Molecular detection of CRISPR-Cas system in Staphylococcus aureus isolated from different sources

Abstract

The goal of this work was to look into the CRISPR-Cas system in the genome of Staphylococcus aureus. To do this, local strains of Staphylococcus aureus bacteria were isolated from several samples and examined for confirmation of Staphylococcus spp. detection. Using the BLAST tool, the partial sequencing of the 16S rRNA gene data was evaluated and compared to those in GenBank to determine the sequence variance. The sequence results were 9 samples classified as Staphylococcus aureus, which were utilized to build a phylogenetic tree to assess the similarities and differences between local isolates and existing international isolates. The CRISPR-Cas were investigated in all isolates of Staphylococcus spp. (non-aureus Staphylococcus and Staphylococcus aureus), the cas6 element was not detected in all investigated bacterial strains, while SECR1 and SECR2 were detected in 18 and 12 species of Staphylococcus spp. respectively. Moreover 6 isolates of confirmed Staphylococcus aureus were found to have SECR1 and SECR2 elements. We concluded that the CRISPR-Cas system can be detected in S. aureus isolates from various local sources of samples, and that the appearance of the CRISPR system in S. aureus isolates is lower than the expected average for bacteria in general, implying that CRISPR loci or the CRISPR-Cas system in S. aureus may be mobile genetic elements.