Microbial Growth Control Microbial Control methods Definition of ...
Microbial Growth Control Microbial Control methods
Definition of frequently used terms -
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Sterilisation: remove all viable organisms including endospores Disinfection – killing, inhibition or removal or disease causing (pathogenic) organisms o Disinfectants – agents, usually chemical, used for disinfection, usually used on inanimate objects Sanitisation – reduction of microbial population to levels deemed safe (based on public health standards) Antisepsis – prevention of infection of living tissues by microorganisms o Antiseptics – chemical agent that kill or inhibit the growth of microorganisms when applied to tissue Chemotherapy – use of chemicals to kill or inhibit the growth of microorganisms within host tissue Agents that kill microorganisms or inhibit their growth -cide: suffix indicating that the agent kills o Germicide: includes bactericides, fungicides, algicides and viricides -static: suffix indicates that the agent inhibits growth o Includes: bacteriostatic, fungistatic
Pattern of microbial death the -
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Measure of agents killing efficiency o Decimal reduction (D-value) – time to kill 90% o Must be sure that persister cells (viable but nonculturable) are dead Thermal death point – how much time it takes to kill all the bacteria – easy to get this then to get the D point
Conditions influencing the effectiveness of antimicrobial agent activity -
Population size: the larger the population the longer it will take to kill them. The cells will be killed at the same rate but it will take longer to kill other cells in a larger population
Definition of frequently used terms -
-
Sterilisation: remove all viable organisms including endospores Disinfection – killing, inhibition or removal or disease causing (pathogenic) organisms o Disinfectants – agents, usually chemical, used for disinfection, usually used on inanimate objects Sanitisation – reduction of microbial population to levels deemed safe (based on public health standards) Antisepsis – prevention of infection of living tissues by microorganisms o Antiseptics – chemical agent that kill or inhibit the growth of microorganisms when applied to tissue Chemotherapy – use of chemicals to kill or inhibit the growth of microorganisms within host tissue Agents that kill microorganisms or inhibit their growth -cide: suffix indicating that the agent kills o Germicide: includes bactericides, fungicides, algicides and viricides -static: suffix indicates that the agent inhibits growth o Includes: bacteriostatic, fungistatic
Pattern of microbial death the -
-
Measure of agents killing efficiency o Decimal reduction (D-value) – time to kill 90% o Must be sure that persister cells (viable but nonculturable) are dead Thermal death point – how much time it takes to kill all the bacteria – easy to get this then to get the D point
Conditions influencing the effectiveness of antimicrobial agent activity -
Population size: the larger the population the longer it will take to kill them. The cells will be killed at the same rate but it will take longer to kill other cells in a larger population
