CHAPTER 9 Flashcards
define microbial death
permanent loss of reproductive ability under ideal environmental conditions
agents for the control of microbes should be
inexpenisve, fast-acting, stable during storage, and capable of controlling microbial growth while being harmless to humans, animals, and objects
what are the 3 levels of germicides
high-level, intermediate-level, and low-level
what do high level germicides kill
all pathogens, including endospores
what do intermediate level germicides kill
fungal spores, protozoan cysts, viruses, and pathogenic bacteria
what do low level germicides kill
vegetative bacteria, fungi, protozoa, and some viruses
what do you handle in biosafety level 1 (BSL-1)
handles pathogens that do not cause disease in healthy humans
what do you handle in biosafety level 2 (BSL-2)
handles moderately hazardous agents
what do you handle in biosafety level 3 (BSL-3)
handles microbes in safety cabinets
what do you handle in biosafety level 4 (BSL-4)
handles microbes that cause severe or fatal diseases
temperature and pH affect…..
microbial deaths
warm temps and acidic condition detergents work_____
better
3 affects of high temperature on microbial control
denature proteins, interfere with integrity of cytoplasmic membrane and cell wall, and disrupt structure and function of nucleic acids
define thermal death point
lowest temp that kills all cells in broth in 10 minutes
define thermal death time
time to sterilize volume of liquid at set temperature
