Shared Flashcard Set

Details

Lab Tests for Streptococcaceae (Week 1)
N/a
60
Microbiology
Undergraduate 3
03/29/2015

Additional Microbiology Flashcards

 


 

Cards

Term
Streptococcaceae are catalse
Definition
Negative
Term
Micrococcaceae are catalse
Definition
Positive
Term
Streptococcaceae are gram what? What shape?
Definition
Gram-pos cocci in chains
Term
Micrococcaceae are gram what? Shape?
Definition
Gram-pos cocci in clusters.
Term
Bacitracin susceptibility (Taxo A) for Streptococcaceae
Definition
Any zone of inhibition is sensitive. Helpful to identify group A Beta-hemolytic Strep.
Term
Latex agglutination test for Streptococcaceae
Definition
Used to identify group A Beta-hemolytic Strep. Based on the group-specific carbohydrate antigen from the cell wall.
Place colonies on reaction card and rock and roll. Pos=agglutination
Term
PYR test (Pyrrolidonlyarylamidase test)
Definition
Presumptive test for both Group A Strep and Enterococcus spp.
Reagent A to paper disk and put colonies onto the disk. Incubate and then add reagent B. Pink= pos
Term
CAMP test
Definition
Group B strep produce CAMP (Christie, Atkins, Munch-Peterson) factor that acts synergistically with the Beta toxin produced by STA to produce more potent hemolysis.
Term
Method of CAMP test
Definition
Innoculate BAP with a center streak of STA. Inoculate the unknown organism and controls perpendicular to the line of STA. Observe for arrowhead hemolysis = pos
Term
Hippurate hydrolysis
Definition
Group B Strep are able to hydrolyze hippuric acid to its components, glycine and benzoic acid.
Term
Method of hippurate hydrolysis
Definition
Inoculate broth containing sodium hippurate with organism and incubate overnight at 35 degrees Celsius. 2 methods. Method A detects presence of benzoic acid Precipitate of ferric chloride last for more than 10 mins= pos. Method B detects presence of free glycine. Ninhydrin added. Deep blue/purple color = Pos
Term
Bile esculine test
Definition
Used for the identification of Enterococcus spp. and Group D Strep. Inoculate bile esculin with organism and incubate. Black color = Pos
Term
Salt tolerance test
Definition
Helps differentiate Enterococcus spp. from Group D Inoculate organism into a TSB containing 6.5% NaCl. Incubate and observe for growth. Growth= Pos.
Term
Which spp will be positive for the Salt tolerance test Enterococcus spp. or Group D Strep?
Definition
Enterococcus spp.
Term
Susceptibility to optochin (Taxo P disc)
Definition
Based on the fact that S. pneumoniae is senstive to optochin (Ethyl hydrocupreine hypochloride)
Term
Method for optochin susceptibility test
Definition
Streak BAP for isolation with organism. Place P disc in between the first and second quadrants. Incubate in Co2 and measure zone size. Sensitive >/= 14mm. Resistant is less than 14mm
Term
Strep. pneumoniae prefers what growth environment
Definition
Co2
Term
Bile solubility test
Definition
Bile salts dissolve colonies of S. pneumoniae (autolysins) Reagent = 10% sodium.
Term
Bile solubility test method
Definition
Place on drop of bile reagent on an isolated colony.Incubate media side down Pos= colony disappears. Neg= colony remains intact.
Term
Which organism is soluble in the bile solubility test?
Definition
Strep. pneumoniae, which is sensitive to the P-disk.
Term
Quellung Test
Definition
Serologic test for the detection of s. pneumoniae. No longer in use.
Term
Pneumoslide Test
Definition
Latex test for the detection of s. pneumoniae. Used on either isolated colonies or organisms grown in broth
Term
Catalse test used to differ between?
Definition
Used to differentiate between micrococcaceae and streptococcacea families.
Micrococacceae are pos
Streptococacceae are neg
Term
Catalase test explanation
Definition
In the presence of the enzyme catalse, hydrogen peroxide is broken down into water and oxygen gas.
Place h2O2 on a slide and emulsify a colony in it
Term
What can cause false positives in the catalse test?
Definition
Wire loops and blood cells from BAP
Overreading the results
Term
Glucose fermentation is used to differentiate between what?
Definition
Staphylococcus spp. and Micrococcus spp. of the Micrococacceae family
Term
Explanation of glucose fermentation
Definition
Organsisms can utilize glucose by three mechanisms: oxidation, fermentation or notat all (nonsaccharolytic)
Term
Media for glucose fermentation
Definition
OF media which is a semi-solid media cotaining a low concentration of peptones and a high conc of glucose
Term
Method of glucose fermentation
Definition
Inoculate 2 tubes of media with organism. Cover one with oil overlay. Indicator is bomthymol blue. Acid results( organisms that fermented the glucose)= yellow. Alkaline results= blue/green color
Term
Fermenters
Definition
Use the glucose in both tubes, producing a yellow color
Term
Oxidizers
Definition
Only use the glucose i the tube open to air which will be yellow. Tube with oil will remain blue (due to the absence of oxygen)
Term
Nonsaccharolytic organisms
Definition
Both tubes will be blue-green because the glucose was not used
Term
Coagulase Test
Definition
Fibrinogen(in serum) in the presence of coagulase will agglutinate to form a fibrin clot. Reagent used is EDTA rabbit plasma. Staph aureus is coag pos. Other staph are coag neg.
Term
Coagulase slide test procedure
Definition
Test for bound coagulase. 1 drop of sterile water in two circles drawn on a glass slide. Place on colony into each of the circles. Add a drop of EDTA plasma to one and mix.
Term
Coagulase tube test
Definition
Test for free coagulase. Drop pure colony into 0.5ml rabbit plasma and incubate. After 4 hours if still neg, take out and incubate at room temp for 18 hours.
Term
Staphaurex latex test
Definition
Latex particles coated with IgG bind to protein A and clumping factor produced by Staph. aureus. Visible clumping with clear backgorund= STA. No clumping with milky background= other staph
Term
Staphaurex latex test procedure
Definition
Add one drop reagent to circle on card. Use applicator stick to put a few colonies in reagent. Rotate card for 2 mins. (Nonspecific end binds to STA)
Term
DNase test
Definition
STA produces DNase which hydrolyzes nucleic acids. Positive= break down of DNA in media, a pink halo forms around well (STA) Negative= Media remains blue (STN)
Term
DNase Test procedure
Definition
Hydrolysis of nucleic acids via STA is detected by placing a well into media and filling the well with a heavy inoculum. Incubate and read results
Term
Novobiocin Susceptibility (Diagnostic Test)
Definition
Only 3 Staph spp. are novobiocin resistant. Only Staph. saprophyticus is clinically significant. Reagent used in the test are Novobiocin disk, BAP and 0.5 McFarland standard
Term
Novobiocin Susceptibility method
Definition
Make a 0.5 McFarland suspension of organisms (1.0-1.5 x 10^8 organisms/ml suspension)
Streak BAP, drop disc in center of plate, incubate, read results
Term
Results of a Novobiocin Susceptibility test
Definition
Zone of < or = to 12mm is resistant to novobiocin (S. saprophyticus)
Zone of > or = to 16mm is susceptible or sensitive to novobiocin (Other staph)
Term
Mannitol Salt Agar
Definition
High concentration of salt selects for halophiles like Staphylococcus spp. STA can ferment the mannitol as well, while other staph cannot
Term
Reagents involved in mannitol salt agar
Definition
Peptones, beef extract
7.5% Nacl
Mannitol (Fermentable carb)
Phenol red indicator
Term
Mannitol salt agar procedure and results
Definition
Inoculate mannitol salt agar with organism. If the media turns yellow under the colonies it is acidic and pos (indicative of STA). If the media remains pink/red it is alkaline (indicative of STN)
Term
Differentiation of micrococcus spp and staphylococcus spp.
Definition
Glucose utilization
Bacitracin susceptibility (Taxo A disc)
Furazolidone suscpetibility
Term
Bacitracin susceptibility (Taxo A disc) test procedure
Definition
Prepare a 0.5 McFarland suspension of organism. Streak a lawn on BAP
Drop disc in center of plate incubate.
Read results
Term
Bacitracin susceptibility (Taxo A disc) test
Definition
Used to differentiate between micrococcus spp. and staphylococcus spp. Zone of > or = to 10mm is sensitive or susceptible to bacitracin (Micrococcus spp.) Zone < or = to 10mm is bacitracin resistant (Staphylococcus spp.)
Term
Furazolidone susceptibility test procedure
Definition
Use same procedure as Bacitracin except use a 100ug disc of furazolidone
Term
Furazolidone susceptibility test
Definition
Used to distinguish Micrococcus spp. from Staphylococcus spp. No zone (<6mm) resistant to furazolidone (Micrococcus spp.) Zone > or = 15mm is susceptible or sensitive to furazolidone (Staphylococcus spp.)
Term
Staphylococcus aureus causes
Definition
Petigo
Food poisoning
Scalded skin syndrome
Carbuncles
Term
Streptococcus pyogenes causes
Definition
Acute pharyngitis (strep throat)
Scarlett Fever
Skin infections
Term
Staphylococcus saprophyticus
Definition
Clinically significant as an etiologic agent of urinary tract infections in women of child bearing age
Term
Streptococcus pyogenes (Group A beta hemolytic strep)
Definition
Pharyngitis
Yellow/white exudate on tonsils
Impetigo
Term
Streptococcus agalactiae (Group B strep)
Definition
Normal flora of the genitourinary tract
Cause of neonatal sepsis and meningitis
Wound and burn infections
Term
Group D non-Enterococcus
Definition
Normal flora of the GIT
Pathogen in UTI's, abdominal and wound infections
Term
Streptococcus pneumoniae
Definition
Pneumonia
Meningitis
Otitis media
Term
Viridans streptococci
Definition
NF or oropharynx, nasopharynx and skin
Subacute bacterial endicarditis
Seen in patients with underlying heart problems
Term
Enterococcus spp.
Definition
NF of the GIT
Cause nosocomial UTI's
Abdominal wounds
Septicemia
Term
Streptococcus milleri group
Definition
NF of the oropharynx and nasopharynx, GIT and vagina
Cause SBE, pulmonary head and neck infections, oral and abdominal abscesses
Supporting users have an ad free experience!