Influence of the Type of Diet on the Incidence of Pathogenic Factors and Antibiotic Resistance in Enterococci Isolated from Faeces in Mice.

Beatriz Sánchez,Ana M Martínez-Rodríguez,Antonio Gálvez,Isabel Prieto,Marina Hidalgo,Magdalena Martínez-Cañamero,Antonio Cobo

doi:10.3390/ijms20174290

Beatriz Sánchez, Ana M Martínez-Rodríguez + Show 5 more

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https://doi.org/10.3390/ijms20174290

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Abstract

A comparative study on potential risks was carried out in a collection of 50 enterococci isolated from faeces of mice fed a standard or a high-fat diet enriched with extra virgin olive oil, refined olive oil or butter, at the beginning, after six weeks and after twelve weeks of experiments. Strains were biochemically assessed and genetically characterized. E. faecalis and E. casseliflavus were the most frequently isolated species in any diet and time points. Apart from the fact of not having isolated any strain from the virgin olive oil group during the last balance, we found statistically significant differences among the diets in the percentage of antibiotic resistance and in the presence of the enterococcal surface protein gene (esp), as well as a tendency for the presence of the tyrosine decarboxylase gene (tdc) to increase over time in the group of isolates from the standard diet. When the resistance of the strains to virgin or refined olive oil was studied, only the group of enterococci from high fat diets showed a significantly higher percentage of resistance to refined olive oil , while both types of oil equally inhibited those isolated from the standard diet .

Highlights

The intestinal microbial diversity will be determined by the interactions among the organisms that compose it, the genetics of the host and the diets applied [1]
While studying the dissimilar effect of fats with different degrees of saturation, we have previously reported several studies comparing the influence of virgin olive oil (EVOO) and butter (BT) on the intestinal microbiota of mice, both using genotyping methods [4] and massive sequencing [5]
A previous collection of bacterial strains obtained from faeces of mice fed four different diets (SD, BT, EVOO and refined olive oil (ROO)) over a twelve-week period was screened for enterococcal phenotypic characteristics

Summary

Introduction

The intestinal microbial diversity will be determined by the interactions among the organisms that compose it, the genetics of the host and the diets applied [1]. While studying the dissimilar effect of fats with different degrees of saturation, we have previously reported several studies comparing the influence of virgin olive oil (EVOO) and butter (BT) on the intestinal microbiota of mice, both using genotyping methods [4] and massive sequencing [5] In these works, we presented evidence supporting a link between specific diets, physiological parameters and some bacterial taxa. Intestinal microorganisms will deal with the capacity of self-regulation of the system, the available food and the competition for resources, and will have to defend themselves against chemical products or aggressive proteins, which will lead to many of these bacterial groups to develop strategies and defence mechanisms Among these mechanisms, we can find the expression of virulence factors or antibiotic resistance. These defensive weapons will inescapably affect the host, potentially causing serious clinical consequences

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