streptococcus pneumoniae Flashcards
high yield
what is the biology of strep. pneumoniae?
gram positive diplococcus flame-shaped with a polysaccharide capsule
where is strep pneumoniae soluble?
bile soluble
strep pneumoniae is what type of gram?
positive
what type of hemolysis occurs with Strep. pneumoniae in blood agar? (alpha, beta, or gamma?)
alpha
does strep pneumoniae have a capsule?
if yes, what is its functional purpose?
yes, it protects it from phagocytes
is strep pneumoniae bile soluble?
yes
where is strep pneumoniae soluble?
in bile
what is sensitive (inhibits growth) to strep pneumoniae?
optochin
is strep. pneumoniae catalase + or -?
it is negative
what else is catalase negative?
enteroccoci
what helps detect the polysaccharide capsule of strep pneumoniae?
quellung reaction
what does strep pneumoniae have to damage cells in the body?
Pneumolysin
when vaccinating against strep pneumoniae, what bacterial part is the vaccine targeting?
the polysaccharide capsule
what 3 tests can be done to differentiate strep pneumoniae from strep viridans?
Bile soluble
Optochin sensitive
Positive quellung reaction
what helps protect strep pneumoniae in the body?
IgA protease
what is pneumolysin?
It is a cytotoxin that binds to host cell membranes and goes to the pores
what is pneumolysin going to do to cells?
What cells are affected?
- it will destroy host cells, especially:
- Ciliated epithelial cells
- Phagocytic cells
and
- Suppresses phagocytic cell oxidative burst
what diseases will strep pneumoniae cause?
Pneumonia
Meningitis
Otitis media
Sinusitis
what other bacteria can cause the same diseases as strep pneumoniae?
haemophilus influenza
what is the most common cause of Community-acquired lobar pneumonia?
strep pneumoniae
what symptoms can be seen in Community-acquired lobar pneumonia?
- shaking chills, high fever
- Productive cough with blood-tinged sputum * (“rusty sputum”)
what patients are at high risk of serious infection with Community-acquired lobar pneumonia?
elderly
asplenic
where do you find strep pneumoniae?
in upper resp. tract
how does strep pneumoniae spread?
through respiratory droplets
what factors predispose patients to strep pneumoniae?
previous viral resp. infection (measles or influenza)
asplenia (whcih can lead to septicemia)
Chronic obstructive pulmonary disease (COPD)
what is the most common cause of adult meningitis?
strep pneumoniae
what symptoms can be seen in adult strep pneumoniae?
High fever
Nuchal rigidity
Photophobia
Nausea, vomiting
what test can be done to confirm a case of meningitis due to strep pneumoniae?
what will be the findings?
spinal tap
gram stain showing neutrophils and GPS pairs
High neutrophils *
Low glucose *
Capsular antigen detected
what is one of the most common cause of sinusitis and middle ear infection?
strep pneumoniae
what predisposes to strep pneumoniae leading to sinusitis and otitis media?
a previous infection with the common cold
what is the mechanism of resistance used by strep pneumoniae?
alteration of PBP’s
30-40% of strep pnumoniae is resistant to what drug?
penicillin
serious strep penumoniae infection can be treated with what drug?
Vancomycin + ceftriaxone
what drug is used in children with strep pneumoniae caused sinusitis and otitis media?
erythromycin
what prevention to strep pneumoniae exists for higher risk patients?
vaccination
the vaccine for strep pneumoniae uses what from the bacteria?
the capsule
