Host-microbe interactions

Question 1

Host-Microbe interaction:

Host damage is the result of both microorganism and _______ factors.

_________ is the relative capacity of microbe to damage host.

Does the establishment of infection imply the presence of disease?

Answer 1

Question 2

What are the three types of pathogens?

Answer 2

•Frank/primary pathogen—microorganism that is capable of causing human disease in an otherwise healthy host. Possess inherent abilities to cause host damage.

•Opportunistic pathogen—microorganisms that is capable of causing human disease if given the right “opportunity”

•Commensal—microorganisms that induces no damage or clinically inapparent damage.

Question 3

Flora (microbiome)

Answer 3

• What distinguishes a pathogen from commensal is whether or not during its lifestyle it causes damage.
• Although commensals and pathogens may share similar characteristics or traits that allow successful host interactions, frequently the pathogens go a little step further, and on many occasions, these additional traits are what lead to damage/disease.

Question 4

Entry/exit host

Answer 4

Question 5

Transmission

Answer 5

Colonization

Colonization is not a passive process. Organisms have evolved and inherited specific factors that allow them to actively establish a relationship/unique niche within the host. This is only a small list of traits that enhance the ability of organisms to establish colonization within the host.

Question 6

After colonization microorganisms can either ______ or _______.

Answer 6

Invasion/Spread—Some pathogens are capable of crossing mucosal membranes and other tissue barriers to enter normally sterile sites and more susceptible tissue. They can breach epithelial surfaces by going through or between cells to gain access to the blood or lymphatic systems or even to intracellular niches.

Question 7

Staphilococcus aureus pathogenic components

Answer 7

Question 8

What are the phases of host defense?

Answer 8

•Non-induced innate immunity/barriers: skin, lysozyme in tears, respiratory mucociliary clearance, epithelial cell sloughing, acidity of stomach, antimicrobial peptides.

•Induced innate immunity: Pathogens are made up of molecules that are unique and can be recognized

–>Acute inflammation

•Acquired immune defenses

•Type of host response is differentially stimulated depending on the pathogen.

Question 9

Evolution refers to___.

Answer 9

• New opportunities for host-microbe interactions due to human progress (e.g., Super-absorbent tampons—TSS, water cooling towers—Legionella)
• New opportunities due to microbial evolution (e.g., Bird flu, carbapenemase-producing Enterobacteriaceae)

Question 10

Showing that microbes cause specific diseases: