Microbiology Fundamentals A Clinical Approach, 2nd ed. by Cowan Chapter 11.

Microbiology Fundamentals: A Clinical Approach, 2nd ed. by Cowan Chapter 11 The Human Host Correct Answer- The human body is in a state of dynamic equilibrium with microorganisms Healthy individuals have a peaceful coexistence with microbes and a lack of disease Occasionally the balance tips in favor of microbes and disease results Infectious Disease Correct 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 Correct Answer- Known as indigenous flora or normal flora Include an array of bacteria, fungi, protozoa, viruses, and arthropods Human Microbiome Project Correct 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 Correct 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 Correct 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