Klebsiella pneumoniae is an important gram-negative opportunistic pathogen that causes a variety of infectious diseases, including urinary tract infections, bacteremia, pneumonia, and liver abscesses. In this study, Klebsiella pneumoniae strain KP2211 was isolated, identified, and subjected to in vitro assessment of its antibiotic sensitivity testes, and in silico predicted synergistic combination between antibiotic resistance profile with retrative polyhydroxyalkanoates compounds against important receptor protein play important role in multi-drug resistance treatment in Gram negative bacteria.  Polyhydroxyalkonates (PHAs) are a class of naturally occurring, biodegradable polymers synthesized by various microorganisms as intracellular energy storage materials under conditions of nutrient imbalance. These polymers are composed of hydroxyalkanoate monomers and are characterized by their biocompatibility, biodegradability, and versatile material properties, making them suitable for a wide range of applications in biomedical fields (e.g., drug delivery, tissue engineering, and medical implants) and environmental sectors (e.g., biodegradable plastics, packaging, and agricultural films). The antibiotic susceptibility test reported that klebsiella pneumoniae strain KP2211 showed the highest resistance against different antibiotics as Amoxycillin (AMX), Cefepime (FEP), Vancomycin (VA), Cefoxitin (FOX), Ceftazidime (CAZ), Cefazoline (CZ), Trimethoprim/Sulfamethoxazole (SXT) and Clindamycin (CD). In addition, the prediction of a synergistic effect of PHAs ingredients as 9,12-Octadecadienoic acid (z, z) methyl ester and resistance antibiotic against LpxC enzyme in the lipid A biosynthetic pathway, showed a promising binding affinity ranging from -6.9 to -9.0  kcal/ mol. Our findings indicated that predicted molecules are a promising way to be used as a drug delivery system for multi-drug resistance in pneumonia treatment.