Serology and fecal shedding studies, plus case studies from the field, have demonstrated that vaccines developed with SRP technology are highly efficacious against Salmonella bacteria infections on dairy operations. Case studies on commercial dairies have further proven the effectiveness against salmonellosis and fecal shedding of Salmonella bacteria. Researchers believe that the use of Salmonella Newport Bacterial Extract vaccine effectively controls infections of Salmonella in dairy animals.

 

Vaccines produced with SRP technology utilize siderophore receptors and porins (SRPs), specialized iron-acquisition proteins found on the outer membrane of the cell wall in Gram-negative bacteria. Bacteria need iron Nearly all Gram-negative bacteria must have an adequate supply of iron if they are to survive,

grow and reproduce. To acquire the necessary iron from the host animal, the bacteria send out  siderophores to acquire or “steal” the iron that is bound to other proteins in the animal’s system.

 

The siderophores carrying this iron re-enter the bacteria cell through the special siderophore receptors,

which are ion channels on the outer membrane of the bacteria. Once inside the cell, the iron is released

and is available for cellular metabolic functions. SRP vaccines are made by culturing Gram-negative bacteria, such as Salmonella, in an iron restricted environment, causing them to develop siderophore receptors.

 

The SRPs are then harvested and separated from the extraneous cellular material like LPS leaving a highly purified extract of SRPs. This extract is not dependent on LPS, lipopolysaccharides (endotoxins),

found in traditional vaccines produced  with whole bacteria cells. The extracted andpurified SRPs are

put in a solutionwith an appropriate adjuvant and are ready for use as a vaccine in animals. When an animal is vaccinated with SRPs, proteins are recognized as antigens and antibodies are produced as part of the normal immune response. The antibodies are then available in the host animal’s immune system and ready to defend the host animal from a challenge by a bacterial pathogen, such as Salmonella.

 

Starving the bacteria The antibodies respond to an infection in the host animal’s system by locking onto,

or blocking, the siderophore receptors and porins on the cell wall of the bacteria, rendering them useless for transporting iron. As a result, the susceptible bacteria that have infected the host become iron deficient and are literally starved to death. Sideophore receptors and porins are what microbiologists call “highly conserved” attributes or  properties of Salmonella bacteria cells. Because their function is critical to the life of the bacteria, nature has caused them to remain nearly identical in structure and function even among different serotypes or strains.