Disinfection in Microbiology

1.  Wide spectrum activity and effective against
all microorganism
 Should not be toxic to human
 Should be active in presence of organic
matter such as body fluid,blood and pus
 Should be effective at all ph ranges
 Should not corrode metals and not irritant to
skin
 Should have high penetrating power and
quick action
 Should not cause local irritation,cheap and
easy available

2.  Concentration of disinfectant
 Time of action
 Ph of medium
 Temperature
 Nature of the organism
 Presence of interefering substance might
reduce the activity by absorption and making
available less disinfectant to kill cells

3.  Ethyl alcohol and isopropyl alcohol
 Rapidly kill bacteria including tubercle
bacteria
 But have no virucidal or sporicidal activity
 Skin antiseptic
 Methyl alcohol is effective against fungal
spores and used in treating cabinets affected
by them
 Methyl alcohol vapour is toxic and
inflammable

4.  FORMALDEHYDE
 GLUTARALDEHYDE
 Formaldehyde
 bactericidal,sporicidal,virucidal
 Preservation of tissue for histological
examination
 Sterilise bacterial vaccine
 Prepare toxoid from toxin
 For killing bacterial culture and suspensions

6.  Effective against bacteria,viruses and spores
 For sterilisation of
cytoscope,endoscope,bronchoscope
 sterilise plastic endotracheal tubes,face
mask,metal instruments
 PHENOLS
 cresol: used in sterilisation of infected
glass ware,cleaning floors,disinfection of
excreta

8.  Savlon used in wounds ,disinfection of skin
 Bactericidal
 More active against gram positive than gram
negative bacteria
 No action on tubercle bacilli
 Good fungicidal activity

9.  more active against gram positive than gram
negative bacteria
 Bacteriostatic
 Toxic
 HALOGEN : CHLORINE AND IODINE
 Bactericidal and effective against sporing
bacteria and viruses

10.  water supplies,swimming pools,food and
dairy industries
 Bleaching powder or hypochlorite solution are
widely used for human immunodeficeincy
virus infected material
 Chloramines used as antiseptic for dressing
wounds
 IODINE: used as skin disinfectant
 Bactericidal
 Moderate action on spores

13.  ANILINE DYES:
 Skin and wound antiseptic
 Bacteriostatic and low bactericidal
 Aniline dyes are crystal violet,brilliant green
and malachite green
 More effective against gram positive bacteria
than gram negative bacteria
 No activity against M.tuberculosis
 Non toxic and non irritant to tissues

14.  acriflavine,euflavine,proflavine,aminacrine
 They are more active against gram positive
bacteria than gram negative bacteria .
 These dyes are used un clinical medicine
 GASES:
 Formaldehyde gas:
 employed for fumigation of operation
theatres,wards,laboratories
Gas is toxic and irritant when inhaled Generated
by heating formalin in a heater or by addition
of potassium permanganate (150 gm of pot.
perm. to 280ml of formalin per 1000 cu.ft. of
the room)
Used to fumigate sick rooms, OT etc.

15.  Colourless liquid
 Effective against all micro organism including
viruses,spores
 Highly penetrating gas and penetrates plastic
 Used for sterilising plastic and rubber
articles,respirators,heart lung machine,dental
equipment and clothing,disposable plastic
syringe,petridishes.
 unsuitable for fumigation of rooms because
of explosive nature

16.  condensation product of ketane and
formaldehyde
 Boiling point 163deg c
 Low penetrating gas
 Rapid action and used in 0.2%
 Effective against all microrganism ,including
viruses
 More efficient for fumigation than
formaldehyde

17.  department assembling ,producing and
distributing sterile supplies to meet the
requirement of the hospital,the department
service wards and theatres and also
undertake decontamination of medical
equipments
 Working of cssd
 1) presentation of sterile supplies to the
hospital
 2) medical equipment cleaning

18.  4) sterilisation
 5) distribution and storage
 FUNCTIONS
 1) receipt and delivery of equipment from all
areas of the hospital
 2)supply of sterile materials for dressing and
procedures carried out in wards and
departments
 3) supply of operation theatres with
necessary sterile instrument

19.  5)To dry,wrap,bag and seal items in
preparation for sterilisation
 6) To disaasemble ,clean and check for
proper function of equipment such as IV
infusion pumps,suction machines

20. CENTRAL STERILE SUPPLY DEPARTMENT
is an organized department present in the
hospital to make reliably sterilized articles
available at the required time and place for
any agreed purpose in the hospital as
economically as possible.