bacte (controlling microbial growth)

Sterilization

purpose is to destroy all microorganisms and their spores on inanimate objects

disinfectant

purpose is to destroy or irreversibly inactivate microorganisms (but not their spores) on inanimate objects

antiseptic

chemical germicide for use on the skin or tissues and should not be vsubstituted for disinfectant

bacteriostatic

inhibits/ suppresses growth of bacteria

bactericidal

kills bacteria

sterilization by heat

Kills microorganisms by denaturing/coagulating their proteins and enzymes

Thermal Death Time (TDT)

minimum time it takes to kill a population of microbes at a specific temperature

Thermal Death Point (TDP)

lowest temperature that is required to kill a population of microbes when applied for a specific time.

Decimal Reduction Time (DRT)

Time in minutes at which 90% of bacteria is killed within a given period of time. canning industru

Hepatitis virus

can survive up to 30 mins of boiling

Endospores

can survive up to 20 minutes of boiling

boiling

Kills vegetative forms of bacteria (water-borne), most virus, and fungi within 1 minute

dry heat

• Use primarily on glassware, metals and fatty substance which are not permeable to water

• Temperatures of about 160C for 60minutes – necessary to kill most spores

• ex: hot air oven

autoclave

• most effective method of sterilization

• Use to sterilize culture media and surgical supplies

Fractional sterilization

Tyndallization is AKA

• the steaming process performed at 100°C done in steam sterilizer for 15-20 minutes followed by incubation at 37°C overnight and this cycle is repeated for successive 3 days

• use to kill spores

• uses Arnold sterilizer

• process of food preservation in which packaged and unpacked foods (e.g.,milk and fruit juices) are treated with mild heat, usually to less than 100 °C (212 °F), to eliminate pathogens and extend shelf life

• destroys or deactivates microorganisms and enzymes that contribute to food spoilage or the risk of disease

High-temperature short-time (HTST) pasteurization

for milk; (71.5 °C (160.7 °F) for 15 seconds) which ensures safety of milk and provides a refrigerated shelf life of approximately two weeks

Ultra-high-temperature (UHT) pasteurization

milk is pasteurized at 135 °C(275 °F) for 1–2 seconds, which provides the same level of safety, but along with the packaging, extends shelf life to three months under refrigeration

filtration

• Use if heat is not feasible (some carbohydrates solutions, serum, body fluids)

• removes microbes by passge of liquid or gas through a screen like material with small pores

High Efficiency Particulate Air Filter (HEPA)

use in operating rooms to eliminate bacteria; mostly filters particles that are 0.3um; capture pollen, dirt, dust, moisture, bacteria (0.2–2.0 μm), viruses (0.02–0.3 μm), and submicron liquid aerosol (0.02–0.5 μm)

bacteriostatic

usually inhibit or stop microbial growth and proliferation but often do not kill bacteria

alcohol

• works by denaturing and coagulating proteins, disrupting their cell wall, and killing them; dissolves lipid membranes

• highly efficient against viruses

H2O2, K-permanganate

what are the oxidizing agents

soaps

disrupt the chemical bonds that allow bacteria, viruses and grime to stick to surfaces, lifting them off the skin

antimicrobial agents

Any chemical use to treat an infections either by inhibiting or killing pathogens