Flashcards in Ch 20 Antimicrobial Drugs Deck (50)
What is an antibiotic?
A substance produced by microbes that inhibits other microbes.
What's the name for synthetic sulfa drugs?
What is antibiotic resistance?
Formerly effective medications have less impact on bacteria
Is it easy to find drugs against prokaryotic cells that don't affect eukaryotes?
Are fungi, protozoan or helminths difficult to treat?
Yes because their cellular structure is alike human cells.
What is a superinfection?
When the pathogen develops resistance to antibiotics.
What are the five major action modes of antibacterial drugs?
Cell wall processes - penicillin
Protein synthesis - tetracycline
Nucleic acid replication - rifampin
Plasma membrane processes - polyxin B
Metabolism - sulfanilamide
How could a magic bullet work?
Not affecting host cells
What is another name for chemotherapy?
Finds and destroys pathogens but not harm the host.
How is the Disk Diffusion Test run?
An agar plate is uniformly inoculated
Chemotherapeutic disks are placed
Zones of inhibitions form
Largest zone, best performing drug
What is the E test?
The minimal inhibitory concentration, MIC, of a drug is found. The epsilometer shows the lowest concentration that blocks bacterial growth.
What is a broth dilution test?
The minimal bactericidal concentration, MBC, of an antimicrobial drug is found.
What are the four mechanisms of microbial resistance to antimicrobial drugs?
Draw Fig. 20.20
Inactivation by enzymes
Alteration of target molecule
Effluent of antibiotic drug
Which are more resistant to antibiotics, Gram negative or Gram positive?
Gram negative are more resistant because of their less permeable cell walls and porins.
What is the therapeutic index?
Measuring risk vs. benefit
What is a bacteriophage?
A virus that attacks bacteria.
What are bacteriocins?
Bacterial toxins produced to inhibit the growth of similar bacteria.
What is a persister cell?
A surviving bacteria that has resistant characteristics.
Who discovered penicillin?
What is the difference between narrow and broad antibiotics?
Broad kill the infection and many other desirable bacteria; narrow only kill the intended target.
What is a beta-lactam ring, what drugs use it, and what does it do?
The β-lactam ring is named because the nitrogen atom is attached to the β-carbon atom relative to the carbonyl. It is the core structure of penicillins. Nearly all of these antibiotics work by inhibiting bacterial cell wall biosynthesis.
What are macrolides?
Erythromycin 50 S
Remember Christmas decoration
What is an abscess and how do they relate to microbiology?
An accumulation of pus.
Bacterial accumulation infection.
S. aureaus and S. pyrogenes
What is meningitis?
Inflammation of the meninges caused by viral or bacterial infection
What are protease inhibitors?
Protesase is an enzyme that breaks down proteins, so the protease inhibitor stops viruses like HIV.
What are integrase inhibitors?
Antiretroviral drug designed to block the action of integrase, a viral enzyme that inserts the viral genome into the DNA of the host cell.
What is a virus?
DNA or RNA in a protein coat. Very small.
What are inferons and name a drug that promotes interferon production?
Used against viruses that inhibits warts.
What type of drug is used to treat malaria and what is a specific example?
Antiprotozoan - mosquitoes
Choloroquine - from tree bark