Lesson 6

Question 1

Blackleg in cattle
and sheep

Answer 1

C.chauvoei

Question 2

Malignant edema
in cattle, pigs and
sheep. Abomasitis
in sheep (braxy),
and occassionaly
in calves

Answer 2

C.septicum

Question 3

“Big head” in
young rams,
wound infection

Answer 3

C.novyi Type
A

Question 4

Gas gangrene,
necrotic enteritis,
and gangrenous
dermatitis in
chickens,
necrotizing
enterocolitis in
pigs

Answer 4

C.perfringens
Type A

Question 5

Myositis in cattle
sheep and
horses.Abomasitis
in lambs

Answer 5

C.sordelii

Question 6

Infectious necrotic
hepatitis (in
sheep) and
occasionally in
cattle

Answer 6

C.novyi Type
B

Question 7

Bacillary
haemoglobinuria
in cattle and
occassionally in
sheep.

Answer 7

C.haemotlyti
cum

Question 8

Lamb dysentery: caused by C. perfringens type B with up to 30% with high
mortality rates. β Toxin is extremely sensitive to trypsin digestion but in the
absence of proteolytic activity it retains its potency and produces disease. In
contrast, ε toxin, which is also produced by C. perfringens type B, requires
proteolysis via _____ for activation.

Answer 8

trypsin

Question 9

Factors which predispose to the development of enterotoxaemias associated with
_______________ in sheep.

Answer 9

Clostridium perfringens

Question 10

Low proteolytic activity in the neonatal intestine:

Answer 10

– Presence of trypsin inhibitors in colostrum
– Low level of pancreatic secretion

Question 11

Dietary influences in older animals:

Answer 11

– Abrupt change to a rich diet
– Gorging on energy-rich diet
– Intestinal hypomotility, a consequence of overeating

Question 12

caused by C. perfringens type D, occurs in sheep,
predisposing factor is overeating high grain diet. Ingestion of excessive quantities of food leads to ‘carry-over’ of partially digested food from the rumen
into the intestine leading to its high starch content in the partially digested food
which is a suitable substrate for rapid clostridial proliferation.

Answer 12

Pulpy kidney disease

Question 13

The disease,
which occurs in sheep at pasture, manifests as sudden death although some
animals may be found in terminal convulsions.

Answer 13

Struck

Question 14

caused by C. perfringens type C. Often,
entire litters are affected with mortality rates up to 80%. Infection is probably
acquired from the sow’s faeces. Poor husbandry may be a predisposing factor in
some outbreaks. Studies showed that binding of β toxin to vascular endothelial
cells occurs early in the course of disease and this may induce the vascular
necrosis which contributes to the pathological lesions observed

Answer 14

Haemorrhagic enteritis in piglets

Question 15

caused by C. perfringens type A and, less
frequently, by type C strains, primarily affects broilers up to 12 weeks of age. It is
an acute enterotoxaemia characterized by sudden onset and high mortality. A
newly identified toxin, NetB, is now considered to be an important virulence
factor of necrotic enteritis strains, and α toxin may be of lesser importance,
although the latter appears to be capable of inducing a protective immune
response.

Answer 15

Necrotic enteritis of chickens

Question 16

Diagnostic Procedures for C. perfringens infections

Answer 16

 Clinical signs and post-mortem findings
 Direct smears
 Bacterial culture
 PCR genotyping
 Toxin neutralization tests using mouse and guinea-pig inoculation
can definitively identify the toxins of C. perfringens present in the
intestinal contents of recently dead animals.
 ELISA to demonstrate toxin in vivo
 Treatment and control: hyperimmune serum, antibiotic therapy, and
vaccination. Avoid/prevent predisposing factors

Question 17

Infection with Clostridium difficile: reported in dogs ________ and
newborn foals _________. The organism produces two major
toxins, A and B, both of which belong to the family of large clostridial cytotoxins.
Toxin A is an enterotoxin and B is a potent cytotoxin.

Answer 17

(chronic diarrhea)
(hemorrhagic enterocolitis)

Question 18

The organism produces two major
toxins, _______, both of which belong to the family of large clostridial cytotoxins.

Answer 18

A and B

Question 19

is an enterotoxin

Answer 19

Toxin A

Question 20

is a potent cytotoxin

Answer 20

B

Question 21

implicated in enteritis in quails (quail
disease), chickens, turkeys, pheasants and grouse. Mortality rate: up to 100%
(quail), less than 10% (chickens).

Answer 21

Infection with Clostridium colinum

Question 22

a clostridial organism with atypical
coiled morphology, has been implicated in spontaneous and antibiotic-induced
enteritis in rabbits. Predisposing factors include oral administration of antibiotics
and low-fibre diets. A toxin elaborated by C. spiroforme is neutralized by antitoxin
to the ι toxin of C. perfringens type E as it is structurally similar to this toxin.

Answer 22

Infection with Clostridium spiroforme

Question 23

infection with Clostridium piliforme. This organism has not
been cultured on artificial media and grows only in tissue culture or in fertile eggs,
and formerly known as Bacillus piliformis, Infection results in severe hepatic
necrosis and is common in mice and other laboratory animals. Diagnosis is
based on the histological demonstration of the organisms in hepatocytes using
the Warthin-Starry silver impregnation technique.

Answer 23

Tyzzers Disease