109395 20250319143307.0 doi 10.1016/j.foodres.2021.110403 sideral 125445 ART-2021-125445 eng Berdejo, Daniel Universidad de Zaragoza (orcid)0000-0001-5053-8309 Emerging mutant populations of Listeria monocytogenes EGD-e under selective pressure of Thymbra capitata essential oil question its use in food preservation 2021 Access copy available to the general public Unrestricted Due to their excellent antimicrobial properties, essential oils (EO) have been proposed as potential preservatives for certain kinds of foods, such as dairy products. However, the occurrence of pathogenic populations that are resistant to EOs could pose a health risk. This report seeks to assess the emergence of resistant populations in Listeria monocytogenes EGD-e growth at 37 °C under selective pressure of Thymbra capitata EO (TCO), to characterise their resistance in laboratory media, and to identify their genotypic changes, as well as to evaluate the resistance in skimmed milk. TCO cyclic treatment allowed the isolation of two L. monocytogenes EGD-e resistant strains against the EO: LmSTCO by sublethal doses (75 µL/L TCO) and LmLTCO by lethal doses (300 µL/L TCO) after 20 and 30 cycles, respectively. Both strains displayed an increase of the minimum inhibitory and bactericidal concentration against TCO and a higher survival rate after lethal treatments than the wild-type strain (LmWT). Growth kinetics revealed a better adaptation of LmSTCO in presence of TCO, while LmLTCO grew more slowly compared to LmWT, even in the absence of the antimicrobial. Moreover, a slight increase in cross-resistance to antibiotics was observed: LmSTCO to β-lactams and LmLTCO to a series of broad-spectrum antibiotics. The genomic study revealed one sole nucleotide change in LmSTCO located in plsC gene codifying an enzyme involved in the production of phosphatidic acid, a precursor in cell membrane synthesis. Five genetic variations were found in LmLTCO: among them, the deletion of an ATP-synthesis system involved in slowing bacterial growth. Inhibition and inactivation assays in skimmed milk confirmed the increased resistance of both strains, thereby indicating a safety risk in case these strains emerge in the food chain. These results strongly suggest that the occurrence of such resistances should be taken into account in order to ensure the efficacy of natural antimicrobials in the design of food preservation strategies. info:eu-repo/grantAgreement/ES/AEI-ESF-DGA/PGC2018-093789-B-I00 info:eu-repo/semantics/openAccess by http://creativecommons.org/licenses/by/3.0/es/ 7.425 2021 FOOD SCIENCE & TECHNOLOGY 13 / 144 = 0.09 2021 Q1 T1 1.248 2021 Food Science 2021 Q1 11.1 2021 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Pagán, Elisa Universidad de Zaragoza (orcid)0000-0003-3752-4660 Merino, Natalia Universidad de Zaragoza (orcid)0000-0003-4774-0973 García-Gonzalo, Diego Universidad de Zaragoza (orcid)0000-0002-7629-8101 Pagán, Rafael Universidad de Zaragoza (orcid)0000-0002-0238-6328 2008 780 Universidad de Zaragoza Dpto. Produc.Animal Cienc.Ali. Área Tecnología de Alimentos 145 (2021), 110403 [9 pp.] Food res. int. Food Research International 0963-9969 1326997 http://zaguan.unizar.es/record/109395/files/texto_completo.pdf Versión publicada 2577707 http://zaguan.unizar.es/record/109395/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:109395 articulos driver 2025-03-19-14:32:14 ARTICLE