Biochemical Tests Flashcards
(105 cards)
1
Q
PEA: name, type, what
A
- Phenylethyl Alcohol
- Selective
- Selective for gram (-) by interfering with DNA synth. in gram (+) bacteria
2
Q
Indicator for PEA?
A
None
3
Q
(+) PEA test
A
Growth = gram (-) bacteria
4
Q
EMB: name, type, what
A
- Eosin Methylene Blue
- Selective and Differential
- Selects for gram (-)
- Differential for coliforms
5
Q
(+) EMB test (pink)
A
Gram (-) bacteria with coliforms
6
Q
(+) EMB test (green)
A
Gram (-) bacteria E. coli with coliforms
7
Q
(+) EMB test (white/colorless)
A
Gram (-), no coliforms
8
Q
(-) EMB test
A
No growth, gram (+) bacteria
9
Q
MSA: name, type, what
A
- Mannitol Salt Agar
- Selective and Differential
- Selects for Staphylococcus and Micrococcus species
- Differentiates for the ability to ferment mannitol
10
Q
EMB indicator?
A
Eosin and Methylene Blue
11
Q
MSA indicator?
A
Phenol Red
12
Q
(+) MSA test (pink/red)
A
Non-pathogenic Staphylococcus or Micrococcus
13
Q
(+) MSA test (yellow)
A
Pathogenic Staphylococcus or Micrococcus
14
Q
Starch plate: type, what
A
- Differential
- tests for production of amylase
15
Q
Starch plate indicator?
A
None
16
Q
How does the the starch plate work?
A
The iodine and starch create a charge-transfer complex that makes the starch really dark. A clearing around the bacteria means the starch was broken down into glucose so there is nothing for iodine to bind to.
17
Q
(+) Starch Plate Test
A
Clearing present after pouring iodine –> Amylase was produced
18
Q
(-) Starch Plate Test
A
No clearing after pouring the iodine –> no Amylase was produced
19
Q
OF Glucose: name, type, what
A
- Oxidative-Fermentative Glucose
- Differential
- Deferential for if bacteria can break down glucose through fermentation or oxidation
20
Q
OF Glucose indicator?
A
Bromothymol Blue (pH dependent)
- glucose catabolized = acid release –> pH decreases
21
Q
(+) OF Glucose Test for fermentation
A
Anaerobic tube = yellow
Aerobic tube = yellow
22
Q
(+) OF Glucose Test for oxidation
A
Anaerobic tube = remains green
Aerobic tube = yellow at the top
23
Q
(-) OF Glucose Test
A
Anaerobic tube = remains green
Aerobic tube = teal/blue, indicates ammonia byproduct from catabolized peptones, can’t use glucose
24
Q
Fermentation Tubes: type, what
A
- Differential
- Differentiates if bacteria can catabolize a certain carbohydrate
25
Fermentation tube indicator?
Phenol Red; if fermented then acid is released and the pH goes down
26
Red fermentation tube...
(-), non-fermenter
27
Yellow fermentation tube...
(+), fermenter
28
Yellow fermentation tube with gas...
(+), true fermenter
29
Gelatin Hydrolysis: type, what
- Differential
- Determines if the bacteria can catabolize gelatin by using gelatinase
30
Gelatin Hydrolysis indicator?
None
31
(+) Gelatin hydrolysis Test
Gelatin liquifies
32
(-) Gelatin hydrolysis Test
Gelatin remains solid
33
Urease Test: type, what
- Differential
- determines if a bacteria produces urease
34
Urease Test indicator?
Phenol Red, if urease is produced, ammonia will be released and the pH increases
35
(+) Urease Test
Pink
36
(-) Urease Test
Remains the same color (orange)
37
Phenylalanine Slant: type, what, *special*
- Differential
- determines if bacteria can deaminate phenylalanine
* needs ferric acid to test results
38
Phenylalanine Slant indicator?
None
39
By-product of phenylalanine slant?
The removal of the amine group creates ammonia and creates phenylpyruvic acid as a byproduct
40
(+) Phenylalanine Slant
Green: ferric chloride reacted with the phenylpyruvic acid
41
(-) Phenylalanine Slant
Yellow: no phenylpyruvic acid was produced
42
MIO Deep: name, type, what, *special*
- Motility Indole Ornithine
- Differential
- Tests for motility, production of tryptophanase, and putrescine
*needs Kovac's reagent to see results*
43
MIO Deep indicator?
Bromocresol purple; if glucose is fermented acid is released and pH decreases
44
Indole production...
from tryptophanase that turns tryptophan to indole
45
Ornithine production...
Decarboxylation of ornithine produces putrescine
46
MIO after Kovac's = Pink/Red ring
Indole is present and the test is (+)
47
MIO after Kovac's = no ring present
No indole is present, test is (-)
48
MIO Deep (+) for Ornithine
Deep remains purple or turns grey = putrescine was produced
49
MIO Deep (-) for Ornithine
Deep turns yellow --> glucose was fermented --> acid was produced
50
Peptone Iron Deep: type, what
- Differential
- Determines if bacteria can liberate sulfur from cystene
51
Peptone Iron Deep indicator?
None
52
(+) Peptone Iron Deep
Black precipitate = ferrous sulfide
53
(-) Peptone Iron Deep
Media appears unchanged
54
Oxidase Test: type, what, *special*
- Differential
- determines if cytochrome C is produced
*grow bacteria on NA plate then use oxidase strip*
55
Oxidase test indicator?
None
56
(+) Oxidase Test
Blue or Purple after a few minutes
57
(-) Oxidase Test
Does not change in color
58
Catalase Test: type, what, *special*
- Differential
- Determines if the bacteria can produce catalase
*must use hydrogen peroxide on growth*
59
Catalase Test indicator?
None
60
(+) Catalase Test
Bubbles are produced = catalase breaking down hydrogen peroxide into H2O and O2
61
Nitrate Broth Test: type, what, *special*
- Differential
- determines if bacteria can produce nitrate reductase
*must use reagents A and B to see results, possibly need zinc powder*
62
Nitrate Broth Test indicator?
None
63
(+) Nitrate Reduction Test after A and B only
Red/pink = nitrites formed
64
(-) Nitrate Reduction Test after A and B only
Yellow = no reduced nitrites
65
(+) Nitrate Reduction Test after A, B, and zinc
Yellow = reduced to gas
66
(-) Nitrate Reduction Test after A, B, and zinc
Red/pink = does not reduce from the original form (nitrates)
67
Mueller Hinton: type, what, *special*
- Enrichment
- used to test response to antibiotics
- contains starch which inhibits exotoxins from interfering with the AB discs.
68
Mueller Hinton indicator?
None
69
Zone of inhibition:
Clearing around the AB disc that should be measured and compared to a chart to see if the bacteria is susceptible or resistant to the AB disc.
70
Sheep Blood Agar: type, what, *special*
- Enrichment and Differential
- Determines the hemolytic capabilities of the microbe
*needs to be in a microaerophilic environment*
71
Sheep Blood Agar: Alpha, Beta, and Gamma
Alpha: cloudy green zone, partial destruction, non-pathogenic
Beta: clear zone, complete destruction, pathogenic
Gamma: no zone, no destruction, non-pathogenic
72
Sabouraud Dextrose Agar: type, what, *special*
- Selective
- Selective for mold, yeast, and some filamentous bacteria
* slightly acidic (pH ~5.6) *
73
Sheep Blood Agar Test indicator?
None
74
Sabouraud Dextrose Agar indicator?
None
75
(+) Sabouraud Dextrose Agar Test
Growth!
76
Tomato Juice Agar: type, what, *special*
- Enrichment and Selective
- Selects for Lactobacillus
* needs to be incubated in an anaerobic environment *
77
Tomato Juice Agar indicator?
None
78
(+) Tomato Juice Agar Test
Growth! indicates Lactobacillus
79
MacConkey Agar: type, what, *special*
- Selective and Differential
- Selective for gram (-)
- Differential for coliforms (lactose fermenting vs non)
- contains bile salts and crystal violet to inhibit gram (+) bacteria
80
MacConkey Agar indicator:
Neutral Red; lactose fermented --> acid released --> pH decreases
81
MacConkey Agar Pink Growth
Gram (-) enterics, able to ferment lactose
82
MacConkey Agar White Growth:
Gram (-) enterics, unable to ferment lactose
83
MacConkey Agar no growth:
Bacteria was gram (+)
84
Equation of catabolism of hydrogen peroxide:
2H2O2 ---catalase----> 2H2O + O2
85
Equation of respiration:
C6H12O6 + 6O2 --> 6CO2 + 6H2O + 38 ATP
86
Gram (-) bacteria:
Stains red/pink, LPS layer, harder to kill w/ AB
87
Gram (+) bacteria:
Stains purple and creates the crystal violet-iodine complex because of a thick peptidoglycan layer
88
Semmelweis:
Medical students doing autopsies and then delivering babies. He noticed midwives didn't have as high rates of sepsis because they washed their hands.
89
Sterile:
Devoid of any microbes
90
Decontamination:
The attempt to remove microbes off of you but they will come right back
91
Autoclave:
121 degrees C, 15 minutes, at 15 psi
92
Robert Kock:
wanted solid media but gelatin melted. Angelina Hesse suggested he use agar because it does not melt at room temp.
93
Facultative Anaerobes:
can use O2 and ferment, the highest concentration of bacteria will be at the top
94
Aerotolerant anaerobes:
Cannot use O2 but it does not harm them, found diffusely in broth
95
What makes endospores?
Genuses Clostridium and Bacillus
96
Scanning lens:
4x
97
Low Dry:
10x
98
High Dry:
40x
99
Oil lens:
100x
100
CFU formula:
number of colonies / (DF) x (amount plated)
101
Dilution Factor formula:
amount transferred / (amt. transferred) x (amt. already in tube)
102
1 ml =
1000 ul (microliters)
103
What do you call bacillus:
PILL SHAPED
104
Phases of bacteria growth:
1. Lag phase: growing and dying at same rate
2. Log phase: exponential growth (best)
3. Stationary phase: growing and dying at same rate
4. Death phase: dying faster than growing
105
How many amino acids are there?
20 amino acids, 9 are essential
