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.
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...
Romanowska D, Szynkiewicz Z, Rita J.Antistreptolysin O (ASO) titers were determined in the sera of 532 horses from stud farms and 436 working horses from small farms. A statistically significant correlation was seen between the ASO titer and the age of the horses. There was a significant difference between mean ASO titer in horses 0-2 years and horses 2-10 years In horses older than 10 years the titer was significantly higher than mean ASO titer for the group. Twenty four of 30 horses in which ASO titer was higher or equal to 80 I.U. had histories which suggested that streptococcal infection had occurred. Clinical and bacteriolo...
Dinev D, Koĭchev K, Kolev K, Gerganova E.A total of 24 horses and 42 cattle with a variety of local suppurative processes (wounds, abscesses, phlegmons, tendovaginitis, etc.) were studied under conditions of the clinic with regard to the most commonly found microbial species and the opportunity to work out antibioticogrammes in terms of the effectiveness of 11 of the chemotherapeutic agents widely used in the practice. It was found that prevailing in horses were staphylococci and streptococci. In cattle Corynebacterium pyogenes was predominantly established. Besides, there was a rising trend in the part played by representative agent...
Timoney JF.An R antigen of the group C streptococcus S. equi that cross reacts with a similar antigen of S. zooepidemicus has been identified and characterized. It is acid, heat and trypsin resistant, but pepsin sensitive and has an isoelectric point of 4.8. The amino acids in highest concentration are glutamic, aspartic, alanine, leucine, and valine. Bacterial components released in a French Press contain large amounts of R antigen, which is present also in culture supernatants and acid extracts. It has a molecular weight of about 82,000. Trypsin extraction of cells yields molecules of predominantly 56,...
Brown AE, Hansen PJ, Asbury AC.Uterine flushings collected from mares before and after bacterial-induced inflammation were assayed for ability to opsonize Streptococcus zooepidemicus for phagocytosis by polymorphonuclear leukocytes. Opsonization was measured as the peak phagocytic rate of bacteria preincubated with uterine flushings relative to the peak phagocytic rate of unopsonized bacteria. Flushings from four mares with noninfected uteri were unable to opsonize bacteria regardless of whether uteri were flushed at estrus or on day 10 postovulation. In a second experiment, 7 X 10(9) live S. zooepidemicus were inoculated i...
Hoquet F, Higgins R, Lessard P, Vrins A, Marcoux M.A total of 43 horses were used for the study of the pharyngeal bacterial flora. The median value of the number of bacteria in the group of 19 normal horses was 3.8 x 10(4) cfu/g of secretions. This value was 6.4 x 10(4)cfu/g in horses with grade I pharyngitis, 1.3 x 10(5) cfu/g in horses with grade II pharyngitis and 3.5 x 10(6) cfu/g in horses affected with grades III and IV pharyngitis. Corynebacterium spp, coagulase-negative staphylococci, Nocardia spp, Moraxella spp and Enterobacter spp were the most frequently encountered bacteria in the normal animals as well as in horses affected with p...
Galan JE, Timoney JF.Purpura hemorrhagica is an acute disease of the horse characterized by edema of the head and limbs, leucocytoclastic vasculitis, petechial hemorrhages in mucosae, musculature and viscera, and sometimes glomerulonephritis. It is usually associated with strangles, an upper respiratory tract disease of the horse caused by Streptococcus equi. We have detected and characterized immune complexes in the sera of horses with poststrangles purpura hemorrhagica by using PEG precipitation and Western blot analysis. The immune complexes contained IgA and S. equi-specific antigens similar to those found in ...
Srivastava SK, Barnum DA.The ability of either formalin-treated or heat-inactivated whole Streptococcus equi cell vaccines or partially purified M-protein of S. equi to give rise to protective antibody levels was studied in Standardbred foals by serological means. Two commercial preparations, i.e. a beta-propiolactone killed whole S. equi cell bacterin and a cell-free extract of S. equi cells were included in the study. The mean passive hemagglutination antibody titers (10 X log2) in sera of foals given either four doses of formalin-treated whole cell vaccine or an initial dose of formalin-treated followed by three do...
Cheung AT, Liu IK, Walsh EM, Miller ME.The host defense competence of uterine-derived polymorphonuclear leukocytes (PMN) from mares considered resistant (grade I uteri) and susceptible (grade III uteri) to chronic endometritis was evaluated for phagocytic and killing (bactericidal) capacities, using a fluorochrome assay. Peripheral blood PMN from noncategorized mares and from grade I and grade III mares were used as controls. Uterine-derived PMN from mares with grade I uteri were functionally competent for phagocytosis and killing of Candida albicans, whereas uterine-derived PMN from mares with grade III uteri had significantly les...
Wilson WD, Baggot JD, Adamson PJ, Hirsh DC, Hietala SK.Sodium cefadroxil was administered as a single intravenous dose (25 mg/kg) to six healthy adult mares. Plasma samples were collected over a 24-h period and cefadroxil concentrations were measured by microbiological assay. The pharmacokinetic behavior of the drug was appropriately described in terms of a one-compartment open model. Values for the major pharmacokinetic terms were: extrapolated initial plasma concentration = 59.2 +/- 15.0 micrograms/ml; half-life = 46 +/- 20 min; apparent volume of distribution = 462 +/- 191 ml/kg; and body clearance = 7.0 +/- 0.6 ml/min.kg. In a subsequent study...
Timoney JF, Eggers D.An indirect test based on horse blood was used to study bactericidal responses of the horse to Streptococcus equi following infection or vaccination. Bactericidal antibody appeared in convalescent sera between two and four weeks and high titres were usually attained by eight weeks. Infection without clinical evidence of abscessation was also effective in eliciting strong bactericidal responses. Serum bactericidal activity of horses either recovered from strangles or immunised with commercial bacterin had declined eight months after vaccination. However, horses that developed strangles eight to...
Koblik PD, Lofstedt J, Jakowski RM, Johnson KL.Indium 111-labeled autologous leukocytes were used to image an abdominal abscess in a horse with a palpable abdominal mass and history of Streptococcus equi infection. A focal area of radioactivity was identified in the location corresponding to the abscess. Imaging of this focal uptake was optimal 48 hours after injection. Similar scans obtained in 2 clinically normal horses revealed no evidence of focal radioactivity in this region. The cell labeling procedure gave acceptable labeling efficiency (87.5%) but an excessive number of damaged WBC, resulting in persistent lung radioactivity on all...
Bannister MF, Benson CE, Sweeney CR.Two commercial systems, the API 20S (Analytab Products, Plainview, N.Y.) and the Rapid Strep (API System S.A., Montalieu-Vercieu, France), were evaluated for ease of use and accuracy in the rapid identification of group C streptococci isolated from horses. A total of 85 Streptococcus isolates were tested, including S. equi (67 isolates), S. zooepidemicus (13 isolates), and S. equisimilis (5 isolates). All S. equi and S. zooepidemicus isolates were correctly identified within 24 h by the Rapid Strep system. Specific grouping sera was necessary to distinguish between S. equisimilis and group G o...
Liu IK, Cheung AT, Walsh EM, Miller ME, Lindenberg PM.The functional competence of peripheral blood and uterine-derived polymorphonuclear leukocytes (PMN) from 12 mares were analyzed for chemotactic responsiveness using a chemotactic chamber (filter) assay and for deformability by cell elastimetry analysis. Peripheral blood PMN obtained from control mares and from 8 mares experimentally inoculated via the uterus with 1 x 10(9) Streptococcus zooepidemicus had similar normal chemotactic responsiveness and were highly deformable before and at 12 hours after inoculation. Uterine PMN obtained 12 hours after uterine inoculation with S zooepidemicus fro...
Timoney JF, Trachman J.Immunologically reactive proteins in acid extracts and culture supernatants of Streptococcus equi were recognized through a combination of chromatographic and immunologic procedures. Both high- and low-molecular-weight components of each of these protein preparations were protective for mice and were, therefore, presumed to contain a variety of hydrolytic products or fragments of the M protein of S. equi. Convalescent horse sera that exhibited strong bactericidal activity for S. equi always reacted with polypeptides in the molecular weight range of 24,000 to 29,000, whereas preinfection sera d...
Balke E, Weiss R, Seipp A.A total of 110 strains of beta-hemolytic streptococci, belonging to serogroup C (Lancefield), isolated from horses (71 S. zooepidemicus, 27 S. equisimilis and 12 S. equi) as well as 5 reference strains were tested for their ability to produce hyaluronidase. The determinations were carried out in a culture test on agarose gel and in a liquid test system (turbidity test according to DiFerrante). The results of both methods used showed that the three Streptococcus species could be differentiated by the relative quantitative determination of hyaluronidase activity. S. equisimilis strains produce 5...
Galan JE, Timoney JF.Mucosal nasopharyngeal immunoglobulin A (IgA) and IgG responses to proteins of Streptococcus equi were studied in horses after the experimental production of strangles. S. equi-specific IgA and IgG titers in nasopharyngeal mucus were much higher in samples from animals 1 to 2 weeks after challenge than in samples from control animals. Although IgA was the major immunoglobulin in nasal mucus, there was more antibody activity associated with IgG as measured by radioimmunoassay. Great differences between the specificities of antibodies in nasal mucus and in serum were detected. IgA and IgG of muc...
Srivastava SK, Barnum DA, Prescott JF.The production of M-protein antigen of Streptococcus equi was studied during in vitro growth in equine blood and in various media. Of 11 S equi strains studied, seven which had initially possessed 0.04 mg or less M-protein per 10 mg of streptococcal cell extract showed an increase in M-protein content after successive culture in heparinised horse blood. Maximum proliferation occurred in Todd-Hewitt (TH) medium with added 0.2 per cent w/v glucose when compared with TH medium alone or TH medium with 2 per cent w/v sucrose, starch, neopeptone or normal horse serum. The M-protein of these strains ...
Rigg DL, Ramey DW, Reinertson EL.Respiratory distress and laryngeal paralysis were found to be caused by a Streptococcus equi abscess of cranial mediastinal lymph nodes, putting pressure on the trachea at the thoracic inlet. Surgical drainage was required to relieve the compression, and long-term antibiotic therapy was used to treat the bacterial infection. The trachea returned to normal diameter but left laryngeal hemiplegia persisted. Peritracheal abscesses should be considered in the differential diagnosis of inspiratory dyspnea of the horse.
Baggot JD, Love DN, Rose RJ, Raus R.The serum concentrations of the aminoglycosides neomycin, kanamycin and streptomycin were determined after intravenous (iv) and intramuscular (im) administration. These values were then related to the minimum inhibitory concentrations (MIC) of a number of equine pathogenic bacteria to determine the duration of therapeutic serum concentrations of the aminoglycosides in the horse. Pharmacokinetic analysis of the data using neomycin as the example revealed a mean (+/- sd) peak serum concentration of 23.2 +/- 10.2 micrograms/ml present at 30 mins, and at 8 h the serum concentration was 2.8 +/- 0.8...
Benson CE, Sweeney CR.Streptococcus pneumoniae type 3 was isolated from seven tracheobronchial aspirates and one pleural tap of seven adult horses and one foal. There was no direct evidence in these horses that isolation of the pneumococcus was related to a specific disease syndrome. Presenting complaints included two horses with chronic cough, two horses with decreased exercise tolerance, one horse with exercise-induced pulmonary hemorrhage, and three horses with pneumonia. Antibiotic therapy resolved the primary clinical complaint. This is the first report of the isolation of S. pneumoniae type 3 from adult horse...
Higgins R, Biberstein EL, Jang SS.Of 24 isolates of nutritionally variant streptococci recovered from equine corneal ulcers, 22 were tested for growth requirements, physiological and biochemical reactions, and susceptibility to different antimicrobial agents. Satisfactory growth was obtained by supplementing blood agar and Todd-Hewitt broth with pyridoxal hydrochloride, and all of the media for the culture and the biochemical testing were supplemented with 0.002% of this substance. Biochemical patterns of 12 of the isolates resembled those of two viridans streptococcal species, Streptococcus intermedius and Streptococcus const...
Tzipori S, Hayes J, Sims L, Withers M.Streptococcus durans was isolated from a foal with profuse watery diarrhea and caused a similar syndrome when inoculated into foals via the orogastric route. The most consistent and striking histological feature was the extensive colonization of the mucosal surface of the small intestine by S. durans. Associated mucosal changes were mild to modeate, and brush border lactase and alkaline phosphatase production were depressed. S. durans also induced acute diarrhea in young gnotobiotic piglets. Mucosal changes were mild and, as with foals, the mucosal surface of the small intestine was colonized ...
Varma KJ, Powers TE, Powers JD, Spurlock SL.A reproducible experimental disease model in horses using Streptococcus zooepidemicus was developed. An intravenous challenge dose of 1 X 10(10) colony-forming units (CFU), followed 24 h later with another challenge of 1 X 10(8) CFU of Strep. zooepidemicus produced the desired disease model. The disease was characterized by depression, pyrexia, anorexia, abnormal lung sounds, inflammation of joints, moderate to severe lameness, gradual loss of condition and emaciation. The effects of the disease on hematology, serum chemical profile and different protein fractions were studied. The disease sta...
Powers JD, Powers TE, Varma KJ, Gabel AA, Spurlock SL.Quantification of the clinical manifestations of a disease has been a serious problem particularly as related to clinical trials or drug efficacy studies. Historically, this quantification has been limited to categorizing each patient into one of three or four groups, e.g. worse, no improvement, improved. This problem becomes serious when an investigation utilizes an experimentally induced animal disease model. A health index, which quantifies the clinical state of horses which have an experimentally induced beta-hemolytic streptococcal infection, is described. Aspects of experimental design a...
Asbury AC, Gorman NT, Foster GW.The addition of serum to uterine secretions was shown to opsonize Streptococcus zooepidemicus and significantly enhance bacterial phagocytosis by equine neutrophils. Treatment of serum by heat inactivation at 56 degrees C, EDTA treatment, and C3 consumption reduced phagocytosis and therefore demonstrated that the process was complement-dependent. The amount of C3 present in uterine secretions was measured in a series of 14 mares infected with Streptococcus zooepidemicus . Ten of the 14 mares had detectable amounts of C3; however, the C3 had been cleaved and rendered nonfunctional. The importan...
Piché CA.An outbreak of strangles, which occurred during the spring, summer and fall of 1980 on a Standardbred stud farm in eastern Alberta is described. The infective organism, Streptococcus equi, may have been introduced by an outside mare that was brought to the stud for breeding. All of the groups of horses on the farm were affected. For the most part, the disease was allowed to run its natural course. Only severely affected individuals were treated. During the outbreak, the foals were prophylactically treated with penicillin to prevent them from contracting the disease. Ten horses died of complica...
Srivastava SK, Barnum DA.Streptococcus equi was found to adhere to tongue, cheek and nasal epithelial cells of ponies, in vitro. Maximum adherence was observed at pH 7.5 after one hour of incubation of bacteria with epithelial cells. This adherence was more on epithelial cells from adult animals than from foals. Streptococci exposed to heat (60 degrees C for 10 min) or treated with pepsin or trypsin showed a reduced adherence, whereas an increase occurred on treatment with hyaluronidase. Antibodies against whole S. equi cells or M-like protein blocked the adherence, whereas antibodies against group-specific carbohydra...
Ducharme NG, Dill SG, Shin SJ, Schwark WS, Ducharme GR, Beilman WW.This preliminary study evaluated phenoxymethyl penicillin (Penicillin V) as an alternative to parenteral administration of penicillin in horses. Penicillin V was administered orally to five horses at two different doses and plasma levels of the drug were determined at timed intervals. The results were evaluated by regression analysis. Following the administration of penicillin V at a dose of 66,000 IU/kg or 110,000 IU/kg, the mean peak plasma levels obtained were 1.55 micrograms/mL and 2.34 micrograms/mL respectively. A plasma level two to four times above the minimal inhibitory concentration ...
Verheyen K, Newton JR, Talbot NC, de Brauwere MN, Chanter N.Three protracted outbreaks of strangles were investigated using endoscopic examination and a total of 14 asymptomatic carriers of Streptococcus equi were identified of which 13 showed evidence of carriage in the guttural pouch. Treatment was initiated to eliminate S. equi colonisation since these animals posed an infectious risk to susceptible horses. Two further horses were referred to us with severe guttural pouch pathology and from which S. equi was cultured, and treatment of these cases is also described. Treatment in the first instance was directed towards removal of gross guttural pouch ...
Geraghty TE, Love S, Taylor DJ, Heller J, Mellor DJ, Hughes KJ.The sites of insertion of catheters into the jugular veins of six horses were investigated to determine common isolates and to assess the effectiveness of two disinfection protocols with the hair coat left long, clipped or shaved. Skin commensals (Staphylococcus, Streptococcus and Micrococcus species) and environmental contaminants (Bacillus, Enterobacteriaceae, Aspergillus and Mucor species) were the microorganisms most frequently isolated. Chlorhexidine gluconate and povidone-iodine-based skin disinfection protocols resulted in significant reductions in the number of bacterial isolates from ...
Bostedt H, Lehmann B, Peip D.Based on a group of 33 mares infected with mastitis, data regarding the time of appearance, the clinical symptoms and the bacteriological causes of the disease were evaluated. The cases were distributed as follows: 27.3% before delivery, 24.2% immediately after delivery (until the third day), 12.1% during the middle and late stages of lactation, 9.1% immediately after the weaning of the foal and 27.3% outside the lactation period of non-pregnant mares. The clinical picture is described. In the majority of the cases, both halves of the udder were infected. The analysis of the bacteriological re...
Wallace FJ, Emery JD, Cripps AW, Husband AJ.The ability of mucosally administered antigen to provide protection against Streptococcus equi ('Strangles') infections in horses was examined. First, an enzyme linked immunosorbent assay (ELISA) was developed to detect the immune status of horses to S. equi. This assay was used to select Strangles-naive horses for the study and also to monitor their response to immunisation. Potential vaccine candidates were: (a) orally administered paraformaldehyde killed S. equi; (b) intraperitoneally (IP) administered paraformaldehyde killed S. equi in a non-inflammatory adjuvant; (c) orally administered l...
Ma X, Wang C, Zhang B, Xia L, Su Y.Strangles is a highly prevalent, extremely contagious, and occasionally lethal infectious disease affecting horses worldwide. Prophylactic antibiotics are ineffective in prevention of disease but are recommended for exposed horses at the first sign of fever and any horse obviously ill from strangles or with complications and there is an urgent need of a cost-effective, safe, efficacious vaccine. In the present study, we sought to develop effective vaccines by fusing the Streptococcus equi subspecies equi (S. equi) antigen SeM with the flagellin of Salmonella abortus equi FljB. We also explored...
Powers JD, Powers TE, Varma KJ, Gabel AA, Spurlock SL.Quantification of the clinical manifestations of a disease has been a serious problem particularly as related to clinical trials or drug efficacy studies. Historically, this quantification has been limited to categorizing each patient into one of three or four groups, e.g. worse, no improvement, improved. This problem becomes serious when an investigation utilizes an experimentally induced animal disease model. A health index, which quantifies the clinical state of horses which have an experimentally induced beta-hemolytic streptococcal infection, is described. Aspects of experimental design a...
D￮ LR, Stefanovski D, Boston RC, Boyle AG.To evaluate predictor variables for and complications associated with Streptococcus equi subsp equi infection (strangles) in horses. Methods: Retrospective case-control study. Methods: 108 horses with strangles (cases) and 215 horses without strangles (controls). Methods: Medical records from January 2005 through July 2012 were reviewed. Cases were defined as horses with clinical signs of strangles (pyrexia, retropharyngeal lymphadenopathy, and mucopurulent nasal discharge) that were associated with a confirmed strangles outbreak or had positive results for S equi on PCR assay or bacteriologic...
Judy CE, Chaffin MK, Cohen ND.To identify features of guttural pouch (auditory tube diverticulum) empyema in horses and compare findings of uncomplicated guttural pouch empyema with guttural pouch empyema complicated by chondroids. Methods: Retrospective study. Methods: 91 horses with guttural pouch empyema. Methods: Medical records of horses with guttural pouch empyema were reviewed. Results: The most common owner complaint and abnormal finding was persistent nasal discharge. Chondroids were detected in 21% (19/91) of affected horses. Streptococcus equi was isolated from the guttural pouch in 14 of 44 horses; for Streptoc...
Kawakami V, Rietberg K, Lipton B, Eckmann K, Watkins M, Oltean H, Kay M, Rothschild C, Kobayashi M, Van Beneden C, Duchin J.On March 17, 2016, Public Health-Seattle & King County in Washington was notified of two persons who received a diagnosis of Streptococcus equi subspecies zooepidemicus (S. zooepidemicus) infections. S. zooepidemicus is a zoonotic pathogen that rarely causes human illness and is usually associated with consuming unpasteurized dairy products or with direct horse contact (1). In horses, S. zooepidemicus is a commensal bacterium that can cause respiratory, wound, and uterine infections (2). The health department investigated to determine the magnitude of the outbreak, identify risk factors, and o...
Morris ERA, Schroeder ME, Ferro PJ, Waller AS, McGlennon AA, Bustos CP, Gressler LT, Wu J, Lawhon SD, Boyle AG, Lingsweiler S, Paul N, Dimitrov K....Strangles is a contagious bacterial disease of horses caused by Streptococcus equi subspecies equi (SEE) that occurs globally. Rapid and accurate identification of infected horses is essential for controlling strangles. Because of limitations of existing PCR assays for SEE, we sought to identify novel primers and probes that enable simultaneous detection and differentiation of infection with SEE and S. equi subsp. zooepidemicus (SEZ). Comparative genomics of U.S. strains of SEE and SEZ (n = 50 each) identified SE00768 from SEE and comB from SEZ as target genes. Primers and probes for real-ti...
Gosai F, Gosai N.Strangles is a contagious upper respiratory tract infection primarily affecting equines. It is rare disease with zoonotic transmission. It is caused by the bacterium, . We present the rare case of strangles in an elderly patient complicated by bacteraemia, osteomyelitis and native valve endocarditis. The patient was treated successfully with appropriate antibiotics and no surgical intervention was needed. In an age of accelerated emerging zoonosis, this is an important entity clinicians should be aware of to prevent delay in diagnosis and poor outcome. Conclusions: Strangles is a disease of eq...
Srivastava SK, Barnum DA.Lymphocyte stimulation was observed in whole equine blood in the presence of phytohaemagglutinin and M protein extracted from a typical strain of Streptococcus equi. Blood samples were collected from several healthy horses and horse and pony foals and cultured in vitro with varying concentrations of phytohaemagglutinin and M protein for several days. Phytohaemagglutinin was found to induce lymphocyte stimulation in these animals. Highest mean stimulation indices in horse foals (49.3 +/- 24.4) and pony foals (54.7 +/- 32.0) were observed with 0.625 and 1.25 micrograms/mL phytohaemagglutinin, re...
Boyle A.Streptococcus equi subspecies equi (strangles) is a highly contagious upper respiratory infection in horses. The infection is transmitted by inhalation or direct contact with mucopurulent discharge from an infective animal, resulting in fever, depression, and submandibular and retropharyngeal lymph node enlargement that can lead to respiratory distress. Complications include purpura hemorrhagica and metastatic abscessation. Control of outbreaks requires strict isolation protocols and hygiene measures. Detection of carriers is essential for preventing disease recurrence on a farm.
sub. (SEZ) is described as a commensal bacterium of several animal species, including humans. Growing evidence supports the potential role of SEZ in the onset and progression of severe clinical manifestations of diseases in horses and other animals. In the present communication, we describe the diagnostic procedure applied to characterize the streptococcal infections caused by a novel SEZ sequence type (ST525) in donkeys raised on a farm in Abruzzo, Italy. The diagnostic process began with anamnesis and anatomopathological analysis, which revealed a severe bacterial suppurative bronchopneumo...
Morrell JM, Klein C, Lundeheim N, Erol E, Troedsson MH.Bacteria (environmental contaminants and occasionally potential pathogens) are found in most stallion ejaculates and may negatively affect sperm quality during storage. Since the use of antibiotics can lead to the development of resistance, an alternative means of microbial control is desirable. The removal of bacteria from stallion semen using Single Layer Centrifugation through Androcoll-E was investigated. Known doses of cultured bacteria were added to freshly collected ejaculates (15mL aliquots) before processing by Single Layer Centrifugation. The resulting sperm pellets and controls (not...
Wilson WD, Baggot JD, Adamson PJ, Hirsh DC, Hietala SK.Sodium cefadroxil was administered as a single intravenous dose (25 mg/kg) to six healthy adult mares. Plasma samples were collected over a 24-h period and cefadroxil concentrations were measured by microbiological assay. The pharmacokinetic behavior of the drug was appropriately described in terms of a one-compartment open model. Values for the major pharmacokinetic terms were: extrapolated initial plasma concentration = 59.2 +/- 15.0 micrograms/ml; half-life = 46 +/- 20 min; apparent volume of distribution = 462 +/- 191 ml/kg; and body clearance = 7.0 +/- 0.6 ml/min.kg. In a subsequent study...
Cohen ND, Cywes-Bentley C, Kahn SM, Bordin AI, Bray JM, Wehmeyer SG, Pier GB.Strangles is a common disease of horses with worldwide distribution caused by the bacterium Streptococcus equi subspecies equi (SEE). Although vaccines against strangles are available commercially, these products have limitations in safety and efficacy. The microbial surface antigen β 1→6 poly-N-acetylglucosamine (PNAG) is expressed by SEE. Here we show that intramuscular (IM) injection alone or a combination of IM plus intranasal (IN) immunization generated antibodies to PNAG that functioned to deposit complement and mediate opsonophagocytic killing of SEE ex vivo. However, immunization st...
Delph KM, Beard LA, Trimble AC, Sutter ME, Timoney JF, Morrow JK.Streptococcus equi subspecies equi infection elicits M protein antibody titers in equids. Interpretation of titers is not generally accepted. Objective: The magnitude of S. equi M protein (SeM) antibody titer after infection (titer ≥1:12 800) will be useful to monitor for the presence of complications or the risk of development of complications. Methods: Forty-eight horses on 1 farm involved in strangles outbreak. Methods: Clinical and observational study. S. equi M protein antibody titers were measured on all horses 8 weeks after infection and select horses 12 and 28 weeks after infecti...
Fenger CK, Kohn CW.A 20-month-old Quarter Horse stallion was admitted for evaluation of labored breathing, honking cough, and bilateral epistaxis that were caused by pneumonia and collapsed trachea. A transtracheal aspiration revealed highly cellular, serosanguineous fluid. Radiography revealed a patchy alveolar pattern and a narrowed tracheal lumen. Endoscopy confirmed narrowing of the tracheal lumen. Streptococcus zooepidemicus was isolated on culture of the transtracheal aspirate. The horse responded to penicillin treatment, and the tracheal collapse improved endoscopically after 4 days, with complete recover...
Rodrigues MA, Figueiredo L, Padrela L, Cadete A, Tiago J, Matos HA, Gomes de Azevedo E, Florindo HF, Gonçalves LM, Almeida AJ.Strangles is an extremely contagious and sometimes deadly disease of the Equidae. The development of an effective vaccine should constitute an important asset to eradicate this worldwide infectious disease. In this work, we address the development of a mucosal vaccine by using a Supercritical Enhanced Atomization (SEA) spray-drying technique. Aqueous solutions containing the Streptococcus equi extracts and chitosan were converted into nanospheres with no use of organic solvents. The immune response in a mouse model showed that the nanospheres induced a well-balanced Th1 and Th2 response charac...
Hoffman AM, Viel L, Prescott JF, Rosendal S, Thorsen J.Undifferentiated distal respiratory tract disease (nasal discharge, cough, pneumonia) in foals (1 to 8 months old) is a burdensome economic problem on breeding farms; yet, the infective agents associated with these episodes have not been well described. Possible causes of these episodes of illness were investigated by culturing specimens of proximal and distal airways of clinically diseased foals (n = 101), prior to any treatment, for aerobic and anaerobic bacteria and viruses (rhinoviruses, equine arteritis virus, equine herpesvirus subtype 1 [EHV-1], influenza virus, and adenovirus). Pairs o...
Frippiat T, Paindaveine C, Duprez JN, Delguste C, Mainil J, Art T.Antimicrobial resistance is increasing in both human and veterinary medicine. Bacteria can be part of the etiology of respiratory disorders in horses. Bactericidal activity of silver has been largely described and silver is currently used in veterinary therapeutic applications such as wound dressings. The aim of this study was to assess the in vitro bactericidal effects of nebulized silver nanoparticles (AgNP) on 2 common equine respiratory bacteria, Streptococcus equi subsp. zooepidemicus and Actinobacillus equuli subsp. equuli. Firstly, antimicrobial susceptibility of AgNP was determined ove...
Léon A, Castagnet S, Maillard K, Paillot R, Giard JC.The present study described the evolution of antimicrobial resistance in equine pathogens isolated from 2016 to 2019. A collection of 7806 bacterial isolates were analysed for their in vitro antimicrobial susceptibility using the disk diffusion method. The most frequently isolated pathogens were group C Streptococci (27.0%), Escherichia coli (18.0%), Staphylococcus aureus (6.2%), Pseudomonas aeruginosa (3.4%), Klebsiella pneumoniae (2.3%) and Enterobacter spp. (2.1%). The majority of these pathogens were isolated from the genital tract (45.1%, n = 3522). With the implementation of two French n...
Alber J, El-Sayed A, Lämmler C, Hassan AA, Weiss R, Zschöck M.The closely related streptococcal species Streptococcus equi subsp. zooepidemicus and S. equi subsp. equi were identified by polymerase chain reaction using oligonucleotide primers designed according to species-specific parts of the superoxide dismutase A encoding gene sodA. A further differentiation of both subspecies could be performed by amplification of the genes seeH and seeI encoding the exotoxins SeeH and SeeI, respectively, which could be detected for S. equi subsp. equi but not for S. equi subsp. zooepidemicus. A further simplification of the identification and differentiation of both...
Velineni S, Breathnach CC, Timoney JF.Streptococcus zooepidemicus (Sz) is a tonsillar commensal of healthy horses but with potential to opportunistically invade the lower respiratory tract. Sz is genetically variable and recombinogenic based on analysis of gene sequences including szp, szm and MLST data. Although a variety of serovars of the protective SzP are commonly harbored in the tonsils of the same horse, lower respiratory infections usually involve a single clone. Nevertheless, isolation of specific clones from epizootics of respiratory disease has been recently reported in horses and dogs in N. America, Europe and Asia. In...
Laus F, Preziuso S, Spaterna A, Beribè F, Tesei B, Cuteri V.An outbreak of strangle-like disease involving 26 horses farmed in central Italy was investigated by clinic examination, endoscopy, cytology, bacteriology and polymerase chain reaction (PCR). At weekly interval, a total of three nasal swabs and one guttural pouches lavage fluid (GPLF) were collected, and no Streptococcus equi subsp. equi carrier was found. Some horses showed upper airways disease and endoscopic signs of pharyngeal lymphoid hyperplasia of different grade and/or abnormal endoscopic appearance of guttural pouches. Streptococcus dysgalactiae subsp. equisimilis was isolated from 14...
Crabill MR, Cohen ND, Martin LJ, Simpson RB, Burney N.Equine synovial fluid aliquots were inoculated with Salmonella enteritidis, Escherichia coli, Actinobacillus equuli, Staphylococcus aureus, and Streptococcus zooepidemicus to obtain approximate concentrations of 1000, 100, 10, and 1 colony forming U/mL. Synovial fluid aliquots were also inoculated with an unquantitated inoculum of Bacteroides fragilis and Clostridium perfringens. Inoculated synovial fluid was incubated in trypticase-soy broth or Columbia broth for approximately 12 hours. Then aliquots were removed for DNA extraction and polymerase chain reaction (PCR) analysis for detection of...
Weese JS, Saab M, Moore A, Cai H, McClure JT.To compare PCR and culture results for the detection of subspecies . Respiratory tract samples (N = 158) from horses being tested for Bacterial culture was carried out on samples from which was detected by quantitative real-time PCR. was isolated from 12 (7.6%) samples: 4/9 (44%) samples when the PCR cycle threshold (C) was ≤ 30, 7/30 (23%) when the C was 30.1 to 35, and 1/119 (0.8%) when the C was 35.1 to 40. The highest C sample from a sample that yielded a positive culture was 36.9. The optimal Youden's J value was at a C of 34.2, the same value as determined by number needed to misdi...
Ortega J, Daft B, Assis RA, Kinde H, Anthenill L, Odani J, Uzal FA.Omphalitis and the resulting septicemia contribute to perinatal mortality in several animal species. In foals, the most important causes of omphalitis are Escherichia coli and Streptococcus zooepidemicus. However to date, no information has been published about the role of Clostridium sordellii in these infections. In this paper, we describe 8 cases of perinatal mortality in foals associated with internal umbilical remnant infection by C. sordellii. The foals studied were between 12 and 21 days old at the time of death, and various breeds were represented in the group. Five of the foals were m...
Durham AE, Kemp-Symonds J.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. Objective: 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. Methods: 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 antibo...
