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A clinical field trial to evaluate the efficacy of vaccination in controlling Salmonella infection and the association of Salmonella-shedding and weight gain in pigs Texte intégral
2010
A clinical field trial was performed to determine the effectiveness of an autogenous Salmonella Typhimurium bacterin compared with a commercial live S. Choleraesuis vaccine in pigs. The association between Salmonella shedding and weight gain was also investigated. Nine cohorts of weaned pigs, (330 to 350 pigs per cohort), were randomly assigned to 1 of 3 treatment groups (injection with S. Typhimurium bacterin, vaccination via water with S. Choleraesuis vaccine, or a control group receiving no vaccine). In each cohort, the average daily gain was calculated for a selected pen throughout the production stage. Pen (pooled) fecal samples were collected bi-weekly and cultured. The odds of Salmonella shedding in both vaccinated groups was higher than in the control group (P < 0.05). The prevalence of Salmonella shedding declined overall as pigs aged (P = 0.04). However, the control pigs showed the smallest decrease in Salmonella shedding over the entire production stage, while prevalence of Salmonella shedding in the vaccinated groups decreased twice as much as the control group over the entire production stage. Salmonella Typhimurium var. Copenhagen DT104, S. Cerro, and S. Agona, which had been isolated on the study farm previously, were recovered from pigs in this study. Shedding of S. Typhimurium var. Copenhagen decreased over time in both vaccine treatment groups. On the other hand, S. Cerro shedding rate was lower in the control pigs compared with vaccinated pigs and S. Agona could be recovered only from the samples collected from S. Choleraesuis vaccinated pigs. The pigs from pens with a higher Salmonella recovery rate experienced slower growth compared with pigs from pens where Salmonella was not isolated. This latter finding indicates that there might be an economic incentive for producers to try to control endemic salmonellosis if effective programs could be developed.
Afficher plus [+] Moins [-]Characteristics of the molecular diversity of the outer membrane protein A gene of Haemophilus parasuis Texte intégral
2010
The molecular diversity of the gene encoding the outer membrane protein A (OmpA) of Haemophilus parasuis has been unclear. In this study, the structural characteristics, sequence types, and genetic diversity of ompA were investigated in 15 H. parasuis reference strains of different serovars and 20 field isolates. Three nucleotide lengths of the complete open reading frame (ORF) of ompA were found: 1098 base pairs (bp), 1104 bp, and 1110 bp. The OmpA contained 4 hypervariable domains, mainly encoding the 4 putative surface-exposed loops, which makes it a potential molecular marker for genotyping. Western blot analysis showed that the recombinant OmpAs of serovars 4 and 5 could cross-react with antiserum to all 15 serovars. Hence, although ompA of H. parasuis exhibited high variation among serovars, this variation did not seem to affect the strong antigenic characteristics of OmpA.
Afficher plus [+] Moins [-]Distribution of capsular serotypes and virulence markers of Streptococcus suis isolated from pigs with polyserositis in Korea Texte intégral
2010
Kim, Duyeol | Han, Kiwon | Oh, Yeonsu | Kim, Chung Hyun | Kang, Ikjae | Lee, Jeehoon | Gottschalk, Marcelo | Chae, Chanhee
The objective of this study was to determine the capsular serotypes and potential virulence factors of Streptococcus suis isolated from pigs with polyserositis. Among the 24 isolates evaluated, serotype 3 [7 (29%) of the isolates] and serotype 4 [5 (21%)] were the most common. The isolates were also studied for the presence of the genes mrp, epf, and sly, which encode muramidase-released protein (MRP), extracellular factor (EF), and suilysin (SLY), respectively. Of the 24 isolates, 8 carried mrp: 4 of serotype 3, 2 of serotype 2, and 2 of serotype 4. One mrp+ isolate (serotype 2) also carried the epf gene. All 24 isolates carried the sly gene. The serotype and genotype distribution greatly differed from that reported for isolates from pigs with other clinical manifestations of S. suis infection in other countries.
Afficher plus [+] Moins [-]Effects of medetomidine-midazolam-fentanyl IV bolus injections and its reversal by specific antagonists on cardiovascular function in rabbits Texte intégral
2010
Baumgärtner, Christine | Bollerhey, Melanie | Ebner, Johanna | Schuster, Tibor | Henke, Julia | Erhardt, Wolf
The objective of this study was to investigate the short-term cardiovascular effects of intravenous (IV) medetomidine-midazolam-fentanyl (MMF) injections in the rabbit using vascular ultrasonography and echocardiography.Anesthesia with MMF was induced intramuscularly (IM) in 8 female New Zealand White rabbits before 3 defined bolus injections of MMF were given IV. Before and for 10 min after each MMF injection the following vascular variables [at the left common carotid artery (ACC) after the first injection and at the abdominal aorta (AA) after the second injection]: vessel diameter (D), peak systolic, minimum diastolic, end-diastolic and average blood flow velocities (psBFV, mdBFV, edBFV, Vave), average volumetric flow (VFave), resistance index (RI) and pulsatility index (PI) and other clinical variables: mean arterial pressure (MAP), heart rate (HR), peripheral arterial oxygen saturation and end-tidal CO2 were recorded. Echocardiography was used after the third injection to investigate changes in cardiac parameters. Additionally, hemodynamic effects were observed at the ACC after complete subcutaneous antagonism of anesthesia by atipamezole-flumazenil-naloxone (AFN) until recovery of the animals. Medetomidine-midazolam-fentanyl IV caused a significant decrease of blood flow velocity in both investigated vessels which was associated with a significant decrease of HR and cardiac performance indicated by the decrease of FS and average volumetric blood flow. Mean arterial pressure significantly increased after each MMF injection; whereas, it significantly decreased after AFN injection. Therefore, MMF and AFN should be carefully used in rabbits and may not be suitable in patients with ventricular dysfunction.
Afficher plus [+] Moins [-]Increased risk of chronic wasting disease in Rocky Mountain elk associated with decreased magnesium and increased manganese in brain tissue Texte intégral
2010
White, Stephen N. | O’Rourke, Katherine I. | Gidlewski, Thomas | VerCauteren, Kurt C. | Mousel, Michelle R. | Phillips, Gregory E. | Spraker, Terry R.
Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy (TSE) of Rocky Mountain elk in North America. Recent studies suggest that tissue and blood mineral levels may be valuable in assessing TSE infection in sheep and cattle. The objectives of this study were to examine baseline levels of copper, manganese, magnesium, zinc, selenium, and molybdenum in the brains of Rocky Mountain elk with differing prion genotypes and to assess the association of mineral levels with CWD infection. Elk with leucine at prion position 132 had significantly lower magnesium levels than elk with 2 copies of methionine. Chronic wasting disease-positive elk had significantly lower magnesium than control elk. The incorporation of manganese levels in addition to magnesium significantly refined explanatory ability, even though manganese alone was not significantly associated with CWD. This study demonstrated that mineral analysis may provide an additional disease correlate for assessing CWD risk, particularly in conjunction with genotype.
Afficher plus [+] Moins [-]Anti-obesity effects of onion juice in high fat diet-induced obese rats
2010
Kang, W.Y., Jeju National University, Jeju, Republic of Korea | Kim, M.Y., Jeju National University, Jeju, Republic of Korea | Jin, J.Y., Jeju National University, Jeju, Republic of Korea | Yang, H.K., Jeju National University, Jeju, Republic of Korea | Hong, H.J., Jeju National University, Jeju, Republic of Korea | Kim, D.G., Jeju National University, Jeju, Republic of Korea | Han, C.H., Jeju National University, Jeju, Republic of Korea | Lee, Y.J., Jeju National University, Jeju, Republic of Korea
This study investigated the effects of onion juice on the serum lipid components and blood pressure in obese rats fed high fat diets. Thirty-nine of Sprague-Dawley rats were divided into six groups, and were treated for 8 weeks: (1) normal diet (ND); (2) high fat diet (HFD); (3) HFD for first 4 weeks and high fat diet with 40% onion juice for the last 4weeks (H-H+O); (4) HFD with 40% onion juice for 8 weeks (H+O); (5) HFD for first 4 weeks and ND for the last 4 weeks (H-N); (6) HFD for first 4 weeks and ND with 40% onion juice for the last 4 weeks (H-N+O). The rates of increasing body weight were reduced in H+O and H-H+O groups compared with HFD group. The levels of triglyceride, low density lipoprotein-cholesterol and total cholesterol in blood serum were significantly decreased in the H+O and H-H+O groups compared with the HFD group. Administration of onion reduced the size of adipocyte, steatosis, and serum hyperlipidemia in obese rats fed HFD. Moreover, the antihypertensive effects of onion were observed in obesity rat fed HFD. Overall results suggest that onion reduces the serum lipid components and improves hypertension in obese rat fed HFD.
Afficher plus [+] Moins [-]Comparison of linear and non-linear equation for the calibration of roxithromycin analysis using liquid chromatography/mass spectrometry
2010
Lim, J.H., Chungnam National University, Daejeon, Republic of Korea | Yun, H.I., Chungnam National University, Daejeon, Republic of Korea
Linear and non-linear regressions were used to derive the calibration function for the measurement of roxithromycin plasma concentration. Their results were compared with weighted least squares regression by usual weight factors. In this paper the performance of a non-linear calibration equation with the capacity to account empirically for the curvature, y = ax∨b + c (b not equal to 1) is compared with the commonly used linear equation, y = ax + b, as well as the quadratic equation, y = ax²+ bx + c. In the calibration curve (range of 0.01 to 10 ㎍/mL) of roxithromycin, both heteroscedasticity and nonlinearity were present therefore linear least squares regression methods could result in large errors in the determination of roxithromycin concentration. By the non-linear and weighted least squares regression, the accuracy of the analytical method was improved at the lower end of the calibration curve. This study suggests that the non-linear calibration equation should be considered when a curve is required to be fitted to low dose calibration data which exhibit slight curvature.
Afficher plus [+] Moins [-]Sensitivity analysis of serological tests for detection of disease in cattle
2010
Lee, S.J., National Veterinary Research and Quarantine Service, Anyang, Republic of Korea | Moon, O.K., National Veterinary Research and Quarantine Service, Anyang, Republic of Korea | Pak, S.I., Kangwon National University, Chuncheon, Republic of Korea
Animal disease surveillance system, defined as the continuous investigation of a given population to detect the occurrence of disease or infection for control purposes, has been key roles to assess the health status of an animal population and, more recently, in international trade of animal and animal products with regard to risk assessment. Especially, for a system aiming to determine whether or not a disease is present in a population sensitivity of the system should be maintained high enough not to miss an infected animal. Therefore, when planning the implementation of surveillance system a number of factors that affecting surveillance sensitivity should be taken into account. Of these parameters sample size is of important, and different approaches are used to calculate sample size, usually depending on the objective of surveillance systems. The purpose of this study was to evaluate the sensitivity of the current national serological surveillance programs for four selected bovine diseases assuming a specified sampling plan, to examine factors affecting the probability of detection, and to provide sample sizes required for achieving surveillance goal of detecting at least an infection in a given population. Our results showed that, for example, detecting low level of prevalence (0.2% for bovine tuberculosis) requires selection of all animals per typical Korean cattle farm (n = 17), and thus risk-based target surveillance for high risk groups can be an alternative strategy to increase sensitivity while not increasing overall sampling efforts. The minimum sample size required for detecting at least one positive animal was sharply increased as the disease prevalence is low. More importantly, high reliability of prevalence estimation was expected with increased sampling fraction even when zero-infected animal was identified. The effect of sample size is also discussed in terms of the maximum prevalence when zero-infected animals were identified and on the probability of failure to detect an infection. We suggest that for many serological surveillance systems, diagnostic performance of the testing method, sample size, prevalence, population size, and statistical confidence need to be considered to correctly interpret results of the system.
Afficher plus [+] Moins [-]Transjugular occlusion of patent ductus arteriosus using an Amplatz canine ductal occluder in a Cocker spaniel dog
2010
Choi, R., Kangwon National University, Chuncheon, Republic of Korea | Hyun, C.B., Kangwon National University, Chuncheon, Republic of Korea
A 5-year-old female Cocker spaniel dog (body weight 7.0 kg) was presented with primary complaints of exercise intolerance and loud precordial thrill which was noticed since she was a puppy. Physical examination revealed a grade Ⅴ/Ⅵ continuous murmur over the maximal point of the left basal area, bounding femoral pulse, but no differential cyanosis. Tall R waves were detected in electrocardiogram, suggesting left ventricular enlargement. Diagnostic imaging studies showed enlarged left ventricle, bulged descending aorta (dAo), markedly dilated right pulmonary artery, and continuous shunt flow between the dAo and main pulmonary artery. Based on these findings, the dog was diagnosed as left to right shunted patent ductus arteriosus (PDA). The patent ductus arteriosus was treated by lodging a PDA duct occluder via the transvenous approach. Clinical signs were markedly improved after the ductal occlusion, the shunt flow was mildly persistent. The case presented is the first case of PDA occluded by the PDA duct occluder via the transvenous approach in a small breed of dog. Although the residual shunt flow was mildly persisted, the dog was clinically normal without detectable murmurs.
Afficher plus [+] Moins [-]Mycobacterium avium subsp. avium infection in a lineolated parakeet (Bolborhynchus lineola)
2010
Lee, S.Y., Konkuk University, Seoul, Republic of Korea | Yoo, J.H., Konkuk University, Seoul, Republic of Korea | Yoon, J.W., Chung-Ang University College of Medicine, Seoul, Republic of Korea | Kim, D.Y., University of Missouri, Columbia, MO, USA | Cho, H.S., University of Missouri, Columbia, MO, USA | Park, C., University of California, Davis, CA, USA | Park, H.M., Konkuk University, Seoul, Republic of Korea
A 2-year-old lineolated parakeet (Bolborhynchus lineola) was presented with abdominal distention and respiratory distress for two months. The bird was poorly fleshed and the liver was enlarged on coelomic palpation. Plain and contrast radiographic examinations exhibited hepatomegaly and distended intestinal loop, which compromised the air sacs. Multifocal yperechogenecity was observed in the liver on ultrasonography. Postmortem gross examination revealed hepatomegaly with numerous pinpoint tan foci in the hepatic parenchyma and distended small intestine filled with adult ascarids. Microscopically, granulomatous hepatitis and enteritis infected by intrahistiocytic acid-fast bacilli were evident. Polymerase chain reaction indicated that the acid-fast bacilli were Mycobacterium avium subsp. avium.
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