The activity of Selenium nanoparticles in combination with Azithromycin on Gene Expression and Genetic Variations of icaB and mecA of MDR Staphylococcus aureus.

Abstract

Background. Methicillin-resistant Staphylococcus aureus (MRSA) is a serious community well-being risk because of its amplitude for biofilm creation and antibiotic resistance. Aims. The current study estimated the efficiency of selenium nanoparticles (SeNPs) unaccompanied and in mixture with azithromycin (AZM) in altering the expression of biofilm-associated (icaB) and methicillin resistance (mecA) genes in S. aureus MRSA isolates. Methods. Three Staphylococcus aureus MRSA isolates were selected out of total seventeen isolates. Cultured in concentrations of 8 µg/mL AZM, 0.125 µg/mL SeNPs, and their mixture (SeNPs-AZM) were investigated by q-PCR, followed by DNA sequencing analysis. Results. Quantitative PCR analysis showed that SeNPs and SeNPs-AZM significantly down-regulated icaB (mean fold change: SeNPs, 0.222; SeNPs-AZM, 0.077) and mecA (mean fold change: SeNPs, 0.1613; SeNPs-AZM, 0.105), with P<0.05 used for all groups in comparison with control. on the other hand, AZM without SeNPs upregulated both genes with mean of fold change (icaB, 2.222; mecA, 2.5022). Sequence analysis revealed that SeNPs-AZM promoted the maximum number of mutations, which encompassing semi-conserved, conserved missense, and silent mutations, fulfilling in 3% nucleotide and 25% protein variations for icaB and 1% nucleotide and 2% protein variations for mecA. Conclusions. These results established the latent of SeNPs, particularly when mixed with AZM, to decrease biofilm creation and antibiotic resistance by damaging bacterial controlling mechanisms, supplying a talented approach antagonistic toward multidrug-resistant MRSA infections.