Micro Mycoplasma

Front 1

What is unique about Mycoplasmataceae?

Back 1

They lack a peptidoglycan cell wall, and only protective layer is a cell mm packed with sterols. Therefore, they can contort shapes and are not rods or cocci.

Front 2

Since Mycoplasmataceae lack a cell wall, what drug is ineffective?

Back 2

Antibiotics that attack cell wall (penicillin, cephalosporin)

Front 3

What does Mycoplasma pneumoniae cause?

Back 3

A mild, self-limited bronchitis and pneumonia.

Front 4

Mycoplasma pneumoniae is the number one cause of? Extrapulmonary syndromes?

Back 4

Bacterial tracheobronchitis and pneumonia (atypical pneumonia, walking pneumonia) in teenagers and young adults.

Adult respiratory distress syndrome, pericarditis, myocarditis, hemolytic anemia (associated with cold agglutinin IgM)

Front 5

What is "walking pneumonia"?

Back 5

After incubation period, PTs have gradual onset of fever, sore throat, malaise, and persistent dry hacking cough. Clinically, these PTs do not feel very sick.

Front 6

PTs with M. pneumoniae can develop also develop?

Back 6

Erythema multiforme or Steven's Johnson syndrome, a skin reaction with erythematous vesicles and bullae over the mucocutaneous junctions of the mouth, eyes and skin.

Front 7

How can you diagnosis M. pneumoniae?

Back 7

Cold hemagglutination (IgM); fried-egg appearance (2 - 3 wk culture on Eaton's agar); serology

Front 8

How do you treat M. pneumoniae?

What's the DOC?

Back 8

Upper respiratory infection need not be treated; walking pneumonia treatment will shorten course and severity.

Treat with "atypical coverage" (macrolides, tetracyclines, and quinolones) since they will cover atypical bacteria: Mycoplasma, Legionella, and Chlamydia.

DOC: erythromycin or doxycycline (newer macrolides and fluoroquinolones are better tolerated; however, they are more expensive).

Front 9

What are two Mycoplasma that cause genital infections, such as urethritis?

Back 9

Ureaplasma urealyticum (produces urease to break down urea into ammonia and carbon dioxide) and Mycoplasma hominis

Front 10

What is shown on x-ray with Mycoplasma pneumoniae?

Back 10

Streaky or patchy infiltrate, which looks worse than the clinical symptoms and physical exam suggest.

Front 11

7% of people with Mycoplasma pneumonia can develop?

Back 11

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

Front 12

What is cold agglutinins?

How do you test for it?

Back 12

Mycoplasma pneumonia can develop into monoclonal IgM ABs directed at RBC antigen called "I" antigen.

The AB causes the RBC to agglutinate at 4d C.

Place PTs blood into a tube on ice, and it will clump together if the PT has developed cold agglutinin ABs.

Front 13

How do you perform the complement fixation test?

Back 13

PT's serum is mixed with glycolipid antigens prepared from Mycoplasma. A fourfold rise in AB titer between acute and convalescent sample is diagnostic of a recent infection.

Front 14

Mycoplasmas are the?

Back 14

Smallest free-living, self-replicating organism.

Front 15

What are the four of the most important characteristics of atypical pneumonia?

Back 15

Nonproductive cough; variable chest x-ray (patchy, diffuse infiltrates); no bacteria on *Gram stain; no response to beta-lactam antibiotics.

On Eaton's agar with difficulty

Front 16

How is M. pneumoniae spread? What is the risk group?

Back 16

Person-to-person.

5 - 20 year olds. Outbreaks are common in crowded military and institutional settings that can last for several months.

Front 17

How does M. pneumoniae cause a cough?

Back 17

It produces hydrogen peroxide, which is cytotoxic to the respiratory mucosa, inhibiting ciliary movement (ciliostasis) that allows the bacteria to adhere, resulting in prolonged cough.

Note: the hydrogen peroxide can also cause hemolytic anemia in uncommon cases.