Term
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Definition
| Addition of chemical stops growth but they're not dead |
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Term
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Definition
| Not only stops the growth but also kills the cells. |
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Term
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Definition
| cells stop growing and die. Then they break open and lyse. |
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Term
Minimum Inhibitory Concentration
(MIC) |
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Definition
use tubes with differing antimicrobial concentrations to determine the minimun amount of antimicrobial chemical needed to prevent microbial growth. Each tube gets the same amount of innoculum
Increase concentration by
0,1,2,5,10,25,50,100,200 |
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Term
| How do you measure Antimicrobial Activity |
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Definition
Agar diffusion Method:
Innoculate the plate with liquid culture and place disks containing different antimicrobial chemicals on the plate and look for the zone of inhibition |
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Term
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Definition
| Area surrounding a disk coated in antimicrobial chemicals that has killed microbes surrounding the disk. |
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Term
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Definition
Kills all organisms including endospores
chlorine gas, chlorine dioxide |
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Term
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Definition
Kills all microorganisms except endospores
Sodium hypochloride (bleach), chlorine, ozone in drinking water, and alcohols |
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Term
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Definition
Reduce micro organism numbers, relatively non toxic; used in food preperation
sodium hypochloride, and cationic detergents
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Term
Antiseptic / Germicides
Examples |
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Definition
kill or inhibit growth of micro organisms; non toxic to human skin
alcohol, hydrogen peroxide, iodine |
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Term
| Why can bleach be used both as a disinfectant and sanitizer? |
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Definition
| Concentration and exposure time are important for the effects they exhibit |
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Term
What are 5 ways that antibiotics act on micro organsisms to prevent growth?
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Definition
1) Cell Wall synthesis - target and inhibit cell wall peptidoglycan polymerization
2) DNA gyrase - blocks DNA synthesis
3) DNA - directed RNA Polymerase - blocks transcriptional RNA polymerase
4) Protein synthesis - blocks ribosomes and prevents protein production
5) Cytoplasmic stucture - blocks lipid synthesis and blocks membrane formation |
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Term
| Broad Spectrum vs. Narrow Spectrum antibiotics |
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Definition
.Broad Spectrum = inhibits many different species ( i.e. inhibiting gram + and gram - )
.Narrow spectrum = inhbiting just a few species |
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Term
Do pharmaceutical companies want to produce Broad or Narrow spectrum antibiotics and why?
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Definition
| They want to produce Narrow spectrum antibiotics so they only kill the specific bacterium and prevent the death of healthy bacterium. |
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Term
| 3 ways antiviral agents work |
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Definition
1) AZT - reverse transcriptase
2) Protease inhibitors
3) Interferon |
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Term
| 4 Modes of Action of Antifungal Chemotheraputic Agents |
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Definition
1) Cell Membrane ( Ergosterol inhibitors) - not found in humans
2) Cell Wall - inhibit chiiting synthesis
3) Nucleic Acid synthesis - good for topical creams because it penetrates fungal cells but not your cells
4) Microtubule formation - good for topical creams because it penetrates fungal cells but not your cells |
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Term
| Why is it so hard to target fungal cells for antifungal agents? |
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Definition
| Fungi have similiar properties to humans, so if we target fungal cells, we must target something specific to fungi that isn't also found in human cells |
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Term
| What makes a bacterial cell resistant? ( 4 things) |
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Definition
1) Naturally resistant - no target or impermeable / dont have what antibiotic is targeting
2) Chemical alteration of antibiotic
3) Pump antibiotic out of cell - if pump moves antibiotic out of cell faster than it is taken in
4) Modify target of the antibiotic - bacteria changes something about its gene to prevent a specific drug from working |
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Term
What factors allow a cell to change from sensitive to resistant?
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Definition
Resistant genes aquired through:
Resistant plasmids
Transposons ( Jumping genes)
chromosomal mutations
genetic exchange with naturally occuring resistant organsisms in the environment |
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Term
What human practices speed the appeard of resistance?
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Definition
1) Medical misuse of antibiotics
- incomplete course of treatment
- use of antibiotics for non bacterial infections
- use of antibiotics for minor infections
2) Agricultural misuse of antibiotics
- use of antibiotics in healthy animals simply for growth promotion |
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Term
Are Methicillin-Resistant Staphylococcus aureus infections increasing or decreasing?
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Definition
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Term
| Drug -Resistant Streptococcus penumoniae |
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Definition
| DRSP is resistant to at least one drug |
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Term
| Ways to avoid drug resistant bacteria |
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Definition
. wash hands
. don't share antibiotics
. take full course of antibiotics
.don't use IV drugs
. avoid operating room tables
. practice safe sex |
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