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Invisible Germ Killers

Invisible Germ Killer

                      

Credit: Capt Holly Hess
Source: https://commons.wikimedia.org/wiki/File:U.S._Air_Force_Master_Sgt._Robin_Pugh,_an_ophthalmologist_technician_and_noncommissioned_officer_in_charge,_prepares_for_cataract_surgery_June_5,_2013,_during_New_Horizons_2013_at_the_Southern_Regional_Hospital_130605-F-FO324-002.jpg
License: CC BY-NC 3.0

Infections have always been a major issue in medical and surgical treatments. Microorganisms were discovered in 1675, but it wasn’t until the mid-1800s that scientists began to explore the link between these tiny creatures and infections. Health care workers slowly came to the realization that the surgical instruments they used could be a source of disease. Sterilization techniques have been developed that greatly lower the incidence of surgically-related disease.

Why It Matters

  • The most common sterilization techniques involve the use of either disinfectants or autoclaving. Disinfectants destroy microorganisms using chemical means to disrupt and inactivate the cells. Autoclaving involves the use of steam at high pressure to destroy the infectious agents. The high pressure involved raises the temperature of the steam to make it more effective.
  • Credit: Tom Beatty
    Source: http://www.flickr.com/photos/northcoastoutfitters/8291521701/
    License: CC BY-NC 3.0

    An autoclave you might expect to see in a dentist's office or a small lab [Figure2]

     

  • Some materials cannot be disinfected using these techniques. Treatment of solutions with disinfectant materials is not practical. Autoclaving can result in deterioration of solid materials, especially if the item is autoclaved repeatedly.
  • Ultraviolet (UV) light is a valuable alternative for many sterilization tasks. The light is created usually by a mercury vapor lamp, generating wavelengths around 250-260 nm. The UV light disrupts the DNA structure of the microorganism, so that it cannot reproduce.
  • Ultraviolet light may render some medicines inactive and ineffective. Some plastics will degrade upon repeated exposure to UV light. This technique is most effective with surface germs, since the light has limited penetrating ability.
  • Watch the video at the link below to learn more about sterilization techniques: 

https://www.youtube.com/watch?v=1xxXRbBHvBM

Show What You Know

With the links below, learn more about sterilizing with UV light. The answer the following questions.

  1. Who is known as the “Father of Antiseptic Surgery”?
  2. What is the current hospital infection rate?
  3. How does the robot system help in disinfecting rooms?
  4. What other germ-killing application for ultraviolet light has been developed?

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