killing bacteria Flashcards
(25 cards)
What is sterilisation?
Elimination of all organisms
Sterilisation is crucial for ensuring that no viable microorganisms remain in a given environment or on a surface.
Define pasteurisation.
Heat destruction of vegetative cells
This process is often used in food safety to kill harmful microorganisms.
What is disinfection?
Elimination or reduction of harmful microorganisms
Disinfection is less comprehensive than sterilisation, focusing on reducing pathogens to safe levels.
What does aseptic mean?
Free from contamination caused by harmful bacteria, viruses, or other microorganisms
Aseptic conditions are vital in medical and laboratory settings.
What is the Minimum Inhibitory Concentration (MIC)?
The lowest concentration of an antimicrobial that will inhibit the visible growth of a microorganism after overnight incubation
MIC is a key measure in determining the efficacy of antibiotics.
What are the heat sterilisation methods?
- Dry heat: 160°C for >2 hours
- Steam: 121°C at 15 lbs/in for 20 mins
These methods are standard practices in sterilisation protocols.
What are some chemical sterilisation methods?
- 500 mg/L ethylene oxide for 4 hours
- 2.5% Sodium hypochlorite or 2.2% glutaraldehyde for 24 hours
Chemical sterilants are often used for heat-sensitive instruments.
What radiation method can be used for sterilisation?
High intensity UV for 30-60 mins
UV radiation is effective in killing microorganisms on surfaces.
What is an ideal property of an antibiotic?
Must impede the growth of pathogenic bacteria
This property is essential for the effectiveness of antibiotics in treating infections.
Differentiate between bacteriostatic and bactericidal.
Bacteriostatic inhibits growth; bactericidal kills bacteria
Understanding the difference is important for selecting appropriate antibiotic therapy.
What is selective toxicity?
The ability of an antibiotic to target bacterial cells without harming host cells
Selective toxicity is critical for minimizing side effects during treatment.
What factors influence antibiotic pharmacokinetics?
- Bioavailability
- Stability
- Low cost
These factors determine how well an antibiotic performs in the body.
What are the targets of antibiotics?
- Cell Membrane
- Cell Wall
- Nucleic acid synthesis
- Protein synthesis
- Bacterial metabolism
Targeting these areas disrupts bacterial functions and leads to cell death or growth inhibition.
True or False: Antibacterials are the same as other types of pharmaceuticals.
False
Antibacterials are specifically designed to treat bacterial infections and have unique properties.
What is the average timeframe for speciation in diagnostics?
48 hours
Rapid diagnostics are crucial for timely treatment decisions.
What is the significance of the AcrAB/TolC system?
It is an efflux transporter that helps bacteria resist antibiotics
Understanding this system is important for addressing antibiotic resistance.
How does antibiotic resistance spread?
Through selection of resistant bacteria, not people
This highlights the importance of responsible antibiotic use to prevent the spread of resistance.
What are some common problems associated with aminoglycosides?
- Variable toxicities
- Resistance
Aminoglycosides are effective but can have significant side effects.
Fill in the blank: The average time to first incidence of resistance is approximately _______.
6 months
This rapid emergence of resistance poses challenges for antibiotic treatment.
What are the two main classes of nucleic acid synthesis inhibitors?
- Rifamycins
- Quinolones
These classes target bacterial RNA and DNA synthesis, respectively.
What is the role of ribosomal structure in protein synthesis inhibition?
Differences between prokaryotic and eukaryotic ribosomes allow selective targeting
This selectivity is crucial for antibiotic effectiveness.
What is the mechanism of action for β-Lactams?
Inhibit cell wall synthesis
β-Lactams are a widely used class of antibiotics.
What are the consequences of antibiotic-associated diarrheal disorder?
Can take months or years for balance to be re-established
This condition can lead to significant health issues following antibiotic treatment.
What is the effect of prolonged antibiotic use?
Determining toxicity becomes complicated
Long-term use can lead to cumulative side effects.
