Cell Wall Synthesis Inhibitors

Question 1

Cell wall synthesis inhibitors

Answer 1

Beta-lactam Antibiotics - Penicillin’s, Cephalosporins
Vancomycin

Question 2

Stage 1 of cell wall synthesis, assembly of cell way subunits in the cytosol, is inhibited by ________ and __________

Answer 2

fosfomycin, cycloserine

Question 3

Stage 2 of cell wall synthesis, polymerization of subunits at cell membrane, is inhibited by __________

Answer 3

vancomycin

Question 4

The target of vancomycin is _______

Answer 4

transglycosylase (Stage 2)

Question 5

Stage 3 of cell wall synthesis, cross-linking of peptidoglycan polymers occurring in the cell wall, is inhibited by _________ and ___________

Answer 5

Penicillins and cephalosporins

Question 6

Penicillins and Cephalosporins target __________ and _____________

Answer 6

penicillin binding proteins (PBPs) - transpeptidase and carboxypeptidase

Question 7

Antibiotics that inhibit cell wall synthesis are cidal or static?

Answer 7

cidal

Question 8

The mechanism of action for penicillins is what?

Answer 8

inhibition of reactions involving transpeptidation

Question 9

What is the resistance mechanism to Beta-lactams?

Answer 9

1. beta-lactamase/inactivation
2. Target modification of PBPs
3. Decreased permeability (porins)

Question 10

2 types of B lactamase to know:

Answer 10

Narrow spectrum beta-lactamases (penicillinases)
Extended spectrum beta-lactamases (ESBLs)

Question 11

Which bacteria make penicillinases? (narrow spectrum beta-lactamases)

Answer 11

1. 99% of S. aureus
2. 100% of klebsiella
3. 20-30% of E. coli

Question 12

Which bacteria are known to make cephalosporinases? (Extended spectrum beta-lactamases)

Answer 12

GNRs - E. coli, K. pneumoniae

Question 13

Penicillinases (NSBL) and cephalosporinases (ESBL) can both be inhibited by ____________

Answer 13

beta-lactamase inhibitors

Question 14

Two inhibitors of NSBL and ESBL

Answer 14

Clavulanic acid & Tazobactam
(Augmentin & Zosyn)

Question 15

What degrades penicillins and cephalosporins and is not inhibited by beta-lactamase inhibitors?

Answer 15

AmpC

Question 16

KPC-NDM-1 is found mainly in _______ and _______ (what bacteria)

Answer 16

E. Coli and Klebsiella spp

Question 17

KPC-NDM-1 is inhibited by _______ which is found in ________

Answer 17

avibactam, ceftazidine

Question 18

Two types of altered PBPs that cause beta-lactam resistance are :

Answer 18

1. New PBP - MRSA (mecA)
2. Alter existing PBP - strep. pneumo, N. gonorrhea

Question 19

The _______ gene in _____ alters the number of porin channels decreasing antibiotic susceptibility for hydrophilic antibiotics that need to enter the cell

Answer 19

OprD, Pseudomonas

Question 20

The most common mechanism of resistance to methicillin or dicloxacillin by S. aureus is what?

Answer 20

Acquisition of the novel protein PBP2a

Question 21

MSSA are resistant to all penicillin’s (except dicloxacillin) due to production of ________.

Answer 21

penicillinase (NSBL), dicloxacillin

Question 22

MRSA is resistant to antibiotics that target stage ____ due to PBP2a (new target), but sensitive to drugs like vancomycin that target stage ___

Answer 22

3, 2

Question 23

4 infections caused by Streptococci:
Antibiotics?

Answer 23

1. pharyngitis
2. pneumonia
3. sinusitis
4. otitis media
   (URIs)

Pen V, Amoxicillin +/- clavulanate

Question 24

Staph aureus: type of infection? Antibiotics?

Answer 24

• Localized cutaneous infections
• MSSA = Dicloxacillin (penicillinase-resistant penicillins)
  -MRSA = no penicillins/beta lactams, vanco, cyclines, clindamycin

Question 25

M. Catarrhalis: type of infection?

Answer 25

otitis media, CAP

Question 26

Bacteria Pen G is used for:

Answer 26

Enterococci, neisseria meningititis, bacillus anthracis (anthrax), cornyebacterium diptheria

Question 27

What penicillin is used to treat pseudomonas?

Answer 27

Pip-Tazo

Question 28

Amoxicillin Clavulanate is used to treat what?

Answer 28

M. catarrhalis, streptococci

Question 29

what type of bacteria are E. coli and pseudomonas?

Answer 29

gram negative rods

Question 30

What type of bacteria is neisseria?

Answer 30

gram negative cocci

Question 31

Infections caused by E. coli:

Answer 31

UTIs, diarrhea, hemorrhagic colitis

Question 32

Infections caused by Psuedomonas:

Answer 32

opportunistic infections in any organ or tissue

Question 33

_______ _______ is an anerobic bacteria that causes intraabdominal and brain abcess and is treated with __________

Answer 33

Bacteroides fragilis, Piptazo

Question 34

_______ is an anerobic bacteria that causes gas gangrene, and food poisoning and is treated with _____

Answer 34

Clostridium perfringens, Pen G

Question 35

What is used to treat syphillis? (treponema pallidum)

Answer 35

Pen G

Question 36

What is used to treat lyme disease? (borrelia burgdorferi)

Answer 36

amoxicillin

Question 37

Which penicillins have good oral absorption?

Answer 37

Pen V and amoxicillin

Question 38

Which penicillin is IV only?

Answer 38

Piperacillin, Pen G

Question 39

T/F penicillins are excreted via the kidney and should be renally dosed?

Answer 39

T

Question 40

Pen G or V is more powerful and is used for serious infections?

Answer 40

Pen G, IV only

Question 41

A penicillinase resistant penicillin is ______

Answer 41

dicloxacillin – treats MSSA

Question 42

______ and _______ are extended spectrum penicillins that are given with beta lactam inhibitors and have increased penetration through porins of gram-negative bacteria

Answer 42

Amoxicillin and ampicillins

Question 43

Piperacillin must be given via what route?

Answer 43

parenterally - any route except oral

Question 44

Piperacillin is useful in infections caused by what 3 organisms?

Answer 44

B. fragilis (anerobe)
Pseudomonas
Enterococci