Disease of Digestive Tract Flashcards
1
Q
Digestive System
A
- consist of GI tract and accessory structures
- stomach and small intestine have few organisms
- large intestine has 100 billion bacteria per gram feces
2
Q
norma biota
A
- large variety of normal biota
- oral cavity alone; more than 550 known species of microorganisms
- esophagus and stomach much more sparsely populated
- large intestine; billions of microorganisms
- Gm negative and Gm positive bacteria
- Anaerobes and facultative anaerobes
- lactobacillus, Bacteroides, E. coli, Enterobacter, Klebsiella, Proteus
3
Q
Defenses
A
- mucus
- Secretory IgA
- Peristalsis
- fluids with antimicrobial: saliva, stomach fluid, bile
- GALT tissues (gut associated lymph tissue): tonsils, adenoids, lymphoid tissue in the esophagus, Peyer’s patches, appendix
- microbial antagonism
4
Q
Dental Caries
A
more than 300 species on and around the teeth
- ferment sugars and carbohydrates into lactic acid which dissolves away enamel
- form biofilms on teeth
- Streptococcus mutans and other streptococci
- Protein from salvia coats the teeth and the bacteria adhere
- Bacteria produce dextrin’s from sucrose to form dental plaque
- Actinomyces may be part of the flora
5
Q
Periodontitis
A
- initial stage: gingivitis (swelling, loss of normal contour, patches of redness, and increased bleeding of the gingival
- Gingivitis (early)- gums irritated
- plaque forms
- plaque calcifies-calculus
- if gingivitis persists, periodontitis develops
- extension of gingivitis into the periodontal membrane and cementum
- increased the size of pockets between the tooth and the gingival and can cause bone resorption enough to loosen and possible lose the tooth
6
Q
Disease of Lower Digestive System
A
- infection-pathogen multiples in the GI tract
- intoxication- occurs when person ingests a preformed toxin which causes disease symptoms
- dysentery- blood diarrhea
- gastroenteritis- inflammation of the stomach and intestinal mucosa
7
Q
exotoxin
A
-toxin produced and released by bacteria
8
Q
enterotoxin
A
-type of exotoxin that affects the mucosal lining of the gut
9
Q
endotoxin
A
-toxin that is part of the gram negative cell wall
10
Q
infective dose
A
number of organisms needed to cause an infection
11
Q
staphycoccal food poisoning
A
food intoxication
- S. aureus strains that produce enterotoxin (type of exotoxin)
- organisms come from nasal cavities and skin of food handlers
- resistant to heat, high salt, drying and radiation
- associated with temperature abuse of the food
12
Q
Salmonellosis: food infection
A
- Salmonella spp.
- Heat sensitive but many contaminate food after cooking from cutting boards
- 2000 serotypes
- gastroenteritis
- invade the mucosa and multiply
- need to ingest large numbers of cells
- 12-36 hour incubation
- nausea, abdominal pain, cramps, diarrhea
- infants and old are the hardest hit
13
Q
Pusled-field gel electrophoresis
A
- DNA from Salmonella is separated on a gel by running an electric current through gel
- different strains will have different patterns
- can “fingerprint” the DNA from strains
- type of molecular finger-printing
- CDC has national data base called PulseNet
14
Q
Salmonella Outbreaks
A
traced to:
- milk
- peanut butter
- eggs
- poultry
- vegetables:sprouts, cantaloupe
15
Q
Typhoid Fever
A
- Salmonella typhi and other stains
- oral route; water/food
- 2 weeks incubation
- fever, malaise, headache
- microbes don’t multiply in gut but multiply in the phagocytic cells
- Used to have high mortality rate
- chronic carriers
- vaccine, live oral or killed
