10 Microbiology

2 Important People in Microbiology Anton Van Leeuwenhoek –Magnifying glass Saw microorganisms from teeth for the first time Ferdinand Julius Cohn –Classified bacteria as plants –Divided bacteria into four groups

3 Important People in Microbiology Louis Pasteur –Process of fermentation Proved bacteria causes disease

4 Important People in Microbiology Robert Koch –Koch postulated that organisms must be: Present in all cases of the disease Isolated in pure culture Capable of producing the disease in another person or animal Recovered again in pure culture

5 Important People in Microbiology Richard Julius Petri –Petri dish –Further developed technique for dispensing the bacteria onto the medium

6 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

7 Bacteria Need for oxygen –Aerobic bacteria must have oxygen to grow and live –Anaerobic bacteria are destroyed in the presence of oxygen –Facultative anaerobic bacteria grow with or without oxygen present

8 Diseases Caused by Bacteria Tuberculosis –Bacteria found in 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

9 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”)

10 Diseases Caused by Bacteria Strep throat –Very common –Sore throat, fever, general malaise –Streptococcus mutans Species of the same bacteria Implicated in dental caries and endocarditis

11 Diseases Caused by Bacteria Staphylococcal infections –Bacteria groups grow in clusters Antibiotics are the first line of treatments

12 Diseases Caused by Bacteria Anthrax –Humans can get disease through cuts in skin or eating diseased meat –Powder form Symptoms within 1 to 6 days Fever, weakness, dry hacking cough Prevention by vaccination or antibiotic treatment before symptoms

13 Diseases Caused by Bacteria Chlamydiae –Microorganisms somewhere between bacteria and viruses (small in size) Genital, eye, and lymph node infections Most common sexually transmitted disease in the United States Antibiotics used as treatment

14 Protozoa Just below visibility of the naked eye Always dividing and changing shape Flagella –Many have this long, threadlike appendage

15 Diseases Caused by Protozoa Amebic dysentery –Severe diarrhea Abscesses may develop in liver –Prevalent in countries where drinking water is contaminated and poor hygiene conditions prevail

16 Diseases Caused by Protozoa Periodontal disease (protozoa and bacteria) –Both 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

17 Diseases Caused by Protozoa Malaria –Symptoms during the first two weeks Fever and soreness at point of entry

18 Rickettsiae Parasites cannot live outside a host –Lice, fleas, ticks, and mites transmit disease to humans

19 Diseases Caused by Rickettsiae Head lice –Common among children in schools –Transmitted easily through direct contact –Eggs reproduce in hair shafts –Treatment Medicated shampoo and cleaning bedding, brushes, and clothing with very hot water

20 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

21 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

22 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

23 Diseases Caused by Yeasts and Molds Tinea –Appearance named according to site infected Tinea pedis (Athlete’s foot) Tinea corporis (Ringworm) Tinea unguium –White patches on toe or fingernail

24 Diseases Caused by Yeasts and Molds Prion (pree-on) –Proteinaceous infectious particles made of only protein Mad Cow Disease Creutzfeldt-Jacob Disease

25 Viruses Must live inside hosts Antibiotics cannot kill the virus Treatment is primarily to ease the symptoms for the patient’s comfort

26 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

27 Diseases Caused by Viruses Rubella or German measles –Rash on face 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

28 Diseases Caused by Viruses Poliomyelitis or polio –Attacks the central nervous system Severe paralysis is a possibility

29 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 is better than as an adult

30 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

31 Diseases Caused by Viruses Common cold and influenza –Flu vaccines are successful in 60 percent of patients –Flu is contagious from 12 to 72 hours after symptoms appear –Flu is spread through airborne droplets

32 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

33 Treatment of HSV I –Depends on its type, site, and severity –Dental teams may reschedule patient if sores are apparent Primarily for patient comfort, although some offices may have policies –Many treatments readily available Diseases of Major Concern to the Dental Assistant

34 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

35 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

36 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

37 Diseases of Major Concern to the Dental Assistant Viral hepatitis –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

38 How the Body Resists Diseases Infection –Pyogenic membrane Dam built around infected area preventing it to spread further –Antibodies Produced as a final defense against foreign substances

39 How the Body Resists Diseases Infection –Antitoxins Neutralizes the toxins given off by certain bacteria

40 How the Body Resists Diseases Fever –Fights off infection or pathogens Few bacteria can survive beyond 102° F

41 How the Body Resists Diseases Inflammation –Increase in blood vessels to a specific area allowing antibodies to enter Erythema (redness) Heat Edema (swelling) Pain

42 How the Body Resists Diseases Immunity –Ability to resist disease Natural Acquired Passive acquired Active acquired Natural acquired Artificial acquired

43 How the Body Resists Diseases Antigen substance injected into body to stimulate specific antibodies –Allergens –Hypersensitive –Anaphylactic shock Sometimes fatal Requires going through patient’s health history

44 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

45 Normal Routes of Microorganism Exposure Indirect contact –When dental provider or next patient obtains disease from contaminated instruments, supplies, or equipment –Standard precautions

46 Normal Routes of Microorganism Exposure Inhalation –Takes place during use of high-speed handpiece Creates an aerosol spray during patient care