Antiadhesion activity of juniper (Juniperus communis L.) preparations against Campylobacter jejuni evaluated with PCR‐based methods

Abstract

The food-borne pathogen Campylobacter jejuni can cause bacterial gastrointestinal infections. Biofilm formation amplifies the risk of human infection by improving survival and persistence of C. jejuni in food processing environments and its transmission through the food chain. We aimed to control C. jejuni using an alternative strategy of low doses of Juniperus communis fruit preparations to target bacterial adhesion properties in the first step of biofilm formation. First, we defined the anti-Campylobacter activity of a juniper fruit crude extract and its fractionated biflavonoids, flavone glycosides, and purified amentoflavone, of juniper fruit essential oil and of juniper fruit postdistillation waste material extract. For accurate quantification of adherent C. jejuni, we optimised digital Polymerase Chain Reaction (PCR) and quantitative real-time PCR for construction of standard curves and quantification. We show for the first time that juniper fruit formulations can effectively inhibit adhesion of C. jejuni to polystyrene. Furthermore, ≥94% of the antiadhesion activity of juniper fruit crude extract and juniper fruit essential oil remained under food-related conditions: modified culture medium with glucose, or a stainless steel surface, or mixed co-cultures of C. jejuni and Listeria monocytogenes. This study indicates that addition of juniper fruit formulations can control growth and adhesion of C. jejuni and thus limit food chain transmission of campylobacters.

Modulation of Campylobacter jejuni Motility, Adhesion to Polystyrene Surfaces, and Invasion of INT407 Cells by Quorum-Sensing Inhibition

“…The juniper essential oil (EO1) had the strongest effect here, as it reduced C. jejuni adhesion by 1.89-log units (approximately 99%). The same strong anti-adhesion effect of juniper essential oil (99% reduction) was also demonstrated by Klančnik et al [44] using qPCR quantification of C. jejuni adhesion.…”

Bioactivity of Juniperus communis essential oil and post-distillation waste: Assessment of selective toxicity against food contaminants

“…The first step in this process is attachment to host intestinal cells, thus the search for natural products with anti-adhesive properties is encouraged [23,40]. The ability of J. communis products to inhibit adhesion of Campylobacter jejuni to polystyrene has been recently reported [41]. Moreover, in the same study, anti-adhesive properties were even increased in cocultured C. jejuni and L. monocytogenes.…”

Anti-adhesion activity of phytochemicals to prevent Campylobacter jejuni biofilm formation on abiotic surfaces

“…can adhere to inert surfaces of different materials used in different industries, such as stainless steel, glass fibre, glass beads and coverslips, nitrocellulose membranes, and various plastics (Sulaeman et al 2012;Teh et al 2014;Š ikić Pogačar et al 2015;Klančnik et al 2017b). Indeed, the most commonly used model for determination of anti-adhesion activities of phytochemicals is polystyrene microtiter plates, followed by stainless steel coupons of diverse surface roughness, and glass surfaces (Bezek et al 2016;Klančnik et al 2017bKlančnik et al , 2018bWagle et al 2019). It is important to include abiotic surfaces with different degrees of roughness, to thus present different in vivo conditions of surface irregularities, which have been shown to provide the cell shelter that is relevant for biofilm formation in food processing facilities (Bohinc et al 2014).…”