Bacterial Pathogenesis

Question 1

“sterile” sites of the body

Answer 1

places where we do not expect to find bacteria
-heart and circulatory system
-liver
-kidneys and bladder
-brain and CSF
-bones
-ovaries/testes
-glands
-middle and inner ear

Question 2

how does Staph aureus colonize the anterior nares

Answer 2

*uses MSCRAMMS (cell wall-attached surface proteins) and matrix proteins

Question 3

how does Staph aureus colonize the posterior nares

Answer 3

*interaction of the cell-wall linked wall TECHOIC ACID (WTA) with the scavenger receptor class F member 1 (SREC1)

Question 4

how does staph epidermidis compete with staph aureus for colonization in the nose

Answer 4

S. epidermidis secretes an extracellular serine protease (Esp) to degrade the matrix proteins and inhibit S. aureus colonization

Question 5

how does staph lugdunesis compete with staph aureus for colonization in the nose

Answer 5

S. lugdenensis secretes the antibiotic LUGDUNIN to prevent nasal colonization of S. aureus

Question 6

how does the microbiome change in the GI tract

Answer 6

density and diversity increases from the stomach to the large intestine

Question 7

benefits of normal flora

Answer 7

-protection from disease (competition, bacteriocins, lowering the pH)
-nutritional/medicinal/hormonal benefit (produce vitamins, metabolize bile)
-immune system development
-gut morphology and function development

Question 8

adverse effects of normal flora

Answer 8

-source of intestinal gas and body odor
-oral flora associated with cavities and periodontal disease
-can be the cause of opportunistic infections and disease

Question 9

opportunistic bacteria

Answer 9

can become pathogens, given the proper conditions (injury, immune compromise, etc)

Question 10

pathogens

Answer 10

bacteria that overtly cause disease