Lecture 12 Normal Flora

Question 1

bacteria that permanently colonize host

Answer 1

normal microbiota

Question 2

bacteria that may be present for days, weeks, or month

Answer 2

transient microbiota

Question 3

Gram + bacteria are often found ____

Answer 3

on the skin

Question 4

Gram - bacteria are often found ___

Answer 4

in the gut

Question 5

the relationship between the normal microbiota and the host

Answer 5

symbiosis

Question 6

commensalism

Answer 6

one organism benefits and the other is unaffected

ex. staph epidermidis

Question 7

mutualism

Answer 7

both organisms benefit

ex. e coli in large intestine

Question 8

parasitism

Answer 8

one organism benefits at the expense of the other

ex. H1N1 in host cell

Question 9

superoorganisms

Answer 9

blend of host and microbial traits resulting when a metabolic processes of host are integrated into the microbe

Question 10

opportunistic pathogens

Answer 10

members of normal microbiota that produce disease under certain circumstance

Question 11

characteristics of skin for microbiota

Answer 11

mechanical strong barrier

inhospitable environment (slightly acidic pH, high [NaCl], low in moisture)

inhibitory substances

Question 12

what type of microbes live on the skin?

Answer 12

gram positive, halophiles

staphylococci (s. epidermidis)
micrococci (m. luteus)
diphtheroids

Question 13

sebum

Answer 13

fluid secreted by oil glands that accumulates and provides hospitable environment for p.acnes

Question 14

where on the eye are bacteria found?

Answer 14

small numbers on conjunctiva of eye

mostly s. epidermidis

Question 15

bacteria on the external ear are similar to flora found where?

Answer 15

the skin as well as fungi

Question 16

what causes dental caries

Answer 16

oral bacteria

esp. s. mutans and lactobacillus

Question 17

how to mouth bacteria survive removal?

Answer 17

adherence to gums and teeth

cause formation of dental plaque, caries, gingivitis, and periodontal disease

Question 18

pharynx and trachea contain what type of bacteria?

Answer 18

gram positive

esp. staph (S. epi), micrococci (m. lutes), diphtheroids, strep. (alpha- and beta- hemolytic)

Question 19

nasopharynx contain (high/low) pathogenic bacteria

Answer 19

low

Question 20

Which part of the respiratory tract is sterile?

Answer 20

lower respiratory

due to ciliary escalator, alveolar macrophages, and lysozyme in mucus

Question 21

what causes movement of microbes in lower respiratory tract?

Answer 21

ciliary escalator

continuous stream of mucous generated by ciliated epithelial cells

Question 22

stomach host defense mechanism

Answer 22

acidic conditions

only survive if passed thru quickly or if ingested in food particles

Question 23

duodenum has (many/few) organisms

Answer 23

few

Question 24

pH becomes more alkaline in this part of the small intestine.

Answer 24

ileum

flora present is similar ot colon

Question 25

where is the largest microbial population in the body?

Answer 25

large intestine

Question 26

how are microbes eliminated from the colon?

Answer 26

peristalsis desquamation movement of mucus high reproductive rate so readily replaced

Question 27

microbes of the colon are (aerobic/anaerobic)

Answer 27

anaerobic

Question 28

bacteria found in large intestine (11)

Answer 28

``` e. coli bacteroides fusobacterium lactobacillus enterococcus bifidobacterium enterobacter citrobacter proteus klebisella candida ```

Question 29

where is there a state of flux in microbial [populations?

Answer 29

female genital tract caused by menstrual cycle

Question 30

kidneys, ureter, and bladder microbes

Answer 30

free of microbes distal urethra = few microbes

Question 31

lactobacilli bacteria

Answer 31

predominate in vagina grow on glycogen secretions produce H2O2

Question 32

principle microbiota of skin (8)

Answer 32

``` Propionibacterium Staphylococcus Corynebacterium Micrococcus Acinetobacter Brevibacteria Candida Malassezia ```

Question 33

Conjuctivia principle microbiota (7)

Answer 33

``` staph epidermidis s. aureus diphtheroids propionibacterium corynebacterium streptococci micrococcus ```

Question 34

nose microbiota

Answer 34

s. aureus s. epidermidis diptheroid

Question 35

throat microbiota

Answer 35

s. epidermidis s. aureus diphtheroids streptococcus pnumoniae haemophilus neisseria

Question 36

what keeps bacteria out of skin?

Answer 36

lots of contact but hard colony to survive sweat secretion and oil glands --> antimicrobial low moisture very salty keratin is good, strong barrier

Question 37

eye environment

Answer 37

similar to skin but also have mucous membrane secretions and tears (lysozyme) and blinking to eliminate microbes

Question 38

mouth environment

Answer 38

warm, moist, presence of food (lots of bacteria here) biting, chewing, moving tongue, salvia dislodge

Question 39

large intestine environment

Answer 39

largest microbiota -- available nutrients and moisture mucus and shedding + epithelial enzymes keep bacteria from colonizing

Question 40

Reproductive microbial environment

Answer 40

acid tolerant (vagina) mucus and shedding of lining microbes from colonizing in uterus pH of urine and urea are antimicrobial cilia and mucus expel microbes from the cervix