High Prevalence of icaABCD Genes Responsible for Biofilm Formation in Clinical Isolates of Staphylococcus aureus From Hospitalized Children

The icaABCD genes encode a Polysaccharide Intercellular Adhesion (PIA), which is a tight structure protecting Staphylococcus aureus community against adverse environmental conditions. The ica dependent biofilm formation plays an important role in persistent infections in hospitalized patients. The aim of this study was to detect icaADBC genes encoding PIA among S. aureus isolates from children in Loghman Hospital of Tehran. We collected 22 clinical specimens from hospitalized pediatrics and identified the isolates. Then, we detected mecA gene among Methicillin Resistant S. aureus (MRSA), SCCmec types and icaABCD gens by PCR assay and specific primers. Five isolates (22.7%) were methicillin resistant (MRSA) and mecA gene was detected among them. All the MRSA isolates harbored SCCmec type III. Prevalence of icaA, icaB, icaC and icaD in the isolates were 16 (73%), 14 (63.6%), 16 (73%) and 16 (73%), respectively. Moreover, all the MRSA strains were icaADBC positive. Prevalence of icaADBC genes was relatively high among children and also all the four ica genes were detected among MRSA strains.