MI03 -Chemical Control of Microbes

Disinfectant

Used to clean or sterilize inanimate objects

Antiseptic

Cleans or sanitizes living tissue

List microbe types from easiest to kill to hard to kill

From lowest resistance ot highest resistance,

Vegetative bacteria, enveloped bacteria and viruses, yeasts and fungi

non-enveloped bacteria and viruses, tuberculosis

Bacterial spores

Prions

What is bioburden? What is its effect on disinfection?

Bioburden is when blood or saliva coats a microbe, which makes it much more resistant to disinfection.

Low level disinfectant

Hospital disinfectant that has potency against HIV and HBV (both are enveloped)

Hospital disinfectant

Effective against salmonella, Staph. aureus, and Pseudomonas aeruginosa

Intermediate level disinfectant

Hospital disinfectant rated for HIV, HBV, and tuberculosis. Expected to work against enveloped viruses, fungi, and inactive bacteria.

HIgh level disinfectant

Registered for use with critical and semi-critical instruments and works on SOME spores

Can be sterilants but not for use with clinical contact instruments

Steps for disinfecting in a clinical setting

Wipe-spray-wipe - you MUST leave the disinfectant on the surface for recommended time

Halogen compounds

Disrupts protein synthesis

Broad spectrum

Often kills spores

Irritating and corrosive

Unstable

Phenols and phenolics

Phenols VERY TOXIC

Disrupts cell walls, membranes, and proteins

broad antimicrobial

Phenolics are LESS toxic than normal phenols

Intermediate level residual biocidal

NOT easy to clean - irritating

Bisguanides

Disrupts cell membranes

Chlorohexidine - common skin antiseptic and mouth rinse

Alcohols

Only ethyl and isopropyl alcohol

70% or bust

disrupts cell membranes

denatures proteins

Intermediate level disinfectant

tends to evaporate rapidly - needs to sit longer

What is isopropyl alcohol NOT effective against?

Non-enveloped viruses

Quarternary Ammonium compounds

alter membranes

low level disinfectant

does NOT kill pseudomonas

bacteriacidal against Gram positive

can be toxic in high concentrations

Quat Alcohols

Disrupt membranes

Intermediate level disinfectant

not virucidal against naked

3 for bac 2 for viruses

Aldehydes

Disrupt proteins by crosslinking

Gluteraldehyde is a sterilant or high level disinfectant

IRRITATING TO SKIN

only high level after 10 hours on surface

good for sterilization of heat labile items

surfaces must be rinsed

Hydrogen Peroxide/Peracetic acid

Hydroxyls disrupt proteins

7.5% high level, 3% antiseptic

Peracetic acid is a better sterilant - works faster

Ethylene oxide

The only gas

high level disinfectant/sterilant

high penetration and good for heat labile items

SLOW

Toxic and explosive

Retained in liquids for a long time