Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CMBM E2 CB > Microbiology > Flashcards

Microbiology Flashcards

1
Q

What are the major differences between prokaryotes and eukaryotes?

A 
Prokaryotes:
\+no "true" nucleus (nucleoid)
\+no paired chromosomes
\+cell wall made of peptidoglycans
\+divide by binary fission
Eukaryotes:
\+possess a "true" nucleus and nucleolus
\+nucleus surrounded by membrane
\+contain organelles
\+divide by mitosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the major difference between gram positive and gram negative bacteria?

A

Gram negative bacteria have a lipid bilayer outer membrane containing porin proteins.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are porins?

A

Proteins in outer membrane that regulate uptake of hydrophilic materials from the environment (sugars, amino acids, ions). Antibiotics often pass through porins to enter the cell.

ONLY IN GRAM-NEGATIVE BACTERIA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a bacterial capsule?

A

+outermost structure of bacteria, tightly bound to cell wall
+usually polysaccharide
+functions: inhibits phagocytosis, promotes adherence, acts as a barrier to toxic compounds (e.g. antibiotics)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are flagella?

A

Proteins extending from cell surface of some bacteria; used for motility.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are fimbriae/pili?

A

Protein extending from cell surface of some bacteria; used as attachment structures to promote sexual conjugation and adhesion to human cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are sex pili?

A

Allow binding between bacteria; form a tube through which bacterial genes can be transferred.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What codes for sex pili?

A

F plasmid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the differences between fimbriae and pili?

A 
Fimbriae:
\+sticky projections
\+adherence and attachment
\+shorter than flagella
\+hundreds per cell
\+biofilm
Pili:
\+hollow rod-like projections
\+made of pilin protein
\+longer than fimbriae, shorter than flagella
\+typically 1-2 per cell
\+sex pili mediate conjugation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the functions of flagella?

A

+locomotion
+stimulation [of antibody formation]
+adhesion [to human cells]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the structural differences between gram positive and gram negative bacteria?

A 
Positive:
\+thick (multi-layered) peptidoglycan layer
\+many teichoic acids
\+NO periplasmic space, porins, or outer membrane
\+virtually no LPS content
\+some have spores
\+only produce EXOTOXINS
\+sensitive to lysozyme
Negative:
\+thin (single-layered peptidoglycan)
\+NO teichoic acids
\+possess periplasmic space, porins, and outer membrane
\+high LPS content
\+NO spores
\+produce exotoxins AND endotoxins
\+resistant to lysozyme
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the outer membrane in bacteria?

A 
Only in gram negative bacteria
LPS embedded in outer membrane
Barrier to noxious environmental materials
Sieve for small water-soluble molecules
Adsorption site for bacteriophage
Adsorption site for sexual pili
Reservoir for proteases, enzymes, toxins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the regions of LPS?

A

Lipid A - responsible for endotoxic activity of molecule
Core - contains unusual sugar (ketodeoxyoctonate)
O-antigen - specific polysaccharide; highly variable from one species and strain to another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

In terms of LPS, what happens when gram negative bacteria lyse?

A
  1. LPS binds LPS-binding protein
  2. Bound LPS attaches to macrophage
  3. Entire complex induces transcription of cytokines
  4. Cytokines induce coagulation, inflammation, and MAC lysis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is a major structural similarity between gram positive and gram negative bacteria?

A

Both can potentially have capsules.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What kind of spore can ravage a hospital?

A

Clostridium
Obligate anaerobe
Super hard to get rid of

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What kind of bacteria have spores?

A

Only gram positive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What do spores do for bacteria?

A

Protect from heat, radiation, and chemical/enzyme attacks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Which pathogenic bacteria produce spores?

A

Bacillus

Clostridium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the starter molecule for peptidoglycan synthesis?

A

NAG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is a colony forming unit?

A

Estimate of the number of living cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is used to create divisions within bacteria?

A

Proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is an operon?

A

Two or more genes are controlled by ONE promoter –> polycistrionic mRNA
Only found in prokaryotes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the terminal electron acceptors for bacterial anaerobic respiration?

A

Metals (nitrate, sulfate, etc)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Most human pathogens are ______ an/aerobes

A

Facultative anaerobes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Describe the components of an operon.

A

Operon = encodes multiple genes, but controlled by one promoter

Operator = segment of DNA that is located adjacent to a promoter and usually binds a repressor protein

Promoter = RNA pol binds here to translate the operon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

How do bacteria become resistant to antibiotics?

A

Through genetic mutation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Why are mutations easy to see in bacteria?

A

Bacterial genome is haploid, therefor unable to mask mutations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What structural component of bacteria is the functional equivalent of most of the organelles in a eukaryotic cell?

A

The cell membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How do you clinically differentiate and ID bacteria?

A
  1. Morphology and gram stain
  2. Growth condition/abilities
  3. ID products of metabolism
  4. Simple chemical or enzymatic tests
  5. Molecular techniques (RFLP, sequencing, etc)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is ribotyping and what are the pros/cons of using it?

A

Form of sequencing bacteria. Genes that code for ribosomal RNA are cut and separated by electrophoresis. The resulting fingerprint is visualized with fluorescent probes.

Pros:
rapid
reproducible
works for a wide range of bacterial specieis

Cons:
expensive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

How do you clinically differentiate between strains of bacteria?

A

Molecular techniques are powerful, but they cannot differentiate between strains. Must use basic chemical/enzymatic tests to ID strains.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

How is transcription controlled in an operon?

A

Transcription initiation controlled by the -35 and -10 box, found in the promoter region (RNA pol binding site)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Which mechanisms produce genetic change in bacteria?

A
  1. Rapid mutation rate, rapid generation time

2. DNA acquisition from environment or other bacteria/organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is a silent mutation?

A

Base substitution in DNA that has no effect on the polypeptide produced. Can still have significant effect on gene expression due to changing mRNA stability.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is the main difference between transposons and insertion sequences?

A

Transposons can pick up and carry other genes with them (e.g. antibiotic resistance). Insertion sequences cannot.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is pathogenicity?

A

Ability of an organism to gain entry into a host’s tissues and bring about an anatomic or physiological change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is virulence?

A

Degree of pathogenicity of a parasite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What are three virulence factors?

A
  1. Structural (cell wall, capsule, pili)
  2. Biochemical (exotoxins, enzymes)
  3. Genetic (plasmids, phages)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is bacterial competence?

A

Ability of bacterium to take up naked DNA from the environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What are two examples of adherence factors?

A

Adhesins (surface projections) and biofilms (aggregate of microorganisms in which cells adhere to each other and resist clearance)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

How does Neisseria gonorrhea protect against antibodies?

A

By producing anti-IgA proteases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Which cells are the number one responders to infection?

A

Neutrophils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What are the five main mechanisms of exotoxins?

A
  1. Inhibit [protein synthesis]
  2. Hyperactivate [cellular proteins]
  3. Form [pores in cellular membranes]
  4. Interfere [with nerve transmission]
  5. Activate [T-cells nonspecifically]
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What are bactericidal antibiotics?

A

Antibiotics that target the cell wall, causing lysis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What are examples of bactericidal drugs?

A

Beta lactams
Vancomycin
Daptomycin (cell membrane only)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What are bacteriostatic antibiotics?

A

Inhibit bacterial growth and/or replication.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What are the classes of bacteriostatic antibiotics?

A

Abx that inhibit RNA synthesis
Abx that block protein synthesis
Abx that target DNA or DNA synthesis
Antimetabolite abx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Antibiotic that inhibits RNA synthesis

A

Rifamycin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Abx that block protein synthesis

A

Aminoglycosides
Macrolides
Tetracyclines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Abx that target DNA/DNA synthesis

A

Quinolones

Metronidazole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Antimetabolite abx

A

Trimethoprim-sulfamethoxazole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What are the gram positive and negative Beta Lactams?

A

Penicillins
Cephalosporins
Carbapenems
Monobactams

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What are the gram positive cocci Beta Lactams?

A

Vancomycin

Daptomycin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What are the TB drugs?

A

Isoniazid
Ethambutol
Pyrazinamide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What are the classes of penicillins?

A

Natural penicillins
Anti-staphylococcal penicillins
Aminopenicillins
Extended spectrum penicillins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What are the natural penicillins?

A

V and G

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

What are the anti-staphylococcal penicillins?

A

Nafcillin
Oxacillin
Dicloxacillin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What are the aminopenicillins?

A

Ampicillin

Amoxicillin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What are the extended spectrum penicillins?

A

Piperacillin
Ticarcillin
Carbenicillin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What are the Beta Lactamase inhibitors?

A

Clavulanic acid
Sulbactam
Tazobactam

62
Q

What is the mechanism of action for anti-staphylococcal penicillins?

A

Have large R side groups which make them resistant to Staphylococcal beta-lactamases

63
Q

Mechanism of action for aminopenicillins

A

Addition of an amino group to the R side chain –> penetration through PORINS of SOME gram negatives (especially enteric rods)

64
Q

Aminopenicillins are particularly useful for _____.

A

Enteric rods

65
Q

Mechanism of action for extended spectrum penicillins

A

Better able to penetrate GRAM NEGATIVE PORINS than aminopenicillins

66
Q

Mechanism of action for Beta Lactamase inhibitors

A

Bind beta-lactamases and act as a sponge to take up all the beta-lactamases and protect beta-lactam ring of antibiotic from being degraded

67
Q

What are natural penicillins active against?

A

Most streptococcal species (not S. pneumoniae)
Most gram positive anaerobes
Treponema pallidum (spirochete)

68
Q

Natural penicillins are ineffective against _____.

A

Aerobic and anaerobic gram negative rods

69
Q

What is the function of transpeptidases?

A

Catalyze the cross-linking of peptidoglycan residues in the bacterial cell wall

70
Q

What is the mechanism of action for Beta Lactam abx?

A

Bind transpeptidases and block this reaction, resulting in weak cell walls and bacterial lysis if bacteria are actively growing

71
Q

Aerobic gram-positive bacteria

A

Staph
Strep
Enterococci
Listeria

72
Q

Which antibiotic first became resistant to penicillin and how did it do so?

A

Staph aureus

Made Beta-Lactamase: enzyme that breaks beta-lactam ring, inactivating the antibiotic

73
Q

Which bacteria causes syphilis?

A

Treponema pallidum

74
Q

Beta-lactam ring is the important structural component of which antibiotic?

A

Penicillin

75
Q

Which bacteria are mostly resistant to penicillin?

A 
Staph aureus (always)
Strep pneumo (most of the time)
76
Q

What would you use to treat MRSA?

A

Vancomycin

CANNOT use anti-staphylococcal penicillins

77
Q

What would you use to treat MSSA?

A

Nafcillin

CAN use anti-staphylococcal penicillins

78
Q

What would you use to treat MSSE?

A

Nafcillin

CAN use anti-staphylococcal penicillins

79
Q

Methicillin resistance is due to _______.

A

Altered PBP

80
Q 
Catalase positive
Coagulase positive
Gram positive
Cocci
Clusters
A

Staph aureus

81
Q 
Catalase positive
Coagulase negative
Gram positive
Cocci
Clusters
Novobiocin sensitive
A

Staph epidermidis

82
Q 
Catalase positive
Coagulase negative
Gram positive
Cocci
Clusters
Novobiocin resistant
A

Staph saprophyticus

83
Q

Catalase negative
Gram positive
Cocci
Chains

A

Strep

84
Q

Gram positive
Lancet shaped diplococci
Alpha hemolytic
Optochin sensitive

A

Strep pneumo

85
Q

Gram positive
Cocci
Alpha hemolytic
Optochin resistant

A

Strep viridans

86
Q 
Gram positive
Cocci
Beta hemolytic
Positive cAMP test
Bacitracin resistant
A

Strep agalactiae

87
Q

Gram positive
Cocci
Non-hemolytic

A

Strep bovis

88
Q

Gram positive rods
Terminal spores
Positive for lecithinase alpha toxin

A

Clostridium perfringens

89
Q 
Gram positive
Non-spore forming
Bacilli
Actin rockets
Tumbling motility
A

Listeria monocytogenes

90
Q 
Gram positive
Branching
Bacilli
Obligate aerobe
Partially acid fast
A

Nocardia asteroides

91
Q

Gram positive
Bacilli
Spore forming
Anaerobic

A

C. Diff

92
Q

Gram positive
Cocci
Grows in 6.5%
Hydrolyzes esculin

A

Enterococcus faecelis

93
Q

Spectrum of activity for aminopenicillins

A

Same as natural penicillins, with the addition of some strains:

E. coli
Shigella
Salmonella Enterica
Borrelia burgdorferi

94
Q

Extended spectrum penicillins treat….

A

Same as natural penicillins, with the addition of:

Some strains of pseudomonas aeruginiosa

95
Q

Five types of exotoxins

A
  1. Inhibiting protein synthesis
  2. Hperactivation of cellular proteins
  3. Form pores in cellular membranes
  4. Interfere with nerve transmission
  5. Non-specific activation of T cells
96
Q

Corynebacterium diphtheriae toxin

A

Inhibits protein synthesis

Acts at elongation factor-2

97
Q

S. dysenteriae toxin

A

Shiga toxin
Inhibits protein synthesis
Damage intestinal epithelium and glomerular endothelial cells
Leads to kidney failure

98
Q

V. cholerae toxin

A

Hyperactivation of cellular proteins

99
Q

Staph aures toxin

A

Creates pores causing hemolysis and tissue damage via LOSS OF IONS
Indirect cell lysis

100
Q

C. perfringens toxin

A

Membrane-disrupting toxins with phospholipase C activity
Targets cholesterol
Direct cell lysis

101
Q

Clostridium tetani toxin

A

Interferes with nerve transmission

102
Q

What part of LPS is a toxin?

A

Lipid A: endotoxin that stimulates an inflammatory response

103
Q

Digestive enzymes secreted by bacteria

A 
Hyaluronidase
Collagenase
Lecithinase
Fibrinolysin
Streptolysin O
104
Q

Common illnesses from Listeria monocytogenes

A

Food poisoning
Neonatal sepsis
Meningitis

105
Q

Common diseases from Clostridium perfringens

A 
Food poisoning
Necrotizing enteritis
Cellulitis
GAS GANGRENE
Septicemeia
106
Q

Actinomyces diseases

A

Abscesses above diaphragm

Infections after dental work

107
Q

Proprionibacterium illnesses

A

Acne

108
Q

How is diphtheriae transmitted?

A

Respiratory droplets; person to person

109
Q

Where is Listeria monocytogenes found?

A

Intestinal tract of many animals

110
Q

Where is Actinomyces found?

A

Endogenous oral flora

111
Q

Calling card of diphthereiae

A

Bullneck

Myocarditis

112
Q

Sulfur granules

A

Actinomyces

113
Q

First generation cephalosporins

A

Cefazolin

Cephalexin

114
Q

Second generation cephalosporins

A

Cefuroxime

115
Q

Third generation cephalosporins

A

Ceftriaxone

116
Q

Fourth generation cephalosporin

A

Cefepime

117
Q

Extended spectrum penicillins good for…

A

Pseudomonas

Better able to penetrate gram negative porins than aminopenicillins

118
Q

Beta-lactamse inhibitors are combined with…

A

Aminopenicillins

ESPs

119
Q

Most potent, broad spectrum drugs available

A

ESP + Beta-Lactamase inhibitor

Carbapenems

120
Q

Penicillin toxicities

A

Type I hypersensitivity: rash, anaphylaxis

Type II hypersensitivity: hemolytic anemia

121
Q

First gen cephalo’s used for

A

GAS
Viridans
S. pneumo

122
Q

Treat pseudomonas with

A

ESP + BLI
Fourth generation cephalosporin (cefepime)
Carbapenems

123
Q

Hail Mary drug

A

Imipenem

124
Q

Use Vanco for…

A

MRSA
S. pneumo
Enterococci

125
Q

Vancomycin mechanism

A

Cell wall inhibitor

binds to D-Ala-D-Ala building block of peptigoglycan

126
Q

Patient with history of penicillin allergy should not be given….

A

Cephalosporins

127
Q

Carbapenem toxicity

A

Seizures in patients with CNS disease or renal insufficiency

N/V/D

128
Q

Aminoglycosides

A

Streptomycin
Gentamicin
Amikacin

129
Q

Aminoglycosides toxicity

A

Nephrotoxicity

Ototoxicity

130
Q

Macrolides

A

Erythromycin
Clarithromycin
Azithromycin

131
Q

Ketolides

A

Telithromycin

132
Q

Toxicities of Macrolides and Ketolides

A

N/V/D
Inhibition of cytochrome p-450
Visual disturbances

133
Q

DNA gyrase inhibitors

A

Quinolones

134
Q

RNA polymerase inhibitors

A

Rifamycins

135
Q

Anti-folate drugs

A

TMP/SMX

136
Q

Treat CA-MRSA with

A

TMP/SMX

137
Q

TMP/SMX toxicities

A

Rash

GI

138
Q

Treat C. diff with

A

Metronidazole

139
Q

TB drugs block_____

A

Mycoic acid synthesis

140
Q

Treat TB with

A

Isoniazid + Rifapentine

141
Q

Antibiotics that target protein synthesis

A 
Aminoglycosides
Macrolides
Clindamycin
Tetracyclines
Streptogramins
142
Q

Antimetabolites

A

TMP/SMX

Metronidazole

143
Q

T/F

Ceftaroline is active against MRSA

A

True

144
Q

Active against pseudomonas

A

Cefepime
ESPs
Carbapenems
Aztreonam

145
Q

Useful in empiric treatment of CA-pneumonia

A

Levofloxacin

146
Q

Drug of choice for Legionella, Mycoplasma, and Chlamydia

A

Macrolides

147
Q

Used for anerobic infections; many strains of CA MRSA are susceptible

A

Clindamycin

148
Q

Drug of choice for Neisseria gonorrhoeae

A

Ceftriaxone

149
Q

Used for MRSA, strep pneumo, and serious C. diff

A

Vancomycin

150
Q

Commonly used for UTIs, bacterial diarrhea

A

Cipro

151
Q

Used to treat less serious C. diff

A

Metronidazole

CMBM E2 CB (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions