Evaluation of Antibacterial Activity of PHY-ZnONPs against Certain Multi-Drug Resistant (MDR) Bacteria

In recent years, due to the increasing drug resistance and toxicity of many existing drugs the use of bioactive compound to overcome the pathogens has been highly regarded. Phycocyanin is one of the important biocompatible compounds with the significant antibacterial effects. It is the major light-harvesting pigment in cyanobacteria. On the other hand, nanoparticles are a new area to fight the infections. The biogenic synthesis of ZnO nanoparticles using capping potential of bioactive compounds can be a novel strategy to enhance their antibacterial activities. Considering this goal, the antibacterial and antibiofilm activity of phycocyanin-Zinc Oxide nanoparticles (PHY-ZnONPs) was investigated for the first time. Phycocyanin pigment was isolated from a native cyanobacterial strain, Limnothrix sp. KO05. In the following, the manufacturing functionalized phycocyanin, PHY-ZnONPs were synthesized. The antibacterial effect of PHY-ZnONPs evaluated on selected clinical Gram negative ESBL (extended spectrum beta lactamases)-producing E. coli, ESBL Pseudomonas aeruginosa and Gram positive methicillin-resistant bacterium Staphylococcus aureus (MRSA). The effect of PHY-ZnONPs on extracellular polysaccharides (EPS) production by tested clinical isolates showed a definite order of inhibitory effect as follow: E. coli S. aureus P. aeruginosa. PHY-ZnONPs with a high effect against selected clinical MDR isolates can be envisaged as a prospective nanoantibiotic for inhibiting of biofilm formation and bacterial virulence.