支原体,衣原体,立克次体

支原体,衣原体,立克次体

第19章 支原体、衣原体、立克次体

一、教学大纲要求

(1)掌握肺炎支原体和解脲脲原体的生物学特性和微生物学检验。

(2)掌握衣原体的生活周期，掌握沙眼衣原体的微生物学特性和微生物学检验，熟悉衣原体所致疾 病。

(3)掌握立克次体的生物学特性、所致疾病和微生物学检验。

二、教材内容精要

(一)支原体

支原体(Mycoplasma)是一群介于细菌与病毒之间，能在人工培养基中生长繁殖的最小的原核细胞型微生物，支原体没有细胞壁，形态上呈高度多形性，可通过滤菌器。支原体因其缺乏细胞壁归属于柔膜体纲的支原体目。下分三个科:支原体科生长时需从外界环境摄取胆固醇;无胆甾原体科生长时不需外源性胆固醇;螺旋原体科虽生长需要胆固醇，其特点是生长到一定阶段呈螺旋形。支原体科中又分支原体和脲原体二个属。支原体在自然界中分布十分广泛，对人致病的主要是肺炎支原体(Mycopasma pneumoniae，,MP)、解脲脲原体(U.urealyticum)。

1(肺炎支原体

(1)生物学特性

1)形态与染色 肺炎支原体没有细胞壁，仅有细胞膜，呈高度多形性，常见形态为球形、杆形及长丝形，有时可见分枝与星状体。革兰染色阴性，但不易着色，常用姬姆萨染色，呈淡紫色。

2)培养特性 对低渗透压敏感，营养要求高于一般细菌，需加入20%马或小牛血清，多数支原体还需添加新鲜酵母浸液、组织液等。支原体繁殖较慢，在固体培养基上35?培养2,3d，菌落中央的核心部分较厚、向下长入培养基，周边由透明颗粒组成的薄薄的一层贴在琼脂表面，呈油煎蛋菌落。

3)生化反应 肺炎支原体可根据是否能利用葡萄糖、水解精氨酸来与其它致病支原体进行鉴别。

4)抗原结构 支原体的抗原性主要来自细胞膜，胞膜外层蛋白质是支原体的主要型特异性抗原，其抗原性常用生长抑制试验(growth inhibition test,GIT)与代谢抑制试验(metabolism inhibition test，MIT)鉴定。GIT是将吸有型特异性抗血清的滤纸片置于接种有支原体的固体培养基上，经孵育出现同型血清抑制该型支原体生长的现象。MIT是将支原体接种在含有抗血清的葡萄糖(酚红)培养基中，若抗体与支原体型相对应，则抑制该支原体分解葡萄糖，酚红不变色。此两种方法可将支原体分成若干血清型。

5)抵抗力 4?放置不超过3天，56?很快灭活。对热、干燥非常敏感，冻干能长期保存。因支原体无细胞壁，对青霉素、头胞菌素等作用于细胞壁的抗生素不敏感，对脂溶剂、去垢剂和石炭酸、甲醛等常用消毒剂敏感。

(2)临床意义

comply with the corresponding requirements of materials and

manufacturing standards. (4) all pipes, pipe fittings, valves, welding

material must be carried out according to specifications, such as Visual

inspection, after passing the qualifying marks; required strength and

tightness of valves, seals after qualifying, required testing and

adjusting the opening pressure of the relief valve, when they debug,

seals; records and safety valve fill valve test debug logging. Stainless

steel pipe and components shall not be in contact with carbon steel

during storage. (5) building materials, such as sand, stones and other submission submitted in a timely manner, and keep the test report. (6)

all materials are neatly stacked, by category, and clearly identified.

1.2 high pressure pipeline construction 1.2.1 prefabricated pipe (1)

high pressure high pressure pipes should be tested before the pipe

prefabrication, magnetic study after passing inspection, after passing

the magnetic exploration, precast. (2) high-pressure pipeline isometric,

factory prefabricated, and leaving the closed mouth, spot welding. (3)

after the high pressure piping prefabrication, require heat treatment

heat treatment should be carried out promptly. (4) after the high

pressure piping prefabrication should be in time for the piping piping

on number and order number on the same line marking. (5) the completion

of prefabricated sections, inside should be cleaned and should be

promptly closed nozzle. 1.2.2 construction before the conditions of (1)

started reporting approved by the departments concerned or under the

license file. (2) drawings and technical information relating to the

range, and after drawing and design intentions. (3) with respect to

pipeline construction is completed and the a and b have checked, "three

connections and one leveling" construction requirements have been met,

and pipe connection device is looking for

肺炎支原体是非典型肺炎的病原体，主要侵犯呼吸系统。肺炎支原体黏附于黏膜上皮细胞的受体上，吸取宿主细胞的养料生长繁殖，同时释放有毒代谢产物如过氧化氢、核酸酶等使细胞受损。主要通过呼吸道传播，青少年易感，冬秋季较多见，引起间质性肺炎和急性支气管炎，占肺炎发病率的15%~20%，病理变化以间质性肺炎为主。 (3)微生物检验

1)检验程序

标本

分离培养 直接镜检 PCR查DNA

(含血清和酵母浸膏培养基)

37?、5% CO 2

1,2周

典型的菌落

鉴定

革兰染色不着色 生化反应 血清学试验

电镜观察无细胞壁

图 肺炎支原体的检验程序

2)标本采集 一般可取病人痰、咽拭子、鼻咽洗液、支气管分泌物等。因肺炎支原体有粘附细胞的作用，以拭子标本为好。支原体对热和干燥敏感，取材后应立即接种或置转运培养基中(蔗糖磷酸盐缓冲液)，4?能保存72h，-70?或液氮能长期保存。

3)检验方法

显微镜检查 革兰染色不易着色，电子显微镜观察无细胞壁，易与细菌鉴别。

分离培养 常用的培养基以牛心消化液为基础另加20%小牛血清及新鲜酵母浸液制成的液体或固体培养基。在含5%CO大气环境下培养，初分离时，一般10d左右长出菌落，呈致密圆形，常不出现油煎2

蛋状，需经数次传代后，菌落开始典型。肺炎支原体的分离阳性率不高，对临床快速诊断意义不大，但对流行病学调查有重要意义。

4)鉴别要点 iping prefabrication, require heat treatment heat treatment should

be carrpressure pipeline isometric, factory prefabricated, and leaving

the closed mouth, spot welding. (3) after the high pressure p-fter

passing the magnetic exploration, precast. (2) highion, ae (1) high

pressure high pressure pipes should be tested before the pipe

prefabrication, magnetic study after passing inspectials are neatly

stacked, by category, and clearly identified. 1.2 high pressure pipeline

construction 1.2.1 prefabricated pipmateruilding materials, such as sand,

stones and other submission submitted in a timely manner, and keep the

test report. (6) all valve test debug logging. Stainless steel pipe and

components shall not be in contact with carbon steel during storage. (5)

b e filling, required testing and adjusting the opening pressure of the

relief valve, when they debug, seals; records and safety valvsuch as

Visual inspection, after passing the qualifying marks; required strength