11) Physical and Chemical control of Microbes Flashcards
__________ is the physical, chemical, mechanical methods to destroy, reduce microbes in a given area
decontamination
The hardest bacteria to kill is?
Bacillus cereus
The easiest bacteria to kill is?
Bread mold(Rhizopus)
________ is permanent loss of reproductive capability, even under optimum growth conditions
microbial death
Microbial death is hard to detect because microbes often do not show _________ to begin with
vital signs
Modes of action of antimicrobial agents fall into four categories:
- cell wall
- cell membrane
- _______ synthesis
- alter _______ function
nucleic acid
protein
_________ mode of action causes the cell wall to become fragile and will lyse(explode) by osmotic pressure
Cell wall
________ mode of action causes the cell loses its selective permeability and cannot prevent the loss of vital molecules or the entry of damaging chemicals
Cell membrane
________ synthesis mode of action binds to DNA, causing mutations in DNA, preventing transcription and translation
Nucleic acid
Altering ________ function mode of action denaturalizes protein and prevents from working (meaning no chemical reactions)
protein
6 factors that govern the effectiveness of a particular agent
- Exposure time
- concentration of the agent,
- number of _________
- pH of the environment
- modes of ______
- present of solvents or interfering _______
organisms
action
substances
Physical _______ are methods of physical control
agents
When using dry heat at moderate to high temperature dehydration alters _______ structure and incineration occurs
protein
When using moist heat at lower temperatures with a shorter exposure time _______ and denaturation of proteins occurs
coagulation
What kind of cells does moist heat kill?
Vegetative cells
Autoclaving uses what type of microbial control?
Sterilization
Autoclaving sterilization is used for?
Media, use media, glassware, some surgical equipment
Auto cleaning should heat objects up to 121 degrees Celsius at 15 PSI for how long?
10 to 40 minutes
Intermittent sterilization is equal to?
tyndallization
What type of method of microbial control is tyndallization?
Disinfectant
tyndallization was developed by?
John Tyndall
Tyndallization is exposed to what type of steam?
Free flowing
Tyndallization is heated to 100 degrees Celsius for 30 to 60 minutes on three successive days with what in-between?
Incubation periods
Tyndallization is used for?
Sensitive culture media ( sera, egg, carbohydrates)
During pasteurization heat is applied to kill potential agents of infection and spoilage without destroying the food flavour, but foods are not…?
Sterile
High-temperature short- time(HTST) is heated to what temperature?
72 degrees Celsius for 15 SEC
High-temperature short- time(HTST) is used for?
Milk (flash method)
Ultra high temperature method (UHT) is heated to what temperature?
138 degrees Celsius for 2 SEC
Ultra high temperature method (UHT) is used for?
Organic milk, small serving sizes of Creamer that are commercially sterile
Is pasteurization sterilization?
No
Pasteurization kills what type of microbe?
Non-spore forming pathogens
Pasteurization is used for?
Milk, juices, cream, alcoholic beverages
What method of microbial control is boiling water?
Disinfection
When using boiling water as a disinfection method of microbial control should heat the water to what temperature?
100 degrees Celsius for 30 minutes
Boiling water/ disinfection is used for?
Unsafe drinking water, home canning, materials for baby
What method of microbial control is a dry oven?
Sterilization
When using a dry oven as a sterilization method of microbial control the temperature should be at?
150 - 180 degrees Celsius for 2-4 hours
Dry oven sterilization is used for?
Glassware, powders, oils, metals
What method of microbial control is incineration?
Sterilization
Incineration sterilization when using a bunsen burner at 1870 degrees Celsius is used for?
Inoculating needles and loops
Incineration sterilization when using a furnace incinerator should be heated to 800 to 6500 degrees Celsius and used for?
Medical waste
Microbiostatic means?
Slows the growth of microbes
What does refrigeration at 0-7 degrees Celsius cause microbes to do?
Slows the growth of microbes
Where is using refrigeration at 0- 7 degrees Celsius to slow the growth of microbe used?
Home kitchens and labs
Refrigeration at 0-7 degrees Celsius is used to?
Presume foods, medical supplies, and cultures
What does freezing microbes at less than 100 degrees Celsius do?
Stops the growth and kills some susceptible organisms
Freezing microbes below zero degrees Celsius is used in home kitchens and laboratories to…?
Store foods and some microorganisms
What Is dessication?
Gradual removal of water from cells that leads to metabolic inhibition
Is desiccation and effective microbial control?
No because some cells retain ability to grow when water is reintroduced.
Desecration is used for foods such as?
Raisins, Prunes, jerky
Lyophilization is…?
Freeze drained or “snap-frozen”
Lyophilization combines freezing and..?
cold
Lyophilization is effective for?
Controlling microbial growth
Lyophilization is used in the food industry and the lab for?
Long-term storage of microbial cultures
Radiation waves or particles bombard molecules in a…?
cell
Radiation damages molecules, but the most sensitive is…?
DNA
Radiation creates bonds or causes breakages known as…?
mutations
Does ionizing radiation create ions?
yes
Does nonionizing radiation create ions?
No
Ionizing radiation is deep penetrating and has energy to cause electrons to…?
Leave their orbit, and breaks DNA
Gamma rays are…?
x-rays, cathode rays
Are gamma rays hot or cold sterilization?
Cold
Gamma rays sterilized materials that are sensitive to…?
Heat or chemicals
Gamma rays are used to cut down microbial loads in anything medical related that can be…?
reused
Gamma rays are used in food such as…?
Flower, pork, ground beef, fruits, vegetables and juices
UV light create pyrimidine dimers which interfere with…?
replication
Ultraviolet ray (UV) range in wavelengths from…?
100nm- 400nm
Most lethal wavelength of ultraviolet rays (UV) is…?
260nm
Germicidal lamp that meets a specific wavelength of UV is placed on…?
Ceilings, upper part of walls or air ducts.
A germicidal lamp is used for…?
Hospital rooms, operation rooms, schools, nursing homes, food processing plants, slaughterhouses, wastewater
Filtration involves straining a liquid or air through a layer of material with openings large enough for liquid or air to pass through but too small for…?
Microorganisms
A depth filter includes..?
Sand, charcoal, diatomaceous earth
A membrane filter includes…?
cellulose acetate or plastic
Depth filters and membrane filters have a poor diameter of…?
8 - .02mm
HEPA filters stand for…?
High efficiency particulate air
HEPA filters filter bacteria, endospores, and many viruses with a pore diameter of…?
.3mm
HEPA filters used in…?
Cars, airplanes, home, biological safety cabinets, as well as hospital settings such as surgical suits burn units isolation units
Membrane filters filter water with a pore diameter of…?
.2mm
Membrane filters filter heat sensitive media and…?
Beer and wine
High level germicides kill…?
Endospores
Intermediate level germicides kill…?
Fungal spores, not endospores
Intermediate level germicides disinfect devices that come into contact with…?
Mucus membranes
Low level germicides eliminate only…?
vegetative bacteria, fungal cells, some viruses
Low level genocides clean services that…?
Skin touch
Chemical agents occur in what states…?
Liquid , gas, or solid
Chemical agents vary from antiseptics to disinfectants to…?
Sterilants
If a solid chemical agent may be dissolved in water it is…?
Aqueous
If a solid chemical agent may be dissolved in alcohol it is…?
tincture
Phenol is also known as…?
Carbolic acid
Joseph Lister (1860’s) used phenol to clean…?
Surgical hands and wounds
Acrid is a poisonous compound derived from distilling coal tar and is an irritant of the…?
Skin
Joseph Lawrence (1836-1909) developed listerine and oral antiseptics made with…?
Alcohol related compounds
Products of phenol are called?
Phenolics
Phenolics disrupt cell walls and membranes and…?
Precipitate proteins
Phenolics a little to intermediate level that is bactericidal, fungicidal, virucidal but not…?
Sporicidal
Phenolics are used for…?
Antibacterial soaps, disinfectants, mouthwashes, throat lozenges
And example of phenolics is…?
Lysol
Chlorhexidine is a chemical agent that is a compound and…?
2 phenolic rings
Chlorhaxidine is also called…?
Chloheidine gluconate
Chlorhaxidine is a surfactant and protein denaturant with broad…?
Microbicidal properties
Chlorhaxidine is what type of solution?
Alcoholic or aqueous
Chlorhaxidine is used to control MRSA and Acinetobacter outbreaks in…?
Hospitals
Chlorhaxidine is used for…?
Hand scrubbing, skin surgery sites, injections, wounds, neonatal wash, also used in a preservative and eye solutions
Alcohols are used to incinerate enveloped…?
Viruses
Ethyl alcohol or ethanol is also called…?
Grain alcohol
Isopropyl alcohol or propanol is also called…?
Rubbing alcohol
Alcohols have what type of functional group?
OH
Alcoholics are a intermediate level chemical agent that act as surfactants to dissolve…?
Membrane lipids and coagulating proteins of vegetative bacterial cells and fungi
Alcohols are used for…?
Swab skin, before injection, hand sanitizers, disinfect surfaces
Hydrogen peroxide(H2O2) is a colorless liquid that decomposes in…?
Presence of light or metals
What percentage of hydrogen peroxide is potent enough to sterilize(sporicidal)?
6-25%
Hydrogen peroxide is used for…?
Antiseptic for skin, wound, bed sore, mouthwash, toothache, contact lens cleaner, surgical implants, plastic equipment
The active ingredients in nearly one third of all antimicrobial chemicals currently being marketed include?
Halogens
Halogens include…?
Fluorine, bromine, chlorine, iodine
The two most commonly used halogens are…?
chlorine and iodine
What does chlorine do to cells?
Denaturalizes proteins by disrupting disulfide bonds
The chemical agent chlorine is what level of a chemical agent?
Intermediate level
Chlorine is less effective if exposed to…?
Light, alkaline pH, organic materials
Two major forms of chlorine are?
Liquid and gas
Liquid chlorine is the chosen cleaner to treat what bacteria?
C. diff
Another term for liquid chlorine bleach is?
Hypochlorites
Liquid chloramine is used to treat?
Water
Cl2 or chlorine gas is used to treat?
water
Chlorine dioxide gas is used as a sterilization method of…?
Enclosed areas or disinfection of water
Chlorine is used for?
Large scale disinfection of drinking water, sewage, swimming pools, restaurants, canneries, wounds, irrigate root canals
Iodine is a pungent blue-black element that forms a brown solution when dissolved in…?
water
Iodine is a intermediate level chemical agent that interferes with…?
Disulfide bonds of proteins
Iodine has three types of solutions which are?
Iodophor tincture iodine, aqueous iodine
Iodophor is less toxic, less staining, and is iodine with neutral protein polymer of what percent iodine?
2-10%
Common products of Iodophor are..?
Betadine and povidone
Tincture is an antiseptic made up of..?
2-3% iodine in 70% alcohol
Aqueous iodine is an antiseptic made up of?
2-3% iodine in water
Iodine solutions are used for?
Skin prep for surgery, burns, vaginal infections, surgical hand scrubbing and disinfecting equipment
The halogen fluorine is used in?
Toothpaste and drinking water
The halogen bromine is used in?
Hot tubs
Aldehydes have what type of functional group?
CHO
Two most commonly used aldehydes are?
Glutaraldehyde and formaldehyde
Formaldehyde is a sharp, irritating gas that dissolves readily to form a?
Aqueous solution called formalin
Formaldehyde creates a solution called formalin that is what percent of formaldehyde gas in water?
37%
Formaldehyde is extremely toxic on skin and mucous membranes, and also classified as a?
Carcinogen
Formaldehyde is used for?
Surgical instruments, biological specimens, embalming fluid, vaccine preparation
Glutaraldehyde is less toxic and irritating with a yellow acidic liquid and ..?
odor
Glutaraldehyde is a rapid and broad spectrum chemical that is a sterilant and kills spores in less than…?
3 hours
What aldehyde chemical is used in a special device known as a chemiclave?
Glutaraldehyde
Glutaraldehyde is used for?
Respiratory therapy and kidney dialysis equipment, endoscopes, alternative for vaccine preservative
Gaseous agents include…?
Ethylene oxide, propylene oxide, and chlorine oxide
Ethylene oxide is a colorless substance that is a gas at what temperature?
Room temperature
What gaseous agent chemical is highly explosive in air and is mixed with carbon dioxide when using ETO sterilizer?
Ethylene oxide
Which gaseous agent is accepted as a chemical sterilizing agent?
Ethylene oxide
Everyone outside is very toxic and rated as a?
Carcinogen
Ethylene oxide is used for?
Prepackage medical supplies that are plastics, pacemakers, artificial heart valves, disinfectant of food such as spices dried fruits and drugs
Heavy metals that are used in chemical control of microbes are?
Mercury, silver, gold, copper, arsenic, zinc
The most commonly used low level heavy metals are?
Mercury and silver
Mercury and silver are used to kill?
Vegetative cells in low concentrations
Mercury and silver do what to cells?
Inactivate proteins
Heavy metal germicide contain a metallic salt and are in the form of?
Equations solutions, tinctures, ointments or soaps
Mercury tinctures are .001-.2% in what solution?
Alcohol
Mercury tinctures are used for?
Skin antiseptics, preservative in cosmetics and ophthalmic solutions
Mercurochrome is also known as?
Monkey’s blood (1919- 1998)
Merthiolate/ thimerosal was wrongly associated with?
Autism
Silver nitrate is used to prevent eye infections in…?
Newborns
Silver sulfadiazine ointments are used for…?
Burn patients
Band-aids, surgical bandages can also contain what heavy metal?
sliver
Appliances are also made out of what heavy metal?
Silver
Catheters with silver is used to prevent…?
UTI’s
Copper/ Copper sulfate is a great algicide used for?
Swimming pools and fish tanks.
Zinc chloride is used in?
Mouthwashes
Zinc oxide is used in?
Calamine lotion, diaper ointments, baby powder, and dandruff shampoos.
Soaps are alkaline compounds made when combining sodium or phosphate salts and…
Long chain fatty acids
Soaps interact with oils and grease to create emulsions in water, and loosening and lifting away dirt and microbes on surfaces and…?
skin
Soaps are not antiseptics or disinfectants but help to mechanically carry away…?
Microrganisms
What agent is common in soaps?
Sodium lauryl sulfate
Detergents are both aniotic and…?
Cationic
Anionic detergents have a long hydrophobic chain that is connected to…?
a negatively charged anion
Anionic detergents are used in…?
Laundry soap
Cationic detergents have a long hydrophobic chain that is connected to…?
A positively charged cation
The most important detergents are what kind of salts?
Quaternary ammonium salts
Detergents enter into phospholipid bilayer and disrupt the…?
Cell membrane
Most common detergents are made out of?
Benzalkonium chloride
A chemical that destroys vegetative stages of bacteria is…?
Bactericide
A _________ can destroy bacterial endospores
sporicide
_____________ agents inhibit or prevent the growth of bacteria on tissues or on other objects in the environment
Bacteriostatic
A germicide or microbicide is a chemical that will kill…?
any pathogenic microorganisms
An antiseptic is a chemical applied to living tissues to…?
render them free of pathogens
Sanitization is forceful cleaning that removes contaminants and makes objects…?
hygienic and safe to use
Degermation is forceful cleaning of the body to remove
potential pathogens
2 Physical Methods of Control are…?
radiation and filtration
Dyes, acids, and alkalis can also inhibit or destroy microbes but are…?
limited in use