Clostridium tetani and botulism

Question 1

Clostridium tetanus source

Answer 1

bacterial spores in environment inoculated into damaged tissue

Question 2

Clostridium tetanus pathogenesis

Answer 2

trauma with inoculation of spores into tissue –> tissue must be devitalized so that the environment is anaerobic to support spore germination –> toxin disseminates through tissue and gains access to lymphatics and blood –> toxin reaches peripheral neuron binds to the receptor and is taken up by nerve –> toxin travels retrograde towards the spinal cord where it interferes with release of GABA

Question 3

Clostridium tetanus virulence factor

Answer 3

tetanus toxin (located on plasmid)

Question 4

Clostridium tetanus clinical signs in horses, ruminants, pigs – early stage

Answer 4

stiff gate, muscle tremors, and increased responsiveness to stimuli

Question 5

Clostridium tetanus clinical signs of descending tetanus (horses, ruminants, pigs)

Answer 5

retraction of third eyelid due to spasms
erectness of the ears
grinding teeth
stiffness of the tail
bloat

Question 6

Clostridium tetanus clinical signs – later signs (horse, ruminants, pigs)

Answer 6

lockjaw
tremors more constant and permanent – sawhorse stance
not able to stand
increase in body temp
death due to respiratory arrest

Question 7

Clostridium tetanus clinical sigs in carnivores

Answer 7

incubation period is longer
stiffness and tremors are frequently seen near the original wound
erect ears
retraction of third eyelid
tense jaw
sawhorse stance

Question 8

Clostridium tetanus diagnosis

Answer 8

based on clinical signs
gram stain shows gram-pos rods with terminal spores is suggestive
culture is rarely done

Question 9

Clostridium tetanus treatment

Answer 9

give antitoxin asap
give antibiotics to kill the bacteria
clean and decried wounds
sedation and muscle relaxants
nursing care

Question 10

Clostridium tetanus – what does antitoxin do?

Answer 10

it neutralizes unbound toxin, but does not affect toxin that has been absorbed by the nervous system

Question 11

Clostridium tetanus prognosis

Answer 11

10 to 50% survival
the earlier the initiation of treatment the better
takes weeks for nerves to regenerate

Question 12

Clostridium tetanus prevention

Answer 12

tetanus toxoid for horses, cattle, and sheep is available

horses should be vaccinated on regular basis

if horses survive infection, they need to be vaccinated since they don’t acquire immunity from infection

Question 13

Clostridium tetanus zoonotic?

Answer 13

no

Question 14

CLOSTRIDIUM BOTULINUM source

Answer 14

preformed toxin present in contaminated feed

Question 15

CLOSTRIDIUM BOTULINUM route

Answer 15

ingested toxin disseminates via the bloodstream to the neuromuscular junction where it blocks release of acetylcholine

Question 16

CLOSTRIDIUM BOTULINUM clinical signs

Answer 16

signs progress rapidly and are consistent with weakness and paralysis

head and neck: paralysis of tongue, drooling, sluggish pupillary light response

restlessness, incoordination, rear limb weakness

decr. muscle tone in tail, inability to stand

advanced: recumbency, labored breathing –> death

Question 17

CLOSTRIDIUM BOTULINUM diagnosis

Answer 17

presumptive based on history and clinical signs with rapid disease progression

Question 18

CLOSTRIDIUM BOTULINUM zoonotic?

Answer 18

no

Question 19

CLOSTRIDIUM BOTULINUM common sources

Answer 19

animal carcasses can serve as “toxin vectors”

preformed toxin in wet, rotten, spoiled food or animal carcass in bale of hay

invertebrates can serve as “toxin vectors” since they are resistant to the toxin