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51.
Gérardin J Lalioui L Jacquemin E Le Bouguénec C Mainil JG 《Veterinary microbiology》2000,76(2):175-184
Six hundred and nine necrotoxigenic Escherichia coli type 1 and 2 (NTEC1 and NTEC2) and non-NTEC isolated in Western and Southern Europe, North Africa and Canada from diseased calves, pigs, humans, poultry, and 55 isolated from asymptomatic calves were studied for the identification of afa-related sequences to the recently described afa-7 and afa-8 gene cluster variants from two bovine Escherichia coli (Lalioui et al., 1999). Colony hybridization and PCR assays for the afaD-7, afaE-7, afaD-8 and afaE-8 identified the afa-related sequences to the afa-8 gene cluster in most (67/79; 85%) of the E. coli positive with the Afa-f family probe and in 14 additional strains negative with the Afa-f probe. No E. coli was positive for the afa-7 gene cluster. The existence of afa-8 positive strains was thus confirmed among bovine E. coli and for the first time among porcine, poultry and human E. coli. Sequencing of the afaE-8 amplicon of nine strains from the different host species showed a high degree of conservation (>95% at the DNA level; >92% at the amino-acid level). The afa-8 gene cluster was more frequent in E. coli from diseased calves (18%) than from piglets (12%), humans (6%) and poultry (5%). Bovine NTEC2 (26%) were more frequently positive than NTEC 1 (20%) and non-NTEC (11%). E. coli isolated from asymptomatic calves were rarely positive: one NTEC2 (3%) and no non-NTEC. The afa-8 gene cluster was located on the Vir plasmid in 11/23 NTEC2, but no plasmid localization was detected in NTEC1 or non-NTEC. 相似文献
52.
Albina E Mesplède A Chenut G Le Potier MF Bourbao G Le Gal S Leforban Y 《Veterinary microbiology》2000,77(1-2):43-57
In early 1992, a CSF epizootic was clinically recognised in a wild boar population of approximately 1300 animals within an area of 250km(2) located in the east of France. In order to check the CSF situation in wild boars outside this area, a serological survey was carried out in the rest of France, for 8 consecutive years (1991-1998). This paper reports on the results obtained during this survey which included wild boars shot during the hunting period but also boars reared within fences. Around 1000-2700 sera a year were tested for the presence of antibodies to classical swine fever virus (CSFV) and also to Aujeszky's disease virus (ADV). Out of 12025 sera tested over the whole period, 80 wild boars were found positive for CSF antibodies. Sixty of them were collected on wild boars shot during the years 1992-1994 in the epizootic area located in east of France and 10 were collected in Corsica during the years 1994-1996. The last four positive samples were single reactors coming from areas or farms, which were thereafter confirmed to be serologically negative. These results together with the fact that no disease has been reported so far illustrate that the French wild boar population is probably not concerned by CSF infection (excepted in the east of France where the disease has now become enzootic). Two hundred and forty nine sera were initially detected as CSF positive but confirmed secondarily as positive for border disease (BD) antibodies. This finding shows that wild boars are also susceptible to infection by ruminant pestiviruses. Four hundred and twenty three wild boars have been found positive for ADV antibodies. In addition, from 1993 to 1995, 909 samples were tested for the presence of antibodies to porcine reproductive and respiratory syndrome virus (PRRSV). Thirty three of them were positive. The results on AD and PRRS antibody detection show that wild boars may constitute a reservoir for various infectious diseases of pigs. 相似文献
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54.
Kunimasa Kawabe Nguyen Thi Ngoc Truc Bui Thi Ngoc Lan Le Thi Thu Hong Masatoshi Onuki 《Journal of General Plant Pathology》2006,72(6):355-359
A quantification system for huanglongbing pathogen using a competitive polymerase chain reaction method and image-analyzing
software were developed to obtain precise results. Significant differences in the quantity of pathogen were thus determined
in leaves of two citrus cultivars commonly cultivated in southern Vietnam. Less pathogen-related DNA was detected from the
tissue of citrus cultivars that are believed to be more tolerant than susceptible cultivars. The quantification system will
be used in studies on pathogen proliferation and movement inside citrus tissue. 相似文献
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合成了3个新的锰-超氧化物歧化酶(Mn-SOD)模拟物Mn(L-Leu)2(1),Mn(L-Val)2·3/2HCl(2)和Mn(L-Phe)2·HCl(3)(L-Leu=L-亮氨酸,L-Val-L-缬氨酸和L-Phe=L-苯丙氨酸).用元素分析、红外光谱对模拟物进行了表征.并用 NBT 光还原法检测了模拟物的SOD活性.结果表明3个模拟物均具有相对较高的类似于 SOD 催化超氧阴离子自由基(O2·-)歧化活性,抑制率为 50%时配合物的浓度,即一个活性单位值 IC50值分别为 0.311、0.274 和 0.378μmol/L.有望成为具有良好应用前景的新型 SOD 模拟物抗拟增产剂而应用于农业生产中. 相似文献
59.
Y Le Fur G Maume M Feuillat B F Maume 《Journal of agricultural and food chemistry》1999,47(7):2860-2864
Yeast autolysis affects membrane stability and induces a release of vacuolar enzymes into the cell cytoplasm. Consecutively, it was important to study the evolution of sterol content in Saccharomycescerevisiae for a fourteen day period of accelerated autolysis. Unesterified and esterified sterols were analyzed both in the biomass and in the autolysis medium. Ten sterols were identified by gas chromatography/mass spectrometry. A second group of six sterols was separated and partially characterized. Among the first group of 10 sterols, a dehydroergosterol was identified as ergosta-5, 7,9(11),22-tetraen-3beta-ol, not yet charaterized in S. cerevisiae. Yeast autolysis induced a decrease of esterified sterol content, especially first intermediates in the sequence of the ergosterol biosynthesis, as zymosterol. In contrast, the yeast autolysis resulted in the release of a low quantity of sterols into the medium. At the end of the fourteenth day of autolysis, 0.015% of the total sterol content of the initial biomass was found in the medium. 相似文献
60.
运用最大熵技术对湖南汽车工业部分重点企业进行了优序分析,并以此为基础,探讨了湖南汽车工业应优先发展的产品,针对性地提出了加快发展湖南汽车工业的若干建议。 相似文献