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The aim of this study was to assess the probability of detecting Salmonella from pen faecal samples in seropositive classified finishing pig herds. The study involved 77 herds from Denmark (20), The Netherlands (20), Greece (17) and Germany (20). The serological herd status was determined by the blood-sampling of 50 finishing pigs. Bacteriological sampling was performed by 20 pen faecal samples per herd. Over-all, 47% of the blood samples had an OD% larger than 10 and 23% larger than 40. Salmonella was isolated from 135 (9.3%) pen faecal samples in 32 herds (42%). Twenty-eight of these herds (87.5%) had a within-herd seroprevalence larger than 50% at sample cut-off OD% > 10. In our study, there was an increasing probability of recovering Salmonella with increasing within-herd seroprevalence. However, this was only a moderate correlation. A correlation coefficient of 0.62 was found between the proportion of culture positive- and seropositive samples in a herd at cut-off OD%> 10 and of 0.58 at cut-off OD% > 40. Serology is a measure of historical exposure, which may or may not correlate closely to the microbiological burden at the time of sampling. Due to the low sensitivity of culture methods, apparent 'false-positive' serological results may well represent real infections not detected by bacteriological testing. For screening purposes, serological testing provides an indication of exposure to Salmonella, which forms the basis for targeted sampling, intervention and logistic slaughter procedures.  相似文献   
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There is considerable interest in the spatial distribution of Echinococcus multilocularis in red foxes (Vulpes vulpes L.), because this parasite causes the zoonoses of alveolar echinococcosis which is potentially of high fatality rate. High risk areas are known from France, Switzerland and the Swabian Alb in Germany for a long time. In this work, the spatial scan statistic is introduced as an instrument for identification and localisation of high risk areas, so called disease clusters in spatial epidemiology. The use of the spatial scan statistic along with data about the distribution of the parasite in 5365 red foxes in Lower Saxony, that were collected during 1991 to 1997, led to the identification of another high risk area. The relative risk for this disease cluster is approximated by RR = 5.03 (CI0.95(RR) = [4.27; 6.58]) for the period of 1991 to 1994 and by RR = 4.45 (CI0.95(RR) = [3.53; 5.59]) for the period of 1994 to 1997, respectively.  相似文献   
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Bovine articular cartilage was photo-oxidized and cultured with native articular bovine cartilage and synovial membrane to study the interaction between these tissues mimicking the physiological situation in the joint. The photo-oxidation was applied as a pretreatment of cartilage for future use in cartilage resurfacing procedures in joints. Properties of the transplant were assessed by testing the production of local mediators, such as nitric oxide (NO) and prostaglandin E2 (PGE2), and neutral metalloproteinase activities under normal conditions and after stimulation with various stimulants representative of inflammatory changes in pathophysiological conditions. Unlike normal cartilage photo-oxidized cartilage did not release significant amounts of NO and PGE2 and showed less gelatinolytic and caseinolytic activity compared to native bovine articular cartilage. Enzyme activity of the combined cultures was at a level intermediate between that of photo-oxidized cartilage and native cartilage cultures alone. In contrast to normal cartilage, living chondrocytes were not visible in photo-oxidized cartilage using live/dead staining. These results indicate, that the photo-oxidized cartilage may have a beneficial effect on adjacent native host cartilage and therefore be a suitable transplant for use in in vivo experiments.  相似文献   
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ABSTRACT A leaf spot disease with unknown etiology has become more pronounced in spring and winter barley in Germany in recent years. The symptoms are similar to net blotch and Ramularia leaf spots, but the causal agents of these diseases are not identified. The symptom expression varied much on cultivars. Cultivars most affected by the disease of both spring and winter barley showed a significantly higher level of superoxide (O(2) ) production and lipid peroxidation (malondialdehyde), but a lower level of antioxidant potential expressed as superoxide dismutase (SOD) activity, catalase activity, and integral water-soluble antioxidant capacity (ACW) than insensitive cultivars. A high positive correlation between O(2) production and leaf spot development between ear emergence and milk ripeness was established in the most sensitive winter barley cv. Anoa (r(2) = 0.9622) and spring barley cv. Barke (r(2) = 0.9434). Leaf H(2)O(2) levels increased with the severity of leaf spots. The histochemical localization of O(2) and H(2)O(2) in the tissues adjacent to leaf spots indicated that these two active oxygen species (AOS) are involved in the formation of leaf spots. Reduction of symptom severity by applying strobilurin and azole fungicides was always associated with elevated SOD activity and ACW content and suppressed O(2) production. However, peroxidase activities were significantly higher in sensitive cultivars and in more severely affected tissues and decreased by applying fungicides. Thus, it is assumed that a possible genetic mechanism based on the imbalanced AOS metabolism contributes to formation of physiological leaf spots.  相似文献   
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Reports of human salmonellosis caused by the consumption of pork and the introduction of control and surveillance programmes in different countries of the European Union were the reason for carrying out an international study under the title "Salmonella in Pork (Salinpork)": Six different EU-countries were involved in this study, which was supported by the Commission of the European Community and which was carried out over a period of April 1996 to April 1999. The aim of the investigation presented was to determine the prevalence of Salmonella in fattening, breeding and farrow-to-feeder herds as well as the determination of risk factors for the introduction of Salmonella into the farm (Part 1). In addition, sources of contamination of pork should be detected by taking samples of the product and the environment in the slaughterhouse (Part 2). In Germany, the investigation into Salmonella infections of 60 fattening, 20 breeding and 20 farrow-to-feeder herds were carried out in Schleswig-Holstein. The investigation included bacteriological examinations of feed and faecal samples for sero- and phagetyping and serological examinations by using the Danish Mix-ELISA. From 2,947 serological investigated fattening pigs were 7.3% (n = 213) positive, from 797 breeding sows 9.2% (n = 73) were serological positive and 4.5% (n = 18) of the investigated sows (N = 399) in farrow-to-feeder herds were serological positive. Altogether, 28.3% of the fattening, 50.0% of the breeding and 15.0% of the farrow-to-feeder herds were serological positive. A questionnaire was used to capture data about management, hygiene measures, feeding systems and the occurrence of diseases in the herd. After statistical analysis the common risk factor of fattening herds and sow herds was the use of pelleted feed. But in a control study with 17 different fattening herds the result could not be proven. Other factors which can influence the occurrence of Salmonella infections were discussed.  相似文献   
29.
In 1997 bacteriological examinations for the distribution of Salmonella in slaughterhouses were carried out in Germany within the framework of an international study "Salmonella in Pork (Salinpork)". During 6 days, 1,200 swab and water samples from slaughtered pigs and the environment were taken. 4.4% of the samples (n = 53) were Salmonella positive. S. typhimurium was isolated mainly (69.8%; n = 37), and 6 phagetypes were differentiated. In addition, S. derby and S. panama could be demonstrated. The resistance pattern of the different isolated S. typhimurium-phagetypes are presented. The phagetype DT 104 was multiresistant to ampicillin, spectinomycin, streptomycin, sulphonamide and tetracycline. In comparison with the serological prevalence of 7.3% of the fattening pigs in the farms (Part 1), only 1.0% of the samples taken from the surface of the carcass were Salmonella-positive. Swabs taken from the liver were in 2.7% positive and samples from the tongue gave in 5.3% of the cases Salmonella-positive results. In the examination of the environment Salmonella was demonstrated mainly from the water outlets, whereas Salmonella could not be isolated from water of the scalding tank. There was only one case (0.7%) in which Salmonella could be isolated from the hands of the personnel, and also only one swab of the polishing machine was positive (1.1%). But 6.7% samples of the saw were Salmonella-positive. A comparison of repeated, at intervals taken samples showed that the number of Salmonella-positive samples was higher in the last examination round of the particular slaughter days. The reason is suspected in the increasing number of slaughtered pigs and supplying farms, which may increase the probability of bringing in Salmonella.  相似文献   
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The increase in the knowledge of the genetic variability of BVDV and the identification of some of the genetic determinants of its pathogenicity require robust and practical tools for rapid molecular characterization of the various genotypes of this virus. This study was undertaken to develop a standard protocol for RT-PCR that allows the amplification of various parts of the genome of BVDV without the need for optimizing each individual reaction. The reaction set-up is very flexible because it consists of two pre-mixes. These are a master mix, with all the required reagents except the desired primers, which are the components of the second pre-mix and are therefore easily interchangeable between the different reactions. After adding any primer-containing pre-mix to the fixed master mix, a non-interrupted cycling protocol led to the generation of amplicons of up to 4 kbp in size in amounts sufficient for subsequent sequencing reactions. The method was applied to five different regions of the BVDV genome: (i) the well-known 5-UTR to differentiate genotypes I and II; (ii) the entire E2 gene, or an approximately 550 bp region within the E2 gene, in order to find the molecular equivalent of antigenic varieties; (iii) the entire structural protein coding region covering the Npro, capsid, E RNS, E1 and E2 genes; (iv) a 2.1 kbp region embracing the NS2/3 junction which is known to be cleaved in cytopathic biotypes of BVDV; and (v) the region covering the entire NS4B and NS5A/B genes. All six RT-PCRs were successfully applied using (i) primers with lengths of between 20 and 52 nucleotides, (ii) an aliquot of RNA extracted from either 106 infected bovine embryonal lung cells or the same number of leukocytes from viraemic cattle, and (iii) all the genotype I and II strains of BVDV tested. The technique described was used to generate various Sindbis virus/BVDV recombinants. The correct processing of the amplicon-derived E2 glycoprotein of BVDV strain PT810 was demonstrated by its reaction with a monoclonal antibody in an immunofluorescence assay. Given the variety of RT-PCRs tested, we conclude that this universal protocol may be useful with other RNA viruses.  相似文献   
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