Biological methods employed plant extracts, bacteria, and fungi , with studies on CuNPs and AgCuNPs targeting udder inflammation pathogens like Staphylococcus aureus and Escherichia coli . Antimicrobial resistance is a persistent natural occurrence, exacerbated by factors such as excessive and illicit antimicrobial use, inappropriate dosage, sub-therapeutic dosing, and noncompliance with prescribed treatment courses .