Lab Flashcards
(98 cards)
1
Q
secondary dye for endospore stain?
A
safranin
2
Q
what is the decolorizer in the endospore stain?
A
water
3
Q
what color is the vegetative cell in endospore stain
A
pink/red
4
Q
what color are gram positive bacteria on gram stain?
A
purple
5
Q
what color are gram negative bacteria on gram stain?
A
pink/red
6
Q
bacteria in cluster arrengement called
A
staph
7
Q
what shape is described as a sphere?
A
coccus
8
Q
Disc that controls amount of light going through the stage on microscope?
A
diaphragm
9
Q
part of the microscope that holds the objective lenses (can be turned)
A
nosepiece
10
Q
lens in the eyepiece is called ___
A
ocular lens, has 10X magnification
11
Q
Staphylococcus aureus and Staphylococcus epidermidis are best distinguished by which test
A
coagulase test
12
Q
Which agar would best distinguish Proteus from Salmonella?
A
urea agar
13
Q
Where will the strict anaerobe grow in thioglycolate broth?
A
only at the bottom
14
Q
Which fastidious pathogen (digestive tract) requires a special agar and incubation at 42˚C w/ 5-6% O2 & 3-10% CO2?
A
Campylobacter jejuni
15
Q
E. coli grows what color colonies on MacConkey agar?
A
pink
16
Q
T/F: Enterococcus faecalis is a Gram-negative chain of spheres that turns Bile Esculin agar black.
A
False
17
Q
In the Kirby Bauer test, the antibiotics were placed where ?
A
over the lawn of bacteria
18
Q
cytology def, histology def
A
study of cells, study of tissues
19
Q
Pathology def
A
study of disease
20
Q
Four streps of Gram stain
A
- Primary staining with crystal violet
- Fixation with Gram’s iodine (mordant)
- Decolorization with ethanol
- Secondary staining with safranin
21
Q
Blood Agar def, fn
A
enriched media to differentiate organisms based on hemolytic activity
- beta hemolysis: clearing around colonies due to complete blood cell hemolysis
- alpha hemolysis: green/brown around colonies media (partial hemolysis of cells)
- gamma hemolysis: no reaction in surrounding media
22
Q
Thioglycollate Broth
A
Sodium thioglycollate is a reducing agent (consumes oxygen), produces a range of oxygen concentration along the depth of the broth
to determine aerobe vs anaerobe vs obligate or facultative anaerobes
23
Q
Tryptic Soy Agar (TSA)
A
General media for many organisms (has no factors), often used for growth
Confirms Campylobacter jejuni by means of motility
24
Q
Beta hemolysis (describe media)
A
clearing around colonies due to complete destruction of red blood cells (ex: Strep pyogenes)
25
Alpha hemolysis (describe media)
greening around colonies due to change in hemoglobin on RBC (ex: Strep viridans)
26
Gamma reaction (describe media)
no change in blood around colonies (ex: Staph epidirmidis)
27
differential media is defined as one that...
has change in agar color
28
Sabouraud Dextrose Agar (SDA)
for isolating yeast and fungi
has chloramphenical and gentamicin=inhibit bacterial growth, clyclohexidine inhibit saprophytic fungals
29
Mueller Hinton Agar
standardized disk diffusion for ABX sensitivity testing with Kirby Bauer method.
30
SXT blood agar
isolate beta hemolytic streptococci (esp fro throat culture)
31
Lowenstein Jensen agar
isolation of Mycobacterium species.
| Has malachite green dye to inhibit most bacterial growth.
32
MacConkey agar
isolates Gram negative rods, differentiating lactose fermenting bacteria.
(bile salts inhibit gram + growth)
qualitative media
33
Chocolate agar
culture Neisseria and Hemophilus, contains factor X and factor V
34
XLD agar xylose lysine desoxycholate
for Gram negative enteric rods. Desoxycholate which inhibits gram + bacteria.
(Xylose is a carbohydrate source)
35
HE (Hektoen Enteric) Agar
for Gram negative enteric bacteria.
| Bile salts inhibt Gram + growth
36
Bile Esculin Azine Agar
isolate and ID Enterococcus faecalis (esculin +), turns indicator black
(indicator is ammonium citrate)
sodium azide inhibits Gram neg
37
Bile Esculin Azine Agar with Vancomycin
for Vancomycin resistant enterococci
38
GN enrichment broth
selective for Gram Negative (GN) bacteria, ex: Shigella, Salmonella.
Desoxycholate and citrate inhibit Gram +
39
Sorbitol MacConkey Agar
lactose is replaced by sorbitol. Most strains of E. coli ferment sorbitol to produce acid.
except E. coli O157:H7 (cannot ferment sorbitol) this raises the pH fo the media allow for differentiation of O157:H7
40
Campylobacter (CAMPY) Agar
allows Campylobacter species to grow, inhibits fungi and Enterobacteriaceae
41
Yersinia Selective Agar
used in qualitative procedures to isolate Yersinia enterocolitica.
Mannitol fermentaiton=bull's eye colony formation, clear with a red center.
42
Triple Sugar Iron (TSI) Agar
for Gram negative enteric rods, based on abilty to ferment glucose and lactose or sucrose for detection of H2S production.
43
Urea Agar (or broth)
differentiation of bacteria based on urease activity.
| Bacteria use urea=ammonia is formed (basic)=pehnol turns pink/red
44
Simmons Citrate Agar
Gram negative enteric rods using citrate as carbon source.
| citrate used=alkaline environment turns indicator blue
45
BiGGY (Nickerson) Agar
for Candida species
| Reduce bismuth sulfide=> brown/black pigment
46
Modified Thayer Martin Chocolate Agar
Qualitative media to isolate Neisseria gonorrheae and Neisseria meningitidis. Has factors X and V.
Colistin inhibit gram neg bacteria
vancomycin inhibits gram pos bateria
nystatin suppresses growth of Candida albicans
47
DNase Agar
to detect DNase activity in bacteria. Bacteria that produce DNase alter the DNA in the media right next to their growth.
48
Mannitol Salt Agar
for isolating Staphylococcus, (7.5% NaCl inhibits any other growth)
Staph aureus ferments mannitol= acidic environment=> phenol red indicator> yellow
49
Rodac Plate
to determine efficiency of sanitation containers, equipment, and surfaces. contains TSA
50
Litmus Milk Broth
To maintain lactic acid bacteria, to determine the action of bacteria on milk. Differentiating them based on lactose fermentation, coagulation of casein, gas production, reduction of litmus.
51
Bacitracin disc (A disc) Test
presuptive ID of Strep pyogenes. Low concentrations of bacitracin to inhibit growth.
(disk usually contains 0.04 units bacitracin)
52
Optochin disc (P disc) Test
presuptive test to ID Strep pneumonia, it is not resistant and a zone of inhibition will develop around disk (usually 14mm in diameter)
53
CAMP test
to ID Streptococcus agalactiae (Group B strep). weak beta hemolysis of Group B strep will synergistically combines with beta hemolysis from Staph aureus=> forms arrowhead shape of strong hemolysis, characteristic of CAMP
54
Oxidase test
To differentiate between Pseudomon (oxidase +) families and Enterobacter families (oxidase - )
oxidase positive will turn blue/dark purple
55
Indole test
Tryptone broth to determine indole production by Enterobacters. Bacteria take tryptophan and make indole.
Red= + (indole produced)
yellow= negative
56
Methyl Red test
for glucose fermentation, add methyl red to tube, if organism uses the sugar in the broth=acidic conditions.
If yellow=no acidic product negative
Red= stable acidic product (glu fermenter)
57
Agglutination
Clumpting. Cells containing antigens to a given antibody will react when mixed with the solution. agglutination usually indicative of antibody presence.
58
Germ tube (test)
a germ tube is a filamentous extension of a yeast cell (arm like growth) up to 3-4 times the length of the cell.
common in Candida albicans.
59
Catalase test
ID organisms that produce catalase enzyme, it convers hydrogen peroxide to water and oxygen gas.
differentiating staphylococci (catalase +) and streptococci, enterococci (catalase neg)
60
Coagulase test
if an enzyme produced exoenzyme coagulase (causes fibrin of blood to clot)
differentiating Staphylococcus aureus and Staphylococcus epidermidis
61
Streptococcus pyogenes flow chart
```
gram positive spheres in chain
⬇︎
pinpoint colonies, Beta hemolysis on BAP
⬇︎
inhibition by bacitracin disc
```
62
Streptococcus agalactiae flow chart
gram positive spheres in chain
⬇︎
beta hemolysis on BAP, grey/white colonies
⬇︎
Id by + CAMP test (characteristic arrowhead)
63
Streptocossus pneumoniae flow chart
gram positive spheres usually in pairs
⬇︎
alpha hemolylitic on BAP, facultative anaerobe
⬇︎
zone of inhibition with Optochin disc (P disc)
64
Klebsiella pneumoniae flow chart
```
gram negative rod, non-motile
⬇︎
pink mucoid colonies on MacConkey agar
⬇︎
lactose fermenting, facultative anaerobe
```
65
Haemophilus influenzae flow chart
gram negative coccobacilli (oval-ish)
⬇︎
capnophillic (thrive on high CO2), fastidious: needs factor V and X present on CAP, BAP lacks V
66
Haemophilus parainfluenzae flow chart
```
gram neg coccobacilli
⬇︎
campnophillic, requires only factor V
⬇︎
satellites on agar with no factors like TSA (this distinguishes from H. influenzae)
```
67
The four steps of Endospore stain
1. primary stain with hot Malachite Green
2. Rinse w/ DI water
3. secondary stain with Safranin
4. Rinse w/ DI water
68
Steps of Acid Fast stain
1. Primary stain w/ hot Carbol Fuchsin
2. Rinse w/ DI water
3. Decolorize with Acid-alcohol (HCl and ethanol)
4. Secondary stain: Methylene Blue
69
Mycobacterium tuberculosis flow chart
```
rod-shaped non-motile
⬇︎
Acid-fast stain (M tuberculosis=red, everything else=blue)
⬇︎
grown on Lowenstein-Jensen agar
```
70
Escherichia Coli flow chart
```
gram negative rod
⬇︎
Gamma rxn on BAP, lactose fermenter pink on MacConkey
⬇︎
facultative anaerobe
```
no growth on bile esculin or mannitol salt
71
Enterobacter sp flow chart
```
gram neg, rod shaped
⬇︎
-grey on BAP
-pink mucoid on MacConkey (lactose fermenter)
-yellow on XLD
-orange on HE
```
72
Proteus sp. flow chart
gram neg rods
⬇︎
urease producer, H2S producer= black precipitate
⬇︎
NOT lactose fermenter= colorless on MacConkey
⬇︎
-red w black center on XLD
-green w black center on HE
⬇︎
"proteus swarming' waves on agar as species travel across surface
73
Shigella sp. flow chart
```
gram neg rods
⬇︎
NOT lactose fermenter-colorless on McConkey
-red on XLD
-Green on HE
```
74
Salmonella sp flow chart
```
gram neg rods
⬇︎
NOT lactose fermenter- colorless on McConkey
⬇︎
H2S producer- black precipitate
-red/black center on XLD
-green on HE
```
75
Pseudomonas sp flow chart
gram neg rods
⬇︎
-NOT lactose fermenters= colorness on MacConkey
-red on XLD
-green on HE
⬇︎
produce oxidase=> turn blue w oxidase reagent
76
Campylobacter jejuni flow chart
```
gram neg spiral rods, motile
⬇︎
CAMPY agar: incubation at 42˚C w/ 5-6% O2 & 3-10% CO2
⬇︎
TSA agar also confirms it by motility
```
77
Yersinia enterocolitica flow chart
```
gran negative rods, motile
⬇︎
Yersinia selective agar
⬇︎
bullseye colony formation: clear w red center
```
78
Neisseria gonorrheae flow chart
```
gram neg, diplococcus
⬇︎
fastidious: needs 10% CO2 on Chocolate or MTM Chocolate (factors X and V)
⬇︎
oxidase positive after incubation (blue)
```
79
Trepomena pallidum flow chart
```
spirochetes
⬇︎
don't grow on artificial media
⬇︎
ID w rapid plasma reagin test on a serum sample
```
80
Chlamydia trachomatis flow chart
```
gram neg(like) bacteria in coccus/rod shapes
⬇︎
obligate aerobe, intracell parasite
⬇︎
humans only, the major cause of STIs
```
81
Neisseria meningitidis flow chart
gram negative, coffee bean shaped diplococci
⬇︎
best grows at 35-37C (5% CO2= candle jar)
⬇︎
grows on BAP ( unpigmented, round smooth colonies) and chocolate agar (large grey/colorless colonies)
82
Staphylococcus aureus flow chart
```
gram positive cluster of spheres
⬇︎
-Beta hemolysis on BAP
-catalase +
-coagulase +
-DNase +
-ferments mannitol
⬇︎
No growth on MacConkey or Bile Esculin
```
83
Staphylococcus epidermidis flow chart
```
gram positive clusters of cocci
⬇︎
-gamma on BAP
-catalase +
⬇︎
-coagulase neg
-DNase neg
-doesn't ferment mannitol
```
84
Clostridium perfringens flow chart
```
gram positive rod (non motile), spore forming
⬇︎
requires little/no oxygen
⬇︎
toxin producing
```
85
Clostridium tetani flow chart
gram positive rods, obligate anaerobe
⬇︎
two endotoxins produced-- enter CNS=damage
DTap, Tdap vaccines
86
what is the primary dye for the endospore stain?
Malachite Green
87
Describe H2S test
Hydrogen sulfide binds to iron salt in the medium
+ = black color (from iron sulfide)
- = any other color
88
Describe urea test
bacteria convert urea-> ammonia
yellow media to start
No color change= Negative
pink=positive
89
describe the shape: Coccus
round
90
describe the shape: bacillus
rod
91
describe the shape: Spirillum
spiral rods
92
describe the shape: Spirochete
tight spiral rods
93
diplo-
two
94
strepto-
chains
95
staphylo-
clumps
96
Explain cell wall of gram negative
well wall w/ 2 membranes and a THIN layer of peptidoglycan.
| lose crystal violet when retaining counterstain Safranin
97
Explain cell wall of gram positive
cell wall with 1 membrane and a THICK layer of peptidoglycan.
(retain crystal violet-iodine complex)
98
Bile solubility test
differentiate Streptococcus pneumoniae (+, soluble) from alpha hemolytic streptococci (-, insoluble)
