title: Biocide tolerance, phenotypic and molecular response of lactic acid bacteria isolated from naturally-fermented Aloreña table to different physico-chemical stresses.
abstract: Lactic acid bacteria (LAB) isolated throughout the fermentation process of Aloreña table olives were found to be resistant at least to three antibiotics (Casado Muñoz et al., 2014); however, most were sensitive to the biocides tested in this study (with minimum inhibitory concentrations [MIC] below the epidemiological cut-off values). 2-15% of the isolates were found to be biocide resistant: Leuconostoc Pseudomesenteroides, which were resistant to hexachlorophene, and Lactobacillus pentosus to cetrimide and hexadecylpiridinium. We analyzed the effect of different physico-chemical stresses, including antimicrobials, on the phenotypic and genotypic responses of LAB, providing new insights on how they become resistant in a changing environment. Results indicated that similar phenotypic responses were obtained under three stress conditions: antimicrobials, chemicals and UV light. Susceptibility patterns to antibiotics changed: increasing MICs for ampicillin, chloramphenicol, ciprofloxacin, teicoplanin and tetracycline, and decreasing the MICs for clindamycin, erythromycin, streptomycin and trimethoprim in most strains. Statistically, cross resistance between different antibiotics was detected in all stress conditions. However, expression profiles of selected genes involved in stress/resistance response (rpsL, recA, uvrB and srtA) differed depending on the stress parameter, LAB species and strain, and the target gene. We conclude that, despite the uniform phenotypic response to stresses, the repertoire of induced and repressed genes differs. So, a search for a target to improve stress tolerance of LAB, especially those of importance as starter/protective cultures or probiotics, may depend on the individual screening of each strain, even though we could predict the antibiotic phenotypic response to all stresses.
authors.affiliation: Área de Microbiología, Departamento de Ciencias de la Salud, Facultad de Ciencias Experimentales, Universidad de Jaén, 23071, Jaén, Spain.
authors.forename: María Del Carmen
authors.initials: Mdel C
authors.lastname: Casado Muñoz
authors.affiliation: Área de Microbiología, Departamento de Ciencias de la Salud, Facultad de Ciencias Experimentales, Universidad de Jaén, 23071, Jaén, Spain.
authors.forename: Nabil
authors.initials: N
authors.lastname: Benomar
authors.affiliation: Área de Microbiología, Departamento de Ciencias de la Salud, Facultad de Ciencias Experimentales, Universidad de Jaén, 23071, Jaén, Spain.
authors.forename: Leyre
authors.initials: L
authors.lastname: Lavilla Lerma
authors.affiliation: Department of Civil and Environmental Engineering, University of Strathclyde, Glasgow, Scotland, United Kingdom.
authors.forename: Charles W
authors.initials: CW
authors.lastname: Knapp
authors.affiliation: Área de Microbiología, Departamento de Ciencias de la Salud, Facultad de Ciencias Experimentales, Universidad de Jaén, 23071, Jaén, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Gálvez
authors.affiliation: Área de Microbiología, Departamento de Ciencias de la Salud, Facultad de Ciencias Experimentales, Universidad de Jaén, 23071, Jaén, Spain. Electronic address: hikmate@ujaen.es.
authors.forename: Hikmate
authors.initials: H
authors.lastname: Abriouel
mesh_terms: D019881:Aminoacyltransferases / Q000235:genetics; D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000494:pharmacology; D002594:Cetylpyridinium / Q000494:pharmacology; D003546:Cysteine Endopeptidases / Q000235:genetics; D004202:Disinfectants / Q000494:pharmacology*; D005285:Fermentation; D005516:Food Microbiology; D006582:Hexachlorophene / Q000494:pharmacology; D007777:Lactobacillaceae / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification / Q000528:radiation effects; D007778:Lactobacillus / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D007934:Leuconostoc / Q000187:drug effects / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D031658:Olea / Q000382:microbiology*; D010641:Phenotype; D019936:Probiotics / Q000302:isolation & purification / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D011938:Rec A Recombinases / Q000235:genetics; D013312:Stress, Physiological / Q000235:genetics
chemical_list: D000891:Anti-Infective Agents, Local; D001426:Bacterial Proteins; D002593:Cetrimonium Compounds; D004202:Disinfectants; D002594:Cetylpyridinium; D019881:Aminoacyltransferases; C120542:sortase A; D011938:Rec A Recombinases; D003546:Cysteine Endopeptidases; D006582:Hexachlorophene; D000077286:Cetrimonium
keywords: Antibiotics; Biocides; Gene expression; Lactobacillus pentosus; Leuconostoc pseudomesenteroides; Quantitative PCR; Stress