Upper GI Micro

Question 1

name the two obligate anaerobe classes that are important for upper GI

Answer 1

clostridium

bacteriodes

Question 2

name the two facultative anaerobes that are important in the upper GI

Answer 2

E coli

candida

Question 3

what is a microaerophile? name the one that is important in the upper GI tract

Answer 3

helicobacter…require less O2 than atmoshpher

Question 4

what does it mean to be aerotolerant? name the important one for upper GI

Answer 4

do not need O2 but can be in presence of it

lactobacillus

Question 5

are anaerobes or aerobes more common in gut flora?

Answer 5

anaerobes by a ton

Question 6

what are the two predominant phyla in the gut?

Answer 6

bacteroidetes and firmicutes

Question 7

in GI infections…is it usually just anaerobe, just aerobe or a mix of both that cause the infection?

Answer 7

a mix of both

Question 8

supragingival plaque associated biofilms are formed by what class of organisms? are they aerobes or anaerobes?

Answer 8

gram pos…aerobes/erotolerant

Question 9

what is the common gram positive bacteria that causes supragingival plaques?

Answer 9

actinomyces

Question 10

subgingival plaque is associated with what class of bugs?

Answer 10

anaerobic gram negativ

Question 11

what bug is most common to cause subgingival plaque?

Answer 11

bacteroides

Question 12

is bacteroides gram neg or pos? what shape? anaerobe or aerobe?

Answer 12

gram neg
anaerobe
bacilli

Question 13

name the bacteroides specie that is involved with close to 80% of anaerobic GI infections

Answer 13

bacteroides fragilis

Question 14

can bacteroides attach to epithelial cells and enter by themselves? if not how do they infect?

Answer 14

no…they have to use an injury to gain access

Question 15

is actinomyces gram neg or pos? what shape? anaerobe or aerobe?

Answer 15

pos
anaerobe
bacilli

Question 16

why is actinomyces confused as a fungi sometimes?

Answer 16

because it has branching patterns

Question 17

what is actinomycosis? where does it occur on the body?

Answer 17

infection with actinomyces israeli…often in the jaw

Question 18

what does actinomycosis occur after usually?

Answer 18

dental procedures

Question 19

what does actinmycosis cause in the jaw that is a sign of it?

Answer 19

sulfur granules

Question 20

is clostridium gram neg or pos? what shape? anaerobe or aerobe?

Answer 20

pos
anaerobe
bacilli

Question 21

what are the clear ends on clostridium bacili?

Answer 21

endospores…for spore forming

Question 22

what bacteria ferments carbs, fatty and amino acids and makes a foul smell when doing so?

Answer 22

clostridium

Question 23

what clostridium species are associated with gas gangrene?

Answer 23

c perfringem and c septicum

Question 24

c perfringes and c septicum are associated with gas gangrene…which of these can spread in the blood and why can it do that?

Answer 24

c septicum can spread because it is slightly aerotolerant

Question 25

which clostridium species causes food poisoning?

Answer 25

c botulinum

Question 26

what is an endotoxin? what is an exotoxin? what is enterotoxin?

Answer 26

endotoxin is LPS from gram neg membrane exotoxin is secreted toxin from bacteria enterotoxin is secreted toxins that target enteric cells

Question 27

the toxin from c botulinum has what effect?

Answer 27

prevents stimulatory NTs from being released...paralysis

Question 28

the toxin from c tetani has what effect?

Answer 28

prevent release of inhibitory NTs...spasticity

Question 29

the toxin from c perfringens has what effect?

Answer 29

degrades tissue and cell membranes

Question 30

the toxin from c difficile has what effect?

Answer 30

cytoxic and inflammatory effects

Question 31

which organism often causes gas gangrene following surgery?

Answer 31

c perfringens

Question 32

which organism causes spontaneous gas gangrene?

Answer 32

c septicum

Question 33

how does spontaneous gas gangrene occur?

Answer 33

break in GI mucosa allows C septicum to enter bloodstream

Question 34

what is present in spontaneous gas gangrene and can be seen on surface of skin

Answer 34

gas...gas pockets on skin

Question 35

what two organisms often cause peritonitis?

Answer 35

E coli and B fragilis

Question 36

name the three antibiotics that are always effective against anaerobes

Answer 36

metronidazole carbapenems B lactams

Question 37

name the three antibiotics that are never effective against anaerobes

Answer 37

aminoglycosides bactrim aztreonam

Question 38

how do we treat esophagitis caused by candida?

Answer 38

fluconazole

Question 39

describe the steps in helicobacter pylori pathogenesis

Answer 39

flagella help it attach and be motile urease converts urea to ammonia and CO2 to raise local pH bacteria can replicate mucinases and other effectors can damage cell and induce inflammation

Question 40

what is the virulence factor that makes H pylori much more infectious?

Answer 40

cytotoxin associated genes

Question 41

where do cytotoxin associated genes reside in H pylori? can they be transmitted between strands?

Answer 41

on a pathogenecity island that can jump between strands

Question 42

what is the enzyme that is necessary for H pylori to live?

Answer 42

must have urease

Question 43

with ulcers from H pylori...what two drugs do you give?

Answer 43

antibiotic combo plus a PPI

Question 44

name the five most common H pylori test...which is most common?

Answer 44

``` serology stool antigen test urea breath test (most common) rapid urease test histology ```

Question 45

what is the shape of H pylori? where is it seen on histo?

Answer 45

curved bacili | attached to epithelial cells in the GI tract