RT Journal Article T1 Clearance of mixed bioflms of Streptococcus pneumoniaeand methicillin‑susceptible/resistant Staphylococcus aureusby antioxidants N‑acetyl‑l‑cysteine and cysteamine. A1 Sempere, Julio A1 Llamosí, Mirella A1 Román, Federico A1 Lago, Darío A1 González Camacho, Fernando A1 Pérez García, Covadonga A1 Yuste, José A1 Domenech Lucas, Mirian AB Bioflm-associated infections are of great concern because they are associated with antibiotic resistance and immune evasion. Co-colonization by Staphylococcus aureus and Streptococcus pneumoniae is possible and a threat in clinical practice. We investigated the interaction between S. aureus and S. pneumoniae in mixed bioflms and tested new antibioflm therapies with antioxidants N-acetyl-l-cysteine (NAC) and cysteamine (Cys). We developed two in vitro S. aureus–S. pneumoniae mixed bioflms in 96-well polystyrene microtiter plates and we treated in vitro bioflms with Cys and NAC analyzing their efect by CV staining and viable plate counting. S. pneumoniae needed a higher proportion of cells in the inoculum and planktonic culture to reach a similar population rate in the mixed bioflm. We demonstrated the efect of Cys in preventing S. aureus bioflms and S. aureus–S. pneumoniae mixed bioflms. Moreover, administration of 5 mg/ml of NAC nearly eradicated the S. pneumoniae population and killed nearly 94% of MSSA cells and 99% of MRSA cells in the mixed bioflms. The methicillin resistance background did not change the antioxidants efect in S. aureus. These results identify NAC and Cys as promising repurposed drug candidates for the prevention and treatment of mixed bioflms by S. pneumoniae and S. aureus. PB Nature publishing group SN 2045-2322 YR 2022 FD 2022-04-23 LK https://hdl.handle.net/20.500.14352/71854 UL https://hdl.handle.net/20.500.14352/71854 LA eng NO Ministerio de Economía, Industria y Competitividad (MINECO) NO Ministerio de Ciencia e Innovación (MICINN) DS Docta Complutense RD 10 abr 2025