Helicobacter, Pseudomonas, Bordetella, Cornyebacterium (EXAM III) Flashcards
Describe the gram stain & shape of helicobacter pylori:
Gram negative; virbrio (curved-spiral rod)
Curved spiral rod shape some bacteria take on:
Vibrio
List the virulence factors of helicobacter pylori:
- urease
- VacA
- CagA
- mucinase
- flagella
Describe the role of the virulence factor “urease”, in helicobacter pylori infection:
Urease breaks down urea into ammonia causing a pH increase leading to the neutralization of stomach acid
Describe the role of the virulence factor “VacA”, in helicobacter pylori infection:
this is a protein that acts on gastric mucosal epithelia to promote flow of urea into the stomach
Describe the role of the virulence factor “CagA”, in helicobacter pylori infection:
this is a protein that is injected into host epithelia that causes cell changes (prelude to cancer)
Describe the role of the virulence factor “mucinase”, in helicobacter pylori infection:
this is an enzyme that degrades the mucous layer allowing for the bacteria to penetrate
Describe the role of the virulence function of flagella in helicobacter pylori:
Very important for the colonization on the epithelial surface of the stomach
In helicobacter pylori, this breaks down urea into ammonia causing a pH increase leading to the neutralization of stomach acid
Urease
In helicobacter pylori, this is a protein that acts on gastric mucosal epithelia to promote flow of urea into the stomach
VacA
In helicobacter pylori, this is a protein that is injected into host epithelia that causes cell changes (prelude to cancer)
CagA
In helicobacter pylori, this is an enzyme that degrades the mucous layer allowing for the bacteria to penetrate
Mucinase
VacA is also a _____ that induces damage to cells
Cytotoxin
What allows helicobacter pylori organisms to survive the acidity of stomach juices?
Urease
Once the helicobacter pylori reach the mucous layer they penetrate the epithelial surface causing:
An inflammatory response
Helicobacter pylori’s ability to thin the mucous lining will cause:
Ulcers in 10-20% of infected individuals
Only a small percentage of individuals infected with helicobacter pylori will develop cancer however:
more 90% of individuals with stomach cancer are infected with H. Pylori
In most people with H. Pylori infections, they present
Symptom-free
Describe the gram stain & shape of pseudomas aeruginosa:
Gram negative; short rods
Describe the flagella on psuedomonas:
They are polar; one or more; allow high mobility
Describe the oxygen requirements for pseudomonas aeruginosa:
Obligate aerobe
Describe the nutrient requirements of pseudomonas aeruginosa:
Simple nutrient requirements- able to grow on hundreds of carbon sources for example
What is the temperature range in which pseudomonas aeruginosa can grow & multiply:
Broad temperature range; 20-43 degrees celcius
List the virulence factors of pseudomonas aeruginosa:
- Aliginate
- Lipopolysaccharide
What is the function of the virulence factor “alginate” in pseudomonas aeruginosa?
Adherence, protection from dehydration & immune invasion, a source of biofilm formation
What is the function of the virulence factor lipopolysaccharide in pseudomonas aeruginosa?
- Lipid A portion is endotoxic
- core interacts with cystic fibrosis transmembrane conductance regulator (CFTR)
- O antigen protects from complement-mediated killing
CFTR=
Cystic fibrosis transmembrane conductance regulator
Pseudomonas aeruginosa is considered a _____ pathogen
Opportunistic
Give examples of when pseudomonas aeruginosa may cause opportunistic infection:
- Cancer
- Cystic fibrosis
- Disease or weakened immunity
Pseudomonas aeruginosa is common in the:
Environment (water + soil)
What is an example of a perfect culture condition for pseudomonas aeruginosa?
Hot tub
Why might a hot tub be an ideal environment to grow pseudomonas aeruginosa?
Pseudomonas are heat tolerant
Pseudomonas aeruginosa are resistant to:
- Many chemical disinfections (like iodine)
- Many antibiotics
What allows for pseudomonas aeruginosa to be resistant to many antibiotics?
R-plasmid
What allows pseudomonas aeruginosa to be resistant to many chemical disinfectants?
Capsule & alignate
Pseudomonas aeruginosa are a major problem in:
Hospitals due to nosocomial infections