Topic:Antimicrobial
Antimicrobials are agents used to inhibit the growth of or destroy microorganisms, including bacteria, viruses, fungi, and parasites, in horses. They are employed in the treatment and prevention of infections and play a role in maintaining equine health. Antimicrobials can be classified into various categories, such as antibiotics, antifungals, antivirals, and antiparasitics, each targeting specific types of pathogens. The use of antimicrobials in horses is subject to considerations regarding dosage, administration routes, and potential resistance development. This page compiles peer-reviewed research studies and scholarly articles that explore the application, efficacy, and challenges associated with antimicrobial use in equine medicine.
Pharmacokinetic-pharmacodynamic cutoff values for benzylpenicillin in horses to support the establishment of clinical breakpoints for benzylpenicillin antimicrobial susceptibility testing in horses. The aim of this international project was to establish a species-specific Clinical Breakpoint for interpretation of Antimicrobial Susceptibility Testing of benzylpenicillin (BP) in horses. Unassigned: A population pharmacokinetic model of BP disposition was developed to compute PK/PD cutoff values of BP for different formulations that are commonly used in equine medicine around the world (France, Sweden, USA and Japan). Investigated substances were potassium BP, sodium BP, procaine BP, a combination of procaine BP and benzathine BP and penethamate, a prodrug of BP. Data were collected from 40 ...
Detection and genomic characterization of a multidrug-resistant Salmonella Newport co-harbouring blaCMY-2, qnrB19 and mcr-9 from the diarrheic faeces of a foal. This study reports the genomic characterization of the multidrug resistant Salmonella Newport strain 195_20 recovered from the diarrheic faeces of a foal in Brazil and co-harbouring the mcr-9, blaCMY-2 and qnrB19 antibiotic resistance genes. Bacterial isolate positive for mobile colistin resistance gene (mcr-9) was submitted to antimicrobial susceptibility testing by disk diffusion and broth microdilution for colistin and polymyxin B. The isolate was submitted to whole genome sequencing by Illumina technology and Nanopore Sequencing. Conjugation assays, plasmid sizes determined by S1-PFGE and ...
Discrepancies between phenotypic and genotypic identification methods of antibiotic resistant genes harboring Staphylococcusaureus. Antimicrobial resistance is a global issue that limits therapeutic options for infections. S. aureus being a member of the ESKAPE group is capable of "escaping" the biocidal action of antimicrobial agents. There are phenotypic and genotypic methods used for the identification of antibiotic resistant genes harboring S. aureus but these methods do not always show concordant results. To address these discrepancies, a total of 335 equine nasal swab samples from four districts of Punjab were collected using a convenient sampling technique. These samples were first subjected to common microbial tech...
Antimicrobial Activity of Milk Whey in Different Mammals. Antimicrobial activity of milk whey in different mammals against Candida albicans yeast cells was studied by a spectrophotometric method. The activity increased in the order goat→horse→camel→cow→human→mouse. The level of whey activity in mice was higher by 3 and 10 times than in humans and goats, respectively. Similar changes were noted for activity of the whey fraction <100 kDa containing a complex of antimicrobial polypeptides, and there was a direct correlation between these two parameters (r=0.881; p<0.05). The total activity of whey had a high degree of correlation with th...
Preliminary Investigation of Side Effects of Polymyxin B Administration in Hospitalized Horses. Neuro- and nephrotoxicity of polymyxins are known but clinical studies in horses are lacking. The aim of this study was to describe neurogenic and nephrogenic side effects of hospitalized horses receiving Polymyxin B (PolyB) as part of their treatment plan. Twenty horses diagnosed with surgical colic ( = 11), peritonitis ( = 5), typhlocolitis ( = 2), pneumonia, and pyometra (each = 1) were included. Antimicrobial treatment was randomized to GENTA (gentamicin 10 mg/kg bwt q24 h IV, penicillin 30.000 IU/kg q6 h IV) or NO GENTA (marbofloxacin 2 mg/kg bwt q24 h IV, penicillin 30.000 IU/kg q6 h IV...
Basic Postoperative Care of the Equine Colic Patient. The 3 time periods around colic surgery (preoperative, operative, and postoperative) are all critical to successful outcomes. Although much focus is often paid to the first 2 time periods, the importance of sound clinical judgment and rational decision-making in the postoperative period cannot be overstated. This article will outline the basic principles of monitoring, fluid therapy, antimicrobial therapy, analgesia, nutrition, and other therapeutics routinely used in patients following colic surgery. Discussions of the economics of colic surgery and expectations for normal return to function ...
Administration safety of medical-grade honey (MGH) in septic synovial structures in horses: 3 cases. The objective of this study was to investigate the postoperative use of intrasynovial honey as an antimicrobial after treatment for synovial sepsis in horses. One colt and 2 mares were presented with acute lameness, with or without an associated wound. All 3 cases were initially managed with surgical endoscopic or tenoscopic debridement and lavage for treatment of different synovial structures. Collection of synovial fluid was consistent with synovial sepsis and this was diagnosed in each case. All horses subsequently underwent arthroscopic lavage under general anesthetic and intraarticular or...
Corynebacteria of the diphtheriae Species Complex in Companion Animals: Clinical and Microbiological Characterization of 64 Cases from France. Corynebacteria of the diphtheriae species complex (CdSC) can cause diphtheria in humans and have been reported from companion animals. We aimed to describe animal infection cases caused by CdSC isolates. A total of 18,308 animals (dogs, cats, horses, and small mammals) with rhinitis, dermatitis, nonhealing wounds, and otitis were sampled in metropolitan France (August 2019 to August 2021). Data on symptoms, age, breed, and the administrative region of origin were collected. Cultured bacteria were analyzed for tox gene presence, production of the diphtheria toxin, and antimicrobial susceptibili...
Identification of putative orthologs of clinically relevant antimicrobial peptides in the equine ocular surface and amniotic membrane. This study aimed to define the antimicrobial peptide (AMP) expression pattern of the equine ocular surface and amniotic membrane using a targeted qPCR approach and 3'Tag-sequencing. It will serve as a reference for future studies of ocular surface innate immunity and amniotic membrane therapies. Methods: A targeted qPCR approach was used to investigate the presence of orthologs for three of the most highly expressed beta-defensins (DEFB1, DEFB4B, and DEFB103A) of the human ocular surface and amniotic membrane in equine corneal epithelium, conjunctiva, and amniotic membrane. 3'Tag-sequencing wa...
The concentration of lidocaine and mepivacaine measured in synovial fluid of different joints of horses after single intra-articular injection. To determine the synovial fluid (SF) concentrations of lidocaine and mepivacaine after intra-articular injection with clinically relevant doses to the distal interphalangeal (DIP), metacarpophalangeal (MCP), middle carpal (MC), and tarsocrural (TC) joint at two different time points after injection in order to be able to compare concentrations with previously established concentrations associated with cytotoxicity and antimicrobial activity. Unassigned: In the first of two experiments, 20 joints (5 MC, 5 MCP, 10 DIP joints) of five horses under general anesthesia were injected with clinically ...
A Systematic Review of the Bioactive Components, Nutritional Qualities and Potential Therapeutic Applications of Donkey Milk. In addition to providing individualized, specific, and ample nutritional compounds, donkey milk (DM) offers immunological modulation during health and disease. Recently, DM has attracted major interest in preparing infant formulas due to its similarity to human milk in terms of high protein and lactose content and low-fat concentration. The antimicrobial, anti-inflammation, antioxidant, and hypo-allergenicity properties of DM in human infants are well-documented. The purpose of this review is to summarize the knowledge of studies done in characterizing the composition of DM, including bioactiv...
A Descriptive Study of the Clinical Presentation, Management, and Outcome of Horses with Acute Soft Tissue Trauma of the Tarsus and the Association with Synovial Involvement. The tarsus is one of the most common areas of traumatic injury with associated synovial involvement (SI) in horses. The aim of this retrospective study was to describe the clinical presentation, diagnostic procedures, management (emphasizing the type, duration, and route of antimicrobial administration), and outcome of cases with acute soft tissue trauma to the tarsal region. The presenting clinical features, the results of diagnostic modalities, and the initial response to therapy were assessed for their usefulness to predict SI. Medical records of 72 cases were included and SI was diagnosed ...
Streptococcus equi culture prevalence, associated risk factors and antimicrobial susceptibility in a horse population from Colombia. The objectives of this study were to determine the prevalence of S. equi in a horse population in Colombia, to determine the risk factors associated with its detection in the guttural pouches and to report the antimicrobial susceptibility of the isolates. Fifteen farms and 137 horses >6 months of age were enrolled. Sampling was randomly, stratified and proportional to the population size of each farm. The guttural pouch (GP) was swabbed via endoscopic guidance and culture was performed. DNA extraction and conventional PCR were performed in colonies compatibles with S. equi, the PCR products we...
In Vitro Antimicrobial Activity of Selected Essential Oils Against Endometritis-Causing Microorganisms in Mares. 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 ...
Biofilm and Equine Limb Wounds. In chronic wounds in humans, biofilm formation and wound chronicity are linked, as biofilms contribute to chronic inflammation and delayed healing. Biofilms are aggregates of bacteria, and living as biofilms is the default mode of bacterial life; within these aggregates, the bacteria are protected from both antimicrobial substances and the immune response of the host. In horses, delayed healing is more commonly seen in limb wounds than body wounds. Chronic inflammation and hypoxia are the main characteristics of delayed wound healing in equine limbs, and biofilms might also contribute to this ...
[Development of fermented milk product based on mare milk and lactic microorganisms association]. Since ancient times, mare's milk has been widely used by many peoples. Thanks to its unique composition, it is now used in the nutrition of people with allergies to cow's milk, in the technologies of foods for special dietary uses, etc. To expand the range of products with useful properties, it is advisable to develop fermented milk products based on mare's milk. Numerous studies indicate that the use of fermented milk products provides various health benefits. And the use of probiotic cultures in the composition of starter cultures for fermented milk products allows you to add a number of fun...
Antimicrobial Resistance Spectrum Conferred by pRErm46 of Emerging Macrolide (Multidrug)-Resistant Rhodococcus equi. Clonal multidrug resistance recently emerged in Rhodococcus equi, complicating the therapeutic management of this difficult-to-treat animal- and human-pathogenic actinomycete. The currently spreading multidrug-resistant (MDR) "2287" clone arose in equine farms upon acquisition, and coselection by mass macrolide-rifampin therapy, of the pRErm46 plasmid carrying the (46) macrolide-lincosamide-streptogramin resistance determinant, and of an mutation. Here, we screened a collection of susceptible and macrolide-resistant strains from equine clinical cases using a panel of 15 antimicrobials agains...
Antimicrobial peptides in domestic animals and their applications in veterinary medicine. Antimicrobial peptides (AMPs) are molecules with a broad-spectrum activity against bacteria, fungi, protozoa, and viruses. These peptides are widely distributed in insects, amphibians and mammals. Indeed, they are key molecules of the innate immune system with remarkable antimicrobial and immunomodulatory activity. Besides, these peptides have also shown regulatory activity for gut microbiota and have been considered inductors of growth performance. The current review describes the updated findings of antimicrobial peptides in domestic animals, such as bovines, goats, sheep, pigs, horses, cani...
In vitro antimicrobial activity of selected essential oils against bacteria and yeasts isolated from the genital tract of mares. The aim of the present study, the first to test clinical equine isolates, was to evaluate the antimicrobial activity of commercial essential oils (EOs) obtained from and against spp., spp., and spp. previously isolated from uteri of mares with reproductive disorders. showed the best antibacterial activity against all the selected agents, with MICs ranging from 0.07 mg/mL for subsp. to 0.29 mg/mL versus sp. and spp. isolates and versus and spp., with MICs of 0.46 mg/mL and 1.86 mg/mL, respectively. EOs showed good antibacterial activity with MICs ranging from 0.07 mg/mL ...
Prevalence and performance effects of neonatal disease in Thoroughbred and Standardbred foals in South-Eastern Australia. There is little information on foal mortality and the epidemiology of diseases in the neonatal period in Australian equine breeding enterprises. Methods: This was a prospective cohort study of 1219 foals on 15 breeding farms in south-eastern Australia to identify the proportion of foals recognised on farm as abnormal at birth or within the first 48 h postpartum, determine the prevalence and risk factors for neonatal disease and assess the subsequent performance of foals in the study population. Results: Overall, 27 foals died within 6 weeks of birth in the study population (2.2%), 142 foal...
The In Vitro Effect of Ozone Therapy Against Equine Pythium insidiosum. The goal of the present study was to characterize the antimicrobial action of different ozone (O) presentations against Pythium insidiosum isolated from horses. In experiment 1, P. insidiosum was treated with ozonated distilled water, ozonated sunflower oils with distinct peroxide indexes or O gas (72 μg O mL). In experiment 2, samples were exposed one or three times to oxygen (O) or O gas (72 μg O mL; 30 min/day). In experiment 3, P. insidiosum was treated with different concentrations of O gas (Ø, 32, 52, or 72 μg O mL) for three days (30 min/day). In experiment 4, samples were ex...
Newly isolated lytic bacteriophages for Staphylococcus intermedius, structurally and functionally stabilized in a hydroxyethylcellulose gel containing choline geranate: Potential for transdermal permeation in veterinary phage therapy. In the present research work, we propose a new antimicrobial treatment for pyoderma via cutaneous permeation of bacteriophage particles conveyed in a hydroxyethylcellulose (HEC) gel integrating ionic liquid as a permeation enhancer. Ionic liquids are highly viscous fluids constituted exclusively by ions, that are usually hydrolytically stable and promote solubilization of amphipathic molecules such as proteins, hence serving as green solvents and promoting the transdermal permeation of biomolecules. In the research effort entertained herein, the synthesis and use of choline geranate for integr...
Determination of the pharmacokinetic-pharmacodynamic cut-off values of marbofloxacin in horses to support the establishment of a clinical breakpoint for antimicrobial susceptibility testing. Marbofloxacin (MBX), a fluoroquinolone (FQ), is considered as a critical antibiotic requiring antimicrobial susceptibility testing (AST) for prudent use. No clinical breakpoint (CBP) currently exists to interpret the results of such tests in horses. Objective: To compute PK/PD cut-offs (PK/PDCO ) that is one of the three minimum inhibitory concentrations (MICs) considered establishing a CBP for antimicrobial susceptibility test interpretation. Methods: A meta-analysis conducted by combining five sets of previously published pharmacokinetic data, obtained in clinical and nonclinical settings. M...
Antibacterial potential of donkey’s milk disclosed by untargeted proteomics. Donkey's milk (DM) has been extensively investigated as a valuable substitute of breast milk, often suitable to manage cow's milk protein allergy in infants. DM exhibits potent inhibitory properties against numerous microbial species. Although oligosaccharides and lipids might contribute to the antimicrobial potential, the current inventory of proteins is not able to justify the low count of microorganisms generally observed in DM. The shotgun proteomic analysis of fractionated DM disclosed a set of 94 gene products, 41% of which have documented antimicrobial activity or are involved in transf...
Incidence of incisional complications after exploratory celiotomy in equids affected with enterolithiasis. This study reports the prevalence of and risk factors for incisional complications in equids after ventral midline celiotomy for enterolithiasis. This study covered the years 2008 to 2015 and included 72 equids. Enteroliths were removed from the ascending or descending colon through 1 or more enterotomies. Complications were defined as surgical site infection and/or incisional hernia formation. Follow-up by telephone questionnaire or medical records determined that 10/72 (13.9%) equids experienced complications, with 6/72 (8.3%) developing a surgical site infection and 5/72 (6.9%) a hernia. Se...
Antimicrobial-Resistant Enterococcus faecium and Enterococcus faecalis Isolated From Healthy Thoroughbred Racehorses in Japan. In this study, the occurrence of antimicrobial-resistant (AMR) enterococci was evaluated in Thoroughbred (TB) racehorses in Japan. Fecal samples were collected from 212 healthy TB racehorses at the Miho and Ritto Training Centers of the Japan Racing Association from March 2017 to August 2018. Isolation and identification were performed by enterococcus selective medium and confirmed to the species using MALDI-TOF MS. Enterococcus faecium and E. faecalis isolates were subjected to antimicrobial susceptibility test against 11 antimicrobials by minimum inhibitory concentration based on recommenda...
DNA microarray-based characterization and antimicrobial resistance phenotypes of clinical MRSA strains from animal hosts. Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of severe infections in humans and animals worldwide. Studies elucidating the population structure, staphylococcal cassette chromosome mec types, resistance phenotypes, and virulence gene profiles of animal-associated MRSA are needed to understand spread and transmission. Objective: The objective of this study was to determine 1) clonal complexes and spa types, 2) resistance phenotypes, and 3) virulence/resistance gene profiles of MRSA isolated from animals in Switzerland. Methods: We analyzed 31 presumptive MRSA isolates co...
Effect of gallium maltolate on a model of chronic, infected equine distal limb wounds. Distal limb wounds are common injuries sustained by horses and their healing is fraught with complications due to equine anatomy, prevalence of infection, and challenges associated with wound management. Gallium is a semi-metallic element that has been shown to possess antimicrobial properties and aid in wound healing in various preclinical models. The effects of Gallium have not been studied in equine wound healing. Therefore, the objective of this study was to compare healing rates between gallium-treated and untreated wounds of equine distal limbs and to demonstrate the antimicrobial effect...
Streptococcus equi subsp. equi meningitis, septicemia and subdural empyema in a child. 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...
An Alphaherpesvirus Exploits Antimicrobial β-Defensins To Initiate Respiratory Tract Infection. β-Defensins protect the respiratory tract against the myriad of microbial pathogens entering the airways with each breath. However, this potentially hostile environment is known to serve as a portal of entry for herpesviruses. The lack of suitable respiratory model systems has precluded understanding of how herpesvirus virions overcome the abundant mucosal β-defensins during host invasion. We demonstrate how a central alphaherpesvirus, equine herpesvirus type 1 (EHV1), actually exploits β-defensins to invade its host and initiate viral spread. The equine β-defensins (eBDs) eBD1, -2, and -3...