CONTROL OF MOS BY CHEMICAL AGENTS CONTD..

G) QUATS (QUATERNARY AMMONIUM  COMPOUNDS):
           They are germicidal, cationic detergents.  They are bactericidal against Gran positive bacteria & Gram negative bacteria & are also effective against fungi to certain pathogenic protozoa. Virus appear to be more resistant than bacteria. The two popular quats are  Zephiran, a brand mane of benzalkonium chloride & Cepacol, a brand name of cetylpyridinium chloride.Eg Cetrimide . Please visit this link;http://en.wikipedia.org/wiki/Disinfectant

Uses:
 They are used as skin disinfectant, preservatives in ophthalmic solution,& cosmetic preparations. They are widely used for control of mos on  floors & walls of hospitals & public places. They are also used to sanitize food & beverage utensils in the restaurant & in food processing plants. 

Mode of Action:
They denature protein, interfere with glycolysis & membrane damage. They mostly damage the cytoplasmic membrane by altering the permeability. To know more visit the links below;
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1797692/
http://www.annualreviews.org/doi/abs/10.1146/annurev.mi.01.100147.001133?journalCode=micro
http://www.cmmonline.com/articles/the-science-of-disinfectants-7






H). GASEOUS AGENTS:  Gases are used to sterilize heat sensitive item such as syringes, sutures, catheters, etc. The major gases used are ethylene oxide(ETO), Beta- propiolactone , formaldehyde.
  • Ethylene Oxide: It is both microbiocidal as well as sporicidal. So, ethylene oxide is also called gaseous autoclave. However, it is carcinogenic  & highly explosive. So it should be used with Freon gases or carbon dioxide.  
Uses:  To sterilize heat sensitive materials like syringes, sutures, catheters, optical instrument, artificial  heart valve.
Mode Of Action: It is believed to cause alkylating reactions with enzymes & other proteins.  Please visit this link for more detail : http://en.wikipedia.org/wiki/Ethylene_oxide
http://www.medicalplasticsindia.com/mpds/2002/may/packaging.htm

  • B-propiolactone: It is occasionally used as sterilizing gas, though it is bactericidal, fungicidal, sporicidal, virucidal , it has low penetration capacity. It is carcinogenic & difficult to handle, so it is used to sterilize serum & vaccines.  please visit this link : http://highered.mcgraw-hill.com/sites/0072320427/student_view0/chapter11/chapter_capsule.html, http://www.sciencedirect.com/science/article/pii/S0032959203002784



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