export_bacterial lrt ii Flashcards
Pathogens causing walking pneumonia
Mycoplasma pneumoniae
Pathogens causing toxic pneumonia
Legionella pneumophila
Symptoms of atypical pneumonia
Gradual onset
Fever
Headache
Muscle ache
Dry cough
Treatment of atypical pneumonia
Tetracycline and erythromycin - empiric therapy
Mycoplasma pneumoniae characteristics
Pleomorphic
No peptidoglycan
Membrane contains sterols (takes cholesterol from humans)
“Fried egg colony” morphology
Restricted to humans
Mycoplasma pneumoniae virulence factor
P1 adhesin
P1 adhesin
Binds to cilia, resulting in ciliostasis
Damages epithelial cells and results in defective mucociliary clearance
Symptoms of mycoplasma pneumoniae disease
Bronchopneumonia
Anemia - IgM cross-reactivity with RBCs
Diagnosis of mycoplasma pneumoniae
Cold agglutinin test
PCR
Serology
Treatment of mycoplasma pneumoniae disease
Tetracycline and erythromycin
NOT beta-lactams (no peptidoglycan)
Chlamydophila pneumoniae characteristics
Gram-negative, intracellular pathogen
What diseases are chlamydophila pneumoniae implicated in
Atherosclerosis
Asthma
MS
RA
Diagnose chlamydophila pneumoniae
Microimmunofluorescence
PCR
Treatment for chlamydophila pneumoniae
Tetracycline and erythromycin
Chlamydophila pneumoniae virulence
Elementary body reorganizes to form a reticulate body
Legionella pneumophila is causative agent for?
Legionnaires’ disease
Pontiac fever
Compare Legionnaires’ and Pontiac fever
Legionnaires’ - low attack rate, longer incubation period, causes pneumonia, requires antibiotics, and has a higher mortality rate
Pontiac - high attack rate, short incubation period, does not cause pneumonia, and has a very low mortality rate
Legionella pneumophila characteristics
Gram-negative
Difficult to culture
Ubiquitous in freshwaters
Mainly intracellular parasites of amoeba
Legionella pneumophila intracellular
Coccobacilli
Legionella pneumophila extracellular
Pleomorphic
Legionella pneumophila virulence
Target/attach to alveolar macrophage
Enter macrophage in endocytic vacuole (coiling phenomenon)
Legionella pneumophila cell hijacking
Type 4 secretion system
Prevents lysosomal fusion
Recruitment to LCV
Host cell lysis, repeat
Clinical manifestation of legionella pneumophila
Severe toxic pneumonia
Myalgia, rapid fever
Progressively ill over 3-6 days, shock, respiratory failure
Elevated WBCs
Diagnose legionella pneumophila
Direct fluorescent Ab (DFA)
Nucleic acid amplification test (NAA or NAAT) - PCR
Treatment for legionella pneumophila
NOT beta-lactams
A macrolide or fluoroquinolone
