Biofilm-Associated Gene Expression in Staphylococcus aureus is lineage dependent

Staphylococcus aureus ranks among the most formidable pathogens in human and veterinary settings; its propensity to establish persistent biofilms underlies many chronic infections and recurrent treatment failures. Here, we measured the transcription levels of several biofilm-related genes fnbA, fnbB, clfB, clfA, sarA, sigB, and gyrA across seven robust biofilm-forming clinical isolates, representing sequence types ST2826, ST97, ST2454, and ST6, in static culture. Quantitative data were normalized to the gmk housekeeping gene and interpreted by the 2^-ΔCt computation. Distinct lineage-specific gene signatures emerged: ST2826 isolates favored an adhesin-dominant response, primarily fnbA and clfA; ST97 showed a devotion to regulatory networks with a pronounced sarA bias; ST2454 leaned towards adhesion yet exhibited diminished regulators; and ST6 presented a balanced response, treating regulators and adhesins equally. The observed transcription profiles corresponded well to the biofilm masses measured by the crystal violet method, confirming that the clonal lineage itself establishes the relative direction of adhesion cues, regulatory feedback, or their syndromic balance. Dissecting these lineage-tethered decision circuits elucidates the genomic and phenotypic divergences under the S. aureus biofilm umbrella and should polish the design of selective anti-biofilm strategies in the clinical combat against intractable infections.