Evaluation of the synergistic effect of silver nanoparticle with ciprofloxacin against Klebsiella pneumoniae

The worldwide problem of antibiotic resistance and recurrent infections caused by biofilm producing bacteria, has created a threat to treat infections. This study aimed to find a solution for this problem using synergistic mechanism of biosynthesized nanoparticles with antibiotics. A total of 200 clinical and food samples were included in this study. The results revealed that 22 isolates were Klebsiella pneumoniae, 17 of them were multi-drug resistant (MDR). MDR K. pneumoniae isolates were tested for the ability to form biofilm, the results revealed that 94.11% of them were biofilm producers. In this study, the results obtained by PCR technique revealed that mrkA gene is common in the Iraqi isolates of K. pneumoniae. A biological method was used for silver nanoparticles biosynthesis using bacterial supernatant of foodborne Escherichia coli in optimized conditions. Silver nanoparticles were diagnosed by initial indicator of the color change, UV-Visible spectrophotometer, and atomic force microscopy. The results showed the formation of nanoparticles in various shapes, with a diameter ranging from 71.19 nanometers. Silver nanoparticles were effective in inhibiting the growth of MDR K. pneumoniae. In isolates treated with AgNPs + ciprofloxacin a significant reduction was seen in expression of mrkA gene. The data of testing anti-biofilm activity revealed that the combination of silver nanoparticles with ciprofloxacin showed the highest antibacterial activity among the tested treatments