Drugs, Microbes, and the Host Flashcards
chemotherapeutic drug
any chemical that’s used to treat, relief or prophylaxis of a disease
prophylaxis
prevent potential for future infections
antibiotic
drug that kills bacteria
Gerhard Domagk discovered
sulfonamide could work as a antibacterial drug inside the human body accidentally
Alexander Fleming
discovered first natural antibiotic penicillin
Bacteria/Fungi that produce antibiotics
bacillus and streptomyces (1/3 from streptomyces)
What do antibiotics target?
disrupt cell processes or interfere with the formation or structures of the cell
narrow spectrum
a drug that is effective on a small range of microbes
broad spectrum
affects a large number of microbes
Effect of broad spectrum drugs
effect natural resident microflora in your body, more likely to lead to evolution of resistance
folic acid
makes nucleotides and amino acids (humans consume this)
antibiotic or antimicrobial drug groups
280 different types of antibiotics that are grouped into about 24 different families
penicillins (-pyin)
target bacterial cell wall synthesis (beta-lactam); binds to the active site inhibiting the synthesis of peptidoglycan
penicillinase
an enzyme that destroy penicillin in bacteria
Augmentin
combines a penicillin drug with a second chemical that blocks penicillinase for more effective penicillin
cephalosporin
fungus which produces antibiotics (cef, ceph, kef)
cephalosporin advantages
fewer instances of allergies and also less resistance develop
carbapenems
resistant endobacteria
beta-lactam antibiotics
cephalosporin, penicillin, carbapenems
polymyxins
target the cell membrane of bacteria
fluoroquinolones (-floxacin) broadspectrum
bind to topoisomerase; prevents that enzyme from functioning and thereby blocks DNA replication itself keeping the cells from dividing and essentially killing them
Aminoglycosides
interfere with protein synthesis
Tetracyclines
inhibit protein synthesis by binding to the 30s ribosomal subunit to block it
Chloramphenicol
interferes with protein synthesis by binding to the 50S ribosomal subunit
Macrolides
binds to the 50s ribosomal subunit inhibiting translocation
Sulfonamides
inhibits folic acid metabolism
antifungal
polyenes and azoles
fluoroquinolones are
synthetic
most toxic drug to humans
chloramphenicol
Penicillins and cephalosporins
block cross-linking of peptidoglycan.
antimicrobic that does not inhibit cell wall synthesis
gentamicin
Antibiotics that are macrolides
include azithromycin and erythromycin.
Species of Bacillus produce
polymyxins.
one way antihelminthic drugs work against the helminth
They paralyze it
Acyclovir
treat genital herpes.
NOT a mode of action of an antiviral
Bond to ergosterol in the cell membrane
mode of action of antiviral
Block viral assembly, Inhibit DNA synthesis, Block viral entry into a host cell, Block transcription and translation
An antiviral that is a thymine analog would have an antiviral mode of action that
blocks DNA synthesis.
Why has the United States and Europe banned the use of human drugs in animal feeds?
Because it contributes to the growing drug resistance problem.
How long have the genes for antibiotic resistance been around?
For millions to billions of years
The Kirby-Bauer test
agar surface, seeded with the test bacterium, to which small discs containing a specific concentration of several drugs are placed on the surface.
A superinfection results from
decrease in most normal flora with overgrowth of an unaffected species.
antimicrobials is contraindicated for children due to permanent tooth discoloration
tetracycline
Janice has just had hip replacement surgery and her physician has prescribed antibiotics and directed her to take them every time she has a dental appointment. This is an example of antibiotic
Janice has just had hip replacement surgery and her physician has prescribed antibiotics and directed her to take them every time she has a dental appointment. This is an example of antibiotic
