The Antimicrobial and Antibiofilm Activity of Oregano Essential Oil against Enterococcus faecalis and Its Application in Chicken Breast

Abstract

Oregano essential oil (OEO) possesses anti-inflammatory, antioxidant, and cancer-suppressive properties. Enterococcus faecalis is a foodborne opportunistic pathogen that can be found in nature and the food processing industry. The goal of this investigation was to explore the antimicrobial action and mechanism of OEO against E. faecalis, inactivation action of OEO on E. faecalis in mature biofilms, and its application in chicken breast. The minimum inhibitory concentration (MIC) of OEO against E. faecalis strains (ATCC 29212 and nine isolates) ranged from 0.25 to 0.50 μL/mL. OEO therapy reduced intracellular adenosine triphosphate (ATP) levels, caused cell membrane hyperpolarization, increased the intracellular reactive oxygen species (ROS), and elevated extracellular malondialdehyde (MDA) concentrations. Furthermore, OEO treatment diminished cell membrane integrity and caused morphological alterations in the cells. In biofilms on stainless-steel, OEO showed effective inactivation activity against E. faecalis. OEO reduced the number of viable cells, cell viability and exopolysaccharides in the biofilm, as well as destroying its structure. Application of OEO on chicken breast results in a considerable reduction in E. faecalis counts and pH values, in comparison to control samples. These findings suggest that OEO could be utilized as a natural antibacterial preservative and could effectively control E. faecalis in food manufacturing.

Effect of Vapor-Phase Oregano Essential Oil on Resistant Candida Species Biofilms: Mechanisms of Action

“…The high incidence of resistant Candida species and the associated negative consequences and therapeutic limitations make it crucial to develop effective, inexpensive, and nontoxic alternative treatments. In this sense, OEO has demonstrated good fungicidal and bactericidal activities against different pathogens ( 28 – 30 ). Recent studies also showed that the volatile part of the EO (VP-OEO) has interesting antimicrobial activity ( 31 – 33 ).…”

In Vitro Evaluation of Phytobiotic Mixture Antibacterial Potential against Enterococcus spp. Strains Isolated from Broiler Chicken

“…As already emphasized, there are few studies analyzing the antibacterial effect of phytobiotic products on the most common Enterococcus strains in broilers (reference strains and strains occurring in industrial breeding) [45,46]. The problem of comparing results probably stems from the fact that the mixture of phytobiotics used in the experiment has a unique composition, not found in any other preparation.…”

Biofilm Formation Capacity and Presence of Virulence Determinants among Enterococcus Species from Milk and Raw Milk Cheeses

“…In recent years, biofilm has become a worldwide public health. According to the literature data, it is worth noting that many Enterococcus strains can build biofilms on food contact surfaces [ 18 ]. In the current study, 73.5% isolates from raw milk and 47.2% isolates from cheeses exhibited great biofilm-forming ability.…”

“…The presence of biofilms on work surfaces may result in the contamination of food products with both spoilage and pathogenic microorganisms [ 17 ]. Many Enterococcus strains can form biofilms on food contact surfaces, which improve bacteria’s resistance to environmental stress [ 18 ]. It is worth noting that the modernity of the equipment used in the dairy industry and, consequently, the long-lasting production cycles and the associated extensive surfaces of materials in direct contact with foods, provide favorable conditions for the unhindered formation and development of a bacterial biofilm.…”