MCB 3020 Chapter 9- Antimicrobial Chemotherapy

Paul Ehrlich

Used dyes to treat African sleeping sickness

Sahachiro Hata

Used arsenic, or Salversan, to treat syphilis

Domagk and Trefouel

Discovered sulfonamides and sulfa drugs

Florey, Chain, and Heatley

Get the credit for discovering penicillin

True antibiotic

Antibiotics made by a living organism

Synthetic antibiotic

Antibiotics made in a lab

Semisynthetic antibiotic

Antibiotics that use a living organism and modifies it

Streptomyces

Bacteria that looks like a fungus on a Petri dish; produces antibiotics

Selective toxicity

A drug that kills harmful microbes without damaging the host

Narrow antibiotics

Antibiotics that will only kill specific bacteria

Broad antibiotics

Antibiotics that can target a wide range of bacteria

Therapeutic index

The ratio between the toxic and therapeutic concentrations of a drug

Cell wall inhibitors

Most effective antimicrobial; targets peptidoglycan

Metabolic antagonists

Second effective antibmicrobial; identify biochemical pathways that are present in bacteria but not in humans

Protein synthesis inhibitors

Third effective antibiotic; binds to the ribosomal RNA and affects translation but could potentially affect the mitochondria

Nucleic acid synthesis inhibitors

Least effective type of antibiotic; can affect DNA/RNA polymerase

Minimal inhibitory concentration (MIC)

How much of a drug is needed to stop bacteria from replicating; not killing the bacteria

Minimal lethal concentration (MLC)

How much of a drug is needed to kill the bacteria

Penicillins

True antibiotic (fungus) with a β-lactam ring that inhibits transpeptidation of the third amino acid in peptidoglycan

Ampicillin

A type of semisynthetic, broad-spectrum penicillin that fights against Gram-negative bacteria

Penicillin V and G

Types of penicillins that fight against Gram-positive only

Cephalosporins

True antibiotic (fungus) that comes from the fungus Acremonium; used for most patients allergic to penicillin

Zevetra

A semi-synthetic, cephalosporin based drug

Carbapenem

Broad spectrum antibiotic that is a hybrid of penicillin and cephalosporin

Vancomycin

True antibiotic (bacteria) that inhibits transpeptidation of the terminal alanine; previously considered "drug of last resort"

VRE (vancomycin-resistant enterococcus)

Bacteria that have developed resistance to the antibiotic vancomycin

Aminoglycosides

Bactericidal drug that binds to 30S; can be toxic and cause renal damage

Streptomycin, kanamycin, neomycin

Types of aminoglycosides made by bacteria Streptomyces spp.

Gentamicin

Type of aminoglycoside from bacteria Micromonospora purpurea

Tetracyclines

Four-ring structure that binds to 30S; broad spectrum, bacteriostatic; can cause black teeth

Macrolides

12-22 carbon ring that binds to 23S rRNA; used for patients allergic to penicillin

Azithromycin

Type of macrolide that can treat chlamydia

Erthyromycin

Type of macrolide that is broad spectrum and bacteriostatic

Lincosamides

Type of broad spectrum, bacteriostatic antibiotic that binds to 23S rRNA and is used against anaerobic microbes; can support growth of C. difficile

Clindamycin

Type of lincosamide that is used to treat CA-MRSA

Chloramphenicol

First broad-spectrum antibiotic that binds to 23S rRNA that is not allowed in food producing animals

Oxazolidinones

Bacteriostatic, synthetic drugs that bind to 23S rRNA that works against MRSA, VRE, etc.; only used in hospitals

PABA

Needed to make folic acid

Sulfa drugs

Synthetic antibiotics that inhibit the making of folic acid; DO NOT inhibit the making of PABA

Folic acid

Necessary to make methionine and nucleic acids

Trimethoprim

Synthetic antibiotic; combined with sulfa drugs to increase efficacy of treatment (Bactrim)

Synergistic

Working better together

Fluoroquinolones

Synthetic drug that inhibit bacteria DNA-gyrase and topoisomerase IV; broad spectrum, bacteriocidal; prescribed for UTIs

Nalidixic acid

First synthesized quinolone

Norfloxacin

First quinolone approveed for human use

Rifamycins

Blocks transcription by binding to RNA-polymerase (β-subunit); may cause red sweat and urine

Rifampin

Most used type of rifamycin

Prophylaxis

Prevention of disease; before coming in contact

Amantadine

Type of antiviral drug that is used to prevent influenza infections; blocks penetration and uncoating of influenza virus

Tamiflu

Type of antiviral drug that is a neuraminidase inhibitor; not a cure for influenza

Acyclovir

Type of antiviral drug for herpesvirus; inhibits viral DNA polymerase

Adenine arabinoside

Type of antiviral drug for herpesvirus; inhibits DNA and RNA synthesis and function

HAART

A drug "cocktail" used to fight HIV

Ergosterol

Cell membrane of fungi

Amphotericin B

Type of antifungal drug that binds ergosterol in membranes

5-flucytosine

Type of antifungal drug that disrupts DNA and RNA function

Fluconazole

Type of antifungal drug that has low side effects, used prophylactically; made for HIV and immunocompromised patients

Bacteriostatic

Inhibits bacterial growth/replication without killing the bacteria

Bactericidal

Capable of killing bacteria

Immunocompromised

Having an impaired immune system, should be given bacteriocidal antibiotics