Micro Chapter 14
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Micro Chapter 14
Be able to describe the different kinds of symbiosis and what they result in.
Mutualism- both members benefit
Commensalism- one benefits, other is unharmed.
Parasitism- one benefits, other is harmed.
Be able to explain the results of contamination, infection and disease.
Contamination- coming into contact with disease causing organism; sometimes
results in infection
Infection- organism is successfully living and reproducing in the host; sometimes
may result in disease.
Disease- a change in the hosts health as a result of infection.
Compare and contrast pathogenicity and virulence.
Pathogenicity- the ability of an organism to cause disease.
Virulence- the relative ability of a pathogen to infect a host and cause disease.
can help break down structural molecules, hide them and
provide protection, inhibit isolation.
harm or trigger the host's immune system in such a way to cause harm.
keep them from being phagocytized.
four virulence factors
is always part of the population of organisms found on the inner
and outer surfaces of the body and is commensal or mutalistic.
always part of the population and can be parasitic if the normal microbiota is
removed or the hosts immune system is compromised.
What causes an organism to become transient?
Their environment undergoes a change. Immune suppression. Introduced to a new
location that it is not normally found.
Explain how we acquire normal flora.
Acquired at birth when the newborn passes through the birth canal. Baby then picks
up normal flora from everything person and surface if comes in contact with.
What are the major sites of entry and exit?
Skin, Mucous membranes, placenta, parenteral routes.
Know and be able to compare and contrast the different ways kinds of diseases
are classified (infectious, noninfectious, by idiopathy, communicable and
Infectious- can be transmitted to others
noninfectious- cannot be transmitted to others
Idiopathy- spontaneous disease; unknown cause.
Communicable- diseases that are transmitted either directly or directly from an
Noncommunicable- diseases that develop outside the host or from normal
microbiota and are not passed from one host to another.
What is etiology?
The study of the causes of disease.
What is the germ theory and how is it related to Koch’s postulates?
Germ theory- diseases are caused by infections by microscopic organism.
Koch developed Kock's postulates to figure out who did what in the germ theory.
Know examples of extracellular enzymes and how they work
Hyaluronidase and Collagenase- break down structural molecules allowing them to
invade deeper tissues.
Coagulase- catalyzes the formation of clots which provides protection and hiding
Kinases- aid invasion by digesting blood clots that would normally isolate them in
toxins that are secreted and they primarily destroy host cells or interfere
with host metabolism.
toxins that remain in the organism. usually only effect the host when
they are released when the organism is destroyed.
cells in general
What is the difference between a sign, a syndrome and a symptom?
Sign- something that can be measured such as fever or rash
Syndrome- name for the signs and symptoms that present or are seen with a
particular disease or condition.
Symptom- how you feel such as pain or dizziness.
Be able to explain the difference in the 3 different types of reservoir.
Animal, Human, Nonliving
What is a fomite?
How are diseases transmitted?
Contact- direct contact with portal of exit, indirect contact, droplet transmission
Vehicle- air, water, food
Vector- animals. Biological vector- transfer and act as a host. Mechanical- only
How do you know someone is a “carrier”?
Symptoms, not always
Understand what is happening in each of the five stages of a disease and how you
would recognize them.
Incubation period- ends with appearance of signs and symptoms
Prodromal period- signs and symptoms just starting and are very mild
Illness- host feels the worst, immune system isn't "cranked up" yet.
Decline- host is conquering the pathogen, signs and symptoms decline
Convalescence- repairing damage and restoring to normal state.
Be able to discuss the 3 types of epidemiology studies, what they are used for and
when you would use them.
Descriptive- collection of data about a disease. Ex. tracing the source of the bubonic
plague in London in 1854
Analytical- looks at descriptions of disease to determine probable cause, mode of
transmission, possibly prevention. Done after outbreak as occurred.
Experimental- coming up with a hypthoesis and testing it.
3 factors influencing nosocomial infections
Increased exposure to pathogens
Potential hosts with weakened immune system
Ease of transmission provided by the health care environment.
3 Universal Precautions instituted by the CDC.
Wearing gloves and gowns
Who would you report the occurrence of a contagious disease to?
Local disease control organization
What is the difference in endemic, epidemic, sporadic and pandemic?
Endemic- occurrence is almost always within the population
Sporadic- only shows up occasionally
Epidemic- has made an increase in occurrence.
Pandemic- occurs simultaneously in more than one continent.
What is the most effective way to reduce nosocomial infections?
Know the 3 roles of Public Health Agencies.
Work to limit transmission of disease, conduct inspections, run tests for disease on
food and water sources.
What does WHO stand for and what does it do?
World Health Organization- inform and educate the public and various