Study sets, textbooks, questions
Upgrade to remove ads
Week 14 Microbiology Gastrointestinal Pathogens
Highlighted Orange Objectives
Terms in this set (23)
What are enteric bacteria?
bacteria that colonize or invade the intestine.
What is the most common morphology and Gram stain of enteric bacteria?
Describe the role of streptococcus mutant in dental caries.
Ferments sugars and produces lactic acid, which accumulates in plaque and degrades enamel.
Name the causative agent and process of disease associated with bacterial endocarditis.
Process of disease: Bacteria colonize damaged or improperly working heart valves, causing inflammation and blood clots in the blood stream.
Why are patients with heart valve issues susceptible to endocarditis?
Because these types of bacteria colonize damaged or improperly working heart valves.
Why is bacterial endocarditis associated with dental surgery?
Because during teeth extractions, the bacteria in the teeth can lead to open blood vessels in the sockets leading the bacteria to enter the blood system.
How does prophylactic antibiotics prevent bacterial endocarditis?
These help prevent infections before a surgery.
Describe the morphology of helicobacter pylori
gram negative vibrio
What are some unique characteristics of Heliobacter pylori that allow it to survive in low pH of the stomach?
secrets a urea buffer to make its environment more basic.
What diseases is H. pylori associated with?
10-20% of infections cause peptic ulcer disease(stomach ulcers)
1-2% of infections cause stomach cancer
What is the prevalence of H. pylori?
More than 50% of the world are infected, and its most commonly in developing worlds (poor sanitation, lower antibiotic use)
Which two age groups is bacterial enteritis particularly deadly for?
Infants and elderly.
Explain how a person gets sick with enterotoxin food poisoning bacteria, given the bacteria can cause symptoms, but do not directly infect the host.
They cause disease, NOT bacterial infection. They are exotoxins that affect the intestine. Hence, the word, toxin.
Describe a series of food handling missteps that are likely to result in enterotoxin food poisoning.
1. Unsanitary handling and storage (contaminated with enterotoxin producing bacteria)
2. Food is left at room temperature to grow and release enterotoxins
3. Food may be reheated, which kills bacteria but heat-stable enterotoxins survive
4. Food is eaten and illness occurs
What is dysentery?
infection of the intestines resulting in severe diarrhea with the presence of blood and mucus in the feces.
Why is enteritis more likely to cause dysentery than enterotoxin food poisoning?
Infections of the large intestine are more serious than the small intestine. Overall enteritis lasts longer and produces more longer symptoms, compared to enterotoxins short incubation and short recovery.
What is the causative agent, reservoir, and symptoms of cholera?
Causative agent: Vibrio cholera (gram negative vibrio)
Reservoir: ocean water, humans
Symptoms: watery stool, vomiting, rapid dehydration which can lead to shock, organ failure, and even death!
What is the moratality of cholera?
if untreated, 50%. with treatment, less than 1%.
What is the mechanism of action for cholera?
cholera toxin (exotoxin) interacts with intestinal cells and causes cells to secret ions into intestinal lumen. Water follows those lumen, leading to severe dehydration and extremely watery stools.
Why does filtering water through cloth prevent cholera?
Cholera is usually attached to larger organisms (crustaceans, algae, plankton) so we can catch these bacteria containing organisms.
What are E. coli Gastroenteritis' reservoir and mode of transmission?
Reservoir: cattle gut (found in 10% of domestic cattle)
Mode of transmission: contaminated food (vehicular)
What are E. coli Gastroenteritis' virulence factors and symptoms?
Virulence factors: adheres to intestinal cells and destroys microvilli
-Contains enterotoxins that cause dysentery
Symptoms: SEVERE dysentery, fever
Explain how virulent strains of E.coli can contaminate ground beef, lettuce and spinach, and apple juice.
-Beef (contaminated at slaughter)
-In vegetables or fruit, can be contaminated through feces-contaminated water.
Other sets by this creator
Basic Functions of the Cell
Microbiology Week 1: Prokaryotic and Eukaryotic Ce…
Microbiology Week 1: History of Microbiology
Microbiology Week 15: Virology Life Cycle & Transd…
Other Quizlet sets
Unit 4 Vocab
2021 8th Grade Science Review
Microbio Week Two