Streptococcus pneumoniae Flashcards
what are the growth characteristics of S. pneumo?
not fastidious
aerotolerant anerobe
catalase negative
What are the virulence factors of S. pneumo?
Capsular polysaccharide
Pneumolysin
What type of pneumoniae is S. pneumo the major bacterial cause of?
CAP
d/t aspiration by the pt
how is S. pneumo trasmitted?
via respiratory droplets
what is the POE of S. pneumo?
RT
what age is the highest incidence of S. pneumo found?
children <5 yo
elderly
what is the seasonality of S. pneumo?
winter, d/t:
antecedent viral infx
risk of exposure d/t crowding
What are key predisposing factors that separate S. pneumo from other acute bacterial agents?
sickle cell disease
innate/acquired immune defect
how many serotypes account for >90% of infx?
23
what is the pathogenesis of S. pneumo?
consolidation pneumonia
what will CXR of S. pneumo infx show?
patchy infiltrates more common than consolidation
clinical buzz words for S. pneumo
- rusty sputum
- single bout of teeth chattering chills
Does S. pneumo produce abscesses?
no
does S. pneumo cause necrotizing pneumonia?
usually not
What is the main complication of S. pneumo?
bacteremia (occurs in 1/3 cases)
what is invasive pneumococcal disease (IPD)?
agent is found in normally sterile site (i.e. blood)
what epidemiological group is IPD usually found in?
children with chronic diseases
how is S. pneumo differentiated from a-hemolytic NMF from oropharynx?
optochin sensitivity
MOPS: S. pneumo are most OPtochin Sensitive
what is the normal treatment for S. pneumo infection?
penicillin
what causes penicillin resistance in DRSP?
mutations in PBP
what epidemiological group is most likely to carry antibiotic resistant strains of S. pneumo?
young children more than adults
-resistant serotypes usually cause pediatric infx
how can S. pneumo infx be prevented?
Pneumovax/Pnu-immune
what is the valency of the S. pneumo vaccine?
23 valent
who should the S. pneumo vaccine be given to?
pts >65 yo
pts 2-65 yo with chronic disease
immunocompromised pts
