RESUMEN
Nanoemulsion technology is an alternative candidate to overcome antibiotic resistance in pathogenic bacteria. The aim of this research was nanoemulsion production from the essential oil of Alhagi maurorum and the characterization of this nanostructure. Nanoemulsion of essential oil from A. maurorum was prepared using the ionotropic gelation method and chitosan as a nano-carrier. Scanning Electron Microscopy (SEM) was used to characterize the synthesized nanoparticles. The effect of nanoemulsion on the antibacterial, antibiofilm, and plasmid curing of six antibiotic-resistant pathogenic bacteria (P. aeruginosa, E. coli, S. aureus, K. pneumonia, A. baumannii, B. cereus) was evaluated. The results of this study showed that nanoparticles had a spherical shape and smooth topology. The mean size were 172 ± 4 nm and Zeta potentials was +28.6 mv. The results of antibacterial activity confirmed that nanoemulsion of essential oil had higher inhibition against bacteria compared to free essential oil. Also, this nanoemulsion had antibiofilm activity. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration for Biofilm (MBCB) were determined for nanoemulsion against the biofilm of pathogenic bacteria. The results have shown that the MIC value for A. baumannii is 12.5 mg ml -1 and for E. coli this value is 1.75 mg ml -1. This finding means that MIC values were highest for A. baumannii and lowest for E. coli. Statistical analysis demonstrated that the inhibitory effect of nanoemulsion against bacterial biofilm was significant (P < 0.05). This nanoemulsion also had a remarkable effect the curing of R-plasmid of three antibiotic-resistant bacteria. According to GC-MS analysis of A. maurorum essential oil, the main compounds were oxygenated sesquiterpenes and hydrocarbons. Nanoemulsion of A. maurorum had the potential to use as suitable antimicrobial agents against antibiotic-resistant bacteria.
RESUMEN
OBJECTIVES: Microbial biofilms has attracted interest in the recent years because they has become the most important cause of nosocomial infections. This study was aimed to examine the antibacterial activities of Carum copticum extracts on the development of microbial biofilms and planktonic form of six pathogenic bacteria. METHODS: Antimicrobial activity of the crude extracts against the planktonic form of six pathogenic bacteria: Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Acinetobacter baumannii and Klebsiella pneumonia was evaluated by using the disc diffusion method. Minimal Inhibitory Concentration (MIC) and Minimal Bactericidal Concentration (MBC) values was determined by macro-broth dilution technique. Anti-biofilm effects were assessed by microtiter plate method. The chemical composition of the herbal extract was identified by GC-MS. RESULTS: According to disc diffusion test (MIC and MBC) the ability of C. copticum extracts for inhibition of bacteria in planktonic form was confirmed. The best inhibitory effect of this plant on S. aureus and low inhibitory effect on A. baumannii in planktonic forms were observed. These extracts were efficient to inhibit biofilm structures and concentration of each extract has direct relation with inhibitory effect. The maximum and minimum inhibitory effects of C. copticum methanolic extract on biofilm formation were observed on A. baumannii (98%) and K. pneumoniae (19%) respectively. CONCLUSION: The GC-MS analysis revealed that five active compounds were present in the extract of this plant. Data obtained, suggested that the C. copticum extracts applied as antimicrobial agents against these pathogens particularly in biofilm making.