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Disinfection & SterilizationDisinfection & Sterilization

Prof. Dr. Asem ShehabiProf. Dr. Asem Shehabi

Faculty of MedicineFaculty of MedicineUniversity of JordanUniversity of Jordan

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Bacteria - Normal floraBacteria - Normal flora

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Normal Flora Human-1Normal Flora Human-1

A Large variety of microorganisms colonize humanA Large variety of microorganisms colonize humanbody throughout its entire lives.body throughout its entire lives.

Human bodies are actually composed of moreHuman bodies are actually composed of morebacterial cells than human cells.. harbor nearbacterial cells than human cells.. harbor near10101414

bacteriabacteria ,few parasites & viruses..,few parasites & viruses..A stable set of Bacteria generaA stable set of Bacteria genera (commensals),

(commensals), mostlymostlyAnaerobes (95%)..Anaerobes

(95%)..Facultative AnaFacultative Anaerobes (5%)ero

bes (5%)colonize and effect humans by:colonize and effect humans by:

Competing with pathogens & prevent their effects..Competing with pathogens & prevent their effects..

Providing vitamins or eliminating toxinsProviding vitamins or eliminating toxins (

(BacteroidesBacteroides)

)

May harm by causing diseaseMay harm by causing disease (UTI, Wound, Dental

(UTI, Wound, Dental

caries..)caries

..) .. Under certain condition.... Under certain condition.. Injury, Surgery

Injury, Surgery....

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Normal Flora Human-2Normal Flora Human-2

Skin Flora:Skin Flora:Staphylococcus spp.Staphylococcus spp. andandPropionobacteriumPropionobacterium sp.sp.

Oral Cavity and Nasopharyngeal Flora:Oral Cav

ity and Nasopharyngeal Flora:StreptococcusStreptococcus

spp., Neisseria spp., Corynebacter spp. Haemophilusspp., Neisseria spp., Corynebacter spp. Haemophilussppspp

Intestinal FloraIntestinal Flora:: The colon may containThe colon may contain 101099 to 10to 101111

bacteriabacteria per gram of feces. Mostly (95 - 99%) areper gram of feces. Mostly (95 - 99%) are

obligate anaerobes (obligate anaerobes ( BacteroidesBacteroides,,Fusobacterium,Fusobacterium,BifidobacteriumBifidobacterium,,streptococcistreptococci,,

Clostridia sppClostridia spp.).. Enterobacteracea (E..).. Enterobacteracea (E.

coli,Enterbacter, Klebsiella, Proteus ),coli,Enterbacter, Klebsiella, Proteus ),YeastYeast....Candida,Candida,

Viruses, ParasitesViruses, Parasites..

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Normal Flora Human-3Normal Flora Human-3

Urogenital FloraUro

genital Flora:: The urogenital tract isThe urogenital tract is

normallynormally sterilesterile .. the vagina and the.. the vagina and the

distal 1 cm of the urethra contain:distal 1 cm of the urethra contain:LactobacillusLactobacillus predominate in the vagina..predominate in the vagina..

Lower pH 4.5..others.Lower pH 4.5..others.

The lower partThe lower part urethraurethramay containmay containpredominantlypredominantly skin microorganismsskin microo

rganisms

including:including:StaphylococciStaphylococci,Streptococci,,Streptococci,DiphtDipht

heroidsheroids..

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IntroductionIntroduction

Definitions:Definitions: Asepsis .. Sepsis .. Antiseptic ..Asepsis .. Sepsis .. Antiseptic ..DisinfectionDisinfection/ Disinfectant .. Sanitization ../ Disinfectant .. Sanitization ..Sterilization.. Alteration of Cell MembraneSterilization.. Alteration of Cell Membrane

Permeability .. Damage of Proteins & NucleicPermeability .. Damage of Proteins & NucleicAcids..Acids..

Killing Vegetative & Spore FormingKilling Vegetative & Spore Forming Bacteria,Bacteria,Fungi, Viruses, ParasitesFungi, Viruses, Parasites

Microbial Contamination .. Pollutions ..Microbial Contamination .. Pollutions ..

BacteriostaticBacteriostatic .... BactericidalBactericidal .... MicrobiocidalMicrobiocidal ....

Refrigeration .. Deep Freezing .. Desiccation ..Refrigeration .. Deep Freezing .. Desiccation ..

FoodFood

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Physical Control of Microbial GrowthPhysical Control of Microbial Growth

Sterilization Methods:Sterilization Methods:

Direct FlamingDirect Flaming ..Incineration ....Incineration ..

Dry Heat/ Hot-air OvenDry Heat/ Hot-air Oven .. 170-180 C / 2 Hours.. 170-180 C / 2 Hours

Moist Heat/ Steam Under PressureMoist Heat/ Steam Under Pressure ....AutoclaveAutoclave

.... 121C /15 PSI/ 15 Minutes Actual Time121C /15 PSI/ 15 Minutes Actual Time

Ionizing RadiationIonizing Radiation/ High-Energy/ High-Energy ElectronElectron

Beams ..Beams .. Gamma RaysGamma Rays// Radioactive Cobalt ..10-5Radioactive Cobalt ..10-5nm.. Disposable Plastic Wares, Pharmaceuticals,nm.. Disposable Plastic Wares, Pharmaceuticals,

FoodFood

FiltrationFiltration.. Liquids .. Using Nitrocellulase.. Liquids .. Using Nitrocellulase

Membrane/ Pore SizesMembrane/ Pore Sizes 0.01-O.2um0.01-O.2um

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Ultraviolet-AutoclaveUltraviolet-Autoclave

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Use of GasesUse of Gases

Alkylating GasesAlkylating Gases: ..Ethylene Oxide+10%: ..Ethylene Oxide+10%Co2, N2Co2, N2

4-12 Hours, Fiber Endoscopes, Heart-Lung4-12 Hours, Fiber Endoscopes, Heart-Lung

Machine, Textiles, Disposable Plastic Wares,Machine, Textiles, Disposable Plastic Wares,

Formaldehyde GasFormaldehyde Gas ..Aqueous Solution 37% ....Aqueous Solution 37% ..

Formalin .. 2% Aqueous GlutaraldehydeFormalin .. 2% Aqueous Glutaraldehyde..Preservation Tissue biopsies.. Patients room..Preservation Tissue biopsies.. Patients room

as gas vaporas gas vapor

Long Exposure Time (10-24 Hours).Long Exposure Time (10-24 Hours).

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Chemical Control of Microbial Growth-1Chemical Control of Microbial Growth-1

Disinfection MethodsDisinfection Methods

Influencing Factors: Presence of Organic Materials/Influencing Factors: Presence of Organic Materials/

Contaminations.. First Cleaning ..Concentration ofContaminations.. First Cleaning ..Concentration of

Agent.. pH Medium.. Contact TimeAgent.. pH Medium.. Contact TimeMoist Heat.. Boiling Temperature/ Few Minutes,Moist Heat.. Boiling Temperature/ Few Minutes,

Pasteurization 63 C-30 Minutes, 72 C-15 SecondsPasteurization 63 C-30 Minutes, 72 C-15 Seconds

UV-LightUV-Light - 240-280 nm.. 12-24 Hours Exposure- 240-280 nm.. 12-24 Hours Exposure

Disinfectant /Antiseptics AgentsDisinfectant /Antiseptics Agents Alcohols:Alcohols: Ethanol.. Isopropanol (70-90%)Ethanol.. Isopropanol (70-90%) Aqueous IodineAqueous Iodine (3-5%) , Tincture Iodine (Alcohol-Iodine)(3-5%) , Tincture Iodine (Alcohol-Iodine)

(70%-90%).. Betadine / Iodophores-(70%-90%).. Betadine / Iodophores- Chlorhexidine.. Cetrimide.. Savlon..Chlorhexidine.. Cetrimide.. Savlon..

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Skin-Hands.. Surgical Scrub.. Mucous membranesSkin-Hands.. Surgical Scrub.. Mucous membranes

Water-Disinfection: Chlor Gas..Water-Disinfection: Chlor Gas.. Hypochlorites..Hypochlorites..

Hypochlorous Acid..Hypochlorous Acid.. (Cl(Cl22 +H+H22o +H+ + Cl- + HOCl =o +H+ + Cl- + HOCl =

HOCl..HOCl..2-3 PPM.. Kill most pathogens.2-3 PPM.. Kill most pathogens.

E. coliE. coli.. Used as indicator of water contamnation.. Used as indicator of water contamnation

Oxidizing AgentsOxidizing Agents:: OzoneOzone (0(033)..).. hydrogen Peroxidehydrogen Peroxide

Phenol Compounds.. Hexachlorophene / Dettol.. LysolPhenol Compounds.. Hexachlorophene / Dettol.. Lysol Organic AcidsOrganic Acids.. Sorbic-Benzoic Acid.. Food Preservation,.. Sorbic-Benzoic Acid.. Food Preservation,

Cosmetic.. For Control Molds/ Fungi, BacteriaCosmetic.. For Control Molds/ Fungi, Bacteria

DetergentsDetergents.. Surface-Active Agents.. Soaps, Wash-Powder.. Surface-Active Agents.. Soaps, Wash-Powder

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