MRSA, MSSA, VRE, VRSA

Question 1

Basically, ALL Penicillins are….

Answer 1

GM +

BUT Penicillase Resistant Pen’s are MSSA

Question 2

Basically, all Cephalosporins are…

Answer 2

MSSA (& from 2nd gen & up they cover Anaerobes)

Question 3

IV Cephalosporins see a ______ spectrum as we go up

Answer 3

WIDER

(more Gr - & Anaerobes)

Question 4

Which Cephalosporins are Anti-pseudomonals?

Answer 4

3rd Gen Ceftazidime & 4th Gen Cefepime (both IV)

(b/c (+) on X group on left, meaning very EW and hydrophilic)

Question 5

Which Cephalosporin is NOT for MSSA?

Answer 5

3rd Gen Cefixime

Question 6

PO Cephalosporins see a _____ spectrum as we…

Answer 6

SHIFT

away from treating GM +’s & towards greater GM -

Question 7

“5th Gen” Cephalosporins:

Answer 7

Ceftaroline fosamil

Ceftobiprole medocaril

GM+ incl. MRSA, MSSA & VRSA

Question 8

Delafloxacin:

Answer 8

unlike all other Fluoroquinolones, it isn’t a Zwitterion

in acidic conditions, it pen’s into MRSA & MSSA better b/c it’s in its NEUTRAL free acid form

Question 9

Vancomycin & Teicoplanin:

Answer 9

ONLY GM+

MSSA, MRSA

anaerobes

Question 10

Linezolid, Tedizolid, Daptomycin:

Answer 10

ALL GM+

MSSA, MRSA, VRSA, VRE

Question 11

Aminoglycosides:

Answer 11

NO ORAL absorption

often combined with Pen’s b/c of synergistic activity against GM+

~GM+ & ~MSSA

GM-

NO ANAEROBES

Question 12

Macrolides:

Answer 12

~GM+ & penumonias & ~ against MSSA

limited GM- & anaerobes

Question 13

Tetracyclines:

Answer 13

BROAD

many GM+, GM- & anaerobes

Mg chelation is necessary

Question 14

Glycopeptide: Oritavancin

Answer 14

BROADER than ALL Glycopeptides

ONLY Glycopeptide with activity against VRSA & VRE, b/c has multiple mech’s of action:
1. Inserts in membrane like Teicoplanin
2. Binds to Pentaglycine
3. Binds D-Ala-D-Ala
4. Disrupts bacterial membrane

t1/2 = 245 hr (weekly/biweekly)