Abstract

PORCEL DE FERNANDEZ, Norma Dolores; URUENA, Raquel; GAUDIOSO DE ALLORI, Maria Cristina  and  DE CASTILLO, Marta Elena Cecilia. Bactericidal activity of sodium hypochlorite against biofilm-producing Staphylococcus cohnii in a factory. Acta bioquím. clín. latinoam. [online]. 2013, vol.47, n.4, pp.693-700. ISSN 0325-2957.

Persistence of bacteria in industrial equipment is favoured by biofilm formation. Sodium hypochlorite (NaClO) is routinely used as a disinfectant. The objective of the current study was to determine the inhibitory effect of NaClO on biofilm-producing and non-biofilm-producing S. cohnii strains, isolated from equipment in a fresh pasta factory in Tucuman, Argentina. The following parameters were assayed: production of biofilm, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and NaClO death curves for both biofilm-producing and non-biofilm-producing S. cohnii strains. Four of the eight isolated Gram-positive cocci corresponded to S. cohnii. MIC and MBC values for biofilm-producing and non-biofilm-producing S. cohnii strains were between 0.05 and 0.2 g/dL. A bactericidal effect of 0.2 and 0.4% NaClO for 1 h was established with the death curve, showing a decrease in cfu of ≥4 log units. Biofilm production after 18 h for untreated strains gave an OD of 0.12, whereas the OD of treated strains was 0.07. The use of broad spectrum disinfectants is important, because elimination of bacteria helps prevent their propagation and avoid the formation of biofilms.

Keywords : Staphylococcus cohnii; Biofilms; Sodium hypochlorite; Antimicrobial activity.

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