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NAKAJIMA K, KASUYA K, SENBA H, TAGAMI K, KINOSHITA Y, NIWA H. Genetic analysis based on next generation sequencing of Streptococcus equi subsp. equi isolated from horses imported into Japan. J Vet Med Sci 2024; 86:828-832. [PMID: 38897953 PMCID: PMC11300130 DOI: 10.1292/jvms.23-0342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 05/09/2024] [Indexed: 06/21/2024] Open
Abstract
Strangles is a globally widespread, commonly diagnosed and important infectious disease of equids caused by Streptococcus equi subsp. equi. We performed whole genome sequencing of 19 S. equi isolates collected from imported horses at the Japanese border. Of these isolates, 15 isolates were obtained from clinical cases and 4 were from subclinical cases. The 19 isolates were grouped into 3 Bayesian analysis of population structure (BAPS) groups by the core genome single nucleotide polymorphism analysis corresponding to exporting country, SeM typing, or exporter of the horses. The 19 isolates possessed same pathogenic genes regardless of clinical status in imported horses and no antimicrobial resistance genes. The disease status of the horses may rather reflect the prior exposure of animals with sub-clinical infection to S. equi.
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Affiliation(s)
- Kei NAKAJIMA
- Moji Branch Shinmoji Quarantine Facility, Animal Quarantine
Service, MAFF, Fukuoka, Japan
| | - Kazufumi KASUYA
- Microbiological Examination Division, Laboratory Department,
Animal Quarantine Service, MAFF, Kanagawa, Japan
| | - Hironobu SENBA
- Pathological and Physiochemical Examination Division,
Laboratory Department, Animal Quarantine Service, MAFF, Kanagawa, Japan
| | - Katsunori TAGAMI
- Moji Branch Shinmoji Quarantine Facility, Animal Quarantine
Service, MAFF, Fukuoka, Japan
| | - Yuta KINOSHITA
- Microbiology Division, Equine Research Institute, Japan
Racing Association, Tochigi, Japan
| | - Hidekazu NIWA
- Microbiology Division, Equine Research Institute, Japan
Racing Association, Tochigi, Japan
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Soliman R, Yousef M, Gelil SA, Aboul-Ella H. Development of novel Streptococcus equi vaccines with an assessment of their immunizing potentials and protective efficacies. BMC Vet Res 2024; 20:173. [PMID: 38702665 PMCID: PMC11067117 DOI: 10.1186/s12917-024-04012-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 04/10/2024] [Indexed: 05/06/2024] Open
Abstract
Strangles is a highly contagious disease of the equine upper respiratory tract caused by Streptococcus equi subspecies. Streptococcus equi subsp. equi (S. equi) and Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) was isolated, as local, hot, and field strains, from horses clinically suffering from respiratory distress. The isolated Streptococci were identified using bacteriological and molecular techniques. Four formulations of inactivated S. equi vaccines were developed and evaluated. The first formulation was prepared using the S. equi isolates, adjuvanted with MONTANIDE GEL adjuvant, while the second formulation was adjuvanted with MONTANIDE ISA-70 adjuvant. The other 2 formulations were inactivated combined vaccines prepared from both S. equi and S. zooepidemicus isolates. The 3rd formulation was the combined isolates adjuvanted with MONTANIDE GEL while the 4th formulation was the combined isolates adjuvanted with MONTANIDE ISA-70. The developed vaccines' physical properties, purity, sterility, safety, and potency were ensured. The immunizing efficacy was determined in isogenic BALB/c mice and white New Zealand rabbits using the passive hemagglutination test. Also, the antibodies' titer of the combined S. equi and S. zooepidemicus vaccine adjuvanted with MONTANIDE ISA-70 in foals was tracked using an indirect enzyme-linked immunosorbent assay. The protective efficacy of the developed vaccines was determined using a challenge test in both laboratory and field animal models, where a 75% protection rate was achieved. The combined vaccine proved to be more efficacious than the monovalent vaccine. Also, the MONTANIDE ISA-70 adjuvant provided significant protective efficacy than the MONTANIDE GEL. The current work is introducing a very promising mitigative and strategic controlling solution for strangles.
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Affiliation(s)
- Rafik Soliman
- Department of Microbiology, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
| | - Mohamed Yousef
- Department of Veterinary Hygiene, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
| | - Sara Abdel Gelil
- Department of Microbiology, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
| | - Hassan Aboul-Ella
- Department of Microbiology, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt.
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Zhang Y, Lv F, Su Y, Zhang H, Zhang B. Complete genome sequencing and comparative genomic analysis of three donkey Streptococcus equi subsp. equi isolates. Front Microbiol 2023; 14:1285027. [PMID: 38029076 PMCID: PMC10646407 DOI: 10.3389/fmicb.2023.1285027] [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: 08/29/2023] [Accepted: 10/10/2023] [Indexed: 12/01/2023] Open
Abstract
Introduction Streptococcus equi subspecies equi (S. equi) is the causative agent of strangles, which is one of the most common and highly contagious respiratory infectious illnesses in horses. Streptococcus equi (S. equi) is a horse-specific pathogen that originated from the closely related zoonotic pathogen Streptococcus equi subspecies zooepidemicus (S. zooepidemicus). Despite decades of research, the movement of genetic material across host-restricted diseases remains a mystery. Methods Three S. equi donkey isolates (HTP133, HTP232, and HT1112) were recently isolated from a strangles epidemic on donkey farms in China's Xinjiang Province. In this study, we performed a comprehensive comparative analysis of these isolates using whole genome sequencing and compared them to the published genomic sequences of equine strain S. equi 4047 to uncover evidence of genetic events that shaped the evolution of these donkey S. equi isolates' genomes. Results Whole genome sequencing indicated that both strains were closely related, with comparable gene compositions and a high rate of shared core genomes (1788-2004). Our comparative genomic study indicated that the genome structure is substantially conserved across three donkey strains; however, there are several rearrangements and inversions when compared to the horse isolate S. equi 4047. The virulence factors conveyed by genomic islands and prophages, in particular, played a key role in shaping the pathogenic capacity and genetic diversity of these S. equi strains. Furthermore, we discovered that the HT133 isolate had a strong colonization ability and increased motility; the HT1112 isolates had a significantly higher ability for antimicrobial resistance and biofilm formation, and the HT232 isolate gained pathogenic specialization by acquiring a bacteriophage encoding hyaluronate lyase. Discussion In summary, our findings show that genetic exchange across S. equi strains influences the development of the donkey S. equi genome, offering important genetic insights for future epidemiological studies of S. equi infection.
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Affiliation(s)
| | | | - Yan Su
- Department of Microbiology and Immunology, College of Veterinary Medicine, Xinjiang Agricultural University, Ürümqi, Xinjiang, China
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Moghaddam S, Lotfollahzadeh S, Salehi TZ, Hassanpour A, Manesh HT, Tamai IA. Molecular and sequencing study and identification of novel SeM-type in beta-hemolytic streptococci involving the upper respiratory tract in Iran. BMC Vet Res 2023; 19:210. [PMID: 37848882 PMCID: PMC10580511 DOI: 10.1186/s12917-023-03772-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 10/03/2023] [Indexed: 10/19/2023] Open
Abstract
BACKGROUND Beta-hemolytic streptococci involving the upper respiratory tract cause strangles and strangles-like diseases in horses and cause severe economic damage to the equestrian club each year. Therefore, careful epidemiological study of these bacteria, evaluation of phylogenetic connections and SeM-typing can be useful to determine the source and epidemiological characteristics of the disease outbreak. Isolates were analyzed using molecular and phylogenetic methods and to determine antibiotic resistance pattern in Iranian isolates. Molecular and phylogenetic methods were used to evaluate Iranian streptococcal isolates, and the similarity of the Iranian SeM-97 sequence with other alleles was assessed using the Neighbor-joining method with the Kimura 2 Parameter statistical model. The amino acid sequence of this gene was compared with the predicted SeM-3 reference amino acid sequence (FM204883) using MEGA 7 software. RESULTS One type of SeM was found among streptococcal isolates. This type (SeM-97) was reported for the first time and was a new SeM. The relationship between streptococcal isolates and age, sex, race, clinical signs and geographical area was investigated. A significant relationship was observed between streptococcal isolates with age variables and clinical symptoms. CONCLUSIONS In our study, a Streptococcus equi subsp. equi genotype was identified. The 97 allele of this gene has not been officially reported anywhere and is only registered in the Public databases for molecular typing and microbial genome diversity (PubMLST)-SeM database by Katy Webb. This was the first isolate reported and registered in the mentioned database. The isolate (Tabriz61) had the SeM-97 allele with clinical signs including mucopurulent discharge, abnormal sounds in lung hearing, warmth and enlargement or discharge and abscess of retropharyngeal lymph node and fever. This isolate was sensitive to penicillin, meropenem, ampicillin, cefotaxime, tetracycline, erythromycin, azithromycin, chloramphenicol, enrofloxacin and ciprofloxacin antibiotics and resistant to trimethoprim-sulfamethoxazole and gentamicin antibiotics.
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Affiliation(s)
- Sina Moghaddam
- Department of Internal Medicine, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - Samad Lotfollahzadeh
- Department of Internal Medicine, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.
| | - Taghi Zahraei Salehi
- Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - Ali Hassanpour
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Tabriz Medical Science Branch, Islamic Azad University, Tabriz, Iran
| | - Hamid Tavanaei Manesh
- Department of Internal Medicine, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - Iraj Ashrafi Tamai
- Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
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Knox A, Zerna G, Beddoe T. Current and Future Advances in the Detection and Surveillance of Biosecurity-Relevant Equine Bacterial Diseases Using Loop-Mediated Isothermal Amplification (LAMP). Animals (Basel) 2023; 13:2663. [PMID: 37627456 PMCID: PMC10451754 DOI: 10.3390/ani13162663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 08/13/2023] [Accepted: 08/15/2023] [Indexed: 08/27/2023] Open
Abstract
Horses play an important role throughout the world, whether for work, culture, or leisure, providing an ever-growing significant contribution to the economy. The increase in importation and movement of horses, both nationally and internationally, has inevitably allowed for the global equine industry to grow. Subsequently, however, the potential for transmission of fatal equine bacterial diseases has also escalated, and devasting outbreaks continue to occur. To prevent such events, disease surveillance and diagnosis must be heightened throughout the industry. Current common, or "gold-standard" techniques, have shown to be inadequate at times, thus requiring newer technology to impede outbreaks. Loop-mediated isothermal amplification (LAMP) has proven to be a reliable, rapid, and accessible tool in both diagnostics and surveillance. This review will discuss equine bacterial diseases of biosecurity relevance and their current diagnostic approaches, as well as their respective LAMP assay developments. Additionally, we will provide insight regarding newer technology and advancements associated with this technique and their potential use for the outlined diseases.
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Affiliation(s)
| | | | - Travis Beddoe
- Department of Animal, Plant and Soil Sciences, Centre for AgriBioscience, La Trobe University, Bundoora, VIC 3082, Australia; (A.K.); (G.Z.)
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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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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: 3] [Impact Index Per Article: 3.0] [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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Whitlock FM, Newton JR. A practitioner's guide to understanding infectious disease diagnostics in the United Kingdom. Part 2: Serological diagnostic testing methods and diagnostic test result interpretation. EQUINE VET EDUC 2022. [DOI: 10.1111/eve.13491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Differences in the Accessory Genomes and Methylomes of Strains of Streptococcus equi subsp. equi and of Streptococcus equi subsp. zooepidemicus Obtained from the Respiratory Tract of Horses from Texas. Microbiol Spectr 2022; 10:e0076421. [PMID: 35019696 PMCID: PMC8754150 DOI: 10.1128/spectrum.00764-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Streptococcus equi subsp. equi (SEE) is a host-restricted equine pathogen considered to have evolved from Streptococcus equi subsp. zooepidemicus (SEZ). SEZ is promiscuous in host range and is commonly recovered from horses as a commensal. Comparison of a single strain each of SEE and SEZ using whole-genome sequencing, supplemented by PCR of selected genes in additional SEE and SEZ strains, was used to characterize the evolution of SEE. But the known genetic variability of SEZ warrants comparison of the whole genomes of multiple SEE and SEZ strains. To fill this knowledge gap, we utilized whole-genome sequencing to characterize the accessory genome elements (AGEs; i.e., elements present in some SEE strains but absent in SEZ or vice versa) and methylomes of 50 SEE and 50 SEZ isolates from Texas. Consistent with previous findings, AGEs consistently found in all SEE isolates were primarily from mobile genetic elements that might contribute to host restriction or pathogenesis of SEE. Fewer AGEs were identified in SEZ because of the greater genomic variability among these isolates. The global methylation patterns of SEE isolates were more consistent than those of the SEZ isolates. Among homologous genes of SEE and SEZ, differential methylation was identified only in genes of SEE encoding proteins with functions of quorum sensing, exopeptidase activity, and transitional metal ion binding. Our results indicate that effects of genetic mobile elements in SEE and differential methylation of genes shared by SEE and SEZ might contribute to the host specificity of SEE. IMPORTANCE Strangles, caused by the host-specific bacterium Streptococcus equi subsp. equi (SEE), is the most commonly diagnosed infectious disease of horses worldwide. Its ancestor, Streptococcus equi subsp. zooepidemicus (SEZ), is frequently isolated from a wide array of hosts, including horses and humans. A comparison of the genomes of a single strain of SEE and SEZ has been reported, but sequencing of further isolates has revealed variability among SEZ strains. Thus, the importance of this study is that it characterizes genomic and methylomic differences of multiple SEE and SEZ isolates from a common geographic region (viz., Texas). Our results affirm many of the previously described differences between the genomes of SEE and SEZ, including the role of mobile genetic elements in contributing to host restriction. We also provide the first characterization of the global methylome of Streptococcus equi and evidence that differential methylation might contribute to the host restriction of SEE.
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Streptococcus equi-derived extracellular vesicles as a vaccine candidate against Streptococcus equi infection. Vet Microbiol 2021; 259:109165. [PMID: 34225054 DOI: 10.1016/j.vetmic.2021.109165] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 06/22/2021] [Indexed: 02/08/2023]
Abstract
Streptococcus equi subspecies equi is a pathogenic bacterium that causes strangles, a highly contagious respiratory infection in horses and other equines. The limitations of current vaccines against S. equi infection warrants the development of an affordable, safe, and effective vaccine. Because gram-positive extracellular vesicles (EVs) transport various immunogenic antigens, they are attractive vaccine candidates. Here, we purified the EVs of S. equi ATCC 39506 and evaluated them as a vaccine candidate against S. equi infection in mice. As an initial step, comparative proteomic analysis was performed to characterize the functional features of the EVs. Reverse vaccinology and knowledge-based annotations were then used to screen potential vaccine candidates (PVCs) for S. equi ATCC 39506. Finally, 32 PVCs were found to be enriched in the EV fraction, suggesting the usefulness of this fraction as a vaccine. Importantly, a significantly higher survival rate after S. equi infection was detected in mice immunized with S. equi-derived EVs via the intraperitoneal route than in mice immunized with heat-killed bacteria. Of note, immunoprecipitation-mass spectrometry results validated various immunogenic antigens within the EV proteome. In conclusion, our results suggest that S. equi-derived EVs can serve as a vaccine candidate against S. equi infection.
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Abstract
Historically described as a commensal of the swine upper respiratory tract, Streptococcus equi subspecies zooepidemicus was previously reported as an important swine pathogen only in Asia. Here we report the isolation and whole genome characterization of S. equi subsp. zooepidemicus associated with a sudden death outbreak in pigs in Canada.
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Differences in the genome, methylome, and transcriptome do not differentiate isolates of Streptococcus equi subsp. equi from horses with acute clinical signs from isolates of inapparent carriers. PLoS One 2021; 16:e0252804. [PMID: 34125848 PMCID: PMC8202921 DOI: 10.1371/journal.pone.0252804] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 05/21/2021] [Indexed: 12/13/2022] Open
Abstract
Streptococcus equi subsp. equi (SEE) is a host-restricted bacterium that causes the common infectious upper respiratory disease known as strangles in horses. Perpetuation of SEE infection appears attributable to inapparent carrier horses because it neither persists long-term in the environment nor infects other host mammals or vectors, and infection results in short-lived immunity. Whether pathogen factors enable SEE to remain in horses without causing clinical signs remains poorly understood. Thus, our objective was to use next-generation sequencing technologies to characterize the genome, methylome, and transcriptome of isolates of SEE from horses with acute clinical strangles and inapparent carrier horses—including isolates recovered from individual horses sampled repeatedly—to assess pathogen-associated changes that might reflect specific adaptions of SEE to the host that contribute to inapparent carriage. The accessory genome elements and methylome of SEE isolates from Sweden and Pennsylvania revealed no significant or consistent differences between acute clinical and inapparent carrier isolates of SEE. RNA sequencing of SEE isolates from Pennsylvania demonstrated no genes that were differentially expressed between acute clinical and inapparent carrier isolates of SEE. The absence of specific, consistent changes in the accessory genomes, methylomes, and transcriptomes of acute clinical and inapparent carrier isolates of SEE indicates that adaptations of SEE to the host are unlikely to explain the carrier state of SEE. Efforts to understand the carrier state of SEE should instead focus on host factors.
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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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Meningoencephalitis with Streptococcus equi Subspecies equi Leading to a Dural Arteriovenous Fistula. Case Rep Neurol Med 2021; 2021:9898364. [PMID: 34306778 PMCID: PMC8272663 DOI: 10.1155/2021/9898364] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 01/10/2021] [Accepted: 04/07/2021] [Indexed: 11/17/2022] Open
Abstract
Invasive infection with Lancefield group C streptococci in humans is extremely rare, with the vast majority of clinical isolates belonging to Streptococcus dysgalactiae subsp. equisimilis. We report a case of meningoencephalitis in a 69-year-old man caused by Streptococcus equi subsp. equi, a microbe that causes strangles in Equus caballus (i.e., the horse). This is only the fourth infection with this subtype of the central nervous system (CNS) reported in humans. The invasiveness of these bacteria, known to be capable of releasing strongly immunogenic exotoxins, is illustrated by white matter lesions that are present in the acute phase. This patient initially recovered well after treatment with antibiotics and glucocorticoids. However, the patient was readmitted 5 months later with multiple intraparenchymatous cerebral haemorrhages. Cerebral angiography confirmed the presence of a suspected superficial dural arteriovenous fistula (DAVF), which is seldom reported after CNS infection. The invasiveness of these bacteria was illustrated by white matter lesions present in the acute phase and the occurrence of a de novo dural arteriovenous fistula in the follow-up period.
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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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Bustos CP, Muñoz AJ, Guida N, Waller A, Mesplet M. Novel seM-types of Streptococcus equi subsp. equi identified in isolates circulating in Argentina. Equine Vet J 2021; 54:132-138. [PMID: 33420757 DOI: 10.1111/evj.13420] [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: 09/22/2020] [Revised: 12/09/2020] [Accepted: 01/03/2021] [Indexed: 11/29/2022]
Abstract
BACKGROUND Strangles is a worldwide infectious disease caused by Streptococcus equi subsp. equi that affects the upper respiratory tract of horses. Streptococcus equi subsp. equi characterisation by seM-typing is internationally used for epidemiological studies and comparison of isolates. OBJECTIVES To identify and to compare the seM-types of Argentinian isolates of Streptococcus equi subsp. equi. STUDY DESIGN Investigation of bacterial isolates using molecular and phylogenetic approaches. METHODS A total of 59 Argentinian isolates of Streptococcus equi subsp. equi obtained between 2007 and 2019 were studied by seM-typing. The sequence similarity of Argentinian seM-types and the other alleles available on the seM database was determined using BLAST and phylogenetic analysis was performed using the Neighbour-Joining algorithm. The amino acid sequences were predicted and compared with the predicted amino acid sequence of the reference strain 4047 using the MEGA 7 software and PROVEAN tool. RESULTS Eight seM-types were found among the isolates. Only one of them (seM-61) has been previously reported and the other seven alleles (seM-129, seM-130, seM-131, seM-132, seM-133, seM-134 and seM-135) were novel seM sequences. High genetic similarity was observed among the Argentinian seM-types, with the exception of seM-130. No functional effects of amino acid differences were predicted. MAIN LIMITATIONS The number of related and unrelated isolates per year. CONCLUSIONS Seven novel seM-types and seM-61 that were previously reported in Brazil were circulating in Argentina which were identified as circulating in Argentinian horses between 2007 and 2019. The high genetic similarity among the Argentinian and Brazilian seM-types suggests that there is a geographical distribution of strain types. The geographical restriction of strains is likely to reflect the movement of horses between different equine disciplines and neighbouring countries.
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Affiliation(s)
- Carla P Bustos
- Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Cátedra de Enfermedades Infecciosas, Ciudad Autónoma de Buenos Aires, Argentina
| | - Alejandra J Muñoz
- Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Cátedra de Enfermedades Infecciosas, Ciudad Autónoma de Buenos Aires, Argentina
| | - Nora Guida
- Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Cátedra de Enfermedades Infecciosas, Ciudad Autónoma de Buenos Aires, Argentina
| | | | - María Mesplet
- Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Cátedra de Enfermedades Infecciosas, Ciudad Autónoma de Buenos Aires, Argentina
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17
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Ivens PAS, Pirie S. Streptococcus equi subspecies equi diagnosis. Equine Vet J 2020; 53:15-17. [PMID: 32772398 DOI: 10.1111/evj.13319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 07/02/2020] [Indexed: 11/30/2022]
Affiliation(s)
- Philip A S Ivens
- Buckingham Equine Vets Ltd, Sparrow Lodge Farm, Wicken, Buckingham, UK
| | - Scott Pirie
- University of Edinburgh, Royal (Dick) School of Veterinary Studies, Veterinary Clinical Sciences, Easter Bush Campus, Easter Bush, Roslin, Midlothian, UK
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Chen X, Resende-De-Macedo N, Sitthicharoenchai P, Sahin O, Burrough E, Clavijo M, Derscheid R, Schwartz K, Lantz K, Robbe-Austerman S, Main R, Li G. Genetic characterization of Streptococcus equi subspecies zooepidemicus associated with high swine mortality in the United States. Transbound Emerg Dis 2020; 67:2797-2808. [PMID: 32460392 DOI: 10.1111/tbed.13645] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 04/21/2020] [Accepted: 05/15/2020] [Indexed: 12/22/2022]
Abstract
High mortality events due to Streptococcus equi subspecies zooepidemicus (Streptococcus zooepidemicus) in swine have not previously been reported in the United States. In September and October 2019, outbreaks with swine mortality up to 50% due to S. zooepidemicus septicaemia were reported in Ohio and Tennessee. Genomic epidemiological analysis revealed that the eight outbreak isolates were clustered together with ATCC 35246, a Chinese strain caused outbreaks with high mortality, also closely related to three isolates from human cases from Virginia, but significantly different from an outbreak-unrelated swine isolate from Arizona and most isolates from other animal species. Comparative genomic analysis on two outbreak isolates and another outbreak-unrelated isolate identified several genomic islands and virulence genes specifically in the outbreak isolates only, which are likely associated with the high mortality observed in the swine population. These findings have implications for understanding, tracking and possibly preventing diseases caused by S. zooepidemicus in swine.
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Affiliation(s)
- Xuhua Chen
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Nubia Resende-De-Macedo
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Panchan Sitthicharoenchai
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Orhan Sahin
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Eric Burrough
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Maria Clavijo
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Rachel Derscheid
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Kent Schwartz
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Kristina Lantz
- National Veterinary Services Laboratories, Ames, Iowa, USA
| | | | - Rodger Main
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Ganwu Li
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
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19
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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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20
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Durham AE, Kemp-Symonds J. Failure of serological testing for antigens A and C of Streptococcus equi subspecies equi to identify guttural pouch carriers. Equine Vet J 2020; 53:38-43. [PMID: 32374892 DOI: 10.1111/evj.13276] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 04/05/2020] [Accepted: 04/23/2020] [Indexed: 01/08/2023]
Abstract
BACKGROUND Serology is commonly used as a means of identifying horses that might be chronic and silent carriers of S. equi but its sensitivity is rarely examined. OBJECTIVES The study was designed to investigate the sensitivity of serological testing for antibodies against S. equi antigens A and C to detect guttural pouch carriers of S. equi. STUDY DESIGN Retrospective clinical study. METHODS As part of routine surveillance and quarantine procedures horses arriving at a welfare charity quarantine unit were subject to both microbiological sampling of guttural pouches and also serological testing for antibodies directed at S. equi antigens A and C. Laboratory results and endoscopic findings were examined to determine associations between serological results and guttural pouch carriage of S. equi. RESULTS Of 287 included horses, 9 (3.1%) were found to be guttural pouch carriers. There was no significant association between serological status and guttural pouch carriage of S. equi Only one of the nine carriers (11%) was seropositive using a cut-off of OD ≥ 0.5, and only three of nine (33%) using a cut-off of OD ≥ 0.3. MAIN LIMITATIONS Horses examined in this study were new arrivals at a welfare centre rather than from a general, well-managed, equid population. As a retrospective clinical study, the laboratory test results could not be repeated for further confirmation. CONCLUSIONS Caution is advised when relying on seronegativity to antigens A and C in order to discount the possibility of chronic carriage of S. equi in guttural pouches.
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21
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Tartor YH, El-Naenaeey ESY, Gharieb NM, Ali WS, Ammar AM. Novel Streptococcus equi strains causing strangles outbreaks in Arabian horses in Egypt. Transbound Emerg Dis 2020; 67:2455-2466. [PMID: 32304282 DOI: 10.1111/tbed.13584] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 04/04/2020] [Accepted: 04/06/2020] [Indexed: 11/28/2022]
Abstract
Strangles displays a major challenge to veterinary medicine worldwide. However, no data on Streptococcus equi subsp. equi (S. equi) M protein alleles have been reported so far from Arabian horses. We report here for the first time the S. equi SeM alleles causing strangles in Arabian horses, and the associated risk factors for the disease. Duplicate samples from one hundred Arabian horses with acute strangles in confirmed outbreaks and sporadic cases were analysed by phenotypic methods and multiplex polymerase chain reaction (PCR) targeting streptokinase precursor, seeI and sodA genes. PCR and sequencing of S. equi SeM gene were employed for strains typing, and the four superantigens were determined among the allelic variants. Direct-sample PCR confirmed and highly positively correlated (r = .85) with the phenotypic results, and detected S. equi in five samples more than the conventional culture. A combination of multiplex PCR from samples and culture could successfully identify S. equi (92%), S. zooepidemicus (5%) and S. equisimilis (3%). SeM typing demonstrated five SeM alleles, including four previously unidentified alleles that were deposited in the PubMLST-SeM database. SeM-139 and SeM-141 are related to some strains that were recently recovered from donkeys in China. SeM-140 and SeM-199 are related to a group of alleles from horses in Europe. Variation in the presence of seeM, seeH and seeL superantigens was found across the four novel alleles without interference with the severity of strangles and clinical presentation seen in different outbreaks. Horse age was the most important factor in developing strangles, followed by seasonality and the diagnosis of strangles in the previous year. These new findings comprise a significant contribution to the horse industry through the identification of novel S. equi SeM types that may bolster measures for strangles control as the identified SeM alleles will certainly help in the development of SeM-containing vaccine.
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Affiliation(s)
- Yasmine H Tartor
- Department of Microbiology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, 44511, Egypt
| | - El-Sayed Y El-Naenaeey
- Department of Microbiology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, 44511, Egypt
| | - Nesreen M Gharieb
- Department of Animal Management and Treatment, Kafr Saqr Veterinary Administration, Sharkia Governorate, Zagazig, Egypt
| | - Wessam S Ali
- Department of Animal Management and Treatment, Diarb Negm Veterinary Administration, Sharkia Governorate, Zagazig, Egypt
| | - Ahmed M Ammar
- Department of Microbiology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, 44511, Egypt
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22
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Charbonneau ARL, Taylor E, Mitchell CJ, Robinson C, Cain AK, Leigh JA, Maskell DJ, Waller AS. Identification of genes required for the fitness of Streptococcus equi subsp. equi in whole equine blood and hydrogen peroxide. Microb Genom 2020; 6:e000362. [PMID: 32228801 PMCID: PMC7276704 DOI: 10.1099/mgen.0.000362] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 03/12/2020] [Indexed: 12/25/2022] Open
Abstract
The availability of next-generation sequencing techniques provides an unprecedented opportunity for the assignment of gene function. Streptococcus equi subspecies equi is the causative agent of strangles in horses, one of the most prevalent and important diseases of equids worldwide. However, the live attenuated vaccines that are utilized to control this disease cause adverse reactions in some animals. Here, we employ transposon-directed insertion-site sequencing (TraDIS) to identify genes that are required for the fitness of S. equi in whole equine blood or in the presence of H2O2 to model selective pressures exerted by the equine immune response during infection. We report the fitness values of 1503 and 1471 genes, representing 94.5 and 92.5 % of non-essential genes in S. equi, following incubation in whole blood and in the presence of H2O2, respectively. Of these genes, 36 and 15 were identified as being important to the fitness of S. equi in whole blood or H2O2, respectively, with 14 genes being important in both conditions. Allelic replacement mutants were generated to validate the fitness results. Our data identify genes that are important for S. equi to resist aspects of the immune response in vitro, which can be exploited for the development of safer live attenuated vaccines to prevent strangles.
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Affiliation(s)
- Amelia R. L. Charbonneau
- Animal Health Trust, Lanwades Park, Newmarket, Suffolk, UK
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Emma Taylor
- Animal Health Trust, Lanwades Park, Newmarket, Suffolk, UK
- School of Veterinary Medicine, University of Surrey, Guildford, UK
| | | | - Carl Robinson
- Animal Health Trust, Lanwades Park, Newmarket, Suffolk, UK
| | - Amy K. Cain
- Department of Molecular Sciences, Macquarie University, Sydney, Australia
| | - James A. Leigh
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Leicestershire, UK
| | - Duncan J. Maskell
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
- University of Melbourne, Victoria, Australia
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23
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Comparison of whole genome sequences of Streptococcus equi subsp. equi from an outbreak in Texas with isolates from within the region, Kentucky, USA, and other countries. Vet Microbiol 2020; 243:108638. [PMID: 32273017 DOI: 10.1016/j.vetmic.2020.108638] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 03/03/2020] [Accepted: 03/05/2020] [Indexed: 12/22/2022]
Abstract
Strangles, caused by Streptococcus equi subspecies equi (S. equi) is an infectious disease of horses with worldwide distribution, but there are limited data available regarding strain variation using whole genome sequencing among and within outbreaks in the United States (US), and how US isolates compare with S. equi isolated globally. To address this knowledge-gap, we compared the whole genomes of 54 S. equi isolates from Texas and Kentucky and those of 230 publicly available sequences of S. equi isolates collected from other countries. Our results show that despite minimal variation among isolates within an outbreak some mutations do occur among individual outbreak isolates. Some S. equi strains from the US are closely related to S. equi isolates from other countries, likely reflecting international dissemination of isolates. Collectively, these data improve our understanding of phenotypic and genotypic variation of isolates within an outbreak, and the international distribution of S. equi. We also identify a novel variant of the S. equi M-protein, and observed cases of strangles that were caused by the modified-live vaccine but that were not recognized as vaccine-associated at the time of clinical sample submission.
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24
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D'Gama JD, Ma Z, Zhang H, Liu X, Fan H, Morris ERA, Cohen ND, Cywes-Bentley C, Pier GB, Waldor MK. A Conserved Streptococcal Virulence Regulator Controls the Expression of a Distinct Class of M-Like Proteins. mBio 2019; 10:e02500-19. [PMID: 31641092 PMCID: PMC6805998 DOI: 10.1128/mbio.02500-19] [Citation(s) in RCA: 5] [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: 09/19/2019] [Accepted: 09/23/2019] [Indexed: 12/16/2022] Open
Abstract
Streptococcus equi subspecies zooepidemicus (SEZ) are group C streptococci that are important pathogens of economically valuable animals such as horses and pigs. Here, we found that many SEZ isolates bind to a monoclonal antibody that recognizes poly-N-acetylglucosamine (PNAG), a polymer that is found as a surface capsule-like structure on diverse microbes. A fluorescence-activated cell sorting-based transposon insertion sequencing (Tn-seq) screen, coupled with whole-genome sequencing, was used to search for genes for PNAG biosynthesis. Surprisingly, mutations in a gene encoding an M-like protein, szM, and the adjacent transcription factor, designated sezV, rendered strains PNAG negative. SezV was required for szM expression and transcriptome analysis showed that SezV has a small regulon. SEZ strains with inactivating mutations in either sezV or szM were highly attenuated in a mouse model of infection. Comparative genomic analyses revealed that linked sezV and szM homologues are present in all SEZ, S. equi subspecies equi (SEE), and M18 group A streptococcal (GAS) genomes in the database, but not in other streptococci. The antibody to PNAG bound to a wide range of SEZ, SEE, and M18 GAS strains. Immunochemical studies suggest that the SzM protein may be decorated with a PNAG-like oligosaccharide although an intact oligosaccharide substituent could not be isolated. Collectively, our findings suggest that the szM and sezV loci define a subtype of virulent streptococci and that an antibody to PNAG may have therapeutic applications in animal and human diseases caused by streptococci bearing SzM-like proteins.IMPORTANCE M proteins are surface-anchored virulence factors in group A streptococci, human pathogens. Here, we identified an M-like protein, SzM, and its positive regulator, SezV, in Streptococcus equi subspecies zooepidemicus (SEZ), an important group of pathogens for domesticated animals, including horses and pigs. SzM and SezV homologues were found in the genomes of all SEZ and S. equi subspecies equi and M18 group A streptococcal strains analyzed but not in other streptococci. Mutant SEZ strains lacking either sezV or szM were highly attenuated in a mouse model of infection. Collectively, our findings suggest that SezV-related regulators and the linked SzM family of M-like proteins define a new subset of virulent streptococci.
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Affiliation(s)
- Jonathan D D'Gama
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Zhe Ma
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, Massachusetts, USA
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
- Ministry of Agriculture Key Laboratory of Animal Bacteriology, Nanjing, Jiangsu, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu, China
| | - Hailong Zhang
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Xu Liu
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Hongjie Fan
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
- Ministry of Agriculture Key Laboratory of Animal Bacteriology, Nanjing, Jiangsu, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu, China
| | - Ellen Ruth A Morris
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, College Station, Texas, USA
| | - Noah D Cohen
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, College Station, Texas, USA
| | - Colette Cywes-Bentley
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Gerald B Pier
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Matthew K Waldor
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, Massachusetts, USA
- Howard Hughes Medical Institute, Boston, Massachusetts, USA
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25
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Turner CE, Bubba L, Efstratiou A. Pathogenicity Factors in Group C and G Streptococci. Microbiol Spectr 2019; 7:10.1128/microbiolspec.gpp3-0020-2018. [PMID: 31111818 PMCID: PMC11026075 DOI: 10.1128/microbiolspec.gpp3-0020-2018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Indexed: 11/20/2022] Open
Abstract
Initially recognized zoonoses, streptococci belonging to Lancefield group C (GCS) and G (GGS) were subsequently recognised as human pathogens causing a diverse range of symptoms, from asymptomatic carriage to life threatening diseases. Their taxonomy has changed during the last decade. Asymptomatic carriage is <4% amongst the human population and invasive infections are often in association with chronic diseases such as diabetes, cardiovascular diseases or chronic skin infections. Other clinical manifestations include acute pharyngitis, pneumonia, endocarditis, bacteraemia and toxic-shock syndrome. Post streptococcal sequalae such as rheumatic fever and acute glomerulonephritis have also been described but mainly in developed countries and amongst specific populations. Putative virulence determinants for these organisms include adhesins, toxins, and other factors that are essential for dissemination in human tissues and for interference with the host immune responses. High nucleotide similarities among virulence genes and their association with mobile genetic elements supports the hypothesis of extensive horizontal gene transfer events between the various pyogenic streptococcal species belonging to Lancefield groups A, C and G. A better understanding of the mechanisms of pathogenesis should be apparent by whole-genome sequencing, and this would result in more effective clinical strategies for the pyogenic group in general.
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Affiliation(s)
- Claire E Turner
- Department of Molecular Biology & Biotechnology, The Florey Institute, University of Sheffield, Sheffield, UK
| | - Laura Bubba
- Reference Microbiology Division, National Infection Service, Public Health England, London, United Kingdom
- European Programme for Public Health Microbiology Training (EUPHEM), European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden
| | - Androulla Efstratiou
- Reference Microbiology Division, National Infection Service, Public Health England, London, United Kingdom
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26
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Kasuya K, Tanaka N, Oshima F, Fujisawa N, Saito M, Tagami K, Niwa H, Sasai K. Genetic analysis of Streptococcus equi subsp. equi isolated from horses imported into Japan. J Vet Med Sci 2019; 81:924-927. [PMID: 31019139 PMCID: PMC6612491 DOI: 10.1292/jvms.18-0656] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Strangles is a commonly diagnosed and important infectious disease of equids worldwide,
caused by Streptococcus equi subsp. equi. We determined
the SeM genotypes of S. equi isolated from imported horses at the
Japanese border within the past 8 years, which allowed us to classify 12 strains isolated
from these horses from each exporter into four allelic groups. These alleles were
different from the alleles of past isolates found in Japan. Furthermore, four strains
classified into the same allele were isolated from horses from one exporter over several
years. In this study, S. equi isolates from different exporters had
different SeM alleles. Attention to the hygiene status of farms will be necessary to
prevent the incursion of strangles.
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Affiliation(s)
- Kazufumi Kasuya
- Moji Branch Shinmoji Quarantine Facility, Animal Quarantine Service, MAFF, 3-1-2 Shinmojikita, Moji, Kitakyushu, Fukuoka 800-0113, Japan
| | - Nobuyuki Tanaka
- Moji Branch Shinmoji Quarantine Facility, Animal Quarantine Service, MAFF, 3-1-2 Shinmojikita, Moji, Kitakyushu, Fukuoka 800-0113, Japan
| | - Fumi Oshima
- Moji Branch Shinmoji Quarantine Facility, Animal Quarantine Service, MAFF, 3-1-2 Shinmojikita, Moji, Kitakyushu, Fukuoka 800-0113, Japan
| | - Nozomi Fujisawa
- Moji Branch Shinmoji Quarantine Facility, Animal Quarantine Service, MAFF, 3-1-2 Shinmojikita, Moji, Kitakyushu, Fukuoka 800-0113, Japan
| | - Megumi Saito
- Moji Branch Kagoshima Airport Sub-branch, Animal Quarantine Service, MAFF, 1590-5 Kareigawa, Hayatocho, Kirishima, Kagoshima, 899-5113, Japan
| | - Katsunori Tagami
- Moji Branch Shinmoji Quarantine Facility, Animal Quarantine Service, MAFF, 3-1-2 Shinmojikita, Moji, Kitakyushu, Fukuoka 800-0113, Japan
| | - Hidekazu Niwa
- Equine Research Institute, Japan Racing Association, 1400-4 Shiba, Shimotsuke, Tochigi 329-0412, Japan
| | - Kazumi Sasai
- Laboratory of Veterinary Internal Medicine, Division of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-oraikita, Izumisano, Osaka 598-8531, Japan
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27
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Dong J, Gao N, Waller AS, Cook FR, Fan S, Yuan D, Du Y, Li F, Norimine J, Zhu W. An outbreak of strangles associated with a novel genotype of Streptococcus equi subspecies equi in donkeys in China during 2018. Equine Vet J 2019; 51:743-748. [PMID: 30900775 DOI: 10.1111/evj.13114] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 03/15/2019] [Indexed: 11/30/2022]
Abstract
BACKGROUND Strangles is a highly contagious respiratory disease of equids caused by the bacterium Streptococcus equi subspecies equi. OBJECTIVES To identify the cause of an outbreak of strangles that occurred on donkey farms within the Shandong Province of China and determine the prevalence of the disease. STUDY DESIGN Cross-sectional. METHODS Samples were taken from clinically affected animals to measure the prevalence of strangles within the population of donkeys at six intensive farms in China and identify the SeM type of isolate recovered from affected animals. Diagnosis was confirmed by bacterial isolation, biochemical tests and PCR. Epidemiological data were analysed using Chi-square test and a Fisher's exact two-sided test. The SeM gene of S. equi isolates recovered from affected animals was determined and compared with the SeM database PubMLST-seM. RESULTS In July and August 2018, an outbreak of strangles occurred on six donkey farms within the Shandong Province of China. The overall prevalence of disease within the different donkey herds was 13.4%. Younger animals were worst affected with 40.3% (83/206) of donkey foals aged under 1 year exhibiting clinical signs compared with 12.5% (191/1525) of donkeys aged one to 2 years and 3.8% (17/442) of donkeys over 2 years of age. Analysis of SeM sequencing data identified that the farms were affected by the same strain of S. equi, SD201807, which contains the novel 136 allele of SeM. MAIN LIMITATIONS Healthy donkeys were not sampled in this study. CONCLUSIONS The number of intensive donkey breeding farms in China has risen recently. The higher numbers of animals that are in closer proximity to one another raise the potential for the transmission of infectious diseases such as strangles. This is the first description of a strangles outbreak among donkey herds in China. The Summary is available in Chinese - see Supporting information.
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Affiliation(s)
- J Dong
- Department of Veterinary Medical Science, Shandong Vocational Animal Science and Veterinary College, Weifang, China.,Shandong Donkey Industry Technology Collaborative Innovation Center, College of Agronomy, Liaocheng University, Liaocheng, China.,Center for Animal Disease Control, University of Miyazaki, Miyazaki, Japan
| | - N Gao
- Department of Veterinary Medical Science, Shandong Vocational Animal Science and Veterinary College, Weifang, China
| | | | - F R Cook
- Department of Veterinary Science, Gluck Equine Research Center, University of Kentucky, Lexington, Kentucky, USA
| | - S Fan
- Department of Veterinary Medical Science, Shandong Vocational Animal Science and Veterinary College, Weifang, China
| | - D Yuan
- Department of Veterinary Medical Science, Shandong Vocational Animal Science and Veterinary College, Weifang, China
| | - Y Du
- Department of Veterinary Medical Science, Shandong Vocational Animal Science and Veterinary College, Weifang, China
| | - F Li
- Department of Veterinary Medical Science, Shandong Vocational Animal Science and Veterinary College, Weifang, China
| | - J Norimine
- Center for Animal Disease Control, University of Miyazaki, Miyazaki, Japan
| | - W Zhu
- Department of Veterinary Medical Science, Shandong Vocational Animal Science and Veterinary College, Weifang, China.,Shandong Donkey Industry Technology Collaborative Innovation Center, College of Agronomy, Liaocheng University, Liaocheng, China
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28
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Long term dynamics of a Streptococcus equi ssp equi outbreak, assessed by qPCR and culture and seM sequencing in silent carriers of strangles. Vet Microbiol 2018; 223:107-112. [DOI: 10.1016/j.vetmic.2018.07.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 07/17/2018] [Accepted: 07/21/2018] [Indexed: 11/22/2022]
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29
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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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30
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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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31
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Steward KF, Robinson C, Maskell DJ, Nenci C, Waller AS. Investigation of the Fim1 putative pilus locus of Streptococcus equi subspecies equi. MICROBIOLOGY-SGM 2017; 163:1217-1228. [PMID: 28749324 DOI: 10.1099/mic.0.000506] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The Gram-positive bacterium Streptococcus equi subspecies equi (S. equi) is the causative agent of strangles, among the most frequently diagnosed infectious diseases of horses worldwide. Genome analysis of S. equi strain 4047 (Se4047) identified a putative operon, Fim1, with similarity to the pilus loci of other Gram-positive bacteria. The Fim1 locus was present in all strains of S. equi and its close relative S. equi subspecies zooepidemicus (S. zooepidemicus) that have been studied to date. In this study we provide evidence that the putative structural pilus proteins, SEQ_0936 and CNE, are produced on the cell surface during in vitro growth and in vivo infection. Although the proteins encoded within the Fim1 locus are not essential for attachment or biofilm formation, over-transcription of SEQ_0936 and CNE enhanced attachment to equine tissue in vitro. Our data suggest that whilst the Fim1 locus does not produce a polymerized pilus structure, the products of the Fim1 locus may fulfil an adhesive function. The putative pilus-associated regulator, tetR, which contains a nonsense mutation in S. equi, was able to regulate transcription of the Fim1 locus following repair and over-transcription, confirming its predicted role in the operon.
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Affiliation(s)
- Karen Frances Steward
- Centre of Preventative Medicine, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, UK
| | - Carl Robinson
- Centre of Preventative Medicine, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, UK
| | - Duncan J Maskell
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Chiara Nenci
- Elanco Animal Health, c/o Novartis Animal Health, Inc., Schwarzwaldallee 215, 4058 Basel, Swizerland
| | - Andrew Stephen Waller
- Centre of Preventative Medicine, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, UK
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32
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Waller AS. Science-in-brief: Streptococcus zooepidemicus: a versatile opportunistic pathogen that hedges its bets in horses. Equine Vet J 2017; 49:146-148. [PMID: 28177154 DOI: 10.1111/evj.12658] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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33
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First Report of Molecular Characterization of Argentine Isolates of Streptococcus equi subsp. equi by Pulsed-Field Gel Electrophoresis. J Equine Vet Sci 2017. [DOI: 10.1016/j.jevs.2017.01.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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34
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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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35
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Magi GE, Arias MP, Vincenzetti SV, Attili AR, Cuteri V, Preziuso S, Waller AS, Rossi G. Adhesion of Streptococcus equi to Air–Liquid Interface Ex Vivo Cultures of the Equine Guttural Pouch Mucosa Is Inhibited by Heparin. J Equine Vet Sci 2016. [DOI: 10.1016/j.jevs.2016.03.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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36
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Livengood JL, Lanka S, Maddox C, Tewari D. Detection and differentiation of wild-type and a vaccine strain of Streptococcus equi ssp. equi using pyrosequencing. Vaccine 2016; 34:3935-7. [PMID: 27317457 DOI: 10.1016/j.vaccine.2016.06.035] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Revised: 04/21/2016] [Accepted: 06/07/2016] [Indexed: 10/21/2022]
Abstract
Streptococcus equi subspecies equi (S. equi), the causative agent of strangles, is an important equine pathogen. Strangles is a highly contagious disease and a commercial modified live vaccine (MLV) is used for protection, which although effective, may also result in clinical signs of the disease. A rapid means to differentiate between the MLV and wild-type infection is crucial for quarantine release and limiting the disease spread. This study describes the use of a pyrosequencing assay targeting a single nucleotide deletion upstream of the SzPSe gene to distinguish between the wild-type and vaccine strains. A set of 96 characterized clinical specimens and isolates were tested using the assay. The assay was successful in differentiating between wild-type S. equi and the vaccine strains and in discriminating S. equi from other Streptococci. The vaccine strain was identified in 61.7% (29/47) of the strangles cases in horses with a history of MLV vaccination.
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Affiliation(s)
- Julia L Livengood
- Pennsylvania Veterinary Laboratory, 2305 N Cameron Street, Harrisburg 17110, United States
| | - Saraswathi Lanka
- Veterinary Diagnostic Laboratory, University of Illinois College of Veterinary Medicine, 2001 S. Lincoln Avenue, Urbana, IL 61802, United States
| | - Carol Maddox
- Pathobiology Department, University of Illinois College of Veterinary Medicine, 2001 S. Lincoln Avenue, Urbana, IL 61802, United States
| | - Deepanker Tewari
- Pennsylvania Veterinary Laboratory, 2305 N Cameron Street, Harrisburg 17110, United States.
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37
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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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38
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Tonpitak W, Sornklien C, Wutthiwithayaphong S. Characterization of a Streptococcus equi ssp. equi Isolate From a Strangles Outbreak in Thailand. J Equine Vet Sci 2016. [DOI: 10.1016/j.jevs.2016.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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39
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Libardoni F, Machado G, Gressler LT, Kowalski AP, Diehl GN, dos Santos LC, Corbellini LG, de Vargas AC. Prevalence of Streptococcus equi subsp. equi in horses and associated risk factors in the State of Rio Grande do Sul, Brazil. Res Vet Sci 2015; 104:53-7. [PMID: 26850537 DOI: 10.1016/j.rvsc.2015.11.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 11/01/2015] [Accepted: 11/12/2015] [Indexed: 11/28/2022]
Abstract
The aim of this study was to estimate the prevalence of equine strangles and to identify associated risk factors for this disease through a cross-sectional study of nasal swabs. Nasal swabs (n=1010) from healthy equines (absence of nasal discharge, lymphadenopathy and cough) from 341 farms were plated on 5% blood agar; of these horses, 24 were identified as positive for Streptococcus equi through isolation, PCR and DNA sequencing. The estimated prevalence for individual animals was 2.3%, and for herds, it was 5.86%. Statistical analysis identified the following as associated risk factors: the number of group events that were attended by the equines (PR: 1.06); the sharing of food containers (PR: 3.74); and at least one previous positive diagnosis of strangles on the farm (PR: 3.20). These results constitute an epidemiological contribution to the horse industry and may support measures for the future control of the disease.
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Affiliation(s)
- Felipe Libardoni
- Laboratory of Bacteriology, Federal University of Santa Maria (UFSM), Av. Roraima n° 1000, Cidade Universitária, Bairro Camobi, CEP: 97105-900 Santa Maria, RS, Brazil
| | - Gustavo Machado
- Laboratory of Veterinary Epidemiology, Faculty of Veterinary, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9090, CEP: 91540-000 Porto Alegre, RS, Brazil
| | - Letícia Trevisan Gressler
- Laboratory of Bacteriology, Federal University of Santa Maria (UFSM), Av. Roraima n° 1000, Cidade Universitária, Bairro Camobi, CEP: 97105-900 Santa Maria, RS, Brazil
| | - Ananda Paula Kowalski
- Laboratory of Bacteriology, Federal University of Santa Maria (UFSM), Av. Roraima n° 1000, Cidade Universitária, Bairro Camobi, CEP: 97105-900 Santa Maria, RS, Brazil
| | - Gustavo Nogueira Diehl
- Secretary of Agriculture, Livestock and Agribusiness of State of Rio Grande do Sul (SEAPA-RS), Brazil, Av. Getúlio Vargas, 1384, CEP: 95150-900 Porto Alegre, RS, Brazil
| | - Lucila Carboneiro dos Santos
- Secretary of Agriculture, Livestock and Agribusiness of State of Rio Grande do Sul (SEAPA-RS), Brazil, Av. Getúlio Vargas, 1384, CEP: 95150-900 Porto Alegre, RS, Brazil
| | - Luis Gustavo Corbellini
- Laboratory of Veterinary Epidemiology, Faculty of Veterinary, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9090, CEP: 91540-000 Porto Alegre, RS, Brazil
| | - Agueda Castagna de Vargas
- Laboratory of Bacteriology, Federal University of Santa Maria (UFSM), Av. Roraima n° 1000, Cidade Universitária, Bairro Camobi, CEP: 97105-900 Santa Maria, RS, Brazil.
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40
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Comparison of specificities of serum antibody responses of horses to clinical infections caused by Streptococcus equi or zooepidemicus. Vet Microbiol 2015; 180:253-9. [DOI: 10.1016/j.vetmic.2015.09.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 09/04/2015] [Accepted: 09/09/2015] [Indexed: 11/20/2022]
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41
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Harris SR, Robinson C, Steward KF, Webb KS, Paillot R, Parkhill J, Holden MTG, Waller AS. Genome specialization and decay of the strangles pathogen, Streptococcus equi, is driven by persistent infection. Genome Res 2015; 25:1360-71. [PMID: 26160165 PMCID: PMC4561494 DOI: 10.1101/gr.189803.115] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 07/01/2015] [Indexed: 11/25/2022]
Abstract
Strangles, the most frequently diagnosed infectious disease of horses worldwide, is caused by Streptococcus equi. Despite its prevalence, the global diversity and mechanisms underlying the evolution of S. equi as a host-restricted pathogen remain poorly understood. Here, we define the global population structure of this important pathogen and reveal a population replacement in the late 19th or early 20th Century. Our data reveal a dynamic genome that continues to mutate and decay, but also to amplify and acquire genes despite the organism having lost its natural competence and become host-restricted. The lifestyle of S. equi within the horse is defined by short-term acute disease, strangles, followed by long-term infection. Population analysis reveals evidence of convergent evolution in isolates from post-acute disease samples as a result of niche adaptation to persistent infection within a host. Mutations that lead to metabolic streamlining and the loss of virulence determinants are more frequently found in persistent isolates, suggesting that the pathogenic potential of S. equi reduces as a consequence of long-term residency within the horse post-acute disease. An example of this is the deletion of the equibactin siderophore locus that is associated with iron acquisition, which occurs exclusively in persistent isolates, and renders S. equi significantly less able to cause acute disease in the natural host. We identify several loci that may similarly be required for the full virulence of S. equi, directing future research toward the development of new vaccines against this host-restricted pathogen.
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Affiliation(s)
- Simon R Harris
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom
| | - Carl Robinson
- The Animal Health Trust, Lanwades Park, Kentford, Newmarket CB8 7UU, United Kingdom
| | - Karen F Steward
- The Animal Health Trust, Lanwades Park, Kentford, Newmarket CB8 7UU, United Kingdom
| | - Katy S Webb
- The Animal Health Trust, Lanwades Park, Kentford, Newmarket CB8 7UU, United Kingdom
| | - Romain Paillot
- The Animal Health Trust, Lanwades Park, Kentford, Newmarket CB8 7UU, United Kingdom
| | - Julian Parkhill
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom
| | - Matthew T G Holden
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom; School of Medicine, University of St Andrews, North Haugh, St. Andrews KY16 9TF, United Kingdom
| | - Andrew S Waller
- The Animal Health Trust, Lanwades Park, Kentford, Newmarket CB8 7UU, United Kingdom
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42
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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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Waller AS. New perspectives for the diagnosis, control, treatment, and prevention of strangles in horses. Vet Clin North Am Equine Pract 2014; 30:591-607. [PMID: 25300634 DOI: 10.1016/j.cveq.2014.08.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Strangles, characterized by abscessation of the lymph nodes of the head and neck, is the most frequently diagnosed infectious disease of horses worldwide. The persistence of the causative agent, Streptococcus equi, in a proportion of convalescent horses plays a critical role in the recurrence and spread of disease. Recent research has led to the development of effective diagnostic tests that assist the eradication of S equi from local horse populations. This article describes how these advances have been made and provides advice to assist the resolution and prevention of outbreaks. New perspectives on preventative vaccines and therapeutic interventions are discussed.
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Affiliation(s)
- Andrew S Waller
- Centre for Preventive Medicine, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, UK.
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Patty OA, Cursons RTM. The molecular identification ofStreptococcus equisubsp.equistrains isolated within New Zealand. N Z Vet J 2013; 62:63-7. [DOI: 10.1080/00480169.2013.841536] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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45
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Robinson C, Steward KF, Potts N, Barker C, Hammond TA, Pierce K, Gunnarsson E, Svansson V, Slater J, Newton JR, Waller AS. Combining two serological assays optimises sensitivity and specificity for the identification of Streptococcus equi subsp. equi exposure. Vet J 2013; 197:188-91. [DOI: 10.1016/j.tvjl.2013.01.033] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 01/25/2013] [Accepted: 01/29/2013] [Indexed: 11/29/2022]
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46
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Scott Pirie R. One is good … two are better: breaking the 'stranglehold' of asymptomatic carriers on Streptococcus equi dissemination? Vet J 2013; 197:527-8. [PMID: 23769455 DOI: 10.1016/j.tvjl.2013.04.029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 04/23/2013] [Indexed: 10/26/2022]
Affiliation(s)
- R Scott Pirie
- Royal (Dick) School of Veterinary Studies/Roslin Institute, Easter Bush Veterinary Centre, Easter Bush, Roslin Midlothian EH25 9RG, UK.
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47
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Moloney E, Kavanagh KS, Buckley TC, Cooney JC. Lineages of Streptococcus equi ssp. equi in the Irish equine industry. Ir Vet J 2013; 66:10. [PMID: 23731628 PMCID: PMC3679875 DOI: 10.1186/2046-0481-66-10] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Accepted: 05/24/2013] [Indexed: 11/19/2022] Open
Abstract
Background Streptococcus equi ssp. equi is the causative agent of ‘Strangles’ in horses. This is a debilitating condition leading to economic loss, yard closures and cancellation of equestrian events. There are multiple genotypes of S. equi ssp. equi which can cause disease, but to date there has been no systematic study of strains which are prevalent in Ireland. This study identified and classified Streptococcus equi ssp. equi strains isolated from within the Irish equine industry. Results Two hundred veterinary isolates were subjected to SLST (single locus sequence typing) based on an internal sequence from the seM gene of Streptococcus equi ssp equi. Of the 171 samples which successfully gave an amplicon, 162 samples (137 Irish and 24 UK strains) gave robust DNA sequence information. Analysis of the sequences allowed division of the isolates into 19 groups, 13 of which contain at least 2 isolates and 6 groups containing single isolates. There were 19 positions where a DNA SNP (single nucleotide polymorphism) occurs, and one 3 bp insertion. All groups had multiple (2–8) SNPs. Of the SNPs 17 would result in an amino acid change in the encoded protein. Interestingly, the single isolate EI8, which has 6 SNPs, has the three base pair insertion which is not seen in any other isolate, this would result in the insertion of an Ile residue at position 62 in that protein sequence. Comparison of the relevant region in the determined sequences with the UK Streptococcus equi seM MLST database showed that Group B (15 isolates) and Group I (2 isolates), as well as the individual isolates EI3 and EI8, are unique to Ireland, and some groups are most likely of UK origin (Groups F and M), but many more probably passed back and forth between the two countries. Conclusions The strains occurring in Ireland are not clonal and there is a considerable degree of sequence variation seen in the seM gene. There are two major clades causing infection in Ireland and these strains are also common in the UK.
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Affiliation(s)
- Emma Moloney
- Department of Life Sciences, University of Limerick, Limerick, Ireland
| | | | - Tom C Buckley
- Irish Equine Centre, Johnstown, Naas, Co. Kildare, Ireland
| | - Jakki C Cooney
- Department of Life Sciences, University of Limerick, Limerick, Ireland ; Materials and Surface Sciences Institute, University of Limerick, Limerick, Ireland
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48
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Waller AS. Strangles: taking steps towards eradication. Vet Microbiol 2013; 167:50-60. [PMID: 23642414 DOI: 10.1016/j.vetmic.2013.03.033] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Revised: 03/26/2013] [Accepted: 03/29/2013] [Indexed: 10/27/2022]
Abstract
Strangles, caused by the host adapted Lancefield group C bacterium Streptococcus equi sub-species equi (S. equi), is one of the oldest recognised infectious diseases of horses and continues to cause significant welfare and economic cost throughout the world. The ability of S. equi to establish sub-clinical persistent infections primarily in the guttural pouches of convalescent horses has been instrumental to its success. However, the implementation of simple control measures that permit the identification and treatment of persistently infected carriers can prevent further outbreaks of disease at a local level. This review summarises some of the molecular mechanisms exploited by S. equi to cause disease. New qPCR and iELISA diagnostic tests replace culture methodologies as the gold standard for the detection of infected animals. A strategy to maximise the effective application of these tests to direct management methods for the eradication of S. equi infection is presented and the role of preventative vaccines is discussed. In contrast to current understanding, emerging data illustrates the dynamism of the global S. equi population and potential consequences for the effectiveness of currently available vaccines. The ability to use modern vaccines alongside conventional biosecurity and screening procedures will be critical to the large-scale prevention and even eradication of strangles, providing an opportunity to finally break the stranglehold that this disease has on the world's equine industry.
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Affiliation(s)
- Andrew S Waller
- Centre for Preventive Medicine, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, United Kingdom.
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49
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Diversity of seM in Streptococcus equi subsp. equi isolated from strangles outbreaks. Vet Microbiol 2013; 162:663-669. [DOI: 10.1016/j.vetmic.2012.09.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Revised: 09/06/2012] [Accepted: 09/08/2012] [Indexed: 11/22/2022]
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50
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Webb K, Barker C, Harrison T, Heather Z, Steward KF, Robinson C, Newton JR, Waller AS. Detection of Streptococcus equi subspecies equi using a triplex qPCR assay. Vet J 2012; 195:300-4. [PMID: 22884566 PMCID: PMC3611602 DOI: 10.1016/j.tvjl.2012.07.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Revised: 06/12/2012] [Accepted: 07/07/2012] [Indexed: 12/04/2022]
Abstract
Genome sequencing data for Streptococcus equi subspecies equi and zooepidemicus were used to develop a novel diagnostic triplex quantitative PCR (qPCR) assay targeting two genes specific to S. equi (eqbE and SEQ2190) and a unique 100 base pair control DNA sequence (SZIC) inserted into the SZO07770 pseudogene of S. zooepidemicus strain H70. This triplex strangles qPCR assay can provide results within 2 h of sample receipt, has an overall sensitivity of 93.9% and specificity of 96.6% relative to the eqbE singlex assay and detects S. equi at levels below the threshold of the culture assay, even in the presence of contaminating bacteria.
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Affiliation(s)
- Katy Webb
- Centre for Preventive Medicine, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, UK
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