Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
29 Cards in this Set
- Front
- Back
What are the two non-spore forming G+ rods?
|
Corynebacterium diptheriae
Listeria monocytogense |
|
What are the oxygen requirements of the two non-spore forming G+ rods?
|
Facultative anaerobic
|
|
What is the morphology of C. diptheriae?
|
Small
Pleomorphic Unencapsulated G+ rods |
|
How are collections of C. diptheriae commonly described?
|
Chinese characters
|
|
How is C. diptheriae usually spread?
|
Respiratory droplets
|
|
How can one become infected with C. ditheriae other than by respiratory droplets?
|
Puncture wound or cut
|
|
What is the pathogenesis of diptheria?
|
Absorption of an exotoxin composed of an A and a B fragment.
|
|
How does this diptheria toxin affect the cell?
|
Inhibits eukaryotic protein synthesis
|
|
What is the role of fragment A in diphtheria toxin?
|
Adenosine diphosphate ribosylation of elongation factor-2 resulting in EF-2 inactivation and blockage of the translocation of polypeptidyl-transfer ribonucleic acid. (tRNA).
|
|
What is the role of fragment B in diphtheria toxin?
|
Binding to cell and delivery of fragment A
|
|
Where is the toxin encoding diphtheria DNA found?
|
In a bacteriophage
|
|
Which strains of bacteriophages can produce C. diptheriae capable of active infection?
|
Lysogenic strains
|
|
Why can lysogenic strains produce C. diphtheriae capable of active infection?
|
Lysogeny allows bacteriophage integration into the bacterial genome and toxin (protein) expression.
|
|
Where is the toxin encoding diphtheria DNA found?
|
In a bacteriophage
|
|
Which strains of bacteriophages can produce C. diptheriae capable of active infection?
|
Lysogenic strains
|
|
Why can lysogenic strains produce C. diphtheriae capable of active infection?
|
Lysogeny allows bacteriophage integration inot the bacterial genome and toxin (protein) expression.
|
|
Where does C. diphtheriae usually infect humans?
|
Throat and nasopharynx
|
|
What is a classic clinical manifestation of C. diphtheriae infection?
|
Pseudomembrane pharyngitis.
|
|
What is psdudomembrane pharyngitis.
|
An adherent, thick and gray exudateive pseudomembrane forming in the throat or nasopharynx with lymphadenopathy
|
|
What are two rare clinical manifestations of diphtheria?
|
Myocarditis
Neuritis of cranial nerves |
|
How does the host neutralize the toxin?
|
Antibody formation
|
|
How is clinical C. diphtheriae diagnosed?
|
Although no quick and reliable lab tests exists, cultures may yield G+ rods with blue and red granules.
|
|
How is C. diphtheria definitively diagnosed?
|
Isolation of C. diphtheriae via potassium tellurite containing Tinsdale agar and demonstration of toxin production via precipitin reaction.
|
|
How is diphtheria treated?
|
Empiric treatment, i.e., immediate administration of hores serum antitoxin and antibiotics.
|
|
Which antibiotics can be used?
|
Penicillin g and erythromycin
|
|
How is diptheria prevented
|
DTaP vaccine
|
|
What are diphtheroids?
|
Corynebacterium species similar to C. diphtheriae.
|
|
What patient population gets affected by diptheroids?
|
Immunosuppressed
|
|
Which antibiotic is used to treat diphtheroids?
|
Vancomycin
|