Module 10 Flashcards
who discovered a “transforming factor” transferred between streptococcus pneumoniae
Fredrick Griffith
What do S. aureus & A. pyogenes have in common?
a - they both produce coagulase
b - they both secrete catalase
c - both can cause toxic shock syndrome
d - both have a protein G that binds antibodies
e - all of these are shared properties
c - both cause toxic shock syndrome
S, pneumoniae is frequently isolated as ___
normal flora from upper respiratory tract of healthy individuals
s. pneumoniae is the most frequent cause of ___ in infants and children
otitis media
s. pneumoniae is a common cause of ___ and ___ in all ages
bacteremia, meningitis
___ and ___ streps show partial or no hemolysis
mitis & mutans
what is incomplete lysis of RBCs with a zone of greening or darkening under and around colonies
alpha hemolysis
s. pneumoniae is a ___ strep of normal flora but is also an important ___
mitis, pathogen
what does s. pneumoniae cuase
- pneumonia
- meningitis
- otitis media
- sinusitis
what is the microscopic morphology of s. pneumoniae
gram + diplococci
DOES NOT FORM CHAINS
s. pneumoniae are potentially ___, although they can live without issue in the ___
invasive, URT
what is the main disease caused by s. pneumoniae
pneumococcal pneumonia
what are the symptoms of pneumococcal pneumonia
- rapid onset of shaking, chills, fever, cough with copious “rusty” sputum
- x-ray shows heavy consolidation
As with both S. oralis and s. aureua, there is potential for pneumococcal pneumonia to lead to ___ and then ___
- bacteremia
- meningitis or endocarditis or septic arthritis
how does meningitis occur
bacterial spread from pleura via lymphatics to bloodstream to meninges
all isolates of s. pneumoniae should be tested for resistance to __ due to its increasing emergence
penicillin
what are the virulence factors of s. pneumoniae
- capsule
- exotosins
what is the major virulence factor of s. pneumoniae
capsule
what is the function of the bacterial capsule
- anti-phagocytic
- blocks bacterial surface antigens
non-encapsulated rough strains of s. pneumoniae are typically seen in the healthy __
URT
what is the exotoxin virulence factor of s. pneumoniae
pneumolysin
pneumolysin is only observed _____
anaerobically
what is the oxygen-labile hemolysin that cross-reacts with streptolysin O and is hemolytic and kills phagocytes
pneumolysin
what is the enzyme virulence factor of s. pneumoniae
IgA1 protease
what is the function of IgA1 protease
aids in colonization of mucosal surfaces through cleavage of sIgA
how many common isolates is the old vaccine PPV purified from
23
how many common isolates is the heptavalent conjugate vaccine PCV7 purified from
7
what is a characteristic of the heptavalent conjugate vaccine PCV7
conjugated to a protein
the old vaccine PPV works well in ___ but has no response in ___
adults, children <2 years old
how many common isolates is the PCV13 conjugate vaccine purified from
13
Which is correct in terms of the relative pathogenic potential of s. pneumoniae and s. oralis?
a - all of these
b - s. oralis can cause heart valve infections
c - s. pneumoniae can cause heart valve infections
d -s. pneumoniae is able to cause many diseases
a - all of these
what is the simplest way to definitively identify streptococcus pneumoniae causing characteristic disease?
a - distinct cell shape and arrangement
b - gram + coccus
c - catalase negative
d - coagulase negative Gram + coccus
a - distinct cell shape & arrangement
diplococci
the pneumococcus is alpha hemolytic unless
a - grown on defined lactose media
b - grown to stationary phase
c - deprived of nutrients
d - grown anaerobically
d - grown anaerobically
which pair of infectious diseases caused by s. pneumoniae are caused as frequently by other bacteria?
a - endocarditis and arthritis
b - meningitis and ear infection
c - bacteremia and impetigo
d - all of these
d - all of these
