L21: Clostridia

Question 1

what shape spores does clostridia have ?

Answer 1

oval bulging spores

Question 2

which clostridia spp. has a drum stick appearance ?

Answer 2

C. tetni

Question 3

what is the habitat of C.tetni ?

Answer 3

soil

Question 4

what is the usual portal of entry for C.tetni?

Answer 4

would site

Question 5

what is the tetonus toxin and how does it function ?

Answer 5

exotoxin that is carried to the CNS , bind to ganglioside receptors and blocks release of inhibitory mediators at spinal synapses

Question 6

C. tetni neurotoxin causing contraction of muscle :

Answer 6

tetanospasmin

Question 7

tetanus usually begins with :

Answer 7

lock-jaw / trismus

Question 8

neonatal tetanus stems from :

Answer 8

mother never being immunized +infection of unhealed umbilical stump ( cutting of umbilical cord with unsanitary instruments )

Question 9

which treatment of tetanus can neutralize the bacterias toxin ?

Answer 9

hyper immune human globulin

Question 10

how often should the tetanus toxoid booster be given?

Answer 10

every 10 years

Question 11

C. perfringens spore:

Answer 11

subterminal spores

Question 12

what disease can be caused by C. perfringens ?

Answer 12

gas gangrene

food poisoning

Question 13

what is the habitat of C. perfringens ?

Answer 13

soil , vegetative cells are normal flora of colon and vagina

Question 14

gas gangrene is associated with

Answer 14

war wounds / automobile accidents

septic abortions

Question 15

what is gas gangrene ?

Answer 15

germination of spores under anaerobic conditions

anaerobic metabolism causes degenerative enzymes to produce gas in tissues

Question 16

what toxin of C. perfringens is responsible for gas gangrene ?

Answer 16

alphatoxin (lecithinase)

Question 17

food poisoning caused by C. perfringens is due to :

Answer 17

enterotoxin similar to that of S. aureus

Question 18

what agar can detect alphatoxin lecithinase of C. perfingens ?>

Answer 18

egg yolk agar (naglers test )

Question 19

what is the habitat of C. botulinum ?

Answer 19

soil , contaminated vegetables and meats

Question 20

what are some high risk food concerning C. botulinum ?

Answer 20

alkaline vegetables likes green peas , peppers , mushrooms , and smoked fish

Question 21

how is C.botulinum toxin absorbed ? how does it affect the body ?

Answer 21

absorbed from gut and carried via blood to peripheral nerve supply where protease cleaves proteins involved in acetylcholine release causing flacid paralysis

heat liable toxin

Question 22

what are the 2 clinical forms of C. botulinum infection ?

Answer 22

wound botulinum : spores contaminate a wound , germinate and produce toxin at site

infact botulism : organism grows in gut and produces toxin there

Question 23

swollen cans should be discarded because they may contain which organism ?

Answer 23

C,botulinum : clostridial proteolytic enzyme can form gasses which then swells the cans

Question 24

which clostridium spp. is found in the colon ?

Answer 24

C. difficlle

Question 25

which infection causes pseudomembranous colitis ? on the sigmoid colon

Answer 25

C. difficile , also causes antibiotic associated diarrhea and antibiotic associated colitis

Question 26

route of transmission for C. difficile :

Answer 26

feco-oral route

Question 27

exotoxins of C.difficile :

Answer 27

exotoxin A and B
B: causes death of enteroytes