Name the 3 types of

Microbial Control Methods

Physical Agents

Chemical Agents

Mechanical Removal Agents

What applications are involved in the use of Physical Agents?

Heat

or

Radiation

What applications are involved in using Chemical Agents?

Gases

+

Liquids

What application is involved in using Mechanical Agents?

Filtration

Who is responsible for choosing appropriate microbial control methods?

Microbial Control

Method Officer

True or False

Microbial control methods eradicate microbes.

False: they reduce the number of microbes, and

may eradicate, but they

don't always.

True or False

It's harder to kill spores than to kill vegetative forms.

True

To kill endospores

apply moist heat at

120° or 100ºC?

Endospores killed at 120ºC

with moist heat.

Heat is a physical control method.

To kill vegetative forms

apply moist heat at

80° or 100ºC?

Vegetative forms are killed at 80ºC using moist heat.

Heat is a physical control method.

To kill endospores

apply 4,000 or 5,000

grays of radiation?

Endospores are killed

using 4,000 grays of radiation.

To kill vegetative forms

apply 1,000 or 1,500

grays of radiation?

Vegetative forms are killed with 1,000 grays of radiation.

Radiation is a physical killing agent.

To kill endospores

apply 1,000 mg/l or

1,200 mg/l of sterilizing gas?

What IS the gas used?

Endospores are killed by

 applying 1,200 mg/l of sterilizing gas (ethylene oxide). (remember ethyl alcohol??)

To kill vegetative forms

 apply 900 mg/l or

700 mg/l of sterilizing gas?

What IS the gas used?

Vegetative forms are killed by

 applying 700 mg/l of sterilizing gas (ethylene oxide). (remember ethyl alcohol??)

Endospores are killed after 3 days or 3 hours of exposure to sporicidal liquid?

>>Name the liquid.

Endospores are killed after 3 hours of exposure to a sporicidal liquid:

2% glutaraldehyde.

10 minutes

(Sporicidal liquids are chemical agents.)

Killing endospores and vegetative cells is an art.

True or False?

False - killing endospores and vegetative forms is a SCIENCE.

Cadenas statement about use of control agents

and bacterial resistance:

Higher resistance by endospores compared to vegetative forms is an argument for needing more Microbial Control Method Officers.

Define

STERILIZATION

Book: a process that destroys or removes all viable microorganisms, including viruses.

Cadenas: one should ask, "If not destroyed, where have the M/Os been moved, and where are they now?"

Define

STERILE

Book: any material that has been subjected to the process of destruction or removal of all viable microorganisms, including viruses.

Cadenas: THIS IS STRAIGHTFORWARD

Define

BACTERICIDE

Book: a chemical that destroys bacteria except for those in the endospore stage. It may or may not be effective on other microbial groups.

Cadenas: no further comment

Chopping up a capsid to destroy a virus is using what method of microbial control?

STERILIZATION DESTROYS OR REMOVES ALL VIABLE M/Os - this includes viruses. 

THIS WAS MENTIONED DURING SECTION ON DEFINITIONS. Chopping up viral capsids is a way to destroy viruses.

Define

FUNGICIDE

Book: a chemical that CAN kill fungal spores, hyphae and yeasts.

Cadenas: THIS IS NOT LIMITED TO FUNGI, PER THE DEFINITION. USE OF THE WORD CAN INDICATES THAT IT'S NOT ALWAYS EFFECTIVE.

Define

VIRUCIDE

Book: any chemical known to inactivate viruses, especially on living tissue.

Cadenas: THE VIRUSES ARE NOT KILLED BECAUSE VIRUSES ARE NOT ALIVE.

Define

BACTERIOSTATIC

Book: an agent which prevents the growth of bacteria on tissues or on objects in the environment.

Cadenas: STASIS = STOPPING/CEASING OF MOTION/TO STAND STILL. **this is a BACKUP MECHANISM used because a bactericide may not have killed all the bacteria. This would be Step 2.

Define

DISINFECTION

Book: the use of a physical process or a chemical agent (a disinfectant) to destroy vegetative pathogens but not bacterial endospores. (...usually only on inanimate objects)

Cadenas: WOULD NEED TO FOLLOW UP W/ANOTHER METHOD TO TAKE CARE OF SPORES LEFT BEHIND.

What is a

VEGETATIVE PATHOGEN?

Cadenas note:

veg. pathogen is a fully-grown disease-causing pathogen.

Define

SEPSIS

Book: the growth of microorganisms in the blood and other tissues.

Cadenas: IMPORTANT TO REMEMBER THAT SEPSIS IS NOT LIMITED TO BLOOD. One should ask,"How far has sepsis progressed? New/lingering infection? Any other tissues involved?"

Define

ASEPSIS

Book: any practice that prevents the entry of infectious agents into sterile tissues and thus prevents infection.

Cadenas: THIS IS PREVENTATIVE, WHICH IS A MAJOR FOCUS IN HEALTHCARE.

Define

"ZANITIZATION"

(just a "Cadenas-ism")

Sanitization: any cleansing technique that removes debris, microorganisms, and toxins, and in this way reduces potential for infection and spoilage.

Cadenas: SPORES ARE INCLUDED IN THIS! DEBRIS = food for M/Os.

3 Cadenas suggestions re: qualities of chemical agents used by healthcare workers...

1. Killing spores ≠ always killing bacteria.
2. You should monitor drugs being removed from market, has legal and health implications.
   
3. Know drugs you are administering, you'll need to monitor therapeutic levels.

CHLORINE

Microbes targeted:   SLOW sporicidal

Leval of Activity:      Intermediate

Toxicity:                  ↑ toxic gas (vapors), skin irritant

             Inactivated by organics, unstable in sunlight.

Cadenas: NOT bacteriostatic or bactericidal AT ALL. Can introduce problems due to cracks in skin. Strong enough to kill spores ≠ strong enough to kill bacteria.

IODINE

Microbes targeted:   SLOW sporicidal

Leval of Activity:      Intermediate

Toxicity:                  Tissue irritant, Toxic to ingest

Cadenas: NOT TO BE LEFT IN ROOM WITH PATIENTS OF ANY AGE. Also, many believe that if it hurts, it must be clean!

ALCOHOL

Microbes targeted:   Most bacteria, viruses, fungi

Leval of Activity:      Intermediate

Toxicity:                  Toxic to ingest, mild irritant, dries skin

                              also Flammable, fast-acting

Cadenas: no comment

SOAPS

Microbes targeted:   Certain very sensitive species

Leval of Activity:      VERY LOW

Toxicity:                  Nontoxic, few if any toxic effects

Cadenas: USED FOR REMOVING SOIL, OIL, DEBRIS. More effective soaps lift both + and - charged items from surface or skin.

MERCURIALS

Microbes targeted:   WEAKLY microbistatic

Leval of Activity:      LOW

Toxicity:                  HIGHLY Toxic to ingest, inhale, absorb

Cadenas: USED OUTSIDE OF THE U.S. THESE DAYS. This does not kill ANYTHING, and barely even slows down the M/Os.

GLUTARALDEHYDE

Microbes targeted:   Sporicidal

Leval of Activity:      HIGH

Toxicity:                  Can irritate skin, Toxic if absorbed

Cadenas: EMPHASIZED HIGH LEVEL OF TOXICITY IF ABSORBED.

TRUE OR FALSE

Soaps kill microorganisms.

False:

soaps only lift surface debris, etc. from skin.

Only added antimicrobial chemicals would kill some M/Os.

SOAPS:

cationic soaps are

preferable why?

Cationic soaps/detergents have:

molecules with a + charged end

(binds with - charged bacterial surface proteins)

and

an uncharged hydrocarbon chain which

helps lyse M/O cell membrane.

(p. 343)

>>>we have to know ALL OF TABLE 12.1 ON P. 352

characteristics of the

 IDEAL ANTIMICROBIAL DRUG

1. Selectively toxic to _______ but nontoxic to _____.
2. Microbicidal rather than microbi________.
3. Relativley soluble; functions even when highly diluted in ________ fluids.
   

>>>we have to know ALL OF TABLE 12.1 ON P. 352

characteristics of the

 IDEAL ANTIMICROBIAL DRUG

(continued)

4. Remains potent long enough to act and is not _________ or _______ prematurely.

5. Doesn't lead to the development of _______. (Hint: Cadenas also stated that we don't want drug to allow Transformation.)

>>>we have to know ALL OF TABLE 12.1 ON P. 352

characteristics of the

 IDEAL ANTIMICROBIAL DRUG

(continued)

6. Complements or assists the activities of the host's ___.

7. Remains active in tissues and _____.

8. Readily delivered to the site of _____.

>>>we have to know ALL OF TABLE 12.1 ON P. 352

characteristics of the

 IDEAL ANTIMICROBIAL DRUG

(continued)

9. Reasonably priced.

10. Does not disrupt the host's health by causing ____ or predisposing the host to other ____.

Name the 5 mechanisms for Antimicrobials

(the targets for these drugs)

1) inhibition of cell wall synthesis

2) breakdown of the cell membrane structure or function

3) inhibition of structures and functions of DNA and RNA

4) inhibition of protein synthesis

5) blocks on key metabolic pathways (via enzymes)

What is the

Therapeutic Index?

The measure (an indicator)

of a drug's toxicity

Therapeutic Index

 Is a TI of 10 better

than a TI of 1.1?

a TI of 10 is much better. A lower ratio such as 1.1 indicates that the

MINIMUM effective (therapeutic dose)

is very close to the toxic dose

Define

CARRIER

Book: An individual who inconspicuously

shelters a pathogen and spreads

it to others without any notice.

Define

VECTOR

Book: a live animal that transmits an infectious agent from one host to another

Define

ZOONOSIS

Book: an infection indigenous to animals but naturally transmissible to humans.

Define

COMMUNICABLE

Book: describes disease when an infected host can transmit the infectious agent to another host and establish infection in that host

Define

CONTAGIOUS

Book: when an infectious agent is highly communicable, especially through direct contact

Define

NOSOCOMIAL INFECTION

Book: infectious diseases that are acquired or develop during a hospital stay