Emerging Role of Gram-Negative Bacteria in Human Mastitis Infection

Mastitis, a prevalent inflammatory condition primarily affecting lactating women, has long been associated with gram-positive bacteria like Staphylococcus aureus . However, emerging evidence underscores the growing role of gram-negative bacteria such as Escherichia coli , Klebsiella pneumoniae , and Pseudomonas aeruginosa in its pathogenesis. These pathogens exhibit unique virulence factors, including endotoxins, biofilm formation, and antimicrobial resistance mechanisms, leading to more severe clinical manifestations and significant therapeutic challenges. Despite their rising clinical importance, gram-negative bacteria remain underexplored in mastitis research, leaving critical gaps in diagnostics, pathogen-specific treatment, and effective disease management. This review highlights the need for intensified research on gram-negative bacteria in mastitis, emphasizing their contribution to disease severity and the impact of multidrug resistance. Addressing these gaps is essential to advancing diagnostic accuracy, developing targeted therapeutics, and improving patient outcomes in this increasingly complex condition.