K11 is an antimicrobial peptide. K11 is active against MDR/XDR K. pneumoniae isolates (MIC: 8-512 μg/mL), and inhibits bacterial biofilm formation. K11 can act synergistically with antibiotics (Chloramphenicol , Meropenem , Rifampicin , etc.) against drug-resistant K. pneumoniae. K11 has high thermal and wide pH stability.