Genotypic estimation of the biofilm formation of Staphylococcus aureus (MRSA) isolates from dental staff


  • Nadia Q. Mahmood, Najwa Ibrahim Khaleel, Ghada Younis Abdulrahman


MRSA , Biofilm , mecA , Adhesion gene , Dental staff.


In this research, the six isolates of Staphylococcus aureus isolated from dental workers (dentists and assistants) were taken and diagnosed in another research which is under publication, to study its genetic estimation and its ability to form biofilms by plate Microtiter method. The results showed  that all  Staphylococcus aureus isolates have the ability to form biofilms because they own the genes icaA and icaD  except the isolate number one which have the gene icaD so it gives a slight or thin biofilm  . The isolates were also molecularly diagnosed using the Polymerase Chain Reaction (PCR) technique, and the results showed that 3\6 (50%) isolates of S.aureus bacteria were resistant to methicillin due to their possession of the mecA gene that encodes the resistance to the antibiotic methicillin. In addition, they possessed the icaA and icaD genes responsible for the formation of biofilms with percentages of (83.3 and 100)%, respectively, and it was found that (83.3%) of these isolates contained the icaA and icaD genes, but they did not contain the qacA\B gene., while they possessed the Smr gene with a percentage of (16.6%) of the total number of the six isolates under study.