Lecture 7 - Antimicrobial drugs and therapy Flashcards
(34 cards)
what is chemotherapy?
A treatment that uses drugs to kill rapidly diving cancer cells and also prevent their growth
Who first made Penicillin and what year?
Alexander flemming in 1920
What are sulphonamides?
A group of medicine used to treat bacterial infections
What are the names of the gram-positive rods and the antibiotics they produce?
- Bacillus subtillis - produces bacitracin
- Paenibacillus polymyxa - produces polymyxin
what are the 2 important actinomycetes and the antibiotics they produce?
- Streptomyces nodosus - Amphotericin B
- Streptomycens venezuelae - Chloramphenicol
What are the fungi and antibiotics they produce?
- Cephalosporium Spp. - produce cephalotin
- Penicillum griseofulvum - griseofulvin
- Penicillum chrysogenum - Penicillin
what are the 3 types of antimicrobial drugs
- natural fermentation
- semi-synthetic
- synthetic
what is the broad spectrum of activity?
A spectrum which affects a larger range of gram pos. and gram neg. bactera
what are the pros and cons of the broad spectrum
pros: useful for treatment of an infection prior to MO identification
cons: bad impact on host flora, and risk of opportunistic infections such as Candida albicans and Trichomonas vaginalis
what is Candida albicans?
a system disorder found in mouth, rectum, vagina, and skin folds.
- Thrush
What is a mode of action?
How an antibiotic affects a particular MO and can be bacteriostatic and bacteriocidal
what does bacteriostatic mean?
To keep bacteria in a stationary phase
what does bacteriocidal mean?
To kill the bacteria
what are the 5 modes of action?
- Inhibition of cell wall synthesis
- Inhibition of protein synthesis
- inhibition of nucleic acids
- injury to plasma membrane
- inhibition of essential metabolite synthesis
explain what inhibition of cell wall does, and the antbiotics that do it
- without cell wall, there is no protection, and osmotic pressure causes lysis
- Penicillin messes with the cross linking of peptidoglycan in the bacterial cell wall, mostly affects gram positive cells/
what does protein synthesis Inhibition do, and what are the antibiotics?
- stop ribosomes from translating mRNA into proteins
- streptomycin, chloramphenicol, tetracycline, and erythromycin
what happens when antibiotics alter the plasma membrane, and what are the antibiotics that do it?
- permeability is altered , and frequently affects fungi
- Amphotericin B and Ketoconazole
what is amphotericin used for?
to treat serious fungal infections
what is ketoconazole used for?
to treat serious skin infections and to prevent them from coming back.
what happens when nucleic acid synthesis is inhibited, and what are the antibiotics that do it.
- Prevent MO reproduction and growth by affecting DNA and proteins for growth
- Quinolones such as ciprofloxacin.
what happens when essential metabolites are inhibited, and what antibiotics do that?
- affect a molecule necessary for cell survival, and prevent synthesis by competing for an enzyme in a metabolic pathway
antibiotic: sulphonamides - Sulfanilamide.
what happens when essential metabolites are inhibited, and what antibiotics do that?
- affect a molecule necessary for cell survival, and prevent synthesis by competing for an enzyme in a metabolic pathway
antibiotic: sulphonamides - Sulfanilamide.
What 2 groups are targeted by antibiotics
MOs and structures
what is the chemical structure of penicillin
Beta-lactam ring
