Invastigation of 16S rRNA, mecA and nuc genes in coagulase-positive and negative Staphylococci by Real-Time PCR

Abstract

Objective: Staphylococcus aureus is a Gram-positive and round-shaped bacterium. It is often positive for catalase and nitrate reduction. Pathogenic isolates support infections by producing protein toxins and the expression of a cell-surface protein virulence factors. Sepsis-related to methicillin-resistant S. aureus (MRSA) has significant morbidity and high mortality rates (15-30%). The methicillin resistance for S. aureus is coded with the MecA gene, while the methicillin sensitivity is coded with the Nuc gene, and they are chromosomal. Similarly, it is coded with the coagulase gene for S. aureus (Coa). Materials and Methods:In this study, the 16S rRNA gene identification by Real-Time PCR was investigated in forty S. aureus isolates, which were cultured at different times in terms of MIC and SIR tests. The isolates used in the study were determined at the gene level in terms of their differences in methicillin resistance gene (MecA), methicillin susceptibility gene (Nuc), coagulase gene (Coa) and intraspecies differences were examined. Results:As a result of the study, Staphylococcus spp. yielded positive results with 16S rRNA gene-specific primers in all isolates. Real-Time PCR analysis of the isolates with SYBRGreen-based PCR analysis was performed with 16S rRNA gene-specific primers, and the samples were confirmed to be Staphylococcus. Analysis at the family level was followed by Coa, Nuc, and MecA gene Real-Time PCR results, and it was found that, in terms of Coa and Nuc genes, 19 isolates were positive and 21 isolates were negative. In terms of MecA gene, 16 isolates were positive according to the positive sigmoidal curves and to the single peak melting values, whereas 24 isolates were found to be negative. Conclusion:It is thought that this study will benefit the community by contributing to the rapid and effective treatment and diagnosis of infections caused by coagulase-positive/negative Staphylococci.

Cross-sectional analysis of risk factors associated with Mugil cephalus in retail fish markets concerning methicillin-resistant Staphylococcus aureus and Aeromonas hydrophila

“…The PCR study of mecA genes (encoding methicillin resistance) and nuc genes (encoding staphylococcal thermostable nuclease) is considered a quick MRSA strain identification approach (Sahebnasagh et al, 2014). The 23S rRNA gene was found in 100% of the S. aureus isolates in this study, which was similar to recent findings from Turkey (Aksakal et al, 2022) and India (Murugadas et al, 2016). The nuc gene was detected in 80% of screened S. aureus isolates.…”

“…The highest prevalence (100%) was earlier reported in India (Murugadas et al, 2016), and prevalence of 90% and 100% was reported in Egypt (Elkamouny et al, 2020;Anjusha et al, 2022, respectively), whereas the lowest prevalence (14.43% and 60%) was reported by prior studies on S. aureus isolated from fish (Mohammed et al, 2020;Aksakal et al, 2022, respectively). With regard to our finding, the prevalence of mec gene (60%) was higher than those in prior studies that reported prevalence of 44% (Elkamouny et al, 2020), 10.30% (Mohammed et al, 2020), 47.5% (Aksakal et al, 2022), and 1.8% (Anjusha et al, 2022) in S. aureus isolated from fish but lower than the 100% reported in India (Murugadas et al, 2016).…”