Equi Infection Research Articles

Molecular detection of equid herpesvirus in bronchoalveolar lavage fluid from asymptomatic horses in Southern Brazil.

Molecular approaches to diagnose respiratory viruses have provided an opportunity for early and subclinical pathogen detection, particularly in samples from the upper respiratory tract. This study aimed to investigate the presence of herpesviruses, particularly equid herpesvirus (EHV)-2 and EHV-5, in samples from the lower respiratory tract of healthy racehorses from Southern Brazil. Samples from the lower respiratory tract (i.e., bronchoalveolar lavage fluid [BALF]) were assessed by video endoscopy, cytological evaluation of BALF, and tracheal aspirates (TA), along with quantitative polymerase chain reaction (qPCR), to detect equine herpesvirus infection in the lower respiratory tract samples and compare corresponding cytological and endoscopic findings. At least one abnormality per horse during endoscopy examination was observed, including, but not limited to, mucous secretion in the airways and pharyngeal lymphoid hyperplasia. The presence of EHV-2 and/or EHV-5 was detected by qPCR in 3/10 animals. One horse was positive for EHV-2 alone, one for EHV-5 alone, and one for both. To the authors' knowledge, this is the first molecular detection of EHV-2 and EHV-5 in Brazilian thoroughbred horses. These findings may provide new insights into the epidemiology of EHV-2 and EHV-5 in Brazilian horses, evidencing the importance of the molecular investigation, early detection, and prevention of respiratory diseases.

Seroprevalence of SARS-CoV-2 in 1186 Equids Presented to a Veterinary Medical Teaching Hospital in California from 2020 to 2022.

While some companion animals have been shown to be susceptible to SARS-CoV-2, their role in the COVID-19 pandemic has remained poorly investigated. Equids are susceptible to SARS-CoV-2 based on the similarity of the human ACE-2 receptor and reports of infection. Clinical disease and prevalence factors associated with SARS-CoV-2 infection in equids have not yet been investigated. The aim of this study was to determine the seroprevalence of SARS-CoV-2 and selected prevalence factors in 1186 equids presented for various conditions to a Veterinary Medical Teaching Hospital over a two-year period. Blood samples were tested for SARS-CoV-2 antibodies using an ELISA targeting the receptor binding domain (RBD) of the SARS-CoV-2 spike protein. Further, selected prevalence factors (season, age, breed, sex, presenting complaint) were retrieved from the medical records. No information was available on whether the horses had come into contact with COVID-19-positive individuals. Among the study animals, 42/1186 (3.5%) horses had detectable SARS-CoV-2 antibodies. Amongst the prevalence factors investigated, only seasonality (spring) was associated with a greater frequency of seropositivity to SARS-CoV-2. Horses with medical and surgical complaints were more likely to test seropositive to SARS-CoV-2 compared to horses presented for routine health care procedures, suggesting more frequent and/or longer interactions with individuals with COVID-19. While horses can become infected with SARS-CoV-2 via the occasional spillover from COVID-19 individuals, clinical disease expression remains subclinical, making horses an unlikely contributor to the spread of SARS-CoV-2.

Plasma metabolome of healthy and Rhodococcus equi-infected foals over time.

Foals that develop pulmonary ultrasonographic lesions on Rhodococcus equi (R. equi) endemic farms are treated with antibiotics because those at risk of developing clinical pneumonia (~20%) cannot be recognised early. Candidate biomarkers identified using metabolomics may aid targeted treatment strategies against R. equi. (1) To describe how foal ageing affects their plasma metabolome (birth to 8 weeks) and (2) to establish the effects that experimental infection with Rhodococcus equi (R. equi) has on foal metabolome. Experimental study. Nine healthy newborn foals were experimentally infected with R. equi as described in a previous study. Foals were treated with oral antibiotics if they developed clinical pneumonia (n=4, clinical group) or remained untreated if they showed no signs of disease (n=5, subclinical group). A group of unchallenged foals (n=4) was also included in the study. By the end of the study period (8 weeks), all foals were free of disease. This status was confirmed with transtracheal wash fluid evaluation and culture as well as thoracic ultrasonography. Plasma metabolomics was determined by GC-MS weekly for the study duration (8 weeks). Foals' plasma metabolome was altered by ageing (birth to 8 weeks) and experimental infection with R. equi as demonstrated using multivariate statistical analysis. The intensities of 25 and 28 metabolites were altered by ageing and infection (p < 0.05) respectively. Furthermore, 20 metabolites changed by more than 2-fold between clinical and subclinical groups. The number of foals is limited. Foals were experimentally infected with R. equi. Ageing and R. equi infection induced changes in the plasma metabolome of foals. These results provide an initial description of foal's plasma metabolome and serve as background for future identification of R. equi pneumonia biomarkers.

Less Typical Courses of Rhodococcus equi Infections in Foals

This article aims to present several interesting and less typical courses of Rhodococcus equi infections in foals, collected during the 2019-2021 foaling seasons in some Polish studs. The study was conducted by the Division of Veterinary Epidemiology and Economics, Warsaw University of Life Sciences-SGGW, and concentrated on ultrasonographic contribution to diagnostics and treatment of the disease. Among many standard cases of rhodococcal pneumonia, some rare ones occurred. The aforementioned issues include the potential contribution of rhodococcal infection to a grave outcome in a prematurely born filly, lost as a yearling, so-called "extrapulmonary disorders" (EPD), a hypothesis of inherited immunodeficiency with grave outcome in a breeding dam line from one stud, and macrolide-induced anhidrosis. The main benefit of this report would be to supplement the general picture of clinical rhodococcosis.

Seroprevalence and risk factors associated with equine infectious anemia in the state of Goiás, Brazil

Equine infectious anemia (EIA) is an infectious disease affecting equine in most countries and represents a notifiable disease with compulsory euthanasia of positive animals. The present study aimed to determine the prevalence of EIAV infected equines in herds of the state of Goiás (Central Brazil) and to evaluate the risk factors associated with the occurrence of the disease. Blood samples were collected from 1170 equids from 332 randomly selected farms divided into three different strata according to their herd characteristics. Also, an epidemiological questionnaire was applied during the visit to the farm. Of the 332 farms evaluated, 12 (3.1%; 95% CI: 1.24 – 6.00) had at least one positive equine for EIA, and of the 1170 evaluated equines, 14 (2%; 95% CI: 0.31–3.00) were positive in agar gel immunodiffusion. Multivariate analysis revealed that the use of a vaccination pistol (p < 0.001) and the presence of water bodies inside the farm (p < 0.01) were risk factors associated with the occurrence of EIA. Thus, the present study demonstrated a low but widespread prevalence of EIAV infected animals in the herds of Goiás state and that iatrogenic and environmental risk factors were associated with the occurrence of the disease.

Disease progression, pathologic, and virologic findings of an equine influenza outbreak in rescue donkeys.

Equine influenza virus is a common cause of respiratory disease in equids. Few reports describe clinical presentation and disease progression in donkeys. Describe the clinical and diagnostic findings, outcome, and pathologic lesions associated with influenza pneumonia in donkeys. Thirteen unvaccinated donkeys ranging from 1week to 12 years of age and sharing clinical signs and exposure history. Retrospective case series. Medical records from June to July 2020 at the Colorado State Veterinary Teaching Hospital and collaborating referring veterinary practices were reviewed. The diagnosis was confirmed by molecular testing, virus isolation, and partial genetic and phylogenetic analysis of the virus. Survival in donkeys <1 year old was 16.6% (1/6) whereas survival in animals >1 year of age was 85.7% (6/7). Hemagglutinin gene sequencing and phylogenetic analysis confirmed a contemporary clade 1 Florida sublineage H3 virus as the causative agent. Clinical signs of equine influenza virus infection in donkeys are similar to those observed in horses. Prognosis for survival generally is good, but deaths have been observed especially in foals born to seronegative dams. This finding emphasizes the importance of prenatal vaccination protocols in all equids, including donkeys.

Reflecting on the 11th International Equine Infectious Diseases Conference.

Julia Kydd, Martin Nielsen and Andrew Waller highlight some of the key presentations given at last year's 11th International Equine Infectious Diseases Conference, which was held virtually.

Dose-Dependent Hepacivirus Infection Reveals Linkage between Infectious Dose and Immune Response.

ABSTRACTMore than 70 million people worldwide are still infected with the hepatitis C virus 30 years after its discovery, underscoring the need for a vaccine. To develop an effective prophylactic vaccine, detailed knowledge of the correlates of protection and an immunocompetent surrogate model are needed. In this study, we describe the minimum dose required for robust equine hepacivirus (EqHV) infection in equids and examined how this relates to duration of infection, seroconversion, and transcriptomic responses. To investigate mechanisms of hepaciviral persistence, immune response, and immune-mediated pathology, we inoculated eight EqHV naive horses with doses ranging from 1–2 copies to 1.3 × 106 RNA copies per inoculation. We characterized infection kinetics, pathology, and transcriptomic responses via next generation sequencing. The minimal infectious dose of EqHV in horses was estimated at 13 RNA copies, whereas 6 to 7 copies were insufficient to cause infection. Peak viremia did not correlate with infectious dose, while seroconversion and duration of infection appeared to be affected. Notably, seroconversion was undetectable in the low-dose infections within the surveillance period (40 to 50 days). In addition, transcriptomic analysis revealed a nearly dose-dependent effect, with greater immune activation and inflammatory response observed in high-dose infections than in low-dose infections. Interestingly, inoculation with 6–7 copies of RNA that did not result in productive infection, but was associated with a strong immune response, similar to that observed in the high-dose infections.IMPORTANCE We demonstrate that the EqHV dose of infection plays an important role for inducing immune responses, possibly linked to early clearance in high-dose and prolonged viremia in low-dose infections. In particular, pathways associated with innate and adaptive immune responses, as well as inflammatory responses, were more strongly upregulated in high-dose infections than in lower doses. Hence, inoculation with low doses may enable EqHV to evade strong immune responses in the early phase and therefore promote robust, long-lasting infection.

Use of recombinant calflagin protein as a potential candidate for diagnosis of Trypanosoma evansi infection

Serodiagnosis of surra, caused by Trypanosoma evansi, is still based on native antigens purified from bloodstream form of T. evansi grown in rodents. In order to investigate prospective diagnostic possibilities as an alternative for native antigens, we cloned, expressed 26 kDa calflagin protein containing 218 amino acids from T. evansi (Indian Strain) in Escherichia coli. The potential of recombinant calflagin (rCLF) protein as diagnostic antigen was evaluated in immunoblot and indirect ELISA using experimentally infected equine serum samples from 0 to 84 days post infection. The antibodies against T. evansi were detected with rCLF antigen in serum samples of experimentally infected equines as early as 10 days and 14 days post infection, using immunoblot and ELISA respectively. No cross-reactivity was observed with rCLF antigen in ELISA with different serum samples of equines positive for Equine herpesvirus 1, Burkholderia mallei, and Theileria equi infections. Several immunoreactive regions ranging from 10 to 28 kDa were detected using distinct T. evansi isolates (pony, cattle, donkey and camel origin) indicating presence of multiple calflagin family members in a single trypanosome. Indirect immunofluorescence antibody test with anti-CLF rabbit hyperimmune serum showed localisation of native immunogenic protein near attachment of flagellum. The rCLF protein was found to be a potential diagnostic candidate for distinguishing T. evansi positive and negative equine serum sample, suggesting that it could be used for serological surveys in animals for surra. In addition, it could be used with other potential diagnostic candidates to improve the diagnostic efficiency.

Population structure and genomic footprints of selection in five major Iranian horse breeds.

The genetic structure and characteristics of Iranian native breeds are yet to be comprehensibly investigated and studied. Therefore, we employed genomic information of 364 Iranian native horses representing the Asil (n=109), Caspian (n=40), Dareshuri (n=44), Kurdish (n=95), and Turkoman (n=76) breeds to reveal the genetic structure and characteristics. For these and 19 other horse breeds, principal component analysis, Bayesian model-based, Neighbor-Net, and bootstrap-based TreeMix approaches were applied to investigate and compare their genetic structure. Additionally, three haplotype-based methods including haplotype homozygosity pooled, integrated haplotype score, and number of segregating sites by length were applied to trace genomic footprints of selection of Asil, Caspian, Dareshuri, Kurdish, and Turkoman groups. Then, the Mahalanobis distance based on the negative-log10 rank-based P-values was estimated based on the haplotype homozygosity pooled, integrated haplotype score, and number of segregating sites by length values. Asil, Caspian, Dareshuri, Kurdish, and Turkoman can be categorized into five different genetic clusters. Based on the top 1% of Mahalanobis distance based on the negative-log10 rank-based P-values of SNPs, we identified 24 SNPs formerly reported to be associated with different traits and >100 genes undergoing selection pressures in Asil, Caspian, Dareshuri, Kurdish, and Turkoman. The detected QTL undergoing selection pressures were associated with withers height, equine metabolic syndrome, overall body size, insect bite hypersensitivity, guttural pouch tympany, white markings, Rhodococcus equi infection, jumping test score, alternate gaits, and body weight traits. Our findings will aid to have a better perspective of the genetic characteristics and population structure of Asil, Caspian, Dareshuri, Kurdish, and Turkoman horses as Iranian native horse breeds.

Molecular occurrence and risk factors for Toxoplasma gondii infection in equids in Jilin, China

Toxoplasma gondii, one of the important zoonotic parasites, has been detected in lots of hosts including humans, with a widespread prevalence. The products of equids, such as meat and milk, have been closely related to humans’ life. As the intermediate hosts, little is known about equids toxoplasmosis in Jilin province. Therefore, the present study aimed to evaluate the occurrence and risk factors of Toxoplasma gondii infections in equids from Jilin, northeastern China. In this study, a total of 245 blood samples of equids (192 horses, 25 donkeys and 28 mules) were collected from six localities in Jilin Province from March 2018 to August 2020 and detected by PCR. The occurrence rate of T. gondii B1 gene was analyzed using multivariable logistic regression to evaluate risk factors associated with the positive rates in equids. Among 245equids, T. gondii molecular occurrence was 9.0% (22/245). The highest positive rate was observed in equids from Dongfeng (16.3%) followed by Taonan (10.0%), Wangqing (8.3%), Antu (8.0%), Tonghua (8.0%) and Shulan (2.3%). Statistical analysis revealed that farming model and region may be two main risk factors. Data analysis indicated that the positive rate in captive farm (3.2%, 95% CI: 0.0–6.7%) was significantly lower than those in cage-free farm (P < 0.05), and the region of Shulan was protective factor (OR: 0.063, 95% CI: 0.007–0.559).The results of our study alert people to be aware that the present of equids T. gondii infection in this region, and contribute to a prevention and treatment program for toxoplasmosis in Jilin, China.

Equine piroplasmosis in northern Algeria: Haematological and serological parameters

Equine piroplasmosis is an acute, subacute or chronic tick-borne disease due to Babesia caballi and/or Theileria equi, affecting Equidae and causing economic losses to horse breeders and poor performances during tournaments. The objectives were fourfold: first to determine the seroprevalence of piroplasmosis in horses via cELISA, second to establish the haematological profile of piroplasmosis in horses of different Algerian areas through optical microscopy, third to identify the risk factors associated with the infection, and forth to try to elucidate any eventual correlation between piroplasmosis and anaemia. The study was carried out in different regions of northern Algeria. A total of 182 horses of both sexes were blood tested to estimate the prevalence of Theileria equi and Babesia caballi via competitive ELISA and to examine microscopically thin stained blood smears looking for haematological alterations using a standard cell counter. Parasites were detected in 42.9% of horses after microscopic examination of thin blood smears. The seroprevalence of equine piroplasmosis infection using competitive ELISA was 39% and 1,1% for Theileria equi and Babesia caballi respectively. Therefore, equine piroplasmosis is present in different regions of Algeria with a predominance of positivity in the central region (54,5%). Season (winter), region (central) and intended activity are the risk factors significantly associated with the prevalence of the disease. Anaemia was observed in 34,61% of individuals but there was no significant differences between positive and negative populations. Piroplasmosis is endemic in Algeria. Measures such as limiting horses’ mobility should be taken to reduce/prevent dissemination

Tumor necrosis factor signaling during equine placental infection leads to pro-apoptotic and necroptotic outcomes

Ascending placentitis is the leading cause of abortion in the horse. The pleiotropic cytokine tumor necrosis factor (TNF) is an upstream regulator of this disease, but little is understood regarding its function in pregnancy maintenance or placental infection. To assess this, RNA sequencing was performed on chorioallantois and endometrium of healthy pregnant mares at various gestational lengths (n = 4/gestational age), in addition to postpartum chorioallantois, and diestrus endometrium to assess expression of TNF, TNFR-1, and TNFR-2. Additionally, ascending placentitis was induced via trans-cervical inoculation of S. equi spp. zooepidemicus in pregnant mares (n = 6 infected / n = 6 control) and tissues and serum were collected to evaluate TNF-related transcripts. IHC was performed to confirm protein localization of TNFR-1 and TNFR-2. In healthy pregnancy, TNFR-1 appears to be the predominant TNF-related receptor. Following induction of disease, TNF concentrations increased in maternal serum, but expression did not alter at the tissue level. While both TNFR-1 and TNFR-2 increased following induction of disease, alterations in downstream pathways indicate that TNFR-1 is the dominant receptor in ascending placentitis, and is primarily activated within the chorioallantois, with minimal signaling occurring within the endometrium. In conclusion, TNF appears to be involved in the pathophysiology of ascending placentitis. An increase in this cytokine during disease progression is believed to activate TNFR-1 within the chorioallantois, leading to various pro-apoptotic and necroptotic outcomes, all of which may signal for fetal demise and impending abortion.

Fatal Infection in an Alpaca (Vicugna pacos) Caused by Pathogenic Rhodococcus equi

Simple SummarySerious consequences of septicemic bacterial infections include the formation of purulent and pyogranulomatous inflammation resulting in abscesses in inner organs. Different bacteria are known to cause these infections in livestock. In this study, we report in detail on a case of a fatal Rhodococcus (R.) equi infection in an alpaca (Vicugna pacos), to our knowledge, for the first time. R. equi is a member of the actinomycetes, a bacterial group known to contain several pathogenic bacteria. R. equi primarily affects equine foals and other domestic animals, but also humans, which renders this bacterium a zoonotic agent. The rhodococcal infection of the alpaca reported herein caused septicemia, resulting in emaciation and severe lesions in the lungs and heart. The onset of infection was presumably caused by aspiration pneumonia, resulting in abscesses exclusively in the lungs. The R. equi isolate proved to be pathogenic, based on the virulence gene vapA encoding the virulence-associated protein A. Antibiotic susceptibility testing revealed a susceptibility to doxycycline, erythromycin, gentamycin, neomycin, rifampicin, trimethoprim/sulfamethoxazole, tetracycline and vancomycin. This report of an R. equi infection in an alpaca makes clear that we still have knowledge gaps about bacterial infectious diseases in alpacas and potential zoonotic impacts. Therefore, the determination of pathogenic, zoonotic bacteria in alpacas is essential for treatment and preventive measures with respect to sustaining the health, welfare and productivity of this camelid species.Rhodococcus (R.) equi is a pathogen primarily known for infections in equine foals, but is also present in numerous livestock species including New World camelids. Moreover, R. equi is considered an emerging zoonotic pathogen. In this report, we describe in detail a fatal rhodococcal infection in an alpaca (Vicugna pacos), to our best knowledge, for the first time. The alpaca died due to a septicemic course of an R. equi infection resulting in emaciation and severe lesions including pyogranulomas in the lungs and pericardial effusion. The onset of the infection was presumably caused by aspiration pneumonia. R. equi could be isolated from the pyogranulomas in the lung and unequivocally identified by MALDI-TOF MS analysis and partial sequencing of the 16S rRNA gene, the 16S-23S internal transcribed spacer (ITS) region and the rpoB gene. The isolate proved to possess the vapA gene in accordance with tested isolates originating from the lungs of infected horses. The R. equi isolates revealed low minimal inhibitory concentrations (MIC values) for doxycycline, erythromycin, gentamycin, neomycin, rifampicin, trimethoprim/sulfamethoxazole, tetracycline and vancomycin in antibiotic susceptibility testing. Investigations on the cause of bacterial, especially fatal, septicemic infections in alpacas are essential for adequately addressing the requirements for health and welfare issues of this New World camelid species. Furthermore, the zoonotic potential of R. equi has to be considered with regard to the One Health approach.

Novel Quantitative PCR for Rhodococcus equi and Macrolide Resistance Detection in Equine Respiratory Samples.

Simple SummaryMultidrug-resistant (MDR) Rhodococcus equi (R. equi) is rapidly spreading across the US in equine breeding farms, causing devastating untreatable disease in foals. There is a critical need for new diagnostic tools that can identify R. equi and its antibiotic resistance profile accurately and fast. This project aimed to develop and standardize a novel multiplex quantitative real-time PCR (qPCR) to detect R. equi and its most clinically relevant antimicrobial resistance genes directly from equine respiratory samples. We have designed three pairs of oligos (a.k.a primers or oligonucleotides) to identify R. equi and MLSB (macrolide, lincosamide, streptogramin B) resistance genes erm(46) and erm(51) that can be used in single-plex and multiplex qPCR assays. Furthermore, our new qPCR shows high sensitivity and specificity in in-silico analysis and when tested in mock equine respiratory samples. Therefore, we believe it can be used for a fast-preliminary diagnosis of R. equi and the simultaneous prediction of its most critical resistant profile. The new molecular diagnostic tool presented here will shorten the waiting time from the moment the practitioner sees the equid patient until it is diagnosed and appropriately treated.R. equi is an important veterinary pathogen that takes the lives of many foals every year. With the emergence and spread of MDR R. equi to current antimicrobial treatment, new tools that can provide a fast and accurate diagnosis of the disease and antimicrobial resistance profile are needed. Here, we have developed and analytically validated a multiplex qPCR for the simultaneous detection of R. equi and related macrolide resistance genes in equine respiratory samples. The three sets of oligos designed in this study to identify R. equi housekeeping gene choE and macrolide resistance genes erm(46) and erm(51) showed high analytic sensitivity with a limit of detection (LOD) individually and in combination below 12 complete genome copies per PCR reaction, and an amplification efficiency between 90% and 147%. Additionally, our multiplex qPCR shows high specificity in in-silico analysis. Furthermore, it did not present any cross-reaction with normal flora from the equine respiratory tract, nor commonly encountered respiratory pathogens in horses or other genetically close organisms. Our new quantitative PCR is a trustable tool that will improve the speed of R. equi infection diagnosis, as well as helping in treatment selection.

A review of endo and ecto parasites of equids in Iraq

This article briefly reviews most studies in Iraq, and expressed common zoonotic and non-zoonotic parasites. Currently, protozoa, helminthes, hard and soft ticks have been properly reported, as a result of a large number of parasites were described and distributed in all Iraq. The protozoa frequently recorded included species belonging to the genera: Toxoplasma, Theileria, Babesia, plasmodium, Anaplasma, Microfilaria, cryptosporidium, giardia, Eimeria, Balantidium and Entamoeba. The helminths frequently reported of different of the genera: Dicrocoelium, Habronema, Echinococcus, Dictyocaulus, Trichostrongylus, Parascaris, Oxyuris, Cyathostomum, Anoplocephala, Setaria and Fasciola can affected all categories of equines, whether on grass or stabled. Also, hard, soft ticks and Sarcoptes were the only ectoparasites frequently recorded. Parasitic fly species of the genera Gasterophilus were also recorded. Parasitic infections of equines in Iraq are frequent and caused by a diversity of parasites, which threatens the health and causes major economic losses. Infected equines with piroplasms are suffering from specific clinical signs: (emaciation, fever, pale mucosal membranes, jaundice, colic and diarrhoea) in addition companied with anemia, leukocytosis and hyperbilirubinemia. The parasitic infections associated with the several risk factors (age, gender, activity, location and season) and more risky in zoonotic parasites to horsemen. All treatment for the parasitic infections should be through the intramuscular route except ivermectin orally. Control of vector and make further researches depend on modern methods not only coprological examinations to identify distributed species and chronic infections.

Dynamics of Theileria equi Infection in Rhipicephalus (Boophilus) microplus during the Parasitic Phase in a Chronically Infected Horse.

Experimental studies have demonstrated that Rhipicephalus (Boophilus) microplus transmits Theileria equi to horses. However, the degree and dynamics of this protozoan infection in the vector’s organism have not been fully elucidated. Therefore, this study aimed to evaluate the infection rate and parasitic load of T. equi in R. (B.) microplus, the infection dynamics in this arthropod during experimental infestation in a horse chronically infected with T. equi, and to evaluate the trans-stadial and intrastadial transmission competence of T. equi by R. (B.) microplus. The experimental infestation period of R. (B.) microplus on the horse was 33 days, but males were found on the animal up to 60 days post-infestation. After the fifth day post-infestation, ticks and equine blood were collected every two days. Whole ticks from the same developmental stage collected in the same day were pooled. Adult ticks were dissected to extract salivary glands and gut. DNA extraction was performed for all the samples, and they were then submitted to qPCRs for T. equi diagnosis. Freshly molted nymphs collected as larvae in the horse and freshly molted males and females collected as nymphs in the horse showed equal to or greater than 75% positivity for T. equi, indicating a strong possibility of trans-stadial transmission. The longest permanence of the male ticks on the horse associated with the high positivity rate of this type of sample for T. equi indicate that the male may play a role in the intrastadial transmission of T. equi to infection-free horses. The salivary glands displayed 77.78% positivity for T. equi and presented a higher infection rate at the end of the experimental period (100% from 29 to 33 days post-infection). This study shows that R. (B.) microplus has high T. equi infection rates and that the infection rate and parasitic load increased over the experimental period. These findings confirm the importance of chronically infected horses with T. equi as a source of infection for R. (B.) microplus.

Characterization and identification of bacterial flora from infected equine hooves

Background: The aim of this study was to characterize and identify the bacterial flora associated with a specific hoof infection in a population of horses in the Rochester NY area. Methods: Samples taken from horses showing symptoms of infection were first grown on a Brain-Heart Infusion (BHI) solid medium. Forty different bacterial colonies were obtained and characterized microscopically and biochemically. The identity of these bacteria was also confirmed by 16S ribosomal DNA sequencing. Results: We have identified normal inhabitants of the skin such as Staphylococcus epidermidis as well as bacteria of the genus Bacillus commonly found in soil. In addition, bacteria such as Enterococcus gallinarum and Lactobacillus normally found in the intestinal tract of mammals were recovered. Interestingly, Corynebacterium xerosis, which is known to cause animal diseases was also isolated from infected horses. Conclusions: Our results indicate that the infection affecting the horses is likely the result of the presence of multiple bacterial genera including members of the normal skin and gut flora, as well as soil bacteria.

Comparative Studies on the Antioxidant, Antifungal, and Wound Healing Activities of Solenostemma arghel Ethyl Acetate and Methanolic Extracts

Various herbal compounds are used for medical purposes due to their safety, as there are no or minimal side effects. This study was performed to assess the wound healing and antioxidant activities of ethyl acetate (EtOAc) and methanolic extract (MeoH) of Solenostemma arghel (S. arghel). Their antifungal activities were also evaluated against isolated swabs of equine wounds. They underwent GC-MS analysis for the characterization of both extracts. For wound healing evaluation, forty-five male albino rats were divided into three groups; the control group was treated with normal saline, and the other two groups were treated with S. arghel EtOAc and MeoH extract gels, respectively. The wounds were examined clinicopathologically and immunohistochemistry on the 3rd, 7th, and 14th days post-wounding. GC-Ms analysis of S. arghel recorded fifty-one volatile organic compounds (VOCs) within EtOAc extraction and thirty VOCs in MeoH extract. VOCs represented in EtOAc extract showed higher antioxidant activity and better and faster wound healing than VOCs of MeOH extract. The treated groups showed improved wound healing clinically and pathologically in comparison with the control group as they decreased the wound surface area (WSA) and percent (WSA%) and increased the wound contraction percent (WC%), epithelization, fibroblast proliferation with neovascularization, and reduced the inflammatory reaction. Moreover, the treated groups showed higher expression of vascular endothelial growth factor (VEGF) compared with the control. The EtOAc extract showed higher antifungal activity against Penicillium funiculosum, P. jensenii, M. cinctum, and Candida albicans, which were isolated from infected clinical equine wounds, than MeOH extract. The treated groups showed improved wound healing clinically and pathologically in comparison with the control group as they decreased the wound surface area (WSA) and percent (WSA%) and increased the wound contraction percent (WC%), epithelization, fibroblast proliferation with neovascularization, and reduced the inflammatory reaction. Moreover, the treated groups showed higher expression of vascular endothelial growth factor (VEGF) compared with the control. Additionally, the two extract gels showed promising healing of equine wounds. In conclusion, the study recommended the use of S. arghel EtOAc extract as it was proven to promote wound healing compared with MeoH extract.

Culturable Microbial Population From the Upper Respiratory Tract of 1,010 Clinically Healthy Horses in Southern Brazil

Microbiological diagnosis of equine respiratory infections is essential for disease management. However, reliable diagnosis can be a challenge due to colonization of the upper respiratory tract (URT) by a diverse microbial population, and because there is a lack of studies with samples from healthy animals. Aiming to guide adequate URT culture, this work reports culturable microbial population from the URT of 1,010 apparently healthy horses from 341 farms in Southern Brazil and identifies the putative presence of pathogenic microorganisms. Nasal swabs were cultured in 5% blood agar, and the isolates were phenotypically identified to genus level. A diverse respiratory microbial population was found, mostly composed of Gram-positive bacteria, including Staphylococcus spp., Bacillus spp., Streptococcus spp. and Corynebacterium spp. The microbiological profile from the nasal cavity of 911 horses was described, with the five most common profiles being: (1) Staphylococcus sp. + Gram-negative bacilli (12.67%), (2) Staphylococcus sp. in pure culture (12.47%), (3) Staphylococcus sp. + Bacillus sp. (10.10%), (4) Gram-negative bacilli in pure culture (6.93%), and (5) Staphylococcus sp. + Bacillus sp. + Gram-negative bacilli (6.73%). Streptococcus equi equi and Rhodococcus equi were detected in 34 horses (3.37%), demonstrating the presence of pathogenic bacteria along with commensal microorganisms in apparently healthy animals. The disclosed data may guide and facilitate microbiological diagnosis of URT infection in horses. The significant presence of Gram-negative bacilli was evidenced, as well as the occurrence of relevant pathogens, such as S. equi equi and R. equi, thus helping to improve diagnosis and antimicrobial therapy.