霍乱弧菌弧菌VIBRI

1、第三节弧菌VIBRIO,种类 霍乱弧菌vibrio cholerae 副溶血性弧菌Vibrio parahaemolyticus,学习要点,1掌握致病物质，致病机理。 2.霍乱粪便的特征 3熟悉形态、染色、动力、培养（耐碱性），防治原则。,一、霍乱弧菌 霍乱cholera 所致霍乱为烈性传染病，被列为国境检疫的传染病 （一）两生物型： 古典生物型classical biotype ELTOR生物型：目前主要病原菌 （二）生物学性状 1、形态 新分离菌 弧状，一条鞭毛， 逗点状，运动极活泼， 似“鱼群”穿梭,霍乱弧菌的形态,2、培养特点：耐碱性，在PH8.59.5蛋白胨液体培养基中生长良好 （三

2、）致病物质： 鞭毛、菌毛 粘多糖酶：利于细菌通过肠粘液屏障 霍乱肠毒素：（外毒素enterotoxin ） 致病重要物质,传染方式,粪-口途径fecal contamination 107-109弧菌/ml粪便 主要的动物传染源：海产品（贝壳类） Ingestion of these without adequate cooking can transmit the disease 我国生食、半生食所致霍乱占饮食感染的80% 泥鳅、鳝鱼是保存宿主,（四）发病机理：,病原菌,肠粘膜上皮细胞表面繁殖,细胞内cAMP升高,粘多糖酶,肠毒素,空肠至回肠部腺细胞 分泌大量体液、Na+、K+、cl- 入肠

3、道,霍乱症状,水样腹泻watery diarrhea(no red blood cells and white blood cell, painless) 呕吐vomit 排泄“米泔水”样便“Rice-water” stool 体液平衡失调 休克shock,The mortality rate without treatment is 40%,“米泔水”样便“Rice-water” stool,微生物学检查与预防,取米泔水样粪便或呕吐物为标本 特异性预防：接种霍乱死疫苗,小结,1、分类：古典生物型 ELTor生物型 2、致病物质： 菌毛、鞭毛、粘多糖酶 霍乱肠毒素enterotoxin,Sum

4、mery from WHO,Cholera is an acute intestinal infection caused by ingestion of food or water contaminated with the bacterium Vibrio cholerae. It has a short incubation period, from less than one day to five days, and produces an enterotoxin that causes a copious, painless, watery diarrhea that can qu

5、ickly lead to severe dehydration and death if treatment is not promptly given. Vomiting also occurs in most patients,一、生物学性状,形态：轻度“S”型弯曲，一端有4-6条鞭毛 染色：革兰阴性 培养特性：营养要求高，生长缓慢 抵抗力：对多种抗生素敏感 羟氨苄青霉素 庆大霉素,HP,二、致病物质,螺旋体状，鞭毛：穿过粘液层 粘蛋白酶 脂酶 降解粘液，破坏粘膜屏障 磷脂酶A2 毛样蛋白：与胃上皮细胞受体结合 抑制蛋白：抑制胃酸分泌 尿素酶：减少ATP合成,小结,一、掌握幽门螺杆菌致病

6、物质 二、熟悉幽门螺杆菌所致疾病 三、了解幽门螺杆菌形态和染色、 培养、抵抗力、微生物学检查,与疾病的关系,Before 1982, when this bacterium was discovered, spicy food(辛辣）, acid, stress and lifestyle were considered the major causes of ulcers. Since it is now known that most ulcers are caused by an infection with H. pylori, they can be cured with appro

7、priate antibiotics.,1982年前 辛辣食物 胃酸过多 引起胃溃疡 生活压力 生活方式 目前认为胃溃疡与细菌感染有关 意味着可能用抗菌素治疗胃溃疡,How common is H. pylori,About two-thirds of the worlds population is infected with H. pylori. In the United States, H. pylori is found more often in older adults, African Americans, Hispanics （西班牙人）and lower socioecon

8、omic groups.,HP感染百分比,2/3世界人口,形态“S”型弯曲,What are the symptoms of ulcers,The most common ulcer symptom is gnawing or burning pain in the abdomen between the breastbone and the navel. Commonly, the pain occurs when the stomach is empty between meals and in the early morning hours but it also can occur a

9、t other times of the day. It may last from minutes to hours and may be relieved by eating or taking antacids.,How do people get infected with H. pylori?,It is not known how the bacteria get into the body or why some people with H. pylori become ill while others do not. The bacteria most likely sprea

10、d from person to person through the fecal-oral route (when infected fecal matter comes in contact with hands, food or water) or the oral-oral route (when infected saliva or vomit comes in contact with hands, food or water).,How is the infection diagnosed?,Blood tests can determine if a person has be

11、en infected by measuring specific H. pylori antibodies. A breath test can determine if H. pylori is in the patients stomach. In this test, the patient is given a harmless substance urea （尿素）with carbon to drink. H. pylori breaks down this urea, and the carbon is absorbed into the bloodstream and lun

12、gs and then exhaled in the breath.,Endoscopy, biopsy specimens (tissue samples) of the stomach lining can be obtained. Several tests can be performed on these tissue samples to determine if the patient is infected with H. pylori.,gold standard for detecting a bacterium： no more than 60 - 90% sensitive, being 100% specific Wright-Giemsa and Brown-Hopps stains sensitivity at 80 - 95% with 100% specificity,CULTURE,HISTOLOGY,TREATMENT,Antibiotics are the new