Removal of pathogenic bacterial biofilms by combinations of oxidizing compounds

OLMEDO MARÍA GABRIELA; GRILLO PUERTAS MARIANA; CERIONI, LUCIANA; RAPISARDA, VIVIANA A.; VOLENTINI, SABRINA I.

CANADIAN JOURNAL OF MICROBIOLOGY

NATL RESEARCH COUNCIL CANADA-N R C RESEARCH PRESS

Lugar: Otawa; Año: 2015 vol. 61 p. 1 - 6

0008-4166

Bacterial biofilms are commonly formed on medical devices and food processing surfaces. As antimicrobials used have limited efficacy against them, new strategies to prevent and to remove these structures are needed. Here, the effectiveness of brief oxidative treatments, based on the combination of NaClO and H2O2 in the presence of CuSO4, were evaluated against bacterial laboratory strains and clinical isolates, both in planktonic and biofilm state. Simultaneous application of oxidants synergistically inactivated planktonic cells and prevented biofilm formation of laboratory Escherichia coli, Salmonella Typhimurium, Klebsiella pneumoniae, and Staphylococcus aureus strains, and clinical isolates of S. enterica, K. oxytoca and uropathogenic E. coli. In addition, preformed biofilms of E. coli C, S. Typhimurium, K. pneumoniae and S. enterica exposed to treatments were removed applying 12 mg/L NaClO, 0.1 mmol/L CuSO4 and 350 mmol/L H2O2, for 5 min. K. oxytoca and S. aureus required a five-fold increase in NaClO concentration and the E. coli clinical isolate remained irremovable unless treatments were applied on biofilms formed during 24 h instead of 48 h. The application of treatments that last a few minutes using oxidizing compounds at low concentrations represents an interesting disinfection strategy against pathogens associated with medical and industrial settings.