The effect of silver nanoparticles on mecA gene expression in methicillin-resistant samples of Staphylococcus aureus

Staphylococcus aureus is a common cause of nosocomial infections and increased resistance to antimicrobial agents in this bacterium is one of the major problems in health care. We also see resistant strains of this bacterium that are important pathogens in the development of the disease. The control of these bacteria is very important from a health and economic point of view, so the aim of this study was to investigate the prevalence of methicillin mecA resistance gene and determine the pattern of antibiotic resistance in existing samples of Staphylococcus aureus and to evaluate the antibacterial activity of silver nanoparticles against Gram-positive Staphylococcus aureus.

In this cross-sectional study, 59 staphylococcus aureus specimens were collected from 11 nature detection laboratories. These samples were identified using standard laboratory methods and specific culture. PCR was used to evaluate the frequency of mecA gene. In order to use the antibiotic susceptibility pattern of the strains, the disk diffusion method is performed based on the CLSI protocol. Silver nanoparticles were made from ginger extract and Real Time PCR was used to evaluate the effect of silver nanoparticles on mecA gene expression.

Out of 59 samples of Staphylococcus aureus, 51 samples were resistant to methicillin. Phenotypic evaluation of antibiotic resistance pattern of methicillin-resistant Staphylococcus aureus strains showed that the results showed that 90% of isolates to penicillin, 85% to erythromycin, 84% to ceftriaxone, 53% to amikacin, 49% to gentamicin, 47% to piracyl 45% were resistant to spirofloxacin 37% to imipetmo 35% to linezolid, ie the highest antibiotic resistance was to penicillin 90%, erythromycin 85% and the lowest to imipetmo 37% and linzolid 35, respectively. Molecular analysis showed the presence of mecA gene in all samples. The results of real-time study showed that the effect of nanoparticles on mecA gene expression is significant.
Discussion and

The presence of 51 resistant samples out of 59 samples in the present study indicates an increase in resistance of methicillin-resistant Staphylococcus aureus to other antibiotics, which is a serious warning for the treatment of Staphylococcus aureus infections. And the effectiveness of silver nanoparticles on mecA gene expression shows that we can use this substance instead of existing antibiotics.