Abstract
We investigated the anti-Campylobacter activity of pinocembrin and its mechanism of action, as well as Campylobacter responses to pinocembrin treatment at the genetic and phenotypic levels, using C. jejuni NCTC 11168 and a multidrug efflux system repressor mutant (11168ΔcmeR). At its minimal inhibitory concentration, pinocembrin significantly increased cell membrane permeability of Campylobacter. Interestingly, at sub-inhibitory concentrations, pinocembrin did not significantly alter membrane functionality and it increased bacterial fitness. Treatment with pinocembrin evoked decreased expression of ribosomal proteins and down-regulation of several NADH dehydrogenase I chain subunits and proteins involved in iron uptake. This suggests altered protein production and redox cycle and iron metabolism. Interestingly, the chelation of Fe ions during the treatment with pinocembrin increased C. jejuni survival, although there was no increase in the formation of reactive oxygen species. Pre-treatment of C. jejuni with sub-inhibitory concentrations of pinocembrin for 2 h resulted in a 1 log decrease in C. jejuni colony forming units in mice liver at 8 days post-infection, compared to untreated C. jejuni. These findings suggest that pinocembrin modulates the metabolic activity of C. jejuni and that pre-treatment of C. jejuni with pinocembrin influences its virulence potential in mice. This anti-Campylobacter potential of pinocembrin warrants further investigation.
Highlights
Campylobacteriosis was the most frequently reported zoonotic disease in humans in Europe over last decade [1]
To evaluate the anti-Campylobacter activity of pinocembrin and the role of active efflux in Campylobacter resistance against pinocembrin, we determined the minimal inhibitory concentrations (MICs) for the wild-type C. jejuni NCTC 11168 and the three knockout mutants of C. jejuni NCTC 11168, with the defective efflux transporter genes cmeB and cmeF and transcriptional repressor cmeR
The antimicrobial activity of pinocembrin was moderate against C. jejuni NCTC 11168 and weaker compared to the antibiotics ciprofloxacin (MIC 0.062 μg/mL) and erythromycin (MIC 0.250 μg/mL), with a MIC of 64 μg/mL
Summary
Campylobacteriosis was the most frequently reported zoonotic disease in humans in Europe over last decade [1]. The European Centre for Disease Control has reported increased frequencies of antibiotic-resistant pathogenic bacteria and it is actively encouraging alternative strategies to control Campylobacter contamination and to combat infections without further increases in bacterial resistance [3]. Alternative approaches for prevention of Campylobacter contamination have been focused on the use of antimicrobials of natural origins. One such product is the 5,7-dihydroxyflavanone, pinocembrin, which is a major flavonoid that is used as a multifunctional active compound in the pharmaceutical industry [4,5,6]. Pinocembrin is found in a wide range of different plant species and is considered to be part of a normal healthy diet. Its potential to inhibit Campylobacter has not been tested to date
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
