PRDX5 and cystic fibrosis: The only gene showing higher expression in the non-CF isolates compared to CF isolates was spxA, a transcription regulator involved in the biosysnthesis of thioredoxin reductase, an enzyme found down-regulated during treatment with hypochlorite [32] or in the presence of berberine chloride [33] and whose deletion yields to the accumulation of biofilm onto surface.