| 1. |
- Ovesen, Louise, et al.
(författare)
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Antimicrobial Susceptibility of Bacteroides spp. From Clinical Samples From Horses
- 2016
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Ingår i: Journal of Equine Veterinary Science. - : Elsevier BV. - 0737-0806 .- 1542-7412. ; 45, s. 46-52
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Tidskriftsartikel (refereegranskat)abstract
- The objective of the study was to determine the antimicrobial susceptibility of 28 individual clinical isolates from horses, previously identified by phenotypic methods as Bacteroides spp., and to species identify these isolates using matrix-assisted-laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and 16S rRNA gene sequencing. Rarely are Bacteroides spp. identified to species level, and treatment of infection with anaerobes is seldom guided by antimicrobial susceptibility testing. The gram-negative anaerobic rods were species identified using MALDI-TOF MS and 16S rRNA gene sequencing. Antimicrobial susceptibility was determined by nitrocefin hydrolysis and broth microdilution. The isolates were identified as Bacteroides fragilis, Bacteroides heparinolyticus, Bacteroides ovatus, Bacteroides pyogenes, Bacteroides thetaiotaomicron, Bacteroides sp., Parabacteroides distasonis, Porphyromonas sp., Prevotella sp., and Prevotella dentasini. All isolates had low minimum inhibitory concentrations (MICs) of metronidazole. beta-Lactamase production and high MICs of penicillin, cephalothin, ceftiofur, erythromycin, fusidic acid, and trimethoprim/sulfamethoxazole were recorded for B. fragilis, B. ovatus, and B. thetaiotaomicron. Parabacteroides distasonis did not produce beta-lactamase but were still resistant to penicillin and in addition to the aforementioned substances also had high MICs of tetracycline. Bacteroides heparinolyticus, B. pyogenes, and the isolates identified as Porphyromonas sp., Prevotella sp., and P. dentasini did not produce beta-lactamase and were generally more susceptible against the tested antimicrobial agents. It is concluded that antimicrobial susceptibility differs substantially between species of genus Bacteroides and it is difficult to species identify anaerobic gram-negative rods by conventional phenotypic methods. It is important both to species identify gram-negative anaerobic rods and perform antimicrobial susceptibility testing to ensure correct treatment. (C) 2016 Elsevier Inc. All rights reserved.
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| 2. |
- Pringle, John, et al.
(författare)
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Long term silent carriers of Streptococcus equi ssp. equi following strangles; carrier detection related to sampling site of collection and culture versus qPCR
- 2019
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Ingår i: Veterinary Journal. - : Elsevier BV. - 1090-0233 .- 1532-2971. ; 246, s. 66-70
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Tidskriftsartikel (refereegranskat)abstract
- After strangles outbreaks, Streptococcus equi ssp. equi (S. equi) can persist in clinically normal silent carriers for months to years. Two naturally occurring outbreaks of strangles with 53 and 100% morbidity, respectively, were followed longitudinally to assess occurrence of carrier state and optimal detection methods Outbreak A involved 98 yearling warmbloods, and outbreak B 38 mature Icelandic horses. Fully recovered horses were sampled at least 6 months after index cases using nasal swabs (one sampling occasion only) nasopharyngeal lavage and guttural pouch visualisation and lavages for culture and qPCR to S. equi. Any horse with at least a single sample positive was deemed a carrier. Descriptive statistics and sensitivity and negative predictive values were calculated. Comparisons were made with McNemars and Fishers exact tests.Carrier rates in outbreak A were 3% based on culture and 15% based on qPCR and for outbreak B 13% based on culture and 37% based on qPCR. All culture positives were also qPCR positive. One carrier culture negative sampled after an additional 8 months was culture positive to S. equi, indicating that qPCR positives should be suspected to carry live bacteria. Findings indicate that reliance on guttural pouch sampling and appearance does not capture all silent carriers. All culture positives were identified by qPCR and even horses positive by qPCR but culture negative should be suspected carriers of live bacteria. (C) 2019 Elsevier Ltd. All rights reserved.
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| 3. |
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| 4. |
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| 5. |
- Riihimäki, Miia, et al.
(författare)
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Decreased Clinical Severity of Strangles in Weanlings Associated with Restricted Seroconversion to Optimized Streptococcus equi ssp equi Assays
- 2018
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Ingår i: Journal of Veterinary Internal Medicine. - : Wiley. - 0891-6640 .- 1939-1676. ; 32, s. 459-464
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Tidskriftsartikel (refereegranskat)abstract
- Background: Streptococcus equi ssp. equi causes characteristic clinical signs that are most severe in young horses, including fever, purulent nasal discharge, and lymph node abscessation in the head region.Hypothesis/Objectives: Clinical, serologic, and microbiologic factors related to unexpectedly mild disease severity in a natural outbreak of strangles in immunologically naive weanlings were investigated.Animals: One-hundred and twelve warmblood weanlings.Methods: Prospective longitudinal observational study of a natural outbreak of strangles. The entire cohort was examined at the peak of the outbreak by deep nasal swabs for culture and quantitative PCR (qPCR) for the presence of S. equi and clinically and serologically in a sequential manner by an optimized ELISA from the index case throughout the outbreak until resolution. Descriptive statistics were calculated and comparisons made using a nondirectional Wilcoxon signed-rank test.Results: Outbreak morbidity was 53%, with 9 of 14 horses culture positive and 26 of 53 horses qPCR positive for S. equi lacking clinical signs characteristic of strangles. By resolution, 91 of 112 had seroconverted to Antigen A by ELISA but seroconversion to antigen C (part of the SeM protein) was minimal. Sequencing of the isolates detected no alterations in the SeM protein, but identified a 61 bp deletion in the gene SEQ_0402.Conclusions and Clinical Importance: Absence of clinical signs alone in naive horses may be an insufficient criterion to release horses from strangles quarantine measures. Restricted seroconversion to antigen C may have been associated with decreased clinical severity. The role of a minor gene deletion in SEQ_0402 in the virulence of S. equi warrants further investigation.
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| 6. |
- Riihimäki, Miia, et al.
(författare)
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Long term dynamics of a Streptococcus equi ssp equi outbreak, assessed by qPCR and culture and seM sequencing in silent carriers of strangles
- 2018
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Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 223, s. 107-112
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to use culture, qPCR and seM sequencing to map Streptococcus equi subspec. equi (S.equi) isolates in long term carrier animals. A strangles outbreak affecting 41 Icelandic horses was followed to determine strangles free status using nasal and/or guttural pouch lavages collected serially on eleven separate occasions over 13 months. Ten persistent carriers, of which eight had repeated culture positive samples for S. equi, were selected for the study. Of 115 samples collected, 61 were S. equi positive on qPCR; from which 32 were also culture positive. Amplification of parts of the gene encoding the M-protein seM was performed on isolated colony material (n = 32) or, where only PCR product was obtained, directly on the DNA sample (n = 29) with a nested amplification approach. The seM sequence could be determined for six of the 29 samples that were solely qPCR positive. The outbreak was due to a S. equi strain of seM type 72. Three months after initial sampling isolates from two horses had seM gene sequences with one amino acid change. After six months S. equi with truncated seM genes were found in two horses; one variant in a single horse once, and in the other horse a variant that persisted and that was later identified in two additional horses. Non- mucoid S. equi colonies were found in two horses. Importantly, after acute strangles outbreaks many horses not only remain persistently qPCR positive for S. equi but are also intermittently culture positive.
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| 7. |
- Riihimäki, Miia, et al.
(författare)
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Seasonal Variation in Tracheal Mucous and Bronchoalveolar Lavage Cytology for Adult Clinically Healthy Stabled Horses
- 2018
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Ingår i: Journal of Equine Veterinary Science. - : Elsevier BV. - 0737-0806 .- 1542-7412. ; 71, s. 1-5
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Tidskriftsartikel (refereegranskat)abstract
- Seasonal changes affect the concentration of dust particles and aeroallergens in the equine stable environment and are hypothesized to change airway cytology in healthy stabled horses. The objective of the study was to evaluate if seasonal changes from May to November influenced the lower airway health cytological findings in clinically healthy stabled horses. Endoscopic examination, including tracheal aspiration (TA) and bronchoalveolar lavage (BAL) cytology was performed in November and May on 63 clinically healthy stabled Danish Warmblood geldings, aged 12.9 (+/- 4.6) years. Tracheal aspiration and BAL cytology were evaluated via May-Grfinwald-Giemsa stain after cytocentrifugation of samples. Five-hundred cells were identified microscopically as macrophages, lymphocytes, neutrophils, eosinophils, or mast cells. A significant difference in climatic conditions with lower temperatures (P < .001), fewer sunlight hours (P = .004), less precipitation (P = .006), and higher humidity (P < .001) was found in November compared to May. A significantly higher percentage of neutrophils (Median 6.10%, Quartiles 4.00-8.80, P < .001) and a higher tracheal mucus score (Median 3.50%, Quartiles 1.95-5.20, P = .010) were found during November compared to May period. Furthermore, a positive correlation between TA and BAL neutrophils was found for both sampling times. Mild winter weather conditions with lower temperatures, fewer minutes of sunlight, and a higher percent humidity were associated with significantly higher BAL neutrophil percentage and significantly higher mucus score in stabled clinical healthy horses. The clear seasonal influence on BAL neutrophilia and tracheal mucous findings in clinically normal horse needs to be included in the working diagnosis of asthma in horses. (C) 2018 Elsevier Inc. All rights reserved.
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| 8. |
- Riihimäki, Miia, et al.
(författare)
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Viral load of equine herpesviruses 2 and 5 in nasal swabs of actively racing Standardbred trotters: Temporal relationship of shedding to clinical findings and poor performance
- 2015
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Ingår i: Veterinary Microbiology. - : Elsevier BV. - 0378-1135 .- 1873-2542. ; 179, s. 142-148
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Tidskriftsartikel (refereegranskat)abstract
- The equine gamma herpesviruses 2 and 5 (EHV-2 and -5) have frequently been observed in the equine population and until recently presumed low to nonpathogenic. However, recent reports linking presence of equine gamma herpesviruses with clinical signs of mild to severe lung disease, suggest that the role of these viruses in respiratory disease and poor performance syndrome is still unclear. Moreover, baseline data regarding the temporal pattern of shedding of EHV-2 and EHV-5 within stables and within individual actively racing horses have been lacking. In a prospective longitudinal study, we followed elite racing Standardbred trotters at monthly intervals for 13 months, to investigate whether the amount of EHV-2 and EHV-5 shedded in nasal secretions varied over time within and between individual horses. Sixty-six elite horses were investigated by analyzing nasal swabs and serum samples, a health check and evaluation of athletic performance monthly during the study period. Nasal swabs were analyzed with two newly developed qPCR assays for EHV-2 and EHV-5, respectively. Of 663 samples, 197 (30%) were positive for EHV-2 and 492(74%) positive for EHV-5. Furthermore, 176(27%) of the samples were positive for both EHV-2 and EHV-5 simultaneously. There was considerable variation in the amount and frequency of shedding of EHV-2 and EHV-5 within and between individual horses. Viral load varied seasonally, but neither EHV-2 nor EHV-5 viral peaks were associated with clinical respiratory disease and/or poor performance in racing Standardbred trotters. (C) 2015 Elsevier B.V. All rights reserved.
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| 9. |
- Wernersson, Sara, et al.
(författare)
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Equine Airway Mast Cells are Sensitive to Cell Death Induced by Lysosomotropic Agents
- 2017
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Ingår i: Scandinavian Journal of Immunology. - : Wiley. - 0300-9475 .- 1365-3083. ; 85, s. 30-34
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Tidskriftsartikel (refereegranskat)abstract
- Mast cells are known for their detrimental effects in various inflammatory conditions. Regimens that induce selective mast cell apoptosis may therefore be of therapeutic significance. Earlier studies have demonstrated that murine-and human-cultured mast cells are highly sensitive to apoptosis induced by the lysosomotropic agent LeuLeuOMe (LLME). However, the efficacy of lysosomotropic agents for inducing apoptosis of in vivo-derived airway mast cells and the impact on mast cells in other species have not been assessed. Here we addressed whether lysosomotropic agents can induce cell death of equine in vivo-derived mast cells. Bronchoalveolar lavage (BAL) fluids from horses were incubated with LLME at 15-100 lM for up to 48 h. The overall cell viability was unaffected by 15 lM LLME up to 48 h, whereas a relatively modest drop in total cell counts (similar to 30%) was seen at the highest LLME dose used. In contrast to the relatively low effect on total cell counts, LLME efficiently and dose dependently reduced the number of mast cells in BAL fluids, with an almost complete depletion (96%) of mast cells after 24 h of incubation with 100 lM LLME. A significant but less dramatic reduction (up to similar to 45%) of lymphocytes was also seen, whereas macrophages and neutrophils were essentially resistant. The appearance of apoptotic bodies suggested a mechanism involving apoptosis rather than necrosis. These findings suggest that equine airway mast cells are highly sensitive to lysosomotropic agents. Possibly, lysosomotropic agents could be of therapeutic value to treat disorders involving harmful accumulation of mast cells in the airways.
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