Chapter 8 Microbiology Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Important People in Microbiology Anton Van Leeuwenhoek Magnifying glass Saw microorganisms from teeth for the first time Louis Pasteur Process of fermentation Proved bacteria causes disease Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Important People in Microbiology Robert Koch Koch’s Postulates Organism must be present in all cases of the disease Organism must be isolated in pure culture Organism must be capable of producing the disease in another person or animal Organism must be recovered again in pure culture Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Groups of Microorganisms Bacteria and virus groups Gram stain used to differentiate Gram positive if they keep their dark purple color Gram negative if they lose the color Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Bacteria Need for oxygen Aerobic bacteria must have oxygen to grow and live. Anaerobic bacteria are destroyed in the presence of oxygen and live only without oxygen. Facultative anaerobic bacteria grow with or without oxygen present. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Bacteria Colonies of bacteria Pairs Clusters Chains Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Diseases Caused by Bacteria Tuberculosis Bacteria is found in the lungs Fatigue, fever, weight loss, persistent cough Airborne; dental personnel must wear masks Detected by a skin test and/or chest x-ray Treatment is antibiotics or other drugs Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Diseases Caused by Bacteria Diphtheria Severe throat infection and fever Pertussis Respiratory disease Mainly affects infants and young children Tetanus Stiffness of the jaw (“lockjaw”) Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Diseases Caused by Bacteria Strep throat Very common Sore throat, fever, general malaise Streptococcus mutans, a species of the same bacteria; implicated in dental caries and endocarditis Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Diseases Caused by Bacteria Staphylococcal infections Bacteria groups grow in clusters: Staph infection Gangrene Toxic shock syndrome Venereal diseases Some forms of pneumonia Antibiotics are the first line of treatments. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Diseases Caused by Bacteria Anthrax Humans can get disease through cuts in the skin or by eating diseased meat Powder form symptoms within 1 to 6 days; fever, weakness, dry hacking cough prevention by vaccination or antibiotic treatment before symptoms Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Diseases Caused by Bacteria Chlamydiae Group of microorganisms that behave like bacteria and are small in size, somewhere between bacteria and viruses Responsible for genital, eye, and lymph node infections Most common sexually transmitted disease in the United States Antibiotics to treat Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Protozoa Just below visibility of the naked eye Always dividing and changing shape Flagella Many have this long, threadlike appendage Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Diseases Caused by Protozoa Amebic dysentery Severe diarrhea, abscesses may develop in liver Prevalent in countries where the drinking water is contaminated and overall poor hygiene conditions prevail Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Diseases Caused by Protozoa Periodontal disease (protozoa and bacteria) Both are found in inflamed tissue around the tooth Protozoa is found in the plaque in the periodontal pockets around the tooth Treatments include removal, cleaning of plaque and tissue, and oral hygiene maintenance Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Diseases Caused by Protozoa Malaria Symptoms during the first two weeks Fever and soreness at point of entry Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Rickettsiae Parasites cannot live outside a host Lice, fleas, ticks, and mites transmit the disease to humans Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Diseases Caused by Rickettsiae Head lice Common among children in schools Transmitted easily through direct contact Eggs reproduce in hair shafts Treatment is medicated shampoo and cleaning of everything, such as bedding, brushes, and clothing, with very hot water Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Diseases Caused by Rickettsiae Rocky Mountain spotted fever Rare, curable Small pink dots appear Typhus Rare, treatable Severe headache, back and limb pain, constipation, rash, and confusion Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Yeasts and Molds Includes bread yeast, mushrooms, and bread molds Cannot be killed by bacterial antibiotics (made from mold but does not act on it) Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Diseases Caused by Yeasts and Molds Candidiasis Covered by mucus in areas such as the inside of the mouth or the vaginal area Treated by antibiotics Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Diseases Caused by Yeasts and Molds Tinea (“athlete’s foot”) Itching and cracking of the foot Treatment in form of creams, ointments, and lotions Tinea unguium White patches on the toe or fingernail Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Viruses Must live inside hosts Antibiotics cannot kill the virus Treatment is primarily to ease the symptoms for the patient’s comfort Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Diseases Caused by Viruses Measles Rash, fever Spread by airborne droplets of nasal secretions Mumps Swelling of the parotid (salivary) glands on one or both sides Spread by airborne droplets Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Diseases Caused by Viruses Rubella or German measles Rash on face that may spread to trunk and limbs Only serious when it affects women in early stages of pregnancy (may cause birth defects) Vaccines are highly effective and given to most infants at age 15 months Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Diseases Caused by Viruses Poliomyelitis or polio Attacks the central nervous system (severe paralysis is a possibility) Vaccine given at age 5 years. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Diseases Caused by Viruses Chicken pox Very common and contagious in children Rash and fever Spread through airborne droplets Usually only contract once in a lifetime Before age 10 years is better than as an adult Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Diseases Caused by Viruses Common cold and influenza Treatments for fever, upset stomach, headache, body ache Cold is spread through airborne droplets, contact with contaminated objects, or hand-to-hand contact Flu vaccines are successful in 60% of patients Flu is contagious from 12 to 72 hours after symptoms appear Flu is spread through airborne droplets Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Diseases of Major Concern to the Dental Assistant Herpes simplex virus (HSV) Herpes simplex virus I (HSV I) is associated with infections of the lips, mouth, and face Herpes simplex virus II (HSV II) is associated with the genital area (can also be found in oral cavity) Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Diseases of Major Concern to the Dental Assistant Treatment of HSV I depends on its type, site, and severity Dental teams may suggest to reschedule patient if the sores are apparent (primarily for patient comfort, although some offices may have policies) Many treatments readily available Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Diseases of Major Concern to the Dental Assistant Bloodborne diseases Hepatitis B Human immunodeficiency virus (HIV) Brain damage and dementia may occur May develop into acquired immune deficiency syndrome (AIDS) No cure Much research is being done to find a cure Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Diseases of Major Concern to the Dental Assistant High risk behavior Injuries or sticks with sharp objects contaminated with blood or body fluid Multiple sexual partners; unprotected sex Sharing contaminated needles Exposure to non-intact skin or open wound with contaminated blood or body fluid Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Diseases of Major Concern to the Dental Assistant Viral hepatitis Hepatitis A and E Transmitted by personal contact or ingestion of contaminated water or food Vaccines and boosters are available for children in areas at high risk Hepatitis B (major dental concern) Transmitted mainly through needles and syringes May or may not have symptoms Loss of appetite, abdominal pain and tenderness, fever, weakness, muscle pain, and jaundice Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

How the Body Resists Diseases Infection Pyogenic membrane: dam built around the infected area preventing it to spread further Antibodies: produced as a final defense against foreign substances Antitoxins: neutralizes the toxins given off by certain bacteria Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

How the Body Resists Diseases Fever Fights off infection or pathogens Few bacteria can survive beyond 102° F Inflammation Increase in the blood vessels to a specific area allowing antibodies to enter Erythema (redness) Heat Edema (swelling) Pain Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

How the Body Resists Diseases Immunity Ability to resist disease Natural immunity Acquired immunity Passive acquired immunity Active acquired immunity Natural acquired immunity Artificial acquired immunity Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

How the Body Resists Diseases Antigen substance injected into the body to stimulate specific antibodies Allergens Hypersensitive Anaphylactic shock Sometimes fatal Requires going through patient’s health history Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Normal Routes of Microorganism Exposure Direct contact: when a dental provider touches the lesion or blood of an infected person while working in the oral cavity Standard precautions Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Normal Routes of Microorganism Exposure Indirect contact: when dental provider or next patient obtains disease from contaminated instruments, supplies, or equipment Standard precautions Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.

Normal Routes of Microorganism Exposure Inhalation: takes place during the use of the high-speed handpiece, which creates an aerosol spray during patient care Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED.