Antibiotics Flashcards Preview

RUSVM Bacteriology Gram Negatives > Antibiotics > Flashcards

Flashcards in Antibiotics Deck (14):
0

Mainly against active growing gram positives, prevent cross linking of peptidoglycan chains so bad cell wall synthesis

Penicillin & cephalosporins

1

Disrupt cell membranes by binding to membrane phospholipids --> structural disorganization. Maybe nephro/neurotoxic

Polymixin B&E , topical

2

Block 30S ribosomal activity against gram negative bacteria. Nephrotoxic and ototoxic

Aminoglycosides - Streptomycin & Neomycin

3

Block 30S by not blocking tRNA binding

Tetracyclines : macrolides

4

Block 50S ribosomal activity

Chloramphenicol

5

Block 50S; Contraindicated in horses & neonates

Lincosamides

6

Block 50S activity, mainly against gram positives and some mycoplasmal pathogens

Macrolides : erythromycin & tylosin

7

Block DNA directed RNA polymerase, inhibits transcription, antimycobacterial ( use with erythromycin for R. Equi Tx)

Rifampins

8

Block DNA gyrase, no DNA unwinding, no replication. Use for mastitis Tx

Novobiocin

9

Blocks DNA gyrase, Tx of enteric infections and intracellular pathogens

Quinolones (enrofloxacin), nalidixic acid

10

Block pathway of making folic acid

Sulfonamides

11

Combines with enzyme dihydrofolate to block nucleic acid synthesis

Trimethoprim

12

Antibiotic synergism - two pairs

Penicillins & Aminoglycosides (inhibit cell wall synthesis & allow aminoglycosides entry)
- Sulfonamides & Trimethoprim (inhibit frolic acid synthesis, work together)

13

Antibiotic antagonism (one pair)

Penicillin & bacteriostatic antibiotics (penicillin acts in cell walls of growing bacteria, doesn't work if growth stops)