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13 Cards in this Set
- Front
- Back
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Chemotherapy
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the use of drugs to treat a disease
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Antimicrobial drugs
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interfere with the growth of microbes within a host
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Anitbiotic
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A substance produced by a microbe that, in small amounts, inhibits another microbe.
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Selective toxicity
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A good drug has this; this means that it has more effect on the microbial cells that the host cells.
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Antibiotics
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1. more than 50% of currently used antibiotics originated from streptomyces species
2. some from fungi/moulds 3. a few from other bacterial species |
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Spectrum
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the range of microbes that an antibiotic affects
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superinfection
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overuse of broad spectrum antibiotics can lead to this by the pathogenic microbe (normal host microbiota suppressed)
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bactericidal
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anitbiotics which kill bacterial cells are termed this
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bacteriostatic
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antibiotics which suppress the growth of bacteria without killing them are termed this
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The action of Antimicrobial drugs
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1. inhibition of cell wall synthesis
2. inhibition of protein synthesis 3. inhibition of nucleic acid replication and transcription 4. injury to plasma membrane 5. inhibition of essential metabolite synthesis |
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Penicillin G~ Natural
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degraded by stomach acids ( therefore injected)
Disadvantage: Narrow spectrum |
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Penicillin V~ Natural
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more resistant to acids ( so can be used orally)
Disadvantage: Susceptible to penicillinases |
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Semi-synthetic Penicillins
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1. Part natural, part artificially added
2. Overcome disadvantages of natural penicillin's Oxacillin: Narrow spectrum, only gram-positives, but resistant to penicillinase Ampicillin: Extended spectrum, many gram-negatives |
