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.
Munirah M, Wahyuni S, Wahid I, Hamid F.In Indonesia, malaria incidence is at a high rate despite maximum preventive efforts. Therefore, this study aims to determine the possibility of a reservoir among domestic animals in malaria-endemic areas. Animal blood was collected using EDTA tubes, then smeared and stained with Giemsa for microscopic identification. About 10 μl of blood was dropped on to a filter paper to capture DNA. Nested PCR was used for parasite molecular detection, while species were identified using the sequenced DNA. A total of 208 and 62 animal blood samples were collected from Gaura village, West Sumba and Fak...
Padalino B, Pellegrini F, Felici M, Zappaterra M, Catella C, Cordisco M, Lorusso E, Cirone F, Pratelli A.Respiratory disorders (RDs) are a common transport-related welfare consequence in horses. This prospective study described the journeys of horses transported to two slaughterhouses in Italy, documented the prevalence of potentially RD-related pathogens, and identified possible predisposing factors. Data were recorded from arrival until 48 h after arrival and included the collection of Deep Nasopharyngeal Swabs (DNS), journey details and welfare assessment of horses (n = 155). PCR was used to quantify the presence of influenza A virus, reovirus, equine herpesvirus type 1 and 4, adenovirus, r...
Jung C, Gentil M, Müller E.The objective of the study was to investigate the age dependent occurrence of different infectious agents in foals with diarrhea. Methods: Fecal samples, which were submitted to a commercial laboratory for a PCR-profile "Foal Diarrhea Pathogens" from 01.01.2021 up to 31.12.2022 (n=144), were examined for Equine Coronavirus (ECoV), , (), toxin-encoding genes , , , and , toxin-encoding genes and , as well as Rotavirus A via PCR. Results: Pathogens could be detected in a high proportion (42.9%) of the samples. Rotavirus A was the most prevalent pathogen in the current study, followed by clos...
Chhabra D, Nagra J, Manuja A, Singha HS, Vaid RK, Goutam U, Kumar B. poses a significant threat to equine health globally. The bacteria causes strangles, a respiratory disease characterized by enlarged, abscessed lymph nodes, leading to airway obstruction. The bacterium, a Gram-positive, chain-forming, Lancefield group C β-hemolytic , is closely related to and distinction between these species is challenging. The present study focused on characterization of isolates from horses in northern India, aiming at elucidation of their sugar fermentation patterns. Nasal and nasopharyngeal swabs collected from different geographical regions of northern India, yieldin...
Hain-Saunders N, Knight DR, Bruce M, Riley TV.Recent increases in community-associated Clostridioides difficile infections have highlighted the importance of monitoring toxigenic C. difficile from animal and environmental sources. We provide the complete circularized genomes of two toxigenic C. difficile strains isolated from feral horse faeces. Genome N64 (sequence type 964) consists of a single chromosome of 4,078,791 bp, while genome H251 (sequence type 963) comprises one chromosome (4,304,722 bp) and three plasmids (150,942 bp, 11,534 bp, and 9,074 bp).
Mazzei M, Sorvillo B, Sgorbini M, Bindi F, Perelli A, Laus F.(1) Background: Respiratory problems may be associated with pathogens among which viruses may play an important role in causing or promoting clinical signs. However, traditional diagnostic methods for equine infectious diseases, such as PCR, are limited to known pathogens and often miss rare or novel viruses. Metagenomic next-generation sequencing is a transformative method that allows the sequencing of all genomes present in a sample. Recent studies have used next-generation sequences to identify viral sequences in horses with unexplained respiratory symptoms, revealing potential links betwee...
Mazzei M, Sorvillo B, Sgorbini M, Bindi F, Perelli A, Laus F.(1) Background: Respiratory problems may be associated with pathogens among which viruses may play an important role in causing or promoting clinical signs. However, traditional diagnostic methods for equine infectious diseases, such as PCR, are limited to known pathogens and often miss rare or novel viruses. Metagenomic next-generation sequencing is a transformative method that allows the sequencing of all genomes present in a sample. Recent studies have used next-generation sequences to identify viral sequences in horses with unexplained respiratory symptoms, revealing potential links betwee...
Migdał A, Migdał Ł, Oczkowicz M, Tombarkiewicz B, Okólski A.Colostrum contains substances such as hormones, enzymes, polyamides, nucleic acid derivatives, and amino acid derivatives and also includes immunomodulating substances, proline-rich polypeptides, immunoglobulins (Ig) as well as bacteriostatic compounds. The aim of the study was to evaluate the impact of colostral Ig on the level of expression of selected Toll-like receptor genes (TLR3, TLR4, and TLR7). The experiments were conducted on 25 Polish Pony foals. Blood samples were collected according to the following scheme: before first suckling, at the 1st, 3rd, 5th, 10th, 20th, and 30th, day of ...
Cheong SH, Franklin-Guild R, Goodman LB, Lago-Alvarez Y, Lee YL, de Aguiar LH, de Amorim MD, Altier C.Fungal and bacterial culture is currently the primary method for pathogen detection and identification. Next-generation sequencing is a powerful method for detecting and identifying the presence of microbial DNA in samples. We evaluated the correlation between fungal and bacterial culture with next-generation sequencing in equine uterine samples. Fungal cultures (n=63) were evaluated based on their culture results. In culture positive (n=16) samples, next-generation sequencing identified the same organism in 10 samples (62.5%), 5 samples did not identify fungal agents, and 1 sample identified ...
Scupham AJ, Tong C.In 2018, a new virus, named equine parvovirus-hepatitis (EqPV-H), was discovered in a biologic product that had been administered to horses that subsequently developed clinical signs of equine serum hepatitis (Theiler disease). Further correlation of the virus with the disease sparked federal requirements that all equine biologics be free of EqPV-H. The initial quantitative real-time PCR (qPCR) test for EqPV-H has proved to be sensitive to co-extracted PCR inhibitors in template nucleic acids, causing false-negative results. We investigated the use of digital PCR (dPCR) as a more robust test. ...
Ryu SH, Jang B, Kim BS, Park KT.This is the first report describing the isolation and genome sequence of Flavobacterium ceti (F. ceti IJFC025) from a draining submandibular lymph node abscess in a 6-year-old mixed-breed mare in Korea. Since F. ceti is not a usual infectious pathogen that causes equine health problems, this study presents the complete genome sequence of F. ceti isolated from a submandibular lymph node abscess sample in Jeju, South Korea, in 2022. The entire genome sequence of F. ceti IJFC025 consisted of a 3,144,426-bp chromosome with 35.6 % G + C content. Gene prediction revealed that this strain possesse...
Köhne M, Hüsch R, Tönissen A, Schmidt M, Müsken M, Böttcher D, Hirnet J, Plötz M, Kittler S, Sieme H. subspecies (subsp.) is an important facultative pathogen in horses and can cause severe infections in other species including humans. Facing the post-antibiotic era, novel antimicrobials are needed for fighting bacterial infections. Bacteriophages (phages) are the natural predators of bacteria and discussed as a promising antimicrobial treatment option. The objective of this study was to isolate and characterize subsp. specific phages for the first time and to evaluate their efficacy and . In total, 13 phages with lytic activity were isolated and host ranges were determined. Two phages wit...
Sasaki M, Fukumoto N, Fukumoto S.A two-year-old male Japanese draft horse (known as a "Ban'ei horse") excreted eight cestodes. Based on their morphological features, they were identified as Anoplocephala perfoliata. The partial mitochondrial cytochrome c oxidase subunit 1 (COI) sequences of the worms were nearly identical to A. perfoliata isolated from horses in Europe. The results of phylogenetic analyses of COI revealed that our samples and the European isolates formed the same clade, which was separate from Chinese and Australian isolates. Ban'ei horses were developed by crossbreeding draft horses imported from European co...
Haywood LMB, Sheahan BJ.Equine colitis is a devastating disease with a high mortality rate. Infectious pathogens associated with colitis in the adult horse include Clostridioides difficile, Clostridium perfringens, Salmonella spp., Neorickettsia risticii/findlaynesis, and equine coronavirus. Antimicrobial-associated colitis can be associated with the presence of infectious pathogens. Colitis can also be due to non-infectious causes, including non-steroidal anti-inflammatory drug administration, sand ingestion, and infiltrative bowel disease. Current treatments focus on symptomatic treatment (restoring fluid and elect...
Fahey MJ, Harman RM, Thomas MA, Pugliese BR, Peters-Kennedy J, Delco ML, Van de Walle GR.We aimed to study the antimicrobial and pro-healing potential of equine mesenchymal stromal cell secreted products (i.e. secretome), collected as conditioned media (mesenchymal stromal cell-conditioned media, MSC CM), in a novel in vivo model of methicillin-resistant Staphylococcus aureus (MRSA)-inoculated equine thorax wounds. Methods: Prospective in vivo study. Methods: Two Thoroughbred geldings. Methods: Six full-thickness cutaneous wounds were created bilaterally on the dorsal thorax of two horses (n = 12 wounds/horse). Wounds on the left thoraces were inoculated with MRSA on day 0. Al...
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...
de Albuquerque CV, da Silva Andrade M, de Freitas MS, Paulino PG, Santos HA, de Tarso Landgraf Botteon P.Equine Piroplasmosis (EP) and Equine Granulocytic Anaplasmosis (EGA) are diseases that affect horses, transmitted by ixodid ticks, causing a nonspecific febrile syndrome. Equine Piroplasmosis is endemic in Brazil, and most horses are in enzootic stability. Serological and molecular studies carried out on horses in Brazil have shown the presence of Anaplasma phagocytophilum, however, the clinical relevance of this infection has not yet been established. The present study aims to evaluate the importance of Babesia caballi, Theileria equi, and A. phagocytophilum as etiological agents in horses wi...
Martineau M, Ambroset C, Lefebvre S, Kokabi É, Léon A, Tardy F.Mycoplasma spp. are wall-less bacteria with small genomes (usually 0.5-1.5 Mb). Many Mycoplasma (M.) species are known to colonize the respiratory tract of both humans and livestock animals, where they act as primary pathogens or opportunists. M. equirhinis was described for the first time in 1975 in horses but has been poorly studied since, despite regular reports of around 14% prevalence in equine respiratory disorders. We recently showed that M. equirhinis is not a primary pathogen but could play a role in co-infections of the respiratory tract. This study was a set up to propose the fir...
Li E, Wu X, Tang L, Yang M, Hornok S, Zhang C, Zhang Y, Zhao G, Wang Y.Babesia and Theileria species (Apicomplexa: Piroplasmida) are tick-borne protozoan parasites that can cause mild to severe infection in humans, wildlife, livestock and companion animals. To date, reports on the molecular study of piroplasms from wild living small mammals and their ticks are still limited, especially in Asia. This study encompassed an extensive survey involving 907 liver samples and 145 ixodid ticks from 16 different species of small mammals (Rodentia, Lagomorpha, Eulipotyphla). These were collected in 13 cities and counties in northern China. DNA extracts from these samples we...
Eydi J, Tukmechi A.The most serious problem in public health is salmonellosis, a common disease in horse. The aim of this study was to investigate the shedding of serotypes in healthy Caspian pony. We examined 143 pony's fecal samples collected from the north of Iran belonging to different ages and sexes. Samples were cultured, then identification of isolates were performed by common bacteriological methods and polymerase chain reaction (PCR). The PCR was also used to explore the presence of and genes as virulence factors in the isolates and all were assigned to antibiotic susceptibility test via disc diffusi...
Ochi A, Toya Y, Sengoku M, Tsuchiya S, Kishi D, Ueno T.Equine piroplasmosis (EP) is a protozoal disease affecting equids, caused by and . EP is conventionally diagnosed using microscopic, molecular, and/or serological methods, which are time-consuming. Consequently, there is a need for faster testing methods. In this study, we evaluated the application of the Sysmex XN-31 automated hematology analyzer, originally a rapid test for detecting malaria in humans, for the diagnosis of EP. The cultured parasites were measured using the XN-31 that had been customized for horse blood samples (XN-31m). The following parameters were evaluated: limit of dete...
Mizuguchi Y, Tsuzuki N, Ebana MD, Suzuki Y, Kakuda T. is an intracellular bacterium that causes suppurative pneumonia in foals. T-helper (Th) 1 cells play an important role in the protective response against . In mice and humans, the directionality of IgG switching reflects the polarization of Th-cell responses, but this has not been fully elucidated in horses. In this 4-year study, we classified -infected foals into surviving and non-surviving group and investigated differences in IgG subclass response to virulence-associated protein A, the main virulence factor of , between the groups. IgGa, IgGb, and IgG(T) titers were significantly higher in...
Tyrnenopoulou P, Tsilipounidaki K, Florou Z, Gkountinoudis CG, Tyropoli K, Starras A, Peleki C, Marneris D, Arseniou N, Lianou DT, Katsarou EI....The objectives of this study were (a) to detect zoonotic gastrointestinal pathogens in faecal samples of horses using the FilmArray GI Panel and (b) to identify variables potentially associated with their presence. Faecal samples collected from 224 horses obtained during a countrywide study in Greece were tested by means of the BioFire FilmArray Gastrointestinal (GI) Panel, which uses multiplex-PCR technology for the detection of 22 pathogens. Gastrointestinal pathogens were detected in the faecal samples obtained from 97 horses (43.3%). Zoonotic pathogens were detected more frequently in samp...
Lawrence KE, Gedye K, Carvalho L, Wang B, Fermin LM, Pomroy WE.To determine whether evidence for infection with (Ikeda) could be identified in samples of commercial red deer , horses, and working farm dogs in New Zealand. Unassigned: Blood samples were collected during October and November 2019 from a convenience sample of red deer (n = 57) at slaughter. Equine blood samples (n = 50) were convenience-sampled from those submitted to a veterinary pathology laboratory for routine testing in January 2020. Blood samples, collected for a previous study from a convenience sample of Huntaway dogs (n = 115) from rural regions throughout the North and ...
Ramsay L, Eberhardt C, Schoster A.Reports of leptospirosis in horses are limited. Objective: To describe the clinical and diagnostic findings of acute systemic leptospirosis in horses. Methods: Eleven client-owned horses presented to an equine hospital because of acute onset of disease between 2015 and 2023. Methods: Retrospective case series. Horses diagnosed with leptospirosis by 1 or more of urine PCR, serologic microscopic agglutination test (MAT), and histopathology. Results: Common clinical signs included lethargy (10), anorexia (10), fever (9), tachypnea (9), abnormal lung sounds (9), and epistaxis (6). Acute kidney inj...
Anandu S, Tanuj GN, Vijayasarathi MK, Manjusha KM, Samanta S, Bandyopadhyay S, Sankar M.Ocular setariasis is an ectopic infection caused by a parasite under the genus Setaria. Adult worms belong to the Setariidae family and typically reside in the peritoneal cavity of ungulates. However, immature forms of these species may aberrantly migrate to the eyes of cattle, buffalo, goats, horses and several other hosts, leading to corneal opacity and blindness. Here, we have distinguished the Setaria digitata collected from both equine and buffalo hosts based on the morphology, molecular profiling of mitochondrial cytochrome c oxidase subunit 1 (Cox1), cytochrome c oxidase subunit 3 (Cox3...
Campos AS, Franco AC, Godinho FM, Huff R, Candido DS, da Cruz Cardoso J, Hua X, Claro IM, Morais P, Franceschina C, de Lima Bermann T, Dos Santos FM....Western equine encephalitis virus (WEEV) is a mosquitoborne virus that reemerged in December 2023 in Argentina and Uruguay, causing a major outbreak. We investigated the outbreak using epidemiologic, entomological, and genomic analyses, focusing on WEEV circulation near the Argentina‒Uruguay border in Rio Grande do Sul state, Brazil. During November 2023‒April 2024, the outbreak in Argentina and Uruguay resulted in 217 human cases, 12 of which were fatal, and 2,548 equine cases. We determined cases on the basis of laboratory and clinical epidemiologic criteria. We characterized 3 fatal equ...
Veiga RF, Clarindo LN, Fensterseifer AL, Pompelli LH, Sfaciotte RAP, Schwarz DGG, Eloy LR, Ferraz SM.The objective of this study was to determine the prevalence of Streptococcus equi (S. equi subsp equi and S. equi subsp zooepidemicus) in the state of Santa Catarina and evaluate the antimicrobial susceptibility of the isolates. For this, 420 nasal swab samples were collected from randomly selected horses. Isolation and phenotypic characterization of the bacteria were performed by sowing on 5% sheep blood agar, followed by analysis of morphotinctorial characteristics and biochemical analysis. To differentiate the main beta-hemolytic Streptococcus in horses, the fermentation profiles of the sug...
Hartel PG, Summer JD, Hill JL, Collins JV, Entry JA, Segars WI.Several genotypic methods have been developed for determining the host origin of fecal bacteria in contaminated waters. Some of these methods rely on a host origin database to identify environmental isolates. It is not well understood to what degree these host origin isolates are geographically variable (i.e., cosmopolitan or endemic). This is important because a geographically limited host origin database may or may not be universally applicable. The objective of our study was to use one genotypic method, ribotyping, to determine the geographic variability of the fecal bacterium, Escherichia ...
Carnwath R, Graham EM, Reynolds K, Pollock PJ.Delayed healing associated with distal limb wounds is a particular problem in equine clinical practice. Recent studies in human beings and other species have demonstrated the beneficial wound healing properties of honey, and medical grade honey dressings are available commercially in equine practice. Equine clinicians are reported to source other non-medical grade honeys for the same purpose. This study aimed to assess the antimicrobial activity of a number of honey types against common equine wound bacterial pathogens. Twenty-nine honey products were sourced, including gamma-irradiated and no...
Ben Sallem R, Ben Slama K, Sáenz Y, Rojo-Bezares B, Estepa V, Jouini A, Gharsa H, Klibi N, Boudabous A, Torres C.The prevalence of extended-spectrum beta-lactamase (ESBL)- and plasmidic AmpC-beta-lactamase (pAmpC-BL)-producing Escherichia coli isolates has been studied in food-producing animals at the farm level in Tunisia, and recovered isolates were characterized for the presence of other resistance genes and integrons. Eighty fecal samples of food-producing animals (23 sheep, 22 chickens, 22 cattle, six horses, five rabbits, and two dromedaries) were obtained from 35 different farms in Tunisia in 2011. Samples were inoculated onto MacConkey agar plates supplemented with cefotaxime (2 mg/L) for cefot...
Beards GM, Brown DW, Green J, Flewett TH.Pleomorphic virus-like particles have been observed by electron microscopy in the faeces of children and adults with diarrhoea. Some of these particles were approximately 100 nm in diameter and had a "fringe" of closely applied peplomers approximately 10 nm long; they closely resembled Berne virus of horses and Breda virus of calves, the two representatives of a newly proposed family called the Toroviridae. In one sample a toroidal nucleoprotein-like structure was observed within the particles. For two samples a buoyant density of 1.14 g/ml was determined by centrifugation through a sucrose de...
Chang YF, Ku YW, Chang CF, Chang CD, McDonough SP, Divers T, Pough M, Torres A.The objective of this study is to determine whether doxycycline, ceftiofur or tetracycline could be effectively used to treat equine Lyme disease. Ponies experimentally infected with Borrelia burgdorferi by tick exposure were treated with doxycycline, ceftiofur or tetracycline for 4 weeks (28 days). Doxycyline and ceftiofur treatment were inconsistent in eliminating persistent infection in this experimental model. However, tetracycline treatment seems to eliminate persistent infection. Although serum antibody levels to B. burgdorferi in all ponies declined gradually after antibiotic treatment,...
LeBlanc MM, Magsig J, Stromberg AJ.Low-volume uterine flush (n=401) was performed in 308 infertile mares to diagnose endometritis. Mares evaluated were either barren after three or more breedings or had two or more unsuccessful embryo recovery attempts during consecutive cycles. Culture results were compared with cytological and histological findings, efflux clarity and pH to substantiate that the micro-organisms recovered were truly pathogens. Cytological specimens were evaluated for presence of epithelial and inflammatory cells, bacteria, yeast and debris. Endometrial biopsies (n=110) were examined for the presence of neutrop...
Weaver SC, Bellew LA, Gousset L, Repik PM, Scott TW, Holland JJ.We evaluated genetic and phenotypic diversity within natural populations of the alphavirus, Eastern equine encephalomyelitis (EEE) virus. RNA fingerprinting revealed that most populations within infected hosts (unpassaged isolates) contained a consensus genotype along with minority genotypes differing in one to three T1-resistant oligonucleotides. Mutation frequencies appeared to be similar to those reported for other RNA viruses, suggesting that the slow rate of EEE virus evolution is not limited by fidelity of genome replication. Within a given year, genetic diversity was generally greater a...
Jacks SS, Giguère S, Nguyen A.The objective of this study was to determine in vitro activities of azithromycin (AZM), clarithromycin (CLR), and 20 other antimicrobial agents against Rhodococcus equi and other common equine bacterial pathogens. A total of 201 bacterial isolates from various equine clinical samples were examined. CLR was more active than AZM against R. equi, with MICs at which 90% of the isolates were inhibited of 0.12 and 1.0 micro g/ml, respectively. Other antimicrobial agents highly active against at least 90% of R. equi isolates in vitro included rifampin, gentamicin, and imipenem. Both AZM and CLR showe...
De Martino L, Lucido M, Mallardo K, Facello B, Mallardo M, Iovane G, Pagnini U, Tufano MA, Catalanotti P.Methicillin-resistant staphylococci (MRS) were isolated from nasal swabs of 56 of 159 (35.2%; 95% confidence interval [CI]: 27.9-43.2%) healthy horses. Two nasal swabs were collected from each horse; 43 of 159 (27%; 95% CI: 20.5-34.8%) of the cohort were colonized by MRS strains in 1 nostril, while in the remaining 13 of 159 (8.2%; 95% CI: 4.6-13.9%), different or identical MRS strains were isolated in both nostrils. Of the 29 humans in close contact with the horses tested, 4 (13.8%; 95% CI: 4.5-32.6%) were found to be carriers of MRS. All isolates were coagulase negative with the exception of...
Songer JG, Beckenbach K, Marshall MM, Olson GB, Kelley L.Isolates (n = 94) of Corynebacterium pseudotuberculosis were obtained from sheep, goats, horses, and cattle from various parts of the world. The isolates were characterized biochemically and by restriction endonuclease analysis of DNA. We found near homogeneity in the ability of isolates to ferment carbohydrates and to produce urease. All isolates produced phospholipase D and catalase. The ability of isolates from horses to reduce nitrate, the inability of isolates from sheep and goats to do so, and the correlation of this characteristic with results of restriction endonuclease analyses confir...
Woolcock JB, Farmer AM, Mutimer MD.The development of a selective medium for the isolation of Corynebacterium equi is described. The medium has been used to examine fecal samples from 127 horses of which 90 have been found to carry the organism.
Flaminio MJ, Rush BR, Davis EG, Hennessy K, Shuman W, Wilkerson MJ.Studies in infants and foals indicate an age-dependent maturation of peripheral lymphocyte subsets. The age-dependent relationship for maturation of cellular immune responses, such as phagocytosis and lymphocyte responses of the peripheral and pulmonary-derived leukocytes, has not been characterized in foals. Lymphocyte subpopulations, mitogen stimulation response of lymphocytes, lymphokine-activated killing cell activity, phagocytosis and oxidative burst activity, and serum immunoglobulin (Ig) classes G and M concentrations were determined in developing foals. This study illustrates age-depen...
Vo AT, van Duijkeren E, Fluit AC, Gaastra W.The aim of the present study was to contribute to the knowledge on extended-spectrum beta-lactamases (ESBL's), AmpC beta-lactamases and integrons in Enterobacteriaceae isolated from horses, which is still limited. The susceptibility of 1581 clinical isolates from animals to ceftiofur was tested. Most of these isolates (n=1347) originated from horses. Seven ceftiofur-resistant equine isolates (four Escherichia coli and three Klebsiella pneumoniae) were identified and all seven were multidrug-resistant. These isolates were further studied for the presence of ESBL's, AmpC beta-lactamases and clas...
Uiterwijk M, Ibáñez-Justicia A, van de Vossenberg B, Jacobs F, Overgaauw P, Nijsse R, Dabekaussen C, Stroo A, Sprong H.Ticks of the genus Hyalomma, which are vectors for several tick-borne diseases, are occasionally found in areas outside their endemic range including northern parts of Europe. The objective of this study was to analyse adult Hyalomma ticks that were recently found in the Netherlands. Methods: Hyalomma ticks were morphologically identified. Cluster analysis, based upon sequence data (cox1 barcoding) for molecular identification, and pathogen detection were performed. Additionally, a cross-sectional survey of horses was conducted to actively search for Hyalomma ticks in summer 2019. Analysis of...
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...
McDaniel TK, Dewalt KC, Salama NR, Falkow S.Because of limited genetic tools for use in Helicobacter pylori, tests routinely applied in other bacteria for demonstrating a gene's role in viability and other phenotypes have not been applied to this organism. In a mutational study of putative response regulator genes, we aimed to develop such tools for H. pylori. Methods: We attempted to mutate five response regulator genes by allelic exchange insertional mutagenesis. For genes that yielded no viable mutants, a second copy of the gene was inserted into the chromosome via a suicide vector, and it was seen if providing the second copy would ...
Becker K, Keller B, von Eiff C, Brück M, Lubritz G, Etienne J, Peters G.Staphylococcal food poisoning (SFP) caused by enterotoxigenic staphylococci is one of the main food-borne diseases. In contrast to Staphylococcus aureus, a systematic screening for the enterotoxins has not yet been performed on the genomic level for the coagulase-positive species S. intermedius. Therefore, the enterotoxigenic potential of 281 different veterinary (canine, n = 247; equine, n = 23; feline, n = 9; other, n = 2) and 11 human isolates of S. intermedius was tested by using a multiplex PCR DNA-enzyme immunoassay system targeting the staphylococcal enterotoxin genes sea, seb, sec, sed...
Balaratnasingam C, Kang MH, Yu P, Chan G, Morgan WH, Cringle SJ, Yu DY.Retinal ganglion cell (RGC) axonal structure and function in the optic nerve head (ONH) is predominantly supported by astrocytes and capillaries. There is good experimental evidence to demonstrate that RGC axons are perturbed in a non-uniform manner following ONH injury and it is likely that the pattern of RGC axonal modification bears some correlation with the quantitative properties of astrocytes and capillaries within laminar compartments. Although there have been some excellent topographic studies concerning glial and microvascular networks in the ONH our knowledge regarding the quantitati...
McCoy HE, Broder CC, Lottenberg R.The species specificities of plasminogen activation and binding of plasmin by pathogenic group C streptococci isolated from humans, horses, and pigs were examined. Of 56 streptococcal isolates, 52 elaborated plasminogen activator activity and 49 of these had specificity for plasminogen of the homologous host. Analysis of supernatants from 13 isolates indicated that the plasminogen activator activity resulted from secreted streptokinases. These 13 streptokinases were antigenically related and bound all three plasminogens, indicating that the binding recognition sites were conserved despite the ...
Magallanes S, Llorente F, Ruiz-López MJ, Martínez-de la Puente J, Soriguer R, Calderon J, Jímenez-Clavero MÁ, Aguilera-Sepúlveda P, Figuerola J.West Nile virus (WNV) is a re-emerging zoonotic pathogen with increasing incidence in Europe, producing a recent outbreak in 2020 in Spain with 77 human cases and eight fatalities. However, the factors explaining the observed changes in the incidence of WNV in Europe are not completely understood. Longitudinal monitoring of WNV in wild animals across Europe is a useful approach to understand the eco-epidemiology of WNV in the wild and the risk of spillover into humans. However, such studies are very scarce up to now. Here, we analysed the occurrence of WNV and Usutu virus (USUV) antibodies in ...
Magnarelli LA.Blood-engorged Coquillettidia perturbans, Psorophora ferox, Culex, Culiseta, and Aedes mosquitoes were collected principally by sweep net from salt marsh and woodland habitats in Connecticut. Of the 570 mosquitoes tested, precipitin tests identified the origins of 517 blood meals and revealed distinct host feeding patterns. Aedes mosquitoes fed chiefly on mammals; A. abserratus, A. cantator, and A. vexans showed selectivity for cattle and (or) horses. A. cantator also obtained blood from avian hosts and, in some instances, showed mixed passerine-mammal blood meals. These findings increase the ...
Lopez AM, Hines MT, Palmer GH, Alperin DC, Hines SA.Rhodococcus equi infects and causes pneumonia in foals between 2 and 4 months of age but does not induce disease in immunocompetent adults, which are immune and remain clinically normal upon challenge. Understanding the protective response against R. equi in adult horses is important in the development of vaccine strategies, since those mechanisms likely reflect the protective phenotype that an effective vaccine would generate in the foal. Twelve adult horses were challenged with virulent R. equi and shown to be protected against clinical disease. Stimulation of cells obtained from bronchoalve...
Reinemeyer CR, Nielsen MK.Equids are hosts to dozens of species of internal parasites that infect no other domestic animals. Virtually all horses, especially those exposed to pasture, experience some level of parasitism continuously. Despite pathologic evidence of parasitic damage in various organs and tissues, few parasitisms are manifested systemically in well-managed horses. Contrary to conventional wisdom, only three common parasitisms of horses are likely to be manifested as colic: Strongylus vulgaris, Parascaris equorum, and Anoplocephala perfoliata. This article discusses the life cycles, pathophysiology, manife...
Popoff MR.Tetanus is a neurologic disease of humans and animals characterized by spastic paralysis. Tetanus is caused by tetanus toxin (TeNT) produced by Clostridium tetani, an environmental soilborne, gram-positive, sporulating bacterium. The disease most often results from wound contamination by soil containing C. tetani spores. Horses, sheep, and humans are highly sensitive to TeNT, whereas cattle, dogs, and cats are more resistant. The diagnosis of tetanus is mainly based on the characteristic clinical signs. Identification of C. tetani at the wound site is often difficult.
Li F, Wang R, Guo Y, Li N, Feng Y, Xiao L.Limited data are available on infection rates and genetic identity of Enterocytozoon bieneusi and Giardia duodenalis in horses and donkeys. In this study, 865 fecal specimens were collected from donkeys (n = 540) and horses (n = 325) in three provinces and autonomous regions in northern China during 2015-2019. Enterocytozoon bieneusi was detected and genotyped by PCR and sequence analyses of the ribosomal internal transcribed spacer (ITS) and G. duodenalis was detected and genotyped by PCR and sequence analyses of the β-giardin, glutamate dehydrogenase, and triosephosphate isomerase g...
Mitchell C, Steward KF, Charbonneau ARL, Walsh S, Wilson H, Timoney JF, Wernery U, Joseph M, Craig D, van Maanen K, Hoogkamer-van Gennep A, Leon A....The equine disease strangles, which is characterized by the formation of abscesses in the lymph nodes of the head and neck, is one of the most frequently diagnosed infectious diseases of horses around the world. The causal agent, subspecies , establishes a persistent infection in approximately 10 % of animals that recover from the acute disease. Such 'carrier' animals appear healthy and are rarely identified during routine veterinary examinations pre-purchase or transit, but can transmit to naïve animals initiating new episodes of disease. Here, we report the analysis and visualization of...
Schrenk D, Bignami M, Bodin L, Chipman JK, Del Mazo J, Grasl-Kraupp B, Hogstrand C, Leblanc JC, Nielsen E, Ntzani E, Petersen A, Sand S, Schwerdtle T....In 2018, the EFSA Panel on Contaminants in the Food Chain (CONTAM) adopted a Scientific Opinion on the risks for animal health related to the presence of fumonisins, their modified forms and hidden forms in feed. A no observed adverse effect level (NOAEL) of 1 mg/kg feed was established for pigs. In poultry a NOAEL of 20 mg/kg feed and in horses a reference point for adverse animal health effect of 8.8 mg/kg feed was established, referred to as NOAEL. The European Commission (EC) requested EFSA to review the information regarding the toxicity of fumonisins for pigs, poultry and horses an...
Ferris RA, McCue PM, Borlee GI, Loncar KD, Hennet ML, Borlee BR.In this study, we evaluated the ability of the equine clinical treatments N-acetylcysteine, EDTA, and hydrogen peroxide to disrupt in vitro biofilms and kill equine reproductive pathogens (Escherichia coli, Pseudomonas aeruginosa, or Klebsiella pneumoniae) isolated from clinical cases. N-acetylcysteine (3.3%) decreased biofilm biomass and killed bacteria within the biofilms of E. coli isolates. The CFU of recoverable P. aeruginosa and K. pneumoniae isolates were decreased, but the biofilm biomass was unchanged. Exposure to hydrogen peroxide (1%) decreased the biofilm biomass and reduced the CF...
Dubey JP, Davis SW, Speer CA, Bowman DD, de Lahunta A, Granstrom DE, Topper MJ, Hamir AN, Cummings JF, Suter MM.Sarcocystis neuronan n. sp. is proposed for the apicomplexan taxon associated with myeloencephalitis in horses. Only asexual stages of this parasite presently are known, and they are found within neuronal cells and leukocytes of the brain and spinal cord. The parasite is located in the host cell cytoplasm, does not have a parasitophorous vacuole, and divides by endopolygeny. Schizonts are 5-35 microns x 5-20 microns and contain 4-40 merozoites arranged in a rosette around a prominent residual body. Merozoites are approximately 4 x 1 micron, have a central nucleus, and lack rhoptries. Schizonts...
