CH32

Question 1

• sub devision of species

- progeny of a single cell

Answer 1

strain

Question 2

land but no establishment

Answer 2

resident

Question 3

effects of microbiota on the host

Answer 3

• germ free animals
• antimicrobial agents
• characteristics

Question 4

where do microbiota come from?

Answer 4

at birth, mostly from mother and air

Question 5

one benefits, the other neither harmed or benefitted

Answer 5

commensals

Question 6

-difficult to obtain

Answer 6

germ free animals

Question 7

characteristics of germ free animals

Answer 7

• underdeveloped immune system
  
  • lack antibodies to normal flora
  • vulnerable to opportunistic pathogens
• require vitamin K and more B vitamins

Question 8

how antimicrobial agents provide defense against pathogens

Answer 8

• competition for nutrients
• production of inhibitory compounds
• treating skin with hexachlorophene
• antibiotics- Clostridium difficile, Candidia albicans

Question 9

microbiota adherence

Answer 9

• specific receptors
  
  • Streptococcus salivarius (tongue), S. mutans (tooth enamel)
• glycocalyx, fimbriae
• washing, persistalis, desquamation

Question 10

prokaryotic antimicrobial substances

Answer 10

• anaerobic intestinal bacteria–> organic acids

- skin Staphylococci–>antibiotics

Question 11

label these parts of the body from most to least amount of microbiota: skin, mouth, stomach, eye, upper respiratory tract

Answer 11

mouth
skin
upper resp. tract
eye
stomach

Question 12

give two positives and negatives of microbiota on skin, mouth, stomach, eye, upper respiratory tract

Answer 12

skin
+lg surface area, O2 present, exposed, access, some nutrients
-washing, salt, temp, acidic, desquamation, competition

eye
+moisture, oxygen, moderate temp
-blinking, lysozyme, salt

upper respiratory tract
+moisture, nutrients, access, oxygen
-mucus (traps)

mouth
+moisture, lots of nutrients, variable O2 habitats (aerobic/anaerobic), warm (constant temp), pH neutral
-cleaning, lysozyme, competition, desquamation

stomach
+Lactobacillus and Candida
-numbers low (10/ml), hydrochloric acid, digestive enzymes

Question 13

• numbers low (10^3/ml)
• acidity and bile in duodenum and jejunum
• ileum

Answer 13

small intestine

Question 14

• numbers very high (23% of feces, 10^11/gram, 300+ species)

- mechanical movement, desquamation, mucus

Answer 14

large intestine

Question 15

anaerobic bacteria pre-dominate in large intestine

Answer 15

Gram + : Lactobacillus, Bifidobaterium

Gram - : Bacteroids

Question 16

facultative anaerobe bacteria pre-dominate in large intestine

Answer 16

Gram - : Escherichia

Question 17

why does microbiota composition vary in the large intestine?

Answer 17

• stress, starvation, antibiotics, diet

- probiotics- Lactobacillus

Question 18

bacteria pre-dominate in lower urethra in genitourinary tract

Answer 18

gram + : Staph. epidermis, Strep. faecalis

Question 19

how does glycogen production affect pH of vagina?

Answer 19

during years of ovarian activity

• estrogen stimulates the accumulation of glycogen in vaginal wall
• Lactobacillus ferment glycogen to acetic acid
• pH of vagina 4.4-4.6

Question 20

before puberty and after menopause, describe the adult female genital tract

Answer 20

pH slightly alkaline

colon mo’s predominate