x Micro, 4, Control of Microorganisms

Question 1

Bactericide

Answer 1

KILL all bacteria, nothing else

Germicide - kill germs
Virucides - kill virus

Question 2

Bacteriostatic

Answer 2

• inhibit bacteria growth
• stops reproduction of bac.
• controls growth
• may not kill

Question 3

Sterilization

Answer 3

• Eliminate ALL microorganisms

- KILL bac, vir, fung, spores

Question 4

Methods of Sterilization

Answer 4

Heat, Chem, Radiation, Pressure, Filtration

Question 5

Asepsis

Answer 5

free of all forms of microorganisms

Question 6

Disinfection

Answer 6

destroying microorganisms on non living objects

Question 7

Antisepsis

Answer 7

antimicrobial substance applied to living tissue/skin to reduce possibility of infection, sepsis or putrefaction.

Question 8

Sanitation

Answer 8

promoting hygiene to prevent human contact with waster.

Question 9

Antibiosis

Answer 9

biological interaction btwn 2 or more orgs that is detrimental to at least one

Question 10

Drying

Answer 10

remove water cells, shrivel, die

foods can be dried by mixing them with salt or sugar.

Question 11

Lyophilization

Answer 11

liquids are quick frozen, then subject to evacuation, which dries material (salted meats, sugared fruit)

Question 12

TDP (Thermal Death Point)

Answer 12

lowest temp when microorgs killed in 10 min.

Question 13

TDT (Thermal Death Time)

Answer 13

minimum amount of time to kill all microorgs at given temp.

Question 14

DRT (Decimal Reduction Time)

Answer 14

amount of time to destroy 90% of microbial population.

Question 15

Types of HEAT control methods

Answer 15

• DRY HEAT: kill by oxidizing proteins
• DENATURATION: 3D protein to 2D, breakdown
• MOIST HEAT: kill in boiling water, most killed in 2-3 min.
• AUTOCLAVE: high press, steam is superheated for sterilization

Question 16

Types of PHYS control methods

Answer 16

• Pasteurization
• Radiation
• Filtration

Question 17

Pasteurization

Answer 17

• lower bacterial count in milk, dairy
• does NOT sterilize
• kills orgs that cause listeriosis, tuberculosis, burcellosis, typhoid fever, diptheria
• DENATURES PROTEIN

Question 18

Radiation

Answer 18

• damages DNA
• Ionizing radiation (xrays, gamma, electron beams)
• nonionizing radiation (UV)
• microwaves kill by heat, not very microbial

Question 19

Filtration

Answer 19

• liquid passed thru screen filter our microorgs
• vacuum can be used to pull fluids through filter
• Osmotic Press leads to plasmolysis, cause loss of water from cell, contracting plasma membrane

Question 20

CHEM methods of control

Answer 20

• not intended to sterilize
• reduce microorgs, remove pathogens
• best chem kills in shortest time w/out damaging material

Question 21

Action of Microbial Agents

Answer 21

• alteration of membrane permeability (cause bigger ‘holes’ in membrane and weaken cell wall)
• damage to proteins (can’t survive without them)
• Damage to nucleic acid (no replication, mutations)

Question 22

Halogens

Answer 22

• Oxidizing agents
• Iodine (betadine)
• Chlorine

Question 23

Alchohols

Answer 23

• denature protein, dissolve lipid
• use against fungi and some enveloped viruses
• NO EFFECT on bac SPORES
• 70% ETOH most effective.

Question 24

Phenol

Answer 24

• discovered by Joseph LISTER (Listerene) for disenfection
• damages cell membrane and inactivates enzymes of microorgs while denaturing protein
• Lysol (cresols)
• Hexachlorophene (bisphenols)

Question 25

Heavy Metals

Answer 25

- denature protein - Silver (Ag) - Silver nitrate in eye of newborns again Neisseria gonorrhea - Copper (Cu), shock swimming pools, fish tanks, reservoirs to reduce algae growth - Zinc (Zn): Zinc Chloride in mouthwash, Zinc oxide antifungal in pants and for diaper rash

Question 26

Aldehydes & Peroxides

Answer 26

Aldehydes: formaldehyde and glutaraldehyde, inactivate proteins by crosslinking functional groups of proteins. Formalin use for embalming - Ethylene Oxide: gas to denature proteins - Peroxide: hydrogen and benzoys peroxide

Question 27

Soap / Detergents

Answer 27

- decrease surfac tension btwn microorg and surface - Soaps: emulsify oily film on body, carry away oil, debris in de-germing action - Cationic Detergents: Quaternary ammonium compounds. Dissolve cell membranes of microorgs

Question 28

Phenol coefficient test (PC)

Answer 28

used to evaluate effectiveness or antiseptic or disinfectant PC > 1 = chemi is more effective than phenol PC < 1 = chem less effective than phenol

Question 29

Antiviral

Answer 29

- inhibit viral growth, NOT KILL - decrease viral load - specific antiviral drug used for specific virus.

Question 30

Antifungal

Answer 30

- meds used to treat fungal infec. | - work by identifying differences between human and fungal cells to kill organism without harming host.

Question 31

Antiparasitic

Answer 31

treat parasite disease i.e. head lice, scabies, trich, vaginalis, nematodes, cestodes, trematodes, infections protozoa, amoebas

Question 32

Who discovered PCN (Penicillin)?

Answer 32

Alexander Fleming, 1928 -bactericidal - KILL

Question 33

Types of Abx

Answer 33

- Broad spectrum: wide range of bac (gm neg and pos) - Narrow spectrum: specific type of bac - Superinfection: secondary infection after primary infection is killed

Question 34

Alcohols have NO effect on

Answer 34

- Bacterial Spores | - non enveloped viruses

Question 35

The most effective wavelength for microorganisms

Answer 35

260nm

Question 36

Shorter Wavelength =

Answer 36

higher energy

Question 37

How do Abx work?

Answer 37

- inhibit cell wall synthesis - Inhibit protein synthesis - injure plasma membrane

Question 38

Types of Abx

Answer 38

Bacteriostatic: slow growth of bac. by: - inhibit DNA replication - interfere with metabolism - inhibit protein synthesis Bactericidal: kill bacteria by -prevents cell wall synthesis

Question 39

Do Viruses have cell walls?

Answer 39

NO, that's why abx that affect cell wall can not kill viruses.

Question 40

Vancomycin

Answer 40

inhibit cell wall synthesis

Question 41

Acyclovir

Answer 41

inhibit DNA or RNA synthesis

Question 42

Tetracycline

Answer 42

inhibit protein synthesis

Question 43

Sulfonamides

Answer 43

inhibit synthesis of metabolites