大肠杆菌耐药性的研究进展

大肠杆菌是一种常见致病菌,预防困难。近年来的研究表明,大肠杆菌的耐药株不断增多,特别是多重耐药株的大量出现,使兽医临床大肠杆菌病的治疗变得十分困难。大肠杆菌对抗生素的耐药问题是当前国内外研究的热点。对国内外大肠杆菌耐药现状以及产生耐药性机制的研究进展做一综述。     

鸡致病性大肠杆菌耐药性的研究进展

大肠杆菌是一种常见致病菌,近年来,大肠杆菌的耐药株不断增多,特别是多重耐药株的大量出现,使其治疗变得十分困难。本文对鸡致病性大肠杆菌耐药现状以及产生耐药性机制的研究作以综述,以期为进一步研究鸡大肠杆菌病的综合防治提供依据。     

氮磷营养盐条件下大肠杆菌对氯霉素耐药性及机理研究

为探讨氮磷营养盐对环境大肠杆菌(E.coli)耐药性的影响及其机制,本试验通过建立模型生态系统研究氮磷营养盐引发大肠杆菌对氯霉素(CHL)产生耐药表型的影响,并对分离到的耐药菌株和敏感菌株进行cat基因检测.结果显示,添加不同剂量氮磷营养盐可引发大肠杆菌对氯霉素产生耐药性,46株耐氯霉素大肠杆菌cat基因的阳性率为89.13%;16株对氯霉素敏感的大肠杆菌未检出cat基因.结果表明,模拟生态系统中加入氮磷营养盐可引发大肠杆菌对氯霉素产生耐药;氮磷营养盐引发大肠杆菌对氯霉素耐药与cat基因有关.     

中药连翘对耐药大肠杆菌抑制作用的研究

大肠杆菌是临床感染中最常见的病原菌之一,目前国内外一般借助于抗生素治疗大肠杆菌病,效果良好.但随着抗生素的不断应用及不合理用药,导致细菌的耐药问题越来越严重,随着耐药水平的不断提高和耐药谱的不断扩大,多数病原菌对抗生素都可产生多重耐药性,因而给抑制剂的开发带来一定困难.研究发现,有些中药具有一定的抗菌、抗病毒作用,并且中药价格低,不产生耐药性,可以克服抗生素的诸多弊端,可作为新型的多重耐药抑制剂进行开发、研究[1].试验在前人研究的基础上,采用体外培养试验来初步研究中药连翘对耐药大肠杆菌的抑制作用,以期为进一步探讨耐药抑制剂的作用机制提供基础资料.     

大肠杆菌对氟喹诺酮类药物的耐药机制研究现状

大肠杆菌是典型的革兰氏阴性杆菌,其耐药谱广,耐药机制复杂,是国内外耐药性研究较为详细的细菌.大肠杆菌对氟喹诺酮药物的耐药性问题是当前国内外研究的热点.本文就大肠杆菌与氟喹诺酮耐药性有关的gyrA、gyrB、parC、parE点突变;多药外输泵;多重耐药基因;抗性质粒等方面的研究进展作一综述.     

我国猪源和鸡源大肠杆菌抗生素耐药性相关基因研究进展

大肠杆菌作为一种条件致病菌和重要的耐药性指示菌,国内外已有大量猪源、鸡源大肠杆菌耐药性相关基因的研究报道.受动物种属、地域等来源性差异,以及耐药机制、亚型等因素的影响,研究中涉及很多种不同的耐药性相关基因,且检出率也不尽相同.根据耐受抗菌药物种类,对这些基因作用机理及分布情况等方面综述,以期为研究大肠杆菌耐药性产生机制...     

牛源大肠杆菌耐药性研究进展

牛源致病性大肠杆菌是导致牛细菌性疾病的重要病原体之一,抗菌药是治疗及预防牛大肠杆菌病的重要手段,然而在养殖过程中,长期且不合理的使用抗菌药物,导致大肠杆菌耐药问题频发,且耐药性具有通过人与动物的直接接触或借助食物链将耐药基因从动物传播给人类的可能,严重威胁人类健康及公共卫生安全。本文根据近几年国内外关于牛源大肠杆菌耐药性基因的研究报道,对大肠杆菌耐药机制、耐药基因检出率及耐药表型进行综述,以期为大肠杆菌耐药性的研究提供参考。     

鸡大肠杆菌耐药质粒的研究进展

鸡大肠杆菌病是一种常见疾病,在治疗过程中容易产生耐药性,给养鸡业预防和治疗该病带来很大困难,本文就鸡大肠杆菌耐药质粒的研究概况进行综述.     

猪大肠杆菌对抗生素耐药性的研究进展

猪大肠杆菌对抗生素的耐药性日益严重,尤其在我国情况更为突出.本文对猪大肠杆菌的耐药性状况及常见抗生素的耐药机制进行了概述,以期为进一步对猪大肠杆菌病的综合防治研究提供理论依据.     

上海市鸡源大肠杆菌分离鉴定及药敏分析

为了掌握上海市鸡源大肠杆菌耐药情况以及耐药规律,按照常规方法分离培养大肠杆菌,应用HX-21细菌鉴定/药敏分析仪以及API 20E鉴定系统进行了细菌鉴定,采用HX-21细菌鉴定/药敏分析仪测定了大肠杆菌对24种抗菌药的耐药情况,并结合菌株来源对菌株耐药性变化及耐药性产生的相关性进行了较全面统计分析.结果表明,上海地区鸡源大肠杆菌耐药性严重,对阿米卡星、多黏菌素耐药性低,对氨苄西林、四环素、复方新诺明、奈定酸、利福平耐药性高.仔鸡大肠杆菌对氟苯尼考、庆大霉素、氯霉素、氨苄西林耐药性强于雏鸡大肠杆菌.耐药谱复杂,多重耐药性、交叉耐药性严重.     

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.     

中华人民共和国农业部公告 第267号

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。 …