LRT II & III Flashcards
What are the bacteria that fall into the walking or atypical pneumonia category?
Mycoplasma pneumoniae
Chlamydophila pneumoniae
Legionella pneumophila
Is the onset abrupt or gradual for atypical pneumonia? What are the associated symptoms?
Gradual
fever, HA, fatigue, myalgias, dry cough
What is the treatment for atypical pneumonia?
Tetracycline and erythromcin
True or false: you treat atypical pneumonia empirically?
True
What is the smallest living bacteria?
Mycoplasma pneumoniae
What is mycoplasma pneumoniae’s morpholoy? What is the colony morphology?
Morph = pelomorphic
Fried egg appearing colonies
What is in the membrane of mycoplasma pneumoniae that it robs from humans, since it cannot produce it on its own?
Sterols
Does mycoplasma pneumoniae have a peptidoglycan layer? What is the significance of this?
No, thus cannot use beta lactams or abx that target cell wall
How does mycoplasma pneumoniae spread? How much bacteria is needed to cause disease?
Through large droplets, with small number of bacteria needed
What is the other major disease that mycoplasma pneumoniae causes, besides pneumonia?
Tracheobronchitis
What is the major virulence factor that mycoplasma pneumoniae produces? What is its function?
P1 adhesin–binds to base of cilia, allowing ciliary stasis and cell death
What is the MOA of how mycoplasma causes anemia?
IgM produced against mycoplasma is cross reactive with RBCs
What is the best way to diagnose mycoplasma pneumoniae? Which way would you not use?
PCR or serology
NOT culture
What is the treatment for mycoplasma pneumoniae?
Tetracycline and macrolide
What is the agglutination test?
Test to see at what temp RBCs aggutinize at. Normal = 37 C, abnormal = 4 C
Which type of abx do you never use against mycoplasma pneumoniae? Why?
Beta lactams, because they do not have a cell wall
What is the prognosis for mycoplasma pneumoniae?
Self -limiting in 2 weeks
What can be done to prevent infx with mycoplasma pneumoniae?
avoiding it, no vaccine
What is the gram stain, metabolic, and morphology of chlamydophila pneumoniae?
Small, gram negaviet obligate intracellular pathogen
What type of pneumoniae does chlamydophila pneumoniae cause (typical or not)?
Atypical
How do you diagnose chlamydophila pneumonaie?
PCR or ELISA
What is the treatment for chlamydophila pnuemoniae?
Tetracyline and a macrolide (same as mycoplasma pneumoniae)
What is significant about the infection process of chlamydophila pneumoniae?
Reticulate bodies (non-infx) and elementary bodies (infx)
What is the causative agent of legionnaires disease?
Legionella pneumonophila
What are the two diseases that legionella causes?
Legionnaires disease, and pontiac fever
What is pontiac fever?
Mild, self limiting disease caused by legionella pneumonphila. Much more common.
What is the gram stain and morphology of legionella?
Gram negative coccobacilli (inside of cell). Pleomorphic outside cell
Where does legionella pneumophila usually exist?
Freshwater lakes, streams, ground water.
How is legionella pneumopha transmitted to humans?
Aersols from manmade water supplies, ACs etc
How does legionella infect the body? (What is the cell target?)
Targets and attaches to alveolar macrophages, and prevents fusion with lysosome
What is the unique histological characteristic to legionella?
Coiling phenomenon inside macrophages
What is the pathogenesis of legionella?
Hjacks cell by injecting a ton of toxins. Recruits macrophages to produce itself. Lyses the macrophage
What causes the lung necrosis seen in an infx with legionella?
Lysis of macrophage, and emission of bacterial toxins
What are the clinical manifestations of legionnaries disease?
Severe, toxic pneumonia
Myalgias
HA/confusion
Rapid fever
Diagnosis of legionella is done how?
Leukocytosis with L shift
Direct fluorescent antibody
nucleic acid synthesis
What is the treatment foe Legionnaires disease? What is the abx type that is not effective in treatment?
Macrolide or fluoquinolone
NOT beta lactams
What is the gram stain of mycoplasma TB?
Weakly gram positive
What is in the cell wall of mycoplasma TB, that is distinct?
tons of lipids
What is the stain that can identify TB? How does this work?
Acid fast-stains the mycolic acids
What are the 6 components of TB’s cell wall?
Membrane Peptidoglycan arabingalactan Lipoarabinomannin Plasma membrane Mycolic acid
True or false: TB has many reservoirs in the environment
False–only humans
How is TB spread?
Person to person contact