Department of Animal Science, University of Tennessee, Knoxville, TN 37996, USA; East Tennessee AgResearch and Education Center-Little River Animal and Environmental Unit, University of Tennessee, Walland, TN 37886, USA.
Department of Animal Science, University of Tennessee, Knoxville, TN 37996, USA.
Vaccine. 2024 Feb 27;42(6):1247-1258. doi: 10.1016/j.vaccine.2024.01.067. Epub 2024 Jan 27.
Mastitis is an inflammation of the mammary gland commonly caused by bacteria or fungi. Staphylococcus aureus is a major bacterium that causes mastitis in dairy cows. Non-aureus staphylococci are also increasingly reported, with Staphylococcus chromogenes being the most common species. Current staphylococcal mastitis control programs are not fully effective, and treatment with antibiotics is not sustainable. Non-antibiotic sustainable control tools, such as effective vaccines, are critically needed. We previously developed S. aureus surface-associated proteins (SASP) and S. chromogenes surface-associated proteins (SCSP) vaccines that conferred partial protective effects. We hypothesized that vaccination with SASP or SCSP would reduce the incidence of S. aureus mastitis throughout the lactation period. The objective of this study was to evaluate the efficacy of SASP and SCSP vaccines against S. aureus and non-aureus staphylococcal mastitis under natural exposure over 300 days of lactation. Pregnant Holstein dairy cows (n = 45) were enrolled and assigned to receive SASP (n = 15) or SCSP (n = 16) vaccines or unvaccinated control (n = 14). Cows were vaccinated with 1.2 mg of SASP or SCSP with Emulsigen-D adjuvant. Control cows were injected with phosphate-buffered saline with Emulsigen-D adjuvant. Three vaccine injections were given subcutaneously at 60, 40, and 20 days before the expected calving. Booster vaccinations were given at 120 and 240 days in milk. Cows were monitored for mastitis at quarter and cow levels, staphylococcal mastitis incidence, changes in serum and milk anti-SASP and anti-SCSP antibody titers, bacterial counts in milk, adverse reactions, milk yield and milk somatic cells count over 300 days of lactation. The SCSP vaccine conferred a significant reduction in the incidence of staphylococcal mastitis. Milk and serum anti-SASP and anti-SCSP antibody titers were increased in the vaccinated cows compared to unvaccinated control cows. Anti-SASP and anti-SCSP antibody titers decreased at about 120 days in milk, indicating the duration of immunity of about four months. In conclusion, the SASP and SCSP vaccines conferred partial protection from natural infection.
乳腺炎是一种常见的乳腺炎症，通常由细菌或真菌引起。金黄色葡萄球菌是导致奶牛乳腺炎的主要细菌。非金黄色葡萄球菌也越来越多地被报道，其中产色葡萄球菌最为常见。目前的葡萄球菌乳腺炎控制方案并不完全有效，抗生素治疗也不可持续。非常需要非抗生素可持续控制工具，如有效的疫苗。我们之前开发了金黄色葡萄球菌表面相关蛋白（SASP）和产色葡萄球菌表面相关蛋白（SCSP）疫苗，这些疫苗具有部分保护作用。我们假设接种 SASP 或 SCSP 疫苗可以降低泌乳期金黄色葡萄球菌乳腺炎的发病率。本研究的目的是评估 SASP 和 SCSP 疫苗在 300 天泌乳期内自然暴露下对金黄色葡萄球菌和非金黄色葡萄球菌乳腺炎的疗效。招募了怀孕的荷斯坦奶牛（n=45），并分配接受 SASP（n=15）或 SCSP（n=16）疫苗或未接种疫苗的对照（n=14）。奶牛用 1.2mg 的 SASP 或 SCSP 与 Emulsigen-D 佐剂进行皮下接种。对照牛注射磷酸盐缓冲盐水与 Emulsigen-D 佐剂。在预计分娩前 60、40 和 20 天，分 3 次皮下注射疫苗。在产奶 120 和 240 天进行加强免疫。在乳房和奶牛水平上监测乳腺炎，金黄色葡萄球菌乳腺炎的发病率，血清和牛奶中抗 SASP 和抗 SCSP 抗体滴度的变化，牛奶中的细菌计数，不良反应，产奶量和牛奶体细胞计数超过 300 天的泌乳期。SCSP 疫苗显著降低了金黄色葡萄球菌乳腺炎的发病率。与未接种疫苗的对照奶牛相比，接种疫苗的奶牛牛奶和血清中的抗 SASP 和抗 SCSP 抗体滴度增加。抗 SASP 和抗 SCSP 抗体滴度在产奶约 120 天时下降，表明免疫持续时间约为四个月。总之，SASP 和 SCSP 疫苗对自然感染具有部分保护作用。
