Salmonella and Campylobacter

Question 1

What are the key facts of salmonella?

Answer 1

• Gram neg
• Non sporulating rod
• Most are motile
• Contaminated poultry= major source of infection

Question 2

What are the 2 main subtypes of salmonella?

Answer 2

Enteriditis and typhimurium

Question 3

Describe how enteriditis is transmitted

Answer 3

-Can infect eggs and at many different stages

Question 4

Which serotype of salmonella do we vaccinate against?

Answer 4

S. Enteriditis

Question 5

Which factors increase the risk of a salmonella outbreak?

Answer 5

• Rodents (they amplify salmonella numbers because certain serotypes can amplify in their GI systems)
• Red mites (can carry salmonella)
• Poor hygiene (faeces attract rodents- some poultry barns all drops into big piles underneath)
• People, equipment, vehicles, feed can all be a source

Question 6

How do you eradicate S.E?

Answer 6

• Very difficult
• Almost impossible in old fashioned poultry houses that can’t be thoroughly cleaned
• Vaccination
• Acid treated feed
• Sanitised water
• Air disinfection

Question 7

Describe the S.E vaccinating protocol

Answer 7

• Live, attenuated vaccines
• Stimulate humoral AND CMI
• 3 doses (1 day, 2-6 weeks, prior to onset of lay)
• Some strains affected less by the vaccine.

Question 8

What does Dysbiosis mean?

Answer 8

-Imbalance: may lead to reinfection and prolonged excretion of Salmonella

Question 9

What is the British Lion Quality Code of Practice?

Answer 9

• Launched in 1998
• Compulsory vaccination of pullets against SE
• Independant auditing on farms
• Traceability (to farm/ flock)
• BBD stamped on eggs
• On farm hygiene controls
• DOES NOT guarantee Salmonella free

Question 10

What is the Zoonoses Order 1989?

Answer 10

Isolation of Salmonella from specificed animals, carcasses, products, feeding stuffs should be reported to DEFRA/ APHA

Question 11

What is entailed in the control of Salmonella in Poultry Order 2007?

Answer 11

• Sampling requirements for Salmonella in breeding/ laying flocks
• EU reg 2160/ 2003
• Restrictions imposed on fllocks/ produce which test positive for certain serotypes

Question 12

What are the key facts about Campylobacter?

Answer 12

-Gram neg
-Spiral shaped rod
-Commensal
- Most common species:
C. jejuni, C.coli and C. lari
-Mainly horizontal transmission

Question 13

Describe campylobacter infection of broiler chickens

Answer 13

• Rarely occurs before 2 weeks of age (lag phase)
• Low infective dose
• Rapid colonisation of entire flock (24-48hrs)
• Airborne spread/ coprophagy

Question 14

What are the potential environmental sources of Campylobacter?

Answer 14

• Vehicles
• Wildlife
• Visitors

Question 15

How can transport/ processing increase levels of campylobacter?

Answer 15

• Catching crew use same heavily contaminated equipment between farms
• Transport crates contaminated
• Water trays crates cleaned in infected

Question 16

Why don’t we have same control methods for Campylobacter that we do for Salmonella?

Answer 16

• Methods used to control Salmonella don’t work for Campylobacter
  e. g. no vaccine

Question 17

How is campylobacter controlled in retail?

Answer 17

• Irradiation kills campy
• Freezing carcasses helps
• Modified atmosphere packaging
• FSA survey chicken in supermarkets