Whole-genome sequencing and genetic analysis reveal novel stress responses to individual constituents of essential oils in Escherichia coli

Chueca, B. ; Renzoni, A. ; Berdejo, D. (Universidad de Zaragoza) ; Pagán, R. (Universidad de Zaragoza) ; Kelley, W.L. ; García-Gonzalo, D. (Universidad de Zaragoza)

Resumen: Food preservation by the use of essential oils (EOs) is being extensively studied because of the antimicrobial properties of their individual constituents (ICs). Three resistant mutants (termed CAR, CIT, and LIM) of Escherichia coli MG1655 were selected by subculturing with the ICs carvacrol, citral, and (+)-limonene oxide, respectively. These derivative strains showed increased MIC values of ICs and concomitantly enhanced resistance to various antibiotics (ampicillin, trimethoprim, chloramphenicol, tetracycline, kanamycin, novobiocin, norfloxacin, cephalexin, and nalidixic acid) compared to those for the parental strain (wild type [WT]). Whole-genome sequencing (WGS) of these hyperresistant strains permitted the identification of single nucleotide polymorphisms (SNPs) and deletions in comparison to the WT. In order to analyze the contribution of these mutations to the increased antimicrobial resistance detected in hyperresistant strains, derivative strains were constructed by allelic reversion. A role of the SoxR D137Y missense mutation in CAR was confirmed by growth in the presence of some ICs and antibiotics and by its tolerance to ICs but not to lethal heat treatments. In CIT, increased resistance relied on contributions by several detected SNPs, resulting in a frameshift in MarR and an in-frame GyrB ¿G157 mutation. Finally, both the insertion resulting in an AcrR frameshift and large chromosomal deletions found in LIM were correlated with the hyperresistant phenotype of this strain. The nature of the obtained mutants suggests intriguing links to cellular defense mechanisms previously implicated in antibiotic resistance.

Idioma: Inglés

DOI: 10.1128/AEM.02538-17

Año: 2018

Publicado en: Applied and Environmental Microbiology 84, 7 (2018), e02538-17
ISSN: 0099-2240

Factor impacto JCR: 4.077 (2018)

Categ. JCR: BIOTECHNOLOGY & APPLIED MICROBIOLOGY rank: 33 / 162 = 0.204 (2018) - Q1 - T1
Categ. JCR: MICROBIOLOGY rank: 38 / 133 = 0.286 (2018) - Q2 - T1

Factor impacto SCIMAGO: 1.663 - Applied Microbiology and Biotechnology (Q1) - Food Science (Q1) - Ecology (Q1) - Biotechnology (Q1)

Financiación: info:eu-repo/grantAgreement/ES/MINECO/AGL2012-32165
Financiación: info:eu-repo/grantAgreement/ES/MINECO/AGL2015-69565-P

Tipo y forma: Artículo (Versión definitiva)

Área (Departamento): Área Tecnología de Alimentos (Dpto. Produc.Animal Cienc.Ali.)