Microbiology Chapter 5

Front 1

Who thought of the first aseptic techniques during WW2?

Back 1

Joseph Lister

Front 2

Sterilization

Back 2

removal of ALL microorganisms (living and non living except prions)

Front 3

Sterile

Back 3

describes an item free of microbes including endospores and viruses

Front 4

Disinfection

Back 4

elimination of most or all pathogens

(some viable microbes may remain)

Front 5

Disinfectants

Back 5

biocides, germicides, bactericides

Front 6

Antiseptics

Back 6

disinfectants used on living tissues

Front 7

Pasteurization

Back 7

Brief heating to reduce number of spoilage organisms, destroys pathogens

Front 8

Decontamination

Back 8

reduce pathogens to levels considered safe to handle

Front 9

Sanitize

Back 9

substantially reduce microbial population that meets accepted health standards. (non specific levels)

Front 10

Preservation

Back 10

process of delaying spoilage of food and other perishable goods

Front 11

Bacteriostatic

Back 11

a growth-inhibiting preservatives

Front 12

How come soap does not affect the beneficial skin mictobiota?

Back 12

They reside deeper on underlying layers of skin and in hair follicles.

Front 13

How long to wash hands for?

Back 13

at least 20 seconds

Front 14

What does the FDA regulate the risk of?

Back 14

Toxicity

Front 15

Describe the standards of drinking water.

Back 15

free of pathogens, not sterile

Front 16

What chemical is usually used to clean drinking water?

Back 16

Chlorine

Front 17

What is the downside to chlorine?

Back 17

Forms DBPs, disinfection by-products, which are linked to long-term health risks

Front 18

What is the downside of only chemical water treatment?

Back 18

Some organisms resist chemical disinfectants

Front 19

What are the 4 factors considered when selecting and antimicrobial procedure?

Back 19

1. type and # of microbes

2. Environmental conditions

3. risk of infection

4. composition of infected items

Front 20

Why are endospores highly resistant?

Back 20

Only extreme heat or chemicals can completely destroy them

Front 21

Why are protozoan and oocysts highly resistant?

Back 21

resistant to disinfectants (causes diarrheal disease)

Front 22

Why are Mycobaterium spp. highly resistant?

Back 22

Their wall are made of mycolic acid which cause a waxy cell wall resistant to many chemical treatments

Front 23

Why are Pseudomonas spp. highly resistant?

Back 23

resistant to and can grow in disinfectants

Front 24

Why are naked viruses highly resistant?

Back 24

they lack a lipid envelope and are more resistant to disinfectants (alcohols dont work)

Front 25

Even supplies that have been autoclaved have........ on it.

Back 25

prions

Front 26

Decimal reduction time

Back 26

The time it takes to to kill of x amount of microbes (exponential decay)

Front 27

What is one way to speed up decimal reduction time on the body?

Back 27

Wash your hands! and body.

Front 28

What environmental conditions interfere with cleaning the body of germs?

Back 28

dirt, grease, body fluids, heat penetration

Front 29

What can influence the effectiveness of a cleaning procedure?

Back 29

pH and temperature

Front 30

What are the pros to heat treating? (Autoclaving)

Back 30

reliable, safe, relatively fast, inexpensive, nontoxic, can be set to sterilize or disinfect, and can use moist or dry heat

Front 31

What does heat do to "kill" a microbe?

Back 31

irreversibly denatures it's proteins.

Front 32

Describe how to check an autoclave if it is running properly.

Back 32

You insert a crushable capsule which contains bacteria. Run through the autoclave. Then crush the capsule. If bacteria grows then it does not work properly.

Front 33

True or False: The canning process has procedure which include eliminating endospores?

Back 33

False: to REDUCE the number of endospores to about 1

Front 34

What is a reason why you would use dry heat?

Back 34

Powders, and other material which would be affected chemically by the moisture

Front 35

What is a con of dry heat?

Back 35

1. it takes longer

2. higher temperature

3. Things get could get so oxidized that they become incinerated

Front 36

What are some pros of Gamma and X ray radiation a sterilizer?

Back 36

can be used for heat sensitive materials

can be used after packaged because of penetration abilities

is FDA approved

Front 37

What can Ionizing radiation do to microbes?

Back 37

1. destroys DNA

2. damages cytoplasmic membranes

3. reacts with O2 to produce reactive oxygen species

Front 38

What is the downside to Ultraviolet radiation?

Back 38

can now penetrate through much. Only kills where it shines directly.

Front 39

How do microwaves work?

Back 39

They don't actually kill the cell specially, the heat does. It also heats the water inside of the (food) and acts like a moisture heat autoclave

Front 40

Why is high pressure preferred over radiation?

Back 40

1. It doesnt scare the general public

2. Food keeps it taste and color

Front 41

Sterilants

Back 41

destroy all microorganisms. used for critical instruments

Front 42

High level disinfectants

Back 42

destroy viruses and vegetative cells (NOT endospores) used in semi-critical instruments. (touches mucus membranes)

Front 43

Intermediate-level disinfectants

Back 43

destroy vegetative bacteria, mycobacteria, fungi, and most viruses. used on non-critical instruments

Front 44

Low-level disinfectants

Back 44

Destroy fungi, vegetative bacteria except mycobacteria, and enveloped viruses (NOT naked viruses) Used on floors, furniture, and walls.

Front 45

What are some on the considerations in choosing a germicide?

Back 45

Toxicity, activity, compatibility, residues, cost, storage, environmental risk.

Front 46

What is the preferred dilution of alcohol and why?

Back 46

60-80%. Less than 60 is too weak. You need at least 20% water because it helps dissolve proteins which alcohol can then get into contact with and denature proteins.

Front 47

What is the preferred % of alcohol concentration in hand-sanitizers?

Back 47

60% or more

Front 48

Why do we not use aldehydes as sterilants alot?

Back 48

Inactivates proteins and nucleic acids (of human cells too!)

Front 49

What is the popular gaseous sterilant?

Back 49

Ethylene oxide

Front 50

What specific chemicals on the periodic table are good germicides?

Back 50

Halogens

Front 51

What are the the metal compound made of?

Back 51

metal combined with sulfhydryl groups of enzymes and proteins.

Front 52

What is the downside of using metal compounds?

Back 52

1. Expensive

2. Not environmentally friendly

Front 53

What is an alternative of chlorine to disinfect drinking water?

Back 53

Ozone

Front 54

What are the downsides of ozone?

Back 54

1. unstable

2. decomposes quickly so must be made on site

Front 55

Peroxygens

Back 55

powerful oxidizers used as sterilants, readily biodegradeable, no residues, less toxic than ethylene oxide, can be used on surfaces

Front 56

Phenolic compounds

Back 56

Denature proteins and destroys cytoplasmic membranes. destroy most vegetative bacteria but not reliable on viruses.

Front 57

Quats, Quaternary Ammonium compounds

Back 57

positively charged detergents, nontoxic, and used on the surfaces of food prep

Front 58

How do Quads work?

Back 58

Charged hydrophilic and uncharged hydrophobic regions

1. reduce surface tension of liquids

2. aids in removal of dirt, organic matter, and microorganisms

Front 59

How do Quads affect cells?

Back 59

1. react with membranes

2. destroy vegetative bacteria and enveloped cells

3. Pseudomonas can grow in Quads

Front 60

Describe a dilution test for disinfectants

Back 60

A rings has bacteria that is dried. The ring is then placed in disinfectant for 10 minutes at 20 C. Ring placed in media to see if the bacteria can survive the disinfectant or not.

Front 61

Describe a disk diffusion test for disinfectants.

Back 61

A disinfectant spot is marked in a petrie dish that is fully streaked. If it doesn't grow there than it works.

Front 62

As a preservation a for food, weak organic acids are used for what? (Benzoic. sorbic, propionic)

Back 62

Inhibit metabolism and alter cell membrane function.

Control molds and bacteria in foods and cosmetics

Front 63

What are nitrates used for?

Back 63

inhibit endospore germination and vegetative cell growth within meat

Front 64

What does low-temperature mean for bacteria?

Back 64

It slows the growth and sometimes the ice crystal formation can kill the cells

Front 65

What is the purpose of adding salt as a preservative ?

Back 65

To remove the water from the system and causes cell to shrink!