MICROBIOLOGY FUNDAMENTALS A
CLINICAL APPROACH EXAM SCRIPT FULL
QUESTIONS AND CORRECT ANSWERS
GUARANTEED TO PASS
●● Infectious Disease
Answer: Disruption of a tissue or organism caused by microbes or their
products
Contact progresses to infection and ends in disease
Not all contacts lead to colonization
Not all colonization leads to infection
Not all infections lead to disease
Contamination without colonization and colonization without disease are
the rules
●● Normal (resident) biota
Answer: Known as indigenous flora or normal flora
Include an array of bacteria, fungi, protozoa, viruses, and arthropods
,●● Human Microbiome Project
Answer: Uses metagenomics
Identifies genetic sequences to determine which microbes are inside and
on humans, even though they can't be cultured in the lab
Determines what the normal biota play in human health and disease
●● Acquiring Resident Biota
Answer: The human body has an endless variety of microbial niches
Most areas of the body in contact with the outside environment harbor
resident microorganisms
Internal organs and tissue and their fluids are microbe-free
Majority of microbes that come in contact with the human body are
destroyed by the immune system before they are able to colonize
The microbes that remain have developed a complex relationship with
the human host in which they can survive and not be harmful to the host
,●● Sites that harbor a known normal biota
Answer: Skin
Mucous membranes
Respiratory tract
GI tract
Outer opening of urethra
External genitalia
Vagina
External ear canal
External eye (lids, conjunctiva)
Lungs
Bladder & urine
Breast milk
Amniotic fluid & fetus
Brain
Bloodstream
●● Microbial antagonism
Answer: Normal biota are unlikely to be displaced by incoming
microbes
Limited number of attachment sites
, Chemical or physiological environment created by resident biota is
hostile to other microbes
Normal biota is beneficial (ex: produce vitamin K), or at worst,
commensal to the host in good health with a functioning immune system
●● Factors that weaken host defenses/increase susceptibility to infection
Answer: Old age and extreme youth (infancy, prematurity)
Genetic defects in immunity and acquired defects in immunity (AIDS)
Surgery and organ transplants
Underlying disease (cancer, liver malfunction, diabetes)
Chemotherapy/immunosuppressive drugs
Physical and mental stress
Pregnancy
Other infections
CLINICAL APPROACH EXAM SCRIPT FULL
QUESTIONS AND CORRECT ANSWERS
GUARANTEED TO PASS
●● Infectious Disease
Answer: Disruption of a tissue or organism caused by microbes or their
products
Contact progresses to infection and ends in disease
Not all contacts lead to colonization
Not all colonization leads to infection
Not all infections lead to disease
Contamination without colonization and colonization without disease are
the rules
●● Normal (resident) biota
Answer: Known as indigenous flora or normal flora
Include an array of bacteria, fungi, protozoa, viruses, and arthropods
,●● Human Microbiome Project
Answer: Uses metagenomics
Identifies genetic sequences to determine which microbes are inside and
on humans, even though they can't be cultured in the lab
Determines what the normal biota play in human health and disease
●● Acquiring Resident Biota
Answer: The human body has an endless variety of microbial niches
Most areas of the body in contact with the outside environment harbor
resident microorganisms
Internal organs and tissue and their fluids are microbe-free
Majority of microbes that come in contact with the human body are
destroyed by the immune system before they are able to colonize
The microbes that remain have developed a complex relationship with
the human host in which they can survive and not be harmful to the host
,●● Sites that harbor a known normal biota
Answer: Skin
Mucous membranes
Respiratory tract
GI tract
Outer opening of urethra
External genitalia
Vagina
External ear canal
External eye (lids, conjunctiva)
Lungs
Bladder & urine
Breast milk
Amniotic fluid & fetus
Brain
Bloodstream
●● Microbial antagonism
Answer: Normal biota are unlikely to be displaced by incoming
microbes
Limited number of attachment sites
, Chemical or physiological environment created by resident biota is
hostile to other microbes
Normal biota is beneficial (ex: produce vitamin K), or at worst,
commensal to the host in good health with a functioning immune system
●● Factors that weaken host defenses/increase susceptibility to infection
Answer: Old age and extreme youth (infancy, prematurity)
Genetic defects in immunity and acquired defects in immunity (AIDS)
Surgery and organ transplants
Underlying disease (cancer, liver malfunction, diabetes)
Chemotherapy/immunosuppressive drugs
Physical and mental stress
Pregnancy
Other infections
