Mycoplasma + Legionella Flashcards
Look up Moraxella catarrhalis
GN diplococci
Otitis media
sinusitis
Pharyngitis
Atypical pneumoniae x ray
diffuse peribronchial pulmonary infiltrates
- highly contagious
(as opposed to lobar with typicals)
Atypical pneumo. organisms
- Mycoplasma
- Legionella
- Chlamydia
- Virus (Influenza, CMV, RSV, adenovirus)
*strep pneumo is most comm cause of CAP
Mortality of mycoplasma pneumoniae
1%
Target of M. pneum in PCR
P1: terminal attachment protein to CILATED EPITHELIAL CELLS
- when tip structure comes in contact with epith cells, ciliostasis occurs and allows mucus to accumulate, facilitates microbial contamination of lower resp tract.
Top 3 clinical manifestations of M. pneumo if not asymp:
- Extrapulmonary manifestations (25-50)
- Upper Resp. Tract - pharyngitis, otitis media, tracheobronchitis
- Hematologic - hemolytic anemia (50%)
Toxin of M. pneumo
CARDS Toxin
- seq homology with S1 subunit of pertussis toxin
- has ADP ribosylating activity
- significant virulence factor
Cold agglutins
Complement fixation
autoantibodies that form on RBCs
Complement: Get pts sera used for epidemiology
*both are not useful, take too long
dxing M. pneumo
- a combination of PCR and serology
also
2. ELISA
What can you give to tx M. pneumo if macrolide resistant?
Doxycycline,
FQ,
levofloxacin,
moxifloxacin
*PCN ineffective since no cell wall
How to detect legionella
LPS Antigen detection in urine
Grow on charcoal yeast extract culture (with iron and cysteine)
Direct flourescent antibody staining on culture of sputum to S1
Legionnaire’s disease vs Pontiac fever caused by Legionella pneumophila
- Fatality
- Attack rate
- effects on lungs
- other organ systems affected
Legionnaires:
- 20% fatality
- attack rate: 1-5%
- Unilateral, lobar - Pneumonia, pleural effusion
- CNS, GI
Pontiac:
- No fatality
- Attack rate: 95%
- Pleuritis (no pneumonia)
- None
Intracellular bacteria that grow in a specialized endosome
- Legionella
- Toxoplasma gondii
- psittici
Intracellular bacteria that escape from the phagosome
- Listeria
- Rickettsia
- Trypanosoma cruzi
- Shigella
Intracellular bacteria that survive in a phagolysosome
- Leishmania
- M. Leprae
*most insidious of intracellular growth
Transmission of legionella by water
Potable (spec. for direct hu use)
- showers
- tap water
- respiratory care equipment
Do mycoiplasmas synthesize cholesterol?
Nope. PM contains sterols
Transmission of M. pneumoniae
Resp. droplets
- attackes to ciliated epithelial cells in trachea and bronchi of lower resp. tract.
Unique cytoskeletal structure of M. pneumo
participates in binary division and gliding motility
- has elongated shape when it attaches to surfaces (ciliated epithelium)
How does Legionella evade host defenses?
- Living w/in macrophages (facultative intracellular)
2. Inhibits endosome-lysosome fusion
Incidences of legionella occur more at what times of the year?
late summer, early fall
