transes 3 and 4

perfect final exam

STERILIZATION

**the process by which all living cells, viable spores, viruses and viroid are either destroyed or removed from an object or habitat.** eliminate all forms of living, pathogenic or nonpathogenic cells

placing in an oven, high heat, and autoclaving

ex. of sterilization

CLEANING

the removal of visible soil from objects and surfaces. Normally accomplished manually or mechanically using water with detergents or enzymatic products.

DECONTAMINATION

the process of removing or neutralizing contaminants that have accumulated on personnel and equipment

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**most critical aspect of health** and safety, especially if the site is hazardous

DISINFECTION

describes a process that eliminates many or all pathogenic microorganisms, except bacterial spores on inanimate objects. **used on inanimate objects**

DISINFECTANTS

agents usually chemical used to carry out disinfection and are normally used only on inanimate objects.

SANITATION

the microbial population is reduced to levels that are considered safe by public health standards

ANTISEPSIS

prevention of infection or sepsis and is accomplished with antiseptics

ANTISEPTIC

chemical agents applied to living tissue to prevent infection by killing or inhibiting pathogen growth. They also reduce the total microbial population.

povidone iodine, hydrogen peroxide, and alcohol

common antiseptics

GERMICIDE

kills pathogens but not necessarily endospores

BACTERIOSTATIC AND FUNGIASTIC

they do not kill, but they prevent growth

erythromycin

target ribosomes and stop the production of protein so the organism will stop replicating

1. population
2. CONCENTRATION OR INTENSITY
3. DURATION OF EXPOSURE
4. TEMPERATURE AND pH
5. LOCAL ENVIRONMENT

CONDITIONS INFLUENCING THE EFFECTIVENESS OF ANTIMICROBIAL AGENTS

t

younger cells are more readily destroyed than mature cells.

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t or f?

At higher concentration of alcohol, it can precipitate the protein of the bacterial cell. Thus, the outer covering of the cell will protect the organism from alcohol.

why alcohol should have a lower concentration?

HYDRATED (WET METHODS)

methods of boiling, pasteurization, tyndallization, and autoclaving

coagulation of proteins

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Enzymes are all protein. For bacterial cells to divide, they need many enzymes to catalyze the reaction and produce energy. If the enzyme is subjected to heat, it coagulates and destroys the chemical property of protein and render it inactive.

MOA of HYDRATED (WET METHODS)

121°C, 15 pounds per square inch, 15-20 minutes

conditions for autoclaving

autoclave tapes

use to see the visible reaction through change of color or formation of stripes on the tapes that indicates that the requirement is met.

Probes/thermocouples

devices placed inside the autoclave that sends signals to a control room if the requirement for autoclaving is met.

Biological indicator

use of bacterial spores like Geobacillus stearothermophilus done by microbiologists.

DRY METHODS

preferred for single-use materials and stable materials like stainless steels.

MOA: oxidation of cells

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hot air oven, flaming, and incineration

MOA OF DRY METHODS AND IT’S EXAMPLE

LOW TEMPERATURE

will only halt or stop the growth of microorganisms but it does not kill them

Freezing and refrigeration

most convenient control technique

Deep freezing (liquid N2)

cryoscopic freezer for human cells or tissues

Ultralow freezer

can preserve up to - 17°C and -196°C

Lyophilization or freeze drying

preserve large volume of microorganisms into powdered form.

FILTRATION

physical separation of the organisms from a solution AND used to sterilize solutions which are heat- sensitive

depth filters

consists of fibrous or granular materials that have been bonded into a thick layer filled with twisting channels of smaller diameter; normally seen in pipes when filling drugs.

membrane filter

are porous membrane about 0.1mm thick, made of cellulose acetate, cellulose nitrate, polycarbonate, and polyvinylidene fluoride, or some other synthetic material

FILTRATION OF AIR

method of sterilization where a microorganism present in the air is filtered through HEPA?

Laminar flow biological safety cabinets

equipment that employs hepa filter in the laboratory

High-efficiency particulate air (HEPA) filter

remove almost all microorganism larger than about 0.3 micrometer in diameter.

positive inside

air will go out so that air particles outside will not go in

MOA: cause lethal form of mutation

MOA OF RADIATION

negative inside

air will go in so that air particles inside will not go outside

ionizing radiation

is an excellent sterilizing method because it can penetrate deep into objects.

RADIATION

destroy bacterial endospores and vegetative cells, both prokaryotic and eukaryotic causing damage to the cell and to the process of mutation.

Gamma radiation from cobalt 60

is used in the cold sterilization of antibiotics, hormones, sutures, and plastic disposable supplies

Antibiotics cannot be subjected to high heat, otherwise, it will destroy the active ingredient and will render the antibiotic inactive.

why antibiotics are sterilized through Gamma radiation from cobalt 60

Food irradiation

can eliminate pathogens such as E. coli, Staph aureus, and Campylobacter jejuni

• must be **effective against a wide variety** of infectious agents

• must be **toxic to infectious agents**, but **not to people** or corrosive for common materials

• should be stable upon storage, odorless or with pleasant odor, soluble in water and lipids for penetration into microorganisms

• low surface tension so it can enter cracks in surfaces

• relatively inexpensive

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CHARACTERISTICS OF CHEMICAL AGENTS

surface tension

ability of water or liquid to resist an outside force

Used as the standard for determining the disinfectant property of substances

**First widely used antiseptic and disinfectant**

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Used as the standard for determining the disinfectant property of substances

Used as the standard for determining the disinfectant property of substances

Phenol coefficient

term when a disinfectant’s efficacy is compared to phenol.

f

Phenol is 1 and lower than 1 means that a disinfectant effectivity is same with phenol

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t or f

Cresol, Xylenols , Orthophenol

examples of phenols

MOA: primarily affecting bacterial cell membranes

* disrupt the cell membrane so that the organism will lyse

moa of biguanides

tt

biguanides are especially effective against gram (+) and gram (-) bacteria.

\
t or f?

chlorhexidine

The best known biguanide which is frequently used for microbial control on skin and mucous membranes. Common in mouthwash

ALCOHOLS

Most widely used disinfectants and antiseptics.

tt

alcohol is Bactericidal and fungicidal but not sporicidal

t or f

PROTEIN DENATURANT

MOA OF ALCOHOL

ethanol and isopropyl

types of alcohol

MOA: oxidizing agent

moa of HALOGENS

fluorine, chlorine, and iodine

examples of halogens

Iodine

tincture (has alcohol) of Iodine, povidone iodine

Chlorine

a usual disinfectant for water supplies and swimming pools

MOA: binding to -SH groups of bacterial enzymes resulting to denaturation

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* Enzymes contain monomer of amino acids. Most of the active sites contain sulfur. sulfur when bind with heavy metal will render the enzymes inactive.

moa of HEAVY METALS

Oligodynamic property

some metal ions kill or inhibit the growth of microorganisms. This effect can be observed at extremely low doses.

silver coin

prevents growth of microorganism (in heavy metals)

1% Silver nitrate

often added to the eyes of infants to prevent ophthalmic gonorrhea.

Silver Sulfadiazine

used on burns (ex. in heavy metals)

Zinc undecylenate

used as antifungal (ex. in heavy metals)

Copper Sulfate

an effective algaecide in lakes and swimming pools

MOA: surface-active agents. Precipitate or denature proteins

MOA OF QUATERNARY AMMONIUM COMPOUND (QUATS)

benzalkonium chloride, benzethonium chloride, methylbenzethonium chloride, and cetylpyridinium chloride.

EXAMPLES OF CATIONIC SURFACTANTS

MOA: can decrease surface tension among molecules of a liquid.

MOA OF SURFACE-ACTIVE OR SURFACTANTS

emulsification

process when soap breaks the oily film into tiny droplets

SLS (sodium lauryl sulfate), soaps

example of SURFACE-ACTIVE OR SURFACTANTS

• MOA: acts through alkylation of amino-, carboxyl- or hydroxyl group, and probably damages nucleic acids.

* either adding or removing of alkyl group

moa of ALDEHYDES

o formaldehyde (10%) – high level disinfection

o glutaraldehyde

examples of aldehydes

f.u emz F

phenols are sporicidal and can be used as chemical sterilant

\
t or f?

Ethylene oxide (EtO)

is used to sterilize many heat-sensitive items like disposable plastic petri dishes, syringes, heart lung machine components, sutures and catheters.

carbon dioxide or dichlorodifluoromethane.

ethylene oxide is mixed with _ *or* _ since it is explosive and supplied in 10 - 20% amount only

Gentian violet

common treatment for thrush and some other skin, mouth, and vaginal infections caused by fungi.

MOA: alkylation

MOA OF ETHYLENE GAS

Prontosil

the first synthetic drug used in the treatment of general bacterial infections in humans.

Basic Fuchsin

ingredient of carbol-fuchsin solution (Castellani’s paint) for treatment of ringworm and athlete’s foot

Methylene blue

dye that is also used as a medication for conditions like **UTI** and antidote for **cyanide poisoning**. It is also used an antifungal and antiseptic agents for fishes.

Symbiosis

happens when different organisms live and interact together forming an interdependent relationship.

MUTUALISM

both species benefit from the interaction.

COMMENSALISM

one organism benefits while the other organism is neither harmed nor benefitted.

Candida

is commonly the cause of vaginal candidiasis.

Malassezia

cause dandruffs and an-an.

Candida albicans

When taking corticosteroids, the immune system goes down that leads to _ (Ex in commensalism)

ef-ef horray

can normal flora be considered as an opportunistic pathogen when they go to a site where they should not be?

t or f?

PARASITISM

one specie benefits while the other suffers or is harmed

Giardia lamblia

cause of giardiasis

o constant source of nourishment and moisture

o relatively stable pH and temperature for microbial growth

o the extensive surface area available

Humans are favorable host for microbes because of:

Microbiota

complex ecosystem consisting of bacteria, protozoa, viruses, and fungi that varies in number even in body parts of the same individual

Normal microbiota

refers to the microorganisms that reside on the layers of the skin, oral mucosa, saliva, conjunctiva, and in the GIT of human being.

indigenous microbiota or normal flora

Normal microbiota is also known as

o nature of the local environment (pH, temperature, redox potential, and oxygen, water, and nutrient levels)

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o peristalsis, saliva, lysozyme secretion, and secretion of immunoglobulins

* decrease the growth of normal flora in the body

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Factor that determines the composition of normal flora

RESIDENT MICROBIOTA

are life-long members of the body’s normal microbial community, but are not found everywhere

axenic area

sterile areas of the body like cerebrospinal fluid, lungs, and brain

TRANSIENT MICROBIOTA

are microorganisms that are just passing through. **may attempt to colonize the same areas of the body like resident microbiota but transients are unable to remain in the body for extended periods of time due to difficulty competing with established resident microbes.**