Chapter 6: bacillus and clostridium

Question 1

bacillus is aerobic/anaerobic

Answer 1

aerobic

Question 2

clostridium is aerobic/anaerobic

Answer 2

anaerobic

Question 3

2 species of bacillus

Answer 3

bacillus anthracis

bacillus cereus

Question 4

4 species of clostridium

Answer 4

botulinum
tetani
perfringens
difficile

Question 5

bacillus anthracis is unique that it is the only bacterium with _____
-fnct?

Answer 5

a capsule composed of protein (poly-D-glutamic acid)

-prevents phagocytosis

Question 6

transmission of anthrax usually from

Answer 6

direct contact with infected animals or soil or when handling infected animal products, such as hides or wool

-no human to human

Question 7

where can anthrax spores germinate

Answer 7

skin (cutaneous anthrax)
inspired into lungs (respiratory anthrax)
ingested into the GI tract (GI anthrax)

Question 8

the exotoxin from bacillus anthracis causes what on localized tissue

Answer 8

necrosis

painless round black lesion with a rim of edema called a malignant pustule

Question 9

respiratory anthrax pathogology

Answer 9

spores taken up by macrophages in lungs and transported to hilar and mediastinal LNs

mediastinal hemorrhage occurs resulting in mediastinal widening

Question 10

GI anthrax occurs how often, and clinically

Answer 10

rare but often cuases death

exotoxin causes necrotic lesion within intestine

vomiting abdominal pain and bloody diarrhea

Question 11

antrax exotoxin is encoded on a plasmid called ___ which has 3 seperate proteins?

Answer 11

pXO1

edema factor (A subunit) increases cAMP which impairs neutrophil fnct and causes massive edema

protective antigen: promotes entry of EF into phagocytic cells

Lethal factor: zinc metalloprotease that inactivates protein kinase
-stimulates mactrohpage to release TNF-a and interleukin-1B

Question 12

second plasmid in anthrax ____ encodes 3 genes necessary for synthesis of ___

Answer 12

pXO2

poly-glutamyl capsule

Question 13

bacillus cereus clinically

Answer 13

food poisoning releaseing enterotoxin
nausea, vomiting, diarrhea

-antibiotics won’t help

Question 14

bacillus cereus enterotoxins

Answer 14

heat labile toxin
-nausea, abdrominal pain and diarrhea lasts 12-24 hours

heat stable toxin: nausea and vomiting, limited diarrhea

Question 15

clostridium botulinum produces

Answer 15

lethal neurotoxin, blocks release of Ach from presynaptic nerve terminals in ANS = flaccid muscle paralysis

Question 16

adult botulism

-how does one get it and symptoms

Answer 16

smoked fish or home canned veggies
potent neurotoxin ingested
pts afebrile
initially develop bilateral cranial nerve palsies: double vision and dysphagia
then muscle weakness which leads to repiratory paralysis and death
-pts need ventilator

Question 17

infant botulism

how do babies get it and symptoms

Answer 17

fresh honey contaminated with spores
-spores colonize GI tract
infant constipted for 2-3 days then dysphagia and muscle weakness
“floppy” babies must be hospitalized and given supportive therapy

Question 18

wound botulism presentation

Answer 18

longer incubation period

pts more likely to have a fever and elevated white count

Question 19

clostridium tetani spores are often found where

Answer 19

soil and animal feces

Question 20

what is the exotoxin released by clostridium tetani

Answer 20

tetanospasmin
-inhibits GABA and glycine
taken up at NMJ and transported to CNS

Question 21

pts with tetanus present with

Answer 21

severe muscle spasms especially in the muscles of the jaw
-trismus or lockjaw
risus sardonicus (spasm of facial muscles)
-high mortality once this occurs

Question 22

clostridium perfringens

Answer 22

in anerobic conditions it matures and produces gas

Question 23

3 classes of infection with clostridium perfringens

Answer 23

cellulitis/wound infection: palpation reveals moist, spongy, crackling consistency called crepitus

clostridial myonecrosis: trauma into muscles secretes exotoxins that destory adjacent muscle, gas formation pockets in the muscles and subcutaneous tissue
-as enzymes degrade the muscles, a thin, blackfish fluid exudes from skin

diarrheal illness: watery diarrhea
-more severe type can lead to hemorrhagic necrosis of the jejunum

Question 24

C diff toxins

Answer 24

toxin A causes diarrhea

toxin B is cytotoxic to colonic cells

Question 25

c diff infection presentation

Answer 25

when pt develops watery diarrhea while on an antibiotic or within a month of being on an antibiotic