streptococcus pneumoniae Flashcards

high yield (37 cards)

1
Q

what is the biology of strep. pneumoniae?

A

gram positive diplococcus flame-shaped with a polysaccharide capsule

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2
Q

where is strep pneumoniae soluble?

A

bile soluble

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3
Q

strep pneumoniae is what type of gram?

A

positive

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4
Q

what type of hemolysis occurs with Strep. pneumoniae in blood agar? (alpha, beta, or gamma?)

A

alpha

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5
Q

does strep pneumoniae have a capsule?

if yes, what is its functional purpose?

A

yes, it protects it from phagocytes

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6
Q

is strep pneumoniae bile soluble?

A

yes

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7
Q

where is strep pneumoniae soluble?

A

in bile

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8
Q

what is sensitive (inhibits growth) to strep pneumoniae?

A

optochin

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9
Q

is strep. pneumoniae catalase + or -?

A

it is negative

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10
Q

what else is catalase negative?

A

enteroccoci

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11
Q

what helps detect the polysaccharide capsule of strep pneumoniae?

A

quellung reaction

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12
Q

what does strep pneumoniae have to damage cells in the body?

A

Pneumolysin

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13
Q

when vaccinating against strep pneumoniae, what bacterial part is the vaccine targeting?

A

the polysaccharide capsule

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14
Q

what 3 tests can be done to differentiate strep pneumoniae from strep viridans?

A

Bile soluble

Optochin sensitive

Positive quellung reaction

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15
Q

what helps protect strep pneumoniae in the body?

A

IgA protease

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16
Q

what is pneumolysin?

A

It is a cytotoxin that binds to host cell membranes and goes to the pores

17
Q

what is pneumolysin going to do to cells?

What cells are affected?

A
  • it will destroy host cells, especially:
  • Ciliated epithelial cells
  • Phagocytic cells

and

  • Suppresses phagocytic cell oxidative burst
18
Q

what diseases will strep pneumoniae cause?

A

Pneumonia

Meningitis

Otitis media

Sinusitis

19
Q

what other bacteria can cause the same diseases as strep pneumoniae?

A

haemophilus influenza

20
Q

what is the most common cause of Community-acquired lobar pneumonia?

A

strep pneumoniae

21
Q

what symptoms can be seen in Community-acquired lobar pneumonia?

A
  • shaking chills, high fever
  • Productive cough with blood-tinged sputum * (“rusty sputum”)
22
Q

what patients are at high risk of serious infection with Community-acquired lobar pneumonia?

A

elderly

asplenic

23
Q

where do you find strep pneumoniae?

A

in upper resp. tract

24
Q

how does strep pneumoniae spread?

A

through respiratory droplets

25
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)
26
what is the most common cause of adult meningitis?
strep pneumoniae
27
what symptoms can be seen in adult strep pneumoniae?
High fever Nuchal rigidity Photophobia Nausea, vomiting
28
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
29
what is one of the most common cause of sinusitis and middle ear infection?
strep pneumoniae
30
what predisposes to strep pneumoniae leading to sinusitis and otitis media?
a previous infection with the common cold
31
what is the mechanism of resistance used by strep pneumoniae?
alteration of PBP's
32
30-40% of strep pnumoniae is resistant to what drug?
penicillin
33
serious strep penumoniae infection can be treated with what drug?
Vancomycin + ceftriaxone
34
what drug is used in children with strep pneumoniae caused sinusitis and otitis media?
erythromycin
35
what prevention to strep pneumoniae exists for higher risk patients?
vaccination
36
the vaccine for strep pneumoniae uses what from the bacteria?
the capsule
37