antiseptics and disinfectants

MICROBIOLOGY PRESENTATIONBY:-MOIN KHAN HUSSAIN

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ANTISEPTICS AND

DISINFECTANTS

ANTISEPTICS AND DISINFECTANTS• Germicides• Antiseptics• Disinfectants• Sterilization• Decontamination• Sanitization• Pasteurisation • Preservation

DEFINITION

DISINFECTANTS –are those germicides or chemical substances which are used to destroy or inhibit the growth of pathogenic vegetative bacteria (not their spores) on inanimate (n0nliving )surfaces such such as glassware or surgical instruments

• Ex. Formaldehyde, phenols, ethyl alcohol, soaps ANTISEPTICS-are those germicides or chemical

substances which are used to destroy the pathogenic bacteria (not the spores) on animate/ living) surfaces such as skin mucous membranes

DEFINITION

• STERILIZATION- is the process that kills all the living micro-organisms including spores, viruses and fungi.

• DECONTAMINATION- means marked reduction or destruction of viable pathogenic organisms to a level that will allow a healthy persons natural defenses to prevent any infection.

• SANITATION- means reduction in microbial load from an inanimate surface to a level set forth by public health department.

DEFINITION

• PASTEURISATION- is a process of heating milk or other liquids or semisolids for about 30min at 60-80 c, which kills the non-sporulating micro-organisms and prevents the growth of food borne pathogens for specific period of time

CLASSIFICATION OF ANTISEPTICSAct by precipitating bacterial protiens Aldehydes –formaldehyde,glutaraldehyde Phenols –cresol,lysol,chloroxylenol Alcohols –ethyl alcohol, isopropyl alcohol Heavy metals-silver nitrate,zinc calamine

ACTING BY COMPLEXING WITH SULFHYDRYL(SH) GROUPS OF BACTERIAL ENZYMES Mercurial antiseptics-mercurochrome, nitromersol

Act by oxidising the sulfhydrl(SH) group by bacterial enzymes

Chlorophores-chlorinated lime, chloramine- T,sodium hypochlorite

Iodophores –Povidine-iodine, Tincture iodine

Oxidising agents-Hydrogen peroxide, potassium permanganate, peracetic acid

ACT BY ALTERING THE PROPERTIES OF BACTERIAL CELL MEMBRANE

• Cationic surface active agents

• -chlorhexidine, cetrimide, cetylpyridinium chloride, benzalkonium chloride

Miscellaneous agents

Dyes-Acriflavine,Aminacrine,Gentian violet

Others –nitrofurazone, Boric acid

ALDEHYDES

Spectrum-G+ve ,G-ve, bact’l spores, .

viruses, fungi

Formaldehyde-37% aqueous soln-formalin

4-5%-preserve dead tissues

-pungent odour ,sensitization

Glutaraldehyde-is pungent, used as immersion disinfectant

PHENOLS • -broad spectrum –G+ve ,G-ve,tubercle

baccilli,viruses,fungi• Cresol-is a mixture of methyl alcohol• -surface disinfectant• Lysol-50% soapy emulsion of cresol• Chloroxylenol-Non-corrosive,• Dettol -4.8% Chloroxylenol, 9% terpinol,13%-

Alcohol

PHENOLS

• Eugenol –antimicrobial and analgesic

Hexachlorophene-accumulates in skin,

-cutaneous absorption and neural toxicity

Triclosan-chlorinated biphenol antiseptic

Anti-inflammatory

ALCOHOLS

Ethanol and isopropyl alcohol Spectrum-G+ve, G-ve, tubercle baccilli, viruses,fungi -they are not sporicidal Damage-corneal tissue, mucous membrane,ulcers

HEAVY METALS-Thiomersal Silver nitrate eye drops, Silver sulfadiazine-suppress bacterial growth

ZINC SALTS

• Zinc salts-mild antiseptics

• Zinc sulphate-eye drops

• Zinc oxide+calamine

Acts by complexing with sulfhydryl (-SH-) groups of bacterial enzyme

Inorganic and organic

Mercurochromme-weak antiseptic

Nitromersol –also mercurial antiseptic

CHLORINES AND CHLOROPHORES• Chlorine –effective at 0.25 ppm

• Used to disinfect drinking water

• Sodium hypochlorite solution-(Naclo)

unstable ,5% -inanimate objects

Dakins solution-(surgical chlorinated soda solution )

Chlorinated lime (bleaching powder)-30-35%

CHLORAMINE-T

• Organic chlorophore, less irrritant, stable• skin antisptic ,treatment of drinking waterOxidising agentsHydrogen peroxide-broad spectrum germicide,cleaning wounds,Abscesses, removing slough.10-20%-sporicidalH2o2 –respirators aclrylic resins

Gentian violet-roseaniline dye , G+ve bacteria and fungi.0.5-1%-chronic ulcers

Furan derivativesNitrofurazone-G+ve, G-ve ,aerobic &anaerobic b’a,

inhibit carbohydate metabolism 0.2% cream –burn dressingBoric acid-bacteristatic, weak antiseptic bladder irrigation and burns dressing

THANK YOU!!!!!MOIN KHAN HUSSAIN

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