Lingkungan : biotik dan abiotik

1. 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

2. Lingkungan abiotik: fisikSuhuBatas 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.

3. Temperature Figure 6.1

4. Psychrotrophs Figure 6.2

5. Bakteri yang mampu tumbuh dengan kisaran suhu minimum dan optimum yang sempit : stenotermik >< euritermik • Gonococcus : hidup dalam kisaran 30-40oC • 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

6. 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 mengalamimutasi gen.

7. 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

8. 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

9. 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.

13. kerentanan pipa

18. Types of Chemical disinfectants • Inorganic: • Iodine • Chlorine • Organic: • Alcohols • Aldehydes • Phenols • Cationic surface-active agents

22. 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

23. 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

24. Chlorine disinfectants • Powerful, Disinfect water • Particularly active against viruses • Concentrated solutions too corrosive • Usually diluted with a compatible detergent

25. 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

26. 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.

28. 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.

29. 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 • Used for heat labile instruments and cleaning • Does not harm metal instruments 1.5 % - 30 min2.0 % - 15 min

30. 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 povidoneiodine DISADVANTAGES: Occasional skin sensitivity. Inactive against bacterial spores Activity against viruses and fungi is variable and inconsistent May harm metal instruments Chlorhexidine Gluconate Hibitane vs Alkanol

32. Gaseous DisinfectionEthylene 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

33. 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