Chapter 16: Mycoplasma Flashcards Preview

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Flashcards in Chapter 16: Mycoplasma Deck (10):

What are mycoplasmataceae?

tiniest free-living organisms capable of self-replication
Lack peptidoglycan cell wall
Only protective layer is cell membrane packed with sterols to help shield cell organelles from exterior environment
Can contort into a broad range of shapes


Mycoplasma penumonia causes what?

mild, self-limited bronchitis and penumonia


What is the number one caue of bacterial bronchitis and pneumonia in teenagers and young adults?

Mycoplasma pneumoniae


What is the pathogenesis of mycoplasma pneumoniae?

Transmission via respiratory route
Organism attaches to respiratory epithelial cells with the help of protein P1
2-3 week incubation period
Gradual onset of fever, sore throat, malaise, and persistent dry hacking cough

Walking pneumonia - do not feel very sick

Most symptoms resolve in a week, cough and infiltration 2 months


Describe the chest x-ray of a pt with Mycoplasma pneumoniae

streaky infiltrate, seem more consistent with viral (atypical) pneumonia


7% of pts infected with Mycoplasma pneumonia can develop what symptoms for unclear reasons?

erythema multiforme or Stevens-Johnson syndrome: severe skin reaction characterized by erythematous vesicles and bullae over the mucocutaneous junctions of mouth, eyes and skin


What are the diagnostic tests for Mycoplasma pneumonia?

Cold agglutinins: IgM antibodies directed at common red blood cell antigen (I) that are modified with infection. clump at low temps
Complement fixation test: fourfold rise in antibody titer = recent infection
Sputum culture: artificial media rich in cholesterol, fried-egg appearance 3 weeks = mycoplasma
round bumpy mulberry with no halo = mycoplasma pneumonia
Mycoplasma DNA probe


Describe Ureaplasma urealyticum. What does it commonly cause?

sometimes referred to as T-strain Mycoplasma (produces tiny colonies when cultured)
Ureaplasma is in urine and produces urease to break down urea
Normal flora in healthy sexually active women (60%)

Commonly infects lower urinary tract causing urethritis


What is urethritis?

infection of urinary tract. Buring on urination (dysuria) and sometimes a yellow mucoid discharge from the urethra


What causes urethritis?

Neisseria gonorrhoeae, Chlamydia trachomatis, and ureaplasma urealyticum