LP 2 - Sterilizarea Refacut

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  • Metode fiziceMetode chimice

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  • ETUVASterilizarea ansei la bec BunsenSterilizator pentru anse

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  • STERILIZAREA PRIN FILTRARE

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  • STERILIZAREA PRIN FILTRARE

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  • 1) s aib o puternic aciune antimicrobian n concentraii relativ reduse;2) s prezinte un grad nalt de solubilitate n ap;3) s aib stabilitate n timp, sub form activ (remanen);4) s nu fie toxic pentru organismul uman, chiar n aplicaii externe;5) s nu se combine cu materii organice de pe tegumente care s-l inactiveze;6) s-i exercite efectele bactericide cu intensitate apropiat att la temperatura camerei ct i la temperatura corpului uman;7) s aib capacitate mare de penetrare;8) s nu degajeze un miros neplcut, pe ct posibil;9) s aib un cost relativ sczut.CONDIIILE GENERALE PE CARE TREBUIE S LE NDEPLINEASC UN AGENT CHIMIC DEZINFECTANT

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  • ChemicalActionUsesEthanol (50-70%)Denatures proteins and solubilizes lipidsAntiseptic used on skinIsopropanol (50-70%)Denatures proteins and solubilizes lipidsAntiseptic used on skinPhenolic compounds (e.g. carbolic acid, lysol, hexylresorcinol, hexachlorophene)Denature proteins and disrupt cell membranesAntiseptics at low concentrations; disinfectants at high concentrationsSilver nitrate (AgNO3)Precipitates proteinsGeneral antiseptic and used in the eyes of newbornsMercuric chlorideInactivates proteins by reacting with sulfide groupsDisinfectant, although occasionally used as an antiseptic on skinChlorine (Cl2) gasForms hypochlorous acid (HClO), a strong oxidizing agentDisinfect drinking water; general disinfectantTincture of Iodine (2% I in 70% alcohol)Inactivates proteinsAntiseptic used on skin Disinfection of drinking water Colorants (crystal violet, metil-violet, briliant green, metilen blue)Bacteriostatic, weak bactericideAntiseptic used on skinEthylene oxide gasAlkylating agentDisinfectant used to sterilize heat-sensitive objects such as rubber and plasticsOzone Generates lethal oxygen radicals Purification of water, sewage Detergents (e.g. quaternary ammonium compounds)Disrupts cell membranesSkin antiseptics and disinfectantsMetabolic antagonists (CO, cianures, para-fluorofenil-alanin)Interfere with normal metabolismBases and acidsPrecipitation of proteinsAldehides (formaldehide, glutaraldehide)

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  • SUBSTANCEEFFECTIVE CONCENTRATIONUSESPropionic acid and propionates0.32%Antifungal agent in breads, cake, Swiss cheesesSorbic acid and sorbates0.2%Antifungal agent in cheeses, jellies, syrups, cakesBenzoic acid and benzoates0.1%Antifungal agent in margarine, cider, relishes, soft drinksSodium diacetate0.32%Antifungal agent in breadsLactic acidunknownAntimicrobial agent in cheeses, buttermilk, yogurt and pickled foodsSulfur dioxide, sulfites200-300 ppmAntimicrobial agent in dried fruits, grapes, molassesSodium nitrite200 ppmAntibacterial agent in cured meats, fishSodium chlorideunknownPrevents microbial spoilage of meats, fish, etc.SugarunknownPrevents microbial spoilage of preserves, jams, syrups, jellies, etc.Wood smokeunknownPrevents microbial spoilage of meats, fish, etc.

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  • TYPEBRANDNAMESACTION SPECTRUMADVANTAGESDISADVANTAGESChlorineClorox. Purex(5.25'o sodiumhypochlorite)Effective against bacteria and viruses.Generally used at a 1:30 dilution ofordinary household bleach (one ounceper quart of water). Needs 5 mincontact time. Rapidly inactivated byorganic materials.Good disinfectant anddeodorizer. Inexpensive andavailable.Caustic, rapidly inactivated by organicmaterial, loses effectiveness quickly,produces carcinogenic by-products, ruinsclothing.Stabilizedchlorine dioxideOxy fresh Dent-Effective against bacteria and viruses.Rapidly inactivated by organicmaterials.Good disinfectant anddeodorizer. Diluted solutionis safe.Not readily available. Expensive.Rapidly inactivated by organic material.Concentrated chlorine dioxide fumes may betoxic to lhins tissue-Phenol.Lysol (phenol*,not benzylaininocium CI).Stericol. O-SylStaphene, 1-Stroke Environ.Effective against many bacteria, fungiand some viruses. Requires 10 min.contact tune. May not work well x thepresence of organic materialGood bacterial and viraldisinfectant. Moderate cost.High cone en nation, can irritate six eye. andlungs. Does not kill all bactena and viruses.May not work well in the presence of organicmaterialChlorhexidinegluconatesNolvasac,Phisohex.Viiosan,Hititane.Effective against most bacteria andsome yeast. Requires 10 mm. contacttune. Does not kill bacterial spores or\lntses.Effective against bactena:non-toxic. Moderate-highcost.Not effective against P;eudomonaz. Does notkill spores or viruses.

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  • TYPEBRANDNAMESACTION SPECTRUMADVANTAGESDISADVANTAGESQuaternaryammoniumcompound.Roccal-D.Quintacide.Paivoso!, Ki.or,Meiquat,CervlcideCleaner and disinfectant.Effective against many types ofbacteria, some viruses, but not againstspores or fungi. Requites contact timeo: 10 min.Effective against mostbacteria. Detergent helps toremove organic materialLow toxicity.Expensive to purchase Initially, although it isused in dilute solution (0.1* final}. Does notkill spores, fungi. Pzeudomona;, or someviruses.GlutaraldehydesWavecide,Cidex,Sporecide.Banacide.SterolEffective against bacteria, includingspores, and viruses. Wori. swell inpresence of organic material and is verystable compared to other disinfectantsVery stable and effective.Expensive. Difficult to obtain.C an irritate skin, eyes and lungs.AlcoholsEthanol is effective against a widevariety of pathogens if soaked forsufficient time (20-30 min).70% ethanol is considered mosteffective di-iniectant.Bro3d range, low cost,readily available, non-toxicRequires long contact time and evaporatesquickly so Items must be soaked in alcohol.Flammable.Iodine.Vanodine,Betadyne.Povidone,ScrubodyneEffecQve against most bacteria.Including spores, and some viruses.Requires 30 min. contact time. RapidlyInactivated by organic materials.Good disinfectant. Readilyavailable. Long shelf life.Moderate cost.Rapidly Inactivated by organic materials.Must be used in concentrated form, whichstains surfaces.Pxe oilPine-Sol HexolPine oils have some disinfectantproperties, but they are not veryeffective.Good for cleaning, low cost,non-toxic, readily available.Not effective in killing pathogens.

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