A brief multi-disciplinary review on antimicrobial resistance in medicine and its linkage to the global environmental microbiota

Abstract

The discovery and introduction of antimicrobial agents to clinical medicine was one of the greatest medical triumphs of the 20th century that revolutionized the treatment of bacterial infections. However, the gradual emergence of populations of antimicrobial-resistant pathogenic bacteria resulting from use, misuse, and abuse of antimicrobials has today become a major global health concern. Antimicrobial resistance (AMR) genes have been suggested to originate from environmental bacteria, as clinically relevant resistance genes have been detected on the chromosome of environmental bacteria. As only a few new antimicrobials have been developed in the last decade, the further evolution of resistance poses a serious threat to public health. Urgent measures are required not only to minimize the use of antimicrobials for prophylactic and therapeutic purposes but also to look for alternative strategies for the control of bacterial infections. This review examines the global picture of antimicrobial resistance, factors that favor its spread, strategies, and limitations for its control and the need for continuous training of all stake-holders i.e., medical, veterinary, public health, and other relevant professionals as well as human consumers, in the appropriate use of antimicrobial drugs.

Keywords: antimicrobial resistance; environment; human and veterinary medicine; resistance genes; soil; wastewater.

Figure 1

Schematic representation of the complexity of the potential bacterial genetic web of communication between the various microbiotas that are impacted by the use of antibiotics in a wide context. The reservoirs where antimicrobials are applied are also suggested as “hot spots” for horizontal gene transfer. The potentially most important genetic links between the microbiotas of the various reservoirs are showed by arrows. Thick arrows show major selective pressures for selection of antibiotic resistance genes, thin arrows show the significant directions of gene flow. Future research may document unique arrows that must be integrated in the web drawn.

Figure 2

The change in number of antimicrobial resistance related published research papers in different subdisciplines and covering different environments. The data for the graphs were obtained by searching the ISI web of science for publications with titles matching the query terms (antibioti^* OR antimicro^*) AND resistan^* AND the following specific terms: Hospital, (hospital^* OR patient^* OR clinic^*); Animal, (animal^* OR veterinary^* OR livestock^* OR pig^* OR cow^* OR chicken^* OR poultry); Wastewater, (wastewate^* OR sewage); Natural water, (wate^* OR lake OR river OR ocean OR sea); Soil, (soil^* OR sediment^* OR rhizosphere^*) (Source: http://apps.isiknowledge.com/). The search was performed on 06/03/2013.