Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
66 Cards in this Set
- Front
- Back
What organisms are identified and why?
|
Left = s. pyogenes
Right = GBS Bacitracin sensitivity: This is used to test for s. pyogenes versus group B strep. Both are beta hemolytic. S. pyogenes is bacitracin sensitive meaning that it will not grow around the b (A) disk. GBS will grow right up to the disk. |
|
Bug and disease?
MAC colorless Lactose (-) HEK = blue green w/o black dots Lactose (-) G(-) rod |
Shigella sonnei
Bloody Diarrhea (bacillary dysentery) |
|
What test is used to differentiate between Strep and staph species?
|
Catalase Test
Postitive = bubbles upon addition of H2O2 to bacteria. Staph spp. Is positive. Negative = Strep |
|
Bug and disease?
-BAP = NO growth - CAP = Growth - Thayer Martin Gram (-) Diplococci Oxidase (+) CTA=glc (+), maltose (-) |
Neisseria gonorrhoeae
Urethritis/Cervicitis |
|
Describe chocolate agar plate?
|
This is enriched of blood agar essential for some organisms
like Neisseria and haemophilus. Haemophilus needs X and V factor to grow. Because this media is not selective, Neisseria must also be put through the cytochrome oxidase and CTA sugar test. Haemophilus should be test on another media with the addition of X and V factor. |
|
Bug and disease?
Gram (-) Rod - MAC= Colorless (lactose (-)) - HEK = Blue W/ black dots (lactose (-)) - SMAC = Pink (sorbitol (+)) Facultative |
Salmonella enteridis
Bloody diarrhea |
|
Bug?
SMAC=Colorless (sorbitol -) MAC=Pink (lactose+) Gram – rod Oxidase – Lactose Fermenter |
E. coli O157
(EHEC) |
|
You want to identify your unknown for Pseudomonas aeruginosa.
Name and describe test. |
OF Dextrose:
This aids in the identification of organisms oxidizing dextrose in either an aerobic or fermentative way. This is used to identify pseudomonas aerugionosa. Tue from green -> yellow with growth. One tube is open and one has mineral oil over it. Pseudomonas will only grow on the one without the mineral oil. |
|
Bug and Disease?
Bile Esculin = Growth (black colonies) NaCl = Growth (cloudy) Gram (+) Cocci Catalase (-) |
Enterococcus faecalis (Group D)
UTI |
|
Definitive lab test for Strep. agalactiae (Group B)?
|
CAMP Test = “Arrowhead”
|
|
Bug?
Gram (-) coccobacillus - BAP = NO Growth - CAP = Growth |
Haemophilus influenzae
|
|
Compare and contrast N. gonorrhoeae and N. meningitides?
|
CAP = Growth - N. meningococcus=glc(+),maltose(+)
Thayer Martin - N. gonococcus=glc (+),maltose (-) Gram (-) Diplococci |
|
Bug?
Gram (+) Cocci clusters Catalase (+) Coagulase (+) Novobiocin Sensitive NaCl Growth |
Staph. aureus
|
|
Bug?
- MAC = Pink (lactose (+)) - SMAC = Pink (sorbitol (+)) |
Other E. Coli NOT EHEC
|
|
Bug?
Gram (+) Cocci Catalase (-) -Hemolytic Bacitracin Sensitive (A) CAMP Test -NO Arrowhead |
Strep. pyogenes (Group A)
|
|
Which plate is selective for Gram + bugs?
|
CNA
|
|
Bug and disease?
- MAC = Pink (lactose (+)) - SMAC = Pink (sorbitol (+)) |
E. Coli
UTI |
|
Which plate is selective and differential for isolating certain
pathogenic members of enterobacteraceae while inhibiting the more numerous members? Which bugs will grow on this plate? |
Hektoen enteric agar
Salmonella, shigella, e coli and Proteus |
|
Bug?
MAC = Growth OF Dextrose = Aerobe Gram (-) Rod Oxidase (+) Obligate Aerobe |
Pseudomonas aeruginosa
|
|
Bug and Disease?
Gram (+) Cocci clusters Catalase (+) Coagulase (-) Facultative Novobiocin Resistant **key |
Staph. saprophyticus
|
|
Bug and name of plate?
|
Salmon to orange colonies: lactose fermenters -> e. coli
Hektoen enteric agar |
|
Describe test and relevant bugs. If a tube of glucose was added, how would the results change?
|
CTA sugar Test
This is used to determine Neiserria spp. It is sucrose, glucose and maltose and a positive YELLOW reaction indicates fermentation. Negative is red. N. gonococcus = glc (+), maltose (-) N. meningococcus = glc (+), maltose (+) |
|
What organisms are identified and why?
|
Right=Staph epidermidis
Left=Staph saprophyticus Novobicin Resistance: This test is used to speciate Staph. S. saprophyticus is the only resistant staph. Meaning that S. epidermidis is susceptible. |
|
The growth around XV is indicative of which bug?
|
X, V, and XV factor on TSA for haemophilus
|
|
What organism is identified on this MAC and why?
|
E. coli is a lactose fermenter
MacConkey Agar: Used for the isolation of lactose fermenting gram – rods. The bile salts inhibit all gram + except enterococcus. Pink or read indicating lactose fermentation colorless indicate non lactose fermenters. |
|
Possible bugs?
|
Cytochrome Oxidase test:
Neisseria, vibrio. and pseudomonas are oxidase positive. |
|
ID this organism on MAC plate.
|
Shigella and Salmonella do not ferment lactose
|
|
What bugs are identified and why?
|
Bile Esculin Agar:
This contains bile as an inhibitor and esculin as a substrate. This presumptively identifies Group D strep and Listeria. Group D strep shows a positive reaction meaning black colonies surrounded by brownish black halos. Listeria shows minute black colonies. |
|
Left tube is positive for which 2 possible bugs?
Right? |
Salt tolerance for enterococcus
S. aureus will also grow so it is important to do a catalase test. Right tube is (-) = Streptococcus |
|
What bugs and describe plate?
|
TCBS
Selective medium for vibrio cholera. Other enterics will grow, but they can be easily dif. Btwn vibrio by color. Vibrio cholera – yellow Vibrio parahemolyticus – green e. coli – transluscent proteus – yellow pseudomonas – blue |
|
Bug?
|
SIM tube:
Listeria exhibits mushroom shaped growth at room temp. |
|
Interpret
|
Virus agglutination
A – agglutination, B -weak agglutination, C- no agglutination |
|
Interpret this test.
|
This is an API from a stool culture of E. coli.
First half-yellow or clear = (-) Second half-yellow = (+) Add up results and look up in book for organism |
|
Bug?
|
N. gonorrhoeae ferments only glucose.
Gonorhoeae=Glucose Meningitidis=Maltose AND Glucose |
|
Which plate uses sorbital instead of lactose as the sugar. If the strain is the 0157:H7 bad strain it will not grow. Everything else should grow the same. Meaning gram neg enterics such as shigella, salmonella, and e coli non- 0157:H7?
|
sMac
Salmonella is a sorbitol fermenter. (pictured above) |
|
Describe test and bug?
|
Coagulase test:
Used to test between staph species. S. aureus is the only coagulase positive |
|
Bug and plate?
|
non lactose fermenters -> shigella
Hektoen enteric agar |
|
Describe this test including the 3 bugs involved.
|
A=GBS (Strep agalactiae)
B=GAS (Strep pyogenes) Center=Staph aureus CAMP Test: This provides identification for GBS. GBS produces a Camp factor that enhances the beta hemolysis of S. aureus. Because of this a large “arrow head” of hemolysis will show a positive reaction |
|
Describe this plate and which bugs are associated.
|
Blood Agar - Basically everything grows on blood agar except Haemophilus spp. Neisseria spp. are require the blood products to be lysed, not whole.
When you look at a BAP you want to see if the growth shows one of 3 things: - Beta -hemolysis: a clear/yellowish zone of complete lysis beneath colonies. This indicates that whatever was growing here has a lysine such as SLO that will cause the blood cells to be lysed. S. pyogenes and GBS - Alpha hemolytic: a greenish less distinct zone of partial hemolysis. S. pneumoniae, viridans strep, and group D enterococcus - Gamma hemolytic: a lack of hemolysis. |
|
Which plate here is selective for gram + organisms. It specifically inhibits the growth of most facultative and aerobic gram -. It also will show the hemolytic pattern of Strep spp.?
|
CNA agar
CNA plate (only G+ grows) S. aureus on the left and e. coli, on the right not growing |
|
Bugs and name of plate?
|
Black centers: H2S production -> proteus (green) and salmonella (blue)
Hektoen enteric agar |
|
Bacitracin Sensitivity (A disk)
disease / possible organism? |
(+)/sensitive – Group A Strep
(-)/resistant – Group B Strep |
|
disease / possible organism?
BE (bile esculin agar) (+) = black colonies |
(+) – Enterococcus spp
(+) – Streptococcus spp |
|
disease / possible organism?
BAP (blood agar) ->CO2 |
HEMOLYSIS:
α – S pneumo β – S pyogenes (Gp A), S agalactiae (Gp B) γ – (non-hemolytic) Enterococcus spp. |
|
disease / possible organism?
CAMP Test BAP w/ S aureus |
(+) – Group B Strep -> “arrowhead” hemolysis
|
|
disease / possible organism?
Catalase Test 3% H2O2 -> bubbles |
(+) Staph
(-) Strep |
|
disease / possible organism?
CAP (chocolate agar)/Thayer Martin -> CO2 |
(+)/growth – Neisseria spp, Haemophilus spp.
|
|
disease / possible organism?
Coagulase Test rabbit plasma (citrated if fast coag test) |
(+) S aureus
(-) all other Staph |
|
disease / possible organism?
CNA -> CO2 |
Gram (+) organisms ONLY
(If incubated anaerobically, Bacteroides will grow) |
|
disease / possible organism?
CTA Test (carbohydrate degradation) -> incubate O2 (+) = yellow |
Neisseria differentiation
N gonorrhoeae – gluc (+) N meningitidis – gluc (+) AND malt (+) |
|
disease / possible organism?
Latex Aggluttination (+) = grainy ppt (-) = milky |
Check serum antibodies against viruses
- CMV - VZV - Rubella |
|
disease / possible organism?
Gram Stain (+) = blue (-) = red |
(colony + water droplet, dry, heat fix)
1. Crystal Violet Soln 2. Iodine Soln 3. Acetone-Alcohol decolorization 4. Safranin Soln G(+) = blue G(-) = red |
|
disease / possible organism?
HEK (Hektoen agar) Colonies: - orange = lactose ferm - blue-green = lactose nonferm - black centers = H2S |
Enterobacteriaceae differentiation
E coli = lactose (+), H2S (-) <orange, no black ctr> Shigella = lactose (-),H2S (-) <green, no black ctr> Salmonella = lactose (-), H2S (+) <blue, black ctr> |
|
disease / possible organism?
MAC (Lactose) Pink = lactose ferm, gram (-) rods Clear = lactose nonferm, gram (-) rods |
E coli = lactose (+)
Shigella = lactose (-) Salmonella = lactose (-) |
|
disease / possible organism?
SMAC (Sorbitol) Pink = sorbitol ferm Clear = sorbitol nonferm |
E coli O157:H7 = sorbitol (-)
Other E coli = sorbitol (+) |
|
disease / possible organism?
Novobiocin resistance (NB disk) |
(+)/sensitive – S aureus, S epidermidis
(-)/resistant – S aprophyticus |
|
disease / possible organism?
O/F Dextrose ID Pseudomonas |
Sugar -> Acid
Oxidative fermentation only in open air tube = aerobic |
|
disease / possible organism?
Optochin Test (P disk) |
(+)/sensitve – S pneumo
|
|
disease / possible organism?
Oxidase Test (+) = blue |
Neiserria spp = (+)
Pseudomonas = (+) Vibrio spp = (+) E coli = (-) |
|
disease / possible organism?
Salt Tolerance – 6.5% NaCl broth (+) = turbidity |
(+)/turbid – Enterococcus
(-)/clear - Streptococcus |
|
disease / possible organism?
SIM Tube Motility assay – grown at rm temp |
Listeria monocytogenes
SIM: umbrella, semi-solid agar Nutrient broth: liquid |
|
disease / possible organism?
API – stool cx |
First half – yellow or clear = (-)
Second half – yellow = (+) Add up results -> look up in book for organism |
|
disease / possible organism?
TCBS |
Vibrio = yellow
E coli = clear |
|
disease / possible organism?
T soy plate: Factors X & V |
H influenzae -> satellite colony around X+V
|
|
Which plate is selective for Gram (-) bugs?
|
HEK
|
|
How can Strep. pneumoniae be determined by lab ID?
|
Gram (+) Cocci
Catalase (-) Optochin Sensitive (P) Alpha Hemolytic |