Published on August 14, 2013
Sterilization Is the complete destruction of all microorganisms, including cells, spores, and viruses. When something is sterile, it is devoid of microbial life. Sterilization of objects can be accomplished by dry heat, autoclaving, gas, various chemicals and certain types of radiation.
Disinfection Is the destruction or removal of pathogens from nonliving objects by physical or chemical methods. Pasteurization is a method of disinfecting liquids. Disinfectants-are chemical agents used to eliminate pathogens Antiseptics are solutions to disinfect skin and other living tissues. Sanitation-is the reduction of microbial populations to levels considered safe by public health standards.
Microbicidal agents Microbicidal agents-are disinfectants to kill microbes Bactericidal agents are disinfectants that kill bacteria but not necessarily bacterial endospores Sporicidal agents- to kill bacterial endospores Algicidal agents-are used to kill algai in swimming pools and hot tubs. Viricidal agents to destroy viruses Pseudomonicidal agents kill pseudomonas species Tuberculocidal agents- kill M.tuberculosis
Microbistatic agent Is a drug or chemical that inhibit the growth and reproduction of microorganisms. A bacteriostatic agent is one that specifically inhibits the metabolism and reproduction of bacteria.
Sepsis-refers to the presence of pathogens in blood or tissues Asepsis means the absence of pathogens Antisepsis-is the prevention of infection Antiseptic technique- developed by Joseph Lister in 1867,refers to the use of antiseptics. Sterile technique-is practice to exclude all microorganisms from a particular area, so that the area will be sterile.
Using physical methods to inhibit microbial growth The physical methods commonly used in hospitals, clinics and laboratories include heat, the combination of heat and pressure, desiccation, radiation, sonic disruption, and filtration.
Heat Is the most practical, efficient and inexpensive method of sterilization of those inanimate objects and materials that can withstand high temperatures 2 factors: A. Temperature B. Time -determine the effectiveness of heat for sterilization
There is a considerable variation fro organism to organism in their susceptibility to heat; pathogens usually are more susceptible than nonpathogens .
Dry Heat Dry heat baking in a thermostatically controlled oven provides effective sterilization of metals, glasswares, some powders, oils and waxes.
Moist heat Heat applied in the presence of moisture , as in boiling or steaming, is faster and more effective than dry heat and can be accomplished at a lower temperature; thus it is less destructive to many materials that would damaged at higher temperatures.
Cold Refrigeration merely slows the growth of most microorganisms; it does not completely inhibit the growth.
Desiccation The process of being thoroughly dried
Radiation The UV rays, which do not penetrate glass and building materials, are effective only on surfaces. They penetrate cells and thus can damage DNA .
Filtration Filters of various pore sizes are used to filter or separate cells, large viruses, bacteria and certain other microorganisms from the liquids or gases in which they are suspended.
Gaseous atmosphere It is possible to inhibit growth of microorganisms by altering the atmosphere in which they are located
Using chemical agents to inhibit microbial growth Chemical disinfection refers to the use of chemical agents to inhibit the growth of pathogens, either temporarily or permanently.
Various factors affect the efficiency or effectiveness of a disinfectant Prior cleaning of the object or surface to be disinfected The organic load that is present, meaning the presence of organic matter on the materials being treated The bioburden, meaning the type and level of microbial contamination The concentration of the disinfectant The contact time, meaning the amount of time that the disinfectant must remain in contact with the organisms in order to kill them. The physical nature of object being disinfected Temperature and ph
Characteristics of an ideal chemical antimicrobial agent It should kill a wide variety of microorganisms It should be fast acting, contact time should be short Should not be affected by the presence of organic material Must be nontoxic to human tissues and noncorrosive and nondestructive to materials It must be soluble in water and easy to apply Should be inexpensive and easy to prepare Should be odorless It must be stable both as a concentrate and as a working dilution.
Inhibiting Microbial Growth in vitro. CLS 311: Basic Microbiology. ... of pathogenic microorganisms to the point where they no longer cause disease.
that acetaldehyde caused leakage of electrolytes from fungal mycelia (17). Ethanol completely inhibited the growth of all the evaluated decay microorganisms.
... viable even after drying but they cannot reproduce i.e. desiccation will inhibit the growth of microorganisms. ... Inhibiting Microbial Growth in vitro
The in vitro study of ursolic acid and oleanolic acid inhibiting cariogenic microorganisms ... microorganisms and biofilms. ... growth of cariogenic ...
Inhibiting Microbial Growth in vitro. ... viable even after drying but they cannot reproduce i.e. desiccation will inhibit the growth of microorganisms.
Inhibiting Microbial Growth in vitro CLS 212 ... Disinfection Disinfection is reducing or eliminating the number of pathogenic microorganisms to the point ...
Inhibiting Microbial Growth in vitro. CLS 212: Medical Microbiology. Microbicidal or Microbistatic ?. Microbicidal Microbicidal is the process or an ...
... were evaluated in vitro. Listerine inhibited the growth of ... inhibiting growth of Listerine was ... of the growth of microorganisms.
In Vitro Efficacy of Plant Volatiles for Inhibiting the Growth of Fruit and Vegetable Decay Microorganisms IMADE S. UTAMA,*,† RON B. H. WILLS ...