Topic:Streptococcus
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.
Infectious agents in acute respiratory disease in horses in Ontario. A study of acute respiratory disease in horses in Ontario was undertaken to determine the identity of current causative infectious agents. A nasopharyngeal swab was designed and utilized to maximize isolation of viruses, mycoplasma, and pathogenic bacteria. Serum samples were collected for parallel determination of antibody titers to equine influenza virus type A subtype 1 (H7N7) and subtype 2 (H3N8), equine rhinovirus types 1 and 2, equine herpesvirus type 1, Mycoplasma equirhinius, and Mycoplasma felis. Equine rhinovirus type 2 was recovered from 28/92 horses tested, and equine influenza vir...
Clinical efficacy of ampicillin, pivampicillin and procaine penicillin G in a soft tissue infection model in ponies. Tissue chambers, implanted subcutaneously in ponies, were inoculated with Streptococcus zooepidemicus. The animals received either no antibiotics or one of the following treatments: pivampicillin per os (19.9 mg/kg, equivalent to 15 mg/kg ampicillin, every 12 h) for 7 or 21 days (7 and 5 ponies, respectively), procaine penicillin G intramuscularly (12 mg/kg = 12,000 IU/kg, every 24 h) for 7 days (7 ponies), or ampicillin sodium intravenously (equivalent to 15 mg/ kg ampicillin, every 8 h) for 1 day (5 ponies). Only intravenous administration was started before infection (prophylactically), the...
Separation of equine IgG subclasses (IgGa, IgGb and IgG(T)) using their differential binding characteristics for staphylococcal protein A and streptococcal protein G. Equine IgG possesses four well-defined subisotypes, designated IgGa, IgGb, IgGc and IgG(T) on the basis of their increasing anodal mobility in electrophoresis. However, the preparation of IgGa and IgGb reference proteins has not previously been reported. Certain bacterial cell wall proteins, termed protein A and protein G, have been used for purification of IgG subisotypes from the serum of domestic animals which, combined with other techniques utilising differences in the physico-chemical properties of the proteins, has allowed the purification of Ig isotypes. This paper describes purificatio...
Distribution of penicillins into subcutaneous tissue chambers in ponies. The distribution of penicillins into a tissue chamber implanted subcutaneously in ponies was studied. Ampicillin sodium (equivalent to 15 mg/kg ampicillin) was administered intravenously. Pivampicillin, a prodrug of ampicillin, was administered by nasogastric tube to fed ponies at a dose of 19.9 mg/kg (equivalent to 15 mg/kg ampicillin). Procaine penicillin G was administered intramuscularly at a dose of 12 mg/kg (equivalent to 12000 IU/kg). Six ponies were used for each medication. Antibiotic concentrations in plasma and tissue chamber fluid (TCF) were measured for 24 h after administration. ...
Respiratory disease in thoroughbred horses in training: the relationships between disease and viruses, bacteria and environment. A longitudinal study of respiratory disease in racehorses was carried out to assess its relative associations with different infectious agents and to examine any role that the environmental conditions might play. The relationships between coughing, nasal discharge, pyrexia and lower respiratory tract disease were also examined to provide information for improving clinical diagnosis, particularly of disease of the lower respiratory tract. Lower airway disease was closely associated with infection with Streptococcus zooepidemicus. It was also found that equine herpesvirus seroconversions and S p...
Detection of bacteria in equine synovial fluid by use of the polymerase chain reaction. 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...
Effects of potentiated chlorhexidine on bacteria and tarsocrural joints in ponies. To evaluate the bactericidal properties of chlorhexidine diacetate (CHD) after potentiation with EDTA and Tris buffer (EDTA-Tris), and to find a potentiated CHD concentration that would achieve 90 to 100% killing for all bacteria tested. Methods: 6 adult ponies. Methods: Serial dilutions of CHD, CHD in EDTA-Tris and EDTA-Tris alone were evaluated for bactericidal activity against Staphylococcus aureus, Escherichia coli, and Streptococcus zooepidemicus. The tarsocrural joints of 6 ponies were lavaged with either 1 L phosphate-buffered saline solution (control) or 1 L of 0.0005% CHD in EDTA-Tris...
Bacterial pneumonia associated with corticosteroid therapy in three horses. 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...
[Jenner’s cowpox vaccine in light of current vaccinology]. Two hundred years ago Edward Jenner inoculated James Phipps with vaccinia and 181 years later smallpox had disappeared from the surface of the earth as a result of generalized vaccination. Compared to the requirements of modern vaccinology, the procedures used by Jenner and his successors, were extremely primitive because of an almost total lack of knowledge in the field of microbiology and immunology. The active principle of smallpox vaccine is vaccinia virus, which in many respects, differs from that of natural cowpox; the term "cowpox" has been used for more than a century and a half to des...
Pharmacokinetics and therapeutic potential for repeated oral doses of trimethoprim/sulphachlorpyridazine in horses. The pharmacokinetic parameters of a powder formulation of trimethoprim/sulphachlorpyridazine were studied in eight healthy horses which received 5 mg/kg trimethoprim and 25 mg/kg sulphachlorpyridazine 12-hourly with concentrate for five days. The intake of the medicated concentrate by the horses was variable during the first two days, but after they became accustomed to the taste the intake by all the horses during the last three days was good. Faecal samples taken before and on the last day of the drug administrations were negative when cultured for salmonella. Compared with the results of a ...
An assessment of mucosal immunisation in protection against Streptococcus equi (‘Strangles’) infections in horses. 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...
Pathology of equine respiratory disease occurring in association with transport. Eight young thoroughbred horses, taken 1858 km by road (travelling time, 41 h), were examined to assess the pathological nature of respiratory disease associated with transport. Three of the horses showed clinical abnormalities including pyrexia, coughing, leucocytosis and neutrophilia after the first 20 h of transportation. Endoscopical examination of the trachea revealed exacerbation of airway inflammation as a result of transport in two of the three affected horses. A consistent finding in the affected horses was focal serous neutrophilic pneumonia affecting the cranio-ventral portion of th...
Retropharyngeal lymph node infection in horses: 46 cases (1977-1992). A retrospective study of 46 horses with retropharyngeal lymph node (RPLN) infection presented to the Rural Veterinary Centre between 1977 and 1992 was undertaken. Horses aged less than one year were most commonly represented (46%). Thirty-nine percent of cases had been exposed to horses with confirmed or suspected strangles (Streptococcus equi subsp equi infection) within the previous 8 weeks. Most frequent signs were unilateral or bilateral swelling of the throat region (65%), respiratory stertor/dyspnoea (35%), purulent nasal discharge (20%), inappetence and signs of depression (15%), and dy...
[Susceptibility of bacterial isolates from the equine respiratory tract to trimethoprim, sulfadoxine, sulfadimethoxine and combinations of these compounds]. Using a broth microdilution technique, the in vitro susceptibility of bacterial isolates from the equine respiratory tract to trimethoprim, sulfadoxine, sulfadimethoxine, and combinations of these compounds was determined. The bacterial strains (n = 88) isolated recently from horses with respiratory symptoms belonged to the following species: Streptococcus equi subsp. zooepidemicus (n = 34), Streptococcus equi subsp. equi (n = 22), Staphylococcus aureus (n = 9), Klebsiella pneumoniae (n = 7), Rhodococcus equi (n = 4), Pseudomonas spp. (n = 3) and Escherichia coli (n = 3). In addition, two isol...
Comparative treatment of mares susceptible to chronic uterine infection. Four intrauterine treatment strategies were evaluated for effectiveness in mares that were confirmed to be susceptible to chronic uterine infection. Pretreatment samples were obtained at detection of estrus, and a genital strain of Streptococcus zooepidemicus was infused into the uterus when a preovulatory (> 35 mm) follicle was detected. At 12 hours after inoculation, mares were assigned to 1 of 4 selected treatment groups: autologous plasma, 100 ml (n = 5); potassium penicillin, 5 million U in 100 ml of phosphate-buffered saline solution (PBSS; n = 5); 10 mg of prostaglandin F2 alpha in 1...
Cloning and sequence analysis of a protective M-like protein gene from Streptococcus equi subsp. zooepidemicus. Streptococcus equi subsp. zooepidemicus, a Lancefield group C streptococcus, is a frequently isolated opportunist pathogen from a variety of animal hosts, including the horse. Previous studies have indicated that equine strains carry antigens with characteristics of the antiphagocytic M proteins on the Lancefield groups A and G streptococci. We have cloned a protective M-like protein gene (SzPW60) of an equine strain of S. equi subsp. zooepidemicus W60 and determined its sequence. This gene encodes a protein with a molecular weight of 40,123 which protects mice against subsp. zooepidemicus but...
Antiphagocytic properties of uterine isolates of Streptococcus zooepidemicus and mechanisms of killing in freshly obtained blood of horses. A total of 22 clinical streptococcal isolates, predominantly Streptococcus zooepidemicus, associated with endometritis in horses were tested for their ability to withstand the natural bactericidal properties of freshly obtained blood. During a 3-hour incubation in blood from a single horse, 8 of these isolates survived and grew, the remainder were killed. To determine whether this ability to grow extended to blood of other horses, 5 of these growing isolates were tested for their ability to grow in the blood of 5 additional horses. The same 5 horses were used for each isolate. The isolates gre...
Immunisation of mares to control endometritis caused by Streptococcus zooepidemicus. Normal mares were immunised by the intramuscular and intrauterine administration of an antigen with adjuvant and they and unimmunised control mares were later challenged by the intrauterine instillation of pathogenic Streptococcus zooepidemicus; the response of all the mares was monitored clinically and bacteriologically for seven days. Significantly fewer S zooepidemicus were present in cervical swabs taken from the immunised mares than from the control mares (P < 0.01) and the degree of inflammation in the genital tract of the immunised mares was also significantly less (P < 0.001). Th...
Eosinophilic keratoconjunctivitis in a horse. An 11-year-old Quarter Horse gelding was evaluated because of a persistent, raised band of 1- to 2-mm subepithelial plaques of the left cornea. Cytologic examination of corneal scrapings revealed numerous eosinophils and segmented neutrophils, with few mast cells, plasma cells, and lymphocytes. Bacteriologic culture yielded sparse growth of alpha-hemolytic Streptococcus and Staphylococcus spp. Histologically, the plaques consisted of subepithelial foci of fragmented and degenerated collagen fibers infiltrated by eosinophils and neutrophils, with few lymphocytes, plasma cells, and macrophages. ...
Genetic structure of populations of beta-haemolytic Lancefield group C streptococci from horses and their association with disease. The genetic structure of beta-haemolytic Lancefield group C streptococci isolated from horses in Australia was examined by multilocus enzyme electrophoresis. The 249 isolates comprised 70 classified phenotypically as Streptococcus equi subspecies equi, 177 classified as S equi subspecies zooepidemicus and two which were unclassifiable. Forty-one electrophoretic types were identified which could be classified into three major clusters, A, B and C. Of the isolates, 178 fell into cluster B (types 4 to 22) and lay within a genetic distance of 0.36. Sixty-nine of the 70 S equi subspecies equi isola...
Characterization of a novel streptokinase produced by Streptococcus equisimilis of non-human origin. Streptokinases are proteins with plasminogen activator activity produced by certain hemolytic streptococci. We previously identified equine streptococcal isolates which produced streptokinases (ESKs) that bound both human and equine plasminogen but only readily activated equine plasminogen (14). This property was exploited to purify a representative ESK produced by Streptococcus equisimilis strain 87-542-W. Affinity chromatography with human plasminogen resulted in the isolation of a M(r) approximately 49,000 molecule with two isoforms. This ESK was subsequently compared to well characterized ...
Review of 40 cases of lung abscesses in foals and adult horses. A retrospective study of 40 horses with primary lung abscesses without pleuropneumonia showed that lung abscesses occurred predominantly in young horses, usually in foals aged < or = 6 months. Hyperfibrinogenaemia was present in all but 2 horses, and other common clinical and haematological findings were hyperthermia, tachycardia, polypnoea, and neutrophilic leucocytosis. The most common bacterial species isolated from transtracheal aspirates were Streptococcus zooepidemicus (20/34) and Rhodococcus equi (13/34). Most horses (23/27) discharged from the hospital were long term survivors. Of t...
Characterization of the antiphagocytic activity of equine fibrinogen for Streptococcus equi subsp. equi. The antiphagocytic property of equine fibrinogen for Streptococcus equi subsp. equi strain CF32 was examined in vitro. The results of bactericidal assays demonstrated that the presence of fibrinogen enhanced the ability of overnight and early log-phase cultures of strain CF32 to resist killing by equine neutrophils by 12-fold and seven-fold, respectively (p > 0.01). In addition, fibrinogen-coated bacteria treated with fibrinogen specific F(ab')2 fragments were 32% more susceptible to killing by equine neutrophils after opsonization in serum (p > 0.05), indicating that specific epitopes o...
Pathology of equine pneumonia associated with transport and isolation of Streptococcus equi subsp. zooepidemicus. Seven horses that died of pneumonia associated with transport yielded Streptococcus equi subsp. zooepidemicus (S.z.) from their pulmonary lesions. These lesions were divisible roughly into two types, serous haemorrhagic pneumonia and multiple foci of coagulative necrosis, which were considered to reflect a temporal difference in the process of lesion formation. Immunohistologically, S.z. antigen was detected in both types of lesion. Acute necrotic lacunar tonsillitis was considered to play an important role in the onset of the pneumonia.
Influence of estrous cycle stage on adhesion of Streptococcus zooepidemicus to equine endometrium. Equine endometria representative of Kenney's categories I, II, and III were incubated in vitro with phosphate buffer, Streptococcus pneumoniae, or S zooepidemicus. Endometrial tissues from mares in estrus and diestrus were first categorized according to Kenney's classification, then were tested for adherence of S pneumoniae and S zooepidemicus to the epithelia. Bacteria were not observed when the endometrial tissue was incubated with phosphate buffer or S pneumoniae. There was no statistical difference in attachment of S zooepidemicus to endometrial tissue from mares in estrus or diestrus if e...
Purification of a plasminogen activator from Streptococcus uberis. A protein capable of activating bovine, equine and ovine plasminogen, but not that from human or porcine plasma, was purified from culture filtrates of Streptococcus uberis (strain 0140J). Purification was achieved by ammonium sulphate precipitation followed by molecular exclusion chromatography. The elution position of the native molecule was equivalent to a molecular mass of approximately 57 kDa. However, the molecular mass, as determined by SDS-PAGE, was 29 kDa, suggesting the existence of a dimeric structure. Purified immunoglobulin from three out of five monoclonal antibodies raised to th...
Influence of estrogen on antibacterial and immunoglobulin secretory activities of uterine fluids from ovariectomized mares. Effect of estrogen (E2) and progesterone (P4) on uterine antibacterial activity and immunoglobulin concentrations in mares was studied. In 2 in vitro experiments, 6 mixed-breed mares were ovariectomized, and uterine fluid and blood serum were analyzed. Antibacterial assay methods were used to determine inhibitory effects on Streptococcus zooepidemicus of uterine fluid samples collected on days 3, 5, and 8, and serum obtained on day 8 of treatment. Single radial immunodiffusion methods were used to quantify amounts of IgA and IgG in uterine fluid and serum on days 3, 5, 8, and 14 of treatment. ...
Epidemiologic and immunologic characteristics of Streptococcus equi infection in foals. A 2-phase study was performed to characterize the effects of Streptococcus equi infection in unexposed and previously exposed foals. In phase I, 22 weanling foals involved in a naturally occurring S equi epizootic were studied, along with a comparison group of 11 unexposed foals, matched for age, sex, and breed. Six months later (phase II), an epizootic was experimentally induced in previously exposed and unexposed foals from phase I. The prevalence and duration of clinical signs, the relative risk of developing disease, bacteriologic culture results, hematologic responses, and mucosal and ser...