1、第三節(jié)弧菌VIBRIO,種類(lèi) 霍亂弧菌vibrio cholerae 副溶血性弧菌Vibrio parahaemolyticus,學(xué)習(xí)要點(diǎn),1掌握致病物質(zhì)，致病機(jī)理。 2.霍亂糞便的特征 3熟悉形態(tài)、染色、動(dòng)力、培養(yǎng)（耐堿性），防治原則。,一、霍亂弧菌 霍亂cholera 所致霍亂為烈性傳染病，被列為國(guó)境檢疫的傳染病 （一）兩生物型： 古典生物型classical biotype ELTOR生物型：目前主要病原菌 （二）生物學(xué)性狀 1、形態(tài) 新分離菌 弧狀，一條鞭毛， 逗點(diǎn)狀，運(yùn)動(dòng)極活潑， 似“魚(yú)群”穿梭,霍亂弧菌的形態(tài),2、培養(yǎng)特點(diǎn)：耐堿性，在PH8.59.5蛋白胨液體培養(yǎng)基中生長(zhǎng)良好 （三

2、）致病物質(zhì)： 鞭毛、菌毛 粘多糖酶：利于細(xì)菌通過(guò)腸粘液屏障 霍亂腸毒素：（外毒素enterotoxin ） 致病重要物質(zhì),傳染方式,糞-口途徑fecal contamination 107-109弧菌/ml糞便 主要的動(dòng)物傳染源：海產(chǎn)品（貝殼類(lèi)） Ingestion of these without adequate cooking can transmit the disease 我國(guó)生食、半生食所致霍亂占飲食感染的80% 泥鰍、鱔魚(yú)是保存宿主,（四）發(fā)病機(jī)理：,病原菌,腸粘膜上皮細(xì)胞表面繁殖,細(xì)胞內(nèi)cAMP升高,粘多糖酶,腸毒素,空腸至回腸部腺細(xì)胞 分泌大量體液、Na+、K+、cl- 入腸

3、道,霍亂癥狀,水樣腹瀉watery diarrhea(no red blood cells and white blood cell, painless) 嘔吐vomit 排泄“米泔水”樣便“Rice-water” stool 體液平衡失調(diào) 休克shock,The mortality rate without treatment is 40%,“米泔水”樣便“Rice-water” stool,微生物學(xué)檢查與預(yù)防,取米泔水樣糞便或嘔吐物為標(biāo)本 特異性預(yù)防：接種霍亂死疫苗,小結(jié),1、分類(lèi)：古典生物型 ELTor生物型 2、致病物質(zhì)： 菌毛、鞭毛、粘多糖酶 霍亂腸毒素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、生物學(xué)性狀,形態(tài)：輕度“S”型彎曲，一端有4-6條鞭毛 染色：革蘭陰性 培養(yǎng)特性：營(yíng)養(yǎng)要求高，生長(zhǎng)緩慢 抵抗力：對(duì)多種抗生素敏感 羥氨芐青霉素 慶大霉素,HP,二、致病物質(zhì),螺旋體狀，鞭毛：穿過(guò)粘液層 粘蛋白酶 脂酶 降解粘液，破壞粘膜屏障 磷脂酶A2 毛樣蛋白：與胃上皮細(xì)胞受體結(jié)合 抑制蛋白：抑制胃酸分泌 尿素酶：減少ATP合成,小結(jié),一、掌握幽門(mén)螺桿菌致病

6、物質(zhì) 二、熟悉幽門(mén)螺桿菌所致疾病 三、了解幽門(mén)螺桿菌形態(tài)和染色、 培養(yǎng)、抵抗力、微生物學(xué)檢查,與疾病的關(guān)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 胃酸過(guò)多 引起胃潰瘍 生活壓力 生活方式 目前認(rèn)為胃潰瘍與細(xì)菌感染有關(guān) 意味著可能用抗菌素治療胃潰瘍,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,形態(tài)“S”型彎曲,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