basic microbiology

5/24/2018 Basic Microbiology

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Basic Microbiology

Chapter 3, Section 4Health Technologies IIMr. Kestner


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Basic Microbiology

The science that studies living organisms

that cannot be seen with the naked eye

A microscope is only way to view the millionsof tiny creatures living in our environment

They are found almost everywhere on planet

They are on our skin, in the air we breathe,on every surface we touch, and even inside

our bodies


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Microbiology

Are also referred to as microbes, or more

commonly, germs, especially to laypeople

(layperson: one not in the fieldin this case,

those without a science background)

Usually do not notice microorganisms until

they cause physical illness

We often forget microbes play beneficial role

in human health; benefits are greater than

problems created by microbes


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Problems v. Benefits

PROBLEMS

Various infections in human

beings and animals are causedby microorganisms

BENEFITS

They prevent exposure to other

harmful microorganisms

They support production of

bread, cheese, yogurt, beer, and

several other foods and

beverages

They contribute to health of soil

for farming

They aid in purifying waste water


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Nature of Microorganisms

Small number of microorganisms, called

pathogens, cause disease

Most are harmless, called non-pathogens

Some may be pathogenic in one situation, and not

in others (e.g., Escherichia coli (E. coli)bacterium),

certain varieties cause diarrhea

Normally in intestinal tract, breaks down waste, aids insynthesis of Vit K (helps control bleeding)

If E. colimoves to another part of body, major

problems result


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Factors influencing growth

Whether microorganism is harmful or

beneficial, it needs favorable conditions to

grow

Conditions vary with type of microbe

Temperature

pH (acidity versus alkalinity)

Food

Moisture

Oxygen (for certain bacteria)


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Factors influencing growth

Conditions vary all over human body

All microbes need food and moisture to survive

Most pathogens prefer warm, dark environment

Only few tolerate acidic environment (low pH)

Some live only in presence of O2: aerobic

Others grow in absence of O2: anaerobic

Some consume only living matter tissues

Others prefer dead matter tissues

Altering living environment is a way to destroy


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Methods of Destruction

Three common practices used to prevent

growth and spread of microorganisms:

Antiseptics

Disinfection

Sterilization


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Antiseptics

Solutions applied directly to skin

Prevent or slow down growth

Alcohol and betadine are often used

Not useful against all microorganisms


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Disinfection

Uses strong chemicals such as bleach solution and

zephirin to kill many pathogens

Used mainly on objects and not on the skin

because they may cause skin irritation and trauma

Disinfectants and antiseptics have limited effectsagainst viruses and spores

Spores are cells produced by bacteria either to

reproduce or to be resistant to a harsh environment


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Sterilization

Best way to kill all microbes and their spores

Autoclave is used to sterilize medical instruments Uses steam under pressure

Other methods include use of chemicals, radiation,and gas

Not all microbes require sterilization to becomenontoxic or non-pathogenic, many microbes can beeliminated by disinfecting procedures


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Types of Microorganisms

Microorganisms are tiny living plants or

animals

The five major types are: Bacteria

Fungi

Protozoa

Rickettsiae (parasites)

Viruses


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Bacteria

Most familiar of microbes that infect humans

One-celled plants classified by shape and

arrangement Diseases such as strep throat and

pneumonia are caused by form of bacteria

Can be categorized according to howarranged; arrangement is way to identify

exact species


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Bacteria

Some are:

Roundcocci

Streptococci

chains

Staphlococciin

groups or clusters

Diplococciin

pairs

Micrococci

Strep Staph

http://www.life.umd.edu/classroom/bsci424/PathogenDescriptions/StreptococcusImages.htm
http://www.life.umd.edu/classroom/bsci424/PathogenDescriptions/StreptococcusImages.htmhttp://www.life.umd.edu/classroom/bsci424/PathogenDescriptions/StreptococcusImages.htm


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Bacteria

Some are:

Rod-shapedbacilli

In pairs, single or in chains

Flagellatail

Salmonella

http://www.bmb.leeds.ac.uk/mbiology/ug/ugteach/icu8/uti/gnb.html
http://www.bmb.leeds.ac.uk/mbiology/ug/ugteach/icu8/uti/gnb.htmlhttp://www.bmb.leeds.ac.uk/mbiology/ug/ugteach/icu8/uti/gnb.html


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Bacteria

Some are:

Spiral, or corkscrew-

shapedspirilla

Vibrios Spirochetes

http://www.biology.iastate.edu/Courses/201L/CellTypes/ http://www.biology.iastate.edu/Courses/201L/CellTypes/

Which picture is yogurt?


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Fungi

Also contribute to illness

Is a plantlike organism that lives on dead

matter Responsible for conditions such as

ringworm, athletes foot, and yeast infections

http://www.swedishmedical.org/PERT/images/thrush.jpg

Say ahhh
http://www.swedishmedical.org/PERT/images/thrush.jpghttp://www.swedishmedical.org/PERT/images/thrush.jpg


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Protozoa

Tiny animals

found in

contaminated

water supplies Microorganisms

that cause

diseases such as

malaria,trichomoniasis,

and amebic

dysenteryhttp://www.mblwhoilibrary.org/exhibits/leuckart/virtual_tour/images/protoza_large13.jpg
http://www.mblwhoilibrary.org/exhibits/leuckart/virtual_tour/images/protoza_large13.jpghttp://www.mblwhoilibrary.org/exhibits/leuckart/virtual_tour/images/protoza_large13.jpg


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Rickettsiae

Parasites that must live inside cells of otherliving organisms

One type of bacteria

Diseases caused by these microbes aretransmitted to humans by the animalparasite inhabits, such as fleas, lice, and

ticks Humans bitten by infected insect may

contract diseases such as Rocky Mountainspotted fever, Lyme disease, or Typhus


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Viruses

Smallest of all microorganisms

Only be seen through electron microscope

Difficult to destroy

Grow and reproduce only inside other living cells Humans are infected by contact with other living

beings

Spread by contact with blood and body fluids

Diseases associated with viruses are commoncold, chickenpox, herpes, hepatitis B, andHIV/AIDS

Health care workers are at great risk of beingexposed to blood and body fluidsPPE!


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Video Clips

Various microscopic clips from

Microbiologybytes.com

13 Minute video clip about 1918 flu from

PBS.org
http://www.microbiologybytes.com/video/motility.htmlhttp://www.microbiologybytes.com/video/motility.htmlhttp://www.pbs.org/wgbh/nova/sciencenow/3318/02.htmlhttp://www.pbs.org/wgbh/nova/sciencenow/3318/02.htmlhttp://www.pbs.org/wgbh/nova/sciencenow/3318/02.htmlhttp://www.pbs.org/wgbh/nova/sciencenow/3318/02.htmlhttp://www.microbiologybytes.com/video/motility.htmlhttp://www.microbiologybytes.com/video/motility.html

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