BSC 160 1nd Edition Lecture 21 Outline of Last Lecture 1 Radiation 2 Filtration 3 Qualities of Chemicals Outline of Current Lecture 1 Levels of Chemical Decontamination 2 Detergents Soaps 3 Treatment Prevention of Disease Current Lecture Levels of Chemical Decontamination High level germicides Devices that are not heat sterilizable and intended to be used in sterile environments body tissue Could be sterilants Intermediate level Used to disinfect devices that will come in contact with mucous membranes but are not invasive Low level Clean surfaces that touch skin but not mucous membranes Eliminate only vegetative cells only Factors that Affect Germicidal Activity of Chemicals Nature of material being treated Degree of contamination Time of exposure Strength and chemical action of germicide Detergents Soaps Disrupt growth of microbes All things that are surfactants and impacts membrane of bacteria and fungi Soaps mechanistic action mechanical removal of microbes Dilution test Take different concentrations dip cylinder expose cylinder to disinfectant put cylinder in contact with media designed to neutralize Go back and measure growth o Requires cylinder completely immersed in chemical used o MIC Minimum inhibitory concentration Kirby Bauer In lab press down with 5 white circles Can see zone of inhibition E Test Gradient Strip instead of dots Strip has changing concentration of whatever agent Chapter 17 Treatment Prevention of Disease 17 5 17 6 Antimicrobial compounds Prophylaxis Preventing disease pregnancy Combined therapy Taking protocol using 2 drugs to help with treatment of infection Drug synergy 2 drugs working together have greater impact than drugs by themselves Antimicrobial compounds Antibiotics Antibiotic Low molecular weight compound by 1 organic organism that inhibits growth of another Synthetic Man made synthesized in lab chemotherapeutic agents Semisynthetic Made modifications to synthetic to make it slightly more effective Selective Toxicity Does mostly harm to organism you re trying to treat Toxicity needs to be aimed at organism Need to know about Prokaryotes Eukaryotes Spectrum Broad work on wide range of organisms Narrow work on subset of organisms Antimicrobial compound properties Need to be selectively toxic Wide spectrum Non allergenic Permeable Inexpensive to produce Chemically stable Difficult for microbe to develop resistance Helms thinks we should add Want to be microbial cidal and not microbial static Going to complement or enhance host system 2 3 of 9000 natural antibiotics have come from Streptomasis
View Full Document
Unlocking...