Comparison of the cardiopulmonary effects of anesthesia maintained by continuous infusion of ketamine and propofol with anesthesia maintained by inhalation of sevoflurane in goats undergoing magnetic resonance imaging

OBJECTIVE: To compare the cardiopulmonary effects of anesthesia maintained by continuous infusion of ketamine and propofol with anesthesia maintained by inhalation of sevoflurane in goats undergoing magnetic resonance imaging. ANIMALS: 8 Saanen goats. PROCEDURES: Goats were anesthetized twice (1-month interval) following sedation with midazolam (0.4 mg/kg, IV). Anesthesia was induced via IV administration of ketamine (3 mg/kg) and propofol (1 mg/kg) and maintained with an IV infusion of ketamine (0.03 mg/kg/min) and propofol (0.3 mg/kg/min) and 100% inspired oxygen (K-P treatment) or induced via IV administration of propofol (4 mg/kg) and maintained via inhalation of sevoflurane in oxygen (end-expired concentration, 2.3%; 1X minimum alveolar concentration; SEVO treatment). Cardiopulmonary and blood gas variables were assessed at intervals after induction of anesthesia. RESULTS: Mean +/- SD end-expired sevoflurane was 2.24 +/- 0.2%; ketamine and propofol were infused at rates of 0.03 +/- 0.002 mg/kg/min and 0.29 +/- 0.02 mg/kg/min, respectively. Overall, administration of ketamine and propofol for total IV anesthesia was associated with a degree of immobility and effects on cardiopulmonary parameters that were comparable to those associated with anesthesia maintained by inhalation of sevoflurane. Compared with the K-P treatment group, mean and diastolic blood pressure values in the SEVO treatment group were significantly lower at most or all time points after induction of anesthesia. After both treatments, recovery from anesthesia was good or excellent. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that ketamine-propofol total IV anesthesia in goats breathing 100% oxygen is practical and safe for performance of magnetic resonance imaging procedures.     

A filter-assisted culture method for isolation of Treponema spp. from bovine digital dermatitis and their identification by MALDI-TOF MS

Digital dermatitis (DD) is a major infectious foot disease of cattle worldwide. Some DD stages are associated with lameness, and the disease has significant economic and animal welfare consequences. The pathogenesis of the disease is not yet fully understood, but Treponema spp. have been associated consistently with clinical cases. Isolation of these fastidious bacteria is difficult and cumbersome. We describe an improved method enabling the culturing of the 3 Treponema spp. (T. pedis, T. phagedenis, and T. medium) from bovine foot specimens derived from DD lesions, using a combination of membrane filtering and subsequent growth on selective agar media. The entire procedure from sampling to verification of individual Treponema spp. takes up to 24 d. In addition, we established a MALDI-TOF MS–based identification method to be applied for confirmation of the different Treponema spp. This scheme provides an unambiguous, simple, and straightforward identification procedure for DD-associated Treponema spp.     

Comparison of TGF-beta 1 concentrations in bronchoalveolar fluid of horses affected with heaves and of normal controls

Airway remodeling may play an important role in heaves pathophysiology. Transforming growth factor-beta 1 (TGF-beta1) is a potent profibrotic cytokine, which might contribute to airway wall thickening and fibrosis of bronchiolar and alveolar submucosa. An ELISA designed for the measurement of human TGF-beta1 was used to measured total TGF-beta1 released in bronchoalveolar lavage fluid (BALF) of normal horses and of those affected with heaves in remission. The specificity of the assay for TGF-beta1 of the horse was confirmed using recombinant equine TGF-beta1. The influence of hay exposure on TGF-beta1 release in the airways was also examined by stabling horses in a dusty environment. TGF-beta1 was found in the BALF of all horses. However, no significant difference between basal concentration of TGF-beta1 in BALF of control horses versus that of horses affected with heaves was found. Furthermore, no differences were identified in these populations 1 and 9 days after allergen challenge. In conclusion, these data indicate that TGF-beta1 is released in BALF fluid of horses in biologically active concentrations. Other studies are necessary for a better definition of the role of this cytokine within the lung, as our study does not establish a causal relationship between TGF-beta1 and the pathophysiology of heaves in the horse.     

Development of a romifidine constant rate infusion with or without butorphanol for standing sedation of horses

ObjectiveTo determine constant rate infusion (CRI) protocols for romifidine (R) and romifidine combined with butorphanol (RB) resulting in constant sedation and romifidine plasma concentrations.Study designBlinded randomized crossover study.AnimalsTen adult research horses.MethodsPart I: After determining normal height of head above ground (HHAG = 100%), loading doses of romifidine (80 μg kg^?1) with butorphanol (RB: 18 μg kg^?1) or saline (R) were given intravenously (IV). Immediately afterwards, a butorphanol (RB: 25 μg kg^?1 hour^?1) or saline (R) CRI was administered for 2 hours. The HHAG was used as marker of sedation depth. Sedation was maintained for 2 hours by additional romifidine (20 μg kg^?1) whenever HHAG > 50%. The dose rate of romifidine (μg kg^?1 hour^?1) required to maintain sedation was calculated for both treatments. Part II: After loading doses, the romifidine CRIs derived from part I were administered in parallel to butorphanol (RB) or saline (R). Sedation and ataxia were evaluated periodically. Romifidine plasma concentrations were measured by HPLC-MS-MS at 0, 5, 10, 15, 30, 45, 60, 90, 105, and 120 minutes. Data were analyzed using paired t-test, Fisher's exact test, Wilcoxon signed rank test, and two-way anova for repeated measures (p < 0.05).ResultsThere was no significant difference in romifidine requirements (R: 30; RB: 29 μg kg^?1 hour^?1). CRI protocols leading to constant sedation were developed. Time to first additional romifidine bolus was significantly longer in RB (mean ± SD, R: 38.5 ± 13.6; RB: 50.5 ± 11.7 minutes). Constant plasma concentrations of romifidine were achieved during the second hour of CRI. Ataxia was greater when butorphanol was added.ConclusionRomifidine bolus, followed by CRI, provided constant sedation assessed by HHAG. Butorphanol was ineffective in reducing romifidine requirements in unstimulated horses, but prolonged the sedation caused by the initial romifidine bolus.Clinical relevanceBoth protocols need to be tested under clinical conditions.     

Can the protozoan parasite Bonamia ostreae infect larvae of flat oysters Ostrea edulis?

Bonamia ostreae is an intracellular protistan parasite affecting flat oysters Ostrea edulis. It can be detected in juveniles but mortalities mainly affect oysters which are more than 2 years old. The parasite is usually observed inside haemocytes and sometimes free, notably in gill epithelia suggesting a parasite release through this organ. However, the infective form and ways of entry and release remain undetermined. Flat oysters incubate their larvae in their pallial cavity for 8-10 days before releasing them into the water column. Flat oysters in Bay of Quiberon in South Brittany (France) are known to be infected with B. ostreae since 1979 and is the most important area in France for O. edulis spat collection. Flat oysters incubating larvae were sampled in this area during summertime between 2007 and 2009. Both adults and larvae were preserved and assayed by PCR and in situ hybridisation (ISH). PCR tests revealed the presence of parasite DNA in some adults and larvae. Specific labelling could be detected by ISH in gills, digestive system, gonad and mantle in adults and in the epithelium surrounding the visceral cavity of some larvae. Our results demonstrate that larvae can be infected with B. ostreae. Larvae might thus contribute to the spread of the parasite during their planktonic life. In addition, their transfer for aquaculture purpose should be controlled especially when they are exported from infected zones.     

Seasonal and Diurnal Variation in Simple Sugar and Fructan Composition of Orchardgrass Pasture and Hay in the Piedmont Region of the United States

Seasonal and diurnal changes in water-soluble carbohydrates (WSC) and ethanol-soluble carbohydrates (ESC), as well as in chromatographic profiles of the sugars comprising these categories, were studied in orchardgrass pastures at one location in the Piedmont region of Virginia. Grass from four experimental plots was sampled weekly in the morning and afternoon over an 8-week period (early to late spring). Tissue was air-dried to simulate hay, or frozen to preserve the sugar profiles of fresh pasture. WSC and ESC were assayed colorimetrically. To profile sugars, boiled-water extracts were separated by high-performance liquid chromatography coupled to pulsed amperometric detection. Fructan, glucose, fructose, and sucrose were quantified by high-performance liquid chromatography. All sugar concentrations were highest in the early spring in both fresh and dried tissue. Fructan chain length was highest in early spring as well. Significant diurnal differences were observed for WSC and fructan, on some dates (P < .0001 and P = .024, respectively), and for ESC, glucose, and sucrose averaged over the entire period (P = .0002, .004, and <.0001, respectively). Sucrose was barely detectable in fresh tissue but reached 1.6% to 12% dry matter in dried tissue. These results demonstrate changes in orchardgrass carbohydrates over a season, within a day, and between dried and fresh herbage. Understanding these changes may be helpful in the management of horses with a history of insulin resistance and laminitis.     

Seasonal and Diurnal Changes in Starch Content and Sugar Profiles of Bermudagrass in the Piedmont Region of the United States

Seasonal and diurnal patterns of sugar accumulation in bermudagrass (Cynodon dactylon) pastures were monitored to evaluate risk factors for pasture-associated laminitis of ponies and horses. Bermudagrass was collected from four plots in the morning and afternoon on a weekly basis, from mid-July until late August. Tissue was air-dried to simulate hay, or frozen to retain the sugar profiles of fresh pasture. Samples were analyzed colorimetrically for total water-soluble and ethanol-soluble carbohydrates, and electrochemically for starch. In addition, sugars were separated and quantified by high-performance liquid chromatography coupled to pulsed amperometric detection. The dominant sugars in extracts were glucose, fructose, and sucrose. Some minor peaks, corresponding to tri- and tetrasaccharides, were also detected in some extracts. Starch increased over time in fresh and dried tissue, and concentrations varied diurnally in fresh, but not in dried tissue (P = .021). Sucrose in dried tissue decreased and then increased, with higher concentrations than in fresh tissue on all sampling dates (P = .024). Glucose and fructose exhibited diurnal variation on one and two dates, respectively (P = .034 and .0028, respectively). These results reveal trends in carbohydrate concentrations and profiles that may help to evaluate the likelihood of equine laminitis outbreaks on bermudagrass.     

In silico prediction of Gallibacterium anatis pan-immunogens

The Gram-negative bacterium Gallibacterium anatis is a major cause of salpingitis and peritonitis in commercial egg-layers, leading to reduced egg production and increased mortality. Unfortunately, widespread multidrug resistance and antigenic diversity makes it difficult to control infections and novel prevention strategies are urgently needed. In this study, a pan-genomic reverse vaccinology (RV) approach was used to identify potential vaccine candidates. Firstly, the genomes of 10 selected Gallibacterium strains were analyzed and proteins selected on the following criteria; predicted surface-exposure or secretion, none or one transmembrane helix (TMH), and presence in six or more of the 10 genomes. In total, 42 proteins were selected. The genes encoding 27 of these proteins were successfully cloned in Escherichia coli and the proteins expressed and purified. To reduce the number of vaccine candidates for in vivo testing, each of the purified recombinant proteins was screened by ELISA for their ability to elicit a significant serological response with serum from chickens that had been infected with G. anatis. Additionally, an in silico prediction of the protective potential was carried out based on a protein property prediction method. Of the 27 proteins, two novel putative immunogens were identified; Gab_1309 and Gab_2312. Moreover, three previously characterized virulence factors; GtxA, FlfA and Gab_2156, were identified. Thus, by combining the pan-genomic RV approach with subsequent in vitro and in silico screening, we have narrowed down the pan-proteome of G. anatis to five vaccine candidates. Importantly, preliminary immunization trials indicated an in vivo protective potential of GtxA-N, FlfA and Gab_1309.

Electronic supplementary material

The online version of this article (doi:10.1186/s13567-014-0080-0) contains supplementary material, which is available to authorized users.