History of Sterilization

STERILISATION

TOPICS Introduction -Definition -History -Terminology  Classification of sterilizing agents 

STERILIZATION & DISINFECTION 

Sterilization is defined as ´the process by which an article , surface or medium is freed of all living microorganisms either in the vegetative or spore state.µ

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Disinfectionn means ´the destr Disinfectio destructio uctionn or removal of all pathogenic micro organisms capable of giving rise to infection but not necessarily resistant spores.µ

WHY    

STERILISATION???

Micro organisms are ubiquitous. To prevent contamination by extraneous organisms. In surgery, to maintain asepsis. In food and drug manufacture to ensure safety.

HISTORY 

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Oliver Wendal Holmes(1843) and Ignaz Semmelweis(1846) Semmelweis(184 6) concluded that puerperal sepsis was transmitted by contaminated hands of Obstetricians, nurses, medical students. Can be prevented by washing hands in aseptic solution.

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LOUIS PASTEUR(1822-189 PASTEUR(1822-1895 5) ² Father

of modern Microbiology. Proposed ´GERM THEORYµ In the course of these studies, he introduced techniques of sterilization and developed the steam sterilizer, hot air oven and autoclave. Pasteurization.

 JOSEPH

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Fathe therr of of Anti Antisep septic tic LISTER ² Fa

Surgery. In 1866, Lister Lis ter suggested antiseptic antiseptic surgery which involved the use of ´CARBOLIC ACIDµ. Pronounced drop in mortality and morbidity observed. Marked the Beginning of Modern aseptic conditions from the era of Laudable pus.

 JOHN

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TYNDAL (19th century)

²Tyndallisation (Intermittent sterilization). Student of Pasteur. Tyndallisation essentially consists of boiling the substance at 1000C for 15 minutes for three days in a row. Used for media containing sugars and gelatin. It is generally effective, but its reliability is not considered 100% certified.

TERMINOLOGY TERM

DEFINITION

Anti An tissep epti tics cs

Subs Su bsta tanc nces es wh whic ich h ei eith ther er ki kill ll mi micr cro o org orga ani nism smss of of in inh hib ibit it th thei eirr gr gro owt wth h

Disinfectants

Compounds that kill micro organisms( except bacterial endospores)

Asepsis

Technique that is employed in preventing infections from gaining access to an infected tissue.

Cle lea ani nin ng

Clea ean ning is a soil re rem movin ing g pro roccess th tha at re rem moves many micro organisms . It a necessary prerequisite to sterilization & disinfection.

Sterilant

Chemical ag agents that destroy all micro or organisms in including sp spores.

Ger erm mic icid ide e

Chem emiical or or physic ica al ag agen entt th tha at de desstroys most or organisms bu but not endospores, used on skin and inanimate objects.

Sporocide

Gener era all lly y a chem emiical agent th tha at des desttroys bo both th ba baccter eriial & fu fun ngal spore ress

Fungicide

Chemical substances that destroy fungi

Virucide

Chemical agents that destroy viruses

Bactriostat

Chemical agents that inhibit bacterial growth

Saniti tizzer

An agent nt,, usuall lly y a de dete terg rgen entt that red edu uces the no no.. of bacte terria to a safe lev evel el

WHICH

METHOD OF STERILISATION??

The method of sterilization to be employed depends on :  The purpose for which it is carried out.  The material which has to be sterilized.  Nature of micro organisms to be destroyed.

CLASSIFICATION OF STERILIZING AGENTS  Broadly

classified into :  Physical agents  Chemical agents

FLAMING SUNLIGHT DRY HEA EAT T

INCENIRATION

DRYING HOT AIR OVEN HEA EAT T

AT TEMP < 100C PHYSICAL

AGENTS

FILTERATION MOIST HEA EAT T

AT TEMP 100C

IONISING

AT TEM TE MP > 100C

RADIATION NON IONISING ULTRASONIC & SONIC

PHENOLS

HALOGENS

SURFACE ACTIVE AGENTS

DYES

METALLIC SALTS

ALDEHYDES

ALCOHOLS

CHEMICAL AGENTS

GASES

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