Objective   To investigate the correlation of biofilm forming ability with biofilm associated gene of the clinically isolated Staphylococcus aureus for providing basis for the further studies of the mechanisms of biofilm formation.   Methods   Safranine staining was conducted for the detection of the forming ability of biofilm in 96-well plates. icaAD

icaBC

sar

agr and sigB was amplified by PCR.   Results   Formation of biofilm could be found macroscopically in 17 out of 27 strains

especially to X387 and X409. icaAD and icaBC were amplified in 22 isolates and sar

agr and sigB in all 27 S. aureus strains.   Conclusion   ica operon is the key gene for biofilm formation but cooperative action of other genes is needed during the process of biofilm formation.