Microbiology & dectamination

• Types of micro-organisms


  • Bacteria
  • Fungi
  • Virus
• Cross Infection


  Transfer of micro-organisms from one person to another e.g. patient to patient
• Disinfection


  Chemical killing of bacteria and fungi but not all viruses or spores
• Sterilisation


  Killing of all micro-organisms; bacteria, fungi, viruses, and spores
• Decontamination


  Range of processes; cleaning, disinfection and/or sterilisation which render instruments & equipment safe for reuse
• Zoning


  Having separate clean and dirty zones to reduce the risk of cross infection
• Pathogenic


  Micro-organism able to cause disease
• Asepsis


  The absence of all living pathogenic micro-organisms
• Diseases caused by pathogens


  • Hep B
  • TB
  • Hep C
  • Common cold
  • Flu
• A micro-organism capable of causing disease is described as pathogenic
• A micro-organism which can cause disease is said to be pathogenic
• Standard Precautions


  Treat all patients as infectious
• SICPS


  Standard Infection Control Precautions
• How to apply SICPS


  • Treat all patients as infectious
  • Follow practice Cross Infection Policy
  • Follow the same high standard of infection control for all patients
• Prion


  Abnormal protein unable to be destroyed by autoclaving
• Carrier


  A person who has no symptoms of a disease but may pass it on to another person
• Validation


  A documented quality assurance procedure applied to each stage of the decontamination process to ensure the procedure is consistently carried out to a required standard
• It is important to keep records in relation to cross infection for validation (proof)
• Records to keep in relation to infection control


  • Waste consignment notes
  • Data reader or print outs from autoclave/WD
  • Logbooks
• Types of micro-organisms


  • Bacteria
  • Fungi
  • Virus
• Examples of micro-organisms


  • Streptococcus mutans
  • Candida albicans
  • Herpes simplex
• Diseases caused by micro-organisms


  • Dental caries
  • Oral thrush
  • Denture stomatitis
  • Angular cheilitis
  • Herpes labialis (cold sore)
• Micro-organisms and their diseases


  • Streptococcus Mutans - Dental caries
  • Candida Albicans - Oral thrush, Denture stomatitis, Angular Cheilitis
  • Herpes Simplex - Herpes labialis (cold sore)
• Micro-organisms and their diseases


  • Lactobacillus - Dental caries
  • Borellia Vincentii - ANUG
  • Legionella - Legionnaires Disease
• Candida albicans causes denture stomatitis
• Candida albicans is mainly responsible for Angular cheilitis
• Herpes simplex causes a cold sore
• Streptococcus mutans is mainly involved in dental caries
• Bacterial shapes


  • Cocci-round
  • Bacilli-rod
  • Vibrios-comma
  • Filamentous-thread like
  • Spirochaetes-spiral
• Bacilli are rod-shaped bacteria
• Cocci bacteria are round in shape
• Lactobacillus is a bacterium
• Oral thrush is not caused by a virus
• SDCEP


  Scottish Dental Clinical Effectiveness Programme
• The correct time, temperature, and pressure for an autoclave is 3 minutes, 134C, 2.2 bar
• A manual test of an autoclave should be carried out and recorded once per day
• Values to record during a manual autoclave test


  • Time
  • Temperature
  • Pressure
• Procedure if a fault occurs with the autoclave


  1. Stop autoclave immediately

  2. Report

  3. 'Out of use' notice on door

  4. Use alternative autoclave

  5. Contact engineer or identify fault from manual
• Washer disinfector cycle


  1. Flush

  2. Wash

  3. Rinse

  4. Thermal Disinfection

  5. Dry
• The washer disinfector needs to reach 80°C for 10 minutes or 90°C for 1 minute at the 'thermal disinfection' stage