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.
Peterson AE, Davis MF, Awantang G, Limbago B, Fosheim GE, Silbergeld EK.Animals on farms may be a potential reservoir and environmental source of methicillin-resistant Staphylococcus aureus (MRSA). Expanded surveillance methods for animal-associated MRSA are needed. To develop an environmental sampling method and to determine the correlation between animal and environmental MRSA positivity in the farm setting, we sampled horses, cattle, and their local environments at several farms in the mid-Atlantic United States. We obtained nasal swabs from 13 racehorses at first visit, and 11 racehorses at the same farm eight weeks later. We also sampled 26 pleasure horses an...
Karakulska J, Fijałkowski K, Nawrotek P, Pobucewicz A, Poszumski F, Czernomysy-Furowicz D.The aim of this study was an analysis of the staphylococcal flora of the nasal cavity of 42 healthy horses from 4 farms, along with species identification of CoNS isolates and determination of resistance to 18 antimicrobial agents, particularly phenotypic and genotypic methicillin resistance. From the 81 swabs, 87 staphylococci were isolated. All isolates possessed the gap gene but the coa gene was not detected in any of these isolates. Using PCR-RFLP of the gap gene, 82.8% of CoNS were identified: S. equorum (14.9%), S. warneri (14.9%), S. sciuri (12.6%), S. vitulinus (12.6%), S. xylosus (11....
Schoster A, Arroyo LG, Staempfli HR, Shewen PE, Weese JS.Clostridium difficile and Clostridium perfringens are commonly associated with colitis in equids, but healthy carriers exist. Scarce information is available on the prevalence of Clostridium spp. in gastrointestinal compartments other than faeces in healthy horses, and it is unknown whether faecal samples are representative of proximal compartments. The objectives were to investigate the prevalence of C. difficile and C. perfringens in different intestinal compartments of healthy adult horses and to determine whether faecal samples are representative of colonization in proximal sites and overa...
Veronesi F, Laus F, Passamonti F, Tesei B, Piergili Fioretti D, Genchi C.The aim of the study was to investigate Borrelia burgdorferi sensu lato (s.l.) infection in horses exposed to heavy tick infestations. Blood samples of 98 healthy horses from 5 stud farms were examined by SNAP(®) 4D× and PCR to detect antibodies against B. burgdorferi s.l. and Borrelia DNA, respectively. Ten samples (15.3%) were antibody positive and 5 samples (5.1%) were both antibody and PCR positive. Sequence analysis showed the highest homology with the B. lusitaniae genospecies. No differences were found between sexes and stud farms, while age was significantly related to seropositivity...
Vaughan JA, Tkach VV, Greiman SE.Digeneans are endoparasitic flatworms with complex life cycles and distinct life stages that parasitize different host species. Some digenean species harbour bacterial endosymbionts known as Neorickettsia (Order Rickettsiales, Family Anaplasmataceae). Neorickettsia occur in all life stages and are maintained by vertical transmission. Far from benign however, Neorickettsia may also be transmitted horizontally by digenean parasites to their vertebrate definitive hosts. Once inside, Neorickettsia can infect macrophages and other cell types. In some vertebrate species (e.g. dogs, horses and humans...
Donahue JM, Timoney PJ, Carleton CL, Marteniuk JV, Sells SF, Meade BJ.This study was undertaken to investigate the prevalence of Taylorella asinigenitalis in a subset of the donkey population of Michigan and in other equids on farms on which the organism was identified. Other aims were to further characterize the carrier state in terms of persistence and preferred sites of colonization of T. asinigenitalis in the male donkey as well as determine the genotype of any isolates of the organism. Initial testing of 43 donkeys and 1 mule turned up 4 (9.3%) donkeys culture positive for T. asinigenitalis. The 4 culture-positive donkeys resided on 2 farms accommodating a ...
Werners AH, Bryant CE.Pattern recognition receptors (PRRs) on host cells detect pathogens to activate innate immunity which, in turn, initiates inflammatory and adaptive immune responses. Successful activation of PRRs is, therefore, critical to controlling infections and driving pathogen-specific adaptive immunity, but overactivity of PRRs causes systemic inflammation, which is detrimental to the host. Here we review the PRR literature as it relates to horses and speculate on the role PRRs may play in sepsis and endotoxaemia.
Smiet E, Haritova A, Heil BA, Fink-Gremmels J, Wijnberg ID.To compare the pharmacokinetics of the fourth generation cephalosporin, cefquinome, in neonatal foals, 6-week-old foals and mature New Forest ponies in order to recommend appropriate dosage regimens for use of this drug. Methods: Cefquinome was administered i.v. at 1 mg/kg bwt twice a day (q. 12 h), 1 mg/kg bwt 3 times a day (q. 8 h) or 4.5 mg/kg bwt q. 12 h to each age group (n = 6). Plasma cefquinome concentrations were analysed using high-performance liquid chromatography combined with electrospray tandem mass spectrometry. Results: Both foal age groups had comparable pharmacokinetic data e...
Pisano MB, Seco MP, Ré VE, Farías AA, Contigiani MS, Tenorio A.Venezuelan Equine Encephalitis (VEE) complex belongs to alphavirus genus in the family Togaviridae. Several species of this complex are pathogenic to humans. VEE infections can produce severe or mild disease, and many cases remain undiagnosed. A specific and sensitive reverse transcriptase nested polymerase chain reaction (RT-Nested PCR) method was developed for the detection of all VEE subtypes, including Rio Negro Virus (RNV) (subtype VI), which circulates only in Argentina. Degenerated primers were designed and thermal cycling parameters were standardized. This technique is suitable for rap...
Frost MJ, Zhang J, Edmonds JH, Prow NA, Gu X, Davis R, Hornitzky C, Arzey KE, Finlaison D, Hick P, Read A, Hobson-Peters J, May FJ, Doggett SL....To determine the cause of an unprecedented outbreak of encephalitis among horses in New South Wales, Australia, in 2011, we performed genomic sequencing of viruses isolated from affected horses and mosquitoes. Results showed that most of the cases were caused by a variant West Nile virus (WNV) strain, WNV(NSW2011), that is most closely related to WNV Kunjin (WNV(KUN)), the indigenous WNV strain in Australia. Studies in mouse models for WNV pathogenesis showed that WNV(NSW2011) is substantially more neuroinvasive than the prototype WNV(KUN) strain. In WNV(NSW2011), this apparent increase in vir...
Boyle AG, Boston RC, O'Shea K, Young S, Rankin SC.Streptococcus equi is the etiologic agent of a highly infectious upper respiratory disease of horses known as strangles. Bacterial culture methods and polymerase chain reaction (PCR) of nasopharyngeal washes and guttural pouch lavages are used routinely to test clinical and carrier animals for the presence of S. equi but no definitive or gold standard test method has been shown to be optimal. We hypothesized that (i) a flocked swab submerged in ten-fold serial dilution suspensions of S. equi prepared in 0.9% NaCl would detect more colony forming units (CFU) than a rayon swab when used to inocu...
Onishi JC, Park JW, Prado J, Eades SC, Mirza MH, Fugaro MN, Häggblom MM, Reinemeyer CR.Carbohydrate overload models of equine acute laminitis are used to study the development of lameness. It is hypothesized that a diet-induced shift in cecal bacterial communities contributes to the development of the pro-inflammatory state that progresses to laminar failure. It is proposed that vasoactive amines, protease activators and endotoxin, all bacterial derived bioactive metabolites, play a role in disease development. Questions regarding the oral bioavailability of many of the bacterial derived bioactive metabolites remain. This study evaluates the possibility that a carbohydrate-induc...
Schoster A, Staempfli HR, Arroyo LG, Reid-Smith RJ, Janecko N, Shewen PE, Weese JS.Point prevalence studies have reported carriage rates of enteric pathogens in healthy horses, but longitudinal data are lacking. Commensal E. coli is an indicator organism to evaluate antimicrobial resistance of enteric bacteria, yet there are limited data for horses. The objectives of this study were to investigate and molecularly characterize isolates of Clostridium difficile, Clostridium perfringens and Salmonella, collected sequentially over a one year period, and to determine the antibiotic susceptibility profile for E. coli. Fecal samples were collected monthly from 25 adult horses for o...
Yamanaka T, Nemoto M, Bannai H, Tsujimura K, Kondo T, Matsumura T, Muranaka M, Ueno T, Kinoshita Y, Niwa H, Hidari KI, Suzuki T.Since equine influenza A virus (H3N8) was transmitted to dogs in the United States in 2004, the causative virus, which is called canine influenza A virus (CIV), has become widespread in dogs. To date, it has remained unclear whether or not CIV-infected dogs could transmit CIV to horses. To address this, we tested whether or not close contact between horses and dogs experimentally infected with CIV would result in its interspecies transmission. Methods: Three pairs of animals consisting of a dog inoculated with CIV (10(8.3) egg infectious dose 50/dog) and a healthy horse were kept together in i...
Hewson J, Johnson R, Arroyo LG, Diaz-Mendez A, Ruiz-López JA, Gu Y, del Castillo JR.Healthy neonatal foals were treated with cefotaxime by bolus (40 mg/kg i.v. q6h for 12 doses; n=10) or by infusion (loading dose of 40 mg/kg i.v. followed by continuous infusion of a total daily dose of 160 mg/kg per 24 h for 3 days; n=5). Population pharmacokinetics was determined, and concentrations in cavity fluids were measured at steady state (72 h). Highest measured serum drug concentration in the bolus group was 88.09 μg/mL and minimum drug concentration (C(min)) was 0.78 μg/mL at 6-h postadministration (immediately before each next dose), whereas infusion resulted in a steady-state c...
Macpherson ML, Giguère S, Hatzel JN, Pozor M, Benson S, Diaw M, Sanchez LC, Vickroy TW, Tell L, Wetzlich S, Sims J.The objective of this study was to determine the pharmacokinetics of CCFA in mares with placentitis and evaluate the disposition of the drug in fetal fluids, fetal membranes, colostrum, and serum of foals. A secondary objective was to obtain pilot data regarding the efficacy of CCFA for improving foal survival in mares with placentitis. Twelve pregnant pony mares were enrolled in the study, inoculated with Streptococcus zooepidemicus, intracervically and assigned to one of three groups: CEFT (n = 3; administered CCFA only; 6.6 mg/kg, i.m., q96h); COMBO (n = 6; administered combination therapy ...
Wong DM, Ghosh A, Fales-Williams AJ, Haynes JS, Kanthasamy AG.The cervical spinal cords of 2 horses with equine degenerative myeloencephalopathy (EDM) were evaluated for evidence of oxidative damage to the central nervous system (CNS) using immunohistochemical staining for 3-nitrotyrosine (3-NT) and 4-hydroxynonenol (4-HNE). Neurons of the CNS from horses with EDM had positive immunohistochemical staining, whereas control samples did not, thus supporting the theory that oxidative damage is a potential underlying factor in horses with EDM. In addition, serum vitamin E concentration was low in both EDM-affected horses, and vitamin E concentration was also ...
Erol E, Locke SJ, Donahoe JK, Mackin MA, Carter CN.The goal of this retrospective study was to have a comprehensive picture of the β-hemolytic streptococci of horses including tissue/organ distributions and susceptibility patterns against specific antimicrobials between January 1, 2000 and December 31, 2010. A total of 2,497 β-hemolytic streptococci were isolated from 2,391 cases, of which Streptococcus equi subsp. zooepidemicus was the most frequent isolate (72.0%). Other species isolated were Streptococcus dysgalactia subsp. equisimilis (21.3%), Streptococcus equi subsp. equi (5.8%), and unidentified β-hemolytic streptococci (0.9%). As ex...
D'Alessandro WB, Humber RA, Luz C.Two isolates of Beauveria bassiana and one of Purpureocillium lilacinum (=Paecilomyces lilacinus) were found infecting Amblyomma cajennense engorged females collected on horses (0.15% infection rate from a total of 1982 specimens) and another two isolates of P. lilacinum and one Metarhizium anisopliae detected in soils (2.1% from 144 samples) collected in typical pasture habitats of this tick in Central Brazil from October 2009 to March 2011. Fungi were isolated from soils with Rhipicephalus sanguineus as surrogate baits. No fungi were found in ticks or soils during the driest months (May to A...
Malik P, Bálint A, Dán A, Pálfi V.Equine herpesvirus-1 (EHV-1) can be classified into distinct groups by single nucleotide polymorphisms (SNPs) in their genomes. Only a few of these can be associated with a special attribute of the virus. Differences in the ORF30 region can determine the neuropathogenic potential, while by substitutions in the ORF68 region several strain groups can be made. In previous studies no connection was found between the neuropathogenic potential and the SNPs in ORF68, but the occurrence of members of distinct groups in different outbreaks can facilitate epidemiological investigations because the geogr...
Vendrig JC, Fink-Gremmels J.Gastrointestinal defence in the new-born is limited in comparison to adults, due to an immature epithelial barrier function and deficits in both innate and adaptive immune responses. Consequently, neonates (including foals) are at increased risk of disturbance to mucosal homeostasis during initial intestinal colonisation that may lead to excessive inflammation and bacterial translocation into the bloodstream, resulting in septicaemia. Bacterial recognition by Pattern Recognition Receptors (PRRs) and their downstream regulation of cytokine release have been shown to be pivotal for gastrointesti...
Giudice E, Giannetto C, Furco V, Alongi A, Torina A.This study was undertaken to determine the prevalence of Anaplasma phagocytophilum infection in Equidae and investigate the possibility of exposure to the organism in Sicily (Southern Italy). During the study blood samples were collected in horses and donkeys housed in five of the nine provinces of Sicilian Island. Of 133 horses and 100 donkeys tested, respectively 9.0% and 6.0% were seroactive (IFAT) with A. phagocytophilum antigen. In only 4.7% of the horses, specific A. phagocytophilum DNA was recorded; in donkey, Anaplasma DNA was not found. Our results indicate a low prevalence of A. phag...
Priest HL, Irby NL, Schlafer DH, Divers TJ, Wagner B, Glaser AL, Chang YF, Smith MC.Borrelia burgdorferi, the etiologic agent of Lyme disease is a tick born spirochetal infection. Clinical signs of Lyme borreliosis are uncommon in horses, but when present they are often vague and nonspecific. In horses, Lyme borreliosis has been implicated in musculoskeletal, neurological, reproductive, and ocular disorders, including uveitis, but definitive diagnosis can be challenging as the causative agent is rarely isolated and serologic tests can be unreliable and do not confirm active disease. Here, we report two cases of equine uveitis associated with B. burgdorferi based on the identi...
Onishi JC, Park JW, Häggblom MM, Fennell MJ, Fugaro MN.A common sequella of chronic laminitis in horses is repeated abscesses with variable lameness and drainage. It is unclear whether the exudate represents the debridement phase of a non-septic inflammatory process involving clearance of laminar tissue damaged during the acute episode of laminitis, or a response to a microbial infection developed by ascent of microbes from the environment to the tissue via the white line. The objective of this study was to evaluate the possibility that an undiagnosed microbial infection in laminar tissue is present in laminar tissue collected from chronically lam...
Holý O, Matousková I, Holý V, Koukalová D, Chmelar D.Cronobacter spp. belongs to the family Enterobacteriaceae. It is a motile (peritricha) Gram-negative non-spore forming bacterium. At present, Enterobacter sakazakii is reported as a Cronobacter spp. species with 16 biogroups. It is a ubiquitous organism whose isolation used to be associated with a contaminated powdered infant formula and feed for neonates and infants. Information about the Cronobacter spp. species incidence in the environment, its potential dissemination and its vectors, is very limited. The authors have documented incidence of Cronobacter spp. in the nostril mucous membrane o...
van Eeden C, Williams JH, Gerdes TG, van Wilpe E, Viljoen A, Swanepoel R, Venter M.To determine which agents cause neurologic disease in horses, we conducted reverse transcription PCR on isolates from of a horse with encephalitis and 111 other horses with acute disease. Shuni virus was found in 7 horses, 5 of which had neurologic signs. Testing for lesser known viruses should be considered for horses with unexplained illness.
Butler CM, Sloet van Oldruitenborgh-Oosterbaan MM, Stout TA, van der Kolk JH, Wollenberg Lv, Nielen M, Jongejan F, Werners AH, Houwers DJ.Equine piroplasmosis (EP) has not been considered indigenous in The Netherlands. However, following the detection of an apparently indigenous subclinical Babesia caballi infection in a horse on Schouwen-Duiveland (an island in the Zeeland Province), a survey was undertaken between May and September 2010 to assess the prevalence of the causative agents of EP in the South-West of The Netherlands. Blood samples from 300 randomly selected horses were tested for specific antibodies against Theileria equi and B. caballi using an indirect fluorescence antibody test (IFAT), and for parasite DNA using ...
Ueno M, Kuroda N, Yahagi K, Ohtaki T, Kawanaka M.Commercial western blot (WB) assay was used to detect serum antibodies specific to Echinococcus multilocularis in 23 horses in which infection was confirmed by postmortem inspection at a slaughterhouse. Livers contained from 1 to >20 nodular lesions; foci diameter ranged from 1 to 25 mm. Antibody tests of serum from all 23 animals were negative for antigen bands at 7, 16, 18, and 26-28 kDa, which show specificity in the serum of human patients. However, sera from two infected horses with the largest nodules (diameter, 25 mm) showed positive response to one of the 22-kDa and 30-kDa antigen band...
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...
Lundström TS, Dahlén GG, Wattle OS.Swedish equine dental practices have empirically found that the prevalence of infundibular caries as a primary disorder in the first permanent premolar teeth (P2) of the horse upper jaw has increased during the last 10 years. A previously unknown bacterial species, Streptococcus devriesei (CCUG 47155T), which is related to Streptococcus mutans, has recently been isolated from these carious lesions. To understand the aetiology of caries in horses, it is essential to elucidate the relationship between S. devriesei and P2 infundibular caries. Methods: The anterior infundibulum of maxillary P2, or...
Bernardino P, James K, Barnum S, Corbin R, Wademan C, Pusterla N.Equine rhinitis B virus (ERBV) has been given little attention by practitioners compared to other respiratory viruses, mainly because of the lack of diagnostic modalities and association with clinical disease. The objective of the study was to determine the frequency of detection of ERBV in nasal secretions from 6568 horses with acute onset of respiratory signs. ERBV-positive qPCR results from nasal secretions submitted to a molecular diagnostic laboratory from 2013 to 2019 were reviewed. A total of 333 ERBV qPCR-positive samples (5.1%) were detected with increasing yearly frequency since the ...
The Journal of hygieneDecember 1, 1976
Volume 77, Issue 3 401-408 doi: 10.1017/s0022172400055789
Platt H, Atherton JG, Orskov I.An account is given of K. pneumoniae capsule types occurring in horses, with particular reference to strains originating from the genital tract in the mare and the external genitalia of the stallion. A survey of the prevalence of K. pneumoniae and E. aerogenes strains in the preputial flora of healthy stallions is described. The majority of horses were found to be carriers of these organisms. The cultural characteristics of these preputial strains are described and compared with those of K. pneumoniae strains associated with epidemic metritis in mares. The epidemiological significance of certa...
Dunsmore JD, Jue Sue LP.A survey was conducted on the prevalence of the major gastrointestinal parasites in 140 horses necropsied in Perth, Western Australia, during 1979 to 1982. Adult Strongylus vulgaris were found in 22.5 per cent of horses and verminous arteritis in 62.9 per cent. The peak worm prevalence was in November to January (summer). S edentatus had a similar prevalence and seasonality but S equinus was not found in this survey. Draschia megastoma and Habronema muscae were found in 66.2 per cent and 35.3 per cent of horses respectively. Infection is probably acquired in summer when 8 per cent of the Musca...
Otranto D, Colwell DD, Milillo P, Di Marco V, Paradies P, Napoli C, Giannetto S.Two species of Rhinoestrus (i.e. Rhinoestrus purpureus (Brauer) and Rhinoestrus usbekistanicus Gan) cause nasal myiasis in horses, donkeys and zebras. In the past 15 years myiasis caused by R. purpureus has been reported in Egypt and by R. usbekistanicus in Senegal and Niger, both in horses and in donkeys. With the aim to investigate the presence of this myiasis in autochthonous horses and donkeys from southern Italy and to study the seasonal trend of larval infection, 212 native horses were necropsied in two slaughterhouses in the Apulia region (site A) from January to November 2003, and 120 ...
Makrai L, Fodor L, Csivincsik A, Varga J, Senoner Z, Szabó B.The cultural, morphological, biochemical, serological characteristics and antibiotic susceptibility of 25 Rhodococcus equi strains isolated from lungs and lung abscesses of pneumonic foals and 5 R. equi strains isolated from immuno-compromised human patients were examined. All R. equi strains showed common cultural, morphological and biochemical characteristics both with conventional tests and on the basis of their enzyme profile. The R. equi strains examined were resistant to penicillins with the exception of ampicillin, to sulphamethazine and several strains also to sulphamethoxazole-trimeth...
Snyder JR, Pascoe JR, Hirsh DC.Positive cultures were obtained from 60 equine orthopedic cases during a 12 year period (1974-1985). These cases consisted of 34 long or cuboidal bone fractures, 13 arthrotomy/arthroscopy procedures for removal or internal fixation of a fracture, 7 proximal splint bone fractures, and 6 facial or mandibular fractures. Excluding the 13 arthrotomies, only 10 (21%) of the 47 were open fractures. Multiple organisms were isolated from 36 cases (20 long or cuboidal bone fractures, 7 splint bone fractures, 5 mandibular fractures, and 4 intra-articular fractures). Of the 142 isolates, 35 (24%) were mem...
Bolton T, Kuskie K, Halbert N, Chaffin K, Healy M, Lawhon S, Jackson A, Cohen N.Rhodococcus equi is an important pathogen of foals aged 1-6 months. Evidence exists that foals are exposed to a wide diversity of R. equi strains in their environment. However, limited data are available regarding the extent to which genotypic variation exists among isolates infecting individual foals. Therefore, electrophoresis of repetitive sequence-based polymerase chain reaction (rep-PCR) amplicons in an automated microfluidics chip format was used to genotype 9 virulent R. equi isolates obtained from distinct anatomic locations in a single foal. Four of the isolates were obtained from dif...
Spencer JA, Ellison SE, Guarino AJ, Blagburn BL.Equine protozoal myeloencephalitis (EPM) is a neurologic syndrome seen in horses from the Americas and is mainly caused by Sarcocystis neurona. Cell-mediated immune responses to mitogens have been shown to be reduced in horses with EPM, although it is not known whether the parasite causes this immunosuppression or if the immunosuppression is required for disease manifestation. Recently, a 29-kDa surface antigen from S. neurona merozoites was identified as being highly immunodominant on Western blot. This antigen has been sequenced and cloned, and the expressed protein has been named SnSAG1. Is...
Howe DK, MacKay RJ, Reed SM.Equine protozoal myeloencephalitis (EPM) can be caused by either of 2 related protozoan parasites, Sarcocystis neurona and Neospora hughesi, although S. neurona is the most frequent etiologic pathogen. Horses are commonly infected, but clinical disease occurs infrequently; the factors influencing disease occurrence are not well understood. Risk factors for the development of EPM include the presence of opossums and prior stressful health-related events. Attempts to reproduce EPM experimentally have reliably induced antibody responses in challenged horses but have not consistently produced acut...
Thieulent CJ, Sutton G, Toquet MP, Fremaux S, Hue E, Fortier C, Pléau A, Deslis A, Abrioux S, Guitton E, Pronost S, Paillot R.Equid alphaherpesvirus-1 (EHV-1) is one of the main pathogens in horses, responsible for respiratory diseases, ocular diseases, abortions, neonatal foal death and neurological complications such as equine herpesvirus myeloencephalopathy (EHM). Current vaccines reduce the excretion and dissemination of the virus and, therefore, the extent of an epizooty. While their efficacy against EHV-1-induced abortion in pregnant mares and the decreased occurrence of an abortion storm in the field have been reported, their potential efficacy against the neurological form of disease remains undocumented. No ...
Research in microbiologyFebruary 11, 2003
Volume 154, Issue 1 29-35 doi: 10.1016/s0923-2508(02)00003-7
Silva TA, Rodrigues PH, Ribeiro RN, Noronha FS, Farias Lde M, Carvalho MA.The influence of growth medium, hemin and menadione, blood source and atmosphere of incubation on the expression of hemolytic activity of 25 strains of Prevotella intermedia and Prevotella nigrescens was evaluated. The best hemolytic activity was observed for samples of both species growing in brain heart infusion agar and incubated in Brewer-like anaerobic jars for 48 h. Hemolysis was less intense and occurred later in the presence of hemin and menadione in solid media. beta-Hemolysis was detected for medium supplemented with horse or human blood and alpha-hemolysis was observed when sheep bl...
Lavoie JP, Couture L, Higgins R, Laverty S.Bacterial isolations were reviewed from equine trachea, guttural pouch, uterus, wounds, abscesses, blood, synovial fluid, and abdominal fluid submitted to the Clinical Bacteriology Laboratory of the School of Veterinary Medicine at the University of Montreal for aerobic bacterial culture from 1986 to 1988. Of the 733 samples submitted, 324 (44%) were positive for bacterial growth, and 233 antimicrobial sensitivity tests were performed. Seventy-six percent of all positive samples yielded one bacterial species and two were isolated from 22% of positive samples. Streptococcus zooepidemicus, Esche...
Alhassan A, Iseki H, Kim C, Yokoyama N, Igarashi I.Rapid, efficient, and reproducible procedures for isolating DNA before PCR gene amplification are essential for the diagnosis of piroplasms. In this study, we evaluated the ease and reliability of detecting Theileria equi by PCR using pre-extracted DNA samples (by QIAamp DNA Mini Kit and phenol-chloroform methods) compared with blood spotted on FTA cards as PCR templates. Although minimal variations in limit of detection were observed among the methods compared, overall, the use of pre-extracted DNA samples and blood spotted on FTA cards had comparable detection limits. These results indicate ...
Mendonça FS, Navarro MA, Uzal FA.To determine if there were significant differences produced by 5 of the most prevalent causes of equine enterocolitis, we studied retrospectively the gross and microscopic pathology of 90 cases of enterocolitis submitted to the San Bernardino laboratory of the California Animal Health and Food Safety Laboratory. Included were cases caused by Clostridium perfringens type C (CP; n = 20), Clostridioides difficile (CD; n = 20), Paeniclostridium sordellii (PS; n = 15), Salmonella enterica subspecies enterica serovar Typhimurium (ST; n = 20), and NSAID intoxication (NS; n = 15). ...
Gomez DE, Leclere M, Arroyo LG, Li L, John E, Afonso T, Payette F, Darby S.This study describes the clinicopathological findings, diagnostic approach, treatment, and factors associated with non-survival of diarrheic horses admitted to 4 Canadian university teaching hospitals between 2015 and 2019. A total of 300 horses, ≥1-year-old, with acute diarrhea were included and represented 1.6% (300/18 481; range: 0.7 to 3%) of admissions during that period, 70% of the horses survived to discharge. Testing for enteropathogens was limited to a single fecal culture for Salmonella spp. in most cases. An enteropathogen was identified in 14% (42/300) of the horses, but in the h...
Almeida RF, Garcia MV, Cunha RC, Matias J, Labruna MB, Andreotti R.Ticks are vectors of various pathogens, including Rickettsia spp., which are responsible for causing an emerging disease of global significance. In the present study, an epidemiological survey was performed to identify Rickettsia spp. of the spotted fever group (SFG) in ticks and wild hosts in a native forest adjacent to livestock farming activity. The ticks and blood were evaluated by a hemolymph test and by PCR using the primers CS78 and CS323, which target a partial sequence of the enzyme citrate synthase (gltA) gene. Positive samples by PCR were further tested with the primers Rr190.70p an...
Sheoran AS, Timoney JF, Tinge SA, Sundaram P, Curtiss R.The aim of this study was to investigate the intranasal immunogenicity for the horse of a Deltacya Deltacrp-pabA mutant (MGN-707) of Salmonella enterica serotype Typhimurium (S. typhimurium). MGN-707 caused no sign of disease, was not detected in feces and a single administration induced strong Salmonella-specific serum and nasal mucosal antibody responses. All ponies had made strong salmonella specific serum IgGa, IgGb, IgA and IgM antibody responses by day 25 after the first immunization. IgM responses to salmonella lipopolysaccharide (LPS) were short lived whereas salmonella specific serum ...
Tang Y, Liu G, Zhao S, Li K, Zhang D, Liu S, Hu D.Major histocompatibility complex (MHC) genes are the most polymorphic in vertebrates and the high variability in many MHC genes is thought to play a crucial role in pathogen recognition. The MHC class II locus DQA polymorphism was analyzed in the endangered Przewalski's horse, , a species that has been extinct in the wild and all the current living individuals descend from 12 founders. We used the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) to detect the polymorphism within the MHC DQA in 31 Przewalski's horses from two reintroduced populations. Consequently, o...
Wu J, Cui Y, Yu F, Muhatai G, Tao D, Zhao A, Ning C, Qi M.Piroplasmosis is a disease that negatively affects equine health worldwide. Hence, 324 blood samples were collected from grazing horses in ten sites in Xinjiang and testing them for the presence of Theileria equi and Babesia caballi by PCR of the EMA-1 gene and BC48 gene, respectively. Of the 324 blood samples, 161 (49.7%) were positive for equine piroplasms. The prevalence of T. equi was 38.9% (126/324), while that of B. caballi was 30.2% (98/324). The T. equi and B. caballi co-infection rate was 19.4% (63/324). From the 126 EMA-1 gene sequences and 98 BC48 gene sequences we obtained, 21 and ...
Marshall K, Marsella R.Previous studies documented antibiotic resistance in horses but did not focus on skin specifically. We investigated antibiotic resistance and correlations between resistance patterns in skin infections. Records from 2009 to 2019 were searched for Staphylococcal infection and susceptibility results. Seventy-seven cases were included. Organisms identified were S. aureus (48/77), S. pseudintermedius (7/77), non-hemolytic Staphylococcus (8/77), beta-hemolytic Staphylococcus (6/77), and other species (8/77). Samples included pyoderma (36/77), wounds (10/77), abscesses (15/77), incision sites (5/77)...
Goodman-Davis R, Figurska M, Cywinska A.Diarrhea in foals is a problem of significant clinical and economic consequence, and there are good reasons to believe microbiota manipulation can play an important role in its management. However, given the dynamic development of the foal microbiota and its importance in health and disease, any prophylactic or therapeutic efforts to alter its composition should be evidence based. The few clinical trials of probiotic preparations conducted in foals to date show underwhelming evidence of efficacy and a demonstrated potential to aggravate rather than mitigate diarrhea. Furthermore, recent studie...
Atherton JG, Pitt TL.Pseudomonas aeruginosa isolates from equine clinical material were categorised according to their serotype and phage type. Epidemiological evidence showed that serotypes 02a, 03, 04, 06, 09 and 010 were the cause of genital and non-genital infections; somatic type 03 accounted for 50 per cent of isolates. The laboratory tests used were of no value in predicting whether or not a particular isolate was likely to be a venereal pathogen, but all the serotypes encountered had the potential to be pathogenic, given a favourable environment in which to multiply.
Tomczuk K, Kostro K, Grzybek M, Szczepaniak K, Studzińska M, Demkowska-Kutrzepa M, Roczeń-Karczmarz M.For this study, 724 gastrointestinal tracts of slaughter horses were investigated to determine the prevalence, intensity of Anoplocephala perfoliata and tapeworm development stages over the second, third and fourth quarter of 2012 and the first quarter of 2013. For each positive horse, faecal samples were collected from the rectum or small colon for coproscopic examinations. The samples were analysed using dedicated modified sedimentation-flotation methods. In total, 52 horses were infected with A. perfoliata in the course of the study, with an overall prevalence of 7.2 %. The prevalence chang...
Fenton CS, Buckley TC.Rhodococcus equi is a gram positive, intracellular pathogen of foals worldwide. The aim of this study was to determine whether there was an increasing resistance occurring in Rhodococcus equi towards the antibiotics rifampin and erythromycin over a seven year period. The investigation was carried out with the use of E test strips (epsilometers) for rifampin and erythromycin in order to determine the Minimum Inhibitory Concentrations (MIC) values of Rhodococcus equi to these antibiotics. Results: The main results of this study found that the mean MICs were higher for erythromycin than for rifam...
Falcão MVD, Laroucau K, Vorimore F, Deshayes T, Santana VLA, Silva KPC, do Nascimento SA, de Castro RS, Araújo FR, Mota RA.Glanders is an infectious zoonosis caused by Burkholderia (B.) mallei that mainly affects equids. The objective of this work was to provide additional knowledge on the diversity of the strains circulating in Brazil. Six Burkholderia mallei isolates obtained during necropsies of glanderous horses between 2014 and 2017 in two different states (Pernambuco and Alagoas) were analyzed by polymerase chain reaction-high-resolution melting (PCR-HRM). While four strains (9902 RSC, BM_campo 1, BM_campo 3 and UFAL2) clustered in the L3B2 branch, which already includes the Brazilian 16-2438_BM#8 strain, tw...
Jiménez BLM, Elghandour MMMY, Adegbeye MJ, Tirado González DN, Tirado Estrada G, Salem AZM, Pacheco EBF, Pliego AB.In the race against deadly diseases, multiple drugs have been developed as a treatment strategy in livestock. Each treatment is based on a specific mechanism to find a suitable drug. Antibiotics have become a fundamental part of the equine industry to treat bacterial diseases. These antibiotics have specific doses and side effects, and understanding each parameter allows veterinarians to avoid or limit the adverse effects of such drugs. Use of antibiotics causes microbial imbalance, decreased microbial diversity and richness in both cecal and fecal samples. Antibiotics reduced metabolites prod...
Malmgren L, Olsson Engvall E, Engvall A, Albihn A.This study was initiated in order to investigate the bacterial flora of the stallion genital tract by taking consecutive samples from normal stallions in regular use. The objective was to determine whether any growth of potential pathogens, particularly P. aeruginosa and K. pneumoniae, in fresh semen and urethra was associated with the presence of inflammatory cells in the semen and whether bacterial growth had any effect on sperm morphology and pregnancy results. Sixteen stallions, only used for A.I., housed at 3 different commercial stud farms, were used. A wide variety of microorganisms was...
Chirino-Trejo JM, Prescott JF.The antigens extracted from strains belonging to seven capsular serotypes of Rhodococcus equi, as well as from two wild strains isolated from pneumonic foals, were examined. Whole-cell antigens and soluble products present in broth culture supernatants were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, electroblotted onto nitrocellulose, and stained with serum from hyperimmunized rabbits or foals. Foal sera used included sera from pneumonic animals with known titer to equi factors; from animals bled monthly on a farm with enzootic pneumonia, and from animals bled mont...
