Prevalence and Expression of Genes of Type II Antitoxin Toxin Systems in Clinical Isolates of Methicillin-Resistant Staphylococcus aureus

Objectives: Antibiotic resistance of bacteria has been increasing in recent years and reports indicate that some bacterial strains are even resistant to the last treatment line. The survey of MazEF antitoxin-toxin genes in 84 strain of MRSA and and the antimicrobial effect of supernatants on the logarithmic growth stage of the bacteria.&#x0D; Methods: In this study, 84 strains of MRSA were collected. The patients included 48 males and 36 females with a mean age of 39 years.  The primers for Staphylococcus aureus type II antitoxin genes were designed. In the first step, using the mecA primer and PCR, the strains were genetically examined to confirm methicillin-resistant Staphylococcus aureus. In the next step, the frequency of MazEF antitoxin-toxin genes was examined.&#x0D; Results: All strains of methicillin-resistant Staphylococcus aureus had the F maz gene except one. The highest antibiotic resistance was related to the strains isolated from the wound and the lowest resistance was related to the strains isolated from the urine. the effect of the supernatant obtained in the death phase of Staphylococcus aureus was assessed and the antimicrobial effect of these supernatants on the logarithmic growth stage of the bacteria was measured.&#x0D; Conclusion: since previous studies showed the antimicrobial effect of this supernatant on many other bacteria, a type II system was suspected that was confirmed by the results.</jats:p