Interaction of Salmonella sp. and essential oils: bactericidal activity and adaptation capacity

Resumo

Bacteria of the genus Salmonella, responsible for many foodborne disease outbreaks, are capable of forming biofilms on various surfaces in the food industry. The constant exposure of these bacteria to sublethal concentrations of sanitizers has made them tolerant to several of them. Seeking alternatives to control of bacterial biofilms and adaptation under sublethal exposure, this study tested the antimicrobial activity of Thymus vulgaris (thyme) and Origanum vulgare (oregano) essential oils (EOs) and their major compounds, thymol and carvacrol, against of Salmonella enterica serovars Enteritidis and Typhimurium. Carvacrol 0.25% (v/v) was the most efficient antimicrobial agent against planktonic cells of S. Enteritidis and biofilm were more susceptible to oregano EO at 2.0% (v/v). Differently, S. Typhimurium planktonic was inhibited at 0.25% (v/v) of thyme EO and biofilm was more susceptible to carvacrol (2.5% v/v). Adaptation of S. Enteritidis and Typhimurium was observed on all tests (p < 0.05). This study confirms the potential of EOs and its major compounds as alternative sanitizers in the food industry against pathogenic bacteria such as Salmonella spp. and of possible adaptation due to sublethal exposure.