Chlorine and Iodine

Lingkungan : biotik dan abiotik
Lingkungan abiotik :
• fisik : suhu, kadar air media, nilai osmosis
media, radiasi, penghancuran sel secara
mekanik
• kimia : bakteriostatik, antiseptik,
bakterisida, germisida, desinfektan
Lingkungan abiotik: fisik
Suhu
Batas minimum dan maksimum suhu lingkungan
yang mempengaruhi proses fisiologi
• Bakteri termofil (politermik) : bakteri yang mampu
tumbuh pada suhu 40oC – 80oC dengan suhu
optimum 55oC-65oC
• Bakteri mesofil (mesotermik) : bakteri yang mampu
tumbuh baik pada kisaran suhu 5oC –60oC dengan
suhu optimum 25-40oC
• Bakteri psikrofil (oligotermik) : bakteri yang mampu
tumbuh pada kisaran suhu 0oC sampai 30oC dengan
suhu optimum 10-20oC.
Temperature
Figure 6.1
Psychrotrophs
Figure 6.2
Bakteri yang mampu tumbuh dengan kisaran
suhu minimum dan optimum yang sempit :
stenotermik >< euritermik
• Gonococcus : hidup dalam kisaran 3040oC
• E coli tumbuh baik pada kisaran 8-46oC
• Bakteri yang dipiara sedikit diatas suhu
maksimum dan dibawah suhu minimum
tidak segera mati, melainkan dalam
kondisi dormancy
Kadar air media
enzim untuk kegiatan metabolisme umumnya
termasuk kelompok hidrolase
Nilai osmosis media
larutan isotonik
larutan hipertonik : plasmolisis
larutan hipotonik : plasmoptisis
Pengaruh radiasi
bakteri fotoototrof dan fotoheterotrof mampu hidup
pada sinar tampak (390nm – 760nm).
Radiasi sinar gelombang pendek (sinar X, UV)
menyebabkan kematian sel, bakteri mengalami
mutasi gen.
Lingkungan abiotik: kimia
Antiseptik, bakteriostatik : Zat kimia yang
mampu menghambat pertumbuhan bakteri,
tidak membunuh bakteri
Germisida, bakterisida, desinfektan : Zat kimia
yang dapat membunuh bakteri
Zat antiseptik dan bakterisida tidak mampu
membunuh spora bakteri dan bakteri tahan asam
Kerusakan bakteri karena zat kimia disebabkan :
oksidasi, koagulasi protein dan penurunan
tegangan permukaan sel.
Konsentrasi zat kimia dan lama persentuhan
mempengaruhi kelompok antiseptik atau
desinfektan.
Larutan fenol 5% = desinfektan, larutan fenol 1% =
antiseptik, larutan fenol 0.5% = sumber karbon
Pseudomonas
CHEMICAL DISINFECTION
A SATISFACTORY AGENT SHOULD:
• Be active against a wide range of organisms
and spores. Only few are truly sterilizer
• Have a rapid action
• Should not be toxic or irritant to the skin
• Should be Persistent
There is no one disinfectant which can
be used to kill all micro-organisms in
all situations.
kerentanan
pipa
Types of Chemical disinfectants
• Inorganic:
– Iodine
– Chlorine
• Organic:
– Alcohols
– Aldehydes
– Phenols
– Cationic surface-active agents
Inorganic disinfectants
The halogens: Chlorine and Iodine
• Have a rapid action against vegetative
organisms and spores= true sterilizers
• Their action is annulled by foreign organic
material
membatalkan
Iodine disinfectants
The broadest spectrum of all topical anti-infectives,
with action against bacteria, fungi, viruses, spores,
protozoa, and yeasts.
• Tincture iodine:
– 2.5% iodine & 2.5% potassium iodide in 90%
ethanol.
– Best skin disinfectant
– Irritating to raw surfaces: due to its alcoholic
component
– Allergic dermatitis
• Iodophors: Solutions of iodine in non-ionic
detergents= Povidone iodine= Betadine
– Less irritating and less staining
– Less disinfectant than tincture
Chlorine disinfectants
•
•
•
•
Powerful, Disinfect water
Particularly active against viruses
Concentrated solutions too corrosive
Usually diluted with a compatible
detergent
Organic Disinfectants
• Alcohols: bactericidal: 50-70% ethanol
• Aldehydes:
– Formalin: irritant, powerful=sterilizer
– Glutaraldehyde: less irritant, not volatile, more rapid
action.
• Phenols: continued activity in organic matter as
human excreta.
–
–
–
–
–
Phenol: Toxic, expensive
Cresols: Lysol
Chloroxylenol: Dettol
Chlorhexidine: Hibitane- Alkanol
Hexachlorophane
• Cationic surface-active agents:
– Cetrimide: Cetavlon
Alcohol
• Isopropyl Alcohol 70% (or Ethyl Alcohol 90%)
ADVANTAGES:
• Causes protein denaturation, cell lysis, and
metabolic interruption.
• Degreases the skin.
DISADVANTAGES:
•
Ineffective against bacterial spores and poorly
effective against viruses and fungi.
Glutaraldehyde (Cidex)
Cold Sterilization:
• Instruments must be dry before
immersion.
• Glutaraldehyde is bactericidal,
fungicidal, viricidal, and sporicidal
• Sterilization: a 10 hour immersion.
This prolonged chemical action can be
more detrimental to surgical
instruments.
• 3 hours exposure time is needed to
destroy spores.
• If the instruments need to be
"disinfected" only, cold sterilization is
okay as disinfection will take place in
only 10 minutes.
Lysoformin
• Formaldehyde & glutaral
• Lysoformin: liquid concentrate with which any
dilution required can be made by simply adding
water (20ml + 4-8L)
• The timing depends on the concentration used:
– flexible endoscopes
– deactivation of HBV & HIV
1.5 % - 30 min
2.0 % - 15 min
• Used for heat labile instruments and cleaning
• Does not harm metal instruments
Chlorhexidine Gluconate
Hibitane vs Alkanol
Broadest spectrum
Better residual activity than iodophors
Occasional skin sensitivity
ADVANTAGES:
Rapid action
Residual activity is enhanced by repeated use
Less susceptible to organic inactivation than povidone iodine
DISADVANTAGES:
Occasional skin sensitivity.
Inactive against bacterial spores
Activity against viruses and fungi is variable and inconsistent
May harm metal instruments
Gaseous Disinfection
Ethylene Oxide Sterilization: EO Gas
• Colorless gas, available as cartridges
• Toxic and flammable, Odor similar to
ether
• Has an extremely well penetration, even
through plastics
• Microorganism destruction is caused by a
chemical reaction
• Effective sterilization is dependent on
concentration of gas, exposure time,
temperature, and relative humidity
• Powerful sterilizer: Kills all known
viruses, bacteria (including spores), and
fungi
EO Gas Sterilizer
• Is used in large hospitals, as it is
expensive, dangerous, needs more
expertise.
• Used for heat sensitive instruments:
fabrics, plastics, suture material, lenses,
endoscopes, electrical equipment and
finely sharpened instruments.
• At 20°C-25°C: sterilization takes 18hours
• At 50°C-60°C: sterilization takes 4 hours
• In Demerdash: The average of the cycle is
8-14 hours