Term
| Streptococcaceae are catalse |
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Definition
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Term
| Micrococcaceae are catalse |
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Definition
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Term
| Streptococcaceae are gram what? What shape? |
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Definition
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Term
| Micrococcaceae are gram what? Shape? |
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Definition
| Gram-pos cocci in clusters. |
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Term
| Bacitracin susceptibility (Taxo A) for Streptococcaceae |
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Definition
| Any zone of inhibition is sensitive. Helpful to identify group A Beta-hemolytic Strep. |
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Term
| Latex agglutination test for Streptococcaceae |
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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 |
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Term
| PYR test (Pyrrolidonlyarylamidase test) |
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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 |
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Term
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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. |
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Term
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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 |
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Term
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Definition
| Group B Strep are able to hydrolyze hippuric acid to its components, glycine and benzoic acid. |
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Term
| Method of hippurate hydrolysis |
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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 |
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Term
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Definition
| Used for the identification of Enterococcus spp. and Group D Strep. Inoculate bile esculin with organism and incubate. Black color = Pos |
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Term
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Definition
| Helps differentiate Enterococcus spp. from Group D Inoculate organism into a TSB containing 6.5% NaCl. Incubate and observe for growth. Growth= Pos. |
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Term
| Which spp will be positive for the Salt tolerance test Enterococcus spp. or Group D Strep? |
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Definition
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Term
| Susceptibility to optochin (Taxo P disc) |
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Definition
| Based on the fact that S. pneumoniae is senstive to optochin (Ethyl hydrocupreine hypochloride) |
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Term
| Method for optochin susceptibility test |
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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 |
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Term
| Strep. pneumoniae prefers what growth environment |
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Definition
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Term
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Definition
| Bile salts dissolve colonies of S. pneumoniae (autolysins) Reagent = 10% sodium. |
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Term
| Bile solubility test method |
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Definition
| Place on drop of bile reagent on an isolated colony.Incubate media side down Pos= colony disappears. Neg= colony remains intact. |
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Term
| Which organism is soluble in the bile solubility test? |
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Definition
| Strep. pneumoniae, which is sensitive to the P-disk. |
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Term
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Definition
| Serologic test for the detection of s. pneumoniae. No longer in use. |
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Term
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Definition
| Latex test for the detection of s. pneumoniae. Used on either isolated colonies or organisms grown in broth |
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Term
| Catalse test used to differ between? |
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Definition
Used to differentiate between micrococcaceae and streptococcacea families.
Micrococacceae are pos
Streptococacceae are neg |
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Term
| Catalase test explanation |
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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 |
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Term
| What can cause false positives in the catalse test? |
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Definition
Wire loops and blood cells from BAP
Overreading the results |
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Term
| Glucose fermentation is used to differentiate between what? |
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Definition
| Staphylococcus spp. and Micrococcus spp. of the Micrococacceae family |
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Term
| Explanation of glucose fermentation |
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Definition
| Organsisms can utilize glucose by three mechanisms: oxidation, fermentation or notat all (nonsaccharolytic) |
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Term
| Media for glucose fermentation |
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Definition
| OF media which is a semi-solid media cotaining a low concentration of peptones and a high conc of glucose |
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Term
| Method of glucose fermentation |
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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 |
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Term
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Definition
| Use the glucose in both tubes, producing a yellow color |
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Term
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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) |
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Term
| Nonsaccharolytic organisms |
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Definition
| Both tubes will be blue-green because the glucose was not used |
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Term
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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. |
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Term
| Coagulase slide test procedure |
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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. |
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Term
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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. |
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Term
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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 |
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Term
| Staphaurex latex test procedure |
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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) |
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Term
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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) |
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Term
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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 |
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Term
| Novobiocin Susceptibility (Diagnostic Test) |
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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 |
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Term
| Novobiocin Susceptibility method |
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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 |
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Term
| Results of a Novobiocin Susceptibility test |
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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) |
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Term
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Definition
| High concentration of salt selects for halophiles like Staphylococcus spp. STA can ferment the mannitol as well, while other staph cannot |
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Term
| Reagents involved in mannitol salt agar |
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Definition
Peptones, beef extract
7.5% Nacl
Mannitol (Fermentable carb)
Phenol red indicator |
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Term
| Mannitol salt agar procedure and results |
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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) |
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Term
| Differentiation of micrococcus spp and staphylococcus spp. |
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Definition
Glucose utilization
Bacitracin susceptibility (Taxo A disc)
Furazolidone suscpetibility |
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Term
| Bacitracin susceptibility (Taxo A disc) test procedure |
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Definition
Prepare a 0.5 McFarland suspension of organism. Streak a lawn on BAP
Drop disc in center of plate incubate.
Read results |
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Term
| Bacitracin susceptibility (Taxo A disc) test |
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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.) |
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Term
| Furazolidone susceptibility test procedure |
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Definition
| Use same procedure as Bacitracin except use a 100ug disc of furazolidone |
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Term
| Furazolidone susceptibility test |
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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.) |
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Term
| Staphylococcus aureus causes |
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Definition
Petigo
Food poisoning
Scalded skin syndrome
Carbuncles |
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Term
| Streptococcus pyogenes causes |
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Definition
Acute pharyngitis (strep throat)
Scarlett Fever
Skin infections |
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Term
| Staphylococcus saprophyticus |
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Definition
| Clinically significant as an etiologic agent of urinary tract infections in women of child bearing age |
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Term
| Streptococcus pyogenes (Group A beta hemolytic strep) |
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Definition
Pharyngitis
Yellow/white exudate on tonsils
Impetigo |
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Term
| Streptococcus agalactiae (Group B strep) |
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Definition
Normal flora of the genitourinary tract
Cause of neonatal sepsis and meningitis
Wound and burn infections |
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Term
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Definition
Normal flora of the GIT
Pathogen in UTI's, abdominal and wound infections |
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Term
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Definition
Pneumonia
Meningitis
Otitis media |
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Term
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Definition
NF or oropharynx, nasopharynx and skin
Subacute bacterial endicarditis
Seen in patients with underlying heart problems |
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Term
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Definition
NF of the GIT
Cause nosocomial UTI's
Abdominal wounds
Septicemia |
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Term
| Streptococcus milleri group |
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Definition
NF of the oropharynx and nasopharynx, GIT and vagina
Cause SBE, pulmonary head and neck infections, oral and abdominal abscesses |
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