*8.1.3 Other formulations/approaches*

After experimental infection, it was found that different formulations of bacterial drugs that kill whole cells can reduce the number of infections and a quarter of SCC, but this effect was only reported 13 days after infection. Subsequent field reports of two doses at the same time, lower doses in cattle and additional doses during the subsequent lactation period may produce higher antibodies against *Staphylococcus aureus*. Researchers also report that vaccinated animals consume an average of 0.5 kg of milk per day and have lower SCC levels. In this study, Freund's incomplete adjuvant was used as part of the first biphasic administration. This adjuvant is known to cause significant injection site reactions and is not commonly used in commercial products. More interesting developments from the same research group have identified targets for RNAIII-activated protein (TRAP), a highly conserved membrane protein in many *Staphylococcus* species, including *Staphylococcus aureus*. This antigen can become a specific and universal vaccine against *staphylococcus* [81]. *Staphylococcus aureus* produces adhesin, a pathogenic factor that promotes attachment of host tissues and subsequent attachment between bacterial cells, creating a biofilm that can resist feeding. Surface polysaccharides are an important component of staphylococcal biofilm, and strains expressing high levels of extracellular polysaccharides (surfaceassociated antigenic complex [SAAC]) have been isolated [82]. A commercial formulation combining SAAC *Staphylococcus aureus* and *E. coli* has been approved by the European Union. Clinical reports have shown that this product can improve udder health by reducing re-infection and SCC in vaccinated animals. The use of vaccines against *Staphylococcus aureus* may be restricted in many dairy farms, especially herds with low IMI prevalence, such as herds with SCC <200,000 cells/ ml. Thus, *Staphylococcus aureus* bacteriosin cannot significantly influence the successful control of infectious mastitis through the use of correct milking techniques and milking machine maintenance. Conversely, people who have been vaccinated with the right treatment can experience disappointing results. As previously mentioned, this varies greatly between herds and geographic areas. If the herd has *Staphylococcus aureus*, bacteriosin can also reduce the shedding of bacteria in the milk of infected animals. Researchers have administered *Staphylococcus aureus* bacteriosin to improve antibacterial treatment, but the results are mixed [83].
