医学微生物学英文教学课件：9 vibrio

1、Chapter 9VibrioVibrio is curved, G- short bacilli with a polar flagellum. Vibrio bacteria distribute widely in nature, especially in freshwater and sea.Section 1. Vibrio choleraeV. cholerae cause cholera (an outbreak infectious disease)I biological propertiesG-, short curved rods, single polar flage

2、llum, pili2. facultative aerobe, 1837 grow in high pH (8.8 9.0) medium3. antigenic structure O Ag, heat stable, group specificity 155 serogroup O1 O139 H Ag, heat labile, non- specificity classical biotype El Tor biotypeI biological properties4.resistant sensitive to acid (gastric acid, 4min) heat d

3、ry antibiotic I biological propertiesII Pathogenicity1. Pathogenic factor(1) invasiveness flagellum - help bacteria to penetrate enteric mucous layer, to approach epithelial cells of intestinal wall pili - colonized to small intestine(2) Cholera enterotoxin (similar to LT) the strongest lapactic tox

4、in*B subunit (five) bound unit, attaches to the receptor (GM1) on the epithelial cells of small intestine*A subunit (A1, A2) active unit, enters the cells, stimulates adenylate cyclase cAMP II Pathogenicity 2.Disease - cholera Organisms oral route (contaminated water, food) stomach (gastric acid) at

5、tach to the small intestine epithelial cells (non-penetration) multiplication cholera toxin adenylate cyclase cAMP concentration secreting effect severe diarrhea (rice-water stools ) *patient may lose as much as 1L liquid / hr*rapid dehydration and hypovolaemic shock death in 12-24 hour*rice-water s

6、tools - mucosa, epithelial cells, large number of vibrio*recover: gallbladderII Pathogenicity1. Nonspecific immunity: gastric acid2. Specific immunity: SIgA3. Persistent immunity to the same serotypeII Immunity1.Rapid diagnosis rice-water stools - hanging-drop observation; gram stain2.Isolation basi

7、c peptone water, 37 3.Identification III Microbiologic Examination1.Vaccine *Inoculation of dead bacteria-vaccine *Live attenuated oral vaccine - against O1, O139 *Genetic engineering vaccineIV Prevention & Treatment2. give the life-saving replacement of fluid and electrolytes sodium chloride 3.5 goral/intravenous potassium chloride 1.5 g rehydration sodium citrate 2.9 g solution glucose 20.0 g c