奶牛乳房炎化脓隐秘杆菌的分离鉴定及生物学特性研究

发布时间：2018-03-25 04:36

本文选题：奶牛乳房炎　切入点：化脓隐秘杆菌　出处：《西北农林科技大学》2015年硕士论文

【摘要】：陕西咸阳某奶牛场一奶牛出现食欲不振,以乳汁分泌量减少,乳房肿胀为主要特征的疾病,初步鉴定为奶牛临床型乳房炎。为了控制此病的蔓延,通过对致病菌分离纯化、形态学观察、生化试验及体外药物敏感性试验,鉴定出一株致病菌命名为HNYM。试验结果如下:1、从患病奶牛乳汁中分离出一株细菌,命名为HNYM株。分离纯化的菌株在血平板上生长良好,有β溶血现象。菌落微小呈针尖状,菌落扁平、边缘整齐、白色、不透明、干燥菌落。革兰染色镜检为阳性长杆菌。2、将细菌的纯培养物进行糖发酵试验,分离菌能发酵葡萄糖、麦芽糖、果糖、乳糖、D-果糖、蕈糖、鼠李糖、D-木糖、树胶醛糖、菊糖产酸,M.R、V-P试验、接触酶试验呈阴性,疑是化脓隐秘杆菌。对消毒剂和β-内酰胺类抗生素较为敏感,对磺胺类药物具有抗性。3、16S rRNA序列与化脓隐秘杆菌属细菌的同源性最高,在92%~99%之间。遗传进化树分析结果表明,HNYM株与化脓隐秘杆菌属在同一大类,最终诊断该奶牛为化脓隐秘杆菌感染。4、小白鼠腹腔注射不同体积菌液,剖检发现心脏、肝脏、肺脏等组织均有明显病变,肌肉注射不同体积菌液,腿部肌肉化脓坏死,后肢瘫痪,对照组健康存活。上述试验结果表面,化脓隐秘杆菌HNYM株对小鼠有致病性,外毒素是其主要致病因子。综上所述,本研究所分离HNYM菌株鉴定为化脓隐秘杆菌,耐药性不强、致病性较强。
[Abstract]:Shaanxi Xianyang a dairy cows appeared to a loss of appetite, decreased milk secretion, breast swelling as the main characteristics of the disease, identification of clinical mastitis. In order to control the spread of the disease, by observing the morphology of bacteria, isolation and purification, biochemical test and in vitro drug sensitivity test, identification of a pathogen named HNYM. test results are as follows: 1, one bacterial strain was isolated from diseased cow milk, named HNYM strain. The separation and purification of the strains grew well on blood agar, beta hemolytic phenomena. Small colonies showed a needle like colony, flat, the edge is neat, white, opaque, dry colonies. Gram staining for coli.2 positive long, pure cultures of bacteria by sugar fermentation test, bacteria can ferment glucose, maltose, fructose, lactose, fructose D-, mushroom sugar, rhamnose, arabinose, xylose D-, inulin acid, M.R, V-P Test, catalase test was negative, the suspect is more sensitive to Arcanobacterium pyogenes. Disinfectants and beta lactam antibiotic resistant.3,16S rRNA sequence and Arcanobacterium pyogenes bacteria homology of sulfa drugs in 92%~99%. Phylogenetic analysis showed that HNYM strain and Arcanobacterium pyogenes in the same class, the final diagnosis of the cows Arcanobacterium pyogenes infection.4 mice, intraperitoneal injection of different volume of bacteria, autopsy found that the heart, liver, lung lesions were significantly different volume, intramuscular injection of bacteria liquid, leg muscle tissue necrosis, hind limb paralysis, healthy control group. The survival test results the surface of the Arcanobacterium pyogenes HNYM strain of mice are pathogenic toxin is the main pathogenic factor. In summary, this study HNYM isolated strain was identified as Corynebacterium pyogenes, drug resistance is not strong, pathogenicity is Strong.

【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S858.23

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