antibiotics

Penicillin

now used to refer to over 50 related antibiotic- affect cell wall synthesis Gram -

Cephalosporins

similar structure to penicillin, resistant to penicillinase, more effective for Gm-, susceptible to other beta-lactamases, mostly injected (some oral), expensive- effect cell wall synthesis

Bacitracin

mainly effective against Gm+, topical use only, stops synthesis of linear strands of peptidoglycan-  effect cell wall synthesis

Vancomycin

Effective against penicillinase producers. Stops synthesis of cell wall. Was the last line of antibiotic defense for treating Staphylococcus aureus strains resistant to other antibiotics (MRSA). Problem- they’ve developed resistance-now a different last line.- effect cell wall synthesis

Aminoglycosides

changes the 30s subunit shape, effective against gram negative bacteria, can cause damage to auditory nerve and kidneys, ex: streptomycin and gentamicin- inhibit protein synthesis 

Tetracyclines

stop tRNA attachment, broad spectrum, long retention in body and penetration, Commonly used in animal feed becoming more of a concern more resistance because of it in the environment, Discolored teeth in children and not given to pregnant women- liver damage-inhibit protein synthesis 

Chloramphenicol

simple structure, Inhibits peptide bond formation, Broad spectrum but toxicity problems, ready diffusion, inexpensive used in low-cost situations, aplastic anemia- individuals stop producing all blood cells-needs bone marrow transplant-inhibit protein synthesis

Macrolides

Stops MRNA through ribosome, gram positive bacteria- not very effective on gram negative, oral antibiotic for children, ex: erythomycin- inhibit protein synthesis Gram +

Polymyxin B

1. Bacterialcidal- But higher toxicity to patient especially kidneys and nervous cells

   1. We have plasma membrane very similar between eukaryote and prokaryote can carry over toxicity

2. gram negative bacteria really affects lipopolysaccharides

3. Often combined with neomycin in tropical ointments- plasma membrane

Rifamycin

Inhibits synthesis of mRNA, we have mRNA but ours is different than the enzymes in the bacteria- the antibiotic gets after different enzymes, penetrates tissues, red urine saliva sweat or tears, ex: rifampin-plasma membrane

Quinolones

Bacteriocidal, inhibits DNA replication, synthetic drug called nalidixic acid, lead to fluoroquinolones being developed- plasma membrane

Sulfonamides

Synthetic antibiotics, inhibit enzyme involved in the production of folic acid, bacteriostatic and broad spectrum, allergic reactions common- inhibitors of metabolic pathways

Isoniazid

Treat TB, has to penetrate human tissue because that’s where bacteria are hiding, affects enzyme for my colic acid synthesis- inhibitors of metabolic pathways