Sterilization Flashcards
What is the purpose of:
- Laminar flow
- HEPA filter
- UV light
Laminar flow: air circulating
HEPA filter: ensures clean air
UV light: kills microbes
What are safety measures of BSL-3?
- Unidirectional air flow
- Filter in ceiling
- Negative pressure
- Trained personnel
What are the 3 BSL-3 organisms?
- Mycobacterium tuberculosis
- Yersinia pestis (plague)
- Bacillus anthracis
Why did bronchoscopes cause infections even when sterilized?
Mucus on broncho protects the microbes underneath and interferes with sterilization process.
Define sterilization.
kills everything, spores and vegetative.
What’s the difference between disinfect and antiseptics?
Both kill vegetative. But disinfect is not safe for skin.
What are the 3 classifications of disinfectants based on their mode of action?
Modification:
- Lipids.
- Proteins
- DNA
What are the disinfectants that modify lipid layer? Examples.
- Alcohol
- Detergents
- Benzalkonium chloride - Phenolic compounds
- Hexaclorophene
- Lysol
What are the disinfectants that modify proteins? Examples.
How?
- Sulfur Linkage
- Cholorine (Clorox)
- Iodine (Tincture, Iodophores) - Hydroxy methyl alkylates proteins
- hydrogen peroxide
- formaldehyde
- glutaraldehyde
- ethylene oxide - Heavy metals
- Thiomerosal
- Merbromine
- Silver Nitrate
- Gonococcal ophthalmia neonatorum
What types of microbes can evade hydrogen peroxide?
Those that produces catalase, which degrades hydrogen peroxide to water
What are the disinfectants that modify proteins? Examples.
- Gentian violet
- Malachite green in lowenstein-jensen media
Positive charge will bind to negative charge DNA and deactivate DNA.
What are the physical agents?
- Heat
- Moist heat
- Dry heat - Filtration
- Radiation
What are the 3 settings of autoclave?
- 120C
- 15 pounds pressure
- 15 minutes
What is spore testing?
To ensure autoclaving is effective.
Put a tube of clostridium botulism into the autoclave with the equipment. Then incubate to see if it germinates. If it doesn’t, autoclave was effective.
Name an example of dry heat.
Pasteurization.
What is pasteurization?
60C for 30 minutes to kill vegetative forms.
- Salmonella
- Mycobacterium bovis
What does filtration do?
Removes endotoxin.
What is UV radiation? Ionizing radiation?
UV: Thymine dimerization and inactivates DNA.
Ionizing: Generates hydroxyl radicals that breaks covalent bonds in the DNA.
Who found Penicillin?
1928 - Alexander Fleming found in bread mold.
1939 - Florey, Chain, and Associates isolated and synthesized.
1940s - available for general use in US.
Staphylococcus aureus is what gram bact?
Gram positive.
Chlamydia is what gram bact?
Gram negative.
Mycobacterium tuberculosis is what?
Non reactive. Acid-fast bacteria. TB.
Haemophilus influenzae is what gram bact?
Gram negative. Capsule is virulent. LPS causes sepsis.
Mycoplasma pneumonia causes?
Atypical form of pneumonia.
A person who has compromised immune system should be given bacteriostatic of bactericidal?
Bactericidal, must kill the microbes since immune isn’t strong enough to kill.
Chloroarmphenicol Erythromycin Clindamycin Sulfonamides Trimethoprin Tetracyclines
Examples of bacteriostatic or bactericidal?
Bacteriostatic.
Aminoglycosides Beta-lactams Vancomycin Quinodones Rifapin Metronidazole
Examples of bacteriostatic or bactericidal?
Bactericidal
Beta-lactams does what to microbe?
Interferes with cell wall synthesis, causes cell lysis of bacteria.
What bacteria are resistent to beta-lactams?
Those producing beta-latanase, which would degrade beta-lactams.
What are examples of beta-lactams?
Penicillin
Cephalosporin
Imipenem
Clavulanate
Mechanism of glycopeptides?
Vancomycin prevents cell wall cross-linking enzyme to work effectively. Cell wall synthesis is disrupted.
How can a cell be vancomycin resistant?
If they have D-lactate, making vancomycin not fit well. Therefore, the cell wall cross-linking enzyme works fine and cell wall is synthesized.
Mechanism of aminoglycosides?
Binds to 30s, making wrong amino acid to join translation. This is irrversible.
What are examples of aminoglycosides?
Kanamycin A
Gentamicin C1a
Neomycin B
Streptomycin
What are the adverse effects of aminoglycoside?
- Ototoxicity
- reversible vestibular
- irreversible suditory - Nephrotoxicity
- reversible - NMJ blockade
- a high dose - Pregnancy Cat C
- 8th nerve
T/F: Aminoglycoside is almost always used along with a cell-wall synthesis inhibitor.
True.
What is the mechanism of Tetracycline?
Blocks mRNA and prevents amino acid from adding to protein peptide.
Bacterial static.
What is the adverse effect of tetracycline?
Yellow and degrading teeth.
What is mechanism of macrolide?
Bind to 50S and blooc translocation step, peptide bond formation. Bacterialstatic.
What is the adverse effects of macrolide?
- Nausea, vomiting, diarrhea
- Abdominal pain
- Liver toxicity (estolate related)
- *Erythromycin inhibits p-450 (drug interactions) and increase QTc
What is mechanism of fluoroquinolones?
Inhibits DNA gyrase and topoisomerase IV.
Bactericidal.
What are the adverse effects of fluoroquinolone?
- Tendon rupture
- Affects cartilage of children under 18 yo.
- Pregnancy Category C
- Seizures, prolonged QT.
- Dizziness, confusion
- Photosensitivity.
What is mechanism of trimethoprim-sulfamethoxazole?
Inhibits folic metabolism, affecting nucleic acid biosynthesis.
What microbe increasing resistant to sulfamethoxazole-trimethoprim combo? What is it most effective?
S. pneumoniae is increasing resistent, therefore limited use for respiratory infections.
Excellent for UTI and bacterial diarrheas.
Surgical instruments that are sensitive to heat sterilization are sterilized by ____ _____?
Ethylene oxide.
These antibiotics work against what?
- Bacitracin
- b-lactams
- fosformycin
- glycopeptides
Cell wall construction.
These antibiotics work against what?
- colisin
- polymycin B
Structure and function of the cell membrane.
These antibiotics work against what?
- aminoglycosides
- lincosamide
- macrolides
- tetracyclines
Protein synethsis.
These antibiotics work against what?
- Rifampin
RNA
These antibiotics work against what?
- Quinolones
- Nitrofurantoin
- Nitrimidazole
Structure and function of DNA.
These antibiotics work against what?
- Trimethoprim
- Sulfonamides
Folic Acid Synthesis.
