what we don’t see can kill us!. also called microbes cannot be seen without a microscope may be...
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MICROORGANISMS
What we don’t see CAN kill us!
MICROORGANISMS Also called microbes Cannot be seen without a microscope May be non-pathogen or pathogen
depending on where it is in body
MICROORGANISMS Aerobes are a variety of bacteria that
require oxygen to grow. Anaerobes are bacteria that grow in
the absence of oxygen and are destroyed by oxygen.
Facultative anaerobes are organisms that can grow in either the presence or the absence of oxygen.
TYPES OF INFECTIONS Endogenous- originates inside the
body
Exogenous-originates outside the body
Nosocomial- infection obtained in a health care facility (Ex: MRSA)
Opportunistic- occurs when host resistance is down
BACTERIA Single cell 3 types: Cocci, Bacilli, Spirilla
BACTERIA-COCCI Round shaped
Micrococci- single cell
Diplococci-two celled
BACTERIA-COCCI Staphylococci-clustered
Streptococci- in chains
EXAMPLES OF COCCI DISEASES “Strep throat” Scarlet Fever Rheumatic fever “Flesh eating” disease Endocarditis Pneumonia MRSA Toxic Shock
BACTERIA-BACILLI Rod Shaped May have flagella that help the
bacteria to move Often produce spores Occur singly, in pairs or in chains Many produce poisons called toxins
SPORES Some bacteria change into the most
resistant form of life known called spores.
Bacteria remain alive in the spore form but are inactive.
They can survive extremes of heat and dryness and even the presence of disinfectants and radiation.
EXAMPLE OF BACILLUS Anthrax
EXAMPLES OF DISEASES FROM BACILLI Leprosy Tuberculosis Tetanus Botulism Diphteria Typhoid
BACTERIA-SPIRILLA Spiral shaped May be other “unusual” shapes Example: syphilis and cholera
BACTERIA-RICKETTSIAE The rickettsiae are short, nonmovable
rods that normally live in the intestinal tract of insects such as lice, fleas, ticks, and mosquitoes.
They are very small and require host cells to reproduce.
Diseases caused by rickettsiae include typhus and Rocky Mountain spotted fever.
These diseases are transmitted to humans by way of the bite of an infected insect.
CHLAMYDIA Smallest of all bacteria Originally thought to be a virus
GRAM STAINING Gram staining requires crystal violet
dye, iodine solution, alcohol solution, and a safranin dye be used in a certain order.
The bacteria that are stained by the dye are classified as Gram-positive. (They appear dark purple under the microscope.)
Gram negative bacteria will appear pink. Bacteria that are positive but stain as
negative are called Gram variable or there’s mixed colored staining.
GRAM POSITIVE
GRAM NEGATIVE
BACTERIA REVIEW
ALGAE Algae range from microscopic single-cell
organisms to larger multiple-cell organisms such as seaweed and kelp.
All algae contain chlorophyll, as well as pigments that cause them to appear yellow-green, brown, or red.
Algae are found in abundance in both freshwater and marine habitats.
Most algae do not produce human disease.
ALGAE
Red Tide
PROTOZOA One celled animal-like, may contain
flagella Often found in decayed materials,
animal feces, and contaminated water Cause malaria, dysentery (severe
diarrhea), and African sleeping sickness Not too common in the US
FUNGI Fungi are plants, such as mushrooms,
yeasts, and molds, that lack chlorophyll. Diseases include athlete’s foot,
vaginitis, “Jock itch”, and ringworm
HELMINTHS Multi-cellular worms or flukes Can be injected in food or obtained
when bitten by a mosquito Examples: pinworms, hookworms,
trichinella spiralis, tapeworms
VIRUS Viruses are smallest of all microbes
and only seen with electron microscope.
Viruses can live and multiply only inside an appropriate host cell.
A virus invades a host cell, copies itself, and then destroys the host cell so the viruses are released into the body.
Spread from human to human through body secretions
VIRUS- DISEASES HIV Common cold Influenza- Ex:H1N1 HPV- Human Papilloma Virus Polio Chickenpox Herpes
Zoster- shinglesSimplex Type 1- cold soresSimplex Type 2- genital herpes
VIRUS- DISEASES Hepatitis
HAV HBV HCV HDV HEV HGV
Vowels: Food and Fecal Borne Consonants: Blood Borne
PRIONS Infectious agent composed of primarily
protein that is misfolded Must reproduce inside a host cell Gets the other proteins to misfold as
well
PRIONS Prions are responsible for “mad cow”
disease and possibly Alzheimer disease. Prion-caused diseases have been found
in human beings and animals. Prions are highly resistant to heat,
chemical agents, and irradiation. There is no treatment or vaccine against
prion diseases, and the only preventive measure is not eating suspect food.
MICROBES TREE MAPMicroorganisms
Chlamydia
Algae
Protozoas Bacteria
Viruses
CocciMicrococciDiplococciStaphylococciStreptococci
Fungi PrionsHelminths
Bacilli
Rickettsiae
Spirilla