Francesco prandini

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Francesco prandini

  1. 1. Francesco Prandini – DVM MERIAL Avian Technical Manager EMEA Protection against Salmonella infection using vaccines Baromfiágazat annual Seminar 2013 Budapest, October 1st 2013
  2. 2. Introduction • Salmonella spp is one of the major causes of food-borne illness in humans • High prevalence of Salmonella in poultry • Chicken and chicken products are the most frequent sources of zoonoses World Poultry - Dec 29, 2011
  3. 3. Salmonella • Motile non-host-specific serovars: >2000 serovars nearly ubiquitous in wild and domestic animals • Very common but seldom cause clinical disease • More often, asymptomatic persistent colonization of the intestinal tract • “Paratyphoid” infections of poultry and zoonoses
  4. 4. Zoonoses cases in humans in 2011
  5. 5. Salmonella epidemiology • S.Enteritidis (SE) and S.Typhimurium (ST) are the serovars most frequently associated with salmonellosis in humans through the food chain • Commonly asymptomatic colonization of chickens in the intestinal tract • Egg shell contamination • SE can infect eggs internally
  6. 6. Distribution of food vehicles in outbreaks caused by S.Enteritidis in the EU, 2011
  7. 7. Distribution of the 10 most common Salmonella serovars in humans in the EU, 2010-2011
  8. 8. Salmonella in human cases, eggs and laying hens and the number of Salmonella outbreaks caused by eggs within the EU, 2007-2011
  9. 9. Breeders Gallus gallus Laying hens Gallus gallus Broilers Turkeys S.Enteritidis S.Enteritidis S.Enteritidis S.Enteritidis S.Typhimurium S.Typhimurium S.Typhimurium S.Typhimurium S.Infantis *All salmonella serovars with public health significanceS.Hadar S.Virchow Serovars* with established targets for reduction of prevalence in the EU
  10. 10. Salmonella control in Chickens • Control of biological reservoirs: – Breeders – Replacement flocks – Rodents – Red mites • Rigorous biosecurity measures • Slaughtering of positive Breeders/Layers flocks • Competitive exclusion and Probiotic effects • Vaccination • Comprehensive programs of risk reduction
  11. 11. Salmonella VACCINATION Specific protection against S. serovars Both Live and Killed vaccines have been associated with significant protection An important component of SE-ST plans of risk reduction in Layers and Breeders Farm-tailored vaccination strategies
  12. 12. Salmonella VACCINES Live attenuated vaccines: • Mass application • Mainly local immune response Inactivated vaccines: • Individual s.c./i.m. injection • Mainly humoral immune response Vaccination programs: • Live • Inactivated • Live + Inactivated
  13. 13. Live VACCINE  A live attenuated vaccine against S. Enteritidis  Adenine - Histidine double auxotrophic strain  Drinking water administration  2 or 3 doses tailored programs  Early and long-lasting protection  Easy and rapid field strains differentiation Gallivac Se strain Field strain
  14. 14. Challenge trial with GALLIVACChallenge trial with GALLIVAC®® SeSe Oral Vaccination @ 2,16 & 114 days of age, and challenge with 5 billion pathogenic SE bacteria into the crop of each bird at 78 weeks of age. Number of bacteria per gram of tissue 7 days after challenge. 0 10.000.000 20.000.000 30.000.000 40.000.000 Caecum @ 79 weeks Un vaccinated Gallivac Se 0 50 100 150 200 250 300 Liver at 79 weeks
  15. 15. Inactivated VACCINE  A bivalent inactivated vaccine against S.Enteritidis and S.Typhimurium for pullets  Innovative manufacturing method to preserve antigenicity  0.3 ml emulsion dose s.c. or i.m.  2 doses program: from 6 wks & 16 wks  Rapid and lasting protection Classical processControlled nutrient fermentation
  16. 16. Blood sampling Comparison of inactivated vaccines Gallimune® Se+St W10 W16 W16 W10 W30 Se+St Al hydroxide W16W10 Control group unvaccinated W30 W30 G 1 G 2 G 3
  17. 17. Antibody titres at 30 weeks
  18. 18. Gallimune® Se+St W10 Competitor vaccine W16 W16 W12 Challenge W27 W27 +4 days +4 days Ovary sampling 60 pullets SE PT4 oral challenge Challenge 1: ovary contamination
  19. 19. Challenge trial with Gallimune® Se + St Results of isolation of S. Enteritidis PT4 in the ovaries of birds 4 days post oral challenge at 27 weeks of age. -90%
  20. 20. • Groups of 60 pullets: – Vaccinated at 10 & 16 weeks of age with Gallimune Se + St - 0.3 ml – 12 & 16 weeks with reference vaccine - 0.5 ml – Controls – 29 weeks of age: oral challenge with ST – 31 weeks of age: oral challenge with SE – Caecal droppings collected 4 days post challenge Challenge trial with Gallimune® Se + St
  21. 21. Gallimune ® Se+St W10 W16 W16 W12 W29 W29 +4 days Challenge 2: fecal shedding Other vaccine • 29 weeks  ST challenge oral route • 31 weeks  SE challenge oral route +4 days Gallimune® Se+St Reference vaccine Challenge Faeces sampling
  22. 22. Challenge 2: fecal shedding
  23. 23. Challenge 2: fecal shedding
  24. 24. SINGLE or COMBO vaccination programs PROTOCOL Age of chicks Group 1 Group 2 Group 3 Day 1 Gallivac Se drinking water Gallivac Se drinking water Controls Day 42 Gallivac Se drinking water Gallivac Se drinking water --- Week12 Gallivac Se in drinking water --- --- Week 4 Gallimune Se+St im breast injection --- Week 52 challenge with SE or ST challenge with SE or ST challenge with SE or ST
  25. 25. Challenge study PROTOCOL • Lohmann Brown Commercial layers • Oral challenge with 109 CFU of SE or ST • Birds sacrificed 7 days after challenge • Enumeration of SE and ST cells per g. of caecal content
  26. 26. 52 weeks - SE challenge
  27. 27. 52 weeks - ST challenge
  28. 28. Conclusions  Salmonella requires comprehensive control plans  Vaccination is an important component  Live and inactivated vaccines has specific features  Combined vaccination programs consolidate advantages from both  Farm-tailored vaccination strategies are required
  29. 29. Thanks for your attention

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