Normal Flora

Question 1

importance of normal flora

Answer 1

protective

pathogenic

nutritional- vitamin K

overgrowth can cause fat malabsorption and vitamin b12 deficiency

Question 2

aerobes or facultative bacteria in mouth

Answer 2

viridans streptococci
neisseria
diphtheroids
s. epidermidis

Question 3

viridans streptococci

Answer 3

gram pos cocci

most common cause of subacute bacterial endocarditis

thrive on sugar

Question 4

nessieria species

Answer 4

gram neg diplococci

neisseria meningitidis inhabits nasopharynx and causes meningitis

Question 5

diphtheroids

Answer 5

gram pos rods

most common contaminants in blood cultures

Question 6

s. epidermidis

Answer 6

gram pos cocci

another common contaminant of blood culture

coagulase neg

Question 7

role of normal aerobic flora in disease

Answer 7

1 if eliminated by antibiotics, can be colonized by pathogens

2 some individuals have pathogens in their mouths

3 can be colonized by e coli or kleb in hospitalized

Question 8

anerobes in the oral cavity and drug sensitivities

Answer 8

fusobacterium- penicillin sensitive
prevotella- penicillin sensitive
peptostreptococcus- peniccilin sensitive
actinomyces

do not extend into trachea

cause peridontal infections and aspiration pneumonia

Question 9

normal stomach flora

Answer 9

none- acid

Question 10

normal upper small intestine

Answer 10

generally sterile, but can cause disease if stasis occurs

Question 11

normal terminal ileum flora

Answer 11

gram neg enterobacteria- e coli, enterobacter

anaerobes- bacteroides fragilis

Question 12

normal bacteria in large intestine/ feces

Answer 12

bacteroides- gram neg anaerobic rods

form ammonia, acid, and gas

bacteroides fragilis- resistant to penicillin, causes intraabdominal infections

treated w/ clindamycin, cefoitin, or metronidazole

bifidobacterium- gram pos rods- non pathogenic

lactobacilli- gram pos rods- produce lactic acid and keep pH low

clostridium

enterococcus

Question 13

establishment of normal intestinal flora

Answer 13

sterile at birth

colinzed w/in hours and looks normal by the time infant is bottle fed

Question 14

maintenance of intestinal flora

Answer 14

oxygen level and pH

administration of antibiotics

presence of nutrition provided by other bacteria

Question 15

metabolic activities of normal flora

Answer 15

bile acid deconjugation- abnormal growth in upper intestine will impair fat absorption

provides ammonia to blood

conversion of bile pigments (bilirubin to urobilin and stercobilin)

ferment undigested carbs and drop pH

bacteroidetes found in lean individuals and firmicutes in obese individuals

Question 16

normal flora of skin

Answer 16

staphylococcus epidermis

staphylococcus aureus- opportunistic pathogen

diphtheroids- grap pos

proprionibacterium

Question 17

normal upper respiratory tract flora

Answer 17

nose- S aureus

throat- viridan streptococci, neisseria, s. epidermis

anerobes- bacteroides, fuscobacterium, clostridium, peptostreptococcus

Question 18

normal flora of genitourinary tract

Answer 18

lactobacillus- acidic pH

e coli

enterbacter

strep B