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.
Manguin E, Pépin E, Boivin R, Leclere M.There are limited data on potential dysbiosis of the airway microbiota in horses with asthma. Objective: We hypothesized that the respiratory microbiota of horses with moderate asthma is altered. Our objectives were (a) to quantify tracheal bacterial populations using culture and qPCR, (2) to compare aerobic culture and qPCR, and (c) to correlate bacterial populations with bronchoalveolar lavage fluid (BALF) cytology. Methods: Eighteen horses with moderate asthma from a hospital population and 10 controls. Methods: Prospective case-control study. Aerobic culture was performed on tracheal aspir...
Dziubinski N, Mählmann K, Lübke-Becker A, Lischer C.Surgical site infection (SSI) with multiresistant bacteria is an important cause of postoperative morbidity after laparotomy in horses. The objective of this study was to identify bacteria isolates and their antibiotic resistance patterns associated with the development of wound infection in horses after laparotomy. This is a retrospective case series. Medical records of horses that underwent ventral midline exploratory laparotomy in a four-year period at one equine hospital were reviewed. Results of microbiologic culture and susceptibility testing are described. The study group consisted of 1...
Pringle J, Storm E, Waller A, Riihimäki M.Antibiotic treatment of horses with strangles is reported to impair the development of immunity to subsequent exposure to Streptococcus equi ssp equi (S. equi). However, apart from a single clinical report, evidence-based studies for this hypothesis are lacking. Objective: To determine whether penicillin treatment during clinical strangles influences the development or persistence of seropositivity to S. equi-specific antibodies. Methods: A natural outbreak of strangles with 100% morbidity in 41 unvaccinated mature Icelandic horses. Methods: A prospective longitudinal study of acute clinical s...
Ikhuoso OA, Monroy JC, Rivas-Caceres RR, Cipriano-Salazar M, Barbabosa Pliego A.Although the strangles disease of Streptococcus equi was discovered many decades ago in 1,251 by Jordanus Ruffus, it has still remained a major frequently diagnosed infection in horses all over the world. The S. equi subspecies pathogen is known to be often resistant to antibiotic treatment, and it makes the antibiotics inefficient; hence, this review was conducted to study how the disease can be managed. The age-long sign of this infection is the oozing of pus through the mucous and skin membranes. Affected horses lose appetite, develop fever, and become depressed, which result in them losin...
Fernandes CB, Ball BA, Loux SC, Boakari YL, Scoggin KE, El-Sheikh Ali H, Cogliati B, Esteller-Vico A.Anatomical and molecular changes in the cervical barrier in women are a fundamental part of the pathogenesis of pregnancy loss associated with chorioamnionitis. However, there is little information regarding changes in the cervix associated with ascending infection in pregnant mares. To better characterize morphological and molecular changes in the cervix during placentitis, we examined full thickness histology and mRNA expression for a number of inflammatory and endocrine factors in the mucosa and stroma of the cervix of mares (n = 5) after experimental induction of placentitis via transc...
Fedorka CE, Ball BA, Scoggin KE, Loux SC, Troedsson MHT, Adams AA.Ascending placentitis is one of the leading causes of abortion in the horse. Minimal work has focused on its effect on fetal fluids or the antenatal immune response of the fetus. Placentitis was induced via transcervical inoculation of Streptococcus equi ssp Zooepidemicus, and fluids/serum/tissues were collected 4-6 days later following euthanasia. Cytokine concentrations were detected using a multiplex immunoassay within fetal fluids (amniotic and allantoic) and serum (maternal and fetal) in inoculated and control mares. In addition, tissues from fetal (spleen, liver, lung, umbilicus, amnioa...
Glatter M, Borewicz K, van den Bogert B, Wensch-Dorendorf M, Bochnia M, Greef JM, Bachmann M, Smidt H, Breves G, Zeyner A.The objective of this study was to investigate the impact of natural prebiotic active compounds on the microbial composition in different regions of the equine gastrointestinal tract. Twelve adult horses (body weight [bwt] 534 ± 64.5 kg; age 14 ± 7.5 years) were randomly divided into two feeding groups. Six horses received a basal diet consisting of 1.5 kg hay/100 kg bwt x d-1 and oat grains equal to 1.19 g starch/kg bwt x d-1, supplemented with Jerusalem artichoke meal providing prebiotic fructooligosaccharides + inulin in a quantity of 0.15 g/kg bwt x d-1. The remaining horses received a p...
Mustikka MP, Grönthal TSC, Pietilä EM.To retrospectively describe laboratory findings, treatment, and outcome associated with equine infectious keratitis in Finland. Unassigned: Medical records of horses diagnosed with infectious keratitis in University of Helsinki Equine Hospital from January 2007 to June 2018 were reviewed. Results: Forty-seven cases were included. Keratomycosis was diagnosed in 27 eyes and bacterial keratitis in 20 eyes. Aspergillus flavus was the most frequent fungal isolate (9/17, 53%), followed by Cylindrocarpon sp. (3/17, 18%) and Aspergillus fumigatus (2/17, 12%). Susceptibility was tested for 10/11 Asperg...
MacFadyen AC, Waller AS, Paterson GK.Strain 28462T, which had Gram-stain-positive, catalase-negative coccus-shaped cells, was isolated from a routine tracheal sample from a 3 year old thoroughbred horse. 16S rRNA gene sequence analysis revealed it to be most closely related to, but distinct from, Streptococcus henryi (95.7 % identity), Streptococcusplurextorum (95.8 %), Streptococcusporci (96.4 %) and Streptococcus caprae (95.1 %). Similarity values derived from sequences from sodA and rpoB genes were consistent with strain 28462T belonging to a species distinct from these four streptococci. At the whole genome level, str...
Pusterla N, Bowers J, Barnum S, Hall JA.The objective of this study was to detect Streptococcus equi subspecies equi (S. equi) (Lactobacillales: Streptococcaceae) using quantitative polymerase chain reaction (qPCR) in flies collected from a farm with a documented outbreak of strangles. A total of 1856 face flies [Musca autumnalis (Diptera: Muscidae)] were collected using conventional fly traps. The flies were processed for nucleic acid purification and tested for the presence of S. equi by qPCR. A total of 10/1856 flies (0.54%) tested qPCR-positive for S. equi. The results may implicate the presence of face flies as a risk factor...
Von Dollen KA, Jones M, Beachler T, Harris TL, Papich MG, Lyle SK, Bailey CS.The use of antimicrobials for the management of equine uterine disease is commonplace, with antibiotic selection generally based on empirical evidence or in vitro sensitivity results. However, the potential disconnect between these laboratory results and clinical efficacy in the mare raises concern for antibiotic failure and subsequent development of resistant organisms. In this work, we attempt to bridge this gap by using an ex vivo model of the equine postpartum uterus to quantitatively evaluate the antimicrobial activity of two commonly used antibiotic treatments in the mare (ceftiofur an...
Bourély C, Cazeau G, Jarrige N, Haenni M, Gay E, Leblond A.Horses are one of the potential reservoirs of antimicrobial resistance (AMR) determinants that could be transferred to human subjects. Objective: To describe the AMR patterns of major bacteria isolated from diseased horses in France. Methods: Retrospective observational study. Methods: Data collected between 2012 and 2016 by RESAPATH, the French national surveillance network for AMR, were analysed. Only antimicrobials relevant in veterinary and human medicine for the isolated bacteria were considered. Mono- and multidrug resistance were calculated. The resistance proportions of major equine di...
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...
El-Sheikh Ali H, Legacki EL, Loux SC, Esteller-Vico A, Dini P, Scoggin KE, Conley AJ, Stanley SD, Ball BA.The current study aimed to elucidate the mechanisms underlying myometrial activation during equine placentitis related to progestogens and the progesterone receptor signaling pathways. Placentitis was induced via intracervical inoculation with Streptococcus equi ssp zooepidemicus in mares at approximately 290 days of gestation (placentitis group; n = 6) with uninoculated gestationally matched mares as controls (n = 4). Mares in the placentitis and control groups were euthanized, and myometrial samples were collected from two regions: region 1-parallel to active placentitis lesion with plac...
Canisso IF, Loux S, Scoggin KE, Squires EL, Troedsson MH, Ball BA.Characterisation of fetal fluids in healthy and disease states of pregnant mares can help to unravel the pathophysiology and to identify putative markers of disease. Thus, this study aimed to compare the protein composition of: (1) amniotic and allantoic fluids of healthy mares obtained immediately after euthanasia and (2) allantoic fluid harvested via centesis before and after experimental induction of placentitis via transcervical inoculation of Streptococcus equi ssp zooepidemicus in healthy mares. Fetal fluids were analysed with a high-throughput proteomic technique after in-gel digestion....
Borkent D, Reardon RJM, McLACHLAN G, Glendinning L, Dixon PM.Although, peripheral caries (PC) affects almost half of UK horses, no comprehensive microbiological study has been performed on this disorder. As a high proportion of oral bacteria cannot be conventionally cultured, molecular microbiological techniques such as Next Generation Sequencing are required to examine the complex oral bacteria community. Objective: To identify the microbiota involved in equine PC, including comparing microbiota at the more commonly and severely affected three caudal cheek teeth with the less commonly affected three rostral cheek teeth. Methods: Equine dental plaque sa...
Frye CC, Bei D, Parman JE, Jones J, Houlihan AJ, Rumore A.Streptothricosis is a dermatitis characterized by matted tufts of hair and coalescing, pustular crusts that affects many livestock species, including horses. It results from cutaneous infection by the actinobacterium Dermatophilus congolensis. For economic reasons, the ailment is often treated with commercially available over-the-counter (OTC) products or home remedies rather than prescribed medications. This study aimed to determine the efficacy of tea tree oil (TTO), an essential oil of Melaleuca alternifolia, as an OTC treatment for streptothricosis. Bacteria were isolated from presumptive ...
Kasuya K, Tanaka N, Oshima F, Fujisawa N, Saito M, Tagami K, Niwa H, Sasai K.Strangles is a commonly diagnosed and important infectious disease of equids worldwide, caused by Streptococcus equi subsp. equi. We determined the SeM genotypes of S. equi isolated from imported horses at the Japanese border within the past 8 years, which allowed us to classify 12 strains isolated from these horses from each exporter into four allelic groups. These alleles were different from the alleles of past isolates found in Japan. Furthermore, four strains classified into the same allele were isolated from horses from one exporter over several years. In this study, S. equi isolates from...
Dong J, Gao N, Waller AS, Cook FR, Fan S, Yuan D, Du Y, Li F, Norimine J, Zhu W.Strangles is a highly contagious respiratory disease of equids caused by the bacterium Streptococcus equi subspecies equi. Objective: To identify the cause of an outbreak of strangles that occurred on donkey farms within the Shandong Province of China and determine the prevalence of the disease. Methods: Cross-sectional. Methods: Samples were taken from clinically affected animals to measure the prevalence of strangles within the population of donkeys at six intensive farms in China and identify the SeM type of isolate recovered from affected animals. Diagnosis was confirmed by bacterial isola...
Loux SC, Fernandes CB, Dini P, Wang K, Wu X, Baxter D, Scoggin KE, Troedsson MHT, Squires EL, Ball BA.Intrauterine infection and inflammation remain a major cause of preterm labour in women and mares, with little known about small RNA (sRNA) expression in tissue or circulation. To better characterise placental inflammation (placentitis), we examined sRNA expression in the endometrium, chorioallantois and serum of mares with and without placentitis. Disease was induced in 10 mares via intracervical inoculation of Streptococcus equi ssp. zooepidemicus, either with moderate or high levels of inoculum; three uninoculated gestationally matched mares were used as controls. Matched chorioallantois an...
Duchesne R, Castagnet S, Maillard K, Petry S, Cattoir V, Giard JC, Leon A.This study aimed to analyse antimicrobial susceptibility evolution of equine pathogens isolated from clinical samples from 2006-2016. A collection of 25 813 bacterial isolates was studied, clustered according to their origins (respiratory tract, cutaneous, genital and other), and analysed for their antimicrobial susceptibility using the disk diffusion method. The most frequently isolated pathogens were group C Streptococci (27.6%), Escherichia coli (20.0%), Staphylococcus aureus (7.8%), Pseudomonas aeruginosa (4.0%), Enterobacter spp. (3.4%), Klebsiella pneumoniae (2.4%), and Rhodococcus equi ...
Pringle J, Venner M, Tscheschlok L, Bächi L, Riihimäki M.After strangles outbreaks, Streptococcus equi ssp. equi (S. equi) can persist in clinically normal silent carriers for months to years. Two naturally occurring outbreaks of strangles with 53 and 100% morbidity, respectively, were followed longitudinally to assess occurrence of carrier state and optimal detection methods Outbreak A involved 98 yearling warmbloods, and outbreak B 38 mature Icelandic horses. Fully recovered horses were sampled at least 6 months after index cases using nasal swabs (one sampling occasion only) nasopharyngeal lavage and guttural pouch visualisation and lavages for c...
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...
Wynn MAA, Ball BA, May J, Esteller-Vico A, Canisso I, Squires E, Troedsson M.The objectives of this study were to compare via liquid chromatography-tandem mass spectrometry (LC-MS/MS) progesterone (P4), 5α-dihydroprogesterone (DHP), allopregnanolone, 3β-hydroxy-5α-pregnan-20-one (3β5P), 20α-hydroxy-5α-pregnan-3-one (20α5P), 5α-pregnan-3β,20α-diol (βα-diol), and 5α-pregnan-3β,20β-diol (ββ-diol) concentrations in plasma of mares with experimentally-induced, ascending placentitis compared to gestationally age-matched control mares. Placentitis was induced via intracervical inoculation of Streptococcus equi spp. zooepidemicus between 260 and 280 days of ge...
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: ...
Riihimäki M, Aspán A, Ljung H, Pringle J.The aim of the study was to use culture, qPCR and seM sequencing to map Streptococcus equi subspec. equi (S.equi) isolates in long term carrier animals. A strangles outbreak affecting 41 Icelandic horses was followed to determine strangles free status using nasal and/or guttural pouch lavages collected serially on eleven separate occasions over 13 months. Ten persistent carriers, of which eight had repeated culture positive samples for S. equi, were selected for the study. Of 115 samples collected, 61 were S. equi positive on qPCR; from which 32 were also culture positive. Amplification of par...
Gergeleit H, Verspohl J, Rohde J, Rohn K, Ohnesorge B, Bienert-Zeit A.Diagnostics in equine sinusitis can be challenging and often require a combination of different imaging tools to ascertain its underlying aetiology. The bacterial flora of healthy and diseased paranasal sinuses, respectively, has only sporadically been assessed in horses. The objectives of this study were to determine whether assessment of microbiological features of secretions from the paranasal sinuses displays a useful diagnostic tool in equine sinusitis to distinguish between different aetiologies. Secretion samples from 50 horses with sinusitis and from 10 healthy horses were taken transe...
Müller V, Curcio BR, Toribio RE, Feijó LS, Borba LA, Canisso IF, Nogueira CEW.This study aimed to evaluate steroid hormones in foals born from mares treated for ascending placentitis with different combinations of trimethoprim-sulfamethoxazole (TMS), flunixin meglumine (FM), long-acting altrenogest (ALT) and estradiol cypionate (ECP) for ten consecutive days, starting two days after experimental induction of placentitis with Streptococcus zooepidemicus. Fourty-six pregnant mares and respective foals were assigned as healthy group (Control, n = 8) or treated groups as follows: TMS+FM (n = 8), TMS+FM+ALT (n = 8), TMS+FM+ALT+ECP (n = 6), TMS+FM+ECP (n = 6) and no...
Høyer-Nielsen AK, Gaini S, Kjerulf A, Kollslíð R, Steig TÁ, Stegger M, Jóanesarson J. subspecies () is mostly known as an opportunistic pathogen found in horses and as a rare human zoonosis. An 82-year-old male, who had daily contact with horses, was admitted in a septic condition. The patient presented with dyspnea, hemoptysis, impaired general condition, and severe pain in a swollen left shoulder. Synovial fluid from the affected joint and blood cultures showed growth of subsp. . Transesophageal echocardiography showed a vegetation on the aortic valve consistent with endocarditis. Arthroscopic revision revealed synovitis and erosion of the rotator cuff. Technetium-99m scin...
Laing G, Christley R, Stringer A, Aklilu N, Ashine T, Newton R, Radford A, Pinchbeck G.Pathogens are frequently implicated in equine respiratory disease. In Ethiopia, respiratory disease is a frequent cause for presentation at veterinary clinics and a priority concern for users of working horses. However, there is little existing literature on possible aetiologies. Objective: Determine prevalence of respiratory signs and exposure to major respiratory pathogens through a serological survey. Methods: Cross-sectional. Methods: Systematically selected horses from 19 sites in central Ethiopia were examined clinically and sampled once (August-December 2013). A face-to-face interview c...
Lindsay AM, Zhang M, Mitchell Z, Holden MTG, Waller AS, Sutcliffe IC, Black GW.Streptococcus equi causes equine 'strangles'. Hyaluronate lyases, which degrade connective tissue hyaluronan and chondroitins, are thought to facilitate streptococcal invasion of the host. However, prophage-encoded hyaluronate lyases are hyaluronan-specific and are thought to be primarily involved in the degradation of the hyaluronan capsule of streptococci during bacteriophage infection. To understand the role of prophage-encoded hyaluronate lyases further, we have biochemically characterized such a hyaluronate lyase, SEQ2045 from S. equi, and have shown that it is produced during equine infe...
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...
Pringle J, Venner M, Tscheschlok L, Bächi L, Riihimäki M.After strangles outbreaks, Streptococcus equi ssp. equi (S. equi) can persist in clinically normal silent carriers for months to years. Two naturally occurring outbreaks of strangles with 53 and 100% morbidity, respectively, were followed longitudinally to assess occurrence of carrier state and optimal detection methods Outbreak A involved 98 yearling warmbloods, and outbreak B 38 mature Icelandic horses. Fully recovered horses were sampled at least 6 months after index cases using nasal swabs (one sampling occasion only) nasopharyngeal lavage and guttural pouch visualisation and lavages for c...
Manguin E, Pépin E, Boivin R, Leclere M.There are limited data on potential dysbiosis of the airway microbiota in horses with asthma. Objective: We hypothesized that the respiratory microbiota of horses with moderate asthma is altered. Our objectives were (a) to quantify tracheal bacterial populations using culture and qPCR, (2) to compare aerobic culture and qPCR, and (c) to correlate bacterial populations with bronchoalveolar lavage fluid (BALF) cytology. Methods: Eighteen horses with moderate asthma from a hospital population and 10 controls. Methods: Prospective case-control study. Aerobic culture was performed on tracheal aspir...
Li J, Zhao Y, Gao Y, Zhu Y, Holyoak GR, Zeng S.Bacterial infections are the main causes of endometritis in mares. It is well known that the most common bacterial pathogen is Streptococcus equi subspecies zooepidemicus (SEZ). This structured review was completed according to the PRISMA procedure to search endometritis treatment protocols published between 1990 and 2020 it was our intent to evaluate the actual effects of different treatment protocols for endometritis caused by SEZ. The trials included were collected from Pubmed, CAB and Agricola. Ten articles with 116 horses and 17 different interventions were identified. The results of this...
Cordoni G, Williams A, Durham A, Florio D, Zanoni RG, La Ragione RM.Strangles is one of the most common equine infectious diseases with serious health, welfare and socio-economic impact. However, the detection of Streptococcus equi subspecies equi can be challenging and persistently infected carriers are common. Furthermore, the use of classical microbiology can result in an underestimation of the prevalence of the disease. The difficulties associated with the slow diagnosis of Strangles can result in rapid spread of the disease. Therefore, rapid and economical diagnostic tests are urgently required. Here, two multiplex assays, were developed and validated for...
Lee H, Yun SH, Hyon JY, Lee SY, Yi YS, Choi CW, Jun S, Park EC, Kim SI.Streptococcus equi subspecies equi is a pathogenic bacterium that causes strangles, a highly contagious respiratory infection in horses and other equines. The limitations of current vaccines against S. equi infection warrants the development of an affordable, safe, and effective vaccine. Because gram-positive extracellular vesicles (EVs) transport various immunogenic antigens, they are attractive vaccine candidates. Here, we purified the EVs of S. equi ATCC 39506 and evaluated them as a vaccine candidate against S. equi infection in mice. As an initial step, comparative proteomic analysis was ...
Schroeder B, Boyle MD, Sheerin BR, Asbury AC, Lottenberg R.Our laboratory previously demonstrated that group C streptococcal isolates from humans and horses secrete streptokinases that preferentially activate plasminogens reflecting the origin of the isolates. To analyze the significance of these findings, series of streptokinase-producing Streptococcus equisimilis isolates recovered from humans and horses were examined. Southern blot analysis revealed that chromosomal DNA of the streptococcal isolates from humans reacted exclusively with a skc(hu) probe and that chromosomal DNA of streptococcal isolates from horses reacted preferentially with an skc(...
Sheoran AS, Sponseller BT, Holmes MA, Timoney JF.Equine strangles, caused by the clonal pathogen Streptococcus equi, is a source of serious economic loss despite the widespread use of commercial vaccines. The anti-phagocytic 58 kDa M-like protein (SeM) is an important protective antigen. The objective of this study was to define differences, if any, between SeM-specific convalescent serum and mucosal IgA and IgG subisotypes and those induced by vaccination with commercial strangles vaccine. SeM-specific opsonophagocytic IgGb was the predominant serum antibody in horses intramuscularly vaccinated or recently recovered from infection. Infectio...
Troedsson MH, Liu IK, Thurmond M.In vitro phagocytosis and chemotaxis of uterine and blood-derived polymorphonuclear neutrophils (PMNs) were compared in mares with different resistance to chronic uterine infection (CUI). Both the primary in vitro function of PMNs and the role of uterine environmental factors on PMN function were investigated. The uteri of mares susceptible to (n = 6) and resistant to CUI (n = 5) were inoculated with 5 x 10(6) Streptococcus zooepidemicus when the mares were in estrus. Uterine secretions in addition to uterine and blood-derived PMNs were sampled at 5 and 24 h later. During a subsequent estrus, ...
Downar J, Willey BM, Sutherland JW, Mathew K, Low DE.We report a case of group C streptococcal meningitis in a woman with a history of close animal contact as well as head trauma as a result of a kick by a horse. Blood and cerebrospinal fluid cultures grew Streptococcus equi subsp. zooepidemicus, as did a throat culture taken from the colt that had kicked her 2 weeks prior to admission.
McGlennon A, Waller A, Verheyen K, Slater J, Grewar J, Aanensen D, Newton R.Previously national surveillance data for monitoring strangles (Streptococcus equi infection) in UK horses was limited. Improved awareness and knowledge of positive diagnoses would permit the optimisation of biosecurity protocols, decreasing the prevalence of strangles. Methods: Seven UK laboratories reported positive strangles diagnoses between 1 January 2015 and 31 December 2019 based on identifying Streptococcus equi via agent detection assays from field-based practitioner-submitted samples. Associated clinical history and animal signalment were collected where provided, and descriptive ana...
Yoshikawa H, Yasu T, Ueki H, Oyamada T, Oishi H, Anzai T, Oikawa M, Yoshikawa T.To evaluate the possibility that Streptococcus equi subsp. zooepidemicus (S.z) the causative bacterial agent of equine shipping fever pneumonia (ESFP), as well as to investigate its pathogenesis, 10 horses (seven Thoroughbreds and three Anglo-Arab species, ranging from 2-4 years in age) were experimentally inoculated, via an endoscope, into bronchus of the lung lobe with a dose of 30 ml of 1-7 x 10(8) CFU/ml of S.z. After inoculation, autopsy and pathological examinations were sequentially conducted 30 min, 1, 2, 3, 4, 17, 20 hr and 2 weeks later. Pneumonia induced by the intrapulmonary inocul...
Chanter N, Talbot NC, Newton JR, Hewson D, Verheyen K.The M-protein genes of Streptococcus equi isolated from 17 outwardly healthy horses after 4 strangles outbreaks had ended, including a quarantined animal, were compared with those of S. equi isolates from 167 active cases of strangles across 4 countries. The healthy horses included 16 persistent S. equi carriers, at least one from each of the four outbreaks. These carriers, despite being outwardly healthy, had empyema of the guttural pouch(es), an enlargement of the equine Eustachian tube. A persistent carrier from two of these outbreaks, the quarantined animal and a healthy animal with normal...
Troedsson MH, Liu IK.The purpose of this study was to investigate the physical ability of the mare's uterus to eliminate non-antigenic 51Cr microspheres during an infectious challenge. Mares both potentially susceptible and resistant to chronic uterine infections were used in this study. The procedure described serves as a model of the uterine capacity to clear physically infectious agents and inflammatory products during the acute phase of an infection. Based on the results from intra-uterine bacterial challenges, reproductive history, examination per rectum and endometrial biopsies, mares were classified as pote...
Pringle J, Storm E, Waller A, Riihimäki M.Antibiotic treatment of horses with strangles is reported to impair the development of immunity to subsequent exposure to Streptococcus equi ssp equi (S. equi). However, apart from a single clinical report, evidence-based studies for this hypothesis are lacking. Objective: To determine whether penicillin treatment during clinical strangles influences the development or persistence of seropositivity to S. equi-specific antibodies. Methods: A natural outbreak of strangles with 100% morbidity in 41 unvaccinated mature Icelandic horses. Methods: A prospective longitudinal study of acute clinical s...
Akter R, El-Hage CM, Sansom FM, Carrick J, Devlin JM, Legione AR.Abortion in horses leads to economic and welfare losses to the equine industry. Most cases of equine abortions are sporadic, and the cause is often unknown. This study aimed to detect potential abortigenic pathogens in equine abortion cases in Australia using metagenomic deep sequencing methods. Results: After sequencing and analysis, a total of 68 and 86 phyla were detected in the material originating from 49 equine abortion samples and 8 samples from normal deliveries, respectively. Most phyla were present in both groups, with the exception of Chlamydiae that were only present in abortion sa...
Firth EC, Nouws JF, Driessens F, Schmaetz P, Peperkamp K, Klein WR.The plasma penicillin concentrations were determined in 5 horses given an IV injection of sodium penicillin G; plasma penicillin concentrations were also determined in a crossover experiment, where animals were given procaine penicillin G subcutaneously at 1 site and IM at 4 sites. The mean penicillin plasma peak concentration and bioavailability were highest after the drug was injected in the neck and biceps musculature. Injections in the gluteal muscle and in the subcutaneous sites resulted in similar, but lower, more persistent penicillin plasma concentrations and a lower bioavailability th...
Christoffersen M, Söderlind M, Rí»ºlk SR, Pedersen HG, Allen J, Krekeler N.Infectious endometritis is a major cause of infertility in the mare and inflicts major losses on the equine breeding industry. The ability of the mare to eliminate uterine infections has been studied intensively for decades; however, despite identification of several factors contributing to the multifactorial pathogenesis and improved treatment, infectious endometritis remains a significant problem in a subpopulation of broodmares. Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) is one of the most commonly isolated pathogens from the uterus of mares, suffering from infectious endom...
Meyer S, Giguère S, Rodriguez R, Zielinski RJ, Grover GS, Brown SA.The objectives of this study were to determine pharmacokinetics of intravenous (i.v.) ceftiofur in foals, to compare ultra-high performance liquid chromatography tandem mass spectometry (UPLC-MS/MS) and microbiologic assay for the measurement of ceftiofur concentrations, and to determine the minimum inhibitory concentration (MIC) of ceftiofur against common equine bacterial pathogens. In a cross-over design, ceftiofur sodium was administered i.v. to six foals (1-2 days-of-age and 4-5 weeks-of-age) at dosages of 5 and 10 mg/kg. Subsequently, five doses of ceftiofur were administered i.v. to six...
Torpiano P, Nestorova N, Vella C.Streptococcus equi subsp. equi is a group C β-hemolytic streptococcus, and is an invasive pathogen with a very restricted host, causing the equine infection known as 'strangles'. It is a poor colonizer in horses, preferentially causing invasion and infection, compared with its ancestor Streptococcus equi subsp. zooepidemicus, which is considered an opportunistic commensal of the equine upper respiratory tract. In humans, S. equi subsp. equi causes invasive infections in immunocompromised hosts, often following close contact with horses. Such infections are associated with a high mortality, as...
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 ...
Høyer-Nielsen AK, Gaini S, Kjerulf A, Kollslíð R, Steig TÁ, Stegger M, Jóanesarson J. subspecies () is mostly known as an opportunistic pathogen found in horses and as a rare human zoonosis. An 82-year-old male, who had daily contact with horses, was admitted in a septic condition. The patient presented with dyspnea, hemoptysis, impaired general condition, and severe pain in a swollen left shoulder. Synovial fluid from the affected joint and blood cultures showed growth of subsp. . Transesophageal echocardiography showed a vegetation on the aortic valve consistent with endocarditis. Arthroscopic revision revealed synovitis and erosion of the rotator cuff. Technetium-99m scin...
Mumford EL, Traub-Dargatz JL, Carman J, Callan RJ, Collins JK, Goltz KL, Romm SR, Tarr SF, Salman MD.Horses vaccinated against common agents of infectious upper respiratory disease (IURD) may not have detectable serum antibody and may not be protected from clinical disease. Objective: The objectives of this study were to 1) investigate the serological response of horses to vaccination against influenza virus (H3N8 and H7N7) and equine herpesviruses (EHV) in a field setting and 2) evaluate associations among vaccination status, serum antibody concentrations, and occurrences of IURD in monitored horses. Methods: In this study, horses on 6 Colorado premises were vaccinated parenterally against i...
May JP, Walker CA, Maskell DJ, Slater JD.Streptococcus equi subsp. equi is the causative agent of the equine disease strangles. In this study we describe the development of an in vivo Himar1 transposon system for the random mutagenesis of S. equi and, potentially, other Gram-positive bacteria. We demonstrate efficient and random transposition of a modified mini-transposon onto the chromosome by Southern blot analysis and insertion site sequencing. Non-haemolytic mutants were isolated at a frequency of 0.2%, and acapsular mutants at a frequency of 0.04%. Taken together, these data demonstrate that in vivo Himar1 mutagenesis can be use...
Boschwitz JS, Timoney JF.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...
Sangiorgio DB, Hilty M, Kaiser-Thom S, Epper PG, Ramseyer AA, Overesch G, Gerber VM.Equine pastern dermatitis (EPD) is a common dermatological problem in horses, yet its aetiology and pathogenesis are poorly understood. Objective: This study aimed to investigate the effects of lesion severity and topical antimicrobial treatment on bacterial flora of EPD-affected skin. Methods: Sixteen horses with EPD were investigated. Methods: An observational study was conducted by assigning a clinical severity score ranging from 0 (macroscopically nonlesional) to 21 (severe), and sampling the most and least severely affected limbs of 16 horses (32 limbs) for bacteriological culture and 16S...
Tiwari R, Qin A, Artiushin S, Timoney JF.Evasion of phagocytosis is an important virulence determinant of Streptococcus equi (S. equi subsp. equi), the cause of equine strangles and distinguishes it from the closely related but much less virulent S. zooepidemicus (S. equi subsp. zooepidemicus). We describe Se18.9, a novel H factor binding protein secreted by S. equi but not by S. zooepidemicus that reduces deposition of C3 on the bacterial surface and significantly reduces the bactericidal activity of equine neutrophils suspended in normal serum for both S. equi and S. zooepidemicus. Se18.9 is secreted abundantly by actively dividing...
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...
