Methods of Microbial control

1. sterilization- everything including endospores.

2. disinfection- killing organisms (vegetive cells)/ everything but endospores.

3. Decontamination- lowering microlevels to “safe”

-cidal means to kill ex: bactericidal

-static/stasis- not killing but inhibiting Ex: bacteriostatic

Physical Methods

1. Temperature: Heat & Cold

Heat goes into 2 sections dry and moist.

Dry- 1. incineration (sterilization) 2. Hot air (sterilizations) 160c-2hr/170-1hr

Moist- 1. pasteurization- foods (Decontamination) 2. boiling 100c - 30 mins (disinfection) 3. auto clave- 121c, 15psi (pounds per square inch) {for pressure rate} 15 minutes

*moist/ steam can penetrate cells which is more effective.

Cold- fridge and freeze

cold temps don’t kill, they just inhibit them.

It can cause freezer burn from the ice crystals can poke bacterial pockets and destroy them.

2 Radiation

ionizing and non-ionizing

ionizing ex: gamma rays and x-rays.

non-ionizing ex: UVrays. Uvc-265/UV cannot penetrate through layers.

thyme-thymine dimers- (Longer we expose dimers, the harder for the cell to fix it)

cell death- unable to reproduce/gives up.

3 Filtration

liquid, gases, heat-sensitive medications.

0.45nm- used for bacteria

0.22nm- viruses

^^^ the size of the pore.

Chemical Methods

1. Disinfectants & Antiseptics (non-living vs living):

   Hydrogen & mouthwash are examples of Antiseptics.

2. Antibiotics & Antimicrobials:

   Antibiotics- how it is made is that it has to be created from nature.

   Antimicrobials- has to be made in a lab/ partially or fully synthetic.

MHA plate- Muller Hinton Agar: a lawn of bacteria covers the whole plate of bacteria to create a film.

Soap vs Hand sanitizers

Soap: surfactants- reduces surface tensions and friction. Wash for 30 seconds for clean hands.

Hand sanitizers: At least 70% of alcohol to work. Alcohol dissolves lipids & dries them out.