EXAM A Flashcards
Enterococcus has ________________ resistance
vancomycin
(VRE)
What differentiates S. pneumoniae from viridans group?
-Optochin sensitive/resistance was NOT an answer choice. That is usually the differentiating factor, but it wasn’t a choice.
-Viridans group and S. pneumoniae = alpha hemolytic
Bacitracin:
is Micrococci susceptible or resistant?
susceptible
Bacitracin:
is Staphylococci susceptible or resistant?
Susceptible (check this one)
Sapro can be differentiated from other species of Staphylococcus through antibiotic testing as it is resistant to the antibiotic __________.
novobiocin
Novobiocin resistant staph?
Saprophyticus
S. Aureus is susceptible
What is the latex agglutination test is for?
-protein A and bound coagulase
-possess coagulase and/or protein A, particularly Staphylococcus aureus
how to differentiate between strep pyo and strep agalac?
Bacitracin (A-disk)
-Differentiating S. pyogenes from other β-hemolytic Streptococcus spp.
Pyogenes is ___________ to bacitracin
susceptible
- any zone of inhibition of growth is considered a positive test result
Pyogenes is PYR _____ and strep agalac is PYR _______.
positive,
negative
CAMP/HHT positive or negative?
-aga: ___________
-pyo: ___________
positive
negative
“disk test” is used for the different streps
sus for pneumo?
sus for pyo?
P disk (Optochin disk)
A disk (Bacitracin disk)
Lancefield classification:
Pyo?
A
Lancefield classification:
aga
B
Lancefield classification:
dys?
C? G?
Lancefield classification:
entero/non-entero?
D
what organisms are DNAse (+)?
Aureus and moraxella
True or false:
Strep agalactiae is hippurate negative
FALSE, hippurate positive!***
Is neisseria gram positive or negative?
what is the morphology?
gram negative diplococci
Know the difference between gonorrhea and meningitidis based on the sugars
-gon =
-men =
gon: just glucose
men: glucose and maltose
Know what tests are usually done to identify the different neisseria
-Gram stain: Gram negative diplococci
-Oxidase test: positive result
-Antigen detection/serology testing
What is used for definitive diagnosis of different neisseria?
nucleic acid amplification testing (NAAT), Agar dilution susceptibility testing
Which neisseria is found in joint fluid?
N. Gon
How to identify Gardenella Vaginalis?
Analysis of vaginal discharge, pH, and scent
Gardenella Vaginalis:
gram stain…
gram-negative coccobacilli
Gardenella Vaginalis:
“______ cells” can be seen when doing wet mount.
clue
Gardenella Vaginalis:
What is positive?
glucose/maltose fermentation, Hippurate Hydrolysis
Gardenella Vaginalis:
What is negative?
urease, nitrate reduction, mannitol fermentation, xylose fermentation
Know what media is used for G. vaginalis
Human blood tween
Know what the Loeffler medium is used for?
Used for the growth and isolation of the Corynebacterium spp.
Know that ____ is characteristic of Erysipelothrix on TSI media***
H2S
Erysipelothrix is gram _________
positive
What kind of infection is Erysipeolthrix associated with?
skin infections from fish
brucella is a _____________ agent.
bioterrorism
Could you work with burcella on the bench if you clean with bleach?
NO. bioterrorism agent due to their ability to undergo aerosolization
If a brucella culture shows no growth at 5 days, how long can you keep letting it grow?
21 days is the longest
best way to incubate campylobacter?
-42*c microaerophilic environment
-Media: Campy-BA, Charcoal-based selective medium (CSM), Campylobacter agar base blood-free (CCDA)
How to quickly identify B. anthraxis from other bacillus spp
-B. anthracis is typically non-motile and displays gamma hemolysis as well as a susceptibility to penicillin and gamma phages
-Can be ruled out through the use of penicillin resistance testing since it is susceptible, motility testing since it is non-motile, and inoculation of blood agar since it is non-hemolytic
Is bacillus a frequent contaminant?
They rarely cause disease in the immunocompetent and are more frequently isolated as a culture contaminant
Can bacillus grows on MAC?
No, typically Bacillus species cannot grow. MacConkey agar is selective for gram-negative and inhibits the grown of gram positive bacteria
-bacillus are gram-positive and do not ferment lactose so they will not grow well on MacConkey agar
Differentiate between staph, strep, neisseria:
Gram positive chains with catalase positive will be…
staphylococci
Staph aureus and intermedius are both coagulase and catalase ______________
positive
N. gonorrheae -> ____________ fermenter
glucose
N. meningitidis -> ____________ fermenter
Glucose & maltose
Generally…
Strep -> Catalase ____________
Coagulase __________
neg
neg
N. Lactamica -> ________________ fermenter
Glucose, Maltose, and Lactose
Generally….
Staph -> Catalase and Coagulase ____________
positive ?
Micrococcus is _____________ sensitive.
bacitracin
Mircococcus is catalase ________.
positive
Micrococcus is coagulase ___________.
negative
Micrococcus is oxidase ___________.
positive
What causes Whooping cough?
Bordetella pertussis or Bordetella parapertussis that is found in the mouth, nose and throat of an infected person
What media is used for Bordetella pertussis?
charcoal-blood agar (REGAN-LOWE medium) or Bordet-Gengou agar (primary isolation)
Haemophilus:
Gram ___________ coccobacillus
negative
Haemophilus:
motile or non motile?
non motile
Haemophilus is normal flora of…
upper respiratory tract
Which haemophilus has Beta hemolysis of horse blood?
H. haemolyticus
What Haemophilus requires X factor (hemin)?
H. influenza , H. ducreyi, and H. heamolyticus
What haemphilus requires V factor (NAD)?
H. influenza, H. haemolyticus, and H. parainfluenzae
Which hemophilus has the ability to convert ALA to Protoporphyrin?
H. parainfluenzea, and H. aphrophilus
What agars do heamophilus grown on?
all will grow on chocolate and (10% CO2) agar because it supplies both X and V factors
-also grow on horse or rabbit blood agar.
What agar will haemphilus NOT grow on?
Sheep Blood agar because SBA contains NADase, which inactivates NAD
What is the phenomenon known as “satelliting”?
When grown in media containing blood, staphylococcus aureus produces NAD (V factor) as a byproduct. It also hemolyzes blood cells, releasing hemin (factor X)
As a result Haemophilus is able to grow on sheep blood agar close to the colonies of S. aureus.
What bacteria are bile esculin positive?
Entero and Listeria
factor V is released from __________ and aids for growth of H.influence!
staph
which brucella is pos on brucella dye tolerance media for BOTH thionin and fuchin?
Brucella melitensis
gardnerella uses ________ media AND Hippurate Hydrolysis pos
tween
What is the morphology of garnerella?
gram positive bacilli
garnernell is catalase…
positive
Does garnerella produce H2S?
No
Lactobacillus can be confused with garnerella. the main thing is lactobacillus is normal flora and found in _________ and ________.
palisades
chains
which media to use for C. diphtheriae ID
Loeffler and Cystine Tellurite Blood Agar (CBTA)
Micrococcus is catalase _________.
positive
Micrococcus is coagulase _________.
negative
Mircococcus is _________ sensitive.
Bacitracin
Mircooccus is oxidase _______.
positive
How does mircooccus utilize sugars in the O/F test?
oxidatively or not at all
O/F test:
mircococcus oxidatively —->
yellow w/ open tube & green w/ closed tube
O/F test:
oxidizer –>
(utilizes sugar not at all) will be green / green
