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1.
单核细胞增生李斯特氏菌(Listeria monocytogens,LM,简称为单增李斯特氏菌)是食品卫生上重要的病原菌。它广泛存在于自然界,可导致人和动物脑膜炎、流产、败血症等,病死率高达30%-70%,是目前人类最重要的食物源性病原菌之一。由于该菌生长温度范围较广,在  相似文献   

2.
PCR扩增单增李斯特氏菌ActA基因,纯化后克隆到pMD 18T simple vector 中,以BamHI和EcoRI双酶切克隆载体pMD-18T/ActA,再将其亚克隆到表达载体pGEX-3X中,获得重组质粒 pGEX-3X/ActA,转化E.coli BL21(DE3)细胞,IPTG诱导融合蛋白(GST-ActA)表达,Western blot分析表明该蛋白可与单增李斯特氏菌多克隆抗体发生特异性反应.试验采用Glutathione Sepharose 4B亲合层析纯化融合蛋白.对单增李斯特氏菌ActA的原垓表达与纯化的研究为单增李斯特氏菌诊断试剂的研制及Acth的免疫原性研究奠定了基础.  相似文献   

3.
单增李斯特菌是乳粉中常见的致病菌之一。为了解不同水活性(Aw)干乳粉、复水乳粉和热冲调乳粉中单增李斯特菌的生存特性,通过人工方法将单增李斯特菌添加于不同Aw的干奶粉、复水奶粉中,并在不同温度或pH条件下培养,通过菌落计数来分析单增李斯特菌的生存特性。结果显示:在4 ℃条件下,单增李斯特菌可在较低Aw(0.81、0.92)的干奶粉中长期保持生长活力,并且当Aw较高(0.96)时,会有增长趋势;在25 ℃条件下,干奶粉中的单增李斯特菌的生长活力很快减退,细菌处于亚损伤状态。复水奶粉中的单增李斯特菌能够生长的温度为-1.5~37 ℃,在pH4.4~8.0的复水奶粉中,高温条件下(30 ℃)比在低温条件下(4 ℃)生长快,但在低温条件下,对酸碱的耐受程度比在高温条件下大。单增李斯特菌在复水的高糖高脂奶粉中比原料奶粉中对热的耐受力强。结果表明,高温条件更易使干奶粉中单增李斯特菌生长活力减退,复水奶粉如果污染单增李斯特菌,在低温条件下贮存则能够控制单增李斯特菌的生长,高糖高脂成分可提高单增李斯特菌的热抵制能力。本研究为乳粉中单增李斯特菌的风险评估和关键控制措施的制定提供了依据。  相似文献   

4.
三明市四种销售畜禽肉品中李斯特氏菌污染情况调查   总被引:1,自引:0,他引:1  
为了解三明市畜禽肉类中李斯特氏菌的污染情况。2000年6月至2001年5月,采集市区菜市场销售的畜禽肉类,按GB4789-94进行李斯特氏菌分离、鉴定。结果从4种畜禽肉类中检出了李斯特氏菌,检出率为12.2%(49/403),其中猪肉检出率最高为18.2%,鸡肉次之,鸭肉最低为3.8%,(p<0.01)。一年四季均有李斯特氏菌检出,秋季较高,(p>0.05)。本次仅从猪肉中检出1株单核细胞增生李斯特氏菌,占2.0%,其余44株为格氏李斯特氏菌,占89.9%,默氏李斯特氏菌4株占8.2%。  相似文献   

5.
李斯特氏菌属特异单抗试剂的研制与鉴定   总被引:4,自引:1,他引:3  
以单核细胞增生症李斯特氏菌制备免疫原,应用常规淋巴细胞杂交瘤技术产生杂交瘤细胞,经ELISA试验筛选,得到6株分泌特异性单抗的细胞系,分别命名为C11、B18、B5、B6、D2、C5。单抗与标准菌株反应结果显示,C11、B18、B5三株单抗能与全部24株李斯特氏菌发生反应,所试菌株中包括L.M.14株,以及无害李斯特氏菌、伊凡诺夫李斯特氏菌、西里杰氏李斯特氏菌、威斯福尔氏李斯特氏菌和格氏李斯特氏菌  相似文献   

6.
李斯特氏菌病或称李氏杆菌病,是一种散发性传染病,以全身血液中毒-败血症和子宫炎及流产为特征.本病的病原为单核细胞增多性李氏杆菌(或单核细菌增多性李斯特氏菌、产单核细胞李氏杆菌).  相似文献   

7.
为快速检测食品中的金黄色葡萄球菌(SA)、单增李斯特氏菌(LM)和副溶血性弧菌(VP),根据各菌的相关基因设计引物,分别扩增金黄色葡萄球菌的耐热核酸酶基因-nuc、单增李斯特氏菌溶血素O上的hlyA基因和副溶血性弧菌的热稳定直接溶血素基因-tdh,建立一种MPCR快速检测食品中致病菌的方法,结果表明,三条特异性扩增片段分别为279bp、243bp和202bp,经DNA测序证明其序列与模板被扩增片段一致。该方法具有良好的灵敏性和特异性。  相似文献   

8.
高度特异的李斯特菌单抗试剂的研制及鉴定   总被引:4,自引:0,他引:4  
以单核细胞增生李斯特菌制备免疫原,应用淋巴细胞杂交瘤技术,建立了3株能稳定分泌抗单核细胞2增生李斯特菌,无害李斯特菌和格氏李斯特菌的单克隆抗体的细胞系,分别是LJ10A,LM11和LB5,而与其余种的李斯特菌和属外细菌不发生交叉反应。  相似文献   

9.
为鉴定分离自新疆北疆绵羊单核细胞增生李斯特氏菌,本研究采用多重PCR方法,鉴定来自病发地区部分羊场的发病绵羊、健康绵羊、羊舍环境和乌鸦粪分离的30株李斯特氏菌分离株的8株单核细胞增生李斯特氏菌分离株血清型。结果为4株发病绵羊株有3株鉴定为单核细胞增生李斯特氏菌,血清型为1/2a或4b,1株为非单核细胞增生李斯特氏菌;5株健康绵羊株血清型为1/2a;其余来自羊舍水源的3株、乌鸦粪的2株及健康绵羊16株为非单核细胞增生李斯特氏菌,表明来自发病绵羊、健康绵羊及参考菌株LM血清型之间具有相关性。  相似文献   

10.
利用PCR技术从单增李斯特氏菌中扩增出actA基因,将PCR产物纯化后克隆到pMD 18Tsimple vector中,成功构建出克隆载体pMD-18T/actA。以BamHⅠ和EcoRⅠ分别双酶切pMD-18T/ActA和表达载体pGEX-3X,将纯化的actA基因亚克隆到表达载体pGEX-3X。构建的重组表达载体pGEX-3X/ActA转化到E.coli BL21(DE3)中,IPTG诱导表达,表达产物进行SDS-PAGE分析,可见约120 ku外源蛋白带,Western blot分析表明该蛋白可与单增李斯特氏菌多克隆抗体发生特异性反应。该研究为ActA的生物学特性和功能的研究及诊断试剂的研制奠定了基础。  相似文献   

11.
12.
本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。  相似文献   

13.
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。  相似文献   

14.
REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air.  相似文献   

15.
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo.  相似文献   

16.
用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10~0.82μg/g。表明:蜂蜜应视为天然富硒营养品。  相似文献   

17.
Fractures of the anconeal process of 5 pigs ranging in age from 4 to 8 months were studied radiographically and histologically. Clinically, animals with a fracture of the anconeal process had a "tight," restricted gait. In pigs at 4.5 months of age, a radiolucent line through the base of the anconeal process was composed of fibrocartilage, fibrous connective tissue, and hyaline cartilage. Subperiosteal proliferation of woven bone was located along the cranial surface of the olecranon, adjacent to the base of the anconeal process. In older animals, the radiolucent line through the anconeal process contained variable amounts of fibrous connective tissue and fibrocartilage. The proliferation of subperiosteal bone at the base of the anconeal process formed a "buttress callus" which retained a radiolucent area between the callus and the proximal surface of the anconeal process. The latter region of radiolucency was continuous with the transversely oriented line that traversed the base of the anconeal process.  相似文献   

18.
为贯彻落实《兽药生产质量管理规范》(简称《兽药GMP》),进一步推动兽药GMP实施进程,我部制定了《兽药生产质量管理规范检查验收办法》,现予公告。本公告自2003年6月1日起施行。附件:兽药生产质量管理规范检查验收办法二○○三年四月十日第一章 总则 第一条 为推动《兽药生产质量管理规范》(以下简称兽药GMP)的实施,规范兽药GMP检查验收工作,制定本办法。 第二条 农业部负责全国兽药GMP管理和检查验收工作;负责制修订兽药GMP检查验收管理规定;负责兽药GMP检查员队伍建设和监督管理工作,负责国际兽药贸易中GMP互认工作。 …  相似文献   

19.
以国际标准强毒R株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离MG,并收集感染鸡所产蛋分离MG。结果表明,人工感染48小时后上、下呼吸道及肺已被全面感染,96小时气囊已被感染,120小时输卵管已能分离到MG,卵巢始终分离不到MG。人工感染鸡自144小时便能在其所产蛋中分离出MG。药物治疗能在72小时内消除感染,油乳剂苗则需24天后逐渐降低蛋内MG分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内MG,但以研制的种蛋浸泡剂药浴效果为最好。  相似文献   

20.
乳酸杆菌益生作用机制的研究进展   总被引:2,自引:0,他引:2  
乳酸杆菌作为益生菌广泛用于人和动物。本文综述了乳酸杆菌改善宿主健康的机制。乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道。文章重点讨论了乳酸杆菌表面成分(表面蛋白、脂磷壁酸和肽聚糖)与肠道受体(C型凝集素受体、Toll样受体和 Nod样受体),阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制。  相似文献   

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