Molecular detection of virulence factors (adhesion genes) in some Staphylococcus epidermidis locally isolated from different clinical sources

The icaA and icaD genes are found in bacterial cells. The icaA and icaD genes allow a bacterium to produce biofilm. Biofilms are an important virulence determinant in bacteria because biofilm formation significantly increases resistance to antibiotics and promotes host defenses. The ability of biofilm production can be determined by two phenotypic methods and genotypic methods of some adhesion factors (icaA and icaD). The phenotypic methods included the Congo-red agar (CRA) and Microtiter plate (Mtp). The results showed that 58 (69%) from 84 isolates were positive for producing biofilm on (CRA) plates and the 55 (65%) from 84 isolates were positive for adhesion and biofilm formation by (Mtp) on the O.D. 490nm. The extraction of DNA is subjected to use for polymerase chain reaction (PCR) which is used to amplify specific genes. The production of viscous layer of Staphylococcus epidermidis was investigated by using Molecular analysis (PCR) monoplex to amplify the virulence factor (icaA, icaD) genes (adhesion factors) with the amplicon sizes 188 bp and 198 bp, respectively. The results of the genes icaA and icaD represented as sixty for (46) 54.8% and thirty (30) 35.7%, respectively. The conclusion to these study detection to icaA and icaD genesis important virulence factor.