Microbiology

Microbiology

Study of very small life forms Can’t see them with

the eye Most are not

harmful Used for

Vitamins Antibiotics Some food

products Yogurts cheese etc.

Some are harmful Pathogens

Disease causing micro-organisms

Includes Bacteria, Viruses Protozoa Rickettsiae, Yeasts molds

Important people in Microbiology

Anton Van Leeuwenhoek Ground lenses

(glass) to magnify things

Saw moving micro-organisms

In plaque Wrote about

findings. Father of

Microbiology.

Important people in Microbiology

Louis Pasteur Experimented w/

fermentation Proved bacteria

causes disease. Proved heat killed

bacteria and spores Work led to canned

food. “Pasteurization”

Heat product to kill germs. (Milk, beer)

Important people in Microbiology

Robert Koch Proved specific

bacteria causes specific diseases.

Etiologic agent Aka causitive

agent Developed Koch’s

Postulates Steps to prove

that bacteria caused disease.

Gram Stain

Helps ID the group of bacteria Developed by Dr.

Christian Gram Cells place on a

slide Dye added Rinse w/ iodine Dry Rinse w/ water and

acetone alcohol Cell is observed.

Gram Positive Cell will appear:

Dark purple

Gram Negative Cell will appear:

To lose color Appear clear Appear “pink”

not purple

Gram Stain

Bacteria

Tiny Single celled Living organism

No chlorophyll molecule that

absorbs sunlight Divide every 20

min. Warm Dark Moist

Killed w/ antibiotics

Spores

Spores Bacteria that has

Sporulated or is Sporulating

Coats itself in Layers of protein Ensures survival

Resists Drying / Heat Boiling Most chemicals radiation

Used in autoclave “biological

monitor”

Bacteria and Oxygen

Aerobic Needs O2 to grow

and live Most bacteria are

aerobic Certain

Neisseria Pseudomonas

aeruginosa Staphylococcus,

or staph

Anaerobic Die with O2

Can only live without O2

Gram-negative anaerobes

Porphyromonas (periodontitis)

Gram-positive anaerobes

Peptostreptococcus (oral infections)

Bacteria and Oxygen

Facultative anaerobic bacteria Grow and live

With or Without O2 They cause

Oral and dental infections. Bacteremia

bacteria in the blood stream Endocarditis.

Inflammation inside layer of the heart.

Bacteria Morphology

Cocci Round Circular Spherical

streptococcus

Bacilli Rod Straight

Lactobacilli

Bacteria Morphology

Spirilla Spiral Spring Corkscrew

Helicobacter pylori

Vibrous C shaped Curved (comma)

Vibrio cholerae

Bacteria arrangements

Single Cell

Pairs

Clusters

Chains

Colonies (lg. clusters)

Bacterial diseases

Tuberculosis Diphtheria Pertussis Tetanus Strep throat Pneumonia Rheumatic fever

Staph infection Gangrene Toxic shock Venereal diseases

Aka (STD’s) Chlamydia

Anthrax

Protozoa

Single celled animal life Aka ameoba

Live in fluids: Blood Saliva Intestines Polluted water

Pools ponds

Causes; Dysentery

Severe diarrhea Malaria

Severe ‘flu’ Sleeping sickness Periodontal disease

Found in: Plaque Perio pockets

Yeasts and molds

Includes: Bread yeast Mushrooms Bread molds

Form of plant life No chlorophyll Cannot be killed w/

antibiotics.Used for Bacteria /

protozoa

Causes Candidiasis

Aka thrush Fungal infection of:

Mouth Vaginal area

Treatment Anti-fungal drugs

Virus

Smallest microorganism

Needs a host cell to reproduce.

Most are anaerobic Die w/ exposure to

air. Not killed w/

antibiotics Polio Virus

Examples of viral infections

Measles Rubella

(German measles)

Mumps Infection of the Parotid salivary

glands

Polio Chicken pox Cold Influenza (flu) Hepititis HIV AIDS

Routes of exposure

Direct contact. Sneezing into an open mouth. Touching open sores.

Indirect contact. Sneeze onto hand, touch door handle,

next person touches handle. Inhalation

Aspirating / breathing in.

How the body resists diseases

1st line of defense. Intact skin Sneezing Coughing Vomiting Diarrhea

2nd line of defense. Circulatory

system Wbc’s delivered

to area of infection.

Inflammation 4 signs of

inflammation Erythema

(redness) Edema

(swelling) Heat Pain

How the body resists diseases

3rd line of defense Antibodies

Produce immunity from specific pathogens. Disease causing microorganism

Antigen Pathogens that cause body to produce

antibodies. Allergen

An antigen that causes an over-reaction Can cause anaphylactic shock.

Immunity

A person/bodies ability to resist a pathogen or disease.

Two kinds Natural

Born w/ it. Acquired

Have to get it. Naturally Artificially

Acquired immunity

Passive Antibodies from

another person are injected into you.

Immediate Short term

6 weeks Breast milk

provides some passive immunity to baby

Active Natural acquired

Person gets a disease, body produces antibodies, should not get disease again.

Artificial acquired Immunization

Antigen is injected Antibodies are

produced

Conclusion

Understanding the disease process and how it affects the human body is very important.

You are the “expert”! Don’t ever diagnose! When in doubt…ask questions. Any questions?????????