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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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2
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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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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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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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5
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Velineni S, Timoney JF. Evidence for involvement of the Fas BCAX regulon in capsule synthesis by Streptococcus equi. Vet Microbiol 2018; 219:113-116. [PMID: 29778182 DOI: 10.1016/j.vetmic.2018.04.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 04/09/2018] [Accepted: 04/10/2018] [Indexed: 11/17/2022]
Abstract
The constitutively expressed hyaluronic acid capsule is an important virulence factor of Streptococcus equi, the cause of equine strangles. Study of the genomic sequence of CF22caps-, a non-encapsulated mutant of S. equi CF22 generated by gamma (Co60) irradiation revealed a non-sense mutation in fasC (SEQ_0302), a sensor kinase gene in FasBCAX an operon with an important regulatory role in expression of streptococcal secreted virulence and matrix binding proteins. The mutation was associated with a significant (p < .05) decrease in transcription of hasA, the synthase gene essential for hyaluronic acid synthesis and, conversely, with small increases in transcription of skc, covR and seM. The early growth phase of CF22caps- was also delayed compared to the CF22caps+ parent. In contrast to the human pathogen, S. pyogenes, capsule synthesis in S. equi therefore appears to be controlled by FasBCAX and not by CovRS.
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Affiliation(s)
- Sridhar Velineni
- Gluck Equine Research Center, University of Kentucky, Lexington, KY, 40546, USA
| | - John F Timoney
- Gluck Equine Research Center, University of Kentucky, Lexington, KY, 40546, USA.
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Velineni S, Sheoran AS, Breathnach CC, Rash NL, Paillot R, Timoney JF. Mitogenic Equine Isolates of Streptococcus zooepidemicus From North America Host Superantigen Genes Similar to Those Hosted in Europe. J Equine Vet Sci 2017. [DOI: 10.1016/j.jevs.2016.09.003] [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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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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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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TIMONEY JF, SUTHER P, VELINENI S, ARTIUSHIN SC. The Antiphagocytic Activity of SeM of Streptococcus equi Requires Capsule. J Equine Sci 2014; 25:53-6. [PMID: 25013359 PMCID: PMC4090359 DOI: 10.1294/jes.25.53] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 04/08/2014] [Indexed: 11/01/2022] Open
Abstract
Resistance to phagocytosis is a crucial virulence property of Streptococcus equi (Streptococcus equi subsp. equi; Se), the cause of equine strangles. The contribution and interdependence of capsule and SeM to killing in equine blood and neutrophils were investigated in naturally occurring strains of Se. Strains CF32, SF463 were capsule and SeM positive, strains Lex90, Lex93 were capsule negative and SeM positive and strains Se19, Se1-8 were capsule positive and SeM deficient. Phagocytosis and killing of Se19, Se1-8, Lex90 and Lex93 in equine blood and by neutrophils suspended in serum were significantly (P ≤ 0.02) greater compared to CF32 and SF463. The results indicate capsule and SeM are both required for resistance to phagocytosis and killing and that the anti-phagocytic property of SeM is greatly reduced in the absence of capsule.
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Affiliation(s)
- John F. TIMONEY
- Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY
40546-0099, USA
| | - Pranav SUTHER
- Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY
40546-0099, USA
| | - Sridhar VELINENI
- Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY
40546-0099, USA
| | - Sergey C. ARTIUSHIN
- Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY
40546-0099, USA
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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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11
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Potempa M, Potempa J. Protease-dependent mechanisms of complement evasion by bacterial pathogens. Biol Chem 2013; 393:873-88. [PMID: 22944688 DOI: 10.1515/hsz-2012-0174] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Accepted: 05/06/2012] [Indexed: 12/11/2022]
Abstract
The human immune system has evolved a variety of mechanisms for the primary task of neutralizing and eliminating microbial intruders. As the first line of defense, the complement system is responsible for rapid recognition and opsonization of bacteria, presentation to phagocytes and bacterial cell killing by direct lysis. All successful human pathogens have mechanisms of circumventing the antibacterial activity of the complement system and escaping this stage of the immune response. One of the ways in which pathogens achieve this is the deployment of proteases. Based on the increasing number of recent publications in this area, it appears that proteolytic inactivation of the antibacterial activities of the complement system is a common strategy of avoiding targeting by this arm of host innate immune defense. In this review, we focus on those bacteria that deploy proteases capable of degrading complement system components into non-functional fragments, thus impairing complement-dependent antibacterial activity and facilitating pathogen survival inside the host.
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Affiliation(s)
- Michal Potempa
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland.
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12
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Artiushin S, Tong Y, Timoney J, Lemieux B, Schlegel A, Kong H. Thermophilic helicase-dependent DNA amplification using the IsoAmp™ SE experimental kit for rapid detection of Streptococcus equi subspecies equi in clinical samples. J Vet Diagn Invest 2012; 23:909-14. [PMID: 21908346 DOI: 10.1177/1040638711416968] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
A simple and portable assay for detection of Streptococcus equi subspecies equi has been developed based on amplification of S. equi-specific sequence using a thermophilic helicase-dependent reaction followed by visual detection of the amplicon in a disposable lateral flow cassette. An experimental kit (IsoAmp™ SE) was evaluated. Analytical sensitivity was 50 copies of S. equi genomic DNA per reaction. The IsoAmp SE assay had 100% specificity when applied to nasal swabs and washes. The assay was more sensitive than culture but less sensitive than nested polymerase chain reaction (PCR). The test requires neither expensive equipment nor extensive training of personnel, provides a practical alternative to culture or PCR assays for detection of S. equi in clinical samples, and expedites identification of atypical colonies of S. equi and Streptococcus zooepidemicus in the laboratory.
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Affiliation(s)
- Sergey Artiushin
- 1Sergey Artiushin, Gluck Equine Research Center, University of Kentucky, Lexington, KY 40546, USA.
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Ma Z, Zhang H, Zheng J, Li Y, Yi L, Fan H, Lu C. Interaction between M-like protein and macrophage thioredoxin facilitates antiphagocytosis for Streptococcus equi ssp. zooepidemicus. PLoS One 2012; 7:e32099. [PMID: 22384152 PMCID: PMC3288065 DOI: 10.1371/journal.pone.0032099] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Accepted: 01/19/2012] [Indexed: 11/19/2022] Open
Abstract
Streptococcus equi ssp. zooepidemicus (S. zooepidemicus, S.z) is one of the common pathogens that can cause septicemia, meningitis, and mammitis in domesticated species. M-like protein (SzP) is an important virulence factor of S. zooepidemicus and contributes to bacterial infection and antiphagocytosis. The interaction between SzP of S. zooepidemicus and porcine thioredoxin (TRX) was identified by the yeast two-hybrid and further confirmed by co-immunoprecipitation. SzP interacted with both reduced and the oxidized forms of TRX without inhibiting TRX activity. Membrane anchored SzP was able to recruit TRX to the surface, which would facilitate the antiphagocytosis of the bacteria. Further experiments revealed that TRX regulated the alternative complement pathway by inhibiting C3 convertase activity and associating with factor H (FH). TRX alone inhibited C3 cleavage and C3a production, and the inhibitory effect was additive when FH was also present. TRX inhibited C3 deposition on the bacterial surface when it was recruited by SzP. These new findings indicated that S. zooepidemicus used SzP to recruit TRX and regulated the alternative complement pathways to evade the host immune phagocytosis.
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Affiliation(s)
| | | | | | | | | | - Hongjie Fan
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- * E-mail:
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Waller AS, Paillot R, Timoney JF. Streptococcus equi: a pathogen restricted to one host. J Med Microbiol 2011; 60:1231-1240. [DOI: 10.1099/jmm.0.028233-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Affiliation(s)
- Andrew S. Waller
- Centre for Preventive Medicine, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, UK
| | - Romain Paillot
- Centre for Preventive Medicine, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, UK
| | - John F. Timoney
- Gluck Equine Research Center, University of Kentucky, Lexington, KY 40546, USA
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Ijaz M, Velineni S, Timoney JF. Selective pressure for allelic diversity in SeM of Streptococcus equi does not affect immunoreactive proteins SzPSe or Se18.9. INFECTION GENETICS AND EVOLUTION 2011; 11:1159-63. [PMID: 21256981 DOI: 10.1016/j.meegid.2011.01.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Revised: 12/22/2010] [Accepted: 01/16/2011] [Indexed: 01/25/2023]
Abstract
Streptococcus equi, a clone or biovar of an ancestral Streptococcus zooepidemicus of Lancefield group C causes equine strangles, a highly contagious tonsillitis and lymphadenitis of the head and neck. At least 74 alleles based on N-terminal amino acid sequence of the anti-phagocytic SeM have been observed among isolates of S. equi from N. America, Europe and Japan. A d(N)/d(S) ratio of 5.93 for the 5' region of sem is indicative of positive selective pressure. The aim of this study was to determine whether variations in SeM were accompanied by variations in the surface exposed SzPSe and secreted Se18.9, both of which bind to equine tonsillar epithelium and, along with SeM, elicit strong nasopharyngeal IgA responses during convalescence. Sequences of genes for these proteins from 25 S. equi expressing 19 different SeM alleles isolated over 40 years in different countries were compared. No variation was observed in szpse, except for an Australian isolate with a deletion of a single repeat in the 3' end of the gene. Interestingly, only two SNP loci were detected in se18.9 compared to 93 and 55 in sem and szpse, respectively. The high frequency of nucleotide substitutions in szpse may be related to its mosaic structure since this gene in S. zooepidemicus exists in a variety of combinations of sequence segments and has a central hypervariable region that includes exogenous DNA sequence based on an atypical G-C percentage. In summary, the results of this study document very different responses of streptococcal genes for 3 immunoreactive proteins to selection pressure of the nasopharyngeal mucosal immune response.
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Affiliation(s)
- Muhammad Ijaz
- Maxwell H Gluck Equine Research Center, University of Kentucky, Lexington, KY 40546-0099, United States
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Byun JW, Yoon SS, Woo GH, Jung BY, Joo YS. An outbreak of fatal hemorrhagic pneumonia caused by Streptococcus equi subsp. zooepidemicus in shelter dogs. J Vet Sci 2009; 10:269-71. [PMID: 19687630 PMCID: PMC2801124 DOI: 10.4142/jvs.2009.10.3.269] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
An outbreak of fatal hemorrhagic pneumonia with 70~90% morbidity and 50% mortality occurred in an animal shelter in Yangju, Gyeonggi Province, Korea. Clinically, the affected dogs showed severe respiratory distress within 48 h after arriving in the shelter. The dead were found mainly with nasal bleeding and hematemesis. At necropsy, hemothorax and hemorrhagic pneumonia along with severe pulmonary consolidation was observed, though histopathological analysis showed mainly hemorrhagic bronchopneumonia. Lymphoid depletion was inconsistently seen in the spleen, tonsil and bronchial lymph node. Gram-positive colonies were shown in blood vessels or parenchyma of cerebrum, lung, liver, spleen, and kidney. Also, Streptococcus (S.) equi subsp. zooepidemicus was isolated from the various organs in which the bacterium was microscopically and histologically detected. In addition, approximately 0.9 Kb specific amplicon, antiphagocytic factor H binding protein, was amplified in the bacterial isolates. In this study, we reported an outbreak of canine hemorrhagic bronchopneumonia caused by S. equi subsp. zooepidemicus in an animal shelter in Yangju, Korea.
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Affiliation(s)
- Jae Won Byun
- Animal Disease Diagnostic Center, National Veterinary Research and Quarantine Service, Anyang 430-824, Korea.
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17
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Holden MTG, Heather Z, Paillot R, Steward KF, Webb K, Ainslie F, Jourdan T, Bason NC, Holroyd NE, Mungall K, Quail MA, Sanders M, Simmonds M, Willey D, Brooks K, Aanensen DM, Spratt BG, Jolley KA, Maiden MCJ, Kehoe M, Chanter N, Bentley SD, Robinson C, Maskell DJ, Parkhill J, Waller AS. Genomic evidence for the evolution of Streptococcus equi: host restriction, increased virulence, and genetic exchange with human pathogens. PLoS Pathog 2009; 5:e1000346. [PMID: 19325880 PMCID: PMC2654543 DOI: 10.1371/journal.ppat.1000346] [Citation(s) in RCA: 171] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2008] [Accepted: 02/24/2009] [Indexed: 11/19/2022] Open
Abstract
The continued evolution of bacterial pathogens has major implications for both human and animal disease, but the exchange of genetic material between host-restricted pathogens is rarely considered. Streptococcus equi subspecies equi (S. equi) is a host-restricted pathogen of horses that has evolved from the zoonotic pathogen Streptococcus equi subspecies zooepidemicus (S. zooepidemicus). These pathogens share approximately 80% genome sequence identity with the important human pathogen Streptococcus pyogenes. We sequenced and compared the genomes of S. equi 4047 and S. zooepidemicus H70 and screened S. equi and S. zooepidemicus strains from around the world to uncover evidence of the genetic events that have shaped the evolution of the S. equi genome and led to its emergence as a host-restricted pathogen. Our analysis provides evidence of functional loss due to mutation and deletion, coupled with pathogenic specialization through the acquisition of bacteriophage encoding a phospholipase A2 toxin, and four superantigens, and an integrative conjugative element carrying a novel iron acquisition system with similarity to the high pathogenicity island of Yersinia pestis. We also highlight that S. equi, S. zooepidemicus, and S. pyogenes share a common phage pool that enhances cross-species pathogen evolution. We conclude that the complex interplay of functional loss, pathogenic specialization, and genetic exchange between S. equi, S. zooepidemicus, and S. pyogenes continues to influence the evolution of these important streptococci. Streptococci colonize a diverse range of animals and tissues, and this association is normally harmless. Occasionally some strains of streptococci have an increased ability to cause disease that is often associated with a reduction in the ability to colonize and the acquisition of new genes, which enable the strain to inhabit a new niche. S. equi is the causative agent of strangles, one of the most frequently diagnosed and feared infectious diseases of horses, which is believed to have evolved from the closely related and usually harmless S. zooepidemicus. We aim to understand the mechanisms by which S. equi causes disease by studying and comparing the genomes of these different strains. Here we identify specific genes that have been lost and gained by S. equi, which may have directed its transition from colonizer to invader. Several of the novel genes acquired by S. equi have also been identified in strains of the closely related bacterium S. pyogenes that are associated with increased morbidity and mortality in humans. Our research highlights the role of genetic exchange in cross-species bacterial evolution and argues that the evolution of human pathogens cannot be considered in isolation.
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Affiliation(s)
- Matthew T. G. Holden
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Zoe Heather
- Centre for Preventive Medicine, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, United Kingdom
| | - Romain Paillot
- Centre for Preventive Medicine, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, United Kingdom
| | - Karen F. Steward
- Centre for Preventive Medicine, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, United Kingdom
| | - Katy Webb
- Centre for Preventive Medicine, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, United Kingdom
| | - Fern Ainslie
- Centre for Preventive Medicine, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, United Kingdom
| | - Thibaud Jourdan
- Centre for Preventive Medicine, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, United Kingdom
| | - Nathalie C. Bason
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Nancy E. Holroyd
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Karen Mungall
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Michael A. Quail
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Mandy Sanders
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Mark Simmonds
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - David Willey
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Karen Brooks
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - David M. Aanensen
- Department of Infectious Disease Epidemiology, Imperial College London, St. Mary's Hospital Campus, London, United Kingdom
| | - Brian G. Spratt
- Department of Infectious Disease Epidemiology, Imperial College London, St. Mary's Hospital Campus, London, United Kingdom
| | - Keith A. Jolley
- The Peter Medawar Building for Pathogen Research and Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Martin C. J. Maiden
- The Peter Medawar Building for Pathogen Research and Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Michael Kehoe
- Institute for Cell and Molecular Biosciences, The Medical School, University of Newcastle upon Tyne, Newcastle upon Tyne, United Kingdom
| | - Neil Chanter
- Centre for Preventive Medicine, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, United Kingdom
| | - Stephen D. Bentley
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Carl Robinson
- Centre for Preventive Medicine, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, United Kingdom
| | - Duncan J. Maskell
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Julian Parkhill
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Andrew S. Waller
- Centre for Preventive Medicine, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, United Kingdom
- * E-mail:
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18
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Abstract
REASONS FOR PERFORMING STUDY Little is known about entry and subsequent multiplication of Streptococcus equi following exposure of a susceptible horse. This information would have value in design of intranasal vaccines and understanding of shedding and protective immune responses. OBJECTIVES To determine entry points and sites of subsequent replication and dispersion of S. equi at different times after intranasal infection or commingling exposure. METHODS Previously unexposed horses and ponies were subjected to euthanasia 1, 3, 20 or 48 h following intranasal inoculation with biotin labelled or unlabelled S. equi CF32. Some ponies were inoculated with suspensions of equal numbers of CF32 and its mutants lacking capsule, S. equi M-like protein or streptolysin S. Others were infected by commingling exposure and subjected to euthanasia after onset of fever. Tonsils and lymph nodes were cultured for S. equi and tissues sectioned for histopathological examination and fluorescent microscopy. RESULTS Tonsillar tissues of both the oro- and nasopharynx served as portals of entry. Entry was unexpectedly rapid but involved few bacteria. Small numbers of organisms were detected in tonsillar crypts, in adjacent subepithelial follicular tissue and draining lymph nodes 3 h after inoculation. By 48 h, clumps of S. equi were visible in the lamina propria. At onset of fever, tonsillar tissues and one or more mandibular and retropharyngeal lymph nodes were heavily infiltrated by neutrophils and long chains of extracellular S. equi. Mutant S. equi lacking virulence factors were not seen in draining lymph nodes. CONCLUSIONS Although very small numbers of S. equi entered the lingual and nasopharyngeal tonsils, carriage to regional lymph nodes occurred within hours of inoculation. This observation, together with visual evidence of intracellular and extracellular multiplication of S. equi in tonsillar lymphoid tissue and lymph nodes over the following days, indicates involvement of potent antiphagocytic activity and failure of innate immune defences. RELEVANCE Future research should logically address the tonsillar immune mechanisms involved including identification of effector cell(s) and antigens.
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Affiliation(s)
- J F Timoney
- Gluck Equine Research Center, University of Kentucky, Lexington, Kentucky 40546-0099, USA
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19
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Pesavento PA, Hurley KF, Bannasch MJ, Artiushin S, Timoney JF. A Clonal Outbreak of Acute Fatal Hemorrhagic Pneumonia in Intensively Housed (Shelter) Dogs Caused by Streptococcus equi subsp. zooepidemicus. Vet Pathol 2008; 45:51-3. [DOI: 10.1354/vp.45-1-51] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
An outbreak of acute, fatal, hemorrhagic pneumonia was observed in more than 1,000 mixed breed dogs in a single animal shelter. The Department of Anatomic Pathology at the University of California at Davis School of Veterinary Medicine performed necropsies on dogs that were found moribund in acute respiratory distress or found dead with evidence of nasal bleeding. All dogs had hemothorax and an acute, fibrinosuppurative pneumonia. Large numbers of gram-positive cocci were observed within the lungs of all dogs and within septic thromboemboli of remote organs in about 50% of cases. Bacterial cultures from the dogs and their environment revealed widespread beta-hemolytic Streptococus equi subspecies zooepidemicus (Lancefield Group C). Extensive diagnostic testing failed to reveal the consistent presence of copathogens in individual cases. The clinical, epidemiologic, molecular biologic, and pathologic data indicate that a single clone of S. zooepidemicus was the cause of an acutely fatal respiratory infection in these dogs.
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Affiliation(s)
- P. A. Pesavento
- School of Veterinary Medicine, Department of Pathology, Microbiology, and Immunology, University of California at Davis, Davis, CA
| | - K. F. Hurley
- Koret Shelter Medicine Program, University of California at Davis, Davis, CA
| | - M. J. Bannasch
- Koret Shelter Medicine Program, University of California at Davis, Davis, CA
| | - S. Artiushin
- Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY
| | - J. F. Timoney
- Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY
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20
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Timoney JF, Yang J, Liu J, Merant C. IdeE reduces the bactericidal activity of equine neutrophils for Streptococcus equi. Vet Immunol Immunopathol 2007; 122:76-82. [PMID: 18077002 DOI: 10.1016/j.vetimm.2007.10.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2007] [Revised: 09/28/2007] [Accepted: 10/31/2007] [Indexed: 11/18/2022]
Abstract
Streptococcus equi (S. equi) causes equine strangles, a highly contagious and widespread purulent lymphadenitis of the head and neck. Highly resistant to phagocytosis, it produces long extracellular chains in affected lymph nodes. In a screen of clones reactive with convalescent serum from a gene library of S. equi CF32 we identified IdeE, an IgG-endopeptidase and homologue of the leucocyte receptor Mac-1 (CD11b). IdeE is expressed during S. equi infection eliciting both serum and mucosal antibody responses which persisted at significant levels in serum for over 200 days. Release from S. equi into culture medium was detected during the exponential phase of growth. The closely related Streptococcus zooepidemicus appeared to store the protein but not to release it. Antiphagocytic activity for equine neutrophils was dose-dependent and neutralized by IdeE-specific antiserum. Biotinylated IdeE bound weakly to about 77% of purified equine neutrophils and strongly to the remainder.
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Affiliation(s)
- John F Timoney
- Department of Veterinary Science, University of Kentucky, Lexington, KY 40546-0099, USA.
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21
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Timoney JF, Qin A, Muthupalani S, Artiushin S. Vaccine potential of novel surface exposed and secreted proteins of Streptococcus equi. Vaccine 2007; 25:5583-90. [PMID: 17360081 DOI: 10.1016/j.vaccine.2007.02.040] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2006] [Revised: 01/09/2007] [Accepted: 02/07/2007] [Indexed: 11/18/2022]
Abstract
Streptococcus equi, a clonal descendent of an ancestral S. zooepidemicus, causes equine strangles, a highly contagious purulent lymphadenitis of the head and neck. The aim of this study was to evaluate as vaccine components novel surface exposed or secreted S. equi proteins identified in an expression gene library with sera from resistant horses. Six proteins expressed by S. equi CF32 but not by S. zooepidemicus 631 were used to vaccinate one group of eight ponies. A second pony group was immunized with five adhesin and other proteins encoded by genes of Linkage Gr 1. All ponies made strong serum antibody responses to each protein as measured by ELISA but none were resistant to subsequent comingling challenge with S. equi CF32. These results in combination with evidence that recovered horses rapidly clear intranasally inoculated S. equi and do not make detectable serum antibody responses to its surface proteins suggest that acquired immune-mediated tonsillar clearance and not serum antibody must be stimulated by an effective strangles vaccine.
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Affiliation(s)
- John F Timoney
- Gluck Equine Research Center, University of Kentucky, Lexington, KY 40546, United States.
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