Ch. 13 controlling microbes in environment

Antiseptic

Antimicrobial chemicals that are safe for use on living skin and/or tissues

Aseptic

Prevents contamination of sterile surfaces, free from pathogens

degerming

Removing microorganisms with soap

Disinfection

Inactivates most microbes on the surface by using anti - microbial chemicals and/or heat

Pasteurization

Heat treatment of perishable fluids followed by rapid chilling to inhibit growth of survivors and germination of spores, prevents infection/spoilage

Sanitation

Surfaces are cleaned well enough to reduce microbes to levels that are safe by public health standards

Sterilization

Complete killing of cells, spores, viruses

How does a fungicidal differ from fungistatic agent?

Fungistatic - inhibit fungi

Fungicidal - kill fungi

ways antimicrobials work

prevent cell wall synthesis

Prevent protein synthesis

Makes holes in membrane

Inhibit metabolic pathways

Ideal antimicrobial

Target only the microorganisms but not the patient, have little to no side effects

factors affecting efficacy of antimicrobials

Antibiotic concentration

How body responds to antimicrobial

How does heat kill microbes?

Denatures microbes proteins, including enzymes needed for all metabolic reactions

How does desiccation differ from lyophilization?

Lyophilization uses vacuum and cold temp

desiccation uses heat.

Lyophilization retains better shape and rehydrates faster.

How does osmotic pressure stop microbial growth?

Cells shrink at high osmotic pressure

Cells burst at low osmotic pressure

What type of microbe survive well with high osmotic pressure?

Halophiles

How does radiation kill microbes?

The formation of thyminedimers in DNA, leading to lethal mutations in the microbes