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.
Faccin M, Wiener DJ, Rech RR, Santoro D, Rodrigues Hoffmann A.The skin covers the external surface of animals, and it is constantly exposed to and inhabited by different microorganisms, including bacteria. Alterations in the skin barrier allow commensal and/or pathogenic bacteria to proliferate and penetrate deep into the lower layers of the skin. Being the first barrier to the external environment, the skin is prone to injuries, allowing the penetration of microorganisms that may lead to severe deep infections. Companion animals, especially dogs, are prone to bacterial infections, often secondary to allergic dermatitis. When environmental conditions are...
Martín-Faivre L, Gaudaire D, Laugier C, Bouraïma-Lelong H, Zientara S, Hans A.Equine arteritis virus (EAV) is an Alphaarterivirus (family Arteriviridae, order Nidovirales) that frequently causes an influenza-like illness in adult horses, but can also cause the abortions in mares and death of newborn foals. Once primary infection has been established, EAV can persist in the reproductive tract of some stallions. However, the mechanisms enabling this persistence, which depends on testosterone, remain largely unknown. We aimed to establish an in vitro model of non-cytopathic EAV infection to study viral persistence. In this work, we infected several cell lines originating f...
Occhiogrosso L, Capozza P, Buonavoglia A, Decaro N, Trotta A, Marin C, Corrente M.Equine periodontal disease (EPD) is a painful oral inflammatory syndrome characterized by multifactorial pathogenesis. Although it is well known that bacterial proliferation and consequent gingivitis are caused by the decomposition process of food residues, in hypsodont species, the pathogenetic role and the different bacterial species involved in the progression of EPD must be fully clarified. This study aimed to investigate the association of bacteria, including the complex red bacteria (RCB), with EPD, and to evaluate possible EPD risk factors. Bacterial species, including , , (belonging t...
Pusterla N, Kalscheur M, Peters D, Bidwell L, Holtz S, Barnum S, Lawton K, Morrissey M, Schumacher S.Little information is presently available regarding the frequency of the silent shedders of respiratory viruses in healthy sport horses and their impact on environmental contamination. Therefore, the aim of this study was to investigate the detection frequency of selected respiratory pathogens in nasal secretions and environmental stall samples of sport horses attending a multi-week equestrian event during the summer months. Six out of fifteen tents were randomly selected for the study with approximately 20 horse/stall pairs being sampled on a weekly basis. Following weekly collection for a to...
sub. (SEZ) is described as a commensal bacterium of several animal species, including humans. Growing evidence supports the potential role of SEZ in the onset and progression of severe clinical manifestations of diseases in horses and other animals. In the present communication, we describe the diagnostic procedure applied to characterize the streptococcal infections caused by a novel SEZ sequence type (ST525) in donkeys raised on a farm in Abruzzo, Italy. The diagnostic process began with anamnesis and anatomopathological analysis, which revealed a severe bacterial suppurative bronchopneumo...
Zakia LS, Arroyo LG, Gomez DE, Boerlin P, Surette MG, Lillie BN.Equine enterotyphlocolitis is an inflammatory process of the intestinal tract of horses that is associated with multiple etiologic agents and risk factors. Most clinical cases do not have an etiologic diagnosis. We describe here the pathogens detected and the histologic lesions found in horses with enterotyphlocolitis in Ontario that were submitted for postmortem examination, 2007-2019. We reviewed the medical records of 208 horses that fulfilled inclusion criteria. Cultures were positive in 67 of 208 (32%) equids for Clostridium perfringens, in 16 of 208 (8%) for Clostridioides difficile, and...
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 composition of the microbial and viral communities in addition to the pathogenic microorganisms is highly diverse in ticks, but the factors driving the diversity are not well understood. The tropical horse tick, , is distributed throughout the Americas and it is recognized as a natural vector of and , the causal agents of equine piroplasmosis. We characterized the bacterial and viral communities associated with partially-fed females collected by a passive survey on hors...
Ricard RM, Burton J, Chow-Lockerbie B, Wobeser B.Chlamydiae are reported to cause abortion in several species, however the association between Chlamydia sp. and equine abortions is poorly understood. A zoonotic transfer event of C. psittaci from aborted equine tissues in Australia has emphasized the need to better understand the prevalence of this pathogen in equine populations. The prevalence of chlamydia in equine abortions in North America has not been investigated thoroughly. We examined 99 formalin-fixed, paraffin-embedded placental samples submitted between 2009 and 2020 from equine abortions in Western Canada using chlamydia-specific ...
Plasil M, Oppelt J, Klumplerova M, Bubenikova J, Vychodilova L, Janova E, Stejskalova K, Futas J, Knoll A, Leblond A, Mihalca AD, Horin P.The major histocompatibility complex (MHC) with its class I and II genes plays a crucial role in the immune response to pathogens by presenting oligopeptide antigens to various immune response effector cells. In order to counteract the vast variability of infectious agents, MHC class I and II genes usually retain high levels of SNPs mainly concentrated in the exons encoding the antigen binding sites. The aim of the study was to reveal new variability of selected MHC genes with a special focus on MHC class I physical haplotypes. Long-range NGS to was used to identify exon 2-exon 3 alleles in th...
Suniga PAP, Mantovani C, Santos MG, Rieger JSG, Gaspar EB, Dos Santos FL, Mota RA, Chaves KP, Egito AA, Filho JCO, Nassar AFC, Dos Santos LR....Glanders is a contagious disease of equids caused by the Gram-negative bacterium Burkholderia mallei. In Brazil, the disease is considered to be reemerging and has been expanding, with records of equids with positive serology in most of the federative units. However, there are few reports describing the genotypic detection of the agent. This study demonstrated the detection of B. mallei by species-specific PCR directly from tissues or from bacterial cultures, followed by amplicon sequencing in equids (equines, mules, and asinines) with positive serology for glanders in all five geographic regi...
Afonso AC, Sousa M, Pinto AR, Cotovio M, Simões M, Saavedra MJ.As in human medicine, in veterinary medicine, chronic wounds are often related to polymicrobial infections and the presence of a biofilm, which compromises the effectiveness of therapeutic approaches. In this study, a Lusitano mare presented a 21-day-old chronic wound that was only being treated with an antiseptic. A swab sample was collected, and three isolates of Staphylococcus aureus and one of Pseudomonas aeruginosa were isolated. S. aureus did not show resistance to a panel of antibiotics. However, the P. aeruginosa isolate showed a resistance profile to carbapenems and fluoroquinolones, ...
Bookbinder LC, Mani R, Carr EA.Contemporary data reflecting local pathogens and their antibiograms is necessary to select empirical antimicrobial therapy for equine neonates. Objective: Describe bacterial isolates associated with equine neonatal infection and their antibiograms in the Midwestern United States. An increase in gram-positive infection and antibiotic resistance compared to previous literature was expected. Methods: Data from 149 fluid samples from 133 foals <30 days of age submitted for bacterial culture between January 2007 and December 2018. Methods: A retrospective evaluation of equine neonatal fluid cu...
Frisch V, Fuehrer HP, Cavalleri JV.In equine stables and their surroundings, a large number of insects are present that can be a nuisance to their equine hosts. Previous studies about dipterans transmitting infectious agents to Equidae have largely focused on Nematocera. For the preparation of this systematic review, the existing literature (until February 2022) was systematically screened for various infectious agents transmitted to Equidae via insects of the suborder Brachycera, including Tabanidae, Muscidae, Glossinidae and Hippoboscidae, acting as pests or potential vectors. The PRISMA statement 2020 (Preferred Reporting It...
Bernardino PN, Pusterla N, Conrad PA, Packham AE, Tamez-Trevino E, Aleman M, James K, Smith WA.Among the recognized neurologic diseases in horses, equine protozoal myeloencephalitis (EPM) has been reported around the world and still presents challenges in diagnosis and treatment. Horses can present with clinical neurologic signs consistent with EPM while testing negative for the two main causative agents, Sarcocystis neurona or Neospora hughesi, and may still be clinically responsive to anti-parasitic drug therapy. This context led to our hypothesis that another protozoal parasite, Toxoplasma gondii, which is known to cause toxoplasmosis in other mammalian species, is a potential pathog...
Eichenberger EM, Dent A, Hayes T, Woc-Colburn L.Streptococcus equi is an opportunistic pathogen in horses that has rarely been transmitted to humans. Here we present a zoonotic S. equi meningitis case in a kidney transplant recipient with exposure to infected horses. We discuss the patient's risk factors, clinical presentation, and management in the context of the limited literature on S. equi meningitis.
Mawhinney I, Bollard A.Detection of Taylorella equigenitalis (CEMO) in the horse uses genital swabs. These swabs traditionally have been put in Amies charcoal transport medium for detection by culture but are also used for PCR. We determined the suitability of swabs without transport medium (Dry swabs) for CEMO PCR compared to swabs in Amies charcoal transport medium. The experiment was a factorial design using swab type and dilution of organism in culture suspensions, done in two parts. Simulated genital swabs were prepared in the laboratory by dipping in pairs into culture suspensions containing T. equigenitalis w...
Bendlin A, Gemensky-Metzler AJ, Diaz-Campos D, Newbold GM, Miller EJ, Chandler HL.To compare results from a commercial next-generation sequencing (NGS) service to corneal cytology and culture for identification of causative organisms in veterinary patients presenting for infectious ulcerative keratitis (IUK). Methods: Swabs for corneal aerobic and fungal cultures and DNA swabs for NGS were submitted for canine and equine normal controls (n = 11 and n = 4, respectively) and IUK patients (n = 22 and n = 8, respectively) for which microbrush cytology specimens confirmed the presence of infectious organisms. The sensitivity of the NGS results was compared with bacterial...
Kawamura Y, Fujimoto Y, Kutsuna R, Tomida J, Yamamoto KI, Miyoshi-Akiyama T, Okuno M, Ogura Y, Matsuoka M, Kawaguchi T, Tsutsuki H, Sawa T.A Gram-stain-negative, spiral bacterium (PAGU 1991T) was isolated from the blood of a patient with diffuse large B-cell lymphoma. Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolate was very closely related to Helicobacter equorum LMG 23362T (99.1 % similarity), originally isolated from a faecal sample from a healthy horse. PAGU 1991T was also very closely related to PAGU 1750 in our strain library (=CCUG 41437) with 99.7 % similarity. Additional phylogenetic analyses based on the 23S rRNA gene sequence and GyrA amino acid sequence further supported the close rel...
Carnet F, Perrin-Cocon L, Paillot R, Lotteau V, Pronost S, Vidalain PO.Vaccination is one of the most widely used strategies to protect horses against pathogens. However, available equine vaccines often have limitations, as they do not always provide effective, long-term protection and booster injections are often required. In addition, research efforts are needed to develop effective vaccines against emerging equine pathogens. In this review, we provide an inventory of approved adjuvants for equine vaccines worldwide, and discuss their composition and mode of action when available. A wide range of adjuvants are used in marketed vaccines for horses, the main fami...
White RT, Jelocnik M, Klukowski N, Haque MH, Sarker S.Chlamydia psittaci is a zoonotic pathogen that infects birds, humans, and other mammals. Notably, recent studies suggested the human-to-human transmission of C. psittaci, and this pathogen also causes equine reproductive loss in Australia. Molecular studies in Australia to date have focused on and described clonal sequence type (ST)24 strains infecting horses, wild psittacine, and humans. In contrast, the genetic identity of C. psittaci strains from captive psittacine hosts is scarce. In 2022, C. psittaci was detected in the faeces of a healthy captive blue-fronted parrot (Amazona aestiva). Ge...
Rühl-Teichner J, Jacobmeyer L, Leidner U, Semmler T, Ewers C. is an opportunistic pathogen that causes severe infections in humans and animals, including horses. The occurrence of dominant international clones (ICs), frequent multidrug resistance, and the capability to form biofilms are considered major factors in the successful spread of in human and veterinary clinical environments. Since little is known about isolates from horses, we studied 78 equine isolates obtained from clinical samples between 2008 and 2020 for their antimicrobial resistance (AMR), clonal distribution, biofilm-associated genes (BAGs), and biofilm-forming capability. Based on ...
Poh KC, Cole ZT, Smarsh DN, Springer HR, Kelly K, Kenny LB, Machtinger ET.To evaluate the safety of repeated applications of permethrin concentrations (0% control, 1.5%, 5%, and 10%) to the necks and faces of horses and assess the efficacy and longevity of permethrin as an equine tick repellent. Methods: 5 healthy adult Quarter Horses. Methods: Each treatment was applied to the neck of each horse (0.01 m2) 4 times a day, for up to 10 days. An 8-mm biopsy was taken to evaluate postexposure dermal responses. Any treatments that were not withdrawn were applied to a quadrant of the horse's face 4 times a day, for up to 5 days. For tick bioassays, a treatment was applied...
Tang Z, Li X, Wang X, Zhang C, Zou L, Ren H, Liu W. () is one of the foremost pathogens responsible for diarrhea in foals. As antibiotic resistance increases, phages that specifically lyse bacteria are of great interest to us with regard to . In this study, a novel phage DCp1 was isolated from the sewage of a donkey farm. Phage DCp1 had a non-contractile short tail (40 nm in length) and a regular icosahedral head (46 nm in diameter). Whole-genome sequencing indicated that phage DCp1 had a linear double-stranded DNA genome with a total length of 18,555 bp and a G + C content of 28.2%. A total of 25 ORFs were identified in the genome, 6 of whic...
Scilimati N, Angeli G, Di Meo A, Dall'Aglio C, Pepe M, Beccati F.The radiographic, ultrasonographic, and scintigraphic findings of horses with thoracolumbosacral pain have been previously reported. In this study, the computed tomographic appearance of anatomical variations and pathological changes of the equine caudal lumbar region through a post-mortem examination were investigated. A total of 40 horses that had died or were submitted for euthanasia, for reasons unrelated to the study, were included in the study. From all the specimens, the modified vertebral system was adopted to evaluate and describe the four most caudal lumbar vertebrae, which were numb...
Ferreira PFA, Xavier JF, Nunes JF, Fonseca IP, de Mattos de Oliveira Coelho S, Soares de Souza MM, da Silva Coelho I.Livestock waste is widely used in agriculture. Although they provide benefits to the soil, and consequently to plants, they have the potential to contaminate the environment, as they contain pathogenic microorganisms and determinants of antimicrobial resistance, if not properly managed. Therefore, this study aims to evaluate the effect of composting horse bedding and poultry litter in organic and conventional production systems on the occurrence of bacteria in the Enterobacteriales order and to identify their antimicrobial resistance profiles. Bacterial strains were isolated from Salmonella-Sh...
Seo MG, Ouh IO, Kwak D.A clinical case of was reported for the first time in our previous study (2019) in a horse, a nondefinitive host. Although is a ruminant and not a zoonotic pathogen, it is responsible for persistent infections in horses. In this follow-up study, the prevalence of spp., including , was assessed in horse blood and lung tissue samples to fully understand spp. pathogen distribution and the potential risk factors of infection. Among 1696 samples, including 1433 blood samples from farms nationwide and 263 lung tissue samples from horse abattoirs on Jeju Island, a total of 29 samples (1.7%) teste...
Nwobi OC, Anyanwu MU, Jaja IF, Nwankwo IO, Okolo CC, Nwobi CA, Ezenduka EV, Oguttu JW.Staphylococcus aureus was isolated from a total of 360 nasal and groin skin swabs from 180 systematic randomly-selected horses slaughtered for meat at Obollo-Afor, Enugu State, Southeast Nigeria and antimicrobial, methicillin and heavy metal resistance profile and virulence potentials of the isolates established. Baird-Parker agar with egg yolk tellurite was used for S. aureus isolation. S. aureus isolates were confirmed biochemically and serologically using a specific S. aureus Staphytect Plus™ latex agglutination test kit. The antimicrobial resistance profile, methicillin, vancomycin and i...
Gosai F, Gosai N.Strangles is a contagious upper respiratory tract infection primarily affecting equines. It is rare disease with zoonotic transmission. It is caused by the bacterium, . We present the rare case of strangles in an elderly patient complicated by bacteraemia, osteomyelitis and native valve endocarditis. The patient was treated successfully with appropriate antibiotics and no surgical intervention was needed. In an age of accelerated emerging zoonosis, this is an important entity clinicians should be aware of to prevent delay in diagnosis and poor outcome. Conclusions: Strangles is a disease of eq...
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)...
Gehlen H, Klein KS, Merle R, Lübke-Becker A, Stoeckle SD.Evaluation of the role of indicator pathogens in equine surgical site infection (SSI) and other infection-promoting factors. Cross-sectional study. Horses presenting with an open injury or surgical colic during 1.5 years. A nasal swab and a faecal sample were collected from every patient upon admission. Furthermore, a wound swab was collected from wounds of injured horses. Details on the wounds and procedures were documented. Laparotomy incisions and injuries were monitored for signs suggesting infection. In total, 156 horses presented because of a surgical colic (n = 48) or open injuries (n...
Tripathi VN, Harding WC, Willingham-Lane JM, Hondalus MK.Rhodococcus equi is a facultative intracellular, Gram-positive, soilborne actinomycete which can cause severe pyogranulomatous pneumonia with abscessation in young horses (foals) and in immunocompromised people, such as persons with AIDS. All strains of R. equi isolated from foals and approximately a third isolated from humans contain a large, ~81-kb plasmid which is essential for the intramacrophage growth of the organism and for virulence in foals and murine in vivo model systems. We found that the entire virulence plasmid could be transferred from plasmid-containing strains of R. equi (dono...
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.
Silva RO, Ribeiro MG, Palhares MS, Borges AS, Maranhão RP, Silva MX, Lucas TM, Olivo G, Lobato FC.Toxin detection and screening could contribute to knowledge of the transmission patterns, risk factors and epidemiology of Clostridium difficile and Clostridium perfringens. Objective: To isolate C. difficile and C. perfringens and to detect A/B toxins in faecal samples from diarrhoeic and nondiarrhoeic foals. Methods: Cross-sectional observational study. Methods: A total of 153 samples from foals were collected: 139 samples from farms and 14 samples from diarrhoeic foals admitted to a veterinary hospital. The A/B toxins were detected by cytotoxicity assay. All suspected colonies of C. perfrin...
Scholz HC, Joseph M, Tomaso H, Al Dahouk S, Witte A, Kinne J, Hagen RM, Wernery R, Wernery U, Neubauer H.A polymerase chain reaction (PCR) assay targeting the flagellin P (fliP)-I S407A genomic region of Burkholderia mallei was developed for the specific detection of this organism in pure cultures and clinical samples from a recent outbreak of equine glanders. Primers deduced from the known fliP-IS407A sequence of B. mallei American Type Culture Collection (ATCC) 23344(T) allowed the specific amplification of a 989-bp fragment from each of the 20 B. mallei strains investigated, whereas other closely related organisms tested negative. The detection limit of the assay was 10 fg for purified DNA of ...
Garrett LA, Brown R, Poxton IR.This study compares quantitatively the microbiota of the gastrointestinal tract of healthy horses with that of horses with equine grass sickness (EGS). Faecal and ileal samples were cultured quantitatively on selective and non-selective media. Confirmed anaerobes were identified to species level. Overall faecal counts gave a ratio of aerobes:anaerobes of approximately 1:1. However, the mean counts in healthy horses of 4.4x10(8) aerobes:3.7x10(8) anaerobes per gram wet weight were different from counts in EGS (means were 10-100-fold higher), with statistically significant differences for the an...
Carman S, Rosendal S, Huber L, Gyles C, McKee S, Willoughby RA, Dubovi E, Thorsen J, Lein D.A study of acute respiratory disease in horses in Ontario was undertaken to determine the identity of current causative infectious agents. A nasopharyngeal swab was designed and utilized to maximize isolation of viruses, mycoplasma, and pathogenic bacteria. Serum samples were collected for parallel determination of antibody titers to equine influenza virus type A subtype 1 (H7N7) and subtype 2 (H3N8), equine rhinovirus types 1 and 2, equine herpesvirus type 1, Mycoplasma equirhinius, and Mycoplasma felis. Equine rhinovirus type 2 was recovered from 28/92 horses tested, and equine influenza vir...
Netherwood T, Wood JL, Townsend HG, Mumford JA, Chanter N.A case control study of foal diarrhoea in the United Kingdom was carried out over a 3-year period. Clostridium perfringens was significantly associated with foal diarrhoea (Odds Ratio (OR) = 3.0), being isolated from 57% of 421 animals with diarrhoea but from only 27% of 223 healthy foals. Also, C. perfringens was significantly associated with fatal diarrhoea (OR = 4.5). About half of diarrhoea with a fatal outcome was attributable to this organism. The other pathogens significantly associated with diarrhoea were rotavirus (OR = 5.6), Cryptosporidium spp. (OR = 3.2) and the nematode Strongyloi...
Lindahl SB, Aspán A, Båverud V, Paillot R, Pringle J, Rash NL, Söderlund R, Waller AS.Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) is generally considered a commensal and an opportunistic pathogen of the upper airways in horses. Establishing whether certain strains of S. zooepidemicus can cause upper respiratory disease as a host-specific pathogen of horses, and if there are certain genogroups of S. zooepidemicus that are more virulent than others is of major clinical importance. In this study, we describe an outbreak of upper respiratory disease in horses that was associated with S. zooepidemicus. Upper respiratory samples were cultured, analyzed by real-time PCR...
Gustafsson A, Båverud V, Gunnarsson A, Rantzien MH, Lindholm A, Franklin A.In Sweden there are several reports of mares developing acute colitis while their foals were being treated orally for Rhodococcus equi pneumonia with the combination of erythromycin and rifampicin. In this study 6 adult horses were given low oral dosages of these antibiotics, singly or in combination. Within 3 days post administration of erythromycin, in one case in combination with rifampicin, 2 horses developed severe colitis (one fatal). Clostridium difficile was isolated from one of the horses, whereas no specific pathogens were isolated from the other. Both horses had typical changes in b...
Research in microbiologyJanuary 14, 2016
Volume 167, Issue 4 313-324 doi: 10.1016/j.resmic.2016.01.001
Deredjian A, Alliot N, Blanchard L, Brothier E, Anane M, Cambier P, Jolivet C, Khelil MN, Nazaret S, Saby N, Thioulouse J, Favre-Bonté S.The occurrence of Stenotrophomonas maltophilia was monitored in organic amendments and agricultural soils from various sites in France and Tunisia. S. maltophilia was detected in horse and bovine manures, and its abundance ranged from 0.294 (±0.509) × 10(3) to 880 (±33.4) × 10(3) CFU (g drywt)(-1) of sample. S. maltophilia was recovered from most tested soil samples (104/124). Its abundance varied from 0.33 (±0.52) to 414 (±50) × 10(3) CFU (g drywt)(-1) of soil and was not related to soil characteristics. Antibiotic resistance properties of a set of environmental strains were ...
van Balen J, Mowery J, Piraino-Sandoval M, Nava-Hoet RC, Kohn C, Hoet AE.The role that environmental contamination might play as a reservoir and a possible source of Methicillin-resistant Staphylococcus aureus (MRSA) for patients and personnel at equine veterinary hospitals remains undefined, as the environment has only been monitored during outbreaks or for short periods. Therefore, the objectives of this study were to determine the monthly presence, distribution, and characteristics of environmental MRSA at an equine hospital, and to establish patterns of contamination over time using molecular epidemiological analyses. For this purpose, a yearlong active MRSA su...
Savu AN, Schoenbrunner AR, Politi R, Janis JE.Animal bites are common worldwide. Due to the plethora of animals, there are diverse pathogens with specific associated risks and treatment algorithms. It is crucial to understand these to develop and execute appropriate management plans. This practical review was designed to amalgamate the most common bites worldwide and synthesize data to help guide treatment plans. Methods: A PubMed literature search was performed focusing on the major animal bites. High-level studies were preferred and analyzed but lower-level studies were also used if high-level studies did not exist. Results: The tables ...
Passamonti F, Veronesi F, Cappelli K, Capomaccio S, Coppola G, Marenzoni ML, Piergili FD, Verini SA, Coletti M.Anaplasma phagocytophilum, the causative agent of granulocytic ehrlichiosis, affects several species of wild and domesticated mammals, including horses. In this work we compared direct and indirect methods to evaluate A. phagocytophilum presence in Central Italy: 135 sera were screened by IFA for A. phagocytophilum and other haemopathogens (Theileria equi and Babesia caballi). Each horse was also tested for A. phagocytophilum 16S rRNA with a nested-PCR technique. In order to examine the risk of A. phagocytophilum transmission, 114 ticks were examined for the presence of A. phagocytophilum by P...
Couto MA, Harwig SS, Lehrer RI.Equine neutrophil antimicrobial peptide 2 (eNAP-2), a recently described antimicrobial peptide isolated from equine neutrophils, was found to selectively inactivate microbial serine proteases (subtilisin A and proteinase K) without inhibiting mammalian serine proteases (human neutrophil elastase, human cathepsin G, and bovine pancreatic trypsin). Although the primary structure of eNAP-2 resembled that of several known antiproteases that belong to the 4-disulfide core peptide family, this pattern of selectivity is unique. eNAP-2 formed a noncovalent complex with native subtilisin A or proteinas...
Frey J.RTX toxins are bacterial pore-forming toxins that are particularly abundant among pathogenic species of Pasteurellaceae, in which they play a major role in virulence. RTX toxins of several primary pathogens of the family of Pasteurellaceae are directly involved in causing necrotic lesions in the target organs. Many RTX toxins are known as haemolysins because they lyse erythrocytes in vitro, an effect that is non-specific, but which serves as a useful marker in bacteriological identification and as an easily measurable signal in vitro in experimental studies. More recent studies have shown that...
Lin YZ, Shen RX, Zhu ZY, Deng XL, Cao XZ, Wang XF, Ma J, Jiang CG, Zhao LP, Lv XL, Shao YM, Zhou JH.The EIAV (equine infectious anemia virus) multi-species attenuated vaccine EIAV(DLV121) successfully prevented the spread of equine infectious anemia (EIA) in China in the 1970s and provided an excellent model for the study of protective immunity to lentiviruses. In this study, we compared immune responses induced by EIAV(DLV121) to immunity elicited by the virulent EIAV(LN40) strain and correlated immune responses to protection from infection. Horses were randomly grouped and inoculated with either EIAV(DLV121) (Vaccinees, Vac) or a sublethal dose of EIAV(LN40) (asymptomatic carriers, Car). C...
Nieri-Bastos FA, Lopes MG, Cançado PH, Rossa GA, Faccini JL, Gennari SM, Labruna MB.Adult ticks of the species Amblyomma parvum were collected from the vegetation in the Pantanal biome (state of Mato Grosso do Sul) and from horses in the Cerrado biome (state of Piauí) in Brazil. The ticks were individually tested for rickettsial infection via polymerase chain reaction (PCR) targeting three rickettsial genes, gltA, ompA and ompB. Overall, 63.5% (40/63) and 66.7% (2/3) of A. parvum ticks from Pantanal and Cerrado, respectively, contained rickettsial DNA, which were all confirmed by DNA sequencing to be 100% identical to the corresponding fragments of the gltA, ompA and ompB ge...
Grooters AM, Whittington A, Lopez MK, Boroughs MN, Roy AF.The purpose of this study was to evaluate the effects of sample handling, storage, and culture techniques on the isolation of Pythium insidiosum from infected equine tissues. Tissue and kunker samples obtained immediately posteuthanasia from a horse with subcutaneous pythiosis were used to assess the effects of sample type (kunkers vs. tissues), media type (selective vs. nonselective), storage technique, and storage time on P. insidiosum isolation rate. Overall, isolation rates were higher from fresh kunkers (94.6%) and stored kunkers (76.4%) than from fresh tissues (8.3%) or stored tissues (4...
Nadler SA, Carreno RA, Adams BJ, Kinde H, Baldwin JG, Mundo-Ocampo M.Phylogenetic relationships among six isolates of Halicephalobus gingivalis (Stefanski, 1954), a species with pathogenic potential in horses and humans, were evaluated using DNA sequences from the nuclear large-subunit ribosomal RNA (LSU rDNA) gene. Sequences from nematodes obtained from in vitro cultures (soil or clinical sources), or isolated from infected horse tissues, were compared. Gene sequences from a fatal equine clinical case from southern California and a free-living isolate recovered from southern California soil showed no fixed differences. Sequences from isolates representing two ...
Adler DMT, Damborg P, Verwilghen DR.Lameness is the most commonly reported health problem in horses, and lameness investigations which include local anaesthetic injections are routinely performed by equine practitioners. Through this process, bacteria can enter the tissues perforated by the needle and may cause local infections at the injection site. The objective of this in vitro study was to investigate if local anaesthetics at concentrations available in commercially available solutions could inhibit growth and/or kill bacteria that could be inoculated into the synovial space or soft tissues during injection. This study evalu...
Uzal FA, Arroyo LG, Navarro MA, Gomez DE, Asín J, Henderson E.Enteritis, colitis, and enterocolitis are considered some of the most common causes of disease and death in horses. Determining the etiology of these conditions is challenging, among other reasons because different causes produce similar clinical signs and lesions, and also because some agents of colitis can be present in the intestine of normal animals. We review here the main bacterial and viral causes of enterocolitis of horses, including Salmonella spp., Clostridium perfringens type A NetF-positive, C. perfringens type C, Clostridioides difficile, Clostridium piliforme, Paeniclostridium so...
Davis HA, Stanton MB, Thungrat K, Boothe DM.To describe bacteria isolated from reproductive tracts of mares and to examine the extent and patterns of resistance to antimicrobials commonly used for treatment of endometritis. Methods: Retrospective case series. Methods: 8,296 uterine swab, lavage, or biopsy samples obtained between January 2003 and December 2008 from 7,665 horses in central Florida. Methods: Results of bacterial culture and antimicrobial susceptibility testing were obtained for uterine swab, lavage, and biopsy samples collected from mares undergoing a routine breeding examination or examined because of a reproductive diso...
Sweeney CR, Holcombe SJ, Barningham SC, Beech J.Frequency of aerobic and anaerobic isolates in 327 aspirates and in 123 pleural fluid samples from 327 horses with pneumonia or pleuropneumonia and antimicrobial susceptibility patterns of the aerobes were reported. Of the 327 horses, 75% survived, 20% were euthanatized, and 5% died. Tracheobronchial aspirates or pleural fluid specimens from 25 of the horses did not yield growth. Of the remaining 302 horses, 221 had only aerobic organisms isolated, whereas only anaerobes were isolated from 6 of the 302 horses. The remaining 75 horses had mixed aerobic and anaerobic bacterial infections. The su...
Schein E, Rehbein G, Voigt WP, Zweygarth E.The vertebrate development of Babesia equi from infected Hyalomma marginatum in Morocco was investigated in vitro and in vivo. It was demonstrated that the sporozoites of B. equi initiate a phase of exo-erythrocytic schizogony in lymphocytes both in vitro and in vivo. On the other hand, sporozoites did not invade erythrocytes in vitro. The complete vertebrate life cycle of B. equi was simulated in vitro, from the invasion of lymphocytes by sporozoites, to the development of macro- and microschizonts, the invasion of erythrocytes by merozoites, and the subsequent intra-erythrocytic schizogony. ...
Lowe W, March JK, Bunnell AJ, O'Neill KL, Robison RA.Methods for the rapid detection and differentiation of the Burkholderia pseudomallei complex comprising B. pseudomallei, B. mallei, and B. thailandensis, have been the topic of recent research due to the high degree of phenotypic and genotypic similarities of these species. B. pseudomallei and B. mallei are recognized by the CDC as tier 1 select agents. The high mortality rates of glanders and melioidosis, their potential use as bioweapons, and their low infectious dose, necessitate the need for rapid and accurate detection methods. Although B. thailandensis is generally avirulent in mammals, ...
Forty seven working horses from Romania were post-mortem examined for small strongyles (Cyathostominae) infections. All horses were found infected. The overall cyathostomins intensity ranged from 390 to 13,010 and horses were infected by 8-24 species. The intensity was higher in ventral colon (1531) and dorsal colon (824), the lowest in the caecum (524). Twenty four species were identified. Cyathostomum catinatum, Cylicocyclus insigne, and C. Nassatus had 100% of prevalence. Over 50% of horses were infected by Coronocyclus coronatus, Cylicostephanus calicatus, C. goldi, and C. longibursatus. O...
Morrell JM, Klein C, Lundeheim N, Erol E, Troedsson MH.Bacteria (environmental contaminants and occasionally potential pathogens) are found in most stallion ejaculates and may negatively affect sperm quality during storage. Since the use of antibiotics can lead to the development of resistance, an alternative means of microbial control is desirable. The removal of bacteria from stallion semen using Single Layer Centrifugation through Androcoll-E was investigated. Known doses of cultured bacteria were added to freshly collected ejaculates (15mL aliquots) before processing by Single Layer Centrifugation. The resulting sperm pellets and controls (not...
Laus F, Preziuso S, Spaterna A, Beribè F, Tesei B, Cuteri V.An outbreak of strangle-like disease involving 26 horses farmed in central Italy was investigated by clinic examination, endoscopy, cytology, bacteriology and polymerase chain reaction (PCR). At weekly interval, a total of three nasal swabs and one guttural pouches lavage fluid (GPLF) were collected, and no Streptococcus equi subsp. equi carrier was found. Some horses showed upper airways disease and endoscopic signs of pharyngeal lymphoid hyperplasia of different grade and/or abnormal endoscopic appearance of guttural pouches. Streptococcus dysgalactiae subsp. equisimilis was isolated from 14...
Ellis WA, O'Brien JJ, Cassells JA, Montgomery J.Thirteen strains of pathogenic leptospires were isolated from 12 of 91 horses; seven strains belonged to the Australis serogroup (serotype bratislava) with three, two and one strains belonging to the Icterohaemorrhagiae, Hebdomadis (serotype hardjo) and Autumnalis serogroups respectively. Using leptospires isolated from horses and others representing the known parasitic Leptospira serogroups, a sample of 650 mares' sera was tested for agglutinating antibodies. Antibodies were found in 89.1 per cent of sera. The predominant reaction was to serotype bratislava, strain S/1334/79, isolated in this...
Gingrich JB, Williams GM.Paucity of data on host-feeding patterns and behavior of 43 mosquito species that are reported as suspected West Nile virus (WN) vectors has limited full evaluation of their vectorial capacity. Recent studies addressing this issue need additional confirmation and should also be expanded to include collections of species or subpopulations attracted to humans. We used 4 types of collection methods to collect mosquitoes, including omnidirectional Fay-Prince traps, Centers for Disease Control-type light traps, gravid traps, and human-landing collections. Mosquitoes were collected during 2 full WN ...
