In the “Experimental Study on the Components in Polyvalent “Ghost” Salmonella Vaccine for Veterinary Use” a problem needed to be solved. There were a few strains that were causing Salmonella gastroenteritis or “food poisoning” in humans through poultry products in the UK that were becoming resistant to several antibiotic treatments like ampicillin and gentamicin. These strains were S. Enteritidis and S. Typhimurium. Then another strain S. Newport, discovered in cattle, was causing this disease as well. There was a vaccine on the market that could vaccinate poultry but it wasn’t 100% effective because it treated its “ghost” cells (lacking the bacterial DNA but have preserved cellular morphology) with formalin which caused the lysis and destruction of the cell membrane. This means the cells couldn’t survive long enough to allow the formation of enough antibodies and only included the first two strains mentioned above. A new vaccine needed to be created in order to prevent infection and transmission. There is another treatment which can inactivate the cells, a hybrid nanomaterial based on silver nanoparticles (AgNps) stabilized via polyvinyl alcohol (PVA). The aim of this study was to inactivate the bacteria of the three most common serotypes to create a polyvalent vaccine and maintain the integrity of the cell surface inorder to increase its effectiveness. It was discovered that these three didn’t have silver resistance, each of their Minimal Bactericidal Concentrations (MBC), needed to eliminate bacterial DNA, were under the discovered silver resistance value. There was a large difference between the MBC and the concentration that would inhibit cell viability. This antigen could maintain its viability if the silver solution was rinsed off the antigen after treatment and allowed the creation of multiple antibodies. Since, the cells were still viable this ment it allowed retention of a full range of antigenic determinants thus providing complete protection against the bacteria tested.

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This study is significant because Salmonella has become more and more resistant to the antibiotics medical professionals have readily available. This makes it increasingly difficult to treat humans who get sick from contaminated food or meat. If we can stop the bacteria at its source, the animal/contaminated food, then we can mitigate the amount of people that get sick and the less we have to treat the bacteria with the same antibiotics and risk an incomplete round of treatment. This new way to create “ghost” vaccines means the cell survives longer, allowing the body to create an immunity to the bacteria and stop the transmission from animal to human. This treatment with AgNps instead of formalin means the cell retains its full range of antigenic determinants and if the vaccine is polyvalent, the animal that gets the vaccine can build up an immunity to multiple serotypes of Salmonella and the possibility to fight new ones.

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In class, we discussed the existence of non-human serotypes of Salmonella (an anthropozoonosis) and how this disease can be transmitted from animal to human through touch or byproducts. The main non-human serotype we looked at in class was one of the top three mentioned in this study, S. Typhimurium. Its bacteriophage infection routes included poultry and cattle, like the main culprits in the spread of food poisoning in the UK. The main thing I focused on when I read this study was antibiotic resistance and the incomplete round of treatment that caused it. I liked to see a possible reduction of this problem. It was integral to find a protein or treatment that these serotypes were not resistant to inorder to create the “ghost” cells for the antigen to induce an immune response in the animal's body. The creation of a vaccine would help mitigate the need for antibiotic treatment and help prevent the creation of more antibiotic resistant serotypes of Salmonella.