عنوان مجله
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APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
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چکیده
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The bactericidal effects of silver nanoparticles have
been demonstrated in the past years. Recently, the new antimicrobial compounds of silver nanoparticles with different
formulations have been developed. In this work,
AgClNPs@SBA-15/IL as a new compound of Ag nanoparticles, was synthesized and characterized by XRD, TEM, SEM,
FTIR, and EDX. The antibacterial activity and the molecular
mechanism effects of AgClNPs@SBA-15/IL nanoparticles
(SNPs) on Escherichia coli DH5α cells were investigated by
analyzing the growth inhibitory, H2O2 level, catalase activity,
DNA mutation, and plasmid copy number following treatment with AgClNPs@SBA-15/IL nanoparticles. In experimental results, the minimum inhibitory concentration (MIC) was
observed in 75 μg/ml and the antibacterial efficacy (ABE) in
CFU analysis was estimated 95.3 %. In bacterial cells treated
with 75 and 100 μg/ml, H2O2 level significantly increased and
catalase activity decreased compared with control. The random amplified polymorphic DNA (RAPD) was used to evaluate the effect of AgClNPs@SBA-15/IL nanoparticles in DNA
damages and mutation in E. coli genome. RADP-PCR results
indicated different banding patterns including appearance or
disappearance of bands and differences in their intensity.
Cluster analysis of the RAPD-PCR results based on genetic
similarity showed genetic difference between E. coli cells
treated with AgClNPs@SBA-15/IL nanoparticles, and control
and phylogenetic tree were divided to two clusters. Plasmid
copy number analysis indicated that after 8 h incubation of
E. coli cells with 50, 75, and 100 μg/ml AgClNPs@SBA-15/IL
nanoparticles, copy number of pET21a (+) significantly decreased compared with control which indicating DNA replication inhibition by Ag nanoparticles. In conclusion, the results of this study indicated that AgClNPs@SBA-15/IL nanoparticles can be used as an effective bactericidal agent against
bacterial cells.
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