Microbial Growth Control (Burton's Microbiology for the Health Sciences)

sterilization

the complete destruction of all forms of microbial life, including endospores

commercial sterilization

refers to the sufficient heat treatment to kill endospores of Clostridium botulinum in canned goods

disinfection

the destruction of vegetative pathogens usually on inanimate surfaces/ objects

antisepsis

the destruction of vegetative pathogens on living tissue

degerming

the mechanical removal of microbes from a limited area

sanitation

refers to the application of treatment intended to lower microbial counts to safe public health levels

biocide/ germicide

a substance that kills microorganisms but has certain exceptions such as the endospores

antibiotic

an agent produced by microorganisms that inhibit or kill other microorganisms

microbiostatic agent

a drug or chemical that inhibits the growth and reproduction of microorganisms

bacteriostatic agent

an agent that inhibits the growth and reproduction of bacteria

sterile technique

a technique practiced when it is necessary to exclude all microorganisms from a particular area for the area to be sterile

Heat sterilization

an efficient and inexpensive method of sterilization of those inanimate objects and materials that can withstand high temperatures

thermal death point

the lowest temperature at which all the microbes in a liquid suspension will be killed in ten minutes

thermal death time

the minimal length of time in which all bacteria will be killed at a given temperature

decimal reduction time

time in minutes at which 90% of bacteria at a given temperature will be killed and is usually used in the canning industry

moist heat sterilization

a method of sterilization that causes proteins to coagulate because cellular enzyme proteins are inactivated by moist heat, leading to cell death

boiling

a method of moist heat sterilization that kills vegetative forms of bacterial pathogens, viruses, fungi, and their spores within 10 minutes

pasteurization

the process by which heat is applied to food and beverages to kill pathogens and extend their shelf life

classic method of pasteurization

an example of this method of pasteurization is when milk is exposed to 63°C for 30 minutes

high-temperature short-time pasteurization

an example of this method of pasteurization is when milk is exposed to 72°C for 15 seconds

ultra-high temperature pasteurization

an example of this method of pasteurization is when milk is treated at 140°C for 3 seconds and then cooled very quickly in a vacuum chamber

direct flaming, incineration, and hot air sterilization

what are the 3 methods of dry heat sterilization?

direct flaming

a method of dry heat sterilization that is used to sterilize inoculating loops and needles

incineration

a method of dry heat sterilization where ashes are burned and is an effective means of destroying contaminated disposable materials

hot air sterilization

a method of dry heat sterilization where objects are placed in an oven and requires 2 hours at 170°C for sterilization

filtration

a method used to sterilize heat sensitive materials like vaccines, enzymes, antibiotics, and culture media

high efficiency particulate air filters (HEPA)

used in operating rooms and burn units to remove bacteria from air with an efficiency of 99.97% in particles 0.3 um or greater

membrane filter

filter that is in uniform pore size and are usually used in industry and research

refrigeration

a method that reduces the metabolic rate of most microbes so they cannot reproduce or produce toxins where the temperature is set from 0°C to 7°C

lyophilization or freeze drying

most effective method for long term preservation of microbial culture and water is removed by high vacuum at low temperature

protein denaturation

what is the method of action for high pressure method of microbial control?

ionizing radiation

high energy radiation that have a short wavelengths of less than 1 nanometer, is bactericidal and is used to sterilize pharmaceutical and disposable medicine supplies

nonionizing radiation

a type of radiation method that has a wavelength longer than 1 nanometer, damages DNA, and is used to disinfect operating rooms, nurseries, and cafeterias

microwave radiation

a type of radiation method that has a wavelength ranging from 1mm to 1m and may kill vegetative cells in moist foods

chemical disinfection

refers to the use of chemical agents used to inhibit growth of pathogens, either temporarily or permanently

use-dilution test

a test used to determine bacterial survival in the manufacturer's recommended dilution of a disinfectant

use-dilution test

a test used to evaluate the effectiveness of agents against viruses, endospore-forming bacteria, mycobacteria, and fungi

the disk-diffusion method

a method of evaluating a disinfectant that measures the zone of inhibition

phenol

a type of disinfectant that is called a carbolic spray and is used in some throat sprays or lozenges for its local anesthetic effect, was also first used by Lister as a disinfectant

phenolics

the chemical derivative of phenol that destroys plasma membrane and denature proteins

cresol

derived from coal tar, stable, able to persist for long times after applied, and remains active in the presence of organic compounds

phenol coefficient

refers to the measure of disinfecting power of chemical agent through comparison with phenol

bisphenols

a type of disinfectant which are derivatives of phenol that contain two phenolic groups connected by a bridge

chlorhexidine

a member of biguanide group with a broad spectrum of activity and is used for surgical hand scrubs and preoperative skin preparations in patients

essential oils

a type of disinfectant that is a mixture of hydrocarbons extracted from plants

iodine

a type of disinfectant which mode of action is to combine with certain amino acids to inactivate enzymes and other cellular proteins

iodophors

compounds with iodine that are slow releasing, takes several minutes to act and is used as skin antiseptic in surgery

chlorine dioxide

a gaseous form of chlorine used to kill endospores of the anthrax bacterium

alcohol

a type of disinfectant that is used to mechanically wipe microbes off skin before injections and are not good for open wounds due to the coagulation of proteins under which bacteria continues to grow

silver nitrate or 1% silver nitrate

it is used to protect infants against gonorrheal ophthalmia neonatorum

copper

is used to kill algae in pools and fish tanks

selenium

used in dandruff shampoos and for fungal infections

soaps

have limited germicidal reactions but assist in the removal of microorganisms through scrubbing

aldehydes

a type of disinfectant that inactivates proteins by forming covalent crosslinks with several functional groups

ethylene oxide

kills all microbes and endospores but requires exposure of 4 to 18 hours

ozone

it is a highly reactive form of oxygen that is more effective killing agent than chlorine but is less stable and more expensive

hydrogen peroxide

it is used as an an antiseptic and is usually used in the food industry and in disinfecting contact lenses

benzoyl peroxide

it is used in acne medications

peracetic acid

it is used widely in disinfection of food and medical instruments because it does not leave toxic residues, kills bacteria and fungi in less than 5 minutes and kills endospores and viruses within 30 minutes

plasma sterilization

a type of disinfectant that inhibits vital cellular functions and is useful for tubular medical instruments

superficial fluids

a type of disinfectant that inhibits vital cellular function and is useful for sterilizing organic medical implants

glutaraldehyde or 2% solution of glutaraldehyde

an aldehyde that is bactericidal, tuberculocidal, viricidal in 10 minutes and sporicidal in 3 to 10 hours and is commonly used to disinfect hospital instruments

quaternary ammonium compound

a surface-active agent that is effective against gram-positive bacteria and destroys fungi, amoeba, and enveloped viruses

hexachlorophene

it is the main ingredient of Phisohex and is used for surgical and hospital microbial control procedures

zinc chloride

it is under the heavy metals disinfectant that is used in mouthwashes