Production of recombinant proteins including the B-cell epitopes of autolysin A of Staphylococcus aureus isolated from clinical sheep mastitis and their potential for vaccine development

Abstract

Staphylococcus aureus is the most common clinical mastitis-associated pathogen in sheep which contributes to reduced welfare of affected animals and, therefore, compromises the quality and quantity of milk production. To prevent mastitis and its spread, it is essential to guarantee adequate breeding conditions and animal health, through the adoption of good farm management practices and the application of suitable biosecurity measures. Vaccination can play a strategic role in prevention, control, and eradication of diseases. The identification of secreted and cellular antigens of the predominant sheep-CC130/ST700/t1773 lineage would assist in the design of effective vaccine against mammary infections caused by S. aureus. In the current study, we carried out a 3D structural prediction analysis with the identification of the best B cell epitopes of the whole and secreted portion of S. aureus AtlA. Fragments of atlA, containing the main predicted epitopes, were amplified, cloned, and expressed in Escherichia coli for recombinant protein production. Two selected clones produced recombinant proteins (rAtl4 and rAtl8) showing strong reactivity with a hyperimmune serum against the native AtlA and with blood sera collected from sheep with clinical S. aureus mastitis. These may represent potential candidate protein-based vaccines able to elicit a protective immune response to be evaluated by vaccination and subsequent challenge of the vaccinated sheep.

PEI‐PLGA nanoparticles significantly enhanced the immunogenicity of IsdB137‐361 proteins from Staphylococcus aureus

“…Staphylococcus aureus causes multifarious infections in human and animal health, including in human‐related pneumonia, endocarditis, and mastitis in sheep and bovine 1–4 . Over the years, because clinical research have manifested that the vaccine is the most effective strategy in treating S. aureus infection, it is very necessary to develop an effective vaccine against S. aureus , 5–8 however, there is currently a lack of effective vaccine against S. aureus in the market.…”

“…Staphylococcus aureus causes multifarious infections in human and animal health, including in human‐related pneumonia, endocarditis, and mastitis in sheep and bovine. 1 , 2 , 3 , 4 Over the years, because clinical research have manifested that the vaccine is the most effective strategy in treating S. aureus infection, it is very necessary to develop an effective vaccine against S. aureus , 5 , 6 , 7 , 8 however, there is currently a lack of effective vaccine against S. aureus in the market. Our previous research showed that IsdB 137‐361 of the iron surface determinant B protein (IsdB) from S. aureus triggers a strong immune response in animal, but its immunoprotective effect is still to be further promoted.…”