Pseudomonas aeruginosa Biofilm Antibiotic Resistance Gene Expression Requires the RpoS Stationary-Phase Sigma Factor.

Chronic, biofilm-based bacterial infections are exceptionally difficult to eradicate due to the high degree of antibiotic recalcitrance exhibited by cells in biofilm communities. In the opportunistic pathogen , biofilm recalcitrance is multifactorial and arises in part from the preferential expression of resistance genes in biofilms compared to exponential-phase planktonic cells. One such mechanism involves , which we have previously shown to be expressed specifically in biofilms.

Pseudomonas aeruginosa tssC1 links type VI secretion and biofilm-specific antibiotic resistance.

Biofilm-specific antibiotic resistance is influenced by multiple factors. We demonstrated that Pseudomonas aeruginosa tssC1, a gene implicated in type VI secretion (T6S), is important for resistance of biofilms to a subset of antibiotics. We showed that tssC1 expression is induced in biofilms and confirmed that tssC1 is required for T6S.