Difference in virulence between Staphylococcus aureus isolates causing gangrenous mastitis versus subclinical mastitis in a dairy sheep flock     

Eric Vautor  Joshua Cockfield  Caroline Le Marechal  Yves Le Loir  Marl��ne Chevalier  D. Ashley Robinson  Richard Thiery    Jodi Lindsay 《Veterinary research》2009,40(6)

Staphylococcus aureus mastitis in dairy sheep ranges from subclinical mastitis to lethal gangrenous mastitis. Neither the S. aureus virulence factors nor the host-factors or the epidemiological events contributing to the different outcomes are known. In a field study in a dairy sheep farm over 21 months, 16 natural isolates of S. aureus were collected from six subclinical mastitis cases, one lethal gangrenous mastitis case, nasal carriage from eight ewes and one isolate from ambient air in the milking room. A genomic comparison of two strains, one responsible for subclinical mastitis and one for lethal gangrenous mastitis, was performed using multi-strain DNA microarrays. Multiple typing techniques (pulsed-field-gel-electrophoresis, multiple-locus variable-number, single-nucleotide polymorphisms, randomly amplified polymorphic DNA, spa typing and sas typing) were used to characterise the remaining isolates and to follow the persistence of the gangrenous isolate in ewes’ nares. Our results showed that the two strains were genetically closely related and they shared 3 615 identical predicted open reading frames. However, the gangrenous mastitis isolate carried variant versions of several genes (sdrD, clfA-B, sasA, sasB, sasD, sasI and splE) and was missing fibrinogen binding protein B (fnbB) and a prophage. The typing results showed that this gangrenous strain emerged after the initial subclinical mastitis screening, but then persisted in the flock in the nares of four ewes. Although we cannot dismiss the role of host susceptibility in the clinical events in this flock, our data support the hypothesis that S. aureus populations had evolved in the sheep flock and that S. aureus genetic variations could have contributed to enhanced virulence.  相似文献   

Physics. Superconductivity with a twist     

Rice M 《Science (New York, N.Y.)》2006,314(5803):1248-1249

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Structure-activity relationship development of dihaloaryl triazole compounds as insecticides and acaricides. 1. Phenyl thiophen-2-yl triazoles     

Cudworth DP  Hegde VB  Yap MC  Guenthenspberger KA  Hamilton CT  Pechacek JT  Johnson PL  Bis SJ  Tisdell FE  Dripps JE  Bruce TJ  Dintenfass LP  Gifford JM  Karr LL  Kempe MK  McCormick DC  Schoonover JR 《Journal of agricultural and food chemistry》2007,55(18):7517-7526

An extended lipophilic system that incorporated some key elements of first-generation 2,6-dihaloaryl actives, such as 1, demonstrated desirable efficacy against chewing insects as well as sap-feeding insects. These four-ring systems, based on 2, were accessed primarily via Suzuki couplings of halothiophene derivatives with appropriately substituted boronic acids. In particular, phenylthiophene systems that incorporated haloxyether groups, such as those in 3, 4, and 5, had the broadest spectrum of activity across chewing and sap-feeding insect pests. Expansion of this structure-activity relationship to include compounds with differing substitution patterns on the thiophene-C-ring and aryl-D-rings was undertaken. The synthesis and insecticidal activity of 3-aryl-5-(thiophen-2-yl)-1-methyl-1H-[1,2,4]triazoles will be described.  相似文献   

Resistance screening of <Emphasis Type="Italic">Coffea</Emphasis> spp. accessions for <Emphasis Type="Italic">Pratylenchus coffeae</Emphasis> and <Emphasis Type="Italic">Radopholus arabocoffeae</Emphasis> in Vietnam     

Phap?Q.?Trinh  Wim?M.L.?Wesemael  Hung?A.?Tran  Chau?N.?Nguyen  Maurice?MoensEmail author 《Euphytica》2012,185(2):233-241

Coffee varieties with resistance for the plant-parasitic nematodes Pratylenchus coffeae and Radopholus arabocoffeae are limited in Vietnam. A selection of imported varieties and high yield varieties of Arabica coffee in Vietnam were evaluated for resistance to both plant-parasitic nematode species in Northern Vietnam. The same experiments were carried out with hybrid arabica coffee, three selected clones of Coffea canephora and one clone of Coffea excelsa in the Western Highland of Vietnam. The screened coffee accessions from Ethiopia (KH1, KH13, KH20, KH21, KH29, and KH31) were susceptible and good host for P. coffeae. Also accessions 90P4 (Portugal) and Oro azteca (Mexico) had a reproduction factor Rf > 1. Pluma Hidalgo (Mexico), 90/6 (Vietnam), 90P3 (Portugal), 90P2 (Vietnam), Variedad (Mexico), 90T (Portugal), and Garnica (Mexico) were poor hosts (Rf < 1) but not tolerant to P. coffeae, expressed by a reduction of root weight compared to untreated control plants. Most of the coffee accessions tested in Northern Vietnam were intolerant to R. arabocoffeae, except 90T which showed no reduction of root weight, even at high initial nematode densities (4,000/pot). Good hosts for R. arabocoffeae were Variedad, KH1, KH21, KH29, KH20, KH31, and KH13 with Rf > 1. Pluma Hidalgo, 90/6, 90P3, 90P2, 90T, Oro azteca, and Garnica were poor hosts (Rf < 1). In the Western Highland experiment, all arabica coffee accessions were susceptible for P. coffeae with Rf ranging from 1.41 to 1.59. Tolerance to P. coffeae was found in C. liberica var. Dewevrei, Hong34 and Nhuantren. Coffea excelsa, Hong34, Nhuantren, and H1C19 were tolerant to R. arabocoffeae at the highest inoculation density (4,000 nematodes/pot). The most susceptible accessions were Nhuantren and K55. Resistance (Rf < 1) to R. arabocoffeae was found in C. liberica var. Dewevrei and Hong34. This article reports on the first screening for resistance and tolerance to P. coffeae and R. arabocoffeae in coffee accessions in Vietnam and shows promising results for enhanced coffee-breeding.  相似文献   

Identification and molecular characterization of a new β-1,4-endoglucanase gene (Ha-eng-1a) in the cereal cyst nematode Heterodera avenae     

Haibo Long  Huan Peng  Wenkun Huang  Gaofeng Wang  Bingli Gao  Maurice Moens  Deliang Peng 《European journal of plant pathology / European Foundation for Plant Pathology》2012,134(2):391-400

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Isozyme polymorphism of Rosa spp. and cultivar identification     

Cédric Grossi  Olivier Raymond  Maurice Jay 《Euphytica》1997,98(1-2):11-19

In order to study the polymorphism of the enzyme systems of rose cultivars, experimental conditions were determined to simultaneously extract three systems: esterase (EST), leucine aminopeptidase (LAP) and superoxide dismutase (SOD) which gave up to 9, 7 and 9 bands, respectively. The influence of environmental conditions on the polymorphism level was taken into account. Finally, the computation of the Jaccard distances from the distribution of the isozyme bands led to the improvement of the identification process within an Ancient Rose cultivar collection. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Influences of Aporrectodea trapezoides and A. rosea (Lumbricidae) on the uptake of nitrogen and yield of oats (Avena fatua) and lupins (Lupinus angustifolius): The 7th international symposium on earthworm ecology · Cardiff · Wales · 2002     

Geoff H. Baker  Maurice Amato  Jeff Ladd 《Pedobiologia》2003,47(5-6):857-862

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Phenol antioxidant quantity and quality in foods: beers and the effect of two types of beer on an animal model of atherosclerosis     

Vinson JA  Mandarano M  Hirst M  Trevithick JR  Bose P 《Journal of agricultural and food chemistry》2003,51(18):5528-5533

The free phenols have been measured in 15 lagers, 6 porters and ales, and 11 light and nonalcoholic beers. Phenols were measured colorimetrically using an oxidation-reduction reaction with Folin-Ciocalteu reagent and catechin as the standard. The order of phenol concentration was ales > lagers > low calorie > nonalcoholic. The quality of antioxidants of the major phenols in beers and the quality of beer antioxidants were measured by (1) dose-response inhibition of lower density lipoprotein oxidation and (2) concentration of phenols in the beers at which 50% of the peroxide was destroyed in a luminescent assay for antioxidant activity. The beers' lipoprotein antioxidant quality was clearly superior to that of vitamin antioxidants and to that of the phenol ingredients, suggesting synergism among the antioxidants in the mixture. The average per capita consumption of beer in the United States in 2000 was 225 mL/day, equivalent to 42 mg/day of catechin equivalents. Beer provides more antioxidants per day than wine in the U.S. diet. A dark beer and a lager beer were given at two concentrations to cholesterol-fed hamsters, an animal model of atherosclerosis. At the high dose ((1)/(2)-diluted beer) both lager and dark beer significantly inhibited atherosclerosis compared to a control of 2% alcohol. At the high dose, lager significantly decreased cholesterol and triglycerides, and both beers acted as in vivo antioxidants by decreasing the oxidizability of lower density lipoproteins. At the low dose ((1)/(10)-diluted beer) only the lager beer significantly decreased atherosclerosis compared to the 0.4% alcohol control. The polyphenols in the beers appear to be responsible for the benefits of beer in this model. Lager beer inhibited atherosclerosis at a human equivalent dose in this hamster model of atherosclerosis.  相似文献   

Chemical Composition of Rainwater Near Two Historical Monuments The Thann Collegiate (Alsace,France) and the Tours Cathedral (Indre et Loire,France)     

Millet  Maurice  Wortham  Henri  Mirabel  Philippe  Flori  Jean-Paul  Lakkis  Dominique  Leroy  Maurice 《Water, air, and soil pollution》2001,132(1-2):105-126

In the present study, included within the framework of a Franco-German Research Program for Conservation of HistoricalMonuments, the chemical composition of rainwater was investigated in Thann (Alsace, France) and in Tours (Indre etLoire, France) between 1992 and 1993. A total of 78 and 24samples, respectively, were collected, near the Thann collegiateand the Tours cathedral on a weekly basis and analysed for Cl^-, NO₃ ^-, SO₄ ^2-, Na⁺, NH₄ ⁺, K⁺, Mg²⁺ and Ca²⁺. Results showpH ranged from 3.60 to 6.58 and from 5.49 to 7.01 for Thann andTours, respectively. In Thann, SO₄ ^2- is the major anion and rainwater acidity is neutralised by compounds ofterrigenic origin which come from the soil of the upper Rhinevalley (Ca²⁺; ‘loess’) and the potash mines of Alsace. In Tours, SO₄ ^2- is also the major anion and the acidity is neutralised partially by atmospheric ammonia and partially by compounds of terrigenic origin and by dust fromthe erosion of the cathedral and the works of restoration, in the form of CaCO₃.  相似文献   

Comparative morphology of epicorneal conjunctival membranes in rabbits and human pterygium   总被引：1，自引：1，他引：0  

Maurice Roze  Bernard Ridings†  Marie Lagadic‡ 《Veterinary ophthalmology》2001,4(3):171-174

A rarely described ocular lesion in the rabbit is presented following the observation of four cases. It is a membrane of conjunctival origin that advances progressively, without adhering, towards the center of the cornea. Clinically the lesion in rabbits looks like pterygium in man, but with several differences: in rabbits, the conjunctival fold is absolutely free and does not penetrate into the superficial corneal layers. It originates from all the limbal circumference in a symetric growth. The cornea itself remains unaltered. The fold consists of fibroblasts and collagen. The microscopic findings suggest the lesion is possibly of a collagenous dysplasia.  相似文献