The Study of blaZ and mecA Gene Expression in Methicillin-Resistant Staphylococcus Aureus Strains and the Relationship between the Gene Expression Patterns

Abstract

Background: Resistance to beta-lactams is the most important feature in Staphylococcus aureus (S. aureus). There is a possibility that the amount of resistance and beta-lactam antibiotic resistance gene expression are different in Staphylococcus resistant strains. The aim of this study was to determine the expression of mecA and blaZ genes in methicillin-resistant S. aureus and the relationship between gene expression patters. Methods: In this experimental-analysis study, 120 clinical isolates of methicillin-resistant S. aureus were isolated from different clinical samples using phenotypic tests. To study the quality of the mecA and blaZ genes in resistant isolates, polymerase chain reaction (PCR) was used. In addition, the quantity of genes, SYBR-Green-1-based real-time PCR was applied. REST 2008 and SPSS software were used to analyze the data. Findings: Out of 120 isolates of methicillin-resistant S. aureus, 105 isolates (87.5%) had blaZ gene. The most diverse gene expression changes in sample type were seen in blood and urine samples. So, the expression on the wound and urine clinical samples was dramatically more than the other sites. In addition, significant relationship was observed between the blaZ and mecA gene expression and the kind of clinical samples. Conclusion: The results of this study suggested that different doses of antibiotics should be used to treat staphylococcal infections in different organs.

Keywords

• Gene expression
• Beta-lactams
• Antibiotic resistance
• Methicillin-resistant
• Staphylococcus aureus