One deck to rule them all Flashcards
(117 cards)
1
Q
3 solutions for acid-fast staining
A
- carbol fuschin stain
- 3% acid alcohol
- methylene blue
2
Q
Detecting bacterial capsule (2)
A
Quellung/ neufeld reaction or capsule stain
3
Q
Solutions for capsule stain
A
India ink and carbol fuschin
4
Q
Detection of spore (4)
A
- phase contrast microscope
- zhiel neelsen
- moeller stain
- gram stain (negative stain)
5
Q
What is the flagella stain?
A
tannic acid and aluminium potasium phosphate
6
Q
What does Neisser stain detect?
A
presence of polar / volutin / babes-ernst granules in C; dyphteriae
7
Q
Differenciating - selective culture media?
A
Eosin-methylene blue, only gram negative bacteria grow, differenciates w/ lactose fermentation
8
Q
Volume sample blood culture adults
A
20-30mL / blood culture
9
Q
What is streaking?
A
A technique to isolate a pure strain from a single species of bacteria
10
Q
Aerobic bacteria (2 ex)
A
- p. aeruginosa
- m. tuberculosis
11
Q
Parameters of culture of aerobes
A
37°C, 70-80% humidity, 02, 1 atm
12
Q
Parameters of culture of microaerophiles
A
5%O2, 10% CO2, 85% N2
13
Q
What does hippurate positive mean?
A
It means that it hydroxylyses sodium hippurate
14
Q
What does CAMP test positive mean?
A
Increased zone of hemolysis when put with s. aureus
15
Q
How long do you keep each solution on the slide for gram staining?
A
Crystal violet : 2 minutes
Iodine : 1 minute
Ethanol : until it’s no longer purple
Safranin : 1 minute
16
Q
Neisser 1 solution
A
Methylene blue, glacial acetate, 96% ethanol, distilled water
17
Q
Neisser 2 solution
A
10% crystal violet in 96% ethanol, 96% ethanol, distilled water
18
Q
Chrysoidin solution
A
1% chrysoidin aqueous solution in distilled water
19
Q
Result of neisser staining
A
Bacterium : yellow, granules : purple
20
Q
How do we differenciate acid-fast bacteria?
A
Acid-fast bacteria are resistant to decolorizer (acid) due to high amount of lipoidal material in their cell wall.
21
Q
How long do we keep each solution on the slide for the acid fast?
A
Carbol fuschin : 5 minutes (after heat)
Acid alcohol : 5 minutes
Methylene blue : 2 minutes
22
Q
What type of objective is used for acid fast stain?
A
1000x oil immersion objective
23
Q
Size of microorganisms and virus
A
Bacteria : 0.1-50 microM
Fungi, protozoa : 5-100 microM
Viruses : 20-400 nM
24
Q
What is waterhouse friedrichen syndrome?
A
hemorrhage of the adrenals
25
What is a bacterial lawn?
sheet of bacteria that covers an agar plate used to determine antibiotic resistance of that species or for bacteriophage typing
26
Example of a selective medium (2)
- manitol salt agar
| - chocolate agar with vancomycin for h. influenzae
27
Example of a differenciation medium
eosin methylene blue agar
28
2 microaerophilic bacteria
campylobacters, neisserias
29
Microaerophilic agar for C.Jejuni
skirrow campylobacter selective agar
30
What is anaerostate
physical method of anaerobic incubation, with N2 and CO2 instead of room air
31
chemical methods for anaerobic culture of bacteria
- broth
- thioglycolate bouillon
- gaspack jar
32
IC bacterias grown on animals
- t. pallidum grown on rabbit testis
| - m. leprae on the feet of a mouse or armadillo
33
examples of obligate IC bacteria
- rickettsia
- coxiella
- chlamydia trachomatitis
- mycobacterium leprae
34
What is a biofilm?
A collection of surface associated microbial cells that is enclosed in an ECM
35
2 gram positive rods
- corynebacterium
| - listeria
36
How to diferenciate gram negative rods
lactose fermentation and oxidase test
37
What are the obligate structures of bacteria? (5)
- cell wall
- plasma membrane
- cytoplasm
- nucleoid
- periplasmic space
38
Non-essential structures of bacteria (6)
- capsule
- plasmid
- spore
- fimbriae
- pili
- flagella
39
How are plasmids transferred?
binary fission or conjugation
40
Spore formation process (4)
1. bacteria divides asymmetrically
2. fore spore is engulfed by mother cell
3. Spore is dehydrated to mature
4. Endospore is released when destruction of mother cell
41
Arrangements of flagella (3)
- monotrichous (p. aeruginosa)
- amphitrichous
- peritrichous (e. coli)
42
What do streptococci ferment?
glucose
43
Detection of biofilm (3)
- tissue culture plate
- tube method
- congo red staining
44
optimum growth media for campilobacter jejuni
- 42 degrees
- skirrow media
- microaerophilic
45
optimum growth media for listeria monocytogenes
- 4 degrees
| - facultative anaerobic
46
bacteria with positive urease test
klebsiella, proteus
47
enterobacteriacecae family (4)
escherichia, klebsiella, salmonella, shigella
48
Serological reactions using precipitation (5)
- Disk precipitation
- Flocculation
- Elek test
- Radial immunodiffusion
- Electrophoresis
49
Serological reactions using agglutination (3)
1. slide agglutination
2. tube agglutination
3. co-agglutination
50
Validation of serological tests
- experiment : precision, repetability...
- incremental process
- statistical verification
- constant observation and maintenance
- reassessment of test performance for each population
51
types of allergic skin test (3)
- scratch test
- intradermal
- patch
52
3 susceptibility tests and their uses
- Tuberculin test (tb)
- Schick test (diphteria)
- Lepromin test (type of leprosy)
53
3 roles of the capsule
- major virulence factor : protects from phagocytosis
- antigenic properties (K antigen) for identification
- aids adhesion
54
Which bacteria can form spores?
Gram positive bacteria :
- bacillus (aerobic)
- clostridium (anaerobic)
55
Microaerophiles lvl of O2 + example
21% or less
| Campylobacter
56
Example of capnophile
h. influenzae
57
Enzymes needed for aerobic respiration (3)
- superoxide dismutase
- peroxidase
- catalase
58
Glucose fermenters (3)
- v cholerae
- clostridium
- streptococci
59
Mannitol fermenter
S. Aureus
60
What is the cooking method ineffective against?
tetanus, clostridium, hepatitis agents
61
Examples of antiseptics and disinfectants (7)
- alcohols
- acid bases
- quaternary ammonium compounds
- oxidizing agents
- halogens
- phenolic compounds
- aldehydes
62
3 examples of antimicrobial combinations
- TMP/SMX "cotrimoxazole"
- Amoxicillin / clavulanic acid "coamoxiclav"
- Gentamycin / vancomycin
63
TMP
trimethoprim
64
SMX
sulfamethoxazole
65
What type of drug is vancomycin?
glycopeptide
66
What type of drug is gentamycin?
aminoglycoside
67
Natures of penicillins (4)
- natural
- aminopenicillins
- penicillase resistant
- antipseudomonal
68
What is cephalosporin ineffective against?
LAME : listeria, atypical pneumonia, MRSA, enterococci
69
Beta lactam antibiotics
Penicillins, cephalosporins, carbapenems, monobactams
70
Mnemonic for names of carbapenems
Ertamerodori-imi
71
What is special with imipenem
It is given with cilastatin because it is vulnerable against dehydropeptidase in kidney
72
What is special about monobactams
- Effective against aerobic gram negative only
| - binds pbp3
73
What is bacitracin / polypeptide ab effective against?
Gram positive cocci
74
Inhibitors of 30S subunit
Aminoglycosides, tetracyclines
75
Inhibitors of 50S subunit
Amphenicol, macrolides, lincosamides, linezoid
76
Action of aminoglycosides
Inhibit initiation complex
77
Action of tetracyclines
Block tRNA from binding A site
78
Mechanism of action choramphenicol
Blocks peptidyl transferase
79
Mechanism of action of macrolides
Blocks translocation of 50S
80
Mechanism of action of lincosamides
Blocks peptide translocation
81
Detection of flagella (3)
- Flagella stain
- Swarming motility
- Native observation with high magnification
82
What do you use dark field microscopy for?
For spirochetes (borrelia, treponema, leptospira)
83
Optimum pH for cultivation of v. cholera
8-9
84
Optimum pH for cultivation of lactobacillus
5.4-6.6
85
Different cultivation temperatures
- mesophilic (30-37)
- thermophilic (over 50)
- cryophilic (under 20)
86
Composition of agar plate
2% agar + bouillon
87
Composition of blood agar
5% defibrinated sheep blood + agar
88
4 uses for animal in microbiology
- Study of intracellular bacteria
- Evaluation of sterilization process
- Testing effectiveness of drugs and chemicals
- Determination of toxin production
89
Dilution method to determine MIC/MBC (2)
- broth dilution
| - agar dilution
90
Diffusion method to determine MIC/MBC (2)
- disk diffusion
| - e-test
91
Mechanism of action of quinolones
inhibits DNA gyrase and topoisomerase IV
92
Mechanism of action of nitroimidazole
free radical production : breaks dna strands
93
Mechanism of action of rifamycin
inhibits DNA dependant RNA polymerase
94
Mechanism of action of formaldehyde (2)
- denatures proteins
| - disrupts nucleic acids
95
Mechanism of action of chlorine (2)
- denatures proteins
| - oxidizes peptide links
96
Mechanism of action of phenolics
- denatures proteins
| - inhibits permeases at high conc.
97
Mechanism of action of detergents (quaternary ammonium compounds)
Disrupts cell membrane
98
Mechanism of action of isopropyl alcohol
Denatures proteins and DNA
99
Which medium is used for urease test?
Christensen's urea agar
100
What does the indole test detect?
The ability to transform tryptophan into indole (tryptophanase)
101
3 tube agglutination tests and their use
- Widal (salmonella)
- Weil (rickettsia)
- Wright (brucella)
102
How do you detect an infection with the titer?
A fresh infection is indicated by at least 2-4x increase in the Ab titer
103
Bacteria detected using direct immunohistochemistry
Chlamydia trachomatitis
104
What are paired sera tests?
Sera drawn from patient 2-4 weeks apart are tested simultaneously
105
Possible results to tuberculin test (3)
- under 10 mm : negative
- between 10 and 20 mm : vaccinated
- over 20 mm : positive
106
What is conversion in a diagnostic test?
negative test then positive test
107
What is reversion in a diagnostic test?
positive test then negative test
108
What is fixed dose procedure?
orally administer toxin to lab animals and determine dose to produce symptoms but not death
109
What are ppm?
Mass of a chemical per unit volume of water
110
Phases of acute infection (4)
- incubation
- prodromal
- acute
- convalescence
111
Routes of transmission of infection (6) + example
- enteral (salmonella)
- inhalation (tuberculosis)
- through skin (tetanus)
- urinary (e. coli)
- sexual (syphilis)
- congenital (toxoplasma)
112
Difference between mycoplasma pneumoniae and other mycoplasms
Mycoplasma pneumoniae is obligate aerobe while the others are facultative anaerobes
113
Diseases caused by ureaplasma urealyticum (4)
- Urethritis
- Pyelonephritis
- Spontaneous abortion
- Premature birth
114
Long term complications of chlamydia
- PID (women)
| - Reactive arthritis (Reiter's syndrome)
115
Difference between enterococcus and enterobacter?
enterococcus : gram positive cocci
| enterobacter : gram negative rod
116
Toxins of bacillus anthraxis (2)
LF : lethal factor
| EF : edema factor
117
Culturing media for corynebacterium dyphteriae (2)
- tellurite medium
| - loefller's medium
