MICROBIAL CONTROL

1. MICROBIAL CONTROL

2. MICROBIAL CONTROL METHODS • Physical Control • Heat • Cold/Dessication • Radiation • Autoclave • Chemical Agents • Categories of chemicals • Household products (listed next page)

3. HOUSEHOLD PRODUCTS

4. CONTROLLING MICROORGANISMS • Decontamination- the destruction, removal or reduction in number of undesirable microbes • 4 methods of decontamination • Sterilization • Disinfection • Sanitization • Degermation

5. STERILIZATION- Removal or destruction of all viable microbes • Autoclaving, ionizing radiation • DISINFECTION- Destruction of vegetative pathogens on an inanimate object • 5% bleach, boiling water • Disinfection does not usually kill bacterial spores whereas sterilization destroys all organisms. • Difference between disinfection and sterilization? • Disinfection is only a reduction of microbial load on an object. An object that has been disinfected is less likely to transmit infection than one that hasn't but because there is only a reduction in the number of microorganisms, there is no guarantee. • Sterilization is absolute. It means that ALL of the microorganisms have either been removed or killed. A sterile object has NO viable microbial cells present.

6. SANITIZATION is a cleansing technique that removes microorganisms and debris from inanimate objects • Dishwashing, laundering clothes • Sanitizing your toothbrush is important because bacteria can build up from daily use. • DEGERMATION cleansing technique that removes microorganisms and debris from living tissue • Alcohol wipes, surgical handscrub

7. Here is a review of key concepts of hand hygiene…. • Health care-associated infections affect hundreds of millions of patients worldwide every year. Infections lead to more serious illness, prolong hospital stays, induce long-term disabilities, add high costs to patients and their families, contribute to a massive, additional financial burden on the health-care system and, critically, often result in tragic loss of life. (WHO, 2009)

8. PHYSICAL CONTROL

9. Some things to consider if using HEAT…… • Can use moist heat or dry heat • Practical Concerns in the Use of Heat: Thermal Death Measurements • Thermal death time (TDT): the shortest length of time required to kill all test microbes at a specified temperature • Thermal death point (TDP): the lowest temperature required to kill all microbes in a sample in 10 minutes • Temperature and length of exposure must be considered • Higher temperatures generally allow shorter exposure times; lower temperatures generally require longer exposure times

10. COMMON MOIST HEAT METHODS:

11. COLD/DESSICATION • The main benefit of cold treatment is the slow growth of cultures and microbes in food during processing and storage. • Cold does not kill most microbes; freezing can actually preserve cultures • Desiccation: dehydration of vegetative cells when directly exposed to normal room air • Lyophilization: a combination of freezing and drying; used to preserve microorganisms and other cells in a viable state for many years

12. RADIATION Radiationis energy emitted from atomic activities and dispersed at high velocity through matter or space • Ionizing radiation (X rays, gamma rays, electron beams) • Ionizes water to release hydroxide • Damages DNA • Non-ionizing radiation (UV, 260 nm) • Damages DNA • Microwaves kill by heat; not especially antimicrobial

13. Many foods can be effectively sterilized by utilizing the penetrating power of ionizing radiation.

14. AUTOCLAVE • Here is an example of how to clean a tattoo machine with an autoclave • http://www.youtube.com/watch?v=huStW067-jI&feature=related

15. CHEMICAL AGENTS Chemicals are divided based on their level of effectiveness and the surfaces to which they are applied. • Antiseptics: microbicidal agents harmless enough to be applied to the skin and mucous membrane; should not be taken internally. • Alcohols, mercurials, silver nitrate, iodine solution, detergents. • Disinfectants: agents that kill microorganisms, but not necessarily their spores, but are not safe for application to living tissues; they are used on inanimate objects such as tables, floors, utensils, etc. • Hypochlorites, chlorine compounds, lye, copper sulfate, quaternary ammonium compounds, formaldehyde and phenolic compounds.

16. CHEMICAL AGENTS CONT. • Chemotherapeutic agents (synthetic antibiotics): antimicrobial agents of synthetic origin useful in the treatment of microbial or viral disease. These are examples: • sulfonilamides, isoniazid, ethambutol, AZT, nalidixic acid and chloramphenicol. • Antibiotics: antimicrobial agents produced by microorganisms that kill or inhibit other microorganisms

17. These chemicals approach the ideal by having many of the following characteristics: broad spectrum, low toxicity, fact action, penetrating abilities, residual effects, stability, potency in organic matter and solubility.

18. Works Cited • Lowry, Doc. "Tattoo Machines & Guns : How to Clean a Tattoo Machine." YouTube Broadcast Yourself. 15 Nov. 2008. Expert Village. 1 Apr. 2011 <http://www.youtube.com/watch?v=huStW067-jI>. • "Microbiology in the news." American Society for Microbiology. 30 Mar. 2011. 20 Apr. 2011 <http://www.asm.org/>. • Talaro, Kathleen P., Marjorie Kelly. Cowan, and Barry Chess. Foundations in microbiology. Boston: McGraw-Hill, 2009. • Todar, Kenneth. "Control of Microbial Growth." Online Textbook of Bacteriology. 24 Apr. 2011 <http://www.textbookofbacteriology.net/control.html>. • United Kingdom. World Nuclear Association. London SW1Y 4JH. World Nuclear Association | Nuclear Power - a Sustainable Energy Resource. 1 Apr. 2011. 2 Apr. 2011 <http://www.world-nuclear.org/info/inf05.html>. • "WHO | World Health Statistics 2009." World Health Statistics 2009. 2009. World Health Organization. 24 Mar. 2011 <http://www.who.int/whosis/whostat/2009/en/index.html>.