Characteristics of Salmonella isolated from an outbreak of equine salmonellosis in a veterinary teaching hospital

During an outbreak of equine salmonellosis in a veterinary teaching hospital 20 Salmonella isolates were cultured from sick horses (13 isolates) or from the hospital environment (7 isolates). Three serotypes were isolated from the environment including: S. give, S. newportand S. agona. The serotypes isolated from horses included: S. give, S. newport and S. anatum. Examination of antibiotic profiles, presence of plasmids, production of bacteriocins and hemagglutination of erythrocytes implied a common origin for the equine and environmental isolates.     

Melatonin reduces apoptotic cells,SOD2 and HSPB1 and improves the in vitro production and quality of bovine blastocysts

Effects of adding different concentrations of melatonin (10^?7, 10^?9 and 10^?11 M) to maturation (Experiment 1; Control, IVM  + 10^?7, IVM  + 10^?9, IVM  + 10^?11) and culture media (Experiment 2; Control, IVC  + 10^?7, IVC  + 10^?9, IVC  + 10^?11) were evaluated on in vitro bovine embryonic development. The optimal concentration of melatonin (10^?9 M) from Experiments 1–2 was tested in both maturation and/or culture media of Experiment 3 (Control, IVM  + 10^?9, IVC  + 10^?9, IVM /IVC  + 10^?9). In Experiment 1, maturated oocytes from Control and IVM  + 10^?9 treatments showed increased glutathione content, mitochondrial membrane potential and percentage of Grade I blastocysts (40.6% and 43%, respectively). In Experiment 2, an increase in the percentage of Grade I blastocysts was detected in IVC  + 10^?7 (43.5%; 56.7%) and IVC  + 10^?9 (47.4%; 57.4%). Moreover, a lower number and percentage of apoptotic cells in blastocysts were observed in the IVC  + 10^?9 group compared to Control (3.8 ± 0.6; 3.6% versus 6.1 ± 0.6; 5.3%). In Experiment 3, the IVC  + 10^?9 treatment increased percentage of Grade I blastocysts with a lower number of apoptotic cells compared to IVM /IVC  + 10^?9 group (52.6%; 3.0 ± 0.5 versus 46.0%; 5.4 ± 1.0). The IVC  + 10^?9 treatment also had a higher mRNA expression of antioxidant gene (SOD 2) compared to the Control, as well as the heat shock protein (HSPB 1) compared to the IVM  + 10^?9. Reactive oxygen species production was greater in the IVM /IVC  + 10^?9 treatment group. In conclusion, the 10^?9 M concentration of melatonin and the in vitro production phase in which it is used directly affected embryonic development and quality.     

Hyoscine‐N‐butylbromide premedication on cardiovascular variables of horses sedated with medetomidine

ObjectiveTo evaluate the effects of intravenous (IV) or intramuscular (IM) hyoscine premedication on physiologic variables following IV administration of medetomidine in horses.Study designRandomized, crossover experimental study.AnimalsEight healthy crossbred horses weighing 330 ± 39 kg and aged 7 ± 4 years.MethodsBaseline measurements of heart rate (HR), cardiac index (CI), respiratory rate, systemic vascular resistance (SVR), percentage of patients with second degree atrioventricular (2^oAV) block, mean arterial pressure (MAP), pH, and arterial partial pressures of carbon dioxide (PaCO₂) and oxygen (PaO₂) were obtained 5 minutes before administration of IV hyoscine (0.14 mg kg^?1; group HIV), IM hyoscine (0.3 mg kg^?1; group HIM), or an equal volume of physiologic saline IV (group C). Five minutes later, medetomidine (7.5 μg kg^?1) was administered IV and measurements were recorded at various time points for 130 minutes.ResultsMedetomidine induced bradycardia, 2^oAV blocks and increased SVR immediately after administration, without significant changes in CI or MAP in C. Hyoscine administration induced tachycardia and hypertension, and decreased the percentage of 2^oAV blocks induced by medetomidine. Peak HR and MAP were higher in HIV than HIM at 88 ± 18 beats minute^?1 and 241 ± 37 mmHg versus 65 ± 16 beats minute^?1 and 192 ± 38 mmHg, respectively. CI was increased significantly in HIV (p ≤ 0.05). Respiratory rate decreased significantly in all groups during the recording period. pH, PaCO₂ and PaO₂ were not significantly changed by administration of medetomidine with or without hyoscine.Conclusion and clinical relevanceHyoscine administered IV or IM before medetomidine in horses resulted in tachycardia and hypertension under the conditions of this study. The significance of these changes, and responses to other dose rates, requires further investigation.     

Effect of feeding selected carbohydrates on the in vivo attachment of Salmonella typhimurium in chick ceca.

Two-day-old chicks were orally inoculated with 1 ml of Salmonella typhimurium (10(5) colony-forming units/ml) and divided into four groups. Three groups were fed 2.5% carbohydrates starting on day 1 (arabinose, galactose, and lactose), while the fourth group served as the control. Ceca were obtained from each group at 7, 14, and 21 days. At the end of 14 days, all three carbohydrates statistically reduced Salmonella recovery. However, lactose failed to reduce recovery between day 14 and day 21. Arabinose and galactose continued to show significant reductions of recovery through 21 days. No statistical difference was found between Salmonella recovery from whole ceca (with cecal material) and inverted ceca (washed free of cecal material).     

Use of sodium monoiodoacetate to fuse the distal hock joints in horses

SUMMARY Intra-articular injection of sodium monoiodoacetate (MIA) was investigated as an agent for chemical arthrodesis of the distal hock joints in the horse. Five horses diagnosed with either spavin (three horses), a small tarsal bone fracture or a failed surgical arthrodesis, had 150 mg of MIA injected into the tarsometatarsal (TMT) joint of the affected hock(s). Eight joints were treated in the five horses. Follow-up evaluation by clinical and radiological examination took place over 9 to 14 months. Two of the five horses were sound at the conclusion of the study and one horse, although lame after flexion, was considered by the owner to have been treated successfully. One of eight TMT joints showed complete radiographic fusion. Complications after treatment included pain, chronic lameness and swelling. It was concluded that chemical arthrodesis using this technique can not be recommended as being a superior treatment as compared with surgical arthrodesis at this time but is deserving of further clinical evaluation.     

Antibacterial action of combinations of oxytetracycline, dimethyl sulfoxide, and EDTA-tromethamine on Proteus, Salmonella, and Aeromonas

Antibacterial effects against Proteus mirabilis, Salmonella typhimurium, and Aeromonas hydrophila were obtained with subminimal inhibitory concentrations of oxytetracycline and EDTA-tromethamine. Antibacterial effects were not observed with subminimal inhibitory concentrations of dimethyl sulfoxide plus oxytetracycline or with dimethyl sulfoxide plus EDTA-tromethamine. Using a 2-dimensional Microtiter checkerboard technique, inhibitory activities of the various combinations of solutions were studied, and isobolograms were plotted. A synergistic effect was seen with combinations of oxytetracycline and EDTA-tromethamine. The greatest synergistic effect was observed when the mixture was caused to react with P mirabilis. These findings were confirmed by kinetic studies of microbial death, using one-fourth minimal inhibitory concentrations of these preparations.     

Effect of feeding selected short-chain fatty acids on the in vivo attachment of Salmonella typhimurium in chick ceca.

Two groups of 20 chicks each were fed 1% fatty acid continuously starting at 1 day of age, while a control group of 20 chicks received unsupplemented feed. At 2 days of age, chicks were inoculated orally with 1 ml of Salmonella typhimurium (1 x 10(6) colony-forming units/ml). Ceca were obtained from six chicks of each group at 7, 14, and 21 days of age. At 14 days of age, formic and propionic acids had statistically reduced Salmonella recovery by 2.56 logs and 3.09 logs, respectively, compared with controls. At 21 days of age, both test groups showed significant reductions of approximately 3.6 logs compared with controls. There were no statistical differences in body weights among the groups at 21 days of age.