Micro Upper GI Zimmer Flashcards
What does microbiome usually refer to?
Normal flora in large intestine
Infectious diseases that cause tooth to decay
Caries
Risk factors for caries:
High-sugar diet Poor oral hygiene Reduced saliva Smoking Periodontal disease (related diseases of surrounding gums)
What mechanism of microbes causes damage and significant illness?
GROWTH AND SPREAD of microbes!
Tx for dental carries?
Drill out decayed area of tooth and put in a filling
Periodontitis
Infection of underlying tissues and bones
What is the mechanism that causes illness in gingivitis and periodontitis?
HOST IMMUNE RESPONSE to microbe
Gingivitis
Infectious disease destroying supporting structres of teeth
What is essential for microbes to produce to cause dental disease?
BIOFILM
What is a biofilm?
2 or more species of bacterial micro-colonies that are enclosed in a glycocalyx
What general class of organisms predominate in the mouth? Aerobes or anaerobes
ANAEROBES!
How do species of oral streptococci play a role in protecting against dental carries and periodontitis?
Producing Hydrogen peroxide which inhibits growth of other oral bacteria
Is S. mitis pathogenic or non-pathogenic?
NON-Pathogenic
*Common in test questions
Are the bugs that cause caries usually gram + or -?
Gram +
Are microbes that cause periodontal disease in the subgingival space usually gram + or gram -?
Gram -
What strep species is often involved in caries?
Strep mutans
Virulence factor
*Broader than “toxin”
*Include bacterial toxins under the umbrella
Properties enabling a microorganism to establish itself on or within a host and enhance its potential to cause disease
Toxins
Promote infection and disease by directly damaging host tissues and by disabling the immune system
What are the virulence factors of Strep Mutans?
Adhesin-like surface-associated proteins that are capable of binding to receptors in the pellicle (Ex. AgI/II family)
Extracellular glucosyltransferases (Gtfs) are constituents of the pellicle and are capable of synthesizing glucans (a type of polysaccharide) from sucrose. Glucans provide additional S. mutans binding sites, as it binds avidly and in large numbers to these polymers.
Porphyromonas gingivalis
Gram + or -?
Baccilus or cocci?
Aerobe or anaerobe?
Appearance on blood agar plates?
Bacitracin sensitive or resistant?
A “keystone pathogen”–well studied because it can be cultured.
Remodels a normally symbiotic microbiota into a dysbiotic state
Gram - Bacillus
Black-pigmented colonies
Bacitracin resistant
“It’s kind of like you have one bad guy come in and there goes the neighborhood.” “Things just aren’t what they used to be.”
How does consuming less sugar in the diet help prevent caries and periodontal disease?
Less chance of existing biofilm becoming more pathogenic
Why is fluoride important?
Inhibits bacterial glycolysis and pH maintenance enzymes
Remineralization to counteract the effects of demineralization under low pH conditions
Is gingivitis reversible or irreversible?
Reversible
What is the link between Diabetes and Periodontal disease?
Risk of periodontitis is up to 3-fold if you are diabetic
When you do have periodontal disease…it has a negative impact on glycemic control
*They make each other worse but what is the link that connects them!?
If you are diabetic, you have elevated levels of inflammatory markers…so when you have a microbial bacterial infection in your mouth, your inflammatory response is going to be more robust than it would normally be!Even if you have a small level of bacteria you will have gingivitis if you are diabetic
Virus that causes Hairy Leukoplakia
EBV
What is Ludwig’s angina?
Skin infection on floor of mouth…usually results from untx dental infections.
Swelling of infected area may block the airway or prevent swallowing of saliva!
*Redness of the neck is hallmark
Other sx: Fever, breathing difficulty, neck swelling, neck pain
What bacteria can be responsible for Ludwig’s angina?
Alpha-hemolytic streptococci
Staph
Bacteroides
Thrush location?
Tongue and inner cheeks
What location of candidiasis is super dangerous?
Esophageal
Most common tx for Candidiasis?
Nystatin (swish and swallow)
Clotrimazole lozenge
What do you use to treat unresponsive cases of candidiasis?
Systemic Fluconazole
Worst case tx of candidiasis?
IV administration of Amphotericin B
Pseudomembrane that is gray and solid in the back of the throat makes you think??
C. diptheriae
Is Leukoplakia caused by a microorganism?
NOOO
Thought to be caused by smoking and chewing tobacco or other irritations
EBV (HHV-4) virus properties
Double stranded DNA
Linear
Enveloped
H. pylori properties
Gram - Flagellated helix-shaped rod (spirilli) Microaerophilic Catalase and oxidase + Urease +
Risk of H. pylori-positive patients developing ulcer disease?
10 -20 %
Risk of H.pylori-positive patients developing distal gastric cancer?
1-2 %
Main way that H. pylori results in disease (gastritis and peptic ulcer)
Host-immune response
*Also some involvement in toxin production
How does H pylori evade the immune system?
Inhibits phagocytic uptake
Inhibits adaptive immune response
Evades killing by ROS and NO
Evades Recognition by Pattern Recognition receptors
What does urease do for H pylori?
Raises local pH…the creation of ammonia is what raises the pH.
It creates a better environment for H pylori to live!
What does H pylori use flagella for?
Allows it to get through the low pH layer of mucus and down into a higher pH immediately atop epithelial cells where it can survive
How does H pylori use adherence to its advantage?
Allows some cells to avoid mechanical clearance
Promote invasion and persistence
Adhesions contribute to inflammation
What is VacA?
Pore forming cytotoxin of H pylori that allows leakage of Ca+ from epithelial cells
What is CagA?
Type 4 secretion system (TFSS) is a needle through which CagA travels into host cytosol and affects the proliferative activities, adhesion, and cytoskeletal organization of epithelial cells.
It is HIGHLY PROINFLAMMATORY. CagA is now known to interact with at least 10 host proteins.
How does H pylori cause an ulcer?
Attracts inflammatory cells so the host damages itself by continual ineffective immune response
Gold standard test for H pylori
Endoscopy to biopsy
Tx for H pylori
Antibiotics (clarithromycin, amoxicillin)
PPI
What does the Breath Test for H pylori detect?
Radioactive CO2
What does the blood test for H pylori detect?
Antibodies for H pylori
*useful for initial dx only, not useful for confirming cure
Stool antigen test for H pylori
Easy
Good for Dx
Good for confirming cure
*It is a DIRECT ANTIGEN TEST: so it can differentiate between active and latent infection whereas serology only detects exposure
What is MALT?
Mucosa-associated lymphoid tissue in the stomach caused by H pylori
Tumors of B cells
What 2 cancers are H pylori associated with?
MALT
Gastric Carcinoma
How is H pylori associated with esophageal adenocarcinoma?
REDUCED RISK
Properties of diptheriae?
Gram + Rod
