Evaluating Antibacterial Effects of Silver Nanoparticles on blaTEM Gene Expression in Escherichia Coli Strain Resistant to Beta-Lactam Antibiotic

Introduction: So far, studies have shown that an important reason for Escherichia coli resistance to beta-lactam antibiotics is the presence of broad-spectrum beta-lactamases (ESBLs) which are the product of SHV and TEM gene expression. Some studies also show that the use of nanoparticles can be effective in eliminating bacterial resistance. Therefore, the present study aimed to investigate the effects of silver nanoparticles on the expression of the blaTEM beta-lactamase resistance gene and determin the pattern of antibiotic resistance in existing Escherichia coli samples. Materials and Methods: In this cross-sectional descriptive study, 64 Escherichia coli were collected from 11 medical diagnostic laboratories. These samples were identified using standard laboratory methods and specific cultures. The PCR method was used to evaluate the frequency of the blaTEM gene. To evaluate the antibiotic susceptibility pattern of the strains, the disk diffusion method was performed based on the CLSI protocol. Silver nanoparticles were synthesized from the ginger extract and real-time PCR was used to investigate the effect of silver nanoparticles on blaTEMgene expression. Results: From 64 Escherichia coli resistant samples, 61 samples were beta-lactamase resistant. Phenotypic evaluation of the antibiotic resistance pattern of beta-lactamase-resistant Escherichia coli strains showed that 90% was resistant to penicillin, 66% to carbonicillin, 87% to isolates to erythromycin, 85% to cefotaxime 84% to ceftriaxone, 49% to gentamicin, 37% to spirofloxacin, 22% to imipenem, and 12% to linezolid. The highest antibiotic resistance belonged to penicillin (90%) and erythromycin (87%) and the lowest to imipetmo (22%) and linezolid (12%), respectively. Molecular analysis showed the presence of the blaTEMgene in all samples. The results of the real-time method showed that the effect of silver nanoparticles on blaTEMgene expression was significant. Discussion and Conclusion: The presence of 61 resistant samples out of 64 samples in the present study indicates an increase in the resistance of Escherichia coli to various antibiotics, which could be a serious concern for the treatment of infections caused by Escherichia coli. The effectiveness of silver nanoparticles on blaTEMgene expression suggests that it could be a good alternative to existing antibiotics.