Chapter 5

Question 1

A) What is the process of sterilization?

Answer 1

heat, filtration, chemicals, irradiation ????

Question 2

1) What does it mean for something to be sterile?

Answer 2

all the bacteria are all removed/ killed in a certain product… free of microbes.(doesn’t include prions)

Question 3

B) What is the process of disinfection?

Answer 3

eliminaiton of most or all pathogens are removed from a product.

Question 4

1) What can disinfectants do?

Answer 4

remove/ kill microorganisms

Question 5

2) What are germicides? What does it mean to be bactericidal?

Answer 5

Are a disinfectant that kill bacteria. that is what bactericidal means… they kill bacteria

Question 6

3) What are antiseptics?

Answer 6

antimicrobial chemicals that are not too toxic and can be used on the skin.

Question 7

C) What is pasteurization?

Answer 7

when you heat a liquid high temp a short time (typically). used to destroy heat sensitive organisms

Question 8

D) What is the process of decontamination?

Answer 8

process to reduce micro o. to a level that is considered safe to handle.

Question 9

E) What is the process of sanitization?

Answer 9

substantial reduction of a pop. to meet accepted health standards

Question 10

F) What is the process of preservation?

Answer 10

delaying spoilage of food, by chemicals, storage of food etc.

Question 11

1) What does it mean to be bacteriostatic?

Answer 11

inhibit growth of bacteria, but do not kill them

Question 12

G) Which situations warrant microbial control? [Figure 5.1]

Answer 12

in homes, hospitals, food and water plants

Question 13

H) What are healthcare associated infections?

Answer 13

infections linked to hospitals/ clinics

Question 14

I) What is the aseptic technique? How does it relate to BSL levels?

Answer 14

methods used to keep from contaminating samples you are working with. Bio safety levels wich rate how dangerous a pathogen is. and helps you know procedures to keep you safe.

Question 15

K) What are disinfection by-products and what are the health risks?

Answer 15

when chemical reacts with naturally occuring chemicals in water and have been linked to long term health risks

Question 16

A) Which are the highly resistant microbes?

Answer 16

Bacterial endospores, protazoan cyst/ oocytes, mycobacterium, pseudomonas species, naked virus

Question 17

B) What is the D value and what is it used for? [Figure 5.2]

Answer 17

decimal reduction time: time required to kill 90% of a microbial pop. under specific conditions

Question 18

C) What environmental conditions can affect death rates in microbe populations?

Answer 18

temp. and ph

Question 19

D) Which instruments pose greater threat of transmission of microbes?

Answer 19

used in invasive proceedures aka needles ect.

Question 20

E) How does the type of material dictate the sterilization and disinfection procedures?

Answer 20

some can handle heat, others are chem sensitive.

Question 21

A) What physical methods are used to destroy microorganisms and viruses? [Table 5.1]

Answer 21

heat, dry heat, filtration, radiation, high pressure

Question 22

1) What does high-temperature-short-time and ultra-high-temperature processing mean?

Answer 22

these are refering to pastuerization

Question 23

2) What are autoclaves? What are they used for? [Figure 5.3 and 5.4]

Answer 23

heat and pressure to create steam to sterilze

Question 24

3) What does it mean to be commercially sterile?

Answer 24

endospores and thermophils may have survived

Question 25

A) What are membrane filters and what do they do? [Figure 5.5]

Answer 25

microscopic pores that let water through, but not the microo. (typically .2 micrometers.

Question 26

B) What are depth filters?

Answer 26

trap material withing thick porous filtration material.

Question 27

C) What are HEPA filters?

Answer 27

air filter remove .3 micrometers or bigger

Question 28

D) What is electromagnetic radiation? [Figure 5.6]

Answer 28

short waves high E. x rays, gammarays, uv rays ect.

Question 29

1) What is ionizing radiation and how is it used against microbes?

Answer 29

destroys dna and cytoplasmic membranes

Question 30

2) What is ultraviolet radiation and how is it used against microbes?

Answer 30

uv light 220 to 300nm damages dna, so affects more so replicating org.

Question 31

3) What are microwaves and can they be used against microbes?

Answer 31

the waves themselves don’t do anything, but the heat can.

Question 32

E) How can high pressure be used against microbes?

Answer 32

high pressure used so you don’t use heat.the pressure is believed to denature protiens (13000psi)

Question 33

A) How are germicides grouped according to their potency? (What are the groups?)
]

Answer 33

Sterilants: kills all micro o’s inclueding endospores “sporillants” Takes 6-10 hours to kill endospores
High level disinfectants: destroys viruses and vegatative micro o’s
Intermediate level: destroy all vegitateive bacteria and mycobacteria, fungi, and most viruses
Low level: fungi and vegit. bacteria ( not mycobacteria)

Question 34

B) What points should be considered when choosing a germicide?

Answer 34

Toxicity, reaction with org molec., compatability with ,material, residue, cost and availability storage stability, environmental risk

Question 35

C) What are the characteristics and uses of the germicidal chemical groups? [Table 5.2

Answer 35

Alchohols: aqeuos solutions as antiseptics and disinfect instraments
Aldehydes: sterilize med equip. used in some vaccines and preserve bio. specimens
Biguanides:antiseptic in soaps and lotions. Impregnated in catheters and mesh
Ethylene oxide gas: sterilize med equip.
Metals:used in topical dresssings, prevent eye infection in new borns
Ozone: disinfect water
Peroxygens:sterilize containers ie milk jugs etc and med supplies
Phenolic compounds:in toothpaste lotions and deodorant, but only in limited amouns cause it can cause neurological damage
Quanternary ammonium compounds: preserve non food substnces and disinfect

Question 36

A) What are some of the chemical preservatives that can be used on food items?

Answer 36

Benzoic, sorbic and prepionic acid , nitrate in meats

Question 37

B) How do low temperatures, salting and drying preserve food?

Answer 37

Low temp: inhibits growth of pathogens

Water and salt: inhibit growth due to lack of water and high salt concentratioin leads o plasmolysis

Question 38

1) Why is sugar or salt used when canning? [Figure 5.8]

Answer 38

Lead to dehydrating cells

Question 39

2) What is lyophilization?

Answer 39

Freeze drying!