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MICROBIOLOGY – ALCAMO

MICROBIOLOGY – ALCAMO. LECTURE: Chemical Methods of Control . Health Care Conditions in the1800’s. Hospitals rarely had _____________ Garbage and _____________ were dumped in a pit right outside _____________ wiped their hands and instruments on their jackets and pants

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MICROBIOLOGY – ALCAMO

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  1. MICROBIOLOGY – ALCAMO LECTURE: Chemical Methods of Control

  2. Health Care Conditions in the1800’s • Hospitals rarely had _____________ • Garbage and _____________ were dumped in a pit right outside • _____________ wiped their hands and instruments on their jackets and pants • Bed sheets were rarely changed and infection was rampant • 1/3 of women giving birth died of puerperal fever – _____________caused by Streptococcus

  3. Health Care Conditions in the1800’s • A Hungarian doctor – _____________ _____________– noticed: • More puerperal fever in maternity wards tended by doctors fresh from _____________ cadavers • Less puerperal fever in maternity wards tended by midwives • He thought disease was _____________ _____________ hands and made hospital workers wash their hands • This _____________ the death rate among maternity patients significantly

  4. Health Care Conditions in the1800’s • Other doctors _____________ Semmelweis’s conclusions because it put the blame on them • After he died, Pasteur came out with the _____________ _____________ _____________ • Doctors began to finally realize that infectious MO’s could be _____________ by clothing, utensils and instruments • They began using chemical _____________ and _____________ and the death toll declined

  5. Health Care Conditions in the1800’s • In the 1860’s _____________ _____________ established the principles of aseptic surgery • He used _____________ _____________ to kill MO’s in operating rooms • Reduced the death rate post-surgery from 45% to 9%

  6. Lister Video • http://www.mefeedia.com/news/29703360

  7. Chemical Agents of Control – Terms To Know • Most chemical agents can only reduce the # of MO. _____________ is unusual. • Two Categories: • _____________ : Use on living tissues - mild or very diluted chemicals • _____________ : Use on objects – strong or concentrated chemicals

  8. Chemical Agents of Control - Terms To Know • _____________ Agent – kills MO’s • _____________ Agent – temporarily prevents further multiplication of MO’s without killing them • _____________ (putrid) – contamination of an object by MO’s: • _____________ – MO infection of the blood • _____________ – against infection • _____________ – free of contaminating MO’s

  9. Chemical Agents of ControlTerms To Know • _____________ – to reduce the MO population to a safe level determined by public health standards • _____________ – to remove MO’s from the surface • - cidal agents – kill Mo’s: • Fungi_____ • Viru_____ • Spori_____

  10. What Makes a Good Disinfectant • It must kill MO’s • Be ______________ to humans and animals • Be soluble in water • Get its job done in a short time • Should ____________ surfaces well • Should not ____________ instruments • Should be inexpensive and easy to obtain

  11. Important Chemical Agents - Halogens • ____________ are highly reactive elements whose atom have 7 electrons in their outer shell • ____________ and Iodine – Very Reactive • Cause Cell Death by Oxidation – • Oxygen is released and then combines with and inactivates proteins (enzymes)

  12. Important Chemical Agents - Halogens • ____________ Disinfectant that can be used alone as gas or in a Solution with water • Used in municipal water supplies to keep bacterial populations low • 6 – 10 Drops/Gal Clear Water/1 hour = Drink • Available as calcium hypochlorite – used for wounds in WWI and WWII

  13. Important Chemical Agents - Halogens • Available as ________________________– bleach to disinfect water (swimming pools) and sanitize factory equipment • Laundry bleach most available and excellent means of MO control • Do not combine bleach with other chemicals - small but lethal amounts of Cl gas may be released!!!!

  14. Important Chemical Agents - Halogens • ____________is effective against • Gram-positive and Gram-negative bacteria • Many viruses • Fungi • Protozoa • Not effective against spores

  15. Important Chemical Agents - Halogens ____________ Usually an ____________ • 2% in water or alcohol (Tincture) good for wounds • If solvent evaporates tissue damage • For water disinfection use 18 – 20 Drops/Gal Clear Water/1 hour = Drink • Iodifors – iodine mixed with detergent • ____________ – for local wounds

  16. Important Chemical Agents - Phenol • Has been a key ____________ since Joseph Lister used it • Remains the standard against which other ____________are evaluated • It acts by ____________ proteins in the cell membranes of MO’s • But, it is expensive, has a strong odor, and is ____________ to the skin

  17. Important Chemical Agents - Alcohol • Either ____________ or ____________ • 70% Ethyl alcohol preferred • Causes denaturation and desiccation • But requires long exposure, limited effect

  18. Important Chemical Agents - Heavy Metals • ________________________with a large molecular weight: • Silver, Mercury, Copper, Lead, Zinc • Can be used as either an antiseptic or a medicine • Cause ____________ of proteins (enzymes) • Can be very __________ to host

  19. Important Chemical Agents - Heavy Metals • Mercury: • ________________________was used by the Greeks and Romans for treating skin diseases • ____________is very toxic to the host, so it is now combined with carrier molecules to make it less toxic • Mercurochrome • Merthiolate • Metaphen

  20. Important Chemical Agents - Heavy Metals • ____________: • Potent inhibitor of algae • Copper sulfate is an algaecide used in swimming pools and municipal water supplies

  21. Important Chemical Agents - Heavy Metals • Silver: • ________________________– use -ful antiseptic and disinfectant • If it is a strong dilution – used for chemical cautery • If it is a weak dilution – used in a newborn’s eyes to prevent bacterial infection by Neisseriagonorrhoeae • ____________: Calamine Lotion (antiseptic, anti-itch) • ____________: PeptoBismol (anti-diarrheal)

  22. Important Chemical Agents Hydrogen Peroxide • ____________ and ____________– used as a rinse in wounds and scrapes • Area foams as catalase in tissues breaks down H2O2 to oxygen and water • This results in a highly reactive form of oxygen – toxic to MO’s

  23. Important Chemical Agents - Soap • ____________ is made of fatty acids combined with sodium hydroxide – high pH bad for certain MO’s • Soap is also a wetting agent that solubilizes particles clinging to a surface • ____________ also removes skin oils and MO’s slide off skin

  24. Soaps Video • http://www.google.com/url?sa=t&source=video&cd=9&sqi=2&ved=0CH8QtwIwCA&url=http%3A%2F%2Fvideo.google.com%2Fvideoplay%3Fdocid%3D-3210455528645505714&rct=j&q=chemical%20disinfection&ei=gXSjTc-QPMi-0QGAlaDQBA&usg=AFQjCNH14lMibDqfMas5Nz5ZNV34-Y9njg&cad=rja

  25. Important Chemical Agents - Ethylene Oxide • A small compound with excellent penetration capacity and ____________ ability due to oxidation • Very Dangerous – ______ and explosive • Used in production of sterile supplies and by NASA to sterilize space capsules

  26. Ethylene Oxide Video • http://www.youtube.com/watch?v=-ICBQg9tcT8

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