Staphylococcus is a genus of bacteria commonly found on the skin and mucous membranes of horses. These bacteria can be part of the normal flora but may also act as opportunistic pathogens, leading to infections under certain conditions. In horses, Staphylococcus species can cause a range of infections, including skin infections, wound infections, and more severe conditions such as septicemia. The most frequently identified species in equine infections is Staphylococcus aureus, known for its ability to resist certain antibiotics, complicating treatment efforts. This page compiles peer-reviewed research studies and scholarly articles that explore the epidemiology, pathogenic mechanisms, and treatment strategies of Staphylococcus infections in horses.
Toombs-Ruane LJ, Riley CB, Kendall AT, Hill KE, Benschop J, Rosanowski SM.To describe antimicrobial susceptibility, and identify antimicrobial resistance (AMR), in bacteria isolated from New Zealand foals. Methods: A database search was performed of submissions to a veterinary pathology laboratory between April 2004 and December 2013 for bacterial culture of samples from foals <3 weeks of age. Culture and susceptibility results were compiled with demographic information. Susceptibility results were as defined for the Kirby-Bauer disk diffusion susceptibility test based on Clinical Laboratory Standards Institute guidelines. Multi-drug resistance (MDR) was defined as ...
Petinaki E, Spiliopoulou I.Methicillin-resistant Staphylococcus aureus (MRSA) remains one of the most virulent human pathogens and has also recently been recognized as such in the veterinary settings. Companion animals, including dogs, cats, horses, small exotic animals, wildlife animals, and livestock, may constitute a reservoir for MRSA transmission to humans and vice versa. The evolution, emergence, and risk factors for MRSA transmission among colonized or infected animals are reviewed in the present paper, and infection control practices are discussed.
Kuroda T, Kinoshita Y, Niwa H, Mizobe F, Ueno T, Kuwano A, Hatazoe T, Hobo S.We report the first case of methicillin-resistant Staphylococcus aureus (MRSA) keratitis in a racehorse. A 5-year-old mare developed punctate keratitis after racing. The corneal ulcer continued to expand despite ophthalmic antimicrobial therapy. On day 6, a conjunctival graft surgery was performed. The mare was euthanized, following colitis and laminitis development on day 10. MRSA was isolated from the corneal swab taken at the time of euthanasia. Immunohistochemical analysis demonstrated gram-positive and anti-S. aureus monoclonal antibody-positive cocci infiltration of the corneal stroma; a...
Tirosh-Levy S, Steinman A, Carmeli Y, Klement E, Navon-Venezia S.Methicillin-resistant staphylococci (MRS), and specifically Methicillin-resistant Staphylococcus aureus (MRSA) colonization or infection have become a serious emerging condition in equine hospitals, with complex concerns regarding animals, personnel and public health. The objectives of this study were to evaluate the prevalence and risk factors for colonization by Staphylococci, MRS, and MRSA among horses in Israel. Nasal swabs were collected from horses at 17 riding stables (n=206), and from hospitalized horses admitted to a veterinary hospital (n=84). Species identification was performed by ...
Laverty G, McCloskey AP, Gorman SP, Gilmore BF.The threat of antimicrobial resistance has placed increasing emphasis on the development of innovative approaches to eradicate multidrug-resistant pathogens. Biofilm-forming microorganisms, for example, Staphylococcus epidermidis and Staphylococcus aureus, are responsible for increased incidence of biomaterial infection, extended hospital stays and patient morbidity and mortality. This paper highlights the potential of ultrashort tetra-peptide conjugated to hydrophobic cinnamic acid derivatives. These peptidomimetic molecules demonstrate selective and highly potent activity against resistant b...
Maddox TW, Clegg PD, Williams NJ, Pinchbeck GL.Antimicrobial resistance poses a significant threat to the continued successful use of antimicrobial agents for the treatment of bacterial infections. While the epidemiology of antimicrobial resistance in bacteria from man has been studied extensively, less work has been undertaken in companion animals, particularly horses. Methicillin-resistant Staphylococcus aureus has been identified as a cause of infections, with a low prevalence of nasal carriage by horses in the community but higher for hospitalised horses. Molecular characterisation has shown methicillin-resistant Staphylococcus aureus...
Walther B, Janssen T, Gehlen H, Vincze S, Borchers K, Wieler LH, Barton AK, Lübke-Becker A.With the rising importance of nosocomial infections in equine hospitals, increased efforts with regard to biosecurity and infection control are necessary. This even more since nosocomial infections are often associated with multi-drug resistant pathogens. Consequently, the implementation of targeted prevention programs is essential. Since nosocomial infections are usually multifactorial events, realization of only a single measure is rarely effective to overcome nosocomial spread in clinical practice. Equine patients may be colonized at admission with multi-drug resistant pathogens such as met...
Kinoshita Y, Niwa H, Katayama Y.Microbial substitution occasionally occurs following the administration of antimicrobials to horses that have pneumonia or pleuropneumonia. Four specific loop-mediated isothermal amplification (LAMP) assays were developed to detect some equine respiratory pathogens, namely strains of the Bacteroides-Prevotella group, Klebsiella pneumoniae, Stenotrophomonas maltophilia, and Staphylococcus aureus. These four LAMP assays and two previously published LAMP assays targeting Escherichia coli or Pseudomonas aeruginosa were used on clinical respiratory specimens and a high accordance found between the ...
Hidaka S, Kobayashi M, Ando K, Fujii Y.Lomefloxacin is a broad-spectrum fluoroquinolone antibiotic used for the treatment of bacterial extraocular disease. This study investigated the efficacy and safety of lomefloxacin eye drops for bacterial extraocular disease in horses. Lomefloxacin ophthalmic solution (0.3%) was instilled three times daily for 2-5 days in 65 horses diagnosed with bacterial extraocular disease based on clinical findings. Clinical observations and bacteriological examinations were performed at the start of treatment, 2 and 5 days after the start of treatment, and at the discontinuation or termination of treatmen...
Srivastava A, Singh BN, Deepak D, Rawat AK, Singh BR.The discovery of quorum-sensing (QS) systems regulating antibiotic resistance and virulence factors (VFs) has afforded a novel opportunity to prevent bacterial pathogenicity. Dietary molecules have been demonstrated to attenuate QS circuits of bacteria. But, to our knowledge, no study exploring the potential of colostrum hexasaccharide (CHS) in regulating QS systems has been published. In this study, we analyzed CHS for inhibiting QS signaling in Staphylococcus aureus. We isolated and characterized CHS from mare colostrum by high-performance thin-layer chromatography (HPTLC), reverse-phase hig...
Ruzauskas M, Siugzdiniene R, Klimiene I, Virgailis M, Mockeliunas R, Vaskeviciute L, Zienius D.Among coagulase-negative staphylococci, Staphylococcus haemolyticus is the second most frequently isolated species from human blood cultures and has the highest level of antimicrobial resistance. This species has zoonotic character and is prevalent both in humans and animals. Recent studies have indicated that methicillin-resistant S. haemolyticus (MRSH) is one of the most frequent isolated Staphylococcus species among neonates in intensive care units. The aim of this study was to determine the presence of MRSH in different groups of companion animals and to characterize isolates according the...
López C, Alvarez ME, Carmona JU.The aims were (1) to evaluate the bacteriostatic effect of platelet-rich plasma (PRP), platelet-rich gel (PRG), leukocyte-poor plasma (LPP), leukocyte-poor gel (LPG), plasma, and heat-inactivated plasma (IP) on both methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) over a period of 24 h; (2) to determine and to compare the concentrations and degradation over time of platelet factor 4 (PF-4), transforming growth factor beta 1 (TGF-β 1), and platelet-derived growth factor isoform BB (PDGF-BB); and (3) to identify any correlations between...
Rebordão MR, Galvão A, Szóstek A, Amaral A, Mateus L, Skarzynski DJ, Ferreira-Dias G.Endometrosis is a degenerative chronic process, characterized by paramount fibrosis development in mare endometrium. This condition is one of the major causes of subfertility/infertility in mares. As in other organs, fibrosis might be a pathologic sequel of many chronic inflammatory diseases. However, aetiology and physiopathologic mechanisms involved in endometrial fibrosis are still controversial. This review presents new hypotheses based on our newest data. As the first line of innate immune defence, systemic neutrophils arrive in the uterus at mating or in the presence of pathogens. A nove...
Rebordão MR, Carneiro C, Alexandre-Pires G, Brito P, Pereira C, Nunes T, Galvão A, Leitão A, Vilela C, Ferreira-Dias G.Besides the classical functions, neutrophils (PMNs) are able to release DNA in response to infectious stimuli, forming neutrophil extracellular traps (NETs) and killing pathogens. The pathogenesis of endometritis in the mare is not completely understood. The aim was to evaluate the in vitro capacity of equine PMNs to secrete NETs by chemical activation, or stimulated with Streptococcus equi subspecies zooepidemicus (Szoo), Escherichia coli (Ecoli) or Staphylococcus capitis (Scap) strains obtained from mares with endometritis. Ex vivo endometrial mucus from mares with bacterial endometritis wer...
Bergström K, Grönlund U.Detection of nosocomial methicillin-resistant Staphylococcus aureus infections in horses in Sweden has increased attention on infection control (IC) in equine hospitals. This study established baseline data on IC programmes within such settings, evaluated compliance with some IC procedures before and after an education intervention, and examined barriers to compliance.The study was carried out between 2008 and 2011 in four Swedish equine hospitals. Data on current IC of each hospital, purchase data on hand sanitisers and disposable gloves per patient, and direct observations of compliance with...
Gharsa H, Slama KB, Gómez-Sanz E, Gómez P, Klibi N, Zarazaga M, Boudabous A, Torres C.Staphylococcus intermedius group (SIG) bacteria can colonise the nares of some animals but are also emerging pathogens in humans and animals. Objective: To analyse SIG nasal carriage in healthy donkeys destined for food consumption in Tunisia and to characterise recovered isolates. Methods: Nasal swabs from 100 healthy donkeys were tested for SIG recovery, and isolates were identified by biochemical and molecular methods. Antimicrobial susceptibility of isolates was tested and detection of antimicrobial resistance and virulence genes was performed. Isolates were typed at the clonal level by mu...
Laverty G, McCloskey AP, Gilmore BF, Jones DS, Zhou J, Xu B.Self-assembling dipeptides conjugated to naphthalene show considerable promise as nanomaterial structures, biomaterials, and drug delivery devices. Biomaterial infections are responsible for high rates of patient mortality and morbidity. The presence of biofilm bacteria, which thrive on implant surfaces, are a huge burden on healthcare budgets, as they are highly resistant to current therapeutic strategies. Ultrashort cationic self-assembled peptides represent a highly innovative and cost-effective strategy to form antibacterial nanomaterials. Lysine conjugated variants display the greatest po...
López C, Carmona JU, Giraldo CE, Alvarez ME.1) To evaluate the bacteriostatic in vitro effect of pure platelet-rich plasma (P-PRP), pure platelet-rich gel (P-PRG), leukocyte-poor gel (LPG), platelet-poor plasma (PPP), and heat inactivated plasma (IP) against methicillin-sensitive Staphylococcus aureus (MSSA) over a period of 24 hours. 2) To determine the degradation of platelet factor-4 (PF-4), transforming growth factor beta 1 (TGF-β1), and platelet-derived growth factor isoform BB (PDGF-BB) in these equine blood components. 3) To establish correlations between platelet and leukocyte counts, PF-4 concentrations, and MSSA growth. Metho...
Kelmer G, Tatz AJ, Famini S, Bdolah-Abram T, Soback S, Britzi M.Regional limb perfusion (RLP) significantly decreases morbidity and mortality associated with distal limb injuries in horses. There is an urgent need for finding additional effective antimicrobial drugs for use in RLP. In this study, we tested the pharmacokinetics (PK) of chloramphenicol in RLP. Eight horses participated in the study, which was approved by the University Animal Care and Use Committee. The cephalic and the saphenous veins were used to perfuse the limbs. Synovial samples were collected from the metacarpo/metatarsophalangeal (MCP/MTP) joint. The Friedman Test was applied for asse...
Skärlina EM, Wilmink JM, Fall N, Gorvy DA.The success of primary healing of equine traumatic wounds is dependent on thorough debridement. A specific hydrosurgical debridement device (Versajet(TM) )(a) is gentle to viable tissues, yet effectively removes macroscopic contaminants and debris. We wished to investigate whether it is effective in reducing bacterial burden and whether it differs from traditional methods. No previous reports compare hydrosurgical debridement and conventional wound debridement with regard to bacterial reduction from in vitro inoculated soft tissue. Objective: To assess the effectiveness of hydrosurgical debrid...
van Balen J, Mowery J, Piraino-Sandoval M, Nava-Hoet RC, Kohn C, Hoet AE.The role that environmental contamination might play as a reservoir and a possible source of Methicillin-resistant Staphylococcus aureus (MRSA) for patients and personnel at equine veterinary hospitals remains undefined, as the environment has only been monitored during outbreaks or for short periods. Therefore, the objectives of this study were to determine the monthly presence, distribution, and characteristics of environmental MRSA at an equine hospital, and to establish patterns of contamination over time using molecular epidemiological analyses. For this purpose, a yearlong active MRSA su...
Abdelbary MM, Wittenberg A, Cuny C, Layer F, Kurt K, Wieler LH, Walther B, Skov R, Larsen J, Hasman H, Fitzgerald JR, Smith TC, Wagenaar JA....In the early 2000s, a particular MRSA clonal complex (CC398) was found mainly in pigs and pig farmers in Europe. Since then, CC398 has been detected among a wide variety of animal species worldwide. We investigated the population structure of CC398 through mutation discovery at 97 genetic housekeeping loci, which are distributed along the CC398 chromosome within 195 CC398 isolates, collected from various countries and host species, including humans. Most of the isolates in this collection were received from collaborating microbiologists, who had preserved them over years. We discovered 96 bi-a...
Zantingh AJ, Schwark WS, Fubini SL, Watts AE.To determine the effect of regional limb perfusion (RLP) with amikacin sulfate alone and in combination with ticarcillin/clavulanate on synovial fluid concentration and antimicrobial activity of amikacin. Methods: Experimental study. Methods: RLP with amikacin alone (A; 2.5 g) or amikacin and ticarcillin/clavulanate (AT; 2.5 g amikacin, 7 g ticarcillin/clavulanate) was performed with a tourniquet placed at mid-antebrachium in standing, sedated horses. Perfusate blood was collected immediately after injection and again before tourniquet release. Blood from the jugular vein was collected before ...
Vincze S, Stamm I, Kopp PA, Hermes J, Adlhoch C, Semmler T, Wieler LH, Lübke-Becker A, Walther B.Staphylococcus (S.) aureus is an important cause of wound infections in companion animals, and infections with methicillin-resistant S. aureus (MRSA) are of particular concern due to limited treatment options and their zoonotic potential. However, comparable epidemiological data on MRSA infections in dogs, cats and horses is scarce, also limiting the knowledge about possible links to MRSA isolates from human populations. To gain more knowledge about the occurrence and genotypic variation of MRSA among wound swabs of companion animal origin in Germany we performed a survey (2010-2012) including...
Schlusselhuber M, Guldbech K, Sevin C, Leippe M, Petry S, Grötzinger J, Giguère S, Cauchard J.The equine antimicrobial peptide eCATH1 previously has been shown to have in vitro activity against antibiotic-susceptible reference strains of Rhodococcus equi and common respiratory bacterial pathogens of foals. Interestingly, eCATH1 was also found to be effective in the treatment of R. equi infection induced in mice. The aim of this study was to assess the in vitro activity of eCATH1 against equine isolates of Gram-negative (Escherichia coli, Salmonella enterica, Klebsiella pneumoniae and Pseudomonas spp.) and Gram-positive (R. equi, Staphylococcus aureus) bacteria resistant to multiple cla...
Loncaric I, Künzel F, Licka T, Simhofer H, Spergser J, Rosengarten R.The aim of this study was to investigate the antimicrobial resistance, resistance gene patterns and genetic relatedness of a collection of Austrian methicillin-resistant Staphylococcus aureus (MRSA) isolates from companion animals and horses. A total of 89 non-repetitive MRSA isolates collected during routine veterinary microbiological examinations from April 2004 to the end of 2012, and one isolate from 2013 were used for this study. The presence of mecA and other resistance genes was confirmed by PCR. Isolates were genotyped by spa typing, two multiple-locus variable-number tandem repeat ana...
Akridge HD, Rankin SC, Griffeth GC, Boston RC, Callori NE, Morris DO.Meticillin-resistant Staphylococcus aureus (MRSA) strain USA 500 predominately colonizes horses and people working with them. Previous studies demonstrate that some Staphylococcus species exhibit higher affinity for corneocytes of specific mammalian species. Objective: The objective was to determine the relative affinities of various MRSA strains, meticillin-susceptible S. aureus (MSSA) strains and a meticillin-susceptible Staphylococcus pseudintermedius (MSSP) for equine corneocytes. We hypothesized that MRSA strain USA 500 would exhibit greater adhesion than other staphylococcal strains te...
Carnwath R, Graham EM, Reynolds K, Pollock PJ.Delayed healing associated with distal limb wounds is a particular problem in equine clinical practice. Recent studies in human beings and other species have demonstrated the beneficial wound healing properties of honey, and medical grade honey dressings are available commercially in equine practice. Equine clinicians are reported to source other non-medical grade honeys for the same purpose. This study aimed to assess the antimicrobial activity of a number of honey types against common equine wound bacterial pathogens. Twenty-nine honey products were sourced, including gamma-irradiated and no...
Watts AE, Fubini SL, Vernier-Singer M, Golkowski C, Shin S, Todhunter RJ.To determine the effect of nonthermal plasma on Staphylococcus aureus, fibroblasts in monolayer culture, and clean and contaminated skin explants. Methods: Normal skin from euthanized horses. Methods: S aureus organisms were plated and treated with nonthermal plasma followed by bacterial culture to assess viability. Fibroblasts in monolayer culture and the epidermal and dermal surfaces of clean and S aureus-contaminated skin explants were treated. The effects of distance and duration on the response to treatment were compared. Results: Compared with controls, treatment with nonthermal plasma r...
Schlusselhuber M, Guldbech K, Sevin C, Leippe M, Petry S, Grötzinger J, Giguère S, Cauchard J.The equine antimicrobial peptide eCATH1 previously has been shown to have in vitro activity against antibiotic-susceptible reference strains of Rhodococcus equi and common respiratory bacterial pathogens of foals. Interestingly, eCATH1 was also found to be effective in the treatment of R. equi infection induced in mice. The aim of this study was to assess the in vitro activity of eCATH1 against equine isolates of Gram-negative (Escherichia coli, Salmonella enterica, Klebsiella pneumoniae and Pseudomonas spp.) and Gram-positive (R. equi, Staphylococcus aureus) bacteria resistant to multiple cla...
Deniaud M, Tee E.Corneal ulceration is a common ophthalmic condition in horses. It is frequently caused by trauma to the corneal surface, followed by secondary infection by commensal or pathogenic organisms including Streptococcus equi subspecies zooepidemicus, Pseudomonas aeruginosa and Staphylococcus spp. Emerging antimicrobial resistance amongst these organisms has raised the need for appropriate antimicrobial therapy selection, to optimise treatment efficacy while minimising further antimicrobial resistance. Medical records of 38 horses presented at the University Veterinary Teaching Hospital Camden for ul...
Lisboa FP, Silvestre WP, Castro JO, Martins GV, Segabinazzi LGTM, Pauletti GF, Dell'Aqua JA.This study aimed to evaluate the in vitro antimicrobial activity of essential oils (EO) from Ocimum basilicum (basil), Rosmarinus officinalis (rosemary), and Cymbopogon citratus (lemongrass) on endometritis-causing microorganisms in mares. Serial concentrations of the EO from 30.00 mg/mL to 0.47 mg/mL were tested. The major compounds of O. basilicum EO were linalyl acetate (33.32 wt.%) and citronellal (25.06 wt.%); of R. officinalis EO were borneol (26.48 wt.%), trans-β-ocimene (16.76 wt.%), camphene (12.45 wt.%), and α-phellandrene (11.08 wt.%); and of C. citratus EO were geranial (45.96 ...
Khairullah AR, Sudjarwo SA, Effendi MH, Ramandinianto SC, Widodo A, Riwu KHP.Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) was first discovered in horses in 1989. Since then, LA-MRSA has begun to be considered an important strain of pathogenic bacteria in horses, which can cause LA-MRSA infection and colonization in humans with public health impacts. The anterior nares are the primary site of LA-MRSA colonization in horses, although LA-MRSA colonization may also occur in the gastrointestinal tract in horses. LA-MRSA-infected horses typically exhibit clinical infection or may not exhibit clinical infection. There are two potential risks asso...
Kelmer G, Tatz AJ, Famini S, Bdolah-Abram T, Soback S, Britzi M.Regional limb perfusion (RLP) significantly decreases morbidity and mortality associated with distal limb injuries in horses. There is an urgent need for finding additional effective antimicrobial drugs for use in RLP. In this study, we tested the pharmacokinetics (PK) of chloramphenicol in RLP. Eight horses participated in the study, which was approved by the University Animal Care and Use Committee. The cephalic and the saphenous veins were used to perfuse the limbs. Synovial samples were collected from the metacarpo/metatarsophalangeal (MCP/MTP) joint. The Friedman Test was applied for asse...
Colbath AC, Wittenburg LA, Gold JR, McIlwraith CW, Moorman VJ.To determine the effect of intravenous regional limb perfusion (IVRLP) with a combination of mepivacaine hydrochloride and amikacin sulfate on synovial fluid amikacin sulfate concentration, antimicrobial activity, and mechanical nociceptive threshold (MNT). Methods: Experimental study. Methods: Healthy adult horses (n=9). Methods: One IVRLP treatment was randomly administered by cephalic vein of each limb: amikacin alone (1 g amikacin in 60 mL saline) or amikacin with mepivacaine (1 g amikacin and 500 mg mepivacaine in 60 mL saline). Opposite treatments were repeated after a 24 hour wash-out p...
Marshall K, Marsella R.Increased antimicrobial resistance highlights the need for alternatives to antibiotics. Bacteriophages, which are benign viruses that kill bacteria, are promising. We studied the efficacy of topical bacteriophages for treating equine staphylococcal superficial pyodermas. Eight isolates were tested against a bacteriophage bank, and a cocktail consisting of two bacteriophages was prepared. Twenty horses with clinical and cytological evidence of superficial pyoderma and confirmed infection based on swabbed culture were enrolled in the study. Each horse received both the bacteriophage cocktail a...
Orsini JA, Snooks-Parsons C, Stine L, Haddock M, Ramberg CF, Benson CE, Nunamaker DM.We retrospectively reviewed the cases of 15 foals and adult horses in which vancomycin was used, alone or in combination with an aminoglycoside, to treat methicillin-resistant staphylococcal and enterococcal infections. Signalment, presenting complaint, history (including history of treatment for the current complaint), results of bacterial culture and antimicrobial susceptibility testing, treatment, and outcome were reviewed. The average vancomycin dosage was 7.5 mg/kg q8h, administered by intravenous infusion over 30 min. The infection resolved in all 7 horses with soft tissue infections and...
Rynhoud H, Meler E, Gibson JS, Price R, Maguire T, Farry T, Bennett E, Hartono J, Soares Magalhães RJ.To detect methicillin resistant Staphylococcus aureus (MRSA) and S. pseudintermedius (MRSP) swab samples were collected from dogs, cats and horses from South East Queensland (SE QLD). MRSP carriage in dogs was 8.7% and no MRSP was isolated from cats and horses; no MRSA was isolated. Risk factors for carriage included previous hospitalisation, previous bacterial infection, consultation type, average precipitation, and human population density. The probability of MRSP carriage was highest in Brisbane city, Sunshine Coast and Gympie. This suggests that MRSP carriage in dog populations from SE QLD...
Brown MP, Gronwall R, Castro L.Six healthy adult mares were each given a single IV injection of trimethoprim (TMP)-sulfamethoxazole (SMZ) at a dosage of 2.5 mg of TMP/kg of body weight and 12.5 mg of SMZ/kg. Serum concentrations of each drug were measured serially over a 24-hour period. For TMP, the mean overall elimination rate constant (K) was 0.43/hr and the elimination half-life (t1/2) was 1.9 hours. The apparent volume of distribution (at steady state) was 1.62 L/kg and TMP clearance was 886 ml/hr/kg. For SMZ, K was 0.22/hr and t1/2 was 3.53 hours. The apparent volume of distribution at steady state was 0.33 L/kg and S...
Kuroda T, Minamijima Y, Niwa H, Tamura N, Mita H, Fukuda K, Kaimachi M, Suzuki Y, Enoki Y, Taguchi K, Matsumoto K, Toutain PL, Bousquet-Melou A....First-generation cephalosporins have good activity against gram-positive bacteria and are extensively used in horses. There are few reports of pharmacokinetics and pharmacodynamics (PK/PD) analysis of cephalosporins in horses. Objective: To optimise the dosages of the two first-generation cephalosporins cephalothin (CET) and cefazolin (CEZ) in horses using PK/PD concepts. Methods: Experimental study with single administration. Methods: Drug plasma concentrations following a single intravenous (i.v.) administration of 22 mg/kg bodyweight (bwt) CET in 12 horses and of 10 mg/kg bwt CEZ in six h...
Uchida-Fujii E, Niwa H, Kanai K, Kinoshita Y, Kuroda T, Nukada T, Ueno T.Methicillin-resistant Staphylococcus aureus (MRSA) has often been isolated from livestock and companion animals, including horses. Seven cases of MRSA infection in Thoroughbred racehorses were observed in an equine hospital in Japan in 2020. In this study, MRSA isolates from these seven horses and nine veterinarians in the equine hospital were studied to examine their genetic relatedness and evaluate the possibility of MRSA transmission. The MRSA isolates were subjected to whole-genome sequencing for multi-locus sequence typing, S. aureus protein A (spa) typing, staphylococcal cassette chromos...
Waqar N, Amin Q, Munir T, Ikram MS, Shahzad N, Mirza A, Ali A, Arshad MI.The present study aimed at investigating the percent prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in equines and associated personnel. A total of 150 swabs of equines and 50 nasal swab samples of associated personnel were collected. These samples were processed in mannitol salt broth for enrichment. A total of 175 nasal swab samples changed the broth color from pink to yellow which were detected as samples containing S. aureus. These samples were processed further on specific media, namely mannitol salt agar, Staph-110, and blood agar, for phenotypic and Gram's staining-bas...
Wolny-Koładka K.The aim of this study was to assess the microbiological quality of air in three horse riding centers differing in the horse keeping systems. The air samples were collected in one facility with free-range horse keeping system and two with box stalls of different sizes. The samples were collected over a period of 3 years (2015-2017), four times per year (spring, summer, autumn, winter) to assess the effect of seasonal changes. The prevalence of aerobic mesophilic bacteria, mold fungi, actinomycetes, Staphylococcus spp., and Escherichia coli was determined by the air collision method on Petri di...
Anderson ME, Weese JS.Screening for nasal colonization is an important aspect of many methicillin-resistant Staphylococcus aureus (MRSA) control programs. Real-time polymerase chain reaction (RT-PCR) is an attractive alternative to standard culture techniques because of the considerably shorter turnaround time. An assay has been validated for diagnostic purposes in humans, however this methodology has not been evaluated in horses. The purpose of this study was to compare an RT-PCR assay for rapid identification of MRSA directly from nasal swabs in horses to standard culture techniques. Nasal swabs collected from 29...
Gustafson SB, McIlwraith CW, Jones RL.Four groups of 8 horses each had 1 midcarpal joint injected with 33 colony-forming units (CFU) of viable Staphylococcus aureus plus: 1 ml of saline solution (group 1, control), 250 mg of polysulfated glycosaminoglycan (PSGAG, group 2), 100 mg of methylprednisolone acetate (group 3), or 20 mg of sodium hyaulronate (group 4). Horses were euthanatized, and samples were obtained on the basis of clinical signs of septic arthritis that were nonresponsive to phenylbutazone administration. One group-1 horse, all 8 group-2 horses, 3 group-3 horses, and 4 group-4 horses were culture-positive for S aureu...
Haspeslagh M, Van Hecke LL, Hermans K, Chiers K, Pint E, Wilmink JM, Martens AM.Distal limb wounds in horses often show aberrant healing due to a slow inflammatory response. In human medicine, negative pressure wound therapy (NPWT) is used for the treatment of chronic wounds with a similar inflammatory response. Objective: To compare the effect of NPWT to calcium alginate dressings on the healing of (non) contaminated equine distal limb wounds. Methods: Controlled experiment. Methods: Circular wounds were created on the left and right dorsomedial metacarpus of 10 horses. In five horses, the wounds were contaminated with Staphylococcus aureus and Pseudomonas aeruginosa. In...
Mota SL, Dos Santos LO, Vidaletti MR, Rodrigues RO, Coppola MM, Mayer FQ.Antimicrobial resistance (AMR) is a global concern that must be addressed from a one health perspective. Horses are companion animals and their contact with humans facilitates exchange of resistant bacteria. This study aimed to evaluate AMR of coagulase-positive Staphylococcus (CoPS), including Staphylococcus aureus, isolated from healthy Crioulo horses. Swab samples from nostrils (n = 214) and skin (n = 107) of 107 horses from Porto Alegre, South Brazil, were used for CoPS isolation. The isolates were evaluated for AMR and a multivariate logistic regression was applied to identify the ris...
Zak A, Siwinska N, Slowikowska M, Borowicz H, Ploneczka-Janeczko K, Chorbinski P, Niedzwiedz A.Commensal bacterial and fungal flora of the conjunctival sac has been described in horses and other animals. The identification of commensal flora of the conjunctival sac may aid in the diagnosis of ocular inflammatory diseases, such as conjunctivitis or more severe ulcerative keratitis, common in horses. Moreover, damage of ocular protective barriers may lead to an opportunistic infection. The study was carried out in Silesian horses kept at a single breeding center in South-western Poland, in order to limit any breed-dependant and climate-dependant variables affecting the results. Following ...
Kuroda T, Kinoshita Y, Niwa H, Mizobe F, Ueno T, Kuwano A, Hatazoe T, Hobo S.We report the first case of methicillin-resistant Staphylococcus aureus (MRSA) keratitis in a racehorse. A 5-year-old mare developed punctate keratitis after racing. The corneal ulcer continued to expand despite ophthalmic antimicrobial therapy. On day 6, a conjunctival graft surgery was performed. The mare was euthanized, following colitis and laminitis development on day 10. MRSA was isolated from the corneal swab taken at the time of euthanasia. Immunohistochemical analysis demonstrated gram-positive and anti-S. aureus monoclonal antibody-positive cocci infiltration of the corneal stroma; a...
Kelmer G, Tatz AJ, Kdoshim E, Britzi M, Segev G.This prospective experimental study goal was to determine the pharmacokinetics of imipenem after intravenous regional limb perfusion (IV-RLP) in standing horses. Nine horses participated in the study; that was approved by the University Animal Care and Use Committee. One thoracic limb or one pelvic limb of each horse was randomly selected. After the veins were catheterized, an Esmarch bandage tourniquet was applied and the catheter was injected with a solution containing 500mg of imipenem. Synovial fluid samples were collected from the fetlock joint and blood samples were collected from the ju...
Tulamo RM, Bramlage LR, Gabel AA.Infectious arthritis was induced experimentally in one tarsocrural joint of six horses by intra-articular injection of 1 ml Staphylococcus aureus-saline suspension with the addition of 200 mg methylprednisolone acetate. The corresponding contralateral joint was injected with 1 ml of saline with the addition of 200 mg methylprednisolone acetate, and served as a control. The purpose of the experiment was to examine the effect of corticosteroids on the acute clinical signs of infectious arthritis, and the associated changes in synovial fluid, to separate the effects of a steroid injection from th...
Cattabiani F, Cabassi E, Allodi C, Gianelli F.The AA. report the results of taxonomic research conducted on the conjunctival sac of 59 horses for identification of the present bacterial flora. In the controlled animals, it was observed, at the level of the considered niche, a community constituted of normal bacterial populations, but not autochtonous in the significance they attributed from DUBOS et al., relative to the characterization of the indigenous microbiota of the intestine. The isolated normal bacterial flora seems to be constituted of: Micrococcus (subgroup 6 of Baird-Parker, M. luteus, Micrococcus spp.) isolated in 49,15% of th...
Boyen F, Smet A, Hermans K, Butaye P, Martens A, Martel A, Haesebrouck F.The use of β-lactam antibiotics results in the selection of bacteria showing resistance toward this class of antibiotics. The review focuses on the increasing importance of methicillin resistant staphylococci and broad-spectrum β-lactamase-producing Enterobacteriaceae in horses. Diagnostic protocols that optimize accurate identification of these bacteria from both clinical samples and samples obtained from putative carrier animals are described. In addition, the opportunities and pitfalls for preventive and curative measures are discussed.
Anwaar F, Ijaz M, Rasheed H, Shah SFA, Haider SAR, Sabir MJ.The purpose of the current study was to investigate the nasal colonization and drug resistance profile of Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), and vancomycin-resistant S. aureus (VRSA) in donkeys (n =63), mules (n = 42), and horses (n = 98). MRSA and VRSA were confirmed based on phenotypic and molecular methods, followed by phylogenetic analysis. Furthermore, the association of various animal and management-based risk factors with S. aureus colonization was also evaluated. The presence of nuc gene on polymerase chain reaction showed an overall prevalence of 42.86%...
Couto N, Belas A, Tilley P, Couto I, Gama LT, Kadlec K, Schwarz S, Pomba C.The aim of this study was to evaluate the biocide and antimicrobial susceptibility of methicillin-resistant staphylococcal isolates from horses. Fourteen methicillin-resistant staphylococci (MRS) were subjected to an extensive genotype characterization, including SCCmec, dru, spa, PFGE and MLST typing. Antimicrobial susceptibility testing was performed and resistance genes were detected by PCR. Minimum bactericidal concentrations (MBCs) of four biocides [chlorhexidine acetate (CHA), benzalkonium chloride (BAC), triclosan (TCL) and glutaraldehyde (GLA)] were determined following the recommendat...
