共查询到20条相似文献，搜索用时 190 毫秒
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氨基糖苷类由氨基环醇和氨基糖以苷键相连接而形成的碱性抗生素。这类抗生素包括，链霉素、新霉素、卡那霉素等，他们的共同特点是水溶性好，性质稳定，抗菌谱较广，对葡萄球菌属、需氧革兰氏阴性杆菌及分支杆菌属（结核杆菌）均有抗菌活性，主要抑制细菌合成蛋白质。 相似文献
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为了探究枯草芽胞杆菌对哺乳仔猪鼻腔中微生物多样性及其功能的影响，选用1株来源于猪鼻腔的枯草芽胞杆菌NS15对哺乳期仔猪进行喷鼻试验，于喷鼻后第7天采集鼻腔拭子，随后利用16S rRNA基因高通量测序技术检测分析鼻腔拭子样本菌群结构并进行功能预测。结果显示：猪鼻腔的优势菌门为厚壁菌门(Firmicutes)、放线菌门(Actinobacteria)、变形菌门(Proteobacteria)和拟杆菌门(Bacteroidetes)。喷鼻后不影响优势菌门的组成，但是各菌门的丰度发生变化，如厚壁菌门和放线菌门的丰度增加，其中厚壁菌门中的乳杆菌属(Lactobacillus)和放线菌门中的罗氏菌属(Rothia)等有益菌属丰度增加；而变形菌门和拟杆菌门等有害菌门的丰度下降，包括变形菌门中的不动杆菌属(Acinetobacter)、嗜麦芽窄食单胞菌属(Stenotrophomonas)和鲍特菌属(Bordetella)以及拟杆菌门中的黄杆菌属(Flavobacterium)等有害菌属丰度下降。进一步Tax4Fun功能预测结果显示，喷鼻枯草芽胞杆菌NS15后，猪鼻腔中能量、氨基酸和脂类等代谢通路显著... 相似文献
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不同品种猪肠道拟杆菌属-普雷沃氏菌属群实时荧光定量分析 总被引：3，自引：0，他引：3
对猪肠道30种细菌的16SrDNA序列进行比对分析,设计拟杆菌属-普雷沃氏菌属荧光定量的特异引物。以多形拟杆菌菌株(CDC1404-A)基因组的DNA为模板,以常规PCR引物扩增16SrDNA靶片断,将PCR产物纯化后作为DNA标准品,将梯度稀释的标准品作模板,建立定量标准曲线。以TaqMan探针建立25μL反应体系,对不同浓度的多形拟杆菌DNA样品进行检测,并以乳酸杆菌、大肠杆菌和双歧杆菌的基因组DNA模板作阴性对照,验证此方法检测拟杆菌属-普雷沃氏菌属的特异性。结果表明:设计的荧光定量引物和探针,仅对拟杆菌和普雷沃氏菌有很强的特异性,该方法的灵敏度可3.73个/μL的基因组DNA。将PCR方法用于5月龄长白和太湖猪回肠内容物检测,其拟杆菌属-普雷沃氏菌属的检测结果呈阳性,每克回肠内容物拟杆菌属-普雷沃氏菌属数量的拷贝数对数值太湖猪比长白猪高38.5%(P<0.10),而且发现拟杆菌属-普雷沃氏菌属数量与背膘厚度、脂肪率之间有正相关关系。 相似文献
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乳酸菌是我国最早公布的2种可直接使用的饲料级微生物添加剂菌种之一，是一类革兰阳性杆菌或球菌，触酶阴性，不形成芽孢，不运动，兼性厌氧，对葡萄糖发酵能产生超过50％乳酸的异养型细菌的总称。包括乳杆菌属（Lactobacillus）、链球菌属（streptococcus）、明串珠菌属（Leuconosmc）和片球菌属（Pediococmas）。近年来随着细菌分类的发展，乳酸菌分类体系已由4属增至12属或更多属，但这只不过是上4属乳酸菌属内的再分或属与属之间再形成新属，并没有超出乳酸菌的定义范围。 相似文献
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乳酸菌是动物肠道内重要的生理性菌群,本研究以内蒙古锡林郭勒盟牧区自然放养的牛、马、山羊和绵羊为研究对象,对其肠道中的乳酸菌进行分离和16S rRNA鉴定,并对38株罗伊氏乳杆菌进行耐酸性、模拟胃肠液转运和胆盐耐受性试验。乳酸菌分离鉴定结果显示共分离到乳酸菌纯培养物96株,包括双歧杆菌属、肠球菌属、乳杆菌属和链球菌属四个菌属,其中乳杆菌属数量最多,为所有分离株的82.29%;乳杆菌属中罗伊氏乳杆菌所占比例最大,为48.10%。益生特性筛选试验结果显示菌株IMAU10240、IMAU10230和IMAU10256具有良好的耐酸、耐胃肠液和胆盐特性,可作为潜在益生菌进行进一步的益生功能研究。 相似文献
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任文义李娅楠杨双鸣张力莉徐晓锋 《饲料研究》2023,(8):78-83
试验旨在研究地衣芽孢杆菌与植物乳杆菌复合微贮稻草发酵对稻草营养成分的影响及可能机制。试验采用完全随机设计，随机分为5组，每组6个重复。对照组稻草不添加菌剂进行微贮，植物乳杆菌组、复合菌组Ⅰ、复合菌组Ⅱ和复合菌组Ⅲ微贮稻草的地衣芽孢杆菌添加量分别为0、8×105、1×106、1.2×106 CFU/g DM，植物乳杆菌添加量均为5×106 CFU/g DM。试验期30 d。结果显示，发酵第30 d，复合菌组Ⅰ、复合菌组Ⅱ和复合菌组Ⅲ稻草微贮的pH值均显著低于对照组（P<0.05）。复合菌组Ⅲ的隶属函数平均值结果综合表现最优。发酵7 d时稻草微贮细菌群落的丰富度和多样性最高。在门水平上，厚壁菌门相对丰度随着发酵时间的增加而增加；在属水平上，乳杆菌属丰度呈先增加后减少趋势，第7 d时最高。溶酶体、鞘脂类代谢、其他多糖降解、糖胺聚糖降解、磷酸盐和磷酸盐代谢等途径在稻草发酵过程具有明显差异。研究表明，植物乳杆菌复合地衣芽孢杆菌微贮稻草发酵优于单独添加植物乳杆菌。 相似文献
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在目前的细菌分类中，拟杆菌门（Bacteroidetes）黄杆菌科（Flavobacteriaceae）的里默杆菌属（Riemerella）由鸭疫里默杆菌（Riemerella anatipestifer ）和鸽里默杆菌（Riemerella columbina ）两个种组成。有研究者分离鉴定到家鸽源表型特征类似于黄杆菌科里默杆菌属成员的菌株，并被建议命名为鸽咽喉里默杆菌新种（Riemerella columbipharyngis sp．nov）。论文对里默杆菌属的分类进展及对里默杆菌属、鸭疫里默杆菌、鸽里默杆菌种的修订描述和鸽咽喉里默杆菌新种的描述等进行了综述。 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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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
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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