Proteomic Changes Occurring in Water Buffalo Milk Upon Intramammary Infection by Staphylococcus aureus and by Non-aureus Staphylococci

摘要

The water buffalo (Bubalus bubalis) is one of the most important non-cow dairy species worldwide. In Italy, buffalo milk is mainly used for producing the appreciated typical cheese "mozzarella di bufala". In view of the limited productions and high value, bacterial mastitis can be a significant problem. Staphylococci are the most frequently isolated species. Staphylococcus aureus (SAU) is the most impacting intramammary pathogen (Guccione et al., 2014), but non-aureus staphylococci (NAS) are also relevant (Moroni et al., 2006). A somatic cell count (SCC) >200,000/mL is a reliable indicator of intramammary infection (IMI) also in buffalo, but low SCC can be observed in culture-positive samples. Therefore, there is a need to understand the impact of staphylococcal IMI on milk quality and to improve its detection to limit therapeutic interventions and antibiotic use. We applied for the first time a shotgun proteomics workflow combining high performance tandem mass spectrometry with label-free quantitation to reveal the changes induced by SAU and NAS IMI on the buffalo milk proteome.