Resilient Staphylococcus aureus in Mastitis Milk: Insights into Antibiotic Resistance and Biofilm Formation

Background: Staphylococcus aureus is capable of producing a wide range of virulence factors. It is a deadly bacterium that is resistant to the majority of antibiotics that are typically provided. The ability of S. aureus to establish chronic, implant associated infections and our inability to cure them, is directly associated with its biofilm formation, creating an environment where bacteria can grow and persist while protected from the host immune response and antibiotic therapy. Antibiotic resistance of S. aureus is widely spreading with low cure rate. Methods: A total of 62 S. aureus strains were isolated from animal pus, human pus, animal skin, human skin, mastitic milk, normal milk and unprocessed meat samples. The isolates were genotypically confirmed by 23S rRNA ribotyping for S. aureus. Using 14 antibiotics belonging to different generations were tested for their resistance pattern from various sources. Result: All the mastitic milk, animal pus, human pus and unprocessed meat S. aureus isolates from all the places of sampling showed 100% sensitivity towards imipenem while isolates obtained from mastitic milk, human skin, animal skin showed 100% resistance towards ampicillin and ampicillin+sulbactum combination.