Assessment of the Presence of Sas Family Genes and Their Relationship with Biofilm Formation among Clinical Staphylococcus aureus Isolates

Abstract

Background: The success of Staphylococcus aureus as an important human pathogen is probably due to possession of various virulence determinants. Attachment and biofilm formation is considered the main step in any infection. The present study aimed to determine the presence of S. aureus surface (sas) genes and their association with biofilm formation and antibiotic resistance. Methods: S. aureus isolates collected were analyzed for biofilm formation using polystyrene microtitre plates. All S. aureus isolates were also examined for the determination of sas genes by PCR assays and antibiotic susceptibility assay by disk diffusion method. Results: Biofilm formation assay revealed that 29 S. aureus isolates were weak biofilm producers, 57 had moderate biofilm production, while only five isolates showed strong biofilm formation. The biofilm production was not revealed among nine isolates. The frequency of sas genes were 95 (88%), 94 (87%), 94 (87%), 92 (85.2%), 98 (90.7%), 93 (86.1%), 97 (89.8%), 87 (80.6%), and 85 (78.7%) for sasF, sasA, sasC, sasE, sasG, sasH, sasI, sasJ, and sasK genes, respectively. Conclusion: High incidence of biofilm production was noticed in S.aureus strains positive for sas genes indicating the precise role of them as virulence-associated genes. Moreover, phenotypically weak or moderate biofilm formation can be well managed by antibiotic therapeutics and allow timely elimination of planktonic cells prior biofilm production.

Keywords

• biofilm
• sas genes
• staphylococcus aureus