RTI VI Flashcards
summarize community-acquired pneumonia and hospital-acquired pneumonia
list common typical causes of CAP
- Streptococcus pneumoniae
- H. influenzae
- Klebsiella
- Staph aureus
name clinical features associated with typical CAP
- usually one lobe involved
- acute onset, increased fever, pleuritic chest pain, productive cough
- signs of consolidation:
- dullness
- vocal fremitus/resonance
- egophony
- whispered pectoriloquy
- bronchial breath sounds
- Dx = CXR
describe the appearance of S. pneumoniae on blood agar
describe the appearance of S. pyogenes on blood agar
_____ is the commonest cause of community-acquired pneumonia
S. pneumoniae is the commonest cause of community-acquired pneumonia
describe the pathogenesis of Pneumococcal pneumonia
- capsule
- IgA protease
- pneumolysin
- autolysin
- transformation
describe properties of pneumolysin
describe the sputum seen in S. pneumoniae infection
rusty colored (reddish-brown)
describe prevention of Pneumococcal pneumonia and the high risk populations it is indicated for
- “polyvalent” capsular polysaccharide vaccine
- immunizes against 23 of the most common serotypes
- high risk individuals:
- age >65
- chronic disease
- HIV
- alcoholism
- splenectomy patients
Klebsiella is a (G+ve/G-ve) ____ (shape)
Klebsiella is a G-ve bacillus
Klebsiella has a large ____, which gives it a mucoid appearance
Klebsiella has a large polysaccharide capsule, which gives it a mucoid appearance
Klebsiella causes ____ of lung tissue, due in part to response to _____
Klebsiella causes necrotization of lung tissue, due in part to response to endotoxin (LPS)
name the at-risk individuals for Klebsiella infection
- CAP
- alcoholics
- diabetics
- COPD
- HAP
- ventilators
- IV catheters
describe the sputum seen in Klebsiella infection
“red currant jelly” sputum
in Klebsiella pneumoniae, 2 high affinity ___ uptake systems: _____& _____ helps in bacterial growth
in Klebsiella pneumoniae , 2 high-affinity iron uptake systems: aerobactin & enterochelin helps in bacterial growth
describe the role of the LPS in Klebsiella pneumoniae
- LPS (O antigen)
- prevents ingestion by phagocytes, detection of somatic antigens by host’s antibodies
- impedes complement (especially C3b); inhibits opsonization
Klebsiella pneumoniae produces ____ which gives it ____ resistance
Klebsiella pneumoniae produces carbapenemase which gives it carbapenem resistance
the ___ found in Klebsiella pneumoniae allows attachement to ____ and ____ formation
the pili (fimbriae) found in Klebsiella pneumoniae allows attachment to epithelium and biofilm formation
describe the spread of Klebsiella pneumoniae
exposure to bacteria required, person to person via contamination of hands or environment (NOT spread through air)
describe the Sketchy
Pseudomonas sp. is found in _____
Pseudomonas sp. is found in still fresh water sources
list the persons that are at highest risk for Pseduomnas infections
- particularly dangerous for persons with structural defects in body defenses:
- burn victims
- CF
- HAP
the most common infection caused by Pseudomonas sp. is _____
the most common infection caused by Pseudomonas sp. is otitis externa aka swimmer’s ear
Pseduomonas are (G+ve/G-ve) ____ (shape)
Pseduomonas are G-ve rods
describe the sputum color in Pseudomonas infections
blue-green/yellow-green sputum
_____ and ____ are considered as bona fide CF pathogens
Pseudomonas aeruginosa and Burkholderia cepacia are considered as bona fide CF pathogens
describe the Sketchy
list the most common atypical causes of CAP
- most common “atypical” causes:
- Mycoplasma pneumoniae
- Chlamydophila pneumoniae
- Legionella pneumophila
____ is the most common cause of atypical CAP
Mycoplasma pneumoniae is the most common cause of atypical CAP
describe features related to Mycoplasma pneumoniae lack of cell wall
- due to lack of cell wall:
- unreactive to Gram stain
- extremely susceptible to desiccation and intrinsically resistant to B-lactam antibiotics
describe where outbreaks of Mycoplasma pneumoniae commonly occur
- outbreaks lasting months occur in crowded institutional settings (military, colleges, prison, etc.)
describe adhesion molecules found in Mycoplasma pneumoniae
- specialized attachment organelle (P1 adhesin and accessory proteins)
Mycoplasma pneumoniae production of ____ mediates tissue destruction
Mycoplasma pneumoniae production of H2O2 mediates tissue destruction
Mycoplasma pneumoniae ____ leads to cytotoxic effect on the resp. epithelium during acute infection
Mycoplasma pneumoniae community acquired resp. distress syndrome (CARDS) leads to cytotoxic effect on the resp. epithelium during acute infection
Mycoplasma pneumoniae attaches to and damages ____ at the base of ___ which causes prolonged paroxysmal cough and activates the immune system
Mycoplasma pneumoniae attaches to and damages the respiratory epithelial cells at the base of cilia which causes prolonged paroxysmal cough and activates the immune system
describe the diagnosis of Mycoplasma pneumoniae
- serology:
- serum cold agglutination
- non-specific
- negative result does not exclude infxn
- > 4-fold increase or decrease supports the diagnosis
- serum cold agglutination
describe the Sketchy
