醫(yī)學(xué)微生物學(xué)英文版教學(xué)課件：第7章 消毒滅菌

1、Chapter 7Disinfection and Sterilization Section I Disinfection and SterilizationI. general definitionsdisinfection: is to eliminate all potentially infective microoganisms without necessarily destroying all other viable microbes .sterilization: the use of physical and/or chemical methods to eliminat

2、e all viable microbes, including viruses, fungi, bacteria and their spores. .asepsis: a state of sterility (no living bacteria) . (aseptic technique)antisepsis to inhibit the growth and reproduction of bacteria in vitro . II. Physical methods 1.heat make bacterial protein denature , bacterial DNA de

3、grade and injury cell membrane . dry heat: vegetation 80100 1hr spore 160 2hrs incineration flame hot air oven: 160170 23hrs ultra-red ray: 1 1000m microwave : 11000mm moist heat pasteurization: 61.1 62.8 30or 72 15 boiling water: 100 5 free-flowing steam and intermittent sterilization: 100 30 , 3 t

4、imes. autoclaving ： 103.4kpa(1.05 kg/ cm2), 121.3 15 -20 2. radiation 1)ultraviolet light 200-300nm interfere DNA replication dimmer of Thymine . strongest spectrum 260nm DNA absorb spectrum weak penetration : definite time and intensity stimulate skin, eyes,. application : operation room ，infectiou

5、s ward，etc 2)ionizing radiation : x-ray , -ray. Diagram of Thymine dimmer formation in DNA3. filtration filter heat-labile solution eg. Serum . toxin .antibiotics. etc. Seitz filter: KEKEK-S glass filter: G1 G2 G36 thin membrane filter 4. dry and low temperature dry low temperature ( preserve bacter

6、ia) air exhaustIII. chemical disinfection disinfectant antiseptic 1.chemical agents and mechanism 1) heavy metal salts (1)bind to SH and destroy it, inhibit activity of enzymes. (2)protein denature Thimerosal (柳硫汞): 0.1% disinfectant; 0.01% antiseptic Silver nitrate ( AgNO3): 1% 2）phenol (酚) : prote

7、in denature ，destroy cell membrane. lysol， phenol 3） aldehyde(醛) : enzyme deactivator Formaldehyde 4） alcohol(醇) : protein denature alcohol :70-75% 5)halogen(含氯消毒劑) : iodine, chlorinated lime6) aldyl agent (烷化劑) ethylene oxide7)oxidizer H2O2，KMnO4 (1) SH S-S enzyme (2) destroy amino group (3) denatu

8、re protein 8) surfactant (表面活性劑) (1) combine with phospholipid (2) increase membrane permeability e.g. bromogeramine domiphen 9)acid and alkali acetic acid； calcined lime2 Application skin： 2.5 iodine , 70 alcohol mucosa: 0.10.5KMnO4, 0.1 bromogeramine drinking water: chloride of lime patients excreta: 5 phenol , 2 lysol air: formalin spray 3. Effecting fac