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71.
Résumé Les antisérums sont obtenus en immunisant deux lapins par voie intraveineuse avec des antigènes purifiés par chromatographie
d'échange d'ions. On utilise deux préparations d'extraits mycéliens: normale et chauffée. La spécificité des anticorps obtenus
est appréciée sur différentes souches deRhizoctonia. Deux techniques sérologiques sont utilisées: immunodiffusion et ELISA indirect. Les deux immunsérums obtenus présentent
la même spécificité vis-à-vis du groupe AG3. Les deux techniques permettent la reconnaissance du groupe AG3 à partir des sclérotes
formés sur tubercules.
Summary Total mycelial extract ofR. solani AG3 was purified by ion-exchange chromatography. Beforehand part of the extract was heat-treated at 60°C for 10 min (Ch) and the rest left untreated (N). Results of the chromatographic analysis are given in Fig. 3. Electrophoretic analysis of the peak fractions is shown in Fig. 2. Peak C was chosen as antigen for the preparation of the two antisera by intravenous injections in two rabbits. Antibodies obtained were titrated in both cases by immunodiffusion and in indirect ELISA (Fig. 4). Specificity was examined by immunodiffusion and ELISA on heat-treated extracts of reference strains listed in Table 1. Similar results were obtained for the two antisera which were both specific to AG3 (Fig. 1 and Table 2). Characterisation tests were done by the two methods directly on sclerotia of tubers of different cultivars and origins harvested in 1991 (Table 3). The purified antigens appeared to be of a complex nature (peptides-polysaccharides) and were very immunogenic. Antibodies raised against them were sufficiently specific as to allow the identification ofR. solani AG3 sclerotica on tubers.相似文献
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74.
Sylvie Pirson Lise Geerinckx Leslie Bosseler Jules Simard Tom Hellebuyck 《Journal of Exotic Pet Medicine》2018,27(3):6-10
A 12-year-old, female mangrove snake (Boiga dendrophila melanota) was presented with a 1-month history of anorexia, lethargy, and progressive distention of the caudal coelomic cavity. Based on ultrasonographic and cytological examination, an ovarian neoplasia was considered to be the presumptive antemortem diagnosis. Histological examination confirmed the diagnosis of a granulosa cell tumor (GCT) with metastatic tumors in the coelomic fat bodies. Four months following oophorectomy and surgical removal of the distant metastasis, the snake was euthanized because of sudden onset of lethargy, cardiomegaly, and dyspnea. Postmortem examination revealed the presence of metastatic tumors in the lung, liver, and kidneys. Primary ovarian neoplasms are relatively rare in reptiles. Although GCTs have been documented in snakes, definitive diagnosis is typically determined through postmortem histopathological examination. The present case describes a suitable antemortem diagnostic approach of a malignant GCT in a mangrove snake with distant metastases. 相似文献
75.
C. Grosclaude R. Olivier J.-C. Pizzuto Corinne Romiti Sylvie Madec 《Forest Pathology》1988,18(7):385-390
Application of the technique of trapping Ceratocystis fimbriata f. platani for the study of the persistance in affected trees . The study of the persistance of Ceratocystis fimbriata f. platani in affected trees is achieved by trapping of the fungus which is carried out on small branches of London plane, stripped of their bark. If C. fimbriata is present in samples of wood to be tested, it becomes visible after a few days when numerous perithecia form on the trap. Trapping the fungus by this method has been systematically achieved with young, artificially inoculated trees: in many cases, C. fimbriata persists in the wood after a period of about 19 to 22 months. 相似文献
76.
77.
Breyer J Wemheuer WM Wrede A Graham C Benestad SL Brenig B Richt JA Schulz-Schaeffer WJ 《Veterinary microbiology》2012,157(1-2):23-31
Prion diseases are diagnosed by the detection of their proteinase K-resistant prion protein fragment (PrP(Sc)). Various biochemical protocols use different detergents for the tissue preparation. We found that the resistance of PrP(Sc) against proteinase K may vary strongly with the detergent used. In our study, we investigated the influence of the most commonly used detergents on eight different TSE agents derived from different species and distinct prion disease forms. For a high throughput we used a membrane adsorption assay to detect small amounts of prion aggregates, as well as Western blotting. Tissue lysates were prepared using DOC, SLS, SDS or Triton X-100 in different concentrations and these were digested with various amounts of proteinase K. Detergents are able to enhance or diminish the detectability of PrP(Sc) after proteinase K digestion. Depending on the kind of detergent, its concentration - but also on the host species that developed the TSE and the disease form or prion type - the detectability of PrP(Sc) can be very different. The results obtained here may be helpful during the development or improvement of a PrP(Sc) detection method and they point towards a detergent effect that can be additionally used for decontamination purposes. A plausible explanation for the detergent effects described in this article could be an interaction with the lipids associated with PrP(Sc) that may stabilize the aggregates. 相似文献
78.
Analyses of recent classical swine fever (CSF) epidemics in the European Union have shown that silent circulation of CSF virus (CSFV) occurs before the first outbreak is detected and this may lead to a large epidemic. However, severity of CSF disease signs may be linked with efficacy of disease transmission, the most severely affected animals having a higher infectivity than the less affected ones. The purpose of this study was to combine disease transmission quantification methods with CSF clinical signs quantification tools to investigate whether clinical signs, considered as infectivity markers, may allow us to calculate reliable estimates for disease transmission parameters. Data from three transmission experiments were used, varying according to the viral strain (Eystrup or Paderborn) and to the contact structure between experimentally inoculated and contact animals (direct or indirect contact). Within- and between-pen basic reproduction ratios (R0) were compared using viraemia data or clinical data. Between-pen R0 estimates were close and not significantly >1, with either strain or computation mode (using viraemia or clinical data). Conversely, within-pen R0s (Paderborn strain) computed using clinical data appeared higher than the estimates obtained using viraemia data. A models comparison (Bayes information criterion) showed a better fit of the clinical-based models, for both strains. This suggests that, in affected herds, the most severely affected animals could play a prominent role in CSFV transmission. 相似文献
79.
80.
Comparison of sandy soils suppressive or conducive to ectoparasitic nematode damage on sugarcane 总被引:1,自引:0,他引:1
ABSTRACT Two South African sandy soils, one suppressive and the other conducive to ectoparasitic nematode damage on monoculture sugarcane, were compared. Analysis of field transects indicated that the suppressive soil displayed a comparatively higher population of the weak ectoparasite Helicotylenchus dihystera, whose predominance among ectoparasitic nematodes is known to limit yield loss caused by more virulent phytonematodes. Soil type was identical at both sites (entisols), but the suppressive soil had a higher organic matter content and a lower pH, which correlated with H. dihystera population data. In contrast, microclimatic differences between the two field sites were unlikely to be responsible for the suppressive or conducive status of the soils, as shown in a greenhouse experiment. The two soils exhibited a bacterial community of the same size but with different genetic structures, as indicated by automated ribosomal intergenic spacer analysis (RISA). The number of culturable fluorescent pseudomonads was higher for the conducive soil, probably because extensive root damage caused by ectoparasitic nematodes favored proliferation of these bacteria. This study shows that apparently small differences in soil composition between fields located in the same climatic area and managed similarly can translate into contrasted nematode communities, ectoparasitic nematode damage levels, and sugarcane yields. 相似文献