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7型鸭疫里氏杆菌分离株的鉴定 总被引:14,自引:6,他引:8
鸭疫里氏杆菌(Riemerella anatipestifer,RA)是鸭传染性浆膜炎的致病病原,国际上已报道20个血清型,我们在国内也已发现1、2、6、10、11、13、14、15、17型共9个血清型。对RA分离株的血清型进行鉴定是研究鸭传染性浆膜炎流行病学的内容之一,其结果对于制定有效的免疫程序是至关重要的。2002年,我们从北京某鸭场共分离到4株RA,经鉴定为7型,这在国内尚属首次发现,因而将有关试验情况报告如下。 相似文献
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本文对武进地区鸭传染性浆膜炎进行病原流行病学调查,分析该地区鸭疫里氏杆菌的血清型状况,以期为本地区该病防控找到方法。 相似文献
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15 型鸭疫里氏杆菌分离株的鉴定 总被引:9,自引:3,他引:6
鸭疫里氏杆菌 (Riemerella anatipestifer,RA)是鸭传染性浆膜炎的致病病原 ,国际上已报道 2 1个血清型 [1] ,但有人认为 2 0型参考菌株 6 70 /89不属于 RA[2 ] ,故实际上 RA只有 2 0个血清型。国内已出现 1、2、6、1 0、1 1、1 3、1 4型共 7个血清型 [3 ] 。研究表明 ,RA菌苗具 相似文献
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鸭传染性浆膜炎的防治 总被引:1,自引:0,他引:1
1病原鸭疫里氏杆菌属革兰氏阴性小杆菌,不能运动,无芽胞。国内至少已鉴定出8个血清型,其中以1型和2型引起的发病最多。多种抗菌素对鸭疫里氏杆菌都有效,但因鸭场大量使用抗菌素和该菌本身极易产生耐药性,故临床常用的药物无法控制鸭传染性浆膜炎的发生。当较大规模的鸭场发生鸭传染性浆膜炎时,应采集病料做药敏试验,根据药敏试验结果选择敏感药物进行治疗。2流行病学鸭传染性浆膜炎无严格的季节性,一年四季均可发生。鸭疫里氏杆菌主要感染幼龄鸭,各种品种的鸭均可感染。20~30日龄为发病高峰期。7周龄以上鸭较少发病,成… 相似文献
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鸭传染性浆膜炎的病原为鸭疫里氏杆菌(RA)。它是危害雏鸭的一种急性或慢性败血性传染病。该病原于1904年。由Riemer首次报道了鹅发生本病,并将其称之为“鹅渗出性败血症”。RA的血清型比较复杂,国际上报道的已有21个血清型,但有人认为20型参考菌株670/89不属于RA,故实际上只有20个血清型。随着时间的推移,RA的血清型将越来越趋于多样化,由于血清型之间无交叉免疫保护作用, 相似文献
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鸭传染性浆膜炎是由鸭疫里氏杆菌(Riemerella anatipestiler,RA)引起的一种接触性传染病,主要侵害雏鸭、雏鹅等多种禽类,多发于2~7周龄的雏鸭,呈急性或慢性败血症。鸭疫里氏杆菌血清型众多,已经公开报道的就达25种之多,不同血清型的RA菌株、同一血清型不同源的RA分离菌株,其致病性存在差异,且不同血清型的菌株之间缺乏免疫交叉保护能力。剖检以纤维素性心包炎、肝周炎、气囊炎、脑膜炎等为特征,死亡率为1%~80%,有的甚至高达90%以上。耐过的鸭生长迟缓,增重减慢。由于该病常常导致大批幼鸭发病、死亡以及生长迟缓、饲料报酬显著下降,而且该病难以扑灭,在发病鸭场持续存在,引起不同批次的幼鸭感染发病,因此被认为是造成宁波地区养鸭业经济损失最严重的疫病之一。 相似文献
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鸭传染性浆膜炎是由鸭疫里默氏杆菌(Riemerella anatipestifer,RA)引起的一种接触性传染病,主要侵害1~8周龄的雏鸭。鸭传染性浆膜炎于1932年首次报道于纽约长岛3个鸭场之后,英国、加拿大、挪威、前苏联、澳大利亚、丹麦、德国等国家和地区都相继有报道,并且在野鸭、火鸡、雉鸡、鸡、珍珠鸡、 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
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
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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
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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
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Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
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
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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