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Startvac mechanism of action
- 1. START VAC ® INTRODUCTION SPC VACCINAL PLAN SLIME COLIFORMS
- 6. calving 0 13 35 45 97 -60 -45 -32 -10 0 52 130 dp calving ▼ ▼ ▼ ▼ ▼ ▼ ▼ OOI DOI S T A R T V A C S T A R T V A C S T A R T V A C Low risk Medium risk Very High risk High risk STARTVAC: Vaccination plan Immunity of STARTVAC Risk of S.aureus mastitis Risk of colibacilar mastitis Drying off Lactation
- 15. STARTVAC : Biofilm research and efficacy results Bacterins from strong biofilm-producing bacteria triggered the highest production of antibodies to PNAG and conferred the highest protection against infection and mastitis, compared with weak biofilm-producing bacteria and non-cellular inocula.
- 18. STARTVAC: Some general features of Escherichia coli E.coli J5 is a strain that lacks the enzyme Uridin Diphosphate Galactose 4-Epimerase, which is responsible for binding the somatic antigen (O-Antigen of polysaccharide) to the LPS molecule of the cell wall . The vaccine was developed with the concept of the exposure of the core antigen common to Gram-negative organisms in the mutant J5 strain (rough strain).
- 22. STARTVAC: Mechanism of protection Induction of antibodies against core epitopes of LPS common to gram-negative bacteria Induction of antibodies against SAAC components present in the biofilm matrix that produce staphylococcal bacteria during the initial phase of infection. Startvac Vaccination Antibodies anti-SAAC bind to the initial exopolysaccharide matrix production before the biofilm is established. Antibodies anti- E. coli J5 bind to the core antigens during the multiplication of invading bacterial cells, exposed just before the synthesis of LPS is completed. Intramammary infection (IMI) Phagocytosis of the opsonized bacterial cells by neutrophils Clearance of IMI due to S. aureus and CNS Clearance of IMI due to E. coli and coliforms
- 23. ANY QUESTIONS ? STARTVAC R&D TEAM
Hinweis der Redaktion
- Good afternoon everybody and thank you very much to come here. I would like to apologize for not speaking in Polish, but I will try to speak in English and Michal will translate the presentation for you. The purpose of my presentation is to introduce our new vaccine STARTVAC for the mastitis. To start with I will make an introduction about the mastitis and vaccination. Then I’ll explain you the characteristics of the STARTVAC vaccine. After that, I’ll talk about the field trials that we performed with STARTVAC, describing the design of the study and showing the efficacy results that we obtained. Finally , I’ll summarize my presentation with some conclusions. Please, do feel free to interrupt me if you have any questions.
- As we were convinced that a vaccine could be a help to control the mastitis, in the year 2000 we started the STARTVAC project for the development of a mastitis vaccine. The development of a vaccine is a long way that begins with the research on the (1)… Then it’s necessary to perform stability studies (2),…(3), (4) and (5). Finally, we decided to submit the STARTVAC dossier… (6). After the evaluation of the dossier, the European Comission .. (7).
- Let’s look now at the characteristics of the STARTVAC vaccine: STARTVAC is an inactivated vaccine with two antigenic components : E. coli J5. S. aureus , whose cells contain an extracel·lular component that we refer to as SAAC. I’ll explain the composition in more detail later. Additionally , STARTVAC vaccine have an oil-based adjuvant .
- STARTVAC should be administered to cows and heifers more than 22 months of age. The vaccination is indicated for herd immunisation of healthy cows and heifers,…
- The dose of the vaccine is 2 ml per animal and the method of administration is by … The recommended vaccination plan consist of a first vaccination at 45 days before the expected parturition date. A second vaccination 35 days ….And a booster vaccination at 62 days after the second vaccination.
- The vaccination plan was the indicated in the summary of product characteristics. The first dose of the vaccine was administered at 45 days before the expected parturation dat. Second immunization was 35 days thereafter (corresponding to 10 days before the expected parturition date).Finally, third vaccination was 62 days after the second vaccination (booster vaccination). This slide shows the relation between the vaccination plan and the risc of mastitis, before and after calving. You can see that the immunity conferred by the vaccination, between the Outset and the duration of immunity, includes the maximum risk for S. aureus mastitis and colibacilar mastitis.
- In this figure we can see a biofilm of S. aureus . Growing cells are surrounded by the extracellular matrix of polysaccharide and keep closer together inside the biofilm.
- Another characteristic of the S. aureus slime-producing strains is the mucous aspect of the colonies, as you can see in the figure. Next, let’s move on to explain in more detail the STARTVAC composition. First of all, I’ll begin by the definition of slime. In the last years is more frequently used the name of BIOFILM instead of SLIME , but both names are synonymous and refer to the extracellular matrix of S. aureus made up of polysaccharide . The chemical composition of slime is different than capsules. Both are polysaccharides, but chemically different. The production of this extracellular matrix it’s an important virulence factor that defines the ability of bacterial strains to colonize host tissues and biomaterials, participating in the intercellular adhesion among bacterial cells and subsequent development of a biofilm. This leads to chronic infections and bacterial resistance to phagocytosis. In staphylococcical bovine mastitis , bacteria adhere to the mammary gland epithelial cells and grow forming colonies surrounded by a large exopolysaccharide matrix, constituing a biofilm. Because of their aggregate size, biofilms are not susceptible to macrophage o neutrophil phagocytosis and become resistant to some antibiotics, promoting the chronicity of the disease. Poly- N -acetyl -1,6 glucosamine surface polysaccharide is a major constituent of the staphylococcal biofilm matrix.
- Next, let’s move on to explain in more detail the STARTVAC composition. First of all, I’ll begin by the definition of slime. In the last years is more frequently used the name of BIOFILM instead of SLIME , but both names are synonymous and refer to the extracellular matrix of S. aureus made up of polysaccharide . The chemical composition of slime is different than capsules. Both are polysaccharides, but chemically different. The production of this extracellular matrix it’s an important virulence factor that defines the ability of bacterial strains to colonize host tissues and biomaterials, participating in the intercellular adhesion among bacterial cells and subsequent development of a biofilm. This leads to chronic infections and bacterial resistance to phagocytosis. In staphylococcical bovine mastitis , bacteria adhere to the mammary gland epithelial cells and grow forming colonies surrounded by a large exopolysaccharide matrix, constituing a biofilm. Because of their aggregate size, biofilms are not susceptible to macrophage o neutrophil phagocytosis and become resistant to some antibiotics, promoting the chronicity of the disease. Poly- N -acetyl -1,6 glucosamine surface polysaccharide is a major constituent of the staphylococcal biofilm matrix.
- I said before that S. aureus inactivated cells in the SARTVAC vaccine contain SAAC. So, what is the relation between SAAC and slime or biofilm? SAAC is an extracellular component that we isolated from biofilm-producing S. aureus isolates . SAAC was chemically analysed and it showed to be constituted by 55 % polysaccharide and 45 % peptide. We refer to this component as “Slime Associated Antigenic Complex” because we saw that SAAC is only produced by S. aureus strains phenotypically characterised as slime-producing. On the other hand, we demonstrated that SAAC is involved in biofilm formation, because we found a correlation between SAAC production and the biofilm formation ability in vitro . Further analyses demonstrated that the SAAC-specific antigen is a polysaccharide. The polysaccharidic component of SAAC contains 6 % glucosamine and galactosamine. So, probably, the glucosamine we detect in SAAC could be deacetylated sugars from the PNAG (the main polysaccharide of the biofilm matrix).
- This figure shows the method to determine the slime-producing phenotype of S. aureus isolates.
- Another characteristic of the S. aureus slime-producing strains is the mucous aspect of the colonies, as you can see in the figure on the left. On the right side, you can see the result of a biofilm assay (o late adherence test). Basically, it consists in growing the strain in a microtiter plate. Then, wells are emptied and washed with PBS. Adhered cells are fixed and stained with safranin. Finally, the OD of the biofilm is measured with an ELISA microplate reader. In A, B and C rows, grew a biofilm producing strain. In D, E and F rows grew a non-producing strain. Rows G and H were non-inoculated negative controls.
- The levels of specific anti-SAAC and anti- E . coli J5 antibodies in serum of the STARTVAC group was…
- Well, I’ve told you about the S. aureus component of the STARTVAC. Now let’s look at the Escherichia coli J5 component. E. coli J5 is a natural mutant strain that laks the enzyme responsible for binding the Outer polysaccharide to the Core region of the LPS. So, the core antigen is exposed in the external membrane of this strain. The interesting thing of this strain is that the core region of LPS is highly conserved among a broad spectrum of Gram-negative bacteria.
- The levels of specific anti-SAAC and anti- E . coli J5 antibodies in serum of the STARTVAC group was…
- The results indicated that the serological response in milk…
- Furthermore, we observed a significant correlation between the…
- I’ll finish the characteristics of STARTVAC with the mechanisms of protection. The STARTVAC vaccination confers protection through the induction of antibodies against SAAC components present…. The vaccination also induce the production of antibodies against core epitopes of LPS …. When an intramammary infection occurs, antibodies anti-SAAC bind to the initial exopolysaccharide matrix production….; In the case of a coliform infection, antibodies anti- E. coli J5 bind to the core… Then, PMN phagocytose the opsonized bacterial cells, resulting in a clearance of the intramammary infection due to S. aureus an CNS, or E. coli and coliforms.