Exam 3 (Helicobacter, Pseudomonas, Bordetella, Corynebacterium) Flashcards
Gram type and shape of Helicopbacter pylori
- G-
- vibrio rod
Mech of urease for H. pylori.
converts urea to ammonia which increases pH of stomach acid
Mech of VacA?
protein acts on gastric mucosal epithelia and promotes flow of urea to stomach
Significance of CagA protein?
inject by H. pylori into epithelia and can lead to cancer
Urease, VacA, CagA, mucinase, and flagella are all virulence factors of what bacteria?
Helicobacter pylori
How are gastric ulcers formed?
orgs survive acidity of stomach with urease, mucinase penetrates mucus, ors penetrate epithelial cell where they incite inflammatory response
___ to ___% of infected individuals will develop ulcerations. More than ___% of individuals with stomach cancer are infected with ___________.
- 10 to 20%
- 90%
- Helicobacter pylori
Most people infected with H. pylori have ______
no symptoms (symptom free carrier)
Pseudomonas aeruginosa Gram: Shape: Flagella?: Oxygen Req: Nut Req: Temp range:
Gram: G- Shape: Rod Flagella: polar, one or more, high mobility O2 Req: Obligate aerobe Nut Req: acetate Temp Range: 20 to 43 C (Broad)
Significance of alginate virulence factor. What organism is this in?
- adherence, protects from dehydration, immune evasion, biofilm formation
- Pseudomonas aeruginosa
What part of Pseudomonas aeruginosa interacts with CFTR?
Cystic Fibrosis Transmembrane conductance Regulator
-Lipopolysaccharide
Pseudomonas aerugeniosa are ______ pathogens.
opportunistic (nosocomial hospital)
P. aeruginosa is common in _____________, resistant to many __________ (like_____), and has _________ based resistance to many antibiotics.
- water/soil (hot tubs)
- disinfectants b/c of capsule
- like iodine
- R-plasmid
What bacteria is characterized by soluble blue-green dye (pyocyanin and pyoverdin)?
Pseudomonas aeruginosa
What What bacteria is known for it’s nosocomial infections of respiratory patients (especially cystic fibrosis pts)?
P. aeruginosa
Bordetella pertussis Gram: Shape: O2 req: Motility: Capsule:
Gram: G- Shape: coccobacilli (short rods) O2 Req: strict aerobe Motility: none Capsule: yes
Where do Bordetella pertussis grow in host?
dense surface growth with mucus production in lower respiratory tract (bronchi and bronchioli)
NO CELL INVASION
3 Toxins of B. pertussis?
- Pertussis toxin ptx (ADP ribosylation = incr cAMP = incr mucus and other secretions
- secreted invasice adenylate cyclase/hemolysin = incr cAMP
- tracheal cytotoxin (Nitric Oxide release) kills ciliated cells (component of peptidoglycan disacc-tetrapeptide)
Why do B. pertussis capsules release tracheal cytotoxin while other G- do not?
B. pertussis is not capable of recycling TCT within cell wall with a transporter protein while others can
Transmission and treatment of b. pertussis?
- aerosol transmission from adult reservoirs to children
- DTaP vaccine (Diphtheria, Tetanus, acellular Pertussis)
Corynebacterium diphtheriae
Gram:
Shape:
Gram: G+
Shape: pleiomorphic rods (club shaped)
Corynebacterium diphtheriae are ____________ pathogens. They are also __________ pathogens with ___________ effects.
- opportunistic
- oral
- systemic
Other than throat adhesion, what is the only virulence factor of C. diphtheriae?
-diphtheria toxin
Mechanism of action of diphtheria toxin?
A-chain of toxin inhibits ADP-ribosylation of elongation factor 2. This prevents ribosomes from moving down mRNA and doing prot synth
What is the pseudomembrane made by C. diphtheriae made of?
-bacterial cells + damaged host cells + blood
Disease risks of C. diphtheriae toxin? Local vs Systemic
Local: esophageal paralysis, suffocation
Systemic: cardiac arrhythmia, kidney failure
Spread and treatment of Corynebacterium diphtheriae?
Spread: saliva droplets
Tx: prevent by toxoid vaccination
What three diseases were nearly erradicated by vaccination in the 1920s?
Diphtheria, Pertussis, Tetanus
