Dental Pathology and Microbiology Unit 1 Classifications of Microorganisms

Unit 1 Definition: Microbiology –Micro –Bio –Ology Oldest form of life Most are Beneficial Only a few are harmful

Why do we study Microbiology? The world we live in….. People live longer Diseases are now controlled Healthier Food Better conditions Medical Advances Environmental advances

Microbiology & Medicine Science MUST be ready to face the challenge Knowledge of transfer of microorganisms can reduce spread of disease Knowledge of immunity can reduce disease Knowledge of sterilization & disinfection procedures will reduce or prevent spread of disease Not all microorganisms are harmful, some are even helpful

Theory of Spontaneous Generation Mold on food Spoiled drinks & spoiled food Theory was = caused by devil or curse of God Seemed to be no physical cause Some scientists attempted to disprove theory “Catching” diseases spread by contact with humans and animals

Leeuwenhoek Dutch merchant & Amateur scientist Hobby of grinding lenses to observe microbes “Animalcules” = small moving objects Drew pictures and wrote volumes Early lenses led to early microscopes Took scrapings from teeth to observe appearance Referred to as Father of Microbiology

Pasteur Professor of chemistry in France Experimented with heating liquid Process of pasteurization Process used for wine, beer & Milk Food canning process Discovery labeled “Germ Theory of Disease” proved that airborne bacteria was the cause of some diseases

Golden Age of Microbiology Many new discoveries Communication was limited Scientists and doctors in all countries were working on theories Numerous causes of disease & death; patients died in hospitals; women died in childbirth Physicians wore street clothes in surgery

Holmes Physician in Boston Studied “child bed” fever in new mothers Suggested nurses and physicians wash hands

Semmelweis Hungarian doctor Explored use of antiseptics with washing Number of deaths were reduced Both Holmes & Semmelweis were working on same experiments in different countries

Lister English Surgeon Set out to prove that wound infection due to microbes Tried carbolic acid (PHENOL) Soaked surgical dressings & instruments & tables Asked staff to use phenol on hands after washing Established aseptic techniques

Koch German biologist & physican Proved ‘specific bacteria causes disease’ Developed rules –1. Organism must be present –2. Organism must be isolated –3. Organism must produce disease in another –4. Organism must be recovered

Miller American dentist & researcher Theory: connection between bacteria, carbohydrates & tooth disease BACTERIA + FOOD = Produce Acids Acids on teeth = cause decay (cavities)

Review Leeuwenhoek – Pasteur – Koch – Lister Holmes - Semmelweis - Miller -

Summer Fun

Normal Flora Resident microbial population of human body Microorganisms live (reside) in and on body *Always present

Activities of Microbes Bacteria in soil converted to usable nutrients Bacteria cultured to make vinegar, vitamins, antibiotics Bacteria or fungi used to pickle cucumbers; Produce cultured dairy: yogurt & sour cream Yeast makes bread dough & used in beer production

GROUPS OF MICROORGANISMS BACTERIA VIRUSES FUNGI – Yeasts & Molds PROTOZOA –Bacteria & viruses are concern in dental office –Some fungi can cause dental problems

BACTERIA Small cells Divide by binary fission SHAPES: –COCCI –BACILLI –SPiRILLA –VIBRIOS

Bacteria Grow in COLONIES Bacterial growth = increase in cell numbers Cells divide by BINARY FISSION Division of cells occurs every minutes Some bacteria have ability to grow Some bacteria do not survive

Growth Requirements of Bacteria Temperature Acidity Nutrients Oxygen Metabolism Water

Bacteria Culturing Bacteria – grow bacteria in laboratory Nutrient base called medium Preventing growth – changing requirements Bacteriostatic Bacteriocidal

Infections/Diseases from bacteria TUBERCULOSIS DIPHTHERIA PERTUSSIS TETANUS STREPTOCOCCAL Infections (caries) STAPHLOCOCCAL Infections

FUNGI: Yeasts & Molds Larger than bacteria Disease: Candidiasis (known as thrush) Found inside mouth Cannot be killed with antibiotics Usually cause problems after use of too much antibiotics

Candidiasis/Yeast/Thrush

Baby thrush

VIRUS Smaller than bacteria Have many shapes Cause disease by changing cells Cannot be killed with antibiotics Some antiviral drugs Best approach is immunization or Infection Control Procedures

Viral Diseases Measles, Mumps, Rubella Poliomyelitis Chicken Pox (Varicella) Common Cold Influenza Herpes Simplex Hepatitis

Shingles

VIRAL NO PPE??? Herpetic conjunctivitis- Herpes of eye Herpetic Whitlow- Herpes on hand

Protozoa Rickettsiae Live in bloodstream, mouth & digestive tract Contaminated drinking water Gum disease (Periodontal disease) Parasites – cannot live outside a host Diseases are Typhus & Rocky mountain fever

THE END Grandpuppies