Brainscape's Knowledge GenomeTM

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


See full index

Host and Defense > Week 4 > Flashcards

Week 4 Flashcards

1
Q

Name the major types of antimicrobials that affect cell wall synthesis

A

Beta lactams

other antimicrobials such as Vancomycin and bacitracin and daptomycin

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

What are the 6 classes of B-lactam antibiotics?

A

Natural Penicillins

Amino penicillins

Penicillinase-resistant penicillins

Anti-pseudonomal penicillins

Cephalosporins

Carapenems

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

Name 11 penicillins

A 
Amoxicillin 
Ampicillin 
Dicloxacillin
Indanyl carbenicillin 
Nafcillin
Methicillin
Ticarcillin
Oxacillin
Piperacillin
Penicillin G
Penicillin v-K
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How many generations exist for cephalosporins?

A

5

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

Name two antimicrobials in the first cephalosporin generation

A

Cefazolin

Cephalexin

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

Name three cephalosporins in the second generation

A

Cefaclor
Cefuroxime
Cefoxitin

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

Name four cephalosporins in the third generation

A

Cefdinir
Cefotaxmine
Ceftazidime
Ceftriaxone

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

Name one antimicrobial of the fourth cephalosporin generation

A

Cefepime

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

Name one antimicrobial of the fifth cephalosporin generation

A

Ceftavoline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Name three antimicrobials of the carbapenems

A

Ertapenem
Imipenem
Meropenem

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

Name one monobactam antimibrobial

A

Aztreonam

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Name three B-lactam inhibitors

A

Clavulanic acid
Sulbactam
Tazobactam

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe how B-lactam drugs work

A

They target the transpeptidase enzyme* (penicillin-binding protein) which is located on the bacteria’s cytoplasmic membrane

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

What does transpeptidase PBP enzyme do in bacteria?

A

This enzyme carries out the last step of peptidoglycan wall synthesis by creating transpeptide links in between the peptidoglycan chains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Are B-lactam antimicrobials bacteriocidal or bacteriostatic? Why?

A

They are bacterocidal because it will cause the peptiglycan walls to fail, causing the bacteria to lyse due to osmotic forces

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

Are b-lactam drugs more effective against actively proliferating microbes or slowly proliferating microbes? Why?

A

Actively proliferating, because they inhibits cell wall SYNTHESIS

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

Why are B-lactams ineffective against mycoplasms?

A

These bacteria have no cell wall

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

How should you prescribe doses for B-lactams?

A

Since they are type 2 (time dependent), you want o keep their serum concentrations above MIC at least 50% of the time

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

True or false.. natural penicillins are highly susceptible to bacterial b-lactamases

A

True

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

Name two natural penicillins

A 
Penicillin G
Penicillin V (VK)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Natural penicillins have the highest activity against gram ___ organisms

A

Positive

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

Another name for aminopenicillins is ____

A

Extended spectrum penicillin

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

Name two aminopenicillins

A

Ampicillin

Amoxicillin

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

True or false… aminopenicillins re resistant to B-lactamases

A

False. However, they are less susceptible than natural penicillins

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

Another name for penicillinase-resistant penicillins is ____

A

Anti-staphylococcus penicillin

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

Name four penicllinase-resistant penicillins

A

NAFCILLIN*
Methicillin
Oxacillin
Dicloxacicillin

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

True or false.. penicillinase-resistant penicillins are relatively resistant to B-lactamases

A

True

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

Penicillinase-resistant penicillins have lower activity against gram ____ organism and inactivity against gram ___ organisms. However, they are active against ____

A

Positive

Negative

Staphylococcus aureus

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

____ is used to treat staphylococcal infections (but not MRSA). ____ is used as a first-line treatment of choice against staphylococcal endocarditis

A

Nafcillin

Nafcillin

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

Of all the anti-pseudomonal penicillins, which two antimicrobials have the broadest spectrums of activity?

A

Ticarcillin

Piperacillin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Monobactams are a type of ____. They have strong activity against susceptible gram ___ organisms

A

Anti-pseudonomal penicillin

Negative

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

Ureidopenicllins, such as ____, are a subclass of anti-pseudonomal penicillins. They are active against ____

A

Piperacillin

Pseudomonas and gram - rods

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

Cephalosporins are ____ so long as T>MIC is maintained properly

A

Bactericidal

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

What class of antimicrobial has the broadest antibacterial effect?

A

Carbapenems (specifically imipenem)

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

What is the only true naturally occurring penicillin?

A

Penicillin G

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

Penicillin G is _____ hydrolyzed by penicillinase enzymes (B-lactamase)

A

Rapidly

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

How is penicillin G usually administered?

A

IM or IV

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

True or false… penicillin G is good at penetrating the CNS and has a long half life

A

Both statements are false

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

What is the difference between penicillin G and penicillin V?

A

Penicillin V is acid stable, meaning that you can take it orally instead of IM/IV

It has the same Gram + activity but less gram - than G

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is the advantage that aminopenicillins have over natural penicillins?

A

They are extended spectrum penicillins, meaning that they have better gram - coverage

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

Aminopenicillins are the drugs of choice for what three things?

A

Prophylaxis of infective endocarditis*

Listeria monocytogenes

Treatment of UTIs causes by susceptible enterococci

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

Aminopenicillins are usually administered with ___ such as ___, ___, or ____.

A

B-lactamase inhibitors

Clavulunate acid

Salbactam

Tazobactam

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

What is augmentin? What is unasyn?

A

Augmentin - amoxicillin + clavulanate

Unasyn - ampicillin + sublactam

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

Amoxicillin has a ___ oral absorption, ____ Cpmax, ___half life, and ___ likely to cause adverse GI effects than ampicillin

A

Higher

Higher

Longer

Less

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

A drawback to amoxicillin is that it can inhibit renal excretion of ___

A

Methotrexate

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

The drug of choice for prophylactic prevention of endocarditis is ___. If the patient is allergic to this drug, they may take ___ instead. If that still doesn’t work, then you could prescribe ___, ___, or ____.

A

Amoxicillin

Cephalexin

Clindamycin
Azithromycin
Clarithromycin

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

Which is better absorbed orally, ampicillin or amoxicillin?

A

Amoxicillin

It is also not affected by the presence of food when ingesting.

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

What is an adverse effect of ampicillin?

A

Could lead to a superinfection of C. Dificile. —pseudomembranous colitis

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

____ can inactivate ampicillin if mixed

A

Hydrocortisone

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

True or false… ampicillins dampen the effect of oral contraceptives

A

True

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

Parents often give their sick children ampicillin because why?

A

It is in the form of a liquid (the pink bubble gum medicine), so young children can take it

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

Which penicillinase-resistant penicillin is discontinued in the U.S because it made the glomerulus in the kidney ineffective?

A

Methicillin

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

True or false.. penicillinase-resistant penicillins are more potent than penicillin G

A

False, it is less potent

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

True or false… nafcillin can be used to treat MRSA

A

False.. although it is excellent at treating staphylococcal infections, it cannot treat MRSA

Naf for staph!

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

What do probenecids do? How do they do it?

A

The slow renal excretion to retain serum levels of penicillins, cephalosporins, monobactams, and imipenems. Also used to treat gout

They do this by inhibiting organic ion transporters (OATs) in the kidney

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

Why is it that probenecid does not affect the concentrations of nafcillin, oxacillin, and dicloxacillin?

A

These drugs are lipophilic and undergo biliary excretion (through gall bladder, not kidney)

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

Anti-pseudonomal penicillins are used for ….

A

Treating serious bacteremia and UTIs due to bacteria resistant to Pen G and ampicillin

Administer IM or IV, NOT PO

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

Carboxypenicillins are subclass of ____. Two carboxypenicillins are ___ and ____

A

Anti-pseudomonas penicillins

Indanyl carbenicillin

Ticarcillin

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

Indanyl carbenicillin is ___ active and used clinically for management of organisms resistant to ___

A

Orally

Ampicillin

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

Ticarcillin is ___ active than indanyl carbenicillin. It is used for targeting gram ___ bacteria, particularly ____

A

More

Negative

P. Aeruginosa

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

What antibiotic would most likely be given to a patient with an infection of a urinary catheter?

A

Ticarcillin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

____ is the broadest spectrum of the antipseudonomal penicillins

A

Piperacillin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Aztreonam is great for patients with ___ mediated penicillin allergy

A

IgE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

True or false… if you are allergic to penicillin, you are most likely allergic to all other B-lactams

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

Large doses of pen G can produce what symptoms?

A

Lethargy, confusion, twitching, seizures, kidney failure, coma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

Broad spectrum drugs are more likely to result in a super infection. Pseudomembranous colitis can result to taking what 4 drugs?

A

Piperacillin
Cephalosporins
Aztreonam
Aminopenicillins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

How are cephalosporins excreted from the body?

A

Renally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

Depending on the generation, cephalosporins are moderate to broad spectrum. Are they all bacterocidal or bacterostatic?

A

Bacterocidal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

As you increase in cephalosporin generation, it is more targeted towards gram ____, and its B-lactam resistance ____

A

Negative

Increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

Which generation of cephalosporin is active against MRSA?

A

5th

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

True or false.. the first generation cephalosporin penetrates the CNS. It is the first drug of choice when treating any active infection

A

Both statements are false

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

_____ is used for prophylaxis prior to surgery

A

Cefazolin (first generation cephalosporin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

Cefaclor (a second generation cephalosporin) is used to treat ___

A

Sinusitis and otitis due to H. Influenzae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

Cefuroxime is unique in that it can…

A

Cross the blood brain barrier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

Name some features of third generation cephalosporins

A

Very effective against gram - rods

Most can cross blood brain barrier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

Which third generation cephalosporin is active against pseudomonas aeruginosa?

A

Ceftazidime

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

true or false.. cefepime is active in treating MRSA

A

False.. that is a fourth generation cephalosporin

Ceftaroline (5th generation) is active against MRSA

78
Q

What drug has the broadest spectrum coverage available to man?

A

Imipenem , a carbapenem

79
Q

True or false… carbapenems are very stabl in the presence of B-lactamases

A

True

80
Q

Name 2 non-B-lactam antibacterials that affect cell wall synthesis

A

Bacitracin (topical)
-against + and -

Vancomycin
-used to treat endocarditis in penicillin-allergic patients

81
Q

True or false vancomycin active against gram + and groom - bacteira

A

False… just gram +

82
Q

What makes vancomycin unique?

A

It inhibits cell wall synthesis at an earlier point than B-lactams

Poorly absorbed orally

Can cause red man syndrome - rapid infusion induced non-immunological release of histamine

83
Q

Name 2 non-b-lactam antibacterials that affect the cell MEMBRANE

A

Polymyxins - detergent that disrupts membranes. Effective against gram -

Daptomycin - effective against gram + . Alters cell membranes electrical charge

84
Q

How does daptomycin work?

A

Throws off K gradient by inserting a K pore.

Daptomycin is inserted with calcium dependence.

85
Q

Rhabdyomyolosis is an adverse effect of daptomycin. What is it?

A

Muscle pain

86
Q

Describe the progression of symptoms of anaphylaxis

A

Skin
Eyes/nose/gi
Respiratory
Cardiovascular

87
Q

What are the three types of allergic reactions to penicillins/B-lactams?

A

Immediat/acute onset - reactions within 30 minutes, life threatening

Accelerated onset - arise within 30min to 48 hrs after administration. Non life threatening

Delayed onset - longer than two days after administration. Most adverse reactions to penicillin are of this type (mild rashes)

88
Q

Bacteria that are able to take up DNA are said to be ____

A

Competent

89
Q

True or false… most competent bacteria only take up linear DNA through transformation, not plasmids or viral DNA

A

True

90
Q

What is the difference between generalized and specialized transduction?

A

Generalized - if the virus inserts its DNA randomly into the bacterial DNA

Specialized - if the virus enters into the bacterial DNA in a specific site

91
Q

What does the F plasmid code for?

A

A type four sex pilus

These plasmids contain TRA genes, which allow the plasmid to transfer.

92
Q

What are col plasmids?

A

Contain genes that code for bacteriocins (proteins that can kill other bacteria). Some are also toxic to host cells (genotoxins)

93
Q

What are virulence plasmids?

A

Encode virulence factors. These can make a harmless bacterium into a pathogen

94
Q

What are R plasmids?

A

Resistance plasmids. These contain genes that provide resistance against antibiotics or poisons

95
Q

Some plasmids can only be transferred during conjugation if they tag along with other plasmids that contain ___

A

Tra genes

96
Q

True or false… R plasmids typically code for one resistance gene

A

False. They can cary many

97
Q

What is the difference between direct transposition and replicative transposition?

A

Direct transpotion is like cut and paste of a transposable element

Replicative transposition is like copy and paste of a transposable element

98
Q

What are pathogenicity islands?

A

These are condensed segments in the bacterial DNA that house many of the virulence genes

This means that horizontal gene transfer can result in almost immediate virulent strains

99
Q

Commensal E. Coli, if given virulent genes via horizontal gene transfer can become pathogenic. One pathogenic strain is called ___ which causes URIs.

A

Uropathogenic E.coli

100
Q

Does the number of bacteria and diversity of bacteria increase or decrease as you descend the GI tract?

A

Increase

101
Q

What are some good things that our gut microbiota does for us?

A

Helps us extract energy from food

Required for proper immune system development

Affects metabolism of drugs

Protects against pathogens

102
Q

Clostridium difficile is gram ___ and found in low abundance in the GI tract of 5% of humans. It only causes pathogenesis following antibiotic treatment, if so, it may cause ____, which is …

A

Positive

Pseudomembranous colitis - sever ulceration of the colon

103
Q

Clostridium difficile causes what three symptoms? Why is it that C. Difficile can survive antibiotics? (3 things)

A

Diarrhea
Abdominal pain
Fever

Resistance genes and mutations
Biofilm formation
Spore formation*

104
Q

Why is it significant that clostridium can produce spores?

A

The infective spores persist in harsh environments and are hard to kill. They can remain dormant for long periods of time

105
Q

What stimulates the formation of spores by clostridium difficile?

A

Spores form when there is shortage of nutrients

Antibiotics can stimulate spore formation

Any other harsh environment in which the bacteria thinks it will die in

106
Q

Spores have multi-layered protective coats consisting of what five things?

A 
Cell membrane
Thick peptidoglycan mesh
Another cell membrane
Wall of keratin-like protein
Outer layer (exosporium)
107
Q

True or false… most antibiotics and hand sanitizers can kill spores

A

False

108
Q

What two genera produce spores?

A

Clostridium (anaerobic G+)

Bacillus (aerobic G+)

109
Q

What is a nosocomial infection?

A

Hospitally acquired

110
Q

What bacteria spores are likely to be found in the hospital, environment, gas gangrene, and food?

A

Hospital - C. Difficile
Environment - c. Tetani, B. Anthracis
Gas gangrene - C. Perfringens
Food - C. Botulinum, C. Perfringens, B. Cereus

111
Q

Once a bacterial cell is phagocytosed, the phagosome will fuse with a lysosome to form a ___

A

Phagolysosome

112
Q

What are three methods bacteria use to evade host defenses?

A

Some avoid uptake by phagocytes

Some primarily reside within host cells

Some alter their virulence factors and can live in or out of cells (facultative intracellular bacteria)

113
Q

What are survival strategies that bacteira use in the extracellular environment?

A

Production of capsules

Varying of surface exposed antigens (antigenic variation, phase shifting)

Secretion molecules that interfere with host defenses (toxins that modify host cells, enzymes that destroy defenses)

114
Q

What are some things bacteria do to survive within host cells?

A

Developed resistance to reactive oxygen species (by possessing superoxide dismutase) and NO (by suppression of host NO synthase expression)

Neutralize phagolysosome contents

Prevention of phagolysosome fusion

Escape from phagosome

115
Q

What bacterial genera prevent phagolysosome fusion?

A

Mycobacterium

Legionella

116
Q

What bacterial genera escape from the phagosome?

A

Listeria, francisella, rickettsia

117
Q

Listeria monocytogenes is a gram ___, ____ ____. Causes listeriosis (foodborne pathogen). It is a master escape artist because it is able to use its internalins ___ and ___ to engage ___ and trigger actin reorganization of the host cell. This will allow internalization of the bacteira by the host cell

A

Positive, facultative anaerobe

InlA and InlB

Surface receptors

118
Q

How does listeria monocytogenes move around within host cells?

A

Actin-based intracellular bacterial mobility (“actin rockets”)

This will also allow them to spread laterally from cell to cell within tissue

119
Q

True or false… in order to be considered toxins, they must be secreted from bacteria

A

False

120
Q

Name some things that virulence factors can do

A

Cause aberrant activation of host inflammatory response (lipid A*)

Bind and act at host cell surface (super antigen)

Act on host cell membranes (forming pores)

A-B type toxins, includes single chain and multisubunit toxins

121
Q

What are some things that the bordetella tracheal cytotoxin does?

A

Stimulates Nod1. Arrests ciliary movement, causes extrusion of ciliated cells

Coughing
Secondary infections

122
Q

Describe mycobacterium ulcer as polypeptide-derived mycolactone

A

Causes apoptosis/necrosis of host tissue without pain

Buruli ulcers

123
Q

What do exotoxins like superantigens do?

A

Forces APC and T cell together by binding to MHC2. This will cause lots of cytokines to be released and a hyperinflammatory response. This also exhausts and kills T cells

124
Q

What are some things that staphylococcus aureus causes?

A

Food poisoning
Bacteremia
Toxic shock syndrome
Abscesses and cellulitis

125
Q

Many of the virulence factors encoded by S. Aureus are regulated by ___

A

Quorum sensing

126
Q

Prokaryotic ribosomes are made up of ___ and ___ subunits to total ____ whereas eukaryotic ribosomes are made up of ___ and ___ subunits to total ____

A

30s + 50s = 70s

40s + 60s = 80s

127
Q

What are the three big targets of the drugs that disrupt protein synthesis?

A

50s subunit

30s subunit

TRNA synthetase

128
Q

What are the three ribosomal binding sites and what are their functions?

A

A site = holds amino acids to be added

P site = holds growing polypeptide chain

E site = exit site for tRNA

129
Q

True or false… human mitochondrial ribosomes highly resemble bacterial ribosomes. How is this important with dosing?

A

True

At high doses, selectivity is reduced and toxicity increases

130
Q

What are the main differences between prokaryotic mRNA and eukaryotic mRNA?

A

Prokaryotic mRNA is polycistronic and its life span is short because it is unstable

Eukaryotic mRNA is monocistronic and its lifespan is long because it is quite stable

131
Q

What does chloramphenicol do?

A

Binds to 50s subunits and inhibits the formation of the peptide bond

132
Q

What does streptomycin (aminoglycoside) do?

A

Changes shape of 30s subunit, causes code on mRNA to be read incorrectly

133
Q

What does erythromycin (macrolide) do?

A

Binds to 50s subunit and prevents translocation - movement of ribosome along mRNA

134
Q

What do tetracyclines do?

A

Interfere with attachment of tRNA to mRNA-ribosome complex

135
Q

Name 5 aminoglycosides

A 
Gentamycin
Neomycin 
Amikacin
Tobramycin
Streptomycin
136
Q

Aminoglycosides bind to the ___ subunit, changing its ____. What are three consequences of this?

A

30s
Shape

Blocked initiation
Premature termination
Misreading of mRNA

137
Q

Which aminoglycoside is the oldest of the family and has the highest level of bacterial resistance? How is it administered?

A

Streptomycin (IM, IV)

138
Q

What aminoglycoside is the most commonly prescribed aminoglycoside and is often used in combination with penicillins? How is this drug administered?

A

Gentamycin (IV)

139
Q

Which aminoglycoside drug has the broadest spectrum of all aminoglycosides? How is it administered? This is often used for fighting nosocomial infections

A

Amikacin (IM IV)

140
Q

Which aminoglycoside drug has excellent activity against pseudomonas aeruginosa? How is it administered?

A

Tobramycin (IM, IV)

141
Q

Which aminoglycoside drug is used topically only?

A

Neomycin

142
Q

What is a neomycin enema?

A

This is used to flush and detoxify the colon and lower bowel before bowel surgery. Note that this drug is flushed out before it is absorbed

143
Q

Aminoglycosides are primarily used to treat infections caused by ___, gram ___ bacteria

A

Aerobic

Negative

144
Q

Are aminoglycosides bactericidal or bacterostatic? How often should these drugs be taken?

A

Bacterocidal

These are concentration-dependent killing (type 1) but also have some mild post administration effects.

They should be taken daily. They should be taken every 8 hours if you are pregnant, its a neonatal infection, or if it is bacterial endocarditis

145
Q

True or false… aminoglycosides may be taken orally

A

False

146
Q

Why must neomycin be used topically only?

A

It has high nephrotoxicity

147
Q

In anuric patients, half life can ___ by 20x-40x. Why is this significant?

A

Increase

This is significant because aminoglycosides are excreted renally. If they have impaired renal activity, caution should be taken because these drugs’ toxicity is concentration dependent

148
Q

Aminoglycosides have a syngestic relationship with ___ or ___

A

B-lactams

Vancomycin

These drugs break down the cell wall so that the aminoglycosides can get into the bacteria to mess up their protein production

149
Q

What are four adverse effects of aminoglycosides? Describe them

A

Ototoxicity - inner ear damage. Toxicity correlates with the number of destroyed hairs

Nephrotoxicity - kidney damage. Thus, frequent plasma concentration monitoring is essential

Neuromuscular paralysis - decrease ACH postsynaptic sensitivity. Patients with myasthenia gravis at greatest risk. Accumulation in fetal and plasma (teratogenic-so avoid in pregnancy)

Contact dermatitis - common reaction to topical neomycin

150
Q

What four groups are at the most risk for aminoglycoside adverse effects?

A

Elderly (reduced kidney function and reduced ear hair cells)
Impaired renal function patients
Septic patients
Patients with previous exposure to aminoglycisides - can result in functional accumulation (post antibiotic effect)

151
Q

Name four tetracyclines

A

Tetracycline
Doxycycline
Minocycline
Tigecycline

152
Q

Are tetracyclines typically broad spectrum or narrow spectrum?

A

Broad spectrum. Active against gram + and - and atypical intracellular organisms

153
Q

Tetracyclines bind ____ to the ____ ribosomal subunit which will…

A

Reversibly
30s

Prevents attachment of the aminoacyl tRNA

154
Q

Are tetracyclines bacterocidal or bacterostatic?

A

Bacterostatic

155
Q

What class of drugs are often used to treat acne vulgaris?

A

Tetracycline

156
Q

True or false… if bacteria are resistant to one tetracycline, they are resistant to ALL tetracyclines

A

False. Although they are resistant to most, tigecycline is usually still effective

157
Q

True or false… tetracyclines should be taken orally with food

A

False. Although they can be taken orally, oral absorption is altered by diary, iron supplements, or antacids

158
Q

Tetracycline concentrates where?

A

In calcium-hydroxyapatite teeth/bones, or in tumors with high calcium content

159
Q

Name 10 non-oral adverse effects to tetracyclines

A

***Disulfiram-like effect (hangover) (avoid alcohol)

GI upset, hepatotoxicity, headache, metallic taste, PHOTOTOXICITY, vestibular problems, benign intracranial hypertension, itching in anal and genital areas, super Infections of candida and **clostridium difficile (pseudomembranous colitis)

160
Q

True or false… tetracyclines are safe to give to pregnant patients?

A

False!!!

161
Q

Name two oral adverse effects of tetracycline

A

Hairy tongue - due to defective desquamation of the filiform papillae

Deposition in bone and primary dentition - causes discoloration and hypoplasia of developing teeth.
Contraindicated in pregnant patients, breast feeding patients, and in children younger than 8 years, and in patients with liver and renal disease

162
Q

Tigecycline has the same spectrum as other tetracyclines, plus it has activity against….

A

MRSA

Multi-drug resistant S.pneumoniae

Vancomycin resistant enterococci

Some anaerobes

163
Q

What is the clinical use of tigecycline?

A

This drug was developed to overcome tetracycline resistance in complicated skin, soft tissue, and intra-abdominal infections

164
Q

How is tigecycline administered? How is is excreted? It works rapidly in ____ but not effective during ____

A

IV
Bile/fecal

Tissues

Bacteremia

165
Q

What drugs are considered the safest antimicrobials?

A

Macrolides (ketolides)

166
Q

Name three macrolides

A

Erythromycin

Clarithromycin

Azithromycin

167
Q

Macrolides bind _____ to ____ subunits to inhibit the _____ step of protein synthesis

A

Irreversibly

50s

Translocation

168
Q

Are macrolides bacteriostatic or bacteriocidal? Are they broad spectrum or narrow spectrum?

A

Bacteriostatic

Broad spectrum

169
Q

True or false… macrolides can be used to treat MRSA

A

False

170
Q

What are some clinical uses for macrolides?

A

2nd line agents for skin and soft tissue infections (not MRSA), frequently used for upper respiratory infections, and community acquired pneumonia

171
Q

Which macrolides has the longest half-life and volume of distribution?

A

Azithromycin

172
Q

Azithromycin is preferred therapy for urethritis caused by _____

A

Chlamydia

173
Q

What is the difference between endotoxins and exotoxins?

A

Endotoxins are toxic pathogen components (like LPS)

Exotoxins are toxins secreted by pathogens

174
Q

What are four challenges that pathogens present to the immune system?

A

Form diversity

Life cycle diversity

Diverse routes of infection

Rapid, target response over a broad domain

175
Q

True or false… pathogens often infect multiple body compartments

A

True

176
Q

True or false… pathogen physiology changes with life cycle

A

True

177
Q

True or false… single immune response types may clear up a pathogen

A

False

178
Q

What are primary lymphoid organs?

A

Where immune cells originate and develop

Bone marrow
Thymus

179
Q

What are secondary lymphoid organs?

A

Where adaptive immune responses are intiatied and where naive and mature B and T cells reside

Lymph nodes
Spleen
Lymphatic system
Organ-specific lymph-node-like tissues (payers patches, tonsils, etc.)

180
Q

The common lymphoid precursor will give rise to…

A

B cells
T cells
NK cells

181
Q

Common myeloid precursors will give rise to…

A

Monocytes (that give rise to macrophages and dendritic cells)
Granulocytes (which include neutrophils, eosinophils, basophils)
Mast cells

RBCs
Megakaryocytes (give rise to plasmids)

182
Q

True or false.. lymph flow is bidirectional

A

False, it is unidirectional. It involves valves, smooth muscle, pressure gradient, and drains into the venous system

183
Q

What are the three stages to a generalized response to an infection?

A

Immediate innate

Induced innate

Adaptive immune response

184
Q

What three components are part of the immediate innate system?

A

Barriers

Antimicrobial peptides

Complement

185
Q

What are the components of the induced innate immune response?

A

Inflammatory cells (neutrophils, monocytes (macrophages and dendritic cells), natural killer cells

Tissue resident cells (that require activation) - basophils, eosinophils, mast cells

186
Q

What are the three primary antigen presenting cells?

A

Dendritic cells

Macrophages

B lymphocytes

187
Q

Naive lymphocytes are activated in the ___

A

Lymph nodes

If activated, the naive lymphocytes will undergo expansion

Activated lymphocytes travel from the lymph to the infection site

188
Q

What are CD8 and CD4 T cells? What receptor do each of them bind to?

A

CD8 = cytotoxic T cells. These target cells specifically and kills them (CD8 binds to MHC 1)

CD4 = T helper cells. Activate macrophages and B cells (binds to MHC 2)

189
Q

An activated B cell forms numerous ____

A

Plasma cells

190
Q

True or false… antibodies may target more than one antigen

A

False

191
Q

What is the difference between A subunits and B subunits of toxins?

A

A subunit - responsible for enzymatic activity of the toxin

B subunit - mediates binding to a specific receptor and transfer of the A subunit across the membrane

Host and Defense (17 decks)

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