MMBIO 221 Exam 2 Robison Study
Guide |104 Questions and Answers
Disinfection - -destruction of vegetative pathogens; usually on inanimate
objects.
- Antiseptic - -agent which prevents bact. contamination and growth;
usually on living tissue.
- Which agent doesn't necessarily work better at higher concentrations? - -
Alcohol, 70% (goldie lock zone)(60-80% most effective)
(Ethyl and Isopropyl)
-Alcohol is very effective to resistant to inactivation by organic materials
(halogens are not good at this)
- Name the factors that affect a disinfectant activity. - --Contact Time:
longer, the more effective.
-Temperature: higher, the more effective. (moist heat better)
-pH: depends on chemical; some synergy.
-Bioburden: more microbes = longer time.
-Types of Microbes: mycobacteria & spores are more difficult to kill.
-Extraneous matter: organic matter inhibits many disinfectants.
-Proper Exposure: ensure agent gets in.
-Disinfectant concentration: higher = better - exception with the alcohols.
- 2 types of antimicrobials - -1. Alteration of cell walls
2. Interference with protein and nucleic acid structure
- What 3 organisms are used in the AOAC Use-Dilution test? - --
Staphylococcus aureus
-Pseudomonas aeruginosa
-Salmonella choleraesuis
- How to compute D values (decimal reduction time)- - --Time required to
kill 90% (1 log) at a specific temperature.
,-killed 3 logs in 3 mins = 1 min is the D value
- Ionizing radiation - -High energy
Small wavelength (<1nm)
Electron beams, gamma, xray
-Creating ions
-Disrupt H bonds
-Oxidize dble covalent bonds
-Create Hydroxyl radicals (denature DNA)
-Microbes are much more resistant to ionizing radiation than multicellular
organisms
- Non Ionizing radiation - -Low energy
Large wavelength (>1nm)
UV (for air, clear fluid, surfaces)
-Excite electrons
-New covalent bonds
-Affect 3D struct. of proteins and nucleic acids
-T-T dimers disrupt H bond (in DNA)
-Lesion
- Antimicrobial handwash - -4% chlorhexidine
- What Anderson Samplers are used for? - -Air Sampling device.
Mirrors the human respiratory system.
Tests efficacy of filtration system.
Bacterial Filtration Efficiency Test
-Used to test surgical masks
- Semi-critical instrument disinfection - -Peracetic acid- base products
(Like Steriplex HC)
- Counter top or other small surface disinfection - -70-80% ethanol
- Antimicrobial in mop water for large areas like floors - -Substituted
Phenols
- Sterilization of heat-labile plastics (petri dishes) - -Gamma irradiation
- Chemotherapeutic drug:
, Anti-tuberculosis drug that inhibits cell wall synthesis. - -Isoniazid &
Ethambutol
-disrupt formation of arabinogalactan-mycolic acid in MYCObacterial species
- Chemotherapeutic drug:
Commonly combined with trimethoprim; inhibits dihydrofolate synthesis. - -
Sulfonamides (Sulfa drugs)
-Inhibit PABA to DHF step
- Chemotherapeutic drug:
A beta-lactam antibiotic with 2 sites that can be chemically modified. - -
Cephalosporin
-Beta lactams bind to enzymes that cross link NAM subunits--helps inhibit cell
wall synthesis
- Chemotherapeutic drug:
An aminoglycoside; binds 30S ribosome; must be given by injection. - -
Streptomycin
-30s change shape
- Chemotherapeutic drug:
The first antibiotic used in humans. - -Sulfanilamide or penicillin G
- Chemotherapeutic drug:
A macrolide which binds the 50S ribosomal subunit. - -Erythromycin
- Chemotherapeutic drug:
Disrupt nucleic acid synthesis by inhibiting bacterial DNA gyrase. - -
Quinolone
-acts against prokaryotic DNA gyrase--little effect on eukaryotes or viruses
- Chemotherapeutic drug:
A polypeptide antibiotic found in topical ointments; kills group A strep. - -
Bacitracin (ABC)
Guide |104 Questions and Answers
Disinfection - -destruction of vegetative pathogens; usually on inanimate
objects.
- Antiseptic - -agent which prevents bact. contamination and growth;
usually on living tissue.
- Which agent doesn't necessarily work better at higher concentrations? - -
Alcohol, 70% (goldie lock zone)(60-80% most effective)
(Ethyl and Isopropyl)
-Alcohol is very effective to resistant to inactivation by organic materials
(halogens are not good at this)
- Name the factors that affect a disinfectant activity. - --Contact Time:
longer, the more effective.
-Temperature: higher, the more effective. (moist heat better)
-pH: depends on chemical; some synergy.
-Bioburden: more microbes = longer time.
-Types of Microbes: mycobacteria & spores are more difficult to kill.
-Extraneous matter: organic matter inhibits many disinfectants.
-Proper Exposure: ensure agent gets in.
-Disinfectant concentration: higher = better - exception with the alcohols.
- 2 types of antimicrobials - -1. Alteration of cell walls
2. Interference with protein and nucleic acid structure
- What 3 organisms are used in the AOAC Use-Dilution test? - --
Staphylococcus aureus
-Pseudomonas aeruginosa
-Salmonella choleraesuis
- How to compute D values (decimal reduction time)- - --Time required to
kill 90% (1 log) at a specific temperature.
,-killed 3 logs in 3 mins = 1 min is the D value
- Ionizing radiation - -High energy
Small wavelength (<1nm)
Electron beams, gamma, xray
-Creating ions
-Disrupt H bonds
-Oxidize dble covalent bonds
-Create Hydroxyl radicals (denature DNA)
-Microbes are much more resistant to ionizing radiation than multicellular
organisms
- Non Ionizing radiation - -Low energy
Large wavelength (>1nm)
UV (for air, clear fluid, surfaces)
-Excite electrons
-New covalent bonds
-Affect 3D struct. of proteins and nucleic acids
-T-T dimers disrupt H bond (in DNA)
-Lesion
- Antimicrobial handwash - -4% chlorhexidine
- What Anderson Samplers are used for? - -Air Sampling device.
Mirrors the human respiratory system.
Tests efficacy of filtration system.
Bacterial Filtration Efficiency Test
-Used to test surgical masks
- Semi-critical instrument disinfection - -Peracetic acid- base products
(Like Steriplex HC)
- Counter top or other small surface disinfection - -70-80% ethanol
- Antimicrobial in mop water for large areas like floors - -Substituted
Phenols
- Sterilization of heat-labile plastics (petri dishes) - -Gamma irradiation
- Chemotherapeutic drug:
, Anti-tuberculosis drug that inhibits cell wall synthesis. - -Isoniazid &
Ethambutol
-disrupt formation of arabinogalactan-mycolic acid in MYCObacterial species
- Chemotherapeutic drug:
Commonly combined with trimethoprim; inhibits dihydrofolate synthesis. - -
Sulfonamides (Sulfa drugs)
-Inhibit PABA to DHF step
- Chemotherapeutic drug:
A beta-lactam antibiotic with 2 sites that can be chemically modified. - -
Cephalosporin
-Beta lactams bind to enzymes that cross link NAM subunits--helps inhibit cell
wall synthesis
- Chemotherapeutic drug:
An aminoglycoside; binds 30S ribosome; must be given by injection. - -
Streptomycin
-30s change shape
- Chemotherapeutic drug:
The first antibiotic used in humans. - -Sulfanilamide or penicillin G
- Chemotherapeutic drug:
A macrolide which binds the 50S ribosomal subunit. - -Erythromycin
- Chemotherapeutic drug:
Disrupt nucleic acid synthesis by inhibiting bacterial DNA gyrase. - -
Quinolone
-acts against prokaryotic DNA gyrase--little effect on eukaryotes or viruses
- Chemotherapeutic drug:
A polypeptide antibiotic found in topical ointments; kills group A strep. - -
Bacitracin (ABC)
