Salmonella and Campylobacter

Question 1

Explain the importance of Salmonella and Campylobacter contamination in the human food chain.

Answer 1

Salmonella
- Infection largely by S.enteritidis in poultry meat and eggs

Campylobacter
- Infection of broiler chickens (rapid colonisation of entire flock within 24-48 hr - airborne spread)

Question 2

Identify the risk factors of flock infection with these pathogens

Answer 2

• Other chicken houses
• domestic animals
• vehicles
• wildlife
• equipment
• visitors
• other farms

Question 3

Compare and contrast the strategies currently used to control Salmonella and Campylobacter in poultry

Answer 3

Salmonella
Fall in human salmonellosis in the UK coincided with vaccination (live attenuated) + biosecurity of egg laying flocks (rodents, dust and faeces, people and equipment, vehicles) + Chemotherapy (antibiotics dependent on susceptibility testing)

Campylobacter
Strict biosecurity can be successful
But can it be maintained?
Organic / free range flocks almost impossible.
These measures include:
dedicated PPE for each house
improved facilities and protocols for hand hygiene
step-over barriers between a ‘clean’ and ‘dirty’ part of the ante-room
better drainage.
Irridation - eliminates campylobacter
Freezing of positive carcasses

Question 4

Describe the microscopic appearance of salmonella

Answer 4

Gram negative non sporylating rods

Question 5

Define dysbiosis

Answer 5

Dysbiosis: microflora imbalance may lead to reinfection and prolonged excretion of Salmonella

Question 6

Describe the British Lion Quality Code of Practise

Answer 6

Launched in 1998
Compulsory vaccination of pullets against SE.
Independent auditing of farms.
Traceability back to farm/flock.
Best before date stamped on eggs.
On-farm hygiene controls.
85% of UK eggs produced under BLQ scheme.
Does not guarantee eggs are Salmonella free

Question 7

Describe the microscopic appearance of campylobacter

Answer 7

Gram –ve, motile, spiral-shaped rod.