Correlation between Ica Locus and Different SCCmec Types in Clinical Isolates of Methicillin-Resistant Staphylococcus Aureus: An Analytical-Descriptive Study

In clinical isolates of Staphylococcus aureus, the ica locus plays an important role in biofilm formation. However, its function in S. aureus clinical isolates carrying SCCmec locus and drug resistance is not clearly defined. This study aimsto measure the correlation between the ica locus and different types of SCCmec in clinical isolates of methicillin-resistant S. aureus (MRSA).

In this descriptive-analytical study, 89 isolates of S. aureus were isolated from different clinical samples using biochemical tests. Antibiotic resistance patterns and MRSA strains were identified by the disc diffusion method. SCCmec and ica locus was investigated using the PCR method.

Out of 89 clinical isolates of S. aureus, 41 MRSA strains were identified. The frequency of SCCmecI, SCCmecII, SCCmecIII, SCCmecIV, and SCCmecV genes was 21.9%, 26.8%, 31.7%, 17.1%, and 41.4%, respectively. In addition, icaA, icaB, icaC, and icaD were isolated from 29 isolates (32.58%), 11 isolates (12.35%), 17 isolates (19.10%),and 22 isolates (24.71%), respectively. The frequency of SCCmec types in the strains carrying the ica locus was significantly higher than in the strains without the ica locus (P≥0.05).

The circulation of ica locus genes plays a vital role in increasing the frequency of methicillin-resistant S. aureus strains and the distribution of SCCmec types in those strains.