MBIO 3010 0226 скачать в хорошем качестве

MBIO 3010 0226

Table of Contents: 00:00 - Dry Heat sterilization 01:49 - Physical Methods of Microbial Control 05:19 - In what situation is filtration the only practical way to eliminate undesirable microbes? 06:09 - Physical Methods of Microbial Control 10:23 - Physical Methods of Microbial Control 19:03 - Principles of Effective Disinfection 20:38 - Evaluating the effectiveness of a disinfectant 21:42 - Disk-diffusion method Evaluates efficacy of chemical agents Procedure Filter paper disks soaked in a chemical and placed on a culture Look for zone of inhibition around disks Fig. shows susceptibilities of 3 bacteria to different chemicals 26:53 - Chemicals can disinfect or sterilize Disinfectants Antiseptics Reacts with vital cell sites Proteins DNA Cell membrane 28:03 - Kills most vegetative cells Kills Mycobacterium at high concentrations Injure lipids of plasma membranes, causing leakage Phenol- one of the earliest disinfectants Low concentrations – local anesthetic (lozenges) Higher concentration – antibacterial (throat spray) 29:08 - 2 phenol groups connected by a bridge Disrupts membrane Hexachlorophene Active ingredient in pHisoHex Triclosan Antibacterial hand soap/lotions Banned in 2016 29:56 - Halogens 31:08 - 33:37 - Heavy Metals 36:23 - Surface-active agents 36:58 - Surface-active agents 38:09 - Aldehydes 39:39 - Chemical Sterilization 40:11 - Aldehydes 40:53 - Chemical Sterilization 42:52 - Peroxygens and other forms of oxygen 43:55 - Perishable products Spoilage rapidly Preservation goal: to slow spoilage (increase shelf-life) Preservation methods: Use preservatives Use low-temperature storage Reduce water availability 46:59 - Low-temperature storage Refrigeration: inhibits growth of pathogens/spoilage organisms Psychrotrophs, psychrophilic organisms may still grow Freezing: stops all microbial growth Some cells killed by ice crystal formation, most still viable 47:51 - Reducing Available Water by: Addition of salt, sugar increases environmental solutes Causes cellular plasmolysis (water exits bacterial cells) Some bacteria grow in high salt environments Staphylococcus aureus 49:50 - Microbiology an Introduction 51:59 - Topics 52:00 - Review . . . 53:00 - The History of Chemotherapy 54:06 - Discovery of Penicillin 1928: Alexander Fleming discovered penicillin, produced by Penicillium notatum 1940: Howard Florey and Ernst Chain performed first clinical trials of penicillin Mass production during WWII Used for the treatment of wounded soldiers and war workers 55:26 - Table 20.1 Representative Sources of Antibiotics 56:48 - Antibiotics 58:59 - Characteristics of antimicrobial drugs