Pathogens are microorganisms, such as bacteria, viruses, fungi, and parasites, that can cause disease in horses. These microorganisms interact with the equine immune system, often leading to a range of health issues that can affect individual horses or entire populations. Pathogens can be transmitted through various routes, including direct contact, vectors, or environmental exposure. Common equine pathogens include Streptococcus equi, Equine Herpesvirus, and Strongylus vulgaris. Understanding the interactions between equine hosts and pathogens is essential for disease prevention, management, and treatment. This page compiles peer-reviewed research studies and scholarly articles that explore the identification, transmission, and impact of pathogens on equine health.
Estep LK, McClure CJ, Burkett-Cadena ND, Hassan HK, Hicks TL, Unnasch TR, Hill GE.Eastern equine encephalitis virus (EEEV) is a mosquito-borne pathogen that cycles in birds but also causes severe disease in humans and horses. We examined patterns of avian host use by vectors of EEEV in Alabama from 2001 to 2009 using blood-meal analysis of field-collected mosquitoes and avian abundance surveys. The northern cardinal (Cardinalis cardinalis) was the only preferred host (fed on significantly more than expected based on abundance) of Culiseta melanura, the enzootic vector of EEEV. Preferred hosts of Culex erraticus, a putative bridge vector of EEEV, were American robin (Turdus ...
White GS, Pickett BE, Lefkowitz EJ, Johnson AG, Ottendorfer C, Stark LM, Unnasch TR.Florida has the highest degree of endemicity for eastern equine encephalitis virus (EEEV) of any state in the United States and is the only state with year-round transmission of EEEV. To further understand the viral population dynamics in Florida, the genome sequence of six EEEV isolates from central Florida were determined. These data were used to identify the most polymorphic regions of the EEEV genome from viruses isolated in Florida. The sequence of these polymorphic regions was then determined for 18 additional Florida isolates collected in four geographically distinct regions over a 20-y...
Diab SS, Kinde H, Moore J, Shahriar MF, Odani J, Anthenill L, Songer G, Uzal FA.Clostridium perfringens type C is an important cause of enteritis and enterocolitis in foals and occasionally in adult horses. The disease is a classic enterotoxemia, and the enteric lesions and systemic effects are caused primarily by beta toxin, 1 of 2 major toxins produced by C. perfringens type C. Until now, only sporadic cases of C. perfringens type C equine enterotoxemia have been reported. We present a comprehensive description of the lesions in 8 confirmed cases of type C enterotoxemia in foals and adult horses. Grossly, multifocal to segmental hemorrhage and thickening of the intestin...
Casagrande Proietti P, Bietta A, Coppola G, Felicetti M, Cook RF, Coletti M, Marenzoni ML, Passamonti F.The objective of this manuscript was to validate published PCR-based methods for detection of β-haemolytic Streptococci by comparison with established bacteriological techniques using 85 clinical isolates recovered from uterine swabs of mares with clinical signs of endometritis and to determine the distribution of SeeL/SeeM and SzeL/SzeM superantigens in isolates of Streptococcus equi subsp. equi (S. equi) and S. equi subsp. zooepidemicus (S. zooepidemicus). The conventional bacteriological techniques showed the vast majority of these isolates (78) were S. zooepidemicus with just 5 Streptococ...
Ribeiro MF, da Silveira JA, Bastos CV.Tick-borne diseases in horses are caused by the intraerythrocytic protozoan parasites Theileria equi and Babesia caballi. Although T. equi is highly endemic in Latin America, the New World vector of this important parasite is controversial. The aim of this study was to test the ability of nymph Amblyomma cajennense ticks acquire infection by T. equi following feeding on infected horses. Three experiments were performed: tick acquisition of T. equi from an experimentally infected horse, tick acquisition of T. equi from naturally infected foals and tick acquisition of T. equi from a chronically ...
Kutasi O, Bakonyi T, Lecollinet S, Biksi I, Ferenczi E, Bahuon C, Sardi S, Zientara S, Szenci O.The spread of lineage 2 West Nile virus (WNV) from sub-Saharan regions to Europe and the unpredictable change in pathogenicity indicate a potential public and veterinary health threat and requires scientific awareness. Objective: To describe the results of clinical and virological investigations of the 1st outbreak of a genetic lineage 2 WNV encephalomyelitis in horses. Methods: Seventeen horses with neurologic signs. Methods: Information regarding signalment, clinical signs, and outcome was obtained for each animal. Serology was performed in 15 cases, clinicopathological examination in 7 case...
Harris SP, Hines MT, Mealey RH, Alperin DC, Hines SA.Rhodococcus equi is an important respiratory pathogen of young foals for which a vaccine has long been sought. Two major impediments to effective vaccination are the functionally immature type I immune responses of neonatal foals and early exposure to the bacterium via the environment. Despite these obstacles, it appears that under specific circumstances foals can develop a protective immune response. In this study we investigated the protective mechanisms behind oral inoculation of foals with virulent R. equi bacteria. Two foals receiving an oral inoculum demonstrated accelerated development ...
Retamal P, Ríos M, Cheuquepán F, Abalos P, Pizarro-Lucero J, Borie C, Gutierrez J.Corynebacterium pseudotuberculosis is a widespread facultative intracellular pathogen that causes caseous lymphadenitis disease in sheep and goats, and generates cutaneous abscesses and granulomas in horses and cattle. Although some genes have been studied for diagnostic and phylogenetic analysis within the genus Corynebacterium, at subspecies level the pathogen has been poorly analyzed. The aim of this study was to characterize C. pseudotuberculosis strains isolated from domestic animals, through the sequencing of a hypervariable rpoB gene segment. As result, there were identified host associ...
Breuhaus BA.Regulatory control of the thyroid gland in horses is similar to other species. Clinical signs of hypothyroidism in adult horses are minimal. Several drugs and physiologic and pathophysiological states can cause circulating thyroid hormone concentrations to be low without actual pathology of the thyroid gland. Thus, nonthyroidal factors must be ruled out before a diagnosis of hypothyroidism can be made. Thyroid hormone supplementation seems to be well tolerated, even in euthyroid horses. Neonatal foals have very high circulating thyroid hormone concentrations, and deficiencies result in signif...
Sturgill TL, Strong D, Rashid C, Betancourt A, Horohov DW.Production of the Th1 cytokine interferon gamma (IFNγ) is associated with resistance to intracellular pathogens, including Rhodococcus equi. While neonatal foals are initially deficient in IFNγ production, expression of this cytokine increases throughout their first year of life. This is presumably the result of stimulation by environmental antigens including pathogen associated molecular patterns (PAMPS) signaling through toll-like receptors (TLR). This increased expression of IFNγ is likewise associated with an age-related resistance to R. equi infection. While immunostimulants containing...
Maddox TW, Williams NJ, Clegg PD, O'Donnell AJ, Dawson S, Pinchbeck GL.The increasing prevalence of antimicrobial resistance in bacteria represents a considerable problem for human and veterinary medicine, causing complications in the treatment of infections. Resistance in Escherichia coli from horses has been documented in commensal and pathogenic strains, but little information exists regarding the prevalence of such bacteria in hospitalised horses or associated risk factors. A longitudinal cohort study was conducted of 103 horses admitted to a referral equine hospital for more than 48 h, with faecal samples collected on hospital admission and subsequently ever...
McClure S, Sibert G, Hallberg J, Bade D.The efficacy and safety of sustained release ceftiofur administered twice, 4 days apart, for treatment of horses with naturally acquired Streptococcus equi subsp. zooepidemicus (Strep. zoo.) pneumonia was evaluated in a multicenter, placebo-controlled, double-blinded, randomized clinical trial. The study included 373 horses (278 treated and 95 placebos) with naturally acquired pneumonia. Inclusion in the statistical analyses for treatment efficacy for Strep. zoo. required recovery of ≥10(4) CFU/mL of Strep. zoo. on the primary isolation plate which resulted in 201 cases (145 treated and 56 p...
Hébert L, Moumen B, Duquesne F, Breuil MF, Laugier C, Batto JM, Renault P, Petry S.Taylorella equigenitalis is the causative agent of contagious equine metritis (CEM), a sexually transmitted infection of horses. We herein report the genome sequence of T. equigenitalis strain MCE9, isolated in 2005 from the urethral fossa of a 4-year-old stallion in France.
Hijazin M, Ulbegi-Mohyla H, Alber J, Lämmler C, Hassan AA, Prenger-Berninghoff E, Weiss R, Zschöck M.An Arcanobacterium haemolyticum strain isolated from a postcastrational lesion of a horse was identified phenotypically and genotypically. The latter was performed by sequencing the 16S-23S rDNA intergenic spacer region (ISR), by amplification of the gene encoding A. haemolyticum phospholipase D, by amplification of A. haemolyticum specific parts of ISR-23S rDNA and by amplification of the newly described CAMP factor family protein encoding gene of A. haemolyticum. This indicates (as described previously for seven additional A. haemolyticum strains; Hassan et al. 2009) that A. haemolyticum see...
Ryan PL, Christiansen DL, Hopper RM, Walters FK, Moulton K, Curbelo J, Greene JM, Willard ST.Uterine and placental infections are the leading cause of abortion, stillbirth, and preterm delivery in the mare. Whereas uterine and placental infections in women have been studied extensively, a comprehensive examination of the pathogenic processes leading to this unsatisfactory pregnancy outcome in the mare has yet to be completed. Most information in the literature relating to late-term pregnancy loss in mares is based on retrospective studies of clinical cases submitted for necropsy. Here we report the development and application of a novel approach, whereby transgenically modified bacter...
Lengacher B, Kline TR, Harpster L, Williams ML, Lejeune JT.Manure from draft animals deposited in fields during vegetable and fruit production may serve as a potential source of preharvest pathogen contamination of foods. To better quantify this risk, we determined the prevalence of Escherichia coli O157:H7 in horses. Between June and September 2009, freshly voided fecal samples were collected from horses stabled on 242 separate premises in Ohio, USA. Overall, the prevalence of E. coli O157:H7 was 1 of 242 (0.4% prevalence, 95% confidence interval [CI] = 0.01 to 2.28). E. coli O157:H7 was recovered from none of the 107 equine fecal samples (0% prevale...
Szczerba-Turek A, Siemionek J, Bancerz-Kisiel A, Raś A, Szweda W.The aim of the study was to analyse a part of the sequence of the E5 gene of bovine papillomaviruses (BPV) associated with equine sarcoids in Polish horses. Samples of 40 skin lesions obtained from 29 horses were collected for molecular examination. The PCR amplicons of BPV DNA were detected in 38 specimens. After phylogenetic analysis 37 specimens were recognized as BPV-1 and one as BPV-2. Phylogenetic analysis has allowed the classification of the amplicons into two phylogenetic groups (A1,) and four separate isolates (2, 10, 16, 17).
Aalsburg AM, Erdman MM.Taylorella equigenitalis is the etiologic agent of contagious equine metritis (CEM), a venereal disease of horses. A total of 82 strains of T. equigenitalis isolated in the United States were analyzed by pulsed-field gel electrophoresis (PFGE) after digestion of genomic DNA with restriction enzyme ApaI. Twenty-eight of those strains isolated from horses in the 2009 U.S. outbreak (CEM09) were further analyzed with NotI and NaeI enzymes. When ApaI alone was used for analysis, the 82 isolates clustered into 15 different genotypes that clearly defined groups of horses with known epidemiological co...
Tolesano-Pascoli GV, Torga K, Franchin AG, Ogrzewalska M, Gerardi M, Olegário MM, Labruna MB, Szabó MP, Marçal Júnior O.This is a report of tick species, parasite prevalence and infestation intensity of birds in a forest fragment (18° 56' 57'' S and 48° 12' 14'' W) within the Brazilian cerrado (savanna), in the municipality of Uberlândia, State of Minas Gerais, Brazil. A total of 162 birds from 26 species were captured. One adult tick, 296 larvae and 67 nymphs were found on passerine birds. Of these, it was identified 31 larvae and 27 nymphs of Amblyomma longirostre, 17 nymphs of A. nodosum, one A. cajennense larvae and one male of Rhipicephalus sanguineus. All other ticks were identified as Amblyomma sp. la...
Botton SA, Pereira DI, Costa MM, Azevedo MI, Argenta JS, Jesus FP, Alves SH, Santurio JM.Pythium insidiosum is a fungus-like organism present in subtropical and tropical areas, such as Brazil, known to infect humans and various animal species. P. insidiosum is the etiological agent of pythiosis, an emerging and granulomatous disease characterized mainly by cutaneous and subcutaneous lesions in horses, the principal species affected. Accurate diagnosis of pythiosis and identification of its causal agent by microbiological and serological tests can be often difficult and inconclusive principally for horses and humans. The aim of this study was to evaluate the application of the prev...
Winther L, Baptiste KE, Friis C.Ampicillin concentrations in pulmonary epithelial lining fluid (PELF) and plasma was studied after single intravenous ampicillin administration (15mg/kg) or single intragastric administration of its prodrug, pivampicillin (19.9mg/kg) to horses and discussed in relation to minimum inhibitory concentrations (MIC) of common equine respiratory pathogens. After intravenous administration, elimination of ampicillin was fast and not detectable in plasma after 12h in three out of six horses. Pivampicillin was absorbed well in non-fasted horses with an oral bioavailability of 36%. The degree of penetra...
Haenni M, Targant H, Forest K, Sévin C, Tapprest J, Laugier C, Madec JY.Coagulase-positive staphylococci (CoPS) are potential causative agents of equine infections, but they are rarely responsible for the death of the animal. In the current study, staphylococci implicated in the death or euthanasia of horses were retrospectively studied in 3,457 necropsies performed over a decade (1995-2006). Morbidity associated with CoPS was 1.7%, representing 60 isolates of CoPS, which were identified as Staphylococcus aureus (59) and Staphylococcus pseudintermedius (1). Coagulase-positive staphylococci (alone or in association with another bacterial species) were associated wi...
Hall TL, Tell LA, Wetzlich SE, McCormick JD, Fowler LW, Pusterla N.Ceftiofur, a third generation cephalosporin, demonstrates in vitro efficacy against microorganisms isolated from septicemic neonatal foals. This pharmacokinetic study evaluated the intravenous and subcutaneous administration of ceftiofur sodium (5 mg/kg body weight; n = 6 per group) and subcutaneous administration of ceftiofur crystalline free acid (6.6 mg/kg body weight; n = 6) in healthy foals. Plasma ceftiofur- and desfuroylceftiofur-related metabolite concentrations were measured using high performance liquid chromatography following drug administration. Mean (±SD) noncompartmental pharma...
Yeargan MR, Howe DK.Equine protozoal myeloencephalitis (EPM) is a common neurologic disease of horses that is caused by the apicomplexan pathogen Sarcocystis neurona. To help improve serologic diagnosis of S. neurona infection, we have modified existing enzyme-linked immunosorbent assays (ELISAs) based on the immunogenic parasite surface antigens SnSAG2, SnSAG3, and SnSAG4 to make the assays polyvalent, thereby circumventing difficulties associated with parasite antigenic variants and diversity in equine immune responses. Two approaches were utilized to achieve polyvalence: (1) mixtures of the individual recombin...
Marsh GA, Todd S, Foord A, Hansson E, Davies K, Wright L, Morrissy C, Halpin K, Middleton D, Field HE, Daniels P, Wang LF.Bat-to-horse transmission of Hendra virus has occurred at least 14 times. Although clinical signs in horses have differed, genome sequencing has demonstrated little variation among the isolates. Our sequencing of 5 isolates from recent Hendra virus outbreaks in horses found no correlation between sequences and time or geographic location of outbreaks.
Bach BC, Leal DB, Ruchel JB, Souza Vdo C, Maboni G, Dal Pozzo M, Schlemmer KB, Alves SH, Santurio JM.NTPDase (EC 3.6.1.5) occurs in lymphocytes and plays an important role in immune function, in that hydrolyzes extracellular nucleoside tri- and/or diphosphates to form AMP. Pythium insidiosum causes the disease pythiosis, a pyogranulomatous disease of horses, dogs, cattle, cats and humans. Most antifungal drugs are ineffective against this pathogen, and immunotherapy, a treatment approach that relies on the injection of P. insidiosum antigen, has been successfully used in humans and horses to manage this disease. In this study, we investigated NTPDase activity in lymphocytes from rabbits inocu...
Munday JS, Hardcastle MR, Sim M.A 10-year-old horse presented with two 3-cm diameter exophytic masses over the fetlock. Histology was consistent with a hyperplastic squamous papilloma and numerous cell changes consistent with papillomavirus (PV) infection were visible. Partial sequences of PV L1 and E1 ORFs were amplified using consensus PCR primers. The sequences were most similar to Equus caballus type 1 (EcPV1). However, as the sequences were only around 73% similar to EcPV1, they appear to be from a novel PV type that is likely to be within the genus. The papillomas were treated with topical imiquimod and resolved withi...
Dabernat HJ, Delmas CF, Tainturier DJ, Lareng MB.The in vitro susceptibility of recent clinical isolates of Haemophilus equigenitalis to various antimicrobial agents was determined by the disk diffusion test and the World Health Organization-International Collaborative Study agar dilution procedure. Ampicillin and tetracycline were the most active drugs. All strains were susceptible to beta-lactam antibiotics, chloramphenicol, trimethoprim-sulfamethoxazole, nalidixic acid, nitrofurantoin (Furadantin), and bacitracin. All but two strains were resistant to streptomycin, whereas all strains were susceptible to the other aminocyclitol antibodies...
Meehan M, Burke FM, Macken S, Owen P.Streptococcus equi possesses a haem-uptake system homologous to that of Streptococcus pyogenes and Streptococcus zooepidemicus. The system consists of two ligand-binding proteins (Shr and Shp) and proteins (HtsA-C) with homology to an ABC transporter. The haem-uptake system of S. equi differs from that of S. pyogenes and S. zooepidemicus in that Shr is truncated by two-thirds. This study focused on the SeShr, SeShp and SeHtsA proteins of S. equi. Analysis of shr, shp and shphtsA knockout mutants showed that all three proteins were expressed in vitro and that expression was upregulated under co...
Johnson E, Atwill ER, Filkins ME, Kalush J.Cryptosporidium parvum and Giardia duodenalis are now recognized as primary enteric pathogens in animals and humans. Regulatory agencies, such as the Environmental Protection Agency are under increasing pressure to reduce the concentration of these protozoa in surface waters. Given the popularity of recreational riding of horses on public land in California backcountry, concerns have been raised by various regulatory agencies as to whether horses used for backcountry recreation are a significant source of C. parvum and G. duodenalis for the environment. The prevalence of fecal shedding of Cryp...
Zhao A, Zhang Y, Wang W, Jing B, Xing J, Tao D, Zhao W, Qi M.Enterocytozoon bieneusi, a zoonotic pathogen, has the potential to infect both immunocompromised and immunocompetent humans. It is found in large number of animals; however, not much is known regarding its prevalence in equine animals, particularly donkeys. This is the first molecular epidemiological evaluation of E. bieneusi in 178 free-ranging donkeys from five countrysides; and 502 farmed donkeys from 18 farms in 12 cities of Xinjiang, China by Nested PCR. Results: E. bieneusi was detected in 2.5% (17/680) donkeys, with 2.6% (13/502) in farmed and 2.2% (4/178) in free-ranging ones. Sequence...
Carretero M, Rodríguez C, San Andrés MI, Forés P, de Lucas JJ, Nieto J, Waxman S, San Andrés MD, González F.The pharmacokinetic behaviour of marbofloxacin, a new fluoroquinolone antimicrobial agent developed exclusively for veterinary use, was studied in mature horses (n = 5) after single-dose i.v. and i.m. administrations of 2 mg/kg bwt. Drug concentrations in plasma were determined by high performance liquid chromatography (HPLC) and data obtained were subjected to compartmental and noncompartmental kinetic analysis. This compound presents a relatively high volume of distribution (V(SS) = 1.17 +/- 0.18 l/kg), which suggests good tissue penetration, and a total body clearance (Cl) of 0.19 +/- 0.042...
Tolesano-Pascoli GV, Torga K, Franchin AG, Ogrzewalska M, Gerardi M, Olegário MM, Labruna MB, Szabó MP, Marçal Júnior O.This is a report of tick species, parasite prevalence and infestation intensity of birds in a forest fragment (18° 56' 57'' S and 48° 12' 14'' W) within the Brazilian cerrado (savanna), in the municipality of Uberlândia, State of Minas Gerais, Brazil. A total of 162 birds from 26 species were captured. One adult tick, 296 larvae and 67 nymphs were found on passerine birds. Of these, it was identified 31 larvae and 27 nymphs of Amblyomma longirostre, 17 nymphs of A. nodosum, one A. cajennense larvae and one male of Rhipicephalus sanguineus. All other ticks were identified as Amblyomma sp. la...
Higuchi T, Hashikura S, Gojo C, Inui T, Satoh S, Yoshida M, Ishiyama T, Yamada H, Takai S.An enzyme-linked immunosorbent assay (ELISA) for detection of serum IgG antibodies against Tween 20-extracted antigen of strain ATCC 6939 was applied in Hidaka, Japan to a total of 752 sick foals showing a variety of signs of infectious disease. An optical density (OD) value of more than 0.3 was tentatively fixed to be positive on the basis of readings made of healthy horse sera in previous studies. During a 2 year study, 138 of the 752 sick foals showed an OD value of 0.3 or higher and were designated as 'suspected of R. equi infection'. Age distribution during the initial medical examination...
Arafa AA, Hedia RH, Dorgham SM, Ibrahim ES, Bakry MA, Abdalhamed AM, Abuelnaga ASM.The World Health Organization considers multidrug-resistant (MDR) a major global threat. Horses harbor commensal isolates of this bacterial species and potentially serve as reservoirs for human MDR bacteria. This study investigated antimicrobial resistance in horses caused by extended-spectrum β-lactamase (ESBL)-producing . Unassigned: One hundred fifty-nine nasal swab samples were collected from horses with respiratory distress not treated with cefotaxime and erythromycin. Biochemical and serological identification was performed on all samples. Polymerase chain reaction (PCR) was used to de...
Nansen P, Grønvold J, Henriksen SA, Wolstrup J.Interactions between the predacious hyphomycete Arthrobotrys oligospora and third-stage larvae of nine animal-parasitic nematodes were tested in vitro. The trap-inducing capabilities of the ruminant trichostrongylus Cooperia oncophora, C. curticei, Haemonchus contortus and Ostertagia ostertagi and of equine cyathostomes were almost comparable to those of free-living soil nematodes, and significantly higher than those of the porcine Oesophagostomum dentatum and Oe. quadrispinulatum and of the murine Nematospiroides dubius. The trap-forming potential of Dictyocaulus viviparus was poor. All anima...
The Journal of parasitologyJanuary 23, 2003
Volume 88, Issue 6 1252-1254 doi: 10.1645/0022-3395(2002)088[1252:EOHTAD]2.0.CO;2
Dubey JP, Saville WJ, Sreekumar C, Shen SK, Lindsay OS, Pena HF, Vianna MC, Gennari SM, Reed SM.The effect of moist heat and several disinfectants on Sarcocystis neurona sporocysts was investigated. Sporocysts (4 million) were suspended in water and heated to 50, 55, 60, 65, and 70 C for various times and were then bioassayed in interferon gamma gene knockout (KO) mice. Sporocysts heated to 50 C for 60 min and 55 C for 5 min were infective to KO mice, whereas sporocysts heated to 55 C for 15 min and 60 C or more for 1 min were rendered noninfective to mice. Treatment with bleach (10, 20, and 100%), 2% chlorhexidine, 1% betadine, 5% o-benzyl-p-chlorophenol, 12.56% phenol, 6% benzyl ammoni...
Corona A, Cherchi R.Bacteriological surveillance is little applied in management of equine frozen semen but it is quite important to verify the microbial contamination in order to find out the chance of transmission of pathology to the mare in AI. Authors describe a qualitative and quantitative analysis for bacterial contamination on long time (3-17 years) equine frozen semen stored in liquid nitrogen. The semen checked, produced in Italy and in another Europe country, was cryopreserved in liquid nitrogen inside sealed plastic straws. One hundred and ten straws were checked out for pathogenic and no pathogenic ba...
Lallier R, Higgins R.In this study we describe biochemical, toxigenic and surface characteristics of 33 motile Aeromonas isolated from diseased mammals, 3 from moribund marine mammals, 24 from healthy fish and 4 from moribund fish. Aeromonas hydrophila, A. caviae and A. sobria were isolated from both mammals and fish but at a different incidence. Aeromonas hydrophila was the predominant species isolated from clinical specimens; it was isolated from pneumonia, wound infections, septicemia and abortion in horses, cattle and pigs. Aeromonas sobria was isolated from one mammal and 11 healthy fish. Aeromonas caviae was...
Scopel e Silva D, de Castro CC, da Silva e Silva F, Sant'anna V, Vargas GD, de Lima M, Fischer G, Brandelli A, da Motta Ade S, Hübner Sde O.P34 is an antimicrobial peptide produced by a Bacillus sp. strain isolated from the intestinal contents of a fish in the Brazilian Amazon basin with reported antibacterial activity. The aim of this work was to evaluate the peptide P34 for its in vitro antiviral properties against canine adenovirus type 2 (CAV-2), canine coronavirus (CCoV), canine distemper virus (CDV), canine parvovirus type 2 (CPV-2), equine arteritis virus (EAV), equine influenza virus (EIV), feline calicivirus (FCV) and feline herpesvirus type 1 (FHV-1). The results showed that the peptide P34 exhibited antiviral activity a...
Shin SJ, Lein DH, Aronson AL, Nusbaum SR.A total of 19 pathogenic bacterial species was isolated from uterine swabs of 498 out of 1539 mares over 4 years. The swabs were taken by 5 veterinary clinicians using 2 different techniques. Bacterial contamination during swabbing was minimized by scrupulous attention to cleansing of the external genitalia and the perineal area, and in the handling of the culture specimen. The most prevalent organisms isolated were beta-haemolytic streptococcus (39%), Escherichia coli (27%) and Klebsiella pneumoniae (7%). Interpretation of microbiological findings correlated well with clinical findings when n...
Rutkowski M, Krzemińska-Fiedorowicz L, Khachatryan G, Kabacińska J, Tischner M, Suder A, Kulik K, Lenart-Boroń A.Frequent occurrence of microbial resistance to biocides makes it necessary to find alternative antimicrobial substances for modern veterinary medicine. The aim of this study was to obtain biodegradable silver nanoparticle-containing (AgNPs) foils synthesized using non-toxic chemicals and evaluation of their activity against bacterial pathogens isolated from oral cavities of cats, dogs and horses. Silver nanoparticle foils were synthesized using sodium alginate, and glucose, maltose and xylose were used as reducing agents. The sizes of AgNPs differed depending on the reducing agent used (xylose...
Al-Izzi SA, Al-Bassam LS.Pseudomonas mallei was isolated from pus samples obtained from 34 mallein-positive horses. The isolates were subjected to in vitro sensitivity test using 16 different antimicrobial discs. All isolates (34) were sensitive to sulfamethizole, gentamycin, tetracycline, sulfathiazole, kanamycin, tobramycin, streptomycin and a combination of trimethoprim and sulfamethoxazole while none of them were sensitive to cephalothin, colistin, ampicillin, penicillin and nitrofurantoin. Rifapicin, chloramphenicol and carbenicillin were effective against 32, 26 and 18 isolates respectively. The minimum inhibito...
Lord J, Carter C, Smith J, Locke S, Phillips E, Odoi A.Surveillance of antimicrobial resistance (AMR) among veterinary pathogens is necessary to identify clinically relevant patterns of AMR and to inform antimicrobial use practices. Streptococcus equi subsp. zooepidemicus and Rhodococcus equi are bacterial pathogens of major clinical importance in horses and are frequently implicated in respiratory tract infections. The objectives of this study were to describe antimicrobial resistance patterns and identify predictors of AMR and multidrug resistance (MDR) (resistance to three or more antimicrobial classes) among equine S. zooepidemicus and R. equi...
Ryan MP, McAuliffe O, Ross RP, Hill C.Lacticin 3147 is a broad-spectrum, two-component, lanthionine-containing bacteriocin produced by Lactococcus lactis DPC3147 which has widespread food and biomedical applications as a natural antimicrobial. Other two-component lantibiotics described to date include cytolysin and staphylococcin C55. Interestingly, cytolysin, produced by Enterococcus faecalis, has an associated haemolytic activity. The objective of this study was to compare the biological activity of lacticin 3147 with cytolysin. The lacticin 3147-encoding determinants were heterologously expressed in Ent. faecalis FA2-2, a plasm...
Muscatello G, Browning GF.Selective agar media have been used for many years to facilitate the isolation of Rhodococcus equi from environmental and clinical samples. However, characterisation of R. equi still requires the use of immunochemical or polymerase chain reaction (PCR) analysis to differentiate between virulent and avirulent isolates. Here, we describe a novel method to detect and differentiate between R. equi isolates using colony blotting and DNA hybridization. Radiolabelled PCR product derived from the R. equi rrnA gene and specific hybridization conditions enabled differentiation of colonies of R. equi fro...
Hondalus MK, Sweeney CR, Mosser DM.A Rhodococcus equi radiobinding assay has been developed using organisms labeled with 3H-uracil. These labeled organisms resemble their unlabeled counterparts with respect to colony morphology, viability, and buoyant density. Bacteria routinely incorporate between 5 x 10(-3) and 5 x 10(-2) counts per minute per colony forming unit (cfu) which in this assay allows the detection of fewer than 0.2 cfu per macrophage. Once incorporated, greater than 90% of the label remains bacterial associated for at least 4 h postlabeling. The majority of the label is trichloroacetic acid precipitable, partition...
Retamal P, Ríos M, Cheuquepán F, Abalos P, Pizarro-Lucero J, Borie C, Gutierrez J.Corynebacterium pseudotuberculosis is a widespread facultative intracellular pathogen that causes caseous lymphadenitis disease in sheep and goats, and generates cutaneous abscesses and granulomas in horses and cattle. Although some genes have been studied for diagnostic and phylogenetic analysis within the genus Corynebacterium, at subspecies level the pathogen has been poorly analyzed. The aim of this study was to characterize C. pseudotuberculosis strains isolated from domestic animals, through the sequencing of a hypervariable rpoB gene segment. As result, there were identified host associ...
Phumoonna T, Barton MD, Vanniasinkam T, Heuzenroeder MW.Rhodococcus equi remains a significant bacterial pathogen, causing severe pyogranulomatous pneumonia in foals aged 1-3 months. There is no effective vaccine currently available for the prevention of R. equi pneumonia. DNA vaccines are known to offer specific advantages over conventional vaccines. The aim of this study was to demonstrate efficacy of our recombinant DNA vaccine candidates, namely pcDNA3-Re1, pcDNA3-Re3 and pcDNA3-Re5 by combining a heat shock protein GroEL2 to a virulence-associated protein A (VapA) from R. equi to protect C3H/He mice against the R. equi infection. VapA was show...
Bravo-Ramos JL, Sánchez-Montes S, Sánchez-Otero MG, Ballados-Gonzalez GG, Gamboa-Prieto J, Romero-Salas D, Olivares-Muñoz A.Equine piroplasmosis is a parasitic illness caused by various protozoa of the Babesia and Theileria genera, which parasitize within red blood cells. The transmission of these pathogens occurs through certain genus of ticks, including Amblyomma, Haemaphysalis, Hyalomma, and Rhipicephalus. In recent times, an increase in the identification of new Theileria species and genotypes has been observed. This is further complicated by the presence of mixed Theileria infections in both mammals and tick vectors, particularly in regions where wildlife and livestock share habitats and vectors. Therefore, th...
Lawton K, Runk D, Hankin S, Mendonsa E, Hull D, Barnum S, Pusterla N.The aim of this study was to use environmental sampling to determine the frequency of detection of selected equine respiratory viruses and bacteria in horses attending a multi-week equestrian show during the winter months. At four time points during showing, environmental sponge samples were collected from all stalls on the property and tested for the presence of equine herpesvirus-1 (EHV-1), EHV-2, EHV-4, equine influenza virus (EIV), equine rhinitis B virus (ERBV), Streptococcus equi ss. equi (S. equi), and S. equi ss. zooepidemicus (S. zooepidemicus) using real-time PCR (PCR). Environmental...
Šenica P, Žele Vengušt D, Vengušt G, Kuhar U.Rotaviruses A (RVA) are a major cause of acute viral gastroenteritis in humans worldwide and are responsible for about two million hospitalizations per year. They can also infect other mammals such as pigs, calves, goats, lambs, and horses, in which they are also considered a major cause of viral diarrhea. While RVA is well studied in humans and domestic animals, its occurrence in wild ruminants is not well known. The RVA genome is a double-stranded RNA consisting of 11 segments, and genotyping is based on the VP7 (G) and VP4 (P) segments. Currently, there are 42G genotypes and 58P genotypes. ...
Samir A, Abdel-Moein KA, Zaher HM.The upsurge of diarrheagenic E. coli pathotypes carrying extended-spectrum beta-lactamases (ESBLs)/plasmid-mediated AmpC β-lactamase (pAmpC) among animals constitutes an emerging threat for humans and animals. This study investigated the burden of ESBL-/pAmpC-producing diarrheagenic E. coli among diarrheic foals and its potential public health implications. Rectal swabs were collected from 80 diarrheic foals. These swabs were processed to isolate and identify ESBL/pAmpC-producing E. coli using a selective culture medium, biochemical tests, phenotypic identification, and molecular identificati...
Ahedor B, Otgonsuren D, Zhyldyz A, Guswanto A, Ngigi NMM, Valinotti MFR, Kothalawala H, Kalaichelvan N, Silva SSP, Kothalawala H, Acosta TJ....Theileria equi causes equine piroplasmosis, an economically significant disease that affects horses and other equids worldwide. Based on 18S ribosomal RNA (18S rRNA sequences), T. equi can be classified into five genotypes: A, B, C, D, and E. These genotypes have implications for disease management and control. However, no conventional polymerase chain reaction (PCR) assays are available to differentiate the genotypes of T. equi. To overcome this limitation, we developed and evaluated PCR assays specific for the detection of each T. equi genotype. Methods: A pair of forward and reverse primers...
Lebrasseur O, More KD, Orlando L.Equine viral outbreaks have disrupted the socio-economic life of past human societies up until the late 19th century and continue to be of major concern to the horse industry today. With a seroprevalence of 60-80 per cent, equine herpesvirus 4 (EHV-4) is the most common horse pathogen on the planet. Yet, its evolutionary history remains understudied. Here, we screen the sequenced data of 264 archaeological horse remains to detect the presence of EHV-4. We recover the first ancient EHV-4 genome with 4.2× average depth-of-coverage from a specimen excavated in the Southeastern Urals and dated ...
Holguin-Rocha AF, Calle-Tobon A, Vásquez GM, Astete H, Fisher ML, Tobon-Castano A, Velez-Tobon G, Maldonado-Ruiz LP, Silver K, Park Y....Ticks are obligatory hematophagous ectoparasites that transmit pathogens among various vertebrates, including humans. The microbial and viral communities of ticks, including pathogenic microorganisms, are known to be highly diverse. However, the factors driving this diversity are not well understood. The tropical horse tick, Dermacentor nitens, is distributed throughout the Americas and it is recognized as a natural vector of Babesia caballi and Theileria equi, the causal agents of equine piroplasmosis. In this study, we characterized the bacterial and viral communities associated with partial...
