Lecture 6 Flashcards
Where does antisepsis inhibit the growth of pathogens
Surfaces of living tissue
Where does disinfection inhibit the growth of pathogens
Inanimate surface
What are the three ways to sterilize
Heat, Radiation, Filters
What are the effects of heat sterilization on the pathogen cells
· Denatures Macromolecules
· Lose Structure and Function
Why does the autoclave use steam to sterilize materials
· Cell Penetration Power
· Reduce Resistance of Spores
What dDoes Not Kill All Microbes, But Reduces Their Number
Pasteurization
What type of pasteurization Reduces Pathogenic Bacteria and Extends Shelf Life
Flash pasteurization
These are effects of what type of sterilization?
· Energy that Modifies or Breaks DNA (Ultraviolet)
· Radicals that Disrupt Proteins and Lipids (Ionizing)
Radiation Sterilization
Advantages
· Practical and Safer
Disadvantages
· Surface Sterilization Only
· Cannot Penetrate Solid Objects
What type of radiation sterilization is this?
UV Radiation
What type of radiation sterilization is this?
Effects
· Exposure to Electromagnetic Radiation
· Radiation Particles Create Radicals (H·, OH·)
Advantages
· Cold Sterilization
· Penetrate Solids and Liquids
Disadvantages
· Dangerous, Requires Special Equipment
Ionizing Radiation
What type of radiation sterilization is this?
Effect
· Sterilization without Heat
· Filters Exclude Passage of Microbes
Advantages
· Useful for Heat-Sensitive Items · Very Safe
Disadvantages
· Limited Application (Liquids, Gases)
Filter sterilization
· Borosilicate (Glass) Fibers
· Microbes Trapped in Fiber Network
These make up what kind of filter in filter sterilization?
Depth filter
· Strong Polymers (e.g. Cellulose)
· Microbes Trapped on Surface
These make up what kind of filter in filter sterilization?
Membrane filters
· Polycarbonate Film
· Microbes Trapped on Surface
These make up what kind of filter in filter sterilization?
Nucleopore filters
What type of chemical growth control…
· Bind to Ribosomes
· Prevent Protein Synthesis
Bacteriostatic (stop growth)
What type of chemical growth control…
· Cells Dead but Intact
· Bind to Specific Cellular Targets
Bacteriocidal (kill cells)
What type of chemical growth control…
· Cells Lyse and Are Destroyed
· Target Cell Wall and Membranes
Bacteriolytic (kill cells)
… Kill All Microbial Cells + Endospores
Sterilants
… Kill All Microbial Cells, But Not Endospores
Disinfectants
… Lead the way to synthetic drugs
· Early 1900s German Scientist · “Magic Bullet”
Selective Toxicity
· Inhibit or Kill Microbial Pathogens · Do Not Harm Human Cells
Paul Ehrlich
Isoniazid, Quinolones, and Sulfa Drugs are all examples of …
synthetic drugs
What type of macrocodes Interfer with Protein Synthesis
Erythromycin
Azidothymidine is a type of … drug
Antiviral
Ergosterol is a type of … drug
Antifungal
These are mechanisms of …
(1) Impermeability: ▼porin channels
(2) Efflux
(3) Inactivation: beta-lactamase
(4) Mutation in Target: PBP mutation
(5) Absence of Target
(6) Alternative Biochemical Pathway
Antibiotic resistance
In antibiotic resistance evolution looks at
origins of resistance
In antibiotic resistance ecology looks at
spread of resistance
In antibiotic resistance economics looks at
dealing with resistance
T or F
there are no universal antibiotics
True
What is an Alternative Function of Antibiotics
signaling molecules
· Sub-Inhibitory Concentrations
· Alter Gene Expression
- Virluence, colonization, motility, biofilm formation
These are other functions of …
Antibiotics: signal molecules
· Catabolism of Penicillin
· Beta-lactamaseàC/N source
This is the food source for …
Antibiotics: signal molecules
How many patients need vs. receive antibiotic treatment
· 20% of Patients
- Need Antibiotic Treament
· 80% of Patients
- Receive Antibiotic Treatment
· MRSA
- Methicillin-Resistant Staphylococcus aureus
These are known as … pathogens
invincible
In the case of non-medical antibiotic overuse what percentage used for Livestock/Agriculture
· 50-70% of Antibiotic Used for Livestock/Agriculture
- Feed Supplement
- Aquaculture
- Fruit Production
What is the Economic Paradox of Antibiotics
· Low Return on Investment · Loss of Value over Time
What does Reversing Antibiotic Resistance entail
·êUsage =êSelection =êPrevalence of Resistance · Requires a Large-Scale, Coordinated Effort
Describe Narrow Spectrum Antibiotics
· Hinges on rapid, accurate diagnosis
Describe Broad Spectrum Antibiotics
· New applications?
· Pre-treatment for FMT?
What are the five aves in the search for new antibiotics
1) New Analogs of Exisiting Compounds
2) Computer Drug Design
3) Natural Products
4) Drug Combinations
5) Bacteriophage Therapy
