Lecture 2 Flashcards

1
Q

What is the purpose of a peptidoglycan layer?

A

Provides structural integrity of cell wall

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2
Q

What is the purpose of a transpeptidase enzyme?

A

Found in periplasmic space function to crosslink the peptidoglycan chains

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3
Q

What is the MOA of beta-lactams?

A

Binds to transpeptidase which inhibits peptidoglycan synthesis and causing cell wall to lysis

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4
Q

How do Gram + bacteria build resistance towards the beta-lactams?

A

Reduced binding affinity to penicillin binding proteins
Production of B-lactamases
Overproduction of penicillin binding proteins

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5
Q

How do Gram - bacteria building resistance towards beta-lactams?

A

Loss of outer membrane porins
B-lactamases in periplasmic space
Expression of transmembrane efflux pump

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6
Q

What does B-lactamase do?

A

Breaks the B-lactam ring in penicillin
Converts to penicilloic acid

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7
Q

What is the most common antibiotic prescribed?

A

Azithromycin and amoxicillin

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8
Q

What are the first line treatments for penicillin?

A

Strep throat
Syphillis (treponema pallidum)
Cellulitis
Meningitis

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9
Q

What are the cons of penicillin?

A

Increasing resistance
Useless in presence of b-lactamase

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10
Q

What are the pros of penicillin?

A

Cheap and relatively safe

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11
Q

What are the antistaphlococcal penicillins?

A

Dicloxacillin
Oxacillin
Nafcillin
Methicillin (prototype: not used in treatment)

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12
Q

What are antistaphlococcal PCN not effective against?

A

MRSA infections

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13
Q

What are antistaphlococcal PCN used for?

A

Skin and soft tissue staphylococcal infections
(staph aureus and staph epidermidis)

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14
Q

What is methicillin only used for?

A

To identify microbial resistance

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15
Q

What are the aminopenicllins?

A

Amoxicillin and Ampicillin

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16
Q

What additional coverage does aminopenicillins have over penicillins?

A

Better gram - coverage

17
Q

What are the first-line treatment for aminopenicillins?

A

Ottis media and prophylaxis for endocarditis

18
Q

What bacteria causes otitis media?

A

Haemophilus influenzae
Streptococcus pneumoniae
Moraxella catarrhalis

19
Q

Why would amoxillin be preferred over ampicillin?

A

PO intake has better absorption

20
Q

What are aminopenicillins taken with to fight against b-lactamase?

A

B-lactamase inhibitors

21
Q

What are advantages of aminopenicillins over natural penicillins?

A

Higher oral absorption and longer half life
Better penetration of gram- cell wall porins

22
Q

What are the PCN/B-lactamase inhibitor?

A

Amoxicillin/Clavulanic acid
Ampicillin/Sulbactam

23
Q

What coverage does PCN/B-lactamase inhibitor have?

A

Same as amoxicillin but with better staphylococcus coverage

24
Q

PCN/B-lactamase inhibitor is a first line treatment for what?

A

Sinusitis
Pneumonia/COPD exacerbations

25
Q

What are some considerations for PCN/B-lactamase inhibitor?

A

Increased cost
More GI SE
Usually for severe or refractory infections

26
Q

What is the extended spectrum penicillins?

A

Piperacillin

27
Q

What combination of drugs get good pseudomonas coverage?

A

Piperacillin/tazobactam
(Only available in this form as IV)

28
Q

What is piperacillin similar to?

A

To amino-penicillins with the addition of a urea group

29
Q

What do piperacillins cover?

A

PCN with Gram - and pseudomonas and proteus

30
Q

What are piperacillin indicated for?

A

Severe infections
Genital/urinary tract
Peritonitis/Ruptured viscus
Skin/soft tissue
Lower respiratory tract
Septicemia

31
Q

What are the 1st gen cephalosporins?

A

Cephalexin
Cefazolin
Cefadroxil

32
Q

What are the 2nd gen cephalosporins?

A

Cefuoxime
Cefoxitin
Cefotetan
Cefaclor
Cefprozil

33
Q

What are the 3rd gen cephalosporins?

A

Ceftriaxone
Cefdinir
Cefixime

34
Q

What is the 4th gen cephalosporin?

A

Cefepime

35
Q

What is the 5th gen cephalosporin?

A

Ceftaroline