การควบคุมจุลินทรีย์ (control of Microorganisms)

1 (Control of microorganisms ) Sterilization, Disinfection, Antisepsis, Sanitation Sterilization = Disinfection = (pathogens) (vegetative cells) Antisepsis = Sanitation = Disinfectants and antiseptic Disinfectants Chlorine, hypochlorite Antiseptic alcohols, iodine solution Bactericidal.

2 Bacteristatic Bactericidal = Bacteristatic = - (cell membrane) DNA RNA (Physical) (Chemical) (Dry Heat) (Moist Heat) (Low Temperatures) (Filtration) (Radiation) / (boiling) (pasteurization) Ultra-high-temperature treatment = UHT Autoclave Tyndallization(fractional sterilization) vegetative bacterial cells, fungi virus endospore hepatitis virus (20 )

3 Sterilize 63-67 oC 30 Flash pasteurization (high-temperature short term pasteurization) : 72 oC 15 Sterilization temp. 141 C 2 -3 100 C autoclaves, pressure cookers, retorts 121 C 15 / . 15-30 Clostridium Bacillus stearothermophilus semisolidTemp.

4 ~ 80-100 oC 30 1 3 cytoplasm sterilization hot-air oven incineration. Burner flames : pincets, inoculating loops, the mouth of culture tubes Electric loop incinerators furnaces used to destroy disposable items, soiled dressings, tissue specimens etc. at 800 C to 6500 C 160 C 2 . Temp.

5 ~ 4oC mesophiles thermophiles psychrophiles Temp. ~ -10 -20 oC -80 oC vaccines, antibiotics solution serum membrane filters plastic polymer cellulose esters pore sizes ( m) high efficiency particulate air (HEPA) filters m laboratory hoods DNA ultraviolet 260 nm DNA DNA thymine dimers Gamma rays Co -60 free radical (OH-)

6 DNA sterilization Phenol Halogens Alcohol Heavy metal Surface active agents Gaseous sterilants Oxidizing agent Antibiotic Phenol, orthocresol, orthophenylphenol, hexachlorophene Phenols oxidize chlorine sodium hypochlorite, calcium hypochlorite, chlorine gas Sodium Hypochlorite 10 -20% disinfectant Halazonetablets (parasulfonedichloroamidobenzoicacid) Tincture of iodine ( iodine solution in 70% alcohol) Betadyne vegetative cells bacteria & fungi spores : Ethyl, isopropyl 70%-90% (Mercury), (silver), (zinc), (arsenic), (copper) Hg Mercuric chlorides : Mercurochrome = Ag 1% silver nitrate : Zn Zinc oxide.

7 Copper sulfate bactericidal : Quaternary ammonium- NH4+- plasma membranes- gram-positive bacteria- Formaldehyde : Ethylene oxide : CO2 10 % : 90% Hydrogen peroxide oxidizing agents bacteria, bacterial spores, viruses fungi Hydrogen peroxide (H2O2) : 3% = antiseptic Potassium permanganate (KMnO4) : (Antibiotic Spectrums) Broad-spectrum: Tetracycline gram-positive bacteria gram-negatives Chlamydia, Mycoplasmas Rickettsiae Narrow-spectrum.

8 2-3 Vancomycin gram-positive cocci(Staphylococci Enterococci). Antimicrobial susceptipility(sensitivity) tests Disk diffusion: 35-37 C 24-48 hrs. Dilution method antibiotic Minimum Inhibition Concentration (MIC): Minimum Bactericidal Concentration (MBC): MBC MIC (Mode of action)1.

9 Transpeptidase cross-linking peptidoglycan Pinicillin, cephalosporins vancomycin2. cell membrane: membrane semi-permeable polymyxin3. protein: translation aminoglycosides4. nucleic acid: Nalidixicacid DNA replication rifampicin transcription