Cosmetology: Microbiology and Sanitation Theory

This is microbiology and sanitation theory which talks about Bacteria, Viruses, Parasites, Immunity, Prevention for Cosmetology state board written exam.


  • Bacteria is a minute one cell micro organism that has a vegetable origin and cannot be seen with the naked eye. It is found everywhere; in the air, in the water and any matter.
  • Bacteria, germs and microbes are the same.
  • Binary Fission: is the process whereby bacteria grow, reproduce and divide into two new cells.
  • Bacteria Growth and infection: Bacteria reproduce and grow by a process called mitosis. Bacteria infections can be either local or general
    • Local infection is limited to particular area of the body like a pimple or boil. A local infection appears as a lesion containing pus and is confined to a particular part of the body.
    • General infections occur when the bacteria infect the entire body and are carried from place to place by the blood. General infections can be very serious and even deadly.
  • Bacteria are classified to: Pathogenic and non-pathogenic
    • Non-pathogenic bacteria: One of the harmless bacteria which are saprophytes that live and decompose dead matter. Example, Non-pathogenic bacteria are used to make yogurt, cheese, and some medicines.
    • Pathogenic: is a harmful bacteria that can cause disease or infection in humans when they invade the body. It is crucial that cosmetologists learn proper infection control practices and implement these activities in Salons. Pathogenic bacteria are divided into three kinds:
  • Pathogenic bacteria: is a harmful bacteria are divided into three kinds:
    1. Cocci (round shaped bacteria)
    2. Bacilli (rod shaped bacteria)
    3. Spirilla (Spiral or corkscrew bacteria)

  1. Cocci (round shaped bacteria) is classified to
    • Staphylococci (like a pimple on the face) are pus-forming bacteria that grow in clusters like bunches of grapes..
    • Streptococci (comes in Chains) are pus—forming bacteria arranged in curved lines resembling a string of beads. They cause infections such as strep throat and blood poisoning..
    • Diplococci (comes in pairs) are spherical bacteria that grow in pairs and cause diseases such as pneumonia.

  2. Bacilli: short rod shaped bacteria that causes
    • Influenza
    • Diphtheria
    • Tetanus
    • Tuberculosis
    • Typhoid Fever

  3. Spirilla are Spiral or corkscrew shaped bacteria which causes syphilis with a bacteria called Triponema Pallida, and Lyme disease with a bacteria called Borellia Burgdorferi.

  • Bacterial motility: movement is characterized by a tail-like projection called flagella or Cilia.
    • Cocci; does not have a tail, so it causes local disease.
    • Bacilli and spirilla have tails, so they cause general disease that travels through bloodstream.

  • Bacteria have two stages
    • Active or vegetative stage where bacteria grows and reproduces. It needs water, food, air, proper temperature and elimination of waste products to reproduce.
    • Spore forming or inactive stages
  • Viruses are sub microbial organisms that are able to penetrate plant and animal tissue, other bacteria and porcelain filters.
  • Bacteria and viruses can penetrate the body through body openings: nose, mouth, ears, open cuts and sores, and exchange of bodily fluids(unprotected sex).
  • Immunity is the body's ability to resist infection. Immunity is the ability of the body to destroy and resist infection. Immunity against disease can be either natural or acquired and is a sign of good health. The ability of the body to destroy pathogenic bacteria or viruses that have entered our body.
  • There are two kinds of immunity;
    • Natural immunity (the one that humans are born with) and is partly inherited and partly developed through healthy living.
    • Acquired immunity (gained by either by vaccination or by overcoming a disease) immunity that the body develops after overcoming a disease, through inoculation.
  • Human Immune Disease Carrier is a person whose immune to a disease, but can transfer the bacteria from one person to another.
  • Viruses: cosmetologist are concerned with Hepatitis A, Hepatitis B, Hepatitis C and HIV(human immunodeficiency virus).
  • Hepatitis B is the most difficult to kill on a surface
  • Parasites:
    • are organisms of animal or vegetable origins that live off of plants and animals
    • Fungi is a vegetable parasite that causes ringworm.
    • Itch mite gets under the skin and causes scabies . Head lice called pediculosis, infects the hair and scalp. 
    • A condition caused by an infestation of headlice is Pediculosis Capitis.
  • Prevention of bacterial invasion in the salon could be achieved by decontamination.
  • Decontamination is the process of removing pathogens and other substances from tools and surfaces. The removal of blood or other potentially infectious materials on an item’s surface and the removal of visible debris or residue such as dust, hair, and skin. The three means of decontamination are
    1. Sterilization
    2. Disinfection
    3. Sanitation

  • Sterilization
    • Sterilization is the strongest method of  decontamination; getting rid of all bacteria, done in the hospitals, using steam autoclave, dry heat, boiling etc.
    • Sterilization is the only method of decontamination that destroys the bacterial spores.

  •  Are chemical products that destroy all bacteria, fungi, and viruses (but nor spores) on surfaces.  Two Types of Disinfections:
    • Hospital: clean blood and body fluids. Uded on non-porous surfaces. Contro; spread of disease.
    • Tuberculocidal: Disinfection kills bacterila that causes TB.
  • Disease: abnormal condition of all or part of the body or its systems or organs, that makes the body incapable of carrying on normal function.
    • Disinfection is second only to sterilization.
    • A higher level of decontamination than sanitation is disinfection
    • Disinfectants used in salons must carry an Environmental Protection Agency (EPA) registration number.
    • Disinfection is done with the use of EPA registered disinfectant, like QUATS: Quaternary Ammonium Compound; the soiled implements are immersed in the Wet sanitizer with a lid (a container) large enough to hold implements and be filled with disinfectant.
    • A salon implement that accidentally comes in contact with blood or body fluids must be thoroughly cleaned and completely immersed in an EPA registered disinfectant.
    • Disinfectants with high pH that can cause skin irritation or burn the skin or eyes are Phenolic Disinfectants.

  • The term sanitation, also known as sanitizing, was used interchangeably to mean clean or cleaning.
  • The term sanitize is defined: A chemical process for reducing the number of disease-causing germs on cleaned surfaces to a safe level.
    • The first step in the decontamination process is called Sanitation.
    • Sanitation is a method to clean any surface that is contaminated. It is the weakest method of decontamination.
    • Also known as sanitizing; a chemical process for reducing the number of disease-causing germs on cleaned surfaces to a safe level.
    • Sanitizing is the process of removing all visible dirt and debris.
      Regulatory agencies and governmental health departments require businesses that serve the public to follow prescribed sanitary precautions.