optimal protection (15 of 16 ponies protected (94%), P < 0.0001) was observed following challenge at two weeks post-third vaccination. Our data demonstrate that Strangvac is safe, has DIVA capability and provides a rapid onset of protective immunity against strangles. We conclude that Strangvac is a valuable tool with which to protect horses from strangles, particularly during high-risk periods, whilst maintaining the mobility of horse populations as required by the global equine industry.
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Affiliation(s)
- Carl Robinson
- Department of Bacteriology, Animal Health Trust, Lanwades Park, Kentford, Newmarket, CB8 7UU, United Kingdom
| | - Andrew S Waller
- Department of Bacteriology, Animal Health Trust, Lanwades Park, Kentford, Newmarket, CB8 7UU, United Kingdom
| | - Lars Frykberg
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, P.O. Box 7036, SE-750 07 Uppsala, Sweden
| | - Margareta Flock
- Department of Microbiology, Tumour and Cellbiology, Karolinska Institutet, P.O. Box 280, SE-171 77 Stockholm, Sweden
| | | | - Bengt Guss
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, P.O. Box 7036, SE-750 07 Uppsala, Sweden
| | - Jan-Ingmar Flock
- Department of Microbiology, Tumour and Cellbiology, Karolinska Institutet, P.O. Box 280, SE-171 77 Stockholm, Sweden; Intervacc AB, P.O. Box 112, SE-129 22 Hӓgersten, Sweden.
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19
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Noll LW, Stoy CPA, Wang Y, Porter EG, Lu N, Liu X, Burklund A, Peddireddi L, Hanzlicek G, Henningson J, Chengappa MM, Bai J. Development of a nested PCR assay for detection of Streptococcus equi subspecies equi in clinical equine specimens and comparison with a qPCR assay. J Microbiol Methods 2020; 172:105887. [PMID: 32165161 DOI: 10.1016/j.mimet.2020.105887] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 03/08/2020] [Accepted: 03/08/2020] [Indexed: 10/24/2022]
Abstract
Streptococcus equi subsp. equi is a Gram positive bacterial pathogen commonly associated with strangles in horses, a respiratory disease characterized by abscessation of submandibular and retropharyngeal lymph nodes which can lead to obstruction of the airway. Several real-time PCR (qPCR) assays have been developed for detection of S. equi from horses with many targeting conserved regions of the S. equi cell wall-associated M-protein (SeM), a major virulence factor and immunogen of S. equi. Our objective was to develop a nested PCR (nPCR) targeting SeM and an 18S rRNA internal control gene for detection of S. equi from horses with potential improvement in detection sensitivity compared to a qPCR. Primers and probes from the Kansas State Veterinary Diagnostic Laboratory (KSVDL) S. equi clinical testing assay were utilized for all qPCR testing. Primers flanking the SeM qPCR target region were selected for an initial end-point PCR step of the nested assay; PCR product from the end-point reaction then served as template for the qPCR reaction step of the nested assay. Sample nucleic acid was also tested directly with qPCR to allow for assay comparison. Nucleic acid from clinical specimens (n = 188) submitted to KSVDL were tested in parallel with each assay. The nPCR and qPCR assays identified 22.9% (43/188) and 13.3% (25/188) of samples positive for S. equi, respectively. None of the samples positive by qPCR were negative by nPCR. The PCR products from all positive samples were submitted for DNA sequencing. Each of the 25 samples positive by both assays had a high nucleotide identity match (>96%) to the SeM gene. Among the samples positive by nPCR but negative by qPCR, 17 of 18 were sequence confirmed for SeM at greater than 96% nucleotide identity. Based on the nPCR Ct (37.8) of the one sequence un-confirmed case, it is likely that the S. equi bacterial load in this sample was below the necessary concentration for successful sequencing. Limit of detection (LOD) for the nPCR was established at a Ct of 37, and based both on the LOD of the qPCR assay (Ct of 37), as determined by standard curve data, and on the highest nPCR Cts (~37) of clinical samples able to result in SeM sequence-confirmation. As demonstrated by sequencing confirmation, the nPCR assay targeting the SeM gene is highly specific to S. equi. The increased sensitivity of the nPCR, compared to the qPCR, may reduce the number of false negative sample results in clinical testing and provide a superior detection method during low bacterial shedding periods.
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Affiliation(s)
- Lance W Noll
- Kansas State Veterinary Diagnostic Laboratory, Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas 66506, USA.
| | - Colin P A Stoy
- Kansas State Veterinary Diagnostic Laboratory, Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas 66506, USA
| | - Yin Wang
- Kansas State Veterinary Diagnostic Laboratory, Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas 66506, USA
| | - Elizabeth G Porter
- Kansas State Veterinary Diagnostic Laboratory, Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas 66506, USA
| | - Nanyan Lu
- Kansas State Veterinary Diagnostic Laboratory, Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas 66506, USA; Bioinformatics Center, Kansas State University, Manhattan, Kansas 66506, USA
| | - Xuming Liu
- Kansas State Veterinary Diagnostic Laboratory, Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas 66506, USA
| | - Amy Burklund
- Kansas State Veterinary Diagnostic Laboratory, Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas 66506, USA
| | - Lalitha Peddireddi
- Kansas State Veterinary Diagnostic Laboratory, Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas 66506, USA
| | - Gregg Hanzlicek
- Kansas State Veterinary Diagnostic Laboratory, Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas 66506, USA
| | - Jamie Henningson
- Kansas State Veterinary Diagnostic Laboratory, Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas 66506, USA
| | - M M Chengappa
- Kansas State Veterinary Diagnostic Laboratory, Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas 66506, USA
| | - Jianfa Bai
- Kansas State Veterinary Diagnostic Laboratory, Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas 66506, USA.
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20
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El-Hage CM, Bannai H, Wiethoelter AK, Firestone SM, Heislers CM, Allen JL, Waller AS, Gilkerson JR. Serological responses of Australian horses using a commercial duplex indirect ELISA following vaccination against strangles. Aust Vet J 2019; 97:220-224. [PMID: 31236928 DOI: 10.1111/avj.12825] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 01/22/2019] [Accepted: 02/18/2019] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To determine the nature of serological responses in Australian horses using a commercial duplex indirect ELISA (iELISA) following vaccination against strangles. DESIGN A group (n = 19) of client-owned horses from five properties were recruited to receive a primary course of a Streptococcus equi subsp. equi (S. equi) extract vaccine. Serological responses were determined by duplex iELISA incorporating S. equi-specific fragments of two cell wall proteins, SEQ2190 and SeM (antigens (Ag) A and C, respectively). METHODS The horses were administered a primary strangles vaccination course. Blood was collected immediately prior to each of the three vaccinations at 2-week intervals and additionally at 28 and 56 days following the 3rd vaccination (V3). RESULTS Significant increases in mean antibody levels of horses following vaccination were limited only to AgC, which was significantly increased at T2/V3, 14 days following V2 (ratio of geometric means = 3.7; 95% confidence interval (CI): 1.6, 8.4; P = 0.003). There was no increase in mean antibody to Ag A (ratio of geometric means = 1.4; 95% CI: 0.6, 3.2; P = 0.39). Four horses (22%) exceeded the test cut-off for AgC following vaccination. CONCLUSION Vaccination of Australian horses is unlikely to interfere greatly with detection of strangles using the duplex iELISA. No responses would be anticipated to AgA following vaccination with Equivac© S/Equivac© 2in1 and only a minority are likely to respond to AgC. We conclude that the results of this study validate the usefulness of the duplex iELISA to assist control measures for strangles outbreaks in Australian horse populations.
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Affiliation(s)
- C M El-Hage
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - H Bannai
- Equine Research Institute, Japan Racing Association Tochigi, Japan
| | - A K Wiethoelter
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - S M Firestone
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - C M Heislers
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - J L Allen
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - A S Waller
- Animal Health Trust, Kennett, Newmarket, UK
| | - J R Gilkerson
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, 3010, Australia
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21
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MacFadyen AC, Waller AS, Paterson GK. Streptococcus hillyeri sp. nov., isolated from equine trachea. Int J Syst Evol Microbiol 2019; 69:3009-3013. [PMID: 31287393 DOI: 10.1099/ijsem.0.003489] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Strain 28462T, which had Gram-stain-positive, catalase-negative coccus-shaped cells, was isolated from a routine tracheal sample from a 3 year old thoroughbred horse. 16S rRNA gene sequence analysis revealed it to be most closely related to, but distinct from, Streptococcus henryi (95.7 % identity), Streptococcusplurextorum (95.8 %), Streptococcusporci (96.4 %) and Streptococcus caprae (95.1 %). Similarity values derived from sequences from sodA and rpoB genes were consistent with strain 28462T belonging to a species distinct from these four streptococci. At the whole genome level, strain 28462T had an average nucleotide identity value <95 % and an inferred DNA-DNA hybridization value <70 % when compared to S. henryi, Streptococcus. plurextorum and S. porci with no S. caprae genome sequence being available. Finally, various phenotypic characteristics distinguish strain 28462T from each of these species. Based on the genotypic and phenotypic results, it is proposed that strain 28462T is a novel species, with the name Streptococcus hillyeri sp. nov. The type strain is 28462T (=DSM 107591T=CCUG 72762T).
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Affiliation(s)
- A C MacFadyen
- Royal (Dick) School of Veterinary Studies and The Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian, EH25 9RG, UK
| | - A S Waller
- Animal Health Trust, Lanwades Park Kentford, Newmarket, Suffolk, CB8 7UU, UK
| | - G K Paterson
- Royal (Dick) School of Veterinary Studies and The Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian, EH25 9RG, UK
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22
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Cárdenas DM, Duque D. Tratamiento quirúrgico de condroides en las bolsas guturales de un equino mediante abordaje Whitehouse modificado. Reporte de caso. REVISTA DE LA FACULTAD DE MEDICINA VETERINARIA Y DE ZOOTECNIA 2019. [DOI: 10.15446/rfmvz.v66n2.82435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Una yegua de raza caballo criollo colombiano (CCC) de 34 meses de edad fue remitidaal Centro de Veterinaria y Zootecnia de la Universidad CES, en la ciudad de Medellín(Colombia), para la extracción quirúrgica de condroides en ambas bolsas guturales. Lapaciente se intervino en estación utilizando neuroleptoanalgesia y a continuación, seempleó la técnica Whitehouse modificado en cada bolsa gutural para extraer la totalidadde los condroides. Posteriormente, se realizó tratamiento antibiótico y antinflamatoriopre y post quirúrgico con trimetoprim-sulfadiazina y flunixin meglumine vía sistémica;además, penicilina G sódica local. Luego de la intervención la paciente fue dada de altasin complicaciones y finalmente se evidenció la resolución completa de la condiciónrespiratoria. El reporte de este caso permitirá conocer con detalle la técnica Whitehousemodificado, así como sus retos quirúrgicos y consideraciones, ya que a la fecha en Colombiano hay otros reportes al respecto en un CCC.
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Barros T, Moran G, Uberti B. Reactive Seizures After Vaccination in a Thoroughbred Broodmare. J Equine Vet Sci 2019. [DOI: 10.1016/j.jevs.2018.12.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Laing G, Christley R, Stringer A, Aklilu N, Ashine T, Newton R, Radford A, Pinchbeck G. Respiratory disease and sero-epidemiology of respiratory pathogens in the working horses of Ethiopia. Equine Vet J 2018; 50:793-799. [PMID: 29574904 PMCID: PMC6175379 DOI: 10.1111/evj.12834] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 03/02/2018] [Indexed: 12/02/2022]
Abstract
BACKGROUND Pathogens are frequently implicated in equine respiratory disease. In Ethiopia, respiratory disease is a frequent cause for presentation at veterinary clinics and a priority concern for users of working horses. However, there is little existing literature on possible aetiologies. OBJECTIVES Determine prevalence of respiratory signs and exposure to major respiratory pathogens through a serological survey. STUDY DESIGN Cross-sectional. METHODS Systematically selected horses from 19 sites in central Ethiopia were examined clinically and sampled once (August-December 2013). A face-to-face interview collected data on horses' management and history. Serological testing targeted equine influenza virus (EIV), equine herpesviruses-1 (EHV-1) and -4 (EHV-4), equine rhinitis viruses A (ERAV) and B (ERBV), equine arteritis virus (EAV) and Streptococcus equi subspecies equi (S. equi). RESULTS Owners reported a recent history of coughing in 38% of horses and nasal discharge in 7%. No animals were observed coughing during examination but 6% had a nasal discharge. Antibodies towards S. equi, were most prevalent (8%, 33/350). Antibodies to EAV were confirmed in one animal (0.3%). Low antibody titres to EHV-1/4 and ERA/BV suggested prior exposure but antibodies to EIV were not detected. Multivariable, multilevel logistic regression analysis for risk factors associated with S. equi serostatus showed higher odds of seropositivity in younger animals and those working less frequently. MAIN LIMITATIONS A single serological sample cannot describe dynamic changes in antibodies. Sampling horses at the place of work may result in healthy-worker bias. CONCLUSIONS S. equi may be endemic in this population and contributing, in part, to the occurrence of respiratory disease. Low prevalence of antibodies to viruses, with the exception of EIV, indicates these pathogens are present, but unlikely a predominant cause of respiratory signs and noninfectious causes of disease should also be investigated. Working horses in this region would be vulnerable to incursion of equine influenza.
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Affiliation(s)
- G. Laing
- Institute of Infection and Global HealthUniversity of LiverpoolLiverpoolUK
| | - R. Christley
- Institute of Infection and Global HealthUniversity of LiverpoolLiverpoolUK
| | - A. Stringer
- Institute of Infection and Global HealthUniversity of LiverpoolLiverpoolUK
| | - N. Aklilu
- SPANA (Society for the Protection of Animals Abroad)Debre ZeitEthiopia
| | - T. Ashine
- SPANA (Society for the Protection of Animals Abroad)Debre ZeitEthiopia
| | - R. Newton
- Animal Health TrustNewmarketSuffolkUK
| | - A. Radford
- Institute of Infection and Global HealthUniversity of LiverpoolLiverpoolUK
| | - G. Pinchbeck
- Institute of Infection and Global HealthUniversity of LiverpoolLiverpoolUK
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Strangvac: A recombinant fusion protein vaccine that protects against strangles, caused by Streptococcus equi. Vaccine 2018; 36:1484-1490. [DOI: 10.1016/j.vaccine.2018.01.030] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 12/20/2017] [Accepted: 01/10/2018] [Indexed: 01/13/2023]
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Pusterla N, Leutenegger CM, Barnum SM, Byrne BA. Use of quantitative real-time PCR to determine viability of Streptococcus equi subspecies equi in respiratory secretions from horses with strangles. Equine Vet J 2018; 50:697-700. [PMID: 29341315 DOI: 10.1111/evj.12809] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 01/10/2018] [Indexed: 11/29/2022]
Abstract
BACKGROUND In recent years, molecular approaches have been able to characterise the viability of equine upper respiratory tract pathogens using absolute molecular quantitation as well as detection of transcripts for virulence genes. OBJECTIVES The objective of this study was to investigate molecular surrogates for S. equi subspecies equi (S. equi) viability in biological samples from horses with strangles. STUDY DESIGN Retrospective cross-sectional study. METHODS S. equi culture-positive and culture-negative upper airway secretions were assessed by qPCR at the genomic (gDNA) and complimentary DNA (cDNA) level for various target genes (SeM, SEQ2190, eqbE and szpSe). Absolute quantitation was performed using standard curves, and the results were expressed as number of S. equi target genes per μl of gDNA or cDNA. Additionally, the presence or absence of S. equi gene expression for the various target genes was assessed and compared with the culture results. RESULTS While all 21 culture-positive samples tested S. equiqPCR positive, up to 43.7 and 18.9% of 64 culture-negative samples tested qPCR positive at the gDNA and cDNA level, respectively. Significant differences in absolute quantitation for S. equi at the gDNA level were found between culture-positive and culture-negative samples. When absolute quantitation of S. equi target genes at the gDNA level was assessed with the presence or absence of transcripts, there was a significantly higher S. equi target gene number in samples with expression of transcripts compared with samples with no expression of transcripts. MAIN LIMITATIONS The lack of standardisation of samples collected in the field and the delay from sample collection to samples processing may have negatively affected the cultivability of S. equi and mRNA quality. CONCLUSIONS Molecular viability for S. equi can be investigated by determining absolute quantitation and/or by detecting mRNA for specific target genes. However, veterinarians have to be cautioned that any qPCR-positive result for S. equi needs to be taken seriously and trigger biosecurity protocols aimed at reducing spread.
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Affiliation(s)
- N Pusterla
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, California, USA
| | | | - S M Barnum
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, California, USA
| | - B A Byrne
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, California, USA
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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; 32:633-647. [PMID: 29424487 PMCID: PMC5867011 DOI: 10.1111/jvim.15043] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 12/14/2017] [Accepted: 12/14/2017] [Indexed: 11/28/2022] Open
Abstract
This consensus statement update reflects our current published knowledge and opinion about clinical signs, pathogenesis, epidemiology, treatment, complications, and control of strangles. This updated statement emphasizes varying presentations in the context of existing underlying immunity and carrier states of strangles in the transmission of disease. The statement redefines the “gold standard” for detection of possible infection and reviews the new technologies available in polymerase chain reaction diagnosis and serology and their use in outbreak control and prevention. We reiterate the importance of judicious use of antibiotics in horses with strangles. This updated consensus statement reviews current vaccine technology and the importance of linking vaccination with currently advocated disease control and prevention programs to facilitate the eradication of endemic infections while safely maintaining herd immunity. Differentiation between immune responses to primary and repeated exposure of subclinically infected animals and responses induced by vaccination is also addressed.
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Affiliation(s)
- A G Boyle
- University of Pennsylvania, New Bolton Center, Kennett Square, PA
| | - J F Timoney
- University of Kentucky, Gluck Research Center, Lexington, KY
| | | | - M T Hines
- University of Tennessee, Knoxville, TN
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Trimble AC, Delph KM, Beard LA, Davis EG. Staphyloccocus aureus
‐associated infarctive purpura haemorrhagica, immune‐mediated haemolytic anaemia and myocarditis in a Quarter Horse mare. EQUINE VET EDUC 2017. [DOI: 10.1111/eve.12855] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- A. C. Trimble
- Kansas State University Veterinary Health Center Manhattan Kansas USA
| | - K. M. Delph
- Kansas State University Veterinary Health Center Manhattan Kansas USA
| | - L. A. Beard
- Kansas State University Veterinary Health Center Manhattan Kansas USA
| | - E. G. Davis
- Kansas State University Veterinary Health Center Manhattan Kansas USA
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Goyen KA, Wright JD, Cunneen A, Henning J. Playing with fire - What is influencing horse owners' decisions to not vaccinate their horses against deadly Hendra virus infection? PLoS One 2017. [PMID: 28636633 PMCID: PMC5479593 DOI: 10.1371/journal.pone.0180062] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Hendra virus is a zoonotic paramyxovirus, which causes severe respiratory and neurological disease in horses and humans. Since 2012, the Hendra virus sub-unit G vaccine has been available for horse vaccination in Australia. Uptake of the vaccine has been limited and spill-over events of Hendra virus infection in horses continue to occur. We conducted an online, questionnaire-based cross-sectional study of 376 horse owners belonging to a variety of different equestrian clubs in Queensland, Australia, to identify risk factors for non-vaccination against Hendra virus. A total of 43.1% (N = 162) of horse owners indicated that they currently did not vaccinate against Hendra virus infection, while 56.9% (N = 214) currently vaccinated against Hendra virus infection. A total of 52 risk factors were evaluated relating to equestrian activities, horse management, perceived risk and severity of horse and human infection with Hendra virus, side effects of Hendra vaccination, other vaccinations conducted by horse owners and horse owners’ attitudes towards veterinarians. The final multivariable logistics regression model identified the following risk factors associated with increased odds of non-vaccination against Hendra virus: 1) perceived low risk (compared to high) of Hendra virus infection to horses (considering the horse owners’ location and management practices) or horse owners were unsure about the risk of infection, 2) perceived moderate severity (compared to very severe or severe) of Hendra virus infection in humans, 3) horse owners non-vaccination of their pets, 4) horse owners non-vaccination against strangles disease in horses, 5) handling of more than three horses per week (compared to one horse only) and 6) perceived attitude that veterinarians had a high motivation of making money from Hendra virus vaccination (compared to veterinarians having a low motivation of making money from Hendra virus vaccination). Horse owners were more likely to vaccinate against Hendra virus if horses were used for dressage, show jumping or eventing. The study also identified horse owners’ concerns about side-effects and about the lack of evidence on vaccine efficacy.
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Affiliation(s)
- Kailiea Arianna Goyen
- School of Veterinary Science, Faculty of Science, University of Queensland, Gatton, Queensland, Australia
| | - John David Wright
- School of Veterinary Science, Faculty of Science, University of Queensland, Gatton, Queensland, Australia
| | - Alexandra Cunneen
- School of Veterinary Science, Faculty of Science, University of Queensland, Gatton, Queensland, Australia
| | - Joerg Henning
- School of Veterinary Science, Faculty of Science, University of Queensland, Gatton, Queensland, Australia
- * E-mail:
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Boyle AG, Stefanovski D, Rankin SC. Comparison of nasopharyngeal and guttural pouch specimens to determine the optimal sampling site to detect Streptococcus equi subsp equi carriers by DNA amplification. BMC Vet Res 2017; 13:75. [PMID: 28335829 PMCID: PMC5364677 DOI: 10.1186/s12917-017-0989-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 03/04/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Streptococcus equi subsp equi (S. equi) is the cause of "equine strangles" which is a highly infectious upper respiratory disease. Detection of S. equi is influenced by site of specimen collection, method of sampling, and type of diagnostic test that is performed. We hypothesized i) that a loop-mediated isothermal amplification (LAMP) assay that targets the S. equi-specific eqbE gene would be more sensitive than a realtime PCR assay that targets the S. equi-specific seeI gene and ii) that LAMP of specimens obtained by guttural pouch lavage (GPL) would be more sensitive than LAMP of nasopharyngeal specimens to identify S. equi carriers. METHODS A nasopharyngeal flocked swab, nasopharyngeal wash, and GPL specimen was collected from 44 convalescent horses and the eqbE LAMP assay was performed. The seeI realtime PCR assay and aerobic culture were also performed on the GPL specimen. Logistic regression was performed to compare sampling sites and test methods (P-values ≤0.05 were considered significant). RESULTS One of 41 nasopharyngeal flocked swabs, 6/38 nasopharyngeal wash and 24/44 GPL specimens were positive by eqbE LAMP. 18/44 GPL specimens were positive by seeI PCR and S. equi was isolated from 4/44 of these specimens. Detection of S. equi DNA was 51 times more likely from the GPL samples than nasopharyngeal samples (OR 51.0, P < 0.0001). When eqbE LAMP GPL samples were positive, it was eight times more likely that the guttural pouch had any abnormality on endoscopy (OR 8.2, P ≤ 0.005), almost 20 times more likely that mild empyema was found (OR 19.7, P ≤ 0.002), and eight times more likely that the SeeI PCR was positive for S. equi DNA (OR 8.1, P ≤ 0.006). CONCLUSION This study demonstrates that guttural pouch lavage specimens should be used to detect S. equi and that the eqbE LAMP assay was comparable to the seeI PCR.
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Affiliation(s)
- Ashley G Boyle
- Department of Clinical Studies New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, 382 West Street Rd, Kennett Square, PA, 19348, USA.
| | - Darko Stefanovski
- Department of Clinical Studies New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, 382 West Street Rd, Kennett Square, PA, 19348, USA
| | - Shelley C Rankin
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, 3900 Spruce Street, Room 4036, Philadelphia, PA, 19104, USA
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Tirosh-Levy S, Blum SE, Steward KF, Waller AS, Steinman A. Streptococcus equi subspecies equi in horses in Israel: seroprevalence and strain types. Vet Rec Open 2016; 3:e000187. [PMID: 27651915 PMCID: PMC5013422 DOI: 10.1136/vetreco-2016-000187] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 07/20/2016] [Accepted: 07/22/2016] [Indexed: 11/04/2022] Open
Abstract
The purpose of this cross-sectional study was to determine the seroprevalence of Streptococcus equi in Israel, to monitor seropositive horses over time and to identify archived strains that were recovered from Israeli horses. A serological survey of 200 healthy horses on 20 farms throughout Israel was performed to detect recent exposure to S equi antigens A and C via indirect ELISA. Seroprevalence was 9.5 per cent (19/200) and positive horses were found in 30 per cent (6/20) of the farms. Sixteen horses that returned a positive serology result were retested three and six months later. Most (12/16) positive horses remained positive, which suggests the presence of animals with persistent infection. Molecular characterisation of S equi strains by sequencing of the SeM gene of 16 archived isolates of S equi that were recovered from clinical cases of strangles between 2008 and 2012 identified two strains: SeM-2 and SeM-28.
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Affiliation(s)
- S Tirosh-Levy
- Koret School of Veterinary Medicine, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem , Rehovot , Israel
| | - S E Blum
- Department of Bacteriology , Kimron Veterinary Institute , Bet Dagan , Israel
| | - K F Steward
- Centre for Preventive Medicine, Animal Health Trust , Newmarket, Suffolk , UK
| | - A S Waller
- Centre for Preventive Medicine, Animal Health Trust , Newmarket, Suffolk , UK
| | - A Steinman
- Koret School of Veterinary Medicine, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem , Rehovot , Israel
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Abstract
Strangles, characterised by pyrexia followed by abscessation of the lymph nodes of the head and neck, was first described in 1251 (Rufus 1251) and the causative agent, Streptococcus equi, was identified in 1888 (Schutz 1888). However, despite more than a century of research into this disease, strangles remains the most frequently diagnosed infection of horses with over 600 outbreaks being identified in the UK alone each year (Parkinson and others 2011). Here, Andrew Waller reviews some of the recent advances in the understanding of the evolution of S equi and puts this into the context of preventing and resolving outbreaks of infection.
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Affiliation(s)
- Andrew S Waller
- Animal Health Trust, Lanwades Park, Newmarket, Suffolk CB8 7UU
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Boyle AG, Rankin SC, Duffee L, Boston RC, Wheeler-Aceto H. Streptococcus equi Detection Polymerase Chain Reaction Assay for Equine Nasopharyngeal and Guttural Pouch Wash Samples. J Vet Intern Med 2015; 30:276-81. [PMID: 26678318 PMCID: PMC4913660 DOI: 10.1111/jvim.13808] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 08/17/2015] [Accepted: 11/09/2015] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Bacterial culture and polymerase chain reaction (PCR) assays for the detection of Streptococcus equi in nasopharyngeal washes (NPW) and guttural pouch lavage (GPL) samples have low sensitivity. In human diagnostics, processing of samples with flocked swabs has improved recovery rates of bacterial agents because of improved surface area and elution factors. HYPOTHESIS For S. equi subsp. equi (S. equi) detection in NPW and GPL samples we hypothesized that: direct-PCR would be more reliable than flocked swab culture (FS culture); flocked swab PCR (FS-PCR) would be equivalent to direct-PCR; and FS culture would be more reliable than traditional culture. SAMPLES A total of 193 samples (134 NPW and 59 GPL) from 113 horses with either suspected S. equi infection, convalescing from a known S. equi infection, or asymptomatic horses screened for S. equi. METHODS Prospective study. Samples were submitted for S. equi direct-PCR. Using logistic regression, direct-PCR (gold standard) was compared to FS culture, traditional culture, and FS-PCR also performed. RESULTS Direct-PCR was statistically more sensitive than FS-PCR, FS culture, and traditional culture (P < .001). All methods had sensitivities <70% relative to the direct-PCR. FS culture had a similar sensitivity relative to traditional culture. The odds of GPL samples being positive on direct-PCR (P = .030) and FS-PCR were greater than those for NPW samples (P = .021). CONCLUSIONS AND CLINICAL IMPORTANCE Use of flocked swabs during laboratory preprocessing did not improve detection of S. equi via either PCR or bacterial culture from samples. Direct-PCR is the preferred method of detection of S. equi.
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Affiliation(s)
- A G Boyle
- Department of Clinical Studies New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA, 19348
| | - S C Rankin
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA, 19348
| | - L Duffee
- Department of Clinical Studies New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA, 19348
| | - R C Boston
- Department of Clinical Studies New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA, 19348
| | - H Wheeler-Aceto
- Department of Clinical Studies New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA, 19348
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Strangles in horses can be caused by vaccination with Pinnacle I. N. Vaccine 2015; 33:3440-3. [PMID: 26025806 DOI: 10.1016/j.vaccine.2015.05.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 05/05/2015] [Indexed: 11/22/2022]
Abstract
The differentiation of live attenuated vaccine strains from their progenitor and wild-type counterparts is important for ongoing surveillance of product safety and improved guidelines on their use. We utilised a genome sequencing approach to confirm that two cases of strangles in previously healthy horses that had received the Pinnacle I. N. vaccine (Zoetis) were caused by the vaccine strain. Our data shed new light on the safety of this vaccine and suggest that factors beyond the maturity of the animal's immune system influence the development of adverse reactions.
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Robinson C, Heather Z, Slater J, Potts N, Steward KF, Maskell DJ, Fontaine MC, Lee JJ, Smith K, Waller AS. Vaccination with a live multi-gene deletion strain protects horses against virulent challenge with Streptococcus equi. Vaccine 2015; 33:1160-7. [PMID: 25597942 DOI: 10.1016/j.vaccine.2015.01.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 01/05/2015] [Accepted: 01/06/2015] [Indexed: 10/24/2022]
Abstract
Strangles, caused by Streptococcus equi subspecies equi (S. equi) is one of the most frequently diagnosed infectious diseases of horses and there remains a significant need to develop new preventative vaccines. We generated a live vaccine strain of S. equi containing deletions in six genes: sagA, hasA, aroB, pyrC, seM and recA, which was administered to nine Welsh mountain ponies via the intramuscular route. Four vaccinated ponies developed adverse reactions following the first vaccination from which the live vaccine strain was isolated. Two of these ponies were withdrawn from the study and seven ponies received a second vaccination, one of which then developed an adverse reaction. Nine control ponies injected with culture media alone developed no adverse reactions. Following challenge with a virulent strain of S. equi, none of the seven vaccinated ponies had developed clinical signs of strangles eleven days post-challenge, compared to six of nine control ponies over the same period (P=0.0114). A lymph node abscess was identified in one of the seven vaccinated ponies at post-mortem examination, whilst all nine control ponies had at least one lymph node abscess (P=0.0009). Three of the six vaccinated ponies that were protected from strangles had not developed an adverse reaction following vaccination, suggesting that a better understanding of the pro-inflammatory responses to S. equi could lead to the development of a live attenuated vaccine against strangles that is safe for administration via intramuscular injection.
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Affiliation(s)
- Carl Robinson
- Animal Health Trust, Lanwades Park, Kentford, Newmarket CB8 7UU, United Kingdom
| | - Zoe Heather
- Animal Health Trust, Lanwades Park, Kentford, Newmarket CB8 7UU, United Kingdom
| | - Josh Slater
- Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Herts AL9 7TA, United Kingdom
| | - Nicola Potts
- Animal Health Trust, Lanwades Park, Kentford, Newmarket CB8 7UU, United Kingdom
| | - Karen F Steward
- Animal Health Trust, Lanwades Park, Kentford, Newmarket CB8 7UU, United Kingdom
| | - Duncan J Maskell
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 OES, United Kingdom
| | - Michael C Fontaine
- Institute for Cell and Molecular Biosciences, The Medical School, University of Newcastle upon Tyne, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Jeong-Jin Lee
- Institute for Cell and Molecular Biosciences, The Medical School, University of Newcastle upon Tyne, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Ken Smith
- Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Herts AL9 7TA, United Kingdom
| | - Andrew S Waller
- Animal Health Trust, Lanwades Park, Kentford, Newmarket CB8 7UU, United Kingdom.
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