MICRO 3050 Exam 3 QUESTIONS AND ANSWERS WITH COMPLETE SOLUTIONS VERIFIED GRADED A++

MICRO 3050 Exam 3 QUESTIONS AND ANSWERS WITH COMPLETE SOLUTIONS VERIFIED GRADED A++ Leave the first rating Practice questions for this set Terms in this set (107) medical problems with biofilms: -form on medical devices -cause disease -dental caries (plaques, ferments and degrades teeth) -pneumonia industrial problems with biofilms: - interfere with fluids distribution - potential corrosion quorum sensing: ability of bacteria to sense the presence of other bacteria via secreted chemical signals sterilization: - destruction or removal of all viable microorganisms (absolute condition) - sterilants decontamination: - removal of blood or other potentially infectious materials on an item's surface - DOES NOT STERILIZE disinfection: - killing, inhibition, or removal of pathogenic microorganisms - disinfectants: used on inanimate objects - DOES NOT STERILIZE sanitation: - cleaning process - reduction of microbial populations to levels deems safe (based on public health standards) - sanitizers antisepsis: - prevention of infection of living tissue - antiseptic (germicides): chemical agents that kill or inhibit growth of microorganisms when applied to tissue chemotherapy: - use of chemicals to kill or inhibit growth of microorganisms within the host tissue what are the 4 physical methods to control micros? 1. heat (moist and dry) 2. low temperature 3. radiation 4. filtration moist heat and its types: - better that dry heat because it has water with more penetrating power - destroys bacteria, fungi, and viruses 1. boiling: will not always destroy endospores, no does not necessarily sterilize 2. pasteurization: only a disinfection methods, reduce microbial load 3. autoclaving pasteurization: - controlled heating at temperatures well below boiling - used for wine, milk, and other beverages - kills pathogens present and slows spoilage - reduces the total microbial load - does not sterilize autoclave: - steam under pressure - means of sterilization (kills endospores) - pressure 15 psi, temperature 121C steam, time 15-20 mins dry heat sterilization: - less effective than moist heat sterilization - dry heat sterilizer requires higher temperatures and longer exposure times (160- 170C for 2-3 hr) - flaming (incineration): sterilization that does not last very long freezing: - -20C - stops microbial reproduction due to lack of liquid water - some microorganisms killed by ice crystal disruption of cell membranes refridgeration: - 4C - slows microbial growth and reproduction ultraviolet (UV) radiation: - non-ionizing radiation - most bactericidal wavelength is 260 nm - causes thymine dimers in DNA to break and weaken it - poor penetrating power - limited to disinfection of surfaces, air, and water - does not penetrate glass, plastic, dirt films, etc ionizing radiation: - beta, gamma, and x-rays - penetrates deep into objects - cold sterilization: antibiotics, medical supplies, food