Genome sequences of Mastitis Isolates interactions
Background: Mastitis, an inflammatory disease of the mammary gland, poses a significant challenge in the dairy industry due to its economic impact and implications for animal welfare. Staphylococcus aureus is one of the major pathogens responsible for contagious mastitis. The problematic nature of S. aureus is related to its ability to persist in the mammary gland and limited responsiveness to antibiotic treatment. In contrast, the role of non–aureus staphylococci and mammaliicocci (NASM) in bovine mastitis is less well understood, despite their frequent isolation from milk and occasional co-occurrence with S. aureus. Methods: This study aimed to characterize the proteomic response of S. aureus during growth in milk in monoculture and in coculture with selected NASM species (Staphylococcus chromogenes and Staphylococcus epidermidis), to identify protein expression changes associated with interspecies interactions. A bottom-up proteomic approach with gel-free sample preparation was employed. Bacterial cultures were grown in milk to mimic the udder environment, and proteomic profiles of samples collected at multiple time points were analyzed by LC-MS/MS.  Results: A total of 933 S. aureus proteins were detected across all samples approximately 40% of the predicted proteome, including most proteins essential for survival in milk. Differential protein expression analysis showed significant changes in the S. aureus proteome in monoculture compared to both cocultures. The presence of NASM was associated with changes in multiple pathways, with nearly 30 proteins (approximately 3% of detected proteins) showing differential expression.  Conclusions: The presence of NASM was associated with measurable changes in the S. aureus proteome in milk, with more pronounced effects observed in co-culture with S. chromogenes. These findings indicate that interspecies interactions may influence proteomic profiles under the tested conditions. However, the implications of these changes for mastitis development and in vivo dynamics remain to be determined.
Background: Mastitis, an inflammatory disease of the mammary gland, poses a significant challenge in the dairy industry due to its economic impact and implications for animal welfare. Staphylococcus aureus is one of the major pathogens responsible for contagious mastitis. The problematic nature of S. aureus is related to its ability to persist in the mammary gland and limited responsiveness to antibiotic treatment. In contrast, the role of non–aureus staphylococci and mammaliicocci (NASM) in bovine mastitis is less well understood, despite their frequent isolation from milk and occasional co-occurrence with S. aureus. Methods: This study aimed to characterize the proteomic response of S. aureus during growth in milk in monoculture and in coculture with selected NASM species (Staphylococcus chromogenes and Staphylococcus epidermidis), to identify protein expression changes associated with interspecies interactions. A bottom-up proteomic approach with gel-free sample preparation was employed. Bacterial cultures were grown in milk to mimic the udder environment, and proteomic profiles of samples collected at multiple time points were analyzed by LC-MS/MS.  Results: A total of 933 S. aureus proteins were detected across all samples approximately 40% of the predicted proteome, including most proteins essential for survival in milk. Differential protein expression analysis showed significant changes in the S. aureus proteome in monoculture compared to both cocultures. The presence of NASM was associated with changes in multiple pathways, with nearly 30 proteins (approximately 3% of detected proteins) showing differential expression.  Conclusions: The presence of NASM was associated with measurable changes in the S. aureus proteome in milk, with more pronounced effects observed in co-culture with S. chromogenes. These findings indicate that interspecies interactions may influence proteomic profiles under the tested conditions. However, the implications of these changes for mastitis development and in vivo dynamics remain to be determined.