Streptococcus spp. are a genus of bacteria that can affect horses, leading to various infections and health conditions. These bacteria are known for causing respiratory and systemic diseases, including strangles, which is primarily caused by Streptococcus equi subsp. equi. Streptococcal infections in horses can result in symptoms such as fever, nasal discharge, and lymph node abscessation. The transmission typically occurs through direct contact with infected animals or contaminated environments. Diagnosis often involves bacterial culture or PCR testing. This page compiles peer-reviewed research studies and scholarly articles that explore the epidemiology, pathogenesis, diagnosis, and treatment of Streptococcus infections in equine populations.
Credille BC, Giguère S, Berghaus LJ, Burton AJ, Sturgill TL, Grover GS, Donecker JM, Brown SA.The objectives of this study were to determine the plasma and pulmonary disposition of ceftiofur crystalline free acid (CCFA) in weanling foals and to compare the plasma pharmacokinetic profile of weanling foals to that of adult horses. A single dose of CCFA was administered intramuscularly to six weanling foals and six adult horses at a dose of 6.6 mg/kg of body weight. Concentrations of desfuroylceftiofur acetamide (DCA) were determined in the plasma of all animals, and in pulmonary epithelial lining fluid (PELF) and bronchoalveolar lavage (BAL) cells of foals. After intramuscular (IM) admin...
Casagrande Proietti P, Bietta A, Coppola G, Felicetti M, Cook RF, Coletti M, Marenzoni ML, Passamonti F.The objective of this manuscript was to validate published PCR-based methods for detection of β-haemolytic Streptococci by comparison with established bacteriological techniques using 85 clinical isolates recovered from uterine swabs of mares with clinical signs of endometritis and to determine the distribution of SeeL/SeeM and SzeL/SzeM superantigens in isolates of Streptococcus equi subsp. equi (S. equi) and S. equi subsp. zooepidemicus (S. zooepidemicus). The conventional bacteriological techniques showed the vast majority of these isolates (78) were S. zooepidemicus with just 5 Streptococ...
Lindahl S, Söderlund R, Frosth S, Pringle J, Båverud V, Aspán A.Strangles is a serious respiratory disease in horses caused by Streptococcus equi subspecies equi (S. equi). Transmission of the disease occurs by direct contact with an infected horse or contaminated equipment. Genetically, S. equi strains are highly homogenous and differentiation of strains has proven difficult. However, the S. equi M-protein SeM contains a variable N-terminal region and has been proposed as a target gene to distinguish between different strains of S. equi and determine the source of an outbreak. In this study, strains of S. equi (n=60) from 32 strangles outbreaks in Sweden ...
Berghaus LJ, Giguère S, Sturgill TL, Bade D, Malinski TJ, Huang R.The objectives of this study were to determine the plasma and pulmonary disposition of gamithromycin in foals and to investigate the in vitro activity of the drug against Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) and Rhodococcus equi. A single dose of gamithromycin (6 mg/kg of body weight) was administered intramuscularly. Concentrations of gamithromycin in plasma, pulmonary epithelial lining fluid (PELF), bronchoalveolar lavage (BAL) cells, and blood neutrophils were determined using HPLC with tandem mass spectrometry detection. The minimum inhibitory concentration of gamithr...
Kuhl J, Winterhoff N, Wulf M, Schweigert FJ, Schwendenwein I, Bruckmaier RM, Aurich JE, Kutzer P, Aurich C.Many foals develop diarrhoea within the first two weeks of life which has been suggested to coincide with postpartum oestrus in their dams. To analyse the pathogenesis of this diarrhoea we have determined faecal bacteria in foals and their dams (n=30 each), and serum IGF-1 and γ-globulins for 6 weeks after birth. In addition, effects of β-carotene supplementation to mares (group 1: 1000 mg/day, n=15, group 2: control, n=15) on diarrhoea in foals were studied. Diarrhoea occurred in 92 and 79% of foals in groups 1 and 2, respectively, but was not correlated with oestrus in mares. Beta-carotene...
McClure S, Sibert G, Hallberg J, Bade D.The efficacy and safety of sustained release ceftiofur administered twice, 4 days apart, for treatment of horses with naturally acquired Streptococcus equi subsp. zooepidemicus (Strep. zoo.) pneumonia was evaluated in a multicenter, placebo-controlled, double-blinded, randomized clinical trial. The study included 373 horses (278 treated and 95 placebos) with naturally acquired pneumonia. Inclusion in the statistical analyses for treatment efficacy for Strep. zoo. required recovery of ≥10(4) CFU/mL of Strep. zoo. on the primary isolation plate which resulted in 201 cases (145 treated and 56 p...
Meyer A, Messer L, De Briel D, Moreau P.The field of zoonoses changes constantly. Streptococcus equi subsp. ruminatorum is a group C Streptococcus subspecies first identified in 2004. The first case of human infection with this agent was reported in 2007. Here, we report a second case. A 70-year-old man had acute spondylodiscitis and endocarditis involving the anterior mitral valve leaflet. S. equi subsp. ruminatorum was identified in the blood cultures. Antibiotic therapy was successful in eradicating the infection. The workup showed hypogammaglobulinemia with stage I myeloma. He reported frequent contacts with horses including tw...
Overbeck W, Witte TS, Heuwieser W.The objective of this study was to compare the accuracy of a uterine swab (US), a cytological brush (CB) and an endometrial biopsy (EB) to detect subclinical endometritis in mares. Cytological and bacteriological results of all three techniques were related to histological occurrence of polymorphonuclear neutrophils (PMNs) in the stratum compactum, commonly known as 'best standard'; to diagnose endometritis. Samples were taken from 55 mares of different breeds without clinical signs of endometritis. Samples for US, CB and EB were collected, smeared on a microscopic slide and cultured for bacte...
Lanka S, Borst LB, Patterson SK, Maddox CW.The objective of the present investigation was to differentiate between strains of Streptococcus equi subspecies equi implicated in abscess formation in vaccinated horses. Streptococcus equi isolates recovered from clinical specimens associated with equine strangles cases submitted to the University of Illinois Veterinary Diagnostic Laboratory were compared with S. equi isolates representing at least 12 lots of a commercial modified live vaccine (MLV) to determine whether the isolates obtained from the abscesses were vaccine or wild type. Genotyping techniques evaluated included enterobacteria...
Urosevic M, Lako B, Milanov D, Urosevic I, Aurich C.Uterine microbiology, antimicrobial susceptibility and endometrial cytology were investigated in a total of 51 mares with fertility problems from 16 different stud farms in Serbia. Uterine cultures were performed after collection with a double guarded uterine swab, and endometrial cytology was evaluated after collection of endometrial cells with a special device (cytology brush). In 21 of 51 mares, at least one bacterial species was isolated from the uterus; the most frequent were Streptococcus equi subsp. zooepidemicus (13 isolates) and E. coli (four isolates). All isolates of Streptococcus e...
Hobo S, Niwa H, Anzai T, Jones JH.In this study, to evaluate the influence of strangles vaccination on serological test results, we investigated the changes in strangles serum antibody levels in horses after vaccination and subsequent intranasal challenge with S. equi. The horses were vaccinated for strangles with either a component vaccine (Group C) or a live vaccine (Group L). We measured changes in strangles serum antibody levels weekly for 20 weeks after vaccinating horses twice for strangles over a 3-week interval, and for 7 weeks after intranasal challenge with S. equi in the same horses. Serum antibody responses to the ...
Ivens PA, Matthews D, Webb K, Newton JR, Steward K, Waller AS, Robinson C, Slater JD.Strangles is the most commonly diagnosed and important infectious disease of horses worldwide. Very little is known about the temporo-spatial and molecular epidemiology of strangles. The disease is not notifiable in the UK and there are few published data on the geographical locations of outbreaks. Objective: To investigate whether typing of a surface protein (SeM) of Streptococcus equi ssp. equi (S. equi), the causative agent of strangles, is a useful epidemiological tool. Methods: The variable region of the SeM gene was amplified from 145 isolates of S. equi by PCR and sequenced. Different S...
BMJ case reportsAugust 26, 2010
Volume 2010 bcr1120092444 doi: 10.1136/bcr.11.2009.2444
Thompson RN, McNicholl BP.This report describes a case of accidental needlestick injury involving a live equine vaccination, Equilis StrepE. A vet presented herself to the Emergency Department having accidentally injected herself with an equine vaccination. Her left thumb (injury site) was inflamed and had lymphangitis progressing proximally along her left arm. Her inflammatory markers were not raised. The swelling, erythma and lymphangitis had improved markedly with intravenous antibiotics. She had no sequelae at follow-up. Equilis StrepE is a vaccine for submucosal administration containing a modified live avirulent ...
Paillot R, Darby AC, Robinson C, Wright NL, Steward KF, Anderson E, Webb K, Holden MT, Efstratiou A, Broughton K, Jolley KA, Priestnall SL....The acquisition of superantigen-encoding genes by Streptococcus pyogenes has been associated with increased morbidity and mortality in humans, and the gain of four superantigens by Streptococcus equi is linked to the evolution of this host-restricted pathogen from an ancestral strain of the opportunistic pathogen Streptococcus equi subsp. zooepidemicus. A recent study determined that the culture supernatants of several S. equi subsp. zooepidemicus strains possessed mitogenic activity but lacked known superantigen-encoding genes. Here, we report the identification and activities of three novel ...
Rajasekhar A, Clancy CJ.Group C streptococci (GCS) are common causes of veterinary diseases and may colonize humans. Human diseases due to GCS are uncommon and generally occur in the elderly and persons exposed to animals or animal products. We report a case of Streptococcus equi subsp. zooepidemicus meningitis in a horse trainer and review 36 cases of GCS meningitis reported in the literature. The median age was 48 y and the majority of patients were previously healthy. Thirty-one percent (11/36) of the reported cases followed equine exposure and 19% (7/36) ingestion of dairy products. Sixty-seven percent (24/36) we...
Poulin MF, Boivin G.Human infections with Streptococcus equi subspecies zooepidemicus, a group C streptococcus, are very rare and are generally associated with contact with horses, and consumption of unpasteurized milk products, goat cheese or pork. In most cases S zooepidemicus leads to fulminant infections. The case of a middle-aged woman who had sporadic contact with horses is described in the present report. She developed a bacteremia with severe and extensive complications that included meningitis, mitral endocarditis and blindness due to bilateral endophthalmitis. To the authors' knowledge, this is the firs...
Minces LR, Brown PJ, Veldkamp PJ.Streptococcus equi subsp. zooepidemicus rarely causes meningitis in humans by contact with domestic animals or their unpasteurized products. In this paper we reviewed the literature pertaining to the epidemiological and clinical aspects relating to this infection on previously reported cases of human disease. Additionally, the case of a 51-year-old female who acquired meningitis with this organism after contact with a horse is described. This patient was successfully treated with ceftriaxone, yet penicillin remains the treatment of choice. This aetiological agent should be considered in the pr...
Witte TS, Bergwerff AA, Scherpenisse P, Drillich M, Heuwieser W.Endometritis is one of the major problems in the horse breeding industry. The use of antibiotics for treatment of endometritis in the mare is recommended as best practice. The intrauterine application of antibiotics, however, has been under discussion over the last years because of concerns about its efficacy. The systemic use of antibiotics has been considered more effective because of its better distribution within the uterus. The objective of the present study was to determine the concentration of ceftiofur derivates in serum and endometrial tissue after intramuscular administration. Specif...
Wada S, Hobo S, Niwa H.To describe the number of cases, etiologies, healing times, and results of microbial culture and susceptibility testing of corneal ulcers in thoroughbred racehorses in Japan. Methods: Retrospective study of the medical records of racehorses belonging to the Japan Racing Association (JRA) from 1997 to 2008. Results: A total of 2846 horses suffered ulcerative keratitis. These horses accounted for 90.5% of all the corneal problems and 54.9% of the entire number of horses with ocular diseases. Running in races was the cause in 64.3% of the cases. The mean healing time of the ulcers developed in ra...
Bailey CS, Macpherson ML, Pozor MA, Troedsson MH, Benson S, Giguere S, Sanchez LC, Leblanc MM, Vickroy TW.The objective was to determine if long-term treatment with trimethoprim sulfamethoxazole (antimicrobial), pentoxifylline (anti-inflammatory/anti-cytokine) and altrenogest (synthetic progestin), would improve pregnancy outcome in mares with experimentally induced placentitis. Seventeen normal, pregnant pony mares were enrolled in the study at 280-295 d of pregnancy. Placentitis was induced in all mares by intra-cervical inoculation of Streptococcus equi subsp. zooepidemicus (10(7) CFU). Five mares served as infected, untreated control animals (Group UNTREAT). Twelve mares (Group TREAT) were inf...
Liu M, Lei B.The secreted Mac protein made by group A Streptococcus (GAS) inhibits opsonophagocytosis of GAS by human polymorphonuclear leukocytes (PMNs). This protein also has the endopeptidase activity against human immunoglobulin G (IgG), and the Cys94, His262 and Asp284 are critical for the enzymatic activity. The horse pathogen Streptococcus equi subspecies equi produces a homologue of Mac (SeMac). SeMac was characterized to determine whether SeMac has IgG endopeptidase activity and inhibits opsonophagocytosis of S. equi by horse PMNs. The gene was cloned and recombinant SeMac was overexpressed in Esc...
Panchaud Y, Gerber V, Rossano A, Perreten V.Bacterial infections present a major challenge in equine medicine. Therapy should be based on bacteriological diagnosis to successfully minimize the increasing number of infections caused by multidrug-resistant bacteria. The present study is a retrospective analysis of bacteriological results from purulent infections in horses admitted at the University Equine Clinic of Bern from 2004 to 2008. From 378 samples analyzed, 557 isolates were identified, of which Staphylococcus aureus, Streptococcus equi subsp. zooepidemicus and coliforms were the most common. Special attention was paid to infectio...
Meehan M, Burke FM, Macken S, Owen P.Streptococcus equi possesses a haem-uptake system homologous to that of Streptococcus pyogenes and Streptococcus zooepidemicus. The system consists of two ligand-binding proteins (Shr and Shp) and proteins (HtsA-C) with homology to an ABC transporter. The haem-uptake system of S. equi differs from that of S. pyogenes and S. zooepidemicus in that Shr is truncated by two-thirds. This study focused on the SeShr, SeShp and SeHtsA proteins of S. equi. Analysis of shr, shp and shphtsA knockout mutants showed that all three proteins were expressed in vitro and that expression was upregulated under co...
Knowles EJ, Mair TS, Butcher N, Waller AS, Wood JL.Thirty horses with no external signs of strangles were tested for exposure to Streptococcus equi subspecies equi (S equi) using a new, commercially available serological test. The horses were also tested for persistent carriage of S equi by endoscopy of the guttural pouches and PCR analysis of lavage samples. The owners were questioned about the recent medical history of the horses. Serology suggested that four horses had been recently exposed to S equi. None of the horses had a known history of strangles but three of the four seropositive horses had recently shown non-specific signs of respir...
Preziuso S, Laus F, Tejeda AR, Valente C, Cuteri V.Streptococcus (S.) dysgalactiae subsp. equisimilis is responsible for severe diseases in humans, including primary bacteraemia, pneumonia, endocarditis, and toxic shock syndrome. Infection in some animal species can also occur, although a few studies have looked into cross-species infectivity. In horses, S. equisimilis is generally considered infrequent or opportunistic, but has recently been isolated from cases of strangles-like disease. Rapid and sensitive diagnostic techniques could enable epidemiological studies and effective investigation of outbreaks involving these bacteria. In this stu...
Paillot R, Robinson C, Steward K, Wright N, Jourdan T, Butcher N, Heather Z, Waller AS.Streptococcus equi is the causative agent of strangles, the most frequently diagnosed infectious disease of horses worldwide. The disease is characterized by abscessation and swelling of the lymph nodes of the head and neck, which can literally strangle the horse to death. S. equi produces four recently acquired phage-associated bacterial superantigens (sAgs; SeeH, SeeI, SeeL, and SeeM) that share homology with the mitogenic toxins of Streptococcus pyogenes. The aim of this study was to characterize the contribution of each of these S. equi sAgs to mitogenic activity in vitro and quantify the ...
Timoney JF, DeNegri R, Sheoran A, Forster N.The clonal Streptococcus equi causes equine strangles, a highly contagious suppurative lymphadenopathy and rhinopharyngitis. An important virulence factor and vaccine component, the antiphagocytic fibrinogen binding SeM of S. equi is a surface anchored fibrillar protein. Two recent studies of N. American, Japanese and European isolates have revealed a high frequency of N-terminal amino acid variation in SeM of S. equi CF32 that suggests this region of the protein is subject to immunologic selection pressure. The aims of the present study were firstly to map regions of SeM reactive with convale...
Jacobi S, Townsend WM, Bolin CA.To evaluate whether equine serum administered via a simulated subpalpebral lavage system (SPL) supports proliferation of Streptococcus zooepidemicus or Pseudomonas aeruginosa within the tubing. Methods: A sterile i.v. catheter with injection cap was inserted into sterilized silicone tubing (Mila). To mimic an SPL within the dorsal conjunctival fornix, the tubing was secured to an elevated platform. The tip of the tubing extended from the platform into a vial containing culture medium just inoculated with approximately 1.5 x 10(8) CFU/mL P. aeruginosa or S. zooepidemicus. To mimic administratio...
Gaede W, Reckling KF, Schliephake A, Missal D, Hotzel H, Sachse K.At a stud farm of Trakehner horses, all 33 foals of a birth cohort developed conjunctivitis and serous to muco-purulent rhinitis, and 7 older horses showed recurrent signs of conjunctivitis. Examination of nasal and conjunctival swabs by bacterial and cell culture, as well as real-time PCR, ArrayTube microarray analysis and DNA sequencing led to the identification of Chlamydophila (C.) caviae (first description in horses) and Streptococcus (S.) equi subsp. zooepidemicus. We presume a synergistic effect associated with these two agents by hypothesising that primary lesions were set by C. caviae...
Boyle AG, Boston RC, O'Shea K, Young S, Rankin SC.Streptococcus equi is the etiologic agent of a highly infectious upper respiratory disease of horses known as strangles. Bacterial culture methods and polymerase chain reaction (PCR) of nasopharyngeal washes and guttural pouch lavages are used routinely to test clinical and carrier animals for the presence of S. equi but no definitive or gold standard test method has been shown to be optimal. We hypothesized that (i) a flocked swab submerged in ten-fold serial dilution suspensions of S. equi prepared in 0.9% NaCl would detect more colony forming units (CFU) than a rayon swab when used to inocu...
Troedsson MH, Liu IK, Ing M, Pascoe J, Thurmond M.The electrical myometrial activity of three mares with a documented increased susceptibility to chronic uterine infection (CUI) and three mares considered to be resistant to CUI was investigated. Electrodes were surgically implanted in the myometrium of the mares and electrical activity was monitored by a Grass polygraph. Oestrus was determined by transrectal ultrasonography of the reproductive tract and teasing of the mares with a stallion. Findings were confirmed by blood progesterone concentrations 35 mm was detected, the uterus was infused with a genital strain of 5 x 10(6) Streptococcus ...
Abdulmawjood A, Lämmler CH.The 16S rRNA gene of 39 S. equi subsp. zooepidemicus strains and two S. equi subsp. equi strains was amplified by polymerase chain reaction and subsequently digested with the restriction enzyme Hinc II. A restriction profile with two fragments with sizes of 1250 bp and 200 bp could be observed for both S. equi subsp. equi strains and for 30 of the 39 S. equi subsp. zooepidemicus strains indicating a sequence variation within the V2 region of the 16S rRNA gene of the remaining nine S. equi subsp. zooepidemicus isolates. A segment of the 16S rRNA gene including the hypervariable V2 region of 11 ...
Meehan M, Burke FM, Macken S, Owen P.Streptococcus equi possesses a haem-uptake system homologous to that of Streptococcus pyogenes and Streptococcus zooepidemicus. The system consists of two ligand-binding proteins (Shr and Shp) and proteins (HtsA-C) with homology to an ABC transporter. The haem-uptake system of S. equi differs from that of S. pyogenes and S. zooepidemicus in that Shr is truncated by two-thirds. This study focused on the SeShr, SeShp and SeHtsA proteins of S. equi. Analysis of shr, shp and shphtsA knockout mutants showed that all three proteins were expressed in vitro and that expression was upregulated under co...
Anzai T, Sheoran AS, Kuwamoto Y, Kondo T, Wada R, Inoue T, Timoney JF.Streptococcus equi causes equine strangles. The acute disease has many of the hallmarks of an acute response including high fever, elevated plasma fibrinogen and neutrophilia, affects known to be mediated by proinflammatory cytokines. The objective of this study was to screen-culture supernatants from equine clinical isolates of S. equi and S. zooepidemicus for stimulation of mitogenic responses by horse peripheral blood mononuclear cells. Mitogenicity comparable to that of concanavalin A was detected in culture supernatants of S. equi strains but not in those of S. zooepidemicus. Mitogenicity...
Timoney JF, Yang J, Liu J, Merant C.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 ...
Lakritz J, Wilson WD, Berry CR, Schrenzel MD, Carlson GP, Madigan JE.Twenty-three foals, between 1 and 7 months old, with signs of acute respiratory distress, were examined at the Veterinary Medical Teaching Hospital (VMTH), University of California, Davis, between 1984 and 1989. Characteristic features included sudden onset of severe respiratory distress and tachypnea, cyanosis unresponsive to nasal oxygen, pyrexia, hypoxemia, hypercapneic respiratory acidosis, poor response to treatment, and histopathologic lesions of bronchiolitis and bronchointerstitial pneumonia. Seven of the 23 foals were normal before the onset of respiratory distress, 3 foals were found...
Carr EA, Carlson GP, Wilson WD, Read DH.To characterize history, clinical signs, and pathologic findings in horses with histologically confirmed acute hemorrhagic pulmonary infarction and necrotizing pneumonia. Methods: Retrospective study. Methods: 21 horses. Results: 19 of the 21 horses were Thoroughbred racehorses in training. Eighteen horses had had strenuous exercise immediately prior to onset of illness. Fifteen horses had a serosanguineous nasal discharge during hospitalization. Seventeen horses had radiographic evidence of pulmonary consolidation and pleural effusion. Nine of 14 horses had ultrasonographic evidence of large ...
Waller AS, Robinson C.The host-restricted bacterium Streptococcus equi is the causative agent of equine strangles, the most frequently diagnosed infectious disease of horses worldwide. The disease is characterized by abscessation of the lymph nodes of the head and neck, leading to significant welfare and economic cost. S. equi is believed to have evolved from an ancestral strain of Streptococcus zooepidemicus, an opportunistic pathogen of horses and other animals. Comparison of the genome of S. equi strain 4047 with those of S. zooepidemicus identified examples of gene loss due to mutation and deletion, and gene ga...
Yildirim AO, Lämmler Ch, Weiss R.Seven group B streptococcal cultures isolated from three horses reacted with group B-specific antiserum, were CAMP positive, pigmented and showed the typical biochemical properties of Streptococcus agalactiae. The identification could be confirmed by PCR amplification of the 16S rRNA gene and a subsequent RsaI restriction pattern typical for S. agalactiae. In addition, the isolates were identified by amplification of species specific parts of the 16S rRNA gene, the 16S-23S rRNA intergenic spacer region and by amplification of the CAMP-factor (cfb) gene. Six isolates could be classified as sero...
Boyle AG.Strangles, caused by the bacteria Streptococcus equi subsp equi, is a highly contagious disease of equids classically characterized by a high fever and enlarged lymph nodes of the head. Diagnostic sampling depends on the stage of the disease. The goal of treating strangles is to control transmission and to eliminate infection while providing future host immunity. Daily temperature checking and isolation of febrile horses is the key to controlling outbreaks. Eradication of this disease will not be possible until S equi carriers are eliminated from the equine population.
Chhabra D, Bhatia T, Goutam U, Manuja A, Kumar B.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 i...
Mair TS.Three horses developed severe pulmonary infections while being treated with systemic corticosteroids for other diseases. Two of them had an immune-mediated skin disease, compatible with a diagnosis of pemphigus foliaceus, and one had severe chronic obstructive pulmonary disease. Case 1 developed diffuse pneumonia from which Streptococcus zooepidemicus and Bacteroides melaninogenicus were isolated, and it responded to antibiotic therapy. Case 2 developed septicaemia, pulmonary thrombosis and pneumonia associated with Escherichia coli, and died during a peracute illness with signs of disseminate...
Prescott JF, Srivastava SK, deGannes R, Barnum DA.A mild form of strangles caused by an atypical Streptococcus equi was recognized on a large horse breeding farm. The organism differed from most S equi isolates by disappearance of the mucoid capsule by 24 hours of culture, leaving a matt-type colony. Typically, the clinical signs were a transient (24-48 hour) fever, profuse nasal discharge, and anorexia. In about half the affected animals, there was moderate mandibular lymph node enlargement, and these glands usually ruptured or were drained. The use of a passive hemagglutination antibody test showed that subclinical infection was widespread ...
Burrell MH, Mackintosh ME, Taylor CE.Streptococcus pneumoniae was isolated from nasopharyngeal swabs and tracheal washings taken from Thoroughbred horses in training at three of four separate stables that were sampled during investigations into respiratory disease. The growth of Strep pneumoniae in culture was enhanced by an environment enriched with carbon dioxide. In one stable, five of 15 horses that were sampled repeatedly were found to carry the organism for at least four months. There was an apparent association between lower respiratory tract inflammatory disease and heavy growths (10(6) to 10(8) colony forming units/ml) p...
Waller A., head of bacteriology at the AHT, describes the causative agent of strangles in horses, and discusses progress with the latest research aimed at improving vaccines against this global disease.
McClure SR, Koenig R, Hawkins PA.To evaluate the effectiveness of a novel trimethoprim-sulfadiazine oral suspension for the treatment of naturally acquired Streptococcus equi subsp zooepidemicus infection in horses. Methods: Randomized, controlled field trial. Methods: 180 horses with S equi subsp zooepidemicus infection. Methods: Horses with lower respiratory tract infections caused by S equi subsp zooepidemicus were treated with a new formulation of combined trimethoprim-sulfadiazine oral suspension at a dosage of 24 mg/kg (10.9 mg/lb) twice daily for 10 days (treatment group) or with an equivalent volume of saline (0.9% Na...
Boyle AG, Rankin SC, O'Shea K, Stefanovski D, Peng J, Song J, Bau HH.Rapid point-of-care (POC) detection of Streptococcus equi subsp. equi (S. equi) would theoretically reduce the spread of strangles by identifying index and carrier horses. Objective: That the eqbE isothermal amplification (LAMP) assay, and the same eqbE LAMP assay tested in a microfluidic device format, are comparable to a triplex real-time quantitative polymerase chain reaction (qPCR) assay that is commonly used in diagnostic labs. Methods: Sixty-eight guttural pouch lavage (GPL) specimens from horses recovering from strangles. Methods: Guttural pouch lavage specimens were tested for S. equi ...
Witte TS, Bergwerff AA, Scherpenisse P, Drillich M, Heuwieser W.Endometritis is one of the major problems in the horse breeding industry. The use of antibiotics for treatment of endometritis in the mare is recommended as best practice. The intrauterine application of antibiotics, however, has been under discussion over the last years because of concerns about its efficacy. The systemic use of antibiotics has been considered more effective because of its better distribution within the uterus. The objective of the present study was to determine the concentration of ceftiofur derivates in serum and endometrial tissue after intramuscular administration. Specif...
Boyle AG, Mitchell C, Stefanovski D, Waller AS.The dual antigen iELISA uses two Streptococcus equi subsp equi surface protein antigens composed of N-terminal portions of SEQ2190 (Antigen A) and SeM (Antigen C). It is currently used to identify animals exposed to S. equi which have developed an immune response to the target antigens. Objective: To determine the usefulness of the dual antigen iELISA in a population of horses vaccinated with Pinnacle IN. We hypothesised that horses vaccinated for strangles with a live attenuated, non-encapsulated SeM-2 strain of S. equi, would seroconvert when tested 5 weeks later by the dual antigen iELIS...
Casagrande Proietti P, Bietta A, Coppola G, Felicetti M, Cook RF, Coletti M, Marenzoni ML, Passamonti F.The objective of this manuscript was to validate published PCR-based methods for detection of β-haemolytic Streptococci by comparison with established bacteriological techniques using 85 clinical isolates recovered from uterine swabs of mares with clinical signs of endometritis and to determine the distribution of SeeL/SeeM and SzeL/SzeM superantigens in isolates of Streptococcus equi subsp. equi (S. equi) and S. equi subsp. zooepidemicus (S. zooepidemicus). The conventional bacteriological techniques showed the vast majority of these isolates (78) were S. zooepidemicus with just 5 Streptococ...
Chapuis RJJ, Smith JS, Uehlinger FD, Meachem M, Johnson R, Dowling PM.The objectives of this study were to investigate the pharmacokinetics (PK), pharmacodynamics (PD), and the efficacy of oral administration of doxycycline (DXC) in horses with Streptococcus zooepidemicus tissue infections. Tissue chambers (TC) were implanted subcutaneously in the cervical region of 7 horses and inoculated with a single S. zooepidemicus isolate with a minimum inhibitory concentration (MIC) of 0.25 µg/ml, determined by agar dilution. Doxycycline hyclate (10 mg/kg, orally, q 12 h, for 5 days) mixed with poloxamer gel was started following inoculation. The TC fluid was samp...
Troedsson MH, deMoraes MJ, Liu IK.The relationship between histologic lesions in endometrial biopsy specimens and susceptibility to chronic uterine infection (CUI) in mares was investigated. Mares were allotted to 4 groups on the basis of degree of endometrial lesions. Mares in group 1 (n = 6) had no pathologic changes, mares in group 2 (n = 5) had only mild pathologic changes, group-3 mares (n = 7) had moderate changes, and group-4 mares (n = 7) had severe inflammatory and fibrotic endometrial changes. Susceptibility to CUI was determined by the inflammatory response to intrauterine inoculation of 5 x 10(6) Streptococcus zooe...
Quist EM, Dougherty JJ, Chaffin MK, Porter BF.A 1.5-year-old Quarter Horse gelding with a history of chronic nasal discharge and leukocytosis presented with signs of increased lethargy and muscular pain. The horse quickly became recumbent and unable to rise and was euthanized due to a poor prognosis. At necropsy, severe bilateral guttural pouch empyema was observed, as well as numerous well-demarcated areas of pallor within the skeletal muscles of all major muscle groups. Polymerase chain reaction testing of the guttural pouch exudate confirmed an infection with Streptococcus equi subsp. equi, and an S. equi-associated immune-mediated rha...
Lo Giudice R, Rizzo G, Centofanti A, Favaloro A, Rizzo D, Cervino G, Squeri R, Costa BG, La Fauci V, Lo Giudice G.The use of equine bone blocks is widely reported for bone augmentation techniques. The block must be shaped according to the form of the defect that should be regenerated. The shaping could be performed by hand before or during the surgery, in a sterile ambient, or using a CNC milling machine that could not be sterile. The aim of our study was to evaluate if a steam sterilization could provide a medical grade sterilization of the blocks and to evaluate if bone microstructure and collagen structures change after different steam sterilization protocols provided by mainstream autoclave. Methods: ...
Dart AJ, Hutchins DR, Begg AP.A 12-year-old Thoroughbred mare, with a history of anorexia, dramatic weight loss, fluctuating pyrexia and intermittent diarrhoea after an episode of colic, was presented for examination with depression, emaciation and ataxia. Thoracic and abdominal paracenteses yielded copious quantities of inflammatory exudate. Palpation per rectum revealed an enlarged spleen. The primary alterations in haematology included a severe leucocytosis with a left shift, and a hyperproteinaemia characterised by hypoalbuminaemia and hypergammaglobulinaemia. Post-mortem examination revealed a low grade pleurisy and p...
Scofield D, Black J, Wittenburg L, Gustafson D, Ferris R, Hatzel J, Traub-Dargatz J, McCue P.Systemic administration of ceftiofur crystalline free acid (CCFA) may be a potential treatment for infectious endometritis caused by Streptococcus equi ssp. zooepidemicus (S. zooepidemicus) and other susceptible bacterial organisms in the mare. Objective: To determine if i.m. administration of CCFA at the label dose will exceed the minimum inhibitory concentration (MIC) of S. zooepidemicus in the endometrium following single administration and multiple administration protocols. Methods: Experimental pharmacokinetic study. Methods: Three mares (Group 1) were administered a single i.m. dos...
Bousquet-Mélou A, Schneider M, El Garch F, Broussou DC, Ferran AA, Lallemand EA, Triboulloy C, Damborg P, Toutain PL.Marbofloxacin (MBX), a fluoroquinolone (FQ), is considered as a critical antibiotic requiring antimicrobial susceptibility testing (AST) for prudent use. No clinical breakpoint (CBP) currently exists to interpret the results of such tests in horses. Objective: To compute PK/PD cut-offs (PK/PDCO ) that is one of the three minimum inhibitory concentrations (MICs) considered establishing a CBP for antimicrobial susceptibility test interpretation. Methods: A meta-analysis conducted by combining five sets of previously published pharmacokinetic data, obtained in clinical and nonclinical settings. M...
Causey RC, Artiushin SC, Crowley IF, Weber JA, Homola AD, Kelley A, Stephenson LA, Opitz HM, Guilmain S, Timoney JF.Attenuated Salmonella enterica serovar Typhimurium MGN707, expressing the SzP protective protein of the MB9 serovar of Streptococcus equi subspecies zooepidemicus (SzP-MB9) was tested for its safety and efficacy as a nebulised intranasal vaccine against streptococcal uterine infections in mares. In a preliminary study, vaccinated mares (n=5) displayed serum, nasal and uterine responses (P<0.05) to S. Typhimurium lipopolysaccharide (St-LPS). Subsequently, vaccinated mares (expressor group, n=7), but not mares vaccinated with the vector only (control group, n=7), displayed significant increas...
