惠州地区鸡白痢和鸡伤寒沙门菌病血清学调查

为了解惠州地区鸡白痢和鸡伤寒沙门菌病的发生与流行现状,为本病的防治提供依据,采用平板凝集试验对惠州地区的部分禽群进行鸡白痢和鸡伤寒沙门菌病血清学调查。结果显示,惠州地区鸡白痢和鸡伤寒沙门菌病抗体阳性率为8.30%,惠州地区不同养殖模式鸡群、不同县(区)(仲恺区除外)鸡群、不同日龄鸡群、不同用途鸡群,种禽场不同性别禽群均有不同程度感染鸡白痢和鸡伤寒沙门菌病,说明惠州地区的鸡群受鸡白痢和鸡伤寒沙门菌病感染的情况普遍存在,相关部门应该切实加强对该病的防制与净化工作。     

种禽场疫病监测与净化

正为掌握种禽场主要垂直传播性动物疫病流行状况,为制定种禽疫病净化政策提供科学依据,农业部自2011年起对全国祖代及以上种鸡场和4个国家级家禽基因库开展禽白血病、网状内皮组织增殖症、鸡白痢等主要垂直传播性疫病监测。迄今为止,种禽场疫病监测已持续5年,充分了解了种禽场垂直传播疫病的感染情况。自此基础上,中国动物疫病预防控制中心对祖代以上种鸡场疫病净化现状持续跟踪,深入了解种禽场疫病净化存在的问题和面临的困境,促进疫病净化工作深入开展。     

黄羽肉种鸡场死胚中鸡白痢沙门菌的分离鉴定及耐药性分析

为了解广东某黄羽肉种鸡场鸡白痢沙门菌的感染及耐药情况,随机采集该场孵化至21日胚龄时的117个死亡胚进行鸡白痢沙门菌分离,通过生化鉴定、PCR、血清分型及rfbS基因序列测定等鉴定鸡白痢沙门菌分离株,并采用琼脂稀释法测定分离株对16种抗菌药物的最小抑菌浓度(MIC)。结果显示:共分离鉴定出18株鸡白痢沙门菌,分离率为15.38%;18个鸡白痢沙门菌分离株对头孢噻肟、头孢吡肟、亚胺培南、多黏菌素B、庆大霉素、阿米卡星、氟苯尼考、链霉素均敏感,而对磺胺异吡恶唑(100%)、萘啶酸(72.2%)、氨苄西林(55.6%)、四环素(44.4%)耐药率较高,且分离株均有多重耐药性。研究表明该黄羽肉种鸡场已受到鸡白痢沙门菌感染的困扰,有必要尽快启动鸡白痢沙门菌防控与净化。     

威海市种禽场主要疫病监测情况的分析

为了掌握威海市种禽场主要疫病免疫抗体水平及病毒感染情况,2015-2017年对威海市全部25个种禽场分别进行了新城疫、禽白血病、鸡白痢疫病监测,监测结果显示全市新城疫免疫抗体水平均在90%以上,整体免疫效果良好,暴露风险较低;新城疫病原阳性率0.28%,禽白血病阳性率1.02%,鸡白痢感染抗体阳性率为0.52%。群体健康状况良好,禽白血病和鸡白痢接近国家净化标准。     

鸡白痢与鸡伤寒沙门菌双重PCR方法的建立和初步应用

分析不同血清型/生物型沙门菌全基因组序列筛选出鸡白痢和鸡伤寒沙门菌特异性基因组序列,设计两对引物,建立双重PCR方法鉴别检测鸡白痢和鸡伤寒沙门菌不同生物型,并进行初步的临床应用。双重PCR方法结果显示,鸡白痢沙门菌显示417 bp条带,鸡伤寒沙门菌显示417 bp和636 bp两个条带,而阴性对照未出现条带,与预期设计相符。双重PCR体系对56株不同血清型沙门菌鉴定结果与细菌学分离的血清型鉴定结果完全一致,说明本试验建立的双重PCR体系特异性良好,应用上述方法检测鸡场疑似20份临床样本,结果发现8株鸡白痢沙门菌阳性,1株鸡伤寒沙门菌阳性。上述结果表明,已建立双重PCR方法特异性检测鸡白痢和鸡伤寒沙门菌。本试验为鸡白痢和鸡伤寒不同生物型沙门菌的检测提供了一种简洁、敏感、特异的新方法。     

血清和全血平板凝集方法检测鸡白痢抗体的差异比较

正鸡白痢沙门菌可引起雏鸡大批量死亡,产蛋鸡产蛋率下降,成年鸡多呈隐性感染,可长期带毒和排毒。鸡白痢沙门氏菌为细胞内寄生菌,利用药物治疗只能临床治愈而不能根除,且药物预防和治疗容易产生耐药性,给家禽养殖业带来严重的经济损失[1],被中国农业部列为二类动物疫病。《国家中长期动物疫病防治规划(2012-2020)》中明确要求到2020年全国所有种鸡场沙门氏菌病达到净化标准。平板凝集试验以其方便、快速、实用等特点成为国内外鸡白痢抗体检测最常用的诊断方     

鸡白痢/禽伤寒沙门菌抗体检测试剂的比较与评估

对市面上现有鸡白痢/禽伤寒沙门菌抗体平板凝集检测试剂及其不同批次,微量凝集检测试剂和ELISA共4种检测试剂进行比较与评估。用4种试剂以及试剂A的不同批次检测来自11个种鸡场的1 650份血清,计算不同试剂检测种鸡场的抗体阳性率,2种试剂之间的阳性符合率、阴性符合率和总符合率,并以Kappa检验判断不同检测方法及其试剂之间的一致性程度。平板凝集试剂A的不同批次间以及平板凝集试剂A和B之间具有高度一致性(Kappa系数=0.714~0.746),但阳性符合率不足80%。平板凝集试剂A、微量凝集试剂C、ELISA试剂D之间仅具有中度或弱一致性(Kappa系数=0.392~0.542)。不同鸡白痢/禽伤寒沙门菌抗体检测试剂间存在差异,平板凝集试剂不同批次间也存在差异,提示试剂生产厂家应加强质量控制,同时研发敏感性、特异性、稳定性更好的替代试剂,而种鸡场在进行抗体监测时应固定使用1种检测试剂,避免影响检测结果的准确性和连续性。     

竹丝鸡鸡白痢沙门菌的分离鉴定与药敏试验

为查找广东某鸡场竹丝鸡雏鸡发病原因,对疑似鸡白痢沙门菌病残鸡进行细菌分离培养、聚合酶链式反应(PCR)鉴定及药敏试验。结果显示:该鸡场共分离获得2株鸡白痢沙门菌(S1、S2),鸡白痢沙门菌是鸡场此次疫病的主要病原;头孢他啶、头孢曲松、阿米卡星、卡那霉素、氟苯尼考、盐酸四环素、甲氧苄啶等抗菌药为2株分离株的首选药物,临床治疗建议避免使用阿莫西林、氨苄西林、链霉素。试验表明,对鸡白痢沙门菌的治疗应重视多重耐药性问题,通过药敏试验选择高敏药物指导临床合理用药。     

祖代种鸡场主要疫病监测与净化对策

为掌握祖代种鸡场主要疫病流行状况,提供制定种鸡疫病净化政策的科学依据,中国动物疫病预防控制中心对祖代以上(含曾祖代、原种)种鸡场开展了禽流感、禽白血病和鸡白痢等疫病的监测。通过明确监测病种、监测范围、监测数量和监测方法,经过持续5年的监测,摸清了我国祖代以上种鸡场禽流感和垂直传播疫病的感染情况,推动种鸡场开展禽流感和垂直传播疫病的监测净化。监测结果显示:当前我国祖代种鸡场禽流感抗体免疫合格率在95%以上。禽白血病病毒(ALV)p27抗原和ALV-J亚群抗体的个体阳性率在2%以下,ALV-A/B亚群抗体除2013和2014年较高之外,其他年份个体阳性率在2%左右。部分祖代种鸡场实现了禽白血病的净化,获得了净化示范场的认证。祖代蛋种鸡场鸡白痢抗体阳性率2011—2014年逐年下降,并一直保持较低水平(低于1%),但2015年有升高的趋势。在此基础上,对祖代种鸡场疫病净化状况持续跟踪,深入了解种鸡场疫病净化的动力及存在问题,提出对策建议,以期促进种源净化工作的深入开展。     

禽沙门菌分离鉴定方法的建立与优化

本研究旨在建立和优化禽沙门菌分离鉴定的方法。选择山东省某地方品种鸡疑似发生沙门菌病的未出壳死胚样品24份,通过4组不同的培养基组合比较沙门菌的分离情况,选择沙门菌通用引物两对和鸡白痢特异性引物一对进行分离株的PCR检测,比较其特异性,然后进行血清分型和MLST分型,确定沙门菌类型并研究其相关性。结果表明,该批样品中TTB比SC增菌效果好,XLD和XLT4选择培养基对沙门菌分离效果相同,最终通过PCR方法鉴定出沙门菌阳性率为58.3%;发现两对通用引物特异性一致,表明可任选一对引物进行PCR鉴定;用鸡白痢沙门菌特异性引物完成的PCR鉴定结果显示,14株沙门菌中有7株为鸡白痢沙门菌;血清型鉴定结果表明,14株沙门菌中有7株鸡白痢沙门菌、7株肠炎沙门菌,共两种血清型;MLST分子分型结果表明,14株沙门菌分为3个ST型,分别是7株ST11、3株ST92和4株ST2151,其中ST11为肠炎沙门菌,ST92和ST2151为鸡白痢沙门菌;本研究表明,疑似沙门菌感染样品经BPW和TTB增菌、XLD或XLT4选择培养基分离培养,最后通过PCR方法可准确完成沙门菌的分离鉴定;同时,应用该方法可完成对鸡白痢沙门菌的鉴定,并与血清分型和MLST分子分型结果一致。     

商会自治的基石——商会自治规范研究

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。     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

猪毛色遗传的研究进展

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。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

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.     

不同样本商品蜂蜜中硒含量的测定

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。     

乳酸杆菌益生作用机制的研究进展

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。     

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.     

Mechanism of Action of Probiotic Function of Lactobacilli

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.     

Evaluation of serum concentrations of biomarkers of skeletal metabolism and results of radiography as indicators of severity of osteochondrosis in foals

OBJECTIVE: To determine whether serum concentrations of biomarkers of skeletal metabolism can, in conjunction with radiographic evaluation, indicate severity of osteochondrosis in developing horses. ANIMALS: 43 Dutch Warmblood foals with varying severity of osteochondrosis. PROCEDURE: 24 foals were monitored for 5 months and 19 foals were monitored for 11 months. Monthly radiographs of femoropatellar-femorotibial and tibio-tarsal joints were graded for osteochondral abnormalities. Serial blood samples were assayed for 8 cartilage and bone biomarkers. At the end of the monitoring period, foals were examined for macroscopic osteochondrosis lesions. RESULTS: Temporal relationships were evident between certain serum biomarkers and osteochondrosis severity in foals during their first year. Biomarkers of collagen degradation (collagenase-generated neoepitopes of type-II collagen fragments, type-I and -II collagen fragments [COL2-3/4C(short)], and cross-linked telopeptide fragments of type-I collagen) and bone mineralization (osteocalcin) were positive indicators of osteochondrosis severity at 5 months of age. In foals with lesions at 11 months of age, osteochondrosis severity correlated negatively with COL2-3/4C(short) and osteocalcin and positively with C-propeptide of type-II procollagen (CPII), a collagen synthesis marker. Radiographic grading of osteochondrosis lesions significantly correlated with macroscopic osteochondrosis severity score at both ages and was strongest when combined with osteocalcin at 5 months and CPII at 11 months. CONCLUSIONS AND CLINICAL RELEVANCE: The ability of serum biomarkers to indicate osteochondrosis severity appears to depend on stage of disease and is strengthened with radiography. In older foals with more permanent lesions, osteochondrosis severity is significantly related to biomarker concentrations of decreased bone formation and increased cartilage synthesis.