CHAPTER 13: INTRO

Question 1

microbe human interactions: how do humans and microorganisms interact?

Answer 1

with development of biofilms

Question 2

what is normal flora?

Answer 2

normal mutual or commensal relationship with the body

Question 3

what is an infection?

Answer 3

when pathogenic microbes penetrate the host and enter tissue to MULTIPLY

Question 4

what is a pathogen?

Answer 4

an infectious agent

Question 5

what is an infectious disease?

Answer 5

an infection that causes damage or disruption to tissue and organs

Question 6

what areas of the body can come in contact with external microbes?

Answer 6

• skin
• mucuous membranes
• upper resp tract
• GI tract
• urethra opening
• external genitalia
• vagina
• ear canal
• external eye (lash, follicle, lids)

Question 7

internal organs contact w microbes

Answer 7

they are microbe free

Question 8

transients

Answer 8

microbes in the body for SHORT amount of time

Question 9

residents

Answer 9

microbes that become established

Question 10

microbial antagonism?

Answer 10

bacterial flora prevents overgrowth of harmful microbes in the body

Question 11

endogenous infections

Answer 11

normal flora is introduced to a site that was previously sterile

• infection caused by a pathogen that was present in their body prior to infection

Question 12

uterus and infants:
- sterility
- flora

Answer 12

• sterile until just before birth
• breaking fetal membrane exposes infant, feeding/handling infant will introduce what will develop into their normal flora

Question 13

how do you change transients? residents?

Answer 13

transients: hygiene

residents: stable and predictable, they are less influenced by hygiene

Question 14

variations in flora of gi tract reasons?

Answer 14

exposure to environment and variations in the flora distribution is due to changes in conditions: temp, pH, oxygen, anatomy etc….

Question 15

where is most of the flora? where is it most diverse?

Answer 15

large intestine, rectum, and mouth

most diverse in the mouth

Question 16

what kind of environment does the intestine favor?
what is usually here in small numbers?

Answer 16

anaerobic bacteria

• coliforms present

Question 17

what metabolic waste does bacteria make

Answer 17

vit B12, pyridoxine, riboflavin, thiamine, acetic acid, butyric acid, propionic acid

host can use these

Question 18

what contributes to odor?

Answer 18

released by intestinal bacteria: gasses, amine, skatole

Question 19

first organism to colonize the resp tract

Answer 19

streptococci

Question 20

how does S.aureus enter the body

Answer 20

nasal, vestibule (ear), and anterior nasopharynx

Question 21

how does Neisseria enter the body

Answer 21

mucous membrane of nasopharynx

Question 22

how does Haemophilus enter the body

Answer 22

tonsils and lower pharynx

Question 23

unfavorable enviros for permanent residents

Answer 23

• bronchi
• lungs
• lower resp tract

Question 24

where do males harbor bacteria in urethra

Answer 24

anterior urethra

Question 25

vaginal changes that influence normal flora

Answer 25

- pH, estrogen, glycogen

Question 26

how does flora fight against infection - other influences?

Answer 26

creates enviros to protect against infection by enhancing host defenses other influences on flora: antibiotics, dietary changes, disease

Question 27

why do probiotics not work sometimes

Answer 27

microbiome is complex between diff ppl, contains well adapted bacteria probiotics only have few species of bacteria, these strains are well adapted for industrial growth rather than gut growth