Chapter 12 Antimicrobial drugs and anti fungals

____________ is the use of drigs to treat a disease

chemotherapy

these type of drugs interfere with the growth of microbes within a host

antimicrobial drugs

A good drug has _____ ______.

• it has more effect on the microbial cells/infectious agent than the host cells

selectivity toxicity

more than 50% of currently used antibiotics originated from which species

streptomyces

what are broad spectrum antibiotics

antibiotics which work on a wide range of microbes

This antibiotic inhibits cell wall synthesis

penicillin

which drug is this

• acts by preventing cross-linking of peptidoglycans in cell wall

• inhibits cell wall synthesis

• comes in natural or semi-synthesic

penicillin

what are the two natural penicillins

Penicillin G and V

Penicillin has two natural penicillins (occuring in nature), Penicillin G and Penicillin V.

What is this?

• penicillin _ is injected…and why

Penicillin G is degraded by stomach acids so it is injected

Penicillin has two natural penicillins (occuring in nature), Penicillin G and Penicillin V.

What is this?

• penicillin _ is used orally… and why

Penicillin V is more resistant to stomach acids so it can be used orally

what antibacterial antibiotic is this…

• MORE EFFECTIVE AGAINST MORE GRAM NEGATIVE SPECIES

• resistant to penicillinase

• can cross blood barrier

Cephalosporins

what are the two types of anti-mycobacterial antibiotics

• Isoniazid (INH)

  • Inhibits mycolic acid synthesis

• Ethambutol

  • Inhibits incorporation of mycolic acid

what antibacterial antibiotic is this?

• binds 50s ribosomal subunit and inhibits polypeptide bond formation

• can have effects on bone marrow

chloramphenicol

what antibacterial antibiotic is this

• originates from streptomyces spp.

• interferes with tRNA attachment

tetracyclines

which antibacterial antibiotic is this

• binds to 50s subunit to prevent translocation

• effective against gram positive bacteria

macrolides better known as erythmolysin

Chloramphenicol

binds to 50s portion and inhibits polypeptide formation

tetracycline

interferes with attachment of tRNA to mRNA-ribosome complex

streptomycin

changes shape of 30S portion, causing code on mRNA to be read incorrectly

what are the drugs that inhibit protein synthesis

• macrolides

• tetracyclines

• chloramphenicol

• aminoglycosides(streptomycin, neomycin, gentamicin)

what drugs inhibit cell wall synthesis

• penicillin

• cephalosporins

• polypeptide antibiotics (bacitracin/vancomycin)

• Mycobacterial

what drug is this?

• injury to the plasma membrane

• little selective toxicity

• topical treatments

polymyxin B

what drug is this

• inhibits RNA synthesis

• penetrates tissues including cerebro spinal fluid

• used in treatment for tuberculosis and leprosy

• inhibitor of nucleic acid synthesis

rifamycin

what drug is this

• inhibits DNA gyrase

• treats UTI

• and anthrax

quinolones and fluoroquinolones

list the drugs that inhibit nucleic acid synthesis

• Rifamycin

• Quinolones

• Fluoroquinolones

what is this drug

• inhibits folic acid synthesis due to structural similarity to PABA

sulfonamides (sulfa drugs)

this macrolide is an alternative to penicillin

erythromycin

list the competitive inhibitors

sulfonamides

watch the animation available in wiley plus

betty jetty

There are three main classes of antifungal drugs…

• Polyenes

• Azoles

• Echinocandins

- which one targets membranes

polyenes

There are three main classes of antifungal drugs…

• Polyenes

• Azoles

• Echinocandins

- which one targets ergosterol synthesis

azoles

this drug

• inhibits synthesis of ß-glucans

echinocandins

this drug…

• is a cytosine analog and inteferes with RNA synthesis

flucytocine

this drug

• blocks microtubule assembly and therefore cell division

griseofulvin

this drug…

• is used in the treatment of athelet’s foot

tolnaftate

this drug…

• blocks folic acid synthesis

sulfamethoxazole/trimethoprim