Grape Phenolic Extract Potentially Useful in the Control of Antibiotic Resistant Strains of <i>Campylobacter</i>

Abstract

In this work, a grape phenolic extract obtained by methanol extraction has been demonstrated to be effective in inhibiting the growth of different strains and species of Campylobacter, one of the most important bacterial foodborne pathogens causing gastroenteritis worldwide. Noteworthily, it was particularly effective against several strains presenting multiple antibiotic resistances. In all cases, the minimum inhibitory concentration (MIC) was lower than 300 mg GAE/L, being of 60 mg GAE/L for one of the most resistant strains (C. coli LP2), while the others were between 120 mg GAE/L and 180 mg GAE/L. The analytical study of the main phenolic compounds in the grape extract revealed that it was mainly constituted by catechins (85.7%) and phenolic acids (13.7%). However, experiments developed using pure standards demonstrate that phenolic acids (such as gallic, p-hidroxibenzoic, vanillic, and homovanillic acids) were the most active, provoking a Campylobacter growth decrease between 6.7 and 7.6 log, while epicatechin was the only catechin with activity as pure compound (1 log of growth decrease).

Selective antibacterial effect on Campylobacter of a winemaking waste extract (WWE) as a source of active phenolic compounds

“…Anthocyanins, phenolic acids and stilbenes were in minor proportion. Despite the effects of the fermentation and the mildest process used for phenolic extraction, the distributions in families of individual phenolic compounds were similar to those obtained from the GSE (Silvan et al, 2013) or grapes (Mingo et al, 2014). Also, in the WWE, t-resveratrol and t-piceid were found and quantified.…”

“…In addition to being the major phenolic compounds constituting the extract, there are several reports describing the antibacterial effect of catechins and proanthocyanidins against different bacteria (Nakayama, Shimatani, Ozawa, Shigemune, Tsugukuni, Tomiyama, et al, 2013;Reygaert, 2014). Moreover, we have previously observed some antibacterial effect of pure epicatechin on C. jejuni (Ganan et al, 2009;Mingo et al, 2014). The fractioning of a commercial grape seed extract active against Campylobacter also suggested that some catechins were involved in the antibacterial effect of the whole extract (Silvan et al, 2013), however it was difficult to associate the effect to a specific compound or family of compounds, because three of the four obtained fractions had antibacterial activity against Campylobacter.…”

“…Several researchers have described that the presence of water in the extraction solvent used for grape by-products extraction increases the permeability of cell tissues, improving the recovery of water soluble compounds (Fontana et al, 2013). Although higher yields have been obtained using methanol as unique solvent (Fontana et al, 2013;Mingo et al, 2014) these results indicate that the use of an economic and environmentallyfriendly solvent as ethanol can be enough to obtain an active WWE against Campylobacter. This is consequent with the fact that Campylobacter have proved to be more sensitive than others microorganisms to several phenolic compounds (Friedman, 2014).…”

Anti-Campylobacteractivity of resveratrol and an extract from waste Pinot noir grape skins and seeds, and resistance ofCamp. jejuniplanktonic and biofilm cells, mediated via the CmeABC efflux pump

“…The antibacterial activity of grape phenolics has been attributed to the antimicrobial effects on bacteriostatic actions through changes in cell morphology and DNA content (Paulo et al 2010). Additionally, resveratrol can be used to control Campylobacter and Arcobacter foodborne pathogens with antibacterial, antibiofilm and anti- QS potential activities, especially as inclusion complexes, which promote slower release of these compound within food and food products (Silv an et al 2013;Mingo et al 2014;Duarte et al 2015).…”

“…The by-products of plant processing for food represent a major disposal problem, although some of these might be promising sources of compounds with favourable technological or nutritional properties (Davidson et al 2013;Teixeira et al 2014;Xu et al 2016). For the control of Campylobacter contamination, the potential for efficient and safe application of antimicrobial phytochemicals obtained from agro-food by-products means that it is important to study such bioactivities in vitro and in vivo (Silv an et al 2013;Mingo et al 2014).…”