ABSTRACTSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causal agent of COVID-1... more ABSTRACTSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causal agent of COVID-19, can infect animals by binding to the angiotensin-converting enzyme 2 (ACE2). Equine infection appears possible due to high homology (≈97%) between human and equine ACE2, evidence ofin vitroinfection in cell lines expressing equine ACE2, and evidence of seroconversion in horses after exposure to persons infected with SARS-CoV-2. Our objective was to examine susceptibility of cultured primary equine bronchial epithelial cells (EBECs) to a SARS-CoV-2 pseudovirus relative to human bronchial epithelial cells (HBECs; positive control). ACE2 expression in EBECs detected by immunofluorescence, western immunoblotting, and flow cytometry was lower in EBECs than in HBECs. EBECs were transduced with a lentivirus pseudotyped with the SARS-CoV-2 spike protein that binds to ACE2 and expresses the enhanced green fluorescent protein (eGFP) as a reporter. Cells were co-cultivated with the pseudovirus a...
SummaryBackgroundStreptococcus equi subspecies equi (S equi) is the cause of Strangles, one of th... more SummaryBackgroundStreptococcus equi subspecies equi (S equi) is the cause of Strangles, one of the most prevalent diseases of horses worldwide. Variation within the immunodominant SeM protein has been documented, but a new eight‐component fusion protein vaccine, Strangvac, does not contain live S equi or SeM and conservation of the antigens it contains have not been reported.ObjectiveTo define the diversity of the eight Strangvac antigens across a diverse S equi population.Study designGenomic description.MethodsAntigen sequences from the genomes of 759 S equi isolates from 19 countries, recovered between 1955 and 2018, were analysed. Predicted amino acid sequences in the antigen fragments of SEQ0256(Eq5), SEQ0402(Eq8), SEQ0721(EAG), SEQ0855(SclF), SEQ0935(CNE), SEQ0999(IdeE), SEQ1817(SclI) and SEQ2101(SclC) in Strangvac and SeM were extracted from the 759 assembled genomes and compared.ResultsThe predicted amino acid sequences of SclC, SclI and IdeE were identical across all 759 gen...
Pneumonia caused by the intracellular bacterium Rhodococcus equi is an important cause of disease... more Pneumonia caused by the intracellular bacterium Rhodococcus equi is an important cause of disease and death in immunocompromised hosts, especially foals. Antibiotics are the standard of care for treating R. equi pneumonia in foals, and adjunctive therapies are needed. We tested whether nebulization with TLR agonists (PUL-042) in foals would improve innate immunity and reduce the severity and duration of pneumonia following R. equi infection. Neonatal foals (n = 48) were nebulized with either PUL-042 or vehicle, and their lung cells infected ex vivo. PUL-042 increased inflammatory cytokines in BAL fluid and alveolar macrophages after ex vivo infection with R. equi. Then, the in vivo effects of PUL-042 on clinical signs of pneumonia were examined in 22 additional foals after intrabronchial challenge with R. equi. Foals infected and nebulized with PUL-042 or vehicle alone had a shorter duration of clinical signs of pneumonia and smaller pulmonary lesions when compared to non-nebulized ...
Evaluating the health and function of the gastrointestinal tract can be challenging in all specie... more Evaluating the health and function of the gastrointestinal tract can be challenging in all species, but is especially difficult in horses due to their size and length of the gastrointestinal (GI) tract. Isolation of mRNA of cells exfoliated from the GI mucosa into feces (i.e., the exfoliome) offers a novel means of non-invasively examining the gene expression profile of the GI mucosa. This approach has been utilized in people with colorectal cancer. Moreover, we have utilized this approach in a murine model of GI inflammation and demonstrated that the exfoliome reflects the tissue transcriptome. The ability of the equine exfoliome to provide non-invasive information regarding the health and function of the GI tract is not known. The objective of this study was to characterize the gene expression profile found in exfoliated intestinal epithelial cells from normal horses and compare the exfoliome data with the tissue mucosal transcriptome. Mucosal samples were collected from standardized locations along the GI tract (i.e. ileum, cecum, right dorsal colon, and rectum) from four healthy horses immediately following euthanasia. Voided feces were also collected. RNA isolation, library preparation, and RNA sequencing was performed on fecal and intestinal mucosal samples. Comparison of gene expression profiles from the tissue and exfoliome revealed correlation of gene expression. Moreover, the exfoliome contained reads representing the diverse array of cell types found in the GI mucosa suggesting the equine exfoliome serves as a noninvasive means of examining the global gene expression pattern of the equine GI tract.
M proteins are surface-anchored virulence factors in group A streptococci, human pathogens. Here,... more M proteins are surface-anchored virulence factors in group A streptococci, human pathogens. Here, we identified an M-like protein, SzM, and its positive regulator, SezV, in Streptococcus equi subspecies zooepidemicus (SEZ), an important group of pathogens for domesticated animals, including horses and pigs. SzM and SezV homologues were found in the genomes of all SEZ and S. equi subspecies equi and M18 group A streptococcal strains analyzed but not in other streptococci. Mutant SEZ strains lacking either sezV or szM were highly attenuated in a mouse model of infection. Collectively, our findings suggest that SezV-related regulators and the linked SzM family of M-like proteins define a new subset of virulent streptococci.
Current recommendations for identification of Salmonella enteritidis (SE) contaminated eggs, as o... more Current recommendations for identification of Salmonella enteritidis (SE) contaminated eggs, as outlined by the USDA SE Task Force, require the combination of yolk and albumen from several eggs for room-temperature enrichment for 3 days prior to culture on solid medium. We describe the use of enzymatic digestion and chemical reduction to reduce viscosity and allow for concentration of Salmonella cells in egg albumen by centrifugation prior to enrichment and plating. In these studies, sanitized, intact, fresh shell eggs were inoculated with low numbers of viable SE. Albumen and yolk from six eggs in each group were separated; the albumen was pooled, treated with the proteolytic enzyme papain and the reducing agent N-acetyl-l-cysteine, and centrifuged, and the resulting pellet was incubated in tetrathionate broth (5 ml) at 37°C for 24 h prior to plating on brilliant green agar (BOA). For comparison, yolk and albumen from six eggs in each group were pooled, thoroughly mixed, and incuba...
Reasons for performing study: The prognosis for horses with longitudinal tears of the deep digita... more Reasons for performing study: The prognosis for horses with longitudinal tears of the deep digital flexor tendon (DDFT) is poor for both medical and surgical treatments. Barbed sutures are used in human medicine to close tendon lesions, but there is little evidence of their use in equines.
The incidence of macrolide and rifampin resistance in R. equi isolated from foals has increased c... more The incidence of macrolide and rifampin resistance in R. equi isolated from foals has increased considerably in recent years. The objective of this study was to identify the molecular mechanism of emerging macrolide resistance in R. equi and to determine its transferability. Macrolide-resistant (n¼62) and macrolide susceptible (n¼62) clinical isolates of R. equi from foals in the USA were studied. Whole genome sequencing of a sample of 18 macrolide-resistant and 6 macrolide-susceptible R. equi was performed. PCR was used to screen for the presence of the resistance determinant in the other isolates. Mating experiments were performed to document transfer of the determinant. A novel erm gene, erm(46) was identified only in resistant isolates. There was perfect association between macrolide resistance and Contents lists available at ScienceDirect
Journal of veterinary internal medicine / American College of Veterinary Internal Medicine, 2016
Adverse effects of, and bacterial resistance to, macrolides used to treat Rhodococcus equi infect... more Adverse effects of, and bacterial resistance to, macrolides used to treat Rhodococcus equi infections have prompted search for clinically effective alternative antimicrobials. Liposomal gentamicin (LG) is effective against R. equi in vitro and decreases tissue concentrations of R. equi in experimentally infected mice. Effectiveness of LG treatment of foals with R. equi pneumonia, however, has not been described. Liposomal gentamicin is safe and effective for treating foals with R. equi pneumonia. Ten foals with experimentally induced R. equi pneumonia. Pilot treatment trial. Foals with pneumonia induced by intrabronchial instillation of R. equi were randomly allocated to receive either clarithromycin combined with rifampin (CLR + RIF) PO or LG IV, and followed by daily physical examinations and weekly thoracic ultrasonography and serum creatinine concentration determinations until the resolution of clinical signs. Treatment success was defined as the resolution of clinical signs and...
Journal of Veterinary Diagnostic Investigation, 1995
Salmonella was identified in feces from horses, using the polymerase chain reaction (PCR) and gen... more Salmonella was identified in feces from horses, using the polymerase chain reaction (PCR) and genus-specific oligonucleotide primers. Feces from healthy horses were determined to be culture negative and PCR negative for Salmonella. Fecal samples were inoculated with known numbers of colony-forming units (CFU) of S. enteritidis. The fecal samples were enriched overnight in tetrathionate broth, and then DNA was extracted and amplified by PCR using genus-specific primers. Sensitivity of the assay extended to 100 CFU Salmonella enteritidis/g feces; sensitivity of microbiologic culture with enrichment extended to 100 CFU Salmonella enteritidis/g feces. Feces that were not inoculated with S. enteritidis were negative by the PCR. Detection of salmonellae in feces was possible using the PCR within 24 hours from the time of submission of samples. Because samples were enriched, isolates were available for determining antibiograms and serologic grouping or typing.
Antimicrobial agents and chemotherapy, Jan 29, 2018
To determine the prevalence of strains resistant to macrolides and rifampicin over time in clinic... more To determine the prevalence of strains resistant to macrolides and rifampicin over time in clinical samples from foals submitted to diagnostic laboratories in central Kentucky. Retrospective observational study of all clinical samples from foals that were submitted to veterinary diagnostics laboratories in Kentucky between January 1995 and December 2017. Samples were included if was cultured and tested for susceptibility to erythromycin or rifampicin. susceptibility to erythromycin was available for 2169 isolates of while susceptibility to both erythromycin and rifampicin was available for 1681 isolates. Rifampicin resistance was first detected in 2000 and erythromycin resistance was first detected in 2004. Between 1995 and 2006, the proportion of resistant isolates of was 0.7% for erythromycin and 2.3% for rifampicin. There was a significant (P <0.001) increase in the proportion of resistant between 2007 and 2017, with 13.6% of isolates being resistant to erythromycin and 16.1% ...
Podotrochlear syndrome is a common cause of lameness in Quarter Horses involving both soft tissue... more Podotrochlear syndrome is a common cause of lameness in Quarter Horses involving both soft tissue and bony structures within the heel region. Current surgical treatment of podotrochlear syndrome addresses pathological changes affecting the soft tissue structures of the navicular region but does not address either edema or cyst-like lesions of the navicular bone. Objective: The objective of this randomized, self-controlled case series was to determine whether core osteostixis improved lameness in Quarter Horses with podotrochlear syndrome characterized by bilateral magnetic resonance imaging (MRI) findings of osseous cystlike lesions of the navicular bone. Methods: Seven Quarter Horses that had not responded to standard medical management were included. Each horse had an affected forefoot randomly assigned to surgical treatment with navicular bursoscopy and core osteostixis; the contralateral limb was assigned to navicular bursoscopy only. Video recordings were used to assign lameness scores and make comparisons of each limb at baseline and 24 weeks post-operatively by an observer blinded to the surgical treatment. A second MRI was performed 24 weeks after surgery to reevaluate navicular bone edema, osseous cyst-like lesions of the navicular bone, and tears of the deep digital flexor tendon (DDFT). Results: Reduction of lameness score from baseline was significantly (P = 0.0254) greater for the limbs treated with core osteostixis than limbs treated with bursoscopy. New DDFT tears were noted in 3 of 7 limbs treated with core osteostixis and in 1 of 7 bursoscopy limbs. Conclusion: Results of this study suggest that core osteostixis of the navicular bone combined with navicular bursoscopy can improve lameness in horses with osseous cyst-like lesions. Further evaluation of this technique is warranted.
Rhodococcus equiis a major cause of foal pneumonia and an opportunistic pathogen in immunocomprom... more Rhodococcus equiis a major cause of foal pneumonia and an opportunistic pathogen in immunocompromised humans. While alveolar macrophages constitute the primary replicative niche forR.equi, little is known about how intracellularR. equiis sensed by macrophages. Here, we discovered that in addition to previously characterized pro-inflammatory cytokines (e.g.,Tnfa,Il6,Il1b), macrophages infected withR.equiinduce a robust type I IFN response, includingIfnband interferon-stimulated genes (ISGs), similar to the evolutionarily related pathogen,Mycobacterium tuberculosis. Follow up studies using a combination of mammalian and bacterial genetics demonstrated that induction of this type I IFN expression program is largely dependent on the cGAS/STING/TBK1 axis of the cytosolic DNA sensing pathway, suggesting thatR.equiperturbs the phagosomal membrane and causes DNA release into the cytosol following phagocytosis. Consistent with this, we found that a population of ~12% ofR.equiphagosomes recru...
and the fifth sentence of the first paragraph of the Discussion are incorrect. The vapN carriage ... more and the fifth sentence of the first paragraph of the Discussion are incorrect. The vapN carriage of R. equi isolated from human infections from Brazil was reported during the revision process of this article [2] and an isolate from Japan has been previously identified [3]. The two sentences in question were not corrected between revisions.
SummaryA 4‐month‐old Thoroughbred filly presented with pyrexia, inappetence and diarrhoea. Abdomi... more SummaryA 4‐month‐old Thoroughbred filly presented with pyrexia, inappetence and diarrhoea. Abdominal ultrasonography revealed a multilobulated abdominal mass that was determined to be associated with the caecum using computed tomography. Computed tomography also identified mesenteric lymphadenopathy and a pulmonary mass in the left caudal lung lobe. Percutaneous aspiration of the abdominal mass yielded pure growth of Rhodococcus equi. The filly responded in a positive fashion to the administration of clarithromycin, rifampin and gallium maltolate. Follow‐up computed tomography revealed complete resolution of the abdominal mass and lymphadenopathy. Extrapulmonary disorders associated with R. equi should be considered even when thoracic ultrasonography reveals no evidence of pulmonary pathology. Although intra‐abdominal abscesses have a grave prognosis, successful treatment is possible. Gallium maltolate can be safely administered to foals and may improve patient outcomes.
Distal limb wounds are common injuries sustained by horses and their healing is fraught with comp... more Distal limb wounds are common injuries sustained by horses and their healing is fraught with complications due to equine anatomy, prevalence of infection, and challenges associated with wound management. Gallium is a semi-metallic element that has been shown to possess antimicrobial properties and aid in wound healing in various preclinical models. The effects of Gallium have not been studied in equine wound healing. Therefore, the objective of this study was to compare healing rates between gallium-treated and untreated wounds of equine distal limbs and to demonstrate the antimicrobial effects of gallium on wounds inoculated with S. aureus. Using an established model of equine wound healing we demonstrated beneficial effects of 0.5% topical gallium maltolate on equine wound healing. Specifically we documented reduced healing times, reduced bioburden, and reduced formation of exuberant granulation tissue in wounds treated with gallium maltolate as compared with untreated wounds. Gallium appeared to exert its beneficial effects via its well-described antimicrobial actions as well as by altering the expression of specific genes known to be involved in wound healing of horses and other animals. Specifically, gallium maltolate appeared to increase expression of transforming growth factor-β in both infected and uninfected wounds. Further work is needed to document the effects of gallium on naturally occurring equine wounds and to compare the effects of gallium with other wound treatment options. These data, however, suggest that gallium may be an attractive and novel means of improving equine distal limb wound healing.
Small intestinal damage induced by nonsteroidal anti-inflammatory drugs (NSAIDs) remains an under... more Small intestinal damage induced by nonsteroidal anti-inflammatory drugs (NSAIDs) remains an under-recognized clinical disorder. The incomplete understanding of the pathophysiology has hampered the development of prevention and treatment strategies leading to the high morbidity and mortality rates. NSAIDs are known to modulate macroautophagy, a process indispensable for intestinal homeostasis. Whether NSAIDs stimulate or repress macroautophagy and how this correlates with the clinical manifestations of NSAID enteropathy, however, remains unknown. The objectives of this study were to determine whether NSAIDs impaired macroautophagy and how this affects macroautophagy-regulated intestinal epithelial cell (IEC) processes essential for intestinal homeostasis (i.e., clearance of invading pathogens, secretion and composition of mucus building blocks, and inflammatory response). We show that NSAID treatment of IECs inhibits macroautophagy in vitro and in vivo. This inhibition was likely att...
A 2-year-old Thoroughbred racehorse had LF lameness that began post high-speed exercise and persi... more A 2-year-old Thoroughbred racehorse had LF lameness that began post high-speed exercise and persisted for two days before the horse once again became sound. Diagnostic analgesia localized the lameness to the LF distal metacarpus, and a standing MRI identified a unicortical condylar fracture. A single 5.5 mm cortical screw was placed in lag fashion. The horse began hand walking at 14 days, racetrack jogging at 30 days, and racing at 5 months after the day of surgery. Placement of a single lag screw ahead of the tip of the crack in unicortical condylar fracture may be useful for reducing the recovery period for horses returning to training and racing.
Foreword and Acknowledgements Sedation and mechanical hypoalgesia induced by four different dosag... more Foreword and Acknowledgements Sedation and mechanical hypoalgesia induced by four different dosages of butorphanol in xylazinepremedicated donkeys I. LIZARRAGA AND F. CASTILLO-ALCALA Different methods to identify pain after routine surgical castration of equine stallions: composite pain scale, facial expressions, faecal glucocorticoid metabolites and plasma cytokines Clinical Research Abstracts British Equine Veterinary Association Congress 2014 Foreword and Acknowledgements This supplement contains a diverse selection of abstracts addressing clinical research from many disciplines. Topics that are particularly well represented this year include endocrinology, laminitis, critical care and spinal disease. The only consistent feature is the very high standard. This year, BEVA has devoted an extra two sessions to abstracts, but despite this increased time, the selection process was difficult due to the large number of excellent submissions. Over the last years or so, Clinical Research Abstracts have progressively risen in stature and it is now the go-to place for cutting-edge, clinically relevant information delivered in a concise and highly professional manner. This is where Congress attendees will find the snippets of information to take straight back to practice to effect changes in the way of case management. By publishing this supplement in EVJ, BEVA hopes to make this new and relevant research available to those who have not been able to attend the Congress in person. Perhaps, this supplement will inspire some readers to make the trip next year. This year's BEVA Congress Clinical Research Abstracts have involved a more detailed review process than in the past. Brief reports on the abstracts under consideration were obtained from two peer reviewers before being graded, and ultimately selected by a subset of the Congress Scientific Programme
OBJECTIVE To evaluate the effect of volume of IV regional limb perfusion (IVRLP) on amikacin conc... more OBJECTIVE To evaluate the effect of volume of IV regional limb perfusion (IVRLP) on amikacin concentrations in synovial and interstitial fluid of horses. ANIMALS 8 healthy adult horses. PROCEDURES Each forelimb was randomly assigned to receive IVRLP with 4 mL of amikacin sulfate solution (250 mg/mL) plus 56 mL (total volume, 60 mL) or 6 mL (total volume, 10 mL) of lactated Ringer solution. Horses were anesthetized, and baseline synovial and interstitial fluid samples were collected. A tourniquet was placed, and the assigned treatment was administered via the lateral palmar digital vein. Venous blood pressure in the distal portion of the limb was recorded. Additional synovial fluid samples were collected 30 minutes (just before tourniquet removal) and 24 hours after IVRLP began; additional interstitial fluid samples were collected 6 and 24 hours after IVRLP began. RESULTS 30 minutes after IVRLP began, mean amikacin concentration in synovial fluid was significantly greater for the lar...
ABSTRACTSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causal agent of COVID-1... more ABSTRACTSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causal agent of COVID-19, can infect animals by binding to the angiotensin-converting enzyme 2 (ACE2). Equine infection appears possible due to high homology (≈97%) between human and equine ACE2, evidence ofin vitroinfection in cell lines expressing equine ACE2, and evidence of seroconversion in horses after exposure to persons infected with SARS-CoV-2. Our objective was to examine susceptibility of cultured primary equine bronchial epithelial cells (EBECs) to a SARS-CoV-2 pseudovirus relative to human bronchial epithelial cells (HBECs; positive control). ACE2 expression in EBECs detected by immunofluorescence, western immunoblotting, and flow cytometry was lower in EBECs than in HBECs. EBECs were transduced with a lentivirus pseudotyped with the SARS-CoV-2 spike protein that binds to ACE2 and expresses the enhanced green fluorescent protein (eGFP) as a reporter. Cells were co-cultivated with the pseudovirus a...
SummaryBackgroundStreptococcus equi subspecies equi (S equi) is the cause of Strangles, one of th... more SummaryBackgroundStreptococcus equi subspecies equi (S equi) is the cause of Strangles, one of the most prevalent diseases of horses worldwide. Variation within the immunodominant SeM protein has been documented, but a new eight‐component fusion protein vaccine, Strangvac, does not contain live S equi or SeM and conservation of the antigens it contains have not been reported.ObjectiveTo define the diversity of the eight Strangvac antigens across a diverse S equi population.Study designGenomic description.MethodsAntigen sequences from the genomes of 759 S equi isolates from 19 countries, recovered between 1955 and 2018, were analysed. Predicted amino acid sequences in the antigen fragments of SEQ0256(Eq5), SEQ0402(Eq8), SEQ0721(EAG), SEQ0855(SclF), SEQ0935(CNE), SEQ0999(IdeE), SEQ1817(SclI) and SEQ2101(SclC) in Strangvac and SeM were extracted from the 759 assembled genomes and compared.ResultsThe predicted amino acid sequences of SclC, SclI and IdeE were identical across all 759 gen...
Pneumonia caused by the intracellular bacterium Rhodococcus equi is an important cause of disease... more Pneumonia caused by the intracellular bacterium Rhodococcus equi is an important cause of disease and death in immunocompromised hosts, especially foals. Antibiotics are the standard of care for treating R. equi pneumonia in foals, and adjunctive therapies are needed. We tested whether nebulization with TLR agonists (PUL-042) in foals would improve innate immunity and reduce the severity and duration of pneumonia following R. equi infection. Neonatal foals (n = 48) were nebulized with either PUL-042 or vehicle, and their lung cells infected ex vivo. PUL-042 increased inflammatory cytokines in BAL fluid and alveolar macrophages after ex vivo infection with R. equi. Then, the in vivo effects of PUL-042 on clinical signs of pneumonia were examined in 22 additional foals after intrabronchial challenge with R. equi. Foals infected and nebulized with PUL-042 or vehicle alone had a shorter duration of clinical signs of pneumonia and smaller pulmonary lesions when compared to non-nebulized ...
Evaluating the health and function of the gastrointestinal tract can be challenging in all specie... more Evaluating the health and function of the gastrointestinal tract can be challenging in all species, but is especially difficult in horses due to their size and length of the gastrointestinal (GI) tract. Isolation of mRNA of cells exfoliated from the GI mucosa into feces (i.e., the exfoliome) offers a novel means of non-invasively examining the gene expression profile of the GI mucosa. This approach has been utilized in people with colorectal cancer. Moreover, we have utilized this approach in a murine model of GI inflammation and demonstrated that the exfoliome reflects the tissue transcriptome. The ability of the equine exfoliome to provide non-invasive information regarding the health and function of the GI tract is not known. The objective of this study was to characterize the gene expression profile found in exfoliated intestinal epithelial cells from normal horses and compare the exfoliome data with the tissue mucosal transcriptome. Mucosal samples were collected from standardized locations along the GI tract (i.e. ileum, cecum, right dorsal colon, and rectum) from four healthy horses immediately following euthanasia. Voided feces were also collected. RNA isolation, library preparation, and RNA sequencing was performed on fecal and intestinal mucosal samples. Comparison of gene expression profiles from the tissue and exfoliome revealed correlation of gene expression. Moreover, the exfoliome contained reads representing the diverse array of cell types found in the GI mucosa suggesting the equine exfoliome serves as a noninvasive means of examining the global gene expression pattern of the equine GI tract.
M proteins are surface-anchored virulence factors in group A streptococci, human pathogens. Here,... more M proteins are surface-anchored virulence factors in group A streptococci, human pathogens. Here, we identified an M-like protein, SzM, and its positive regulator, SezV, in Streptococcus equi subspecies zooepidemicus (SEZ), an important group of pathogens for domesticated animals, including horses and pigs. SzM and SezV homologues were found in the genomes of all SEZ and S. equi subspecies equi and M18 group A streptococcal strains analyzed but not in other streptococci. Mutant SEZ strains lacking either sezV or szM were highly attenuated in a mouse model of infection. Collectively, our findings suggest that SezV-related regulators and the linked SzM family of M-like proteins define a new subset of virulent streptococci.
Current recommendations for identification of Salmonella enteritidis (SE) contaminated eggs, as o... more Current recommendations for identification of Salmonella enteritidis (SE) contaminated eggs, as outlined by the USDA SE Task Force, require the combination of yolk and albumen from several eggs for room-temperature enrichment for 3 days prior to culture on solid medium. We describe the use of enzymatic digestion and chemical reduction to reduce viscosity and allow for concentration of Salmonella cells in egg albumen by centrifugation prior to enrichment and plating. In these studies, sanitized, intact, fresh shell eggs were inoculated with low numbers of viable SE. Albumen and yolk from six eggs in each group were separated; the albumen was pooled, treated with the proteolytic enzyme papain and the reducing agent N-acetyl-l-cysteine, and centrifuged, and the resulting pellet was incubated in tetrathionate broth (5 ml) at 37°C for 24 h prior to plating on brilliant green agar (BOA). For comparison, yolk and albumen from six eggs in each group were pooled, thoroughly mixed, and incuba...
Reasons for performing study: The prognosis for horses with longitudinal tears of the deep digita... more Reasons for performing study: The prognosis for horses with longitudinal tears of the deep digital flexor tendon (DDFT) is poor for both medical and surgical treatments. Barbed sutures are used in human medicine to close tendon lesions, but there is little evidence of their use in equines.
The incidence of macrolide and rifampin resistance in R. equi isolated from foals has increased c... more The incidence of macrolide and rifampin resistance in R. equi isolated from foals has increased considerably in recent years. The objective of this study was to identify the molecular mechanism of emerging macrolide resistance in R. equi and to determine its transferability. Macrolide-resistant (n¼62) and macrolide susceptible (n¼62) clinical isolates of R. equi from foals in the USA were studied. Whole genome sequencing of a sample of 18 macrolide-resistant and 6 macrolide-susceptible R. equi was performed. PCR was used to screen for the presence of the resistance determinant in the other isolates. Mating experiments were performed to document transfer of the determinant. A novel erm gene, erm(46) was identified only in resistant isolates. There was perfect association between macrolide resistance and Contents lists available at ScienceDirect
Journal of veterinary internal medicine / American College of Veterinary Internal Medicine, 2016
Adverse effects of, and bacterial resistance to, macrolides used to treat Rhodococcus equi infect... more Adverse effects of, and bacterial resistance to, macrolides used to treat Rhodococcus equi infections have prompted search for clinically effective alternative antimicrobials. Liposomal gentamicin (LG) is effective against R. equi in vitro and decreases tissue concentrations of R. equi in experimentally infected mice. Effectiveness of LG treatment of foals with R. equi pneumonia, however, has not been described. Liposomal gentamicin is safe and effective for treating foals with R. equi pneumonia. Ten foals with experimentally induced R. equi pneumonia. Pilot treatment trial. Foals with pneumonia induced by intrabronchial instillation of R. equi were randomly allocated to receive either clarithromycin combined with rifampin (CLR + RIF) PO or LG IV, and followed by daily physical examinations and weekly thoracic ultrasonography and serum creatinine concentration determinations until the resolution of clinical signs. Treatment success was defined as the resolution of clinical signs and...
Journal of Veterinary Diagnostic Investigation, 1995
Salmonella was identified in feces from horses, using the polymerase chain reaction (PCR) and gen... more Salmonella was identified in feces from horses, using the polymerase chain reaction (PCR) and genus-specific oligonucleotide primers. Feces from healthy horses were determined to be culture negative and PCR negative for Salmonella. Fecal samples were inoculated with known numbers of colony-forming units (CFU) of S. enteritidis. The fecal samples were enriched overnight in tetrathionate broth, and then DNA was extracted and amplified by PCR using genus-specific primers. Sensitivity of the assay extended to 100 CFU Salmonella enteritidis/g feces; sensitivity of microbiologic culture with enrichment extended to 100 CFU Salmonella enteritidis/g feces. Feces that were not inoculated with S. enteritidis were negative by the PCR. Detection of salmonellae in feces was possible using the PCR within 24 hours from the time of submission of samples. Because samples were enriched, isolates were available for determining antibiograms and serologic grouping or typing.
Antimicrobial agents and chemotherapy, Jan 29, 2018
To determine the prevalence of strains resistant to macrolides and rifampicin over time in clinic... more To determine the prevalence of strains resistant to macrolides and rifampicin over time in clinical samples from foals submitted to diagnostic laboratories in central Kentucky. Retrospective observational study of all clinical samples from foals that were submitted to veterinary diagnostics laboratories in Kentucky between January 1995 and December 2017. Samples were included if was cultured and tested for susceptibility to erythromycin or rifampicin. susceptibility to erythromycin was available for 2169 isolates of while susceptibility to both erythromycin and rifampicin was available for 1681 isolates. Rifampicin resistance was first detected in 2000 and erythromycin resistance was first detected in 2004. Between 1995 and 2006, the proportion of resistant isolates of was 0.7% for erythromycin and 2.3% for rifampicin. There was a significant (P <0.001) increase in the proportion of resistant between 2007 and 2017, with 13.6% of isolates being resistant to erythromycin and 16.1% ...
Podotrochlear syndrome is a common cause of lameness in Quarter Horses involving both soft tissue... more Podotrochlear syndrome is a common cause of lameness in Quarter Horses involving both soft tissue and bony structures within the heel region. Current surgical treatment of podotrochlear syndrome addresses pathological changes affecting the soft tissue structures of the navicular region but does not address either edema or cyst-like lesions of the navicular bone. Objective: The objective of this randomized, self-controlled case series was to determine whether core osteostixis improved lameness in Quarter Horses with podotrochlear syndrome characterized by bilateral magnetic resonance imaging (MRI) findings of osseous cystlike lesions of the navicular bone. Methods: Seven Quarter Horses that had not responded to standard medical management were included. Each horse had an affected forefoot randomly assigned to surgical treatment with navicular bursoscopy and core osteostixis; the contralateral limb was assigned to navicular bursoscopy only. Video recordings were used to assign lameness scores and make comparisons of each limb at baseline and 24 weeks post-operatively by an observer blinded to the surgical treatment. A second MRI was performed 24 weeks after surgery to reevaluate navicular bone edema, osseous cyst-like lesions of the navicular bone, and tears of the deep digital flexor tendon (DDFT). Results: Reduction of lameness score from baseline was significantly (P = 0.0254) greater for the limbs treated with core osteostixis than limbs treated with bursoscopy. New DDFT tears were noted in 3 of 7 limbs treated with core osteostixis and in 1 of 7 bursoscopy limbs. Conclusion: Results of this study suggest that core osteostixis of the navicular bone combined with navicular bursoscopy can improve lameness in horses with osseous cyst-like lesions. Further evaluation of this technique is warranted.
Rhodococcus equiis a major cause of foal pneumonia and an opportunistic pathogen in immunocomprom... more Rhodococcus equiis a major cause of foal pneumonia and an opportunistic pathogen in immunocompromised humans. While alveolar macrophages constitute the primary replicative niche forR.equi, little is known about how intracellularR. equiis sensed by macrophages. Here, we discovered that in addition to previously characterized pro-inflammatory cytokines (e.g.,Tnfa,Il6,Il1b), macrophages infected withR.equiinduce a robust type I IFN response, includingIfnband interferon-stimulated genes (ISGs), similar to the evolutionarily related pathogen,Mycobacterium tuberculosis. Follow up studies using a combination of mammalian and bacterial genetics demonstrated that induction of this type I IFN expression program is largely dependent on the cGAS/STING/TBK1 axis of the cytosolic DNA sensing pathway, suggesting thatR.equiperturbs the phagosomal membrane and causes DNA release into the cytosol following phagocytosis. Consistent with this, we found that a population of ~12% ofR.equiphagosomes recru...
and the fifth sentence of the first paragraph of the Discussion are incorrect. The vapN carriage ... more and the fifth sentence of the first paragraph of the Discussion are incorrect. The vapN carriage of R. equi isolated from human infections from Brazil was reported during the revision process of this article [2] and an isolate from Japan has been previously identified [3]. The two sentences in question were not corrected between revisions.
SummaryA 4‐month‐old Thoroughbred filly presented with pyrexia, inappetence and diarrhoea. Abdomi... more SummaryA 4‐month‐old Thoroughbred filly presented with pyrexia, inappetence and diarrhoea. Abdominal ultrasonography revealed a multilobulated abdominal mass that was determined to be associated with the caecum using computed tomography. Computed tomography also identified mesenteric lymphadenopathy and a pulmonary mass in the left caudal lung lobe. Percutaneous aspiration of the abdominal mass yielded pure growth of Rhodococcus equi. The filly responded in a positive fashion to the administration of clarithromycin, rifampin and gallium maltolate. Follow‐up computed tomography revealed complete resolution of the abdominal mass and lymphadenopathy. Extrapulmonary disorders associated with R. equi should be considered even when thoracic ultrasonography reveals no evidence of pulmonary pathology. Although intra‐abdominal abscesses have a grave prognosis, successful treatment is possible. Gallium maltolate can be safely administered to foals and may improve patient outcomes.
Distal limb wounds are common injuries sustained by horses and their healing is fraught with comp... more Distal limb wounds are common injuries sustained by horses and their healing is fraught with complications due to equine anatomy, prevalence of infection, and challenges associated with wound management. Gallium is a semi-metallic element that has been shown to possess antimicrobial properties and aid in wound healing in various preclinical models. The effects of Gallium have not been studied in equine wound healing. Therefore, the objective of this study was to compare healing rates between gallium-treated and untreated wounds of equine distal limbs and to demonstrate the antimicrobial effects of gallium on wounds inoculated with S. aureus. Using an established model of equine wound healing we demonstrated beneficial effects of 0.5% topical gallium maltolate on equine wound healing. Specifically we documented reduced healing times, reduced bioburden, and reduced formation of exuberant granulation tissue in wounds treated with gallium maltolate as compared with untreated wounds. Gallium appeared to exert its beneficial effects via its well-described antimicrobial actions as well as by altering the expression of specific genes known to be involved in wound healing of horses and other animals. Specifically, gallium maltolate appeared to increase expression of transforming growth factor-β in both infected and uninfected wounds. Further work is needed to document the effects of gallium on naturally occurring equine wounds and to compare the effects of gallium with other wound treatment options. These data, however, suggest that gallium may be an attractive and novel means of improving equine distal limb wound healing.
Small intestinal damage induced by nonsteroidal anti-inflammatory drugs (NSAIDs) remains an under... more Small intestinal damage induced by nonsteroidal anti-inflammatory drugs (NSAIDs) remains an under-recognized clinical disorder. The incomplete understanding of the pathophysiology has hampered the development of prevention and treatment strategies leading to the high morbidity and mortality rates. NSAIDs are known to modulate macroautophagy, a process indispensable for intestinal homeostasis. Whether NSAIDs stimulate or repress macroautophagy and how this correlates with the clinical manifestations of NSAID enteropathy, however, remains unknown. The objectives of this study were to determine whether NSAIDs impaired macroautophagy and how this affects macroautophagy-regulated intestinal epithelial cell (IEC) processes essential for intestinal homeostasis (i.e., clearance of invading pathogens, secretion and composition of mucus building blocks, and inflammatory response). We show that NSAID treatment of IECs inhibits macroautophagy in vitro and in vivo. This inhibition was likely att...
A 2-year-old Thoroughbred racehorse had LF lameness that began post high-speed exercise and persi... more A 2-year-old Thoroughbred racehorse had LF lameness that began post high-speed exercise and persisted for two days before the horse once again became sound. Diagnostic analgesia localized the lameness to the LF distal metacarpus, and a standing MRI identified a unicortical condylar fracture. A single 5.5 mm cortical screw was placed in lag fashion. The horse began hand walking at 14 days, racetrack jogging at 30 days, and racing at 5 months after the day of surgery. Placement of a single lag screw ahead of the tip of the crack in unicortical condylar fracture may be useful for reducing the recovery period for horses returning to training and racing.
Foreword and Acknowledgements Sedation and mechanical hypoalgesia induced by four different dosag... more Foreword and Acknowledgements Sedation and mechanical hypoalgesia induced by four different dosages of butorphanol in xylazinepremedicated donkeys I. LIZARRAGA AND F. CASTILLO-ALCALA Different methods to identify pain after routine surgical castration of equine stallions: composite pain scale, facial expressions, faecal glucocorticoid metabolites and plasma cytokines Clinical Research Abstracts British Equine Veterinary Association Congress 2014 Foreword and Acknowledgements This supplement contains a diverse selection of abstracts addressing clinical research from many disciplines. Topics that are particularly well represented this year include endocrinology, laminitis, critical care and spinal disease. The only consistent feature is the very high standard. This year, BEVA has devoted an extra two sessions to abstracts, but despite this increased time, the selection process was difficult due to the large number of excellent submissions. Over the last years or so, Clinical Research Abstracts have progressively risen in stature and it is now the go-to place for cutting-edge, clinically relevant information delivered in a concise and highly professional manner. This is where Congress attendees will find the snippets of information to take straight back to practice to effect changes in the way of case management. By publishing this supplement in EVJ, BEVA hopes to make this new and relevant research available to those who have not been able to attend the Congress in person. Perhaps, this supplement will inspire some readers to make the trip next year. This year's BEVA Congress Clinical Research Abstracts have involved a more detailed review process than in the past. Brief reports on the abstracts under consideration were obtained from two peer reviewers before being graded, and ultimately selected by a subset of the Congress Scientific Programme
OBJECTIVE To evaluate the effect of volume of IV regional limb perfusion (IVRLP) on amikacin conc... more OBJECTIVE To evaluate the effect of volume of IV regional limb perfusion (IVRLP) on amikacin concentrations in synovial and interstitial fluid of horses. ANIMALS 8 healthy adult horses. PROCEDURES Each forelimb was randomly assigned to receive IVRLP with 4 mL of amikacin sulfate solution (250 mg/mL) plus 56 mL (total volume, 60 mL) or 6 mL (total volume, 10 mL) of lactated Ringer solution. Horses were anesthetized, and baseline synovial and interstitial fluid samples were collected. A tourniquet was placed, and the assigned treatment was administered via the lateral palmar digital vein. Venous blood pressure in the distal portion of the limb was recorded. Additional synovial fluid samples were collected 30 minutes (just before tourniquet removal) and 24 hours after IVRLP began; additional interstitial fluid samples were collected 6 and 24 hours after IVRLP began. RESULTS 30 minutes after IVRLP began, mean amikacin concentration in synovial fluid was significantly greater for the lar...
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