Green synthesized copper nanoparticles and their anti-bacterial properties against bullfrog multidrug resistant gram negative bacteria

Abstract

The emergence of multidrug-resistant (MDR) gram-negative bacteria in bullfrog (Hoplobatrachus rugulosus) farming has been increasing dramatically which resulted in searching for new types of antimicrobial agents. Although some new drugs against MDR bacteria have been introduced or presently in clinical trials, the efficiency of them are still limited by species of pathogens. Therefore, copper nanoparticles (CuNPs) has been immerged in MDR treatment due to their greater exhibition in broad-spectrum bactericidal properties. To prepare green synthesized CuNPs, the high antioxidant property of plant aqueous extracts assessed by scavenging free radicals of DPPH and Reducing Power (RP) of ferric(III)chloride were used. It was indicated that the IC50 value of extract was greatest in Garcinia mangostana following Camellia sinensis, Phyllanthus urinaria, P. amarus and P. virgatus, respectively ranging from 230±10 to 490±10 (µg/mL) and positive related to RP antioxidant activities. The formation CuNPs were characterized using UV-visible spectroscopy revealed a maximum absorbance at 340 nm. CuNPs using G. mangostana (GM-CuNPs) exhibited the greatest significant bactericidal activity against multi-drug resistant gram negative bacterial strains such as Aeromonas sorbia, Edwardsiella tarda, Enterobacter spp., Klebsiella pneumoniae, and Pseudomonas spp. by agar well diffusion method. Moreover, the results from Dynamic light scattering (DLS) demonstrated that only size of GM-CuNPs was in the nano-size range of 254±144.9 nm whereas the zeta potential was in the range of -0.37±11.3 mV. It can be concluded that GM-CuNPs exhibit greatest antibacterial properties for MDR treatment and should be a candidate for future bullfrog MDR therapeutic application. In vivo research and cost-effectiveness analysis will be also investigated for further study.