Pathogenicity of porcine enterotoxigenic Escherichia coli that do not express K88, K99, F41, or 987P adhesins.     

T A Casey  B Nagy  H W Moon 《American journal of veterinary research》1992,53(9):1488-1492

Three-week-old weaned and colostrum-deprived neonatal (less than 1 day old) pigs were inoculated to determine the pathogenicity of 2 enterotoxigenic Escherichia coli isolates that do not express K88, K99, F41, or 987P adhesins (strains 2134 and 2171). Strains 2134 and 2171 were isolated from pigs that had diarrhea after weaning attributable to enterotoxigenic E coli infection. We found that both strains of E coli adhered in the ileum and caused diarrhea in pigs of both age groups. In control experiments, adherent bacteria were not seen in the ileum of pigs less than 1 day old or 3 weeks old that were noninoculated or inoculated with a nonpathogenic strain of E coli. These control pigs did not develop diarrhea. Antisera raised against strains 2134 and 2171 and absorbed with the autologous strain, grown at 18 C, were used for bacterial-agglutination and colony-immunoblot assays. Both absorbed antisera reacted with strains 2134 and 2171, but not with strains that express K99, F41, or 987P adhesins. A cross-reaction was observed with 2 wild-type K88 strains, but not with a K12 strain that expresses K88 pili. Indirect immunofluorescence with these absorbed antisera revealed adherent bacteria in frozen sections of ileum from pigs infected with either strain. We concluded that these strains are pathogenic and express a common surface antigen that may be a novel adhesin in E coli strains that cause diarrhea in weaned pigs.  相似文献   

Major antigenic groups of rabies virus in Canada determined by anti-nucleocapsid monoclonal antibodies   总被引：5，自引：0，他引：5  

W A Webster  G A Casey  K M Charlton 《Comparative immunology, microbiology and infectious diseases》1986,9(1):59-69

A total of 123 rabies virus isolates from various geographical areas in Canada were characterized by a panel of 43 anti-nucleocapsid monoclonal antibodies. Four major antigenic groups are found in terrestrial mammals: "Canadian Arctic" from Ontario, Quebec and the Northwest Territories; "south-eastern Georgian Bay" from Ontario; "south mid-central skunk" from Alberta, Saskatchewan and Manitoba; and "Brook's, Alberta skunk" from a restricted area in Alberta. Bat isolates can be divided into 4 major antigenic groups: "B-1" in Eptesicus fuscus from Ontario; "B-2" in a variety of bat species from British Columbia eastward into Ontario; "B-3" in Myotis spp. from Ontario and New Brunswick; and "B-4" in E. fuscus from Alberta and Saskatchewan. A single case of bat to horse transmission of rabies virus is recorded. These street isolates are compared with isolates of fixed virus. Epidemiological aspects are discussed.  相似文献   

Atlantic Canada. Bat-induced rabies in terrestrial mammals in Nova Scotia and Newfoundland          下载免费PDF全文

Webster WA  Casey GA  Charlton KM 《The Canadian veterinary journal. La revue veterinaire canadienne》1989,30(8):679

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Cerebral Blastomyces dermatitidis infection in a cat     

Smith JR  Legendre AM  Thomas WB  LeBlanc CJ  Lamkin C  Avenell JS  Wall JS  Hecht S 《Journal of the American Veterinary Medical Association》2007,231(8):1210-1214

CASE DESCRIPTION: An 8-year-old domestic shorthair cat was evaluated because of signs of depression, circling, and visual deficits. CLINICAL FINDINGS: The cat had no cutaneous lesions, and results of an ophthalmologic examination and thoracic radiography were within reference limits. Computed tomography of the brain revealed a mass lesion involving the right parietal, temporal, and occipital lobes; the mass was in broad-based contact with the skull and smoothly marginated and had strong homogenous enhancement after contrast agent administration. During craniectomy, samples of the mass were collected for cytologic and histopathologic evaluations and microbial culture. A diagnosis of Blastomyces dermatitidis-associated meningoencephalitis with secondary pyogranulomatous inflammation was made. TREATMENT AND OUTCOME: Amphotericin B (0.25 mg/kg [0.11 mg/lb], IV) was administered on alternate days (cumulative dose, 1.75 mg/kg [0.8 mg/lb]). To minimize the risk of nephrotoxicosis, assessments of serum biochemical variables (urea nitrogen and creatinine concentrations) and urinalyses were performed at intervals. The third dose of amphotericin B was postponed 48 hours because the cat became azotemic. The cat subsequently received fluconazole (10 mg/kg [4.5 mg/lb], PO, q 12 h) for 5.5 months. Six months after discontinuation of that treatment, the cat appeared healthy and had no signs of relapse. CLINICAL RELEVANCE: Brain infection with B dermatitidis is typically associated with widespread disseminated disease. The cat of this report had no evidence of systemic disease. Blastomycosis of the CNS should be considered as a differential diagnosis for brain lesions in cats from areas in which B dermatitidis is endemic.  相似文献   

Prey preferences of notonectids towards larval mosquitoes across prey ontogeny and search area     

Arpita Dalal  Ross N Cuthbert  Jaimie TA Dick  Susmita Gupta 《Pest management science》2020,76(2):609-616

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Individual-based modeling highlights the importance of mortality and landscape structure in measures of functional connectivity     

Day  Casey C.  Zollner  Patrick A.  Gilbert  Jonathan H.  McCann  Nicholas P. 《Landscape Ecology》2020,35(10):2191-2208

Landscape Ecology - Functional landscape connectivity is vital for the conservation of wildlife species. Landscape connectivity models often overlook factors such as mortality and asymmetry in...  相似文献   

工厂化水产养殖水质监测系统   总被引：1，自引：0，他引：1  

肖瑞超  位耀光  他旭翔  张龙 《水产学杂志》2017,(5):51-56

工厂化水产养殖的密度高、风险大,养殖对象对pH、溶解氧、温度、氨氮、亚硝酸盐等水质参数的变化敏感,受影响严重,监测水质参数极为重要。本文针对工厂化水产养殖水质监测特点和需求,研发了工厂化水产养殖水质监测系统。分析研究pH、溶解氧、温度、亚硝酸盐等水质参数的阈值,设计水质监测数据无线采集节点和基于Zigbee的无线监测网络,建立水质监测系统软件平台。结果表明,该系统能够实现工厂化水产养殖水质实时监测,保证生产安全,提高水产养殖生产效率。  相似文献   

黄土耕作坡面溅蚀过程中微地形响应特征   总被引：4，自引：0，他引：4  

塔娜  王健  张慧荟  田龙  张青峰 《水土保持通报》2016,36(1):110-114

[目的]探究60mm/h雨强下不同耕作坡面在溅蚀阶段的微地形变化特征,为黄土坡地水土保持耕作方式布设提供科学依据。[方法]在室内人工模拟降雨试验的基础上,采用激光扫描量测方法分别获取溅蚀前后4种不同耕作方式(人工锄耕、人工掏挖、等高耕作、耙磨整平)黄土坡面微地形相对高程,并对能反映微地形变化的高精度M-ΔDEM进行了分析。[结果]不同耕作措施下坡面微地形均具有较弱的空间变异,其空间分异主要受耕作措施的影响;降雨对微地形具有一定的夷平效应,且不同耕作坡面在1~1.3m尺度范围内均表现出侵蚀平衡现象;不同耕作微地形对溅蚀均具有阻滞作用,其中人工掏挖和等高耕作具有较强的水土保持作用。[结论]微地形水系分维能较好地反映复杂的微地形特征,而坡面耕作方式是溅蚀过程中微地形时空变异分布状况的控制性因子。  相似文献   

大型灯泡贯流式泵站振动研究概述     

王新  李同春  塔娜 《中国农村水利水电》2009,(2):83-85

机组和泵房的振动是泵站运行中最为常见的问题,直接影响泵站的安全可靠运行。对大型灯泡贯流式泵站振动研究现状和抗振安全评价计算分析方法作了详细的介绍,对研究机组振动诱发泵房振动的共振校核法、拟静力法、谐响应求解法和瞬态动力时程法等进行了阐述,并对这几种方法进行了分析比较,就其存在的问题作了总结概述。  相似文献   

利用沙尘暴进行荒漠化草原表土再造技术原理及实践     

赵山志  田青松  那日苏  王海  联华  塔娜  乌兰 《现代农业科技》2011,(3):321-323

依据风沙学原理,利用沙尘暴现象对内蒙古荒漠草原进行了表层土壤再造试验。采用地表撒松散杂草(秸秆)后用尼龙网罩固定的方法,拦截沙尘暴所携带的尘土。再造后的土壤掩埋了裸露的植物根系和地表面的砾石,比对照土壤有效锌增加114.8%、有机质增加33.3%、全氮增加77.1%、有效磷增加150.0%、速效钾增加7.8%、pH值降低了1.3%。此方法为如何利用沙尘暴这一自然现象开辟了新的思路。  相似文献