Microbiology General Questions
What induces TNF and IL-1 on gram + and gram - cell membranes? -
answerLipoteichoic acid and Lipid A (part of LPS), respectively
Major surface Ag for gram - - answerO polysaccharide
Where are beta-lactamases contained? - answerPeriplasmic space, between the
cytoplasmic membrane and outer membrane of gram - bacteria
Most capsules are made of __________, except for B. anthracis, which has a capsule
made of __________ - answerPolysaccharide; D-glutamate (a polypeptide capsule)
3 things to which spores are resistant - answerDehydration, heat, chemicals
Composition of spores - answerKeratin-like coat made of dipicolinic acid and
peptidoglycan
3 components of endotoxin/LPS - answerPolysaccharide O Ag, core (inner & outer),
and Lipid A; Lipid A anchors the complex in the outer membrane of gram - bacteria and
is responsible for inducing TNF/IL-1-mediated septic shock
Only medically-relevant gram - coccus - answerNeisseria
Branching/filamentous gram + bacteria - answerActinomyces, Nocardia
Pleomorphic gram - bacteria - answerRickettsiae, Chlamydiae
Spirochetes are gram __ - answer-
Mycoplasma have no cell wall, but their cell membrane does contain _______ -
answerSterols
Mycobacteria cell walls contain __________ and have a high _______ content -
answerMycolic acid; lipid
Why doesn't Treponema gram stain? - answerToo thin to be visualized
Why doesn't Mycobacteria gram stain? - answerHigh lipid content in cell wall (instead,
carbolfuchsin + acid-fast stain)
, Why doesn't Mycoplasma gram stain? - answerNo cell wall
Why doesn't Legionella gram stain? - answerPrimarily intracellular (instead, silver stain)
Why doesn't Rickettsia gram stain? - answerIntracellular parasite
Why doesn't Chlamydia gram stain? - answerIntracellular parasite and lacks muramic
acid in the cell wall
Giemsa stains these bugs - answerChlamydia, Borrelia, Rickettsiae, Trypanosomes,
Plasmodium (intracellular stuff)
Periodic acid-Schiff stains these 2 things; what disease is it used to diagnose? -
answerGlycogen and mucopolysaccharides; it is used to diagnose Whipple disease,
caused by Tropheryma whipplei
Ziehl-Neelsen stains these bugs - answerAcid-fast organisms = Mycobacteria and
Nocardia
India ink or mucicarmine stain this bug - answerCryptococcus neoformans
Silver stains these bugs - answerFungi, Legionella, Helicobacter pylori
What do we grow on chocolate agar with factors V (NAD+) and X (hematin)? - answerH.
influenzae
What do we grow on blood agar with S. aureus? - answerH. influenzae
What do we grow on Bordet-Gengou (potato) agar? - answerB. pertussis
What do we grow on Tellurite agar or Loffler medium? - answerC. diphtheriae
What do we grow on Lowenstein-Jensen agar? - answerM. tuberculosis
What do we grow on Eaton agar with cholesterol? - answerM. pneumoniae
What do we grow on MacConkey agar? - answerGram - bugs; if they turn it pink, they're
lactose fermenters (like E. coli)
What do we grow on charcoal yeast extract agar (with cysteine and iron)? -
answerLegionella
What do we grow on Sabouraud agar? - answerFungi
What induces TNF and IL-1 on gram + and gram - cell membranes? -
answerLipoteichoic acid and Lipid A (part of LPS), respectively
Major surface Ag for gram - - answerO polysaccharide
Where are beta-lactamases contained? - answerPeriplasmic space, between the
cytoplasmic membrane and outer membrane of gram - bacteria
Most capsules are made of __________, except for B. anthracis, which has a capsule
made of __________ - answerPolysaccharide; D-glutamate (a polypeptide capsule)
3 things to which spores are resistant - answerDehydration, heat, chemicals
Composition of spores - answerKeratin-like coat made of dipicolinic acid and
peptidoglycan
3 components of endotoxin/LPS - answerPolysaccharide O Ag, core (inner & outer),
and Lipid A; Lipid A anchors the complex in the outer membrane of gram - bacteria and
is responsible for inducing TNF/IL-1-mediated septic shock
Only medically-relevant gram - coccus - answerNeisseria
Branching/filamentous gram + bacteria - answerActinomyces, Nocardia
Pleomorphic gram - bacteria - answerRickettsiae, Chlamydiae
Spirochetes are gram __ - answer-
Mycoplasma have no cell wall, but their cell membrane does contain _______ -
answerSterols
Mycobacteria cell walls contain __________ and have a high _______ content -
answerMycolic acid; lipid
Why doesn't Treponema gram stain? - answerToo thin to be visualized
Why doesn't Mycobacteria gram stain? - answerHigh lipid content in cell wall (instead,
carbolfuchsin + acid-fast stain)
, Why doesn't Mycoplasma gram stain? - answerNo cell wall
Why doesn't Legionella gram stain? - answerPrimarily intracellular (instead, silver stain)
Why doesn't Rickettsia gram stain? - answerIntracellular parasite
Why doesn't Chlamydia gram stain? - answerIntracellular parasite and lacks muramic
acid in the cell wall
Giemsa stains these bugs - answerChlamydia, Borrelia, Rickettsiae, Trypanosomes,
Plasmodium (intracellular stuff)
Periodic acid-Schiff stains these 2 things; what disease is it used to diagnose? -
answerGlycogen and mucopolysaccharides; it is used to diagnose Whipple disease,
caused by Tropheryma whipplei
Ziehl-Neelsen stains these bugs - answerAcid-fast organisms = Mycobacteria and
Nocardia
India ink or mucicarmine stain this bug - answerCryptococcus neoformans
Silver stains these bugs - answerFungi, Legionella, Helicobacter pylori
What do we grow on chocolate agar with factors V (NAD+) and X (hematin)? - answerH.
influenzae
What do we grow on blood agar with S. aureus? - answerH. influenzae
What do we grow on Bordet-Gengou (potato) agar? - answerB. pertussis
What do we grow on Tellurite agar or Loffler medium? - answerC. diphtheriae
What do we grow on Lowenstein-Jensen agar? - answerM. tuberculosis
What do we grow on Eaton agar with cholesterol? - answerM. pneumoniae
What do we grow on MacConkey agar? - answerGram - bugs; if they turn it pink, they're
lactose fermenters (like E. coli)
What do we grow on charcoal yeast extract agar (with cysteine and iron)? -
answerLegionella
What do we grow on Sabouraud agar? - answerFungi
