Removal of pathogenic bacterial biofilms by combinations of oxidizing compounds

OLMEDO, GABRIELA M.; GRILLO PUERTAS, MARIANA; CERIONI, LUCIANA; RAPISARDA, VIVIANA ANDREA; VOLENTINI, SABRINA INÉS

CANADIAN JOURNAL OF MICROBIOLOGY

NATL RESEARCH COUNCIL CANADA-N R C RESEARCH PRESS

Lugar: Otawa; Año: 2015 vol. 61 p. 351 - 356

0008-4166

: Bacterial biofilms are commonly formed on medical devices and food processing surfaces. The antimicrobials used havelimited efficacy against the biofilms; therefore, new strategies to prevent and remove these structures are needed. Here, the effectivenessof brief oxidative treatments, based on the combination of sodium hypochlorite (NaClO) and hydrogen peroxide (H2O2) in thepresence of copper sulfate (CuSO4), were evaluated against bacterial laboratory strains and clinical isolates, both in planktonic andbiofilm states. Simultaneous application of oxidants synergistically inactivated planktonic cells and prevented biofilm formation oflaboratory Escherichia coli, Salmonella enterica serovar Typhimurium, Klebsiella pneumoniae, and Staphylococcus aureus strains, as well asclinical isolates of Salmonella enterica subsp. enterica, Klebsiella oxytoca, and uropathogenic E. coli. In addition, preformed biofilms ofE. coli C, Salmonella Typhimurium, K. pneumoniae, and Salmonella enterica exposed to treatments were removed by applying 12 mg/LNaClO, 0.1 mmol/L CuSO4, and 350 mmol/L H2O2 for 5 min. Klebsiella oxytoca and Staphylococcus aureus required a 5-fold increase in NaClOconcentration, and the E. coli clinical isolate remained unremovable unless treatments were applied on biofilms formed within 24 hinstead of 48 h. The application of treatments that last a few minutes using oxidizing compounds at low concentrations represents aninteresting disinfection strategy against pathogens associated with medical and industrial settings.