Flashcards in Atypical Pneumonia Deck (19):
Features of Atypical Pneumonia
Insidious onset, extrapulmonary symptoms (muscle aches, heachache), usually no evidence of consolidation on exam, only low fever, WBC largely normal. Caused by mycoplasma pneumoniae, chlamydophilia pneumoniae, legionella.
Features of Typical Pneumonia
Abrupt onset, productive cough with copious sputum, evidence of consolidation on exam. WBC count elevated. Caused by Strep Pneumo.
Mycoplasma Pneumoniae effects in children and others
Others: Primary pneumonia.
How is mycoplasma transmitted?
Respiratory droplets. Close contact is necessary. Long incubation period.
How is mycoplasma unique?
Looks like a virus, but contains both DNA and RNA. Lacks a cell wall.
How does mycoplasma appear under the microscope?
Gram-null short rod. Can grow on cell-free medium. Takes many days to grow.
Mycoplasma extrapulmonary manifestations
Hepatitis, cold agglutinins, erythema multiforme
Mycoplasma virulence factor?
How to treat mycoplasma?
Macrolides (or tetracyclines), because they penetrate intracellular.
Chlamydophilia pneumonia transmission?
Respiratory droplets. Occurs in close quarters like barracks, nursing homes, college dorms.
Chlamydophilia pneumonia characteristics
Obligate intracellular bacteria, has a cell wall, has a life cycle that consists of reticulate and elementary body.
Chlamydophilia life cycle
Outside of cell, chlamydophilia survives as the elementary body (which is metabolically inactive). Inside, the cell, it becomes the reticulate body.
Chlamydophilia virulence factors
Legionella pneumophila appearance and characteristics
Small gram negative rod, obligate aerobe. Lives within amoebae in contaminated water.
Spread of legionella?
Through contaminated water aerosolization.
Legionella Virulence factors?
Toxins and proteases, pili, flagella, macrophage infectivity.
How does legionella infection proceed?
When organisms reach the lungs they are engulfed by alveolar macrophages. Legionella grow within the macrophages, kill them, then infect others. Neutrophils then invade, and a large inflammatory response is initiated.
How to detect legionella?
Look for serogroup 1 in urine.