Means of sterilization

Question 1

steam sterilization (autoclaving)

Answer 1

highly effective and short processing time, item must be resistant to moisture

Question 2

dry heat sterilization

Answer 2

used for products containing petroleum based liquids, no corrosive or rusting effects on instruments

Question 3

irradiation

Answer 3

high energy gamma radiation penetrates product and damages the nucleic acid, used for single use disposable items i.e. gauze, gloves

Question 4

Filtration

Answer 4

excludes organisms based on size, used for compounds that could be destroyed by heat or radiation

Question 5

gas sterilization

Answer 5

use of ethylene oxide or another volatile gas to sterile the surfaces of items or penetrate porous items; drawback-highly flammable

Question 6

plasma sterilization

Answer 6

hydrogen peroxide and peracetic acid are used as gas plasma in a chamber using radio or microwave frequency to excite gas molecules and produce free radicals which disrupt the metabolism of microorganisms; used to sterilize reusable medical equipment like endoscopes

Question 7

alcohols

Answer 7

can be used as a surface disinfectant and as an antiseptic, it kills bacteria and most viruses

Question 8

Chlorine (halogens)

Answer 8

oxidizing agents and cause damage by oxidation of essential sulfydryl groups of enzymes, antimicrobial and active against viruses, not stable needs to be made daily

Question 9

iodine and iodophors (halogens)

Answer 9

used for antisepsis of skin, mucous membranes and wound sites, betadine is used as a surgical scrub, and to prevent infections of wounds

Question 10

chlorhexidine gluconate

Answer 10

frequently used for disinfection of skin and mucous membranes, effective against most bacteria but not sporicidal. causes damage by killing plasma membrane examples are Chloraprep and Peridex

Question 11

phenolics

Answer 11

are found in some household disinfectants, in mouthwashes and soap. most active against gram positive bacteria, now widely used for showering before surgery (pHisoHex) also Triclosan

Question 12

quaternary ammonium compounds

Answer 12

are used as antimicrobial and disinfectants , non sporicidal, limited activity against non- enveloped viruses, M.Tuberculosis, stable but can not be used on living tissue

Question 13

aldehydes

Answer 13

works by forming covalent cross linkss with organic functional groups on proteins. formaldehyde and glutaraldehyde, used for sterilizing hospital instruments. Cidex, is the only liquid chemical disinfectant that can be considered a sterilant

Question 14

heavy metals

Answer 14

silver and copper have natural antimicrobial properties, metal ions combine with -SH groups on proteins

Question 15

peracetic acid

Answer 15

also can be used for environment water disinfectant, prevents biofilms and effectively controls Legionella bacteria