title: Staphylococcal biofilm formation as affected by type acidulant.
abstract: Staphylococcal growth and biofilm formation in culture medium where pH was lowered with weak organic (acetic and lactic) or strong inorganic (hydrochloric) acids were studied. The effects were evaluated by biomass measurements, cell-surface hydrophobicity, scanning electron microscopy (SEM), and confocal laser scanning microscopy (CLSM). The results demonstrated that the inhibition was related to type of acidulant and pH value. At pH 5.0, the antibacterial effect was more pronounced in the presence of acetic acid (58-60% growth reduction) compared with that in the presence of lactic (7-16% growth reduction) and hydrochloric acids (23-24% reduction). The biofilm biomass of Staphylococcus aureus and Staphylococcus epidermidis was reduced by 92, 85, 63, and 93, 87, 81% after exposition to acetic, lactic, and hydrochloric acids, respectively. Increasing the pH from 5.0 to 6.0 resulted in a noticeable reduction in the effectiveness of acids. A minor cells hydrophobic character was also documented. The SEM and CLSM revealed a poorly structured and thinner biofilm compared with the dense and multilayered control. Acidic environment could have important implications for food-processing system to prevent bacterial colonization and control biofilm formation. The findings of this study lead to consider the rational use of the type of acid to achieve acidic environments.
authors: Dipartimento di Scienze del Farmaco e dei Prodotti per la Salute, Università di Messina, Messina, Italy.
authors: Antonia
authors: A
authors: Nostro
authors: Luigina
authors: L
authors: Cellini
authors: Giovanna
authors: G
authors: Ginestra
authors: Manuela
authors: M
authors: D'Arrigo
authors: Mara
authors: M
authors: di Giulio
authors: Andreana
authors: A
authors: Marino
authors: Anna Rita
authors: AR
authors: Blanco
authors: Angelo
authors: A
authors: Favaloro
authors: Giuseppe
authors: G
authors: Bisignano
mesh_terms: D019342:Acetic Acid / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D018441:Biofilms / Q000254:growth & development*; D006851:Hydrochloric Acid / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D019344:Lactic Acid / Q000494:pharmacology; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D013211:Staphylococcus aureus / Q000254:growth & development*; D013212:Staphylococcus epidermidis / Q000254:growth & development*
chemical_list: D000900:Anti-Bacterial Agents; D019344:Lactic Acid; D019342:Acetic Acid; D006851:Hydrochloric Acid
keywords: Biofilm; Staphylococcus aureus; Staphylococcus epidermidis; acidulant; pH