Abstract
Campylobacter is the leading cause of bacterial foodborne gastroenteritis worldwide. Infections by Campylobacter in humans are generally caused by consuming contaminated foods of animal origin, with poultry, especially chicken, being the main reservoir. The high prevalence of Campylobacter in chicken carcasses and the growing resistance to the most widely used antibiotics has driven EFSA to propose a regulation (2017/1495) containing new microbiological criteria to regulate the presence of Campylobacter in broiler carcasses. In this context, there has been an increase in the number of research aimed at the search for new tools to reduce Campylobacter incidence in chicken meat. The objective of the present work was to evaluate the antibacterial activity of two olive leaf extracts (A y B) against eleven Campylobacter spp. strains (C. jejuni y C. coli) isolated from chicken food chain. Results showed that all Campylobacter strains had resistance to at least one of the eight antibiotics evaluated, and 46% of them were antibiotic multi-resistant. HPLC analysis showed that hydroxytyrosol and oleuropein were the major phenolic compounds in extracts A and B, respectively. Extract A showed a significant antibacterial activity against all Campylobacter strains tested in the present work. The use of a pure standard of hydroxytyrosol confirmed the contribution of this compound to the antibacterial effect of extract A. These results suggest that olive leaves could be used as a source of bioactive compounds to obtain extracts with antibacterial activity against Campylobacter spp potentially applicable to reduce the presence of Campylobacter in chicken carcasses.
Supplementary Materials
The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/Foods2021-10951/s1.
Author Contributions
Conceptualization, A.J.M.-R. and J.M.S.; methodology, A.J.M.-R., J.M.S., M.P. and M.V.; software, A.J.M.-R. and J.M.S.; validation, A.J.M.-R. and J.M.S.; formal analysis, A.G.-D., A.J.M.-R., E.G.-H. and J.M.S.; investigation, A.G.-D., A.J.M.-R., E.G.-H., J.M.S., M.P., M.V., S.D. and R.C.; resources, A.J.M.-R. and J.M.S.; data curation, A.J.M.-R. and J.M.S.; writing—original draft preparation, A.J.M.-R. and J.M.S.; writing—review and editing, A.J.M.-R. and J.M.S.; visualization, A.J.M.-R. and J.M.S.; supervision, A.J.M.-R. and J.M.S.; project administration, A.J.M.-R.; funding acquisition, A.J.M.-R. All authors have read and agreed to the published version of the manuscript.
Funding
This research was funded by MINECO (Spain), Project HELIFOOD (AGL2017-89566-R).
Institutional Review Board Statement
Not applicable.
Informed Consent Statement
Not applicable.
Data Availability Statement
The data presented in this study are available in this manuscript.
Acknowledgments
Esperanza Guerrero-Hurtado thanks Consejería de Educación e Investigación from Comunidad de Madrid for the financial support of contract IND2019/BIO-17238.
Conflicts of Interest
The authors declare no conflict of interest.
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