Chapter 7 Flashcards
Sepsis
microbial contamination
Asepsis
absence of significant contamination
biocide/germicide
kills microbes
bacteriostasis
inhibits growth of microbes, but doesn’t kill them
After the removal of a bacteriostatic agent, microbial growth _______________.
can resume
What are three ways that control agents affect microbial cells?
- Alter membrane permeability 2. Damage proteins 3. Damage nucleic acids
4 Factors that Influence the Effectiveness of Control Treatment
- Number of microbes 2. Amount of time exposed to treatment 3. Environment 4. Microbial Characteristics
Why does the number of microbes affect the effective on control treatment?
takes longer to kill them all
Examples of Environmental Influences on the effectiveness of control treatments:
organic matter, temperature, biofilms
What microbial characteristics makes it harder to kill microbes?
Being mycobateria, or having endospores
Sterilization
complete elimination of all living organisms, including endospores
Disinfection
Killing or removal of pathogens from inanimate objects; typically does not kill spores
Antisepsis
Killing or removal of pathogens from living tissues; typically does not kill spores
Sanitation
reduction of microbes on eating and drinking utensils to safe levels
4 Types of Physical Control
high temperature, low temperature, filtration, radiation
_____ heat is more effective than ___ heat
Moist; dry
Killing spores and thermophiles usually requires _____ heat and _____ temperature.
high; high
How does an autoclave kill microbes?
Denatures proteins
Commercial Sterilization
enough heat to kill Clostridium botulinum endospores; not completely sterile
Botulism
Clostridium botulinum; rare but serious paralytic disease caused by a nerve toxin
Pasteurization
reduces spoilage organisms and pathogens