Antibiotic resistant enterobacteriaceae and the intestinal microbiota: the hidden side of the iceberg

Abstract

The intestinal microbiota (IM) also named “commensal flora” is the most original metabolic organ in our body, as formed by several hundred different bacterial species with a specific composition depending on its host. IM plays a key role in our immunity, in the inflammatory diseases of the gastro-intestinal tract as well as in the production of vitamins. Yet, IM is a metabolic organ that we alter following each antibiotic intake. Whatever are its family, its dosage, its duration, and even its route of administration, every antibiotic has an effect on the IM. IM is a substantial reservoir for resistant bacteria and genes for resistance. A major side-effect of the antibiotics is the selection of resistant bacteria in the IM. In this review, we will focus on betalactams and fluoroquinolones, two major antibiotics families commonly used in the intensive care units and possibly responsible for clinically relevant damage.