Antimicrobial Resistance in Bacteria from Animals and the Environment

Antimicrobial resistance in bacteria has become a major public health issue during the past decade. Antimicrobial agents are indispensable in the control of bacterial infections, not only in humans, but also in animals and plants. Every use of an antimicrobial agent selects for bacteria with elevated minimal inhibitory concentrations. Under the selective pressure imposed by the use of antimicrobial agents, bacteria which possess resistance mechanisms can multiply and expand at the expense of the bacteria that are inhibited by the respective antimicrobial agents. Moreover, bacteria can pass resistance genes to other bacteria through horizontal gene transfer and thereby contribute to the dissemination of resistance genes within bacterial populations of different ecosystems. In polymicrobial environments, such horizontal gene transfer processes may involve donors and recipients that belong to different bacterial species and genera. These basic facts apply not only to bacteria of human origin, but also to those of animal and environmental origin – a situation that is reflected by the “One Health” concept. Antimicrobial resistance in bacteria is a highly multifaceted topic at the interface of human, animal and plant health, food hygiene and environmental science. Besides the analysis of resistance genes and resistance-mediating mutations, the dissemination of resistance properties and the analysis of mobile genetic elements that play a role in the spreading of resistance gens across species and genus boundaries, numerous other aspects play an important role when dealing with antimicrobial resistance. These include among others (i) pharmacological aspects with regard to the application of antimicrobial agents, (ii) methodological aspects with regard to the correct performance of antimicrobial susceptibility testing, (iii) antimicrobial resistance monitoring programmes, (iv) antimicrobial stewardship, (v) animal models, (vi) antimicrobial resistance in bacteria from specific sources, such as wildlife, aquaculture, food-producing animals, companion animals and the environment, and (vii) alternative, non-antimicrobial strategies to control bacterial infections. All these aspects were addressed during the 5th Symposium on Antimicrobial Resistance in Animals and the Environment (ARAE 2013), which was held from June 30 to July 3, 2013 in Ghent, Belgium. The forum provided an important venue for networking between and discussion among scientists engaged in understanding different aspects of the antibiotic resistance problem, and in finding ways to mitigate the impact of resistance. This Special Issue of Veterinary Microbiology captures the flavor and quality of the wide-ranging presentations made at the Symposium, and will be a useful single source resource for workers in this field. This symposium, which is held in 2-years intervals since 2005, comprised one keynote lecture and another six invited lectures given by experts in the specific fields. In his keynote lecture, John F. Prescott summarized the situation with regard to antimicrobial agents and antimicrobial resistance during the past 60 years. He illustrated that changes in the practice of how we use antimicrobial agents are unavoidable and that Good Stewardship Practice should be adopted by everyone involved in antimicrobial use and application. Despite increasing percentages of resistant bacteria and decreasing numbers of new antimicrobial agents – especially for use in veterinary medicine –, he also emphasized the availability of new technologies, such as whole genome sequencing, which may be used for the identification of new bacterial targets that serve for the development of future antimicrobial agents for specific bacterial pathogens and disease conditions (Prescott, 2014). Moreover, 42 oral presentations (selected from the submissions) and 83 poster presentations completed the programme of this symposium. This Special Issue of Veterinary Microbiology comprises a collection of review articles, original research papers and short communications from contributions presented at the ARAE 2013 symposium. The following paragraphs provide a short summary of the different studies compiled in this special issue based on their assignment to topics of the symposium.