Download Microorganisms

Infection
Control
UNIT-F
Microorganisms or
Microbes
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Small living organisms
Not visible to the naked eye
Microscope must be used to see them
Found everywhere in the environment
Found on and in the human body
Many are part of normal flora of body
May be beneficial
Microorganisms
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This consist of any organism that can
be seen with the aid of a microscope
Also known as microbe
Microbe Classifications
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Bacteria
Protozoa
Fungi
Rickettsiae
Viruses
Pathogens
• Also known as germs
• Disease producing organism
• At times, non-pathogens can become
pathogenic when it is present in another
body system.
– Ex. E. Coli
Non-Pathogens
• Microorganisms that are part of the
normal flora and are beneficial in
maintaining certain body processes
Bacteria
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Simple, one-celled organisms that
multiply rapidly
Some are beneficial and some cause
disease
Classified by shape and arrangement
– Cocci- round or spherical in shape
– Bacilli- rod-shaped
– Spirilla- spiral or corkscrew in shape
Flesh Eating Bacteria
• Necrotising fasciitis (NF)
• NF is a bacterial infection that attacks the
soft tissue and the fascia which covers the
muscles. NF can occur from minor trama
but is usually related to surgery.
• The NF Bacteria is commonly called strep
type A.
Protozoa
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One-celled animals often found in
decayed materials and contaminated
water
May contain flagella, which allows
better movement
Some are pathogenic and cause
disease
– Ex. Malaria, amebic dysentery
trichomonas, and African sleeping disease
Fungi
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Simple, plantlike organisms that live on
dead organic matter.
Yeast and molds are two common forms
that can be pathogenic
Cause diseases
– Ex. Ring worm, athlete’s foot, thrush,
histopasmosis, and yeast vaginitis
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Cannot be killed by antibiotics
Fungus Cont.
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Antifungal medications are available
for pathogenic fungi
– Must be taken internally for long periods
of time and may cause liver damage
Athletes Foot
Penicillium
Ring
Worm
Rickettsiae
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Micro parasite that lives within an
organism
Commonly found in fleas, lice, ticks,
and mites
Transmitted to humans by the bites of
these insects
Rickettsiae
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Causes diseases
– Ex. Typhus fever and Rocky Mountain
spotted fever
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Antibiotics are effective against many
different rickettsiae
Viruses
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Lives on living cells
Smallest microorganisms
Visible only through electron
microscope.
Viruses
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Visible only through electron
microscope
Cannot reproduce unless they are
inside another living cell
Spread human to human by blood and
other body secretions
Viruses
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Difficult to kill because they are
resistant to many disinfectants and are
not affected by antibiotics
Cause diseases
Hepatitis B
Hepatitis B
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Also known as Serum hepatitis
Caused by HBV virus and is
transmitted by blood, serum, and
other body secretions
Affects the liver, leads to scarring or
destruction of liver cells
Life long infection
Cirrhosis of liver
Hepatitis C
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Caused by HCV virus
Transmitted by blood and blood
containing fluids
Referred to as ‘silent epidemic’
Sometimes don’t experience symptoms
for decades after infection
No vaccination, unlike Hep B
AIDS
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Acquired Immune Deficiency
Syndrome
Caused by the HIV virus (Human
immunodeficiency virus)
Suppresses immune system
Contracted by body fluids
Frequently contracts opportunistic
infections (i.e. cold turns into
pneumonia)
Endogenous
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Infection or disease originating within
the body
Include metabolic disorders,
congenital abnormalities, tumors, and
infections caused by microorganisms
Exogenous
• Infection or disease originating
outside of the body
• Include pathogenic organisms
that invade body, radiation,
chemical agents, trauma,
electric shock, and temperature
extremes
Aerobic
• Organisms that need oxygen to live.
Escherichia coli
Anaerobic
• Lives without oxygen.
Treated with hyperbaric
pressure
Noscomial
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Pertaining to or originating in a health
care facility such as a hospital
Usually transmitted from health care
worker to the patient
Often antibiotic-resistant
i.e. Staphylococcus, pseudomonas,
and enterococci
Discharge as soon as possible to avoid
Opportunistic
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Infections that occur when bodies
immune systems are weak
Do not usually occur within individuals
with good immune systems
– Ex. Kaposi’s sarcoma or neumocystis
carinii
Asepsis
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Being free from infection
Any object or area that may contain
pathogens is considered to be
contaminated
Aseptic techniques are directed toward
maintaining cleanliness and
eliminating or preventing
contamination
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Protozoa
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