Ecology of antimicrobial resistance: humans, animals, food and environment

Abstract

Antimicrobial resistance is a major health problem. After decades of research, numerous difficulties in tacklingresistance have emerged, from the paucity of new antimicrobials to the inefficient contingency plans to reduce the use ofantimicrobials; consequently, resistance to these drugs is out of control. Today we know that bacteria from the environmentare often at the very origin of the acquired resistance determinants found in hospitals worldwide. Here we define the geneticcomponents that flow from the environment to pathogenic bacteria and thereby confer a quantum increase in resistance levels,as resistance units (RU). Environmental bacteria as well as microbiomes from humans, animals, and food represent aninfinite reservoir of RU, which are based on genes that have had, or not, a resistance function in their original bacterial hosts.This brief review presents our current knowledge of antimicrobial resistance and its consequences, with special focus on theimportance of an ecologic perspective of antimicrobial resistance. This discipline encompasses the study of the relationshipsof entities and events in the framework of curing and preventing disease, a definition that takes into account both microbialecology and antimicrobial resistance. Understanding the flux of RU throughout the diverse ecosystems is crucial to assess,prevent and eventually predict emerging scaffolds before they colonize health institutions. Collaborative horizontal researchscenarios should be envisaged and involve all actors working with humans, animals, food and the environment. [IntMicrobiol 2012; 15(3):101-109]