001. Felipe C. Cabello, Henry P. Godfrey. Department of Microbiology and Immunology, New York Medical College, Valhalla, New York, USA. Even therapeutic antimicrobial use in animal husbandry may generate environmental hazards to human health. Environmental Microbiology, 2016, Vol. 18 (2), Page: 311 – 313.

      The potential negative impact for human health of veterinary use of antimicrobials in prophylaxis, metaphylaxis and growth promotion in animal husbandry was first established in the 1960s and 1970s. Determination of the molecular structure of antimicrobial resistance plasmids at that time explained the ability of antimicrobial resistance genes to disseminate among bacterial populations and elucidated the reasons for the negative effects of antimicrobials used in food animals for human health. In this issue of Environmental Microbiology, Liu et al. (2016) show that even therapeutic use of antimicrobials in dairy calves has an appreciable environmental microbiological footprint. We discuss the negative implications of this footprint for human health and the possibility they may lead to calls for increased regulation of veterinary antimicrobial use in terrestrial and aquatic environments.

002. Felipe C Cabello, Henry P Godfrey, Alejandro H Buschmann, Humberto J Dölz. Department of Microbiology and Immunology, New York Medical College, Valhalla, New York, NY 10595-1524, USA. Aquaculture as yet another environmental gateway to the development and globalisation of antimicrobial resistance. The Lancet Infection Diseases, 2016, Vol. 16 (7), Page: e127 – e133.

      Aquaculture uses hundreds of tonnes of antimicrobials annually to prevent and treat bacterial infection. The passage of these antimicrobials into the aquatic environment selects for resistant bacteria and resistance genes and stimulates bacterial mutation, recombination, and horizontal gene transfer. The potential bridging of aquatic and human pathogen resistomes leads to emergence of new antimicrobial-resistant bacteria and global dissemination of them and their antimicrobial resistance genes into animal and human populations. Efforts to prevent antimicrobial overuse in aquaculture must include education of all stakeholders about its detrimental effects on the health of fish, human beings, and the aquatic ecosystem (the notion of One Health), and encouragement of eco-friendly measures of disease prevention, including vaccines, probiotics, and bacteriophages. Adoption of these measures is a crucial supplement to efforts dealing with antimicrobial resistance by developing new therapeutic agents, if headway is to be made against the increasing problem of antimicrobial resistance in human and veterinary medicine.

003. Masato Akiba et al. Bacterial and Parasitic Disease Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, Ibaraki, Japan. Distribution and Relationships of Antimicrobial Resistance Determinants among Extended-Spectrum-Cephalosporin-Resistant or Carbapenem-Resistant Escherichia coli Isolates from Rivers and Sewage Treatment Plants in India. Antimicrobial Agents Chemotherapy, 2016, Vol. 60 (5), Page: 2972 - 2980.

      To determine the distribution and relationship of antimicrobial resistance determinants among extended-spectrum-cephalosporin (ESC)-resistant or carbapenem-resistant Escherichia coli isolates from the aquatic environment in India, water samples were collected from rivers or sewage treatment plants in five Indian states. A total of 446 E. coli isolates were randomly obtained. Resistance to ESC and/or carbapenem was observed in 169 (37.9%) E. coli isolates, which were further analyzed. These isolates showed resistance to numerous antimicrobials; more than half of the isolates exhibited resistance to eight or more antimicrobials. The bla_NDM-1 gene was detected in 14/21 carbapenem-resistant E. coli isolates:bla_NDM-1 in 2 isolates, bla_NDM-1 in 7 isolates, and bla_NDM-1 in 5 isolates. The bla_NDM-1-M gene was detected in 112 isolates (66.3%): bla_NDM-1-15 in 108 isolates and bla_NDM-1 in 4 isolates. We extracted 49 plasmids from selected isolates, and their whole-genome sequences were determined. Fifty resistance genes were detected, and 11 different combinations of replicon types were observed among the 49 plasmids. The network analysis results suggested that the plasmids sharing replicon types tended to form a community, which is based on the predicted gene similarity among the plasmids. Four communities each containing from 4 to 17 plasmids were observed. Three of the four communities contained plasmids detected in different Indian states, suggesting that the interstate dissemination of ancestor plasmids has already occurred. Comparison of the DNA sequences of theblaNDM-positive plasmids detected in this study with known sequences of related plasmids suggested that various mutation events facilitated the evolution of the plasmids and that plasmids with similar genetic backgrounds have widely disseminated in India.

003. Marc Lipsitch, George R. Siber. Center for Communicable Disease Dynamics, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA. How Can Vaccines Contribute to Solving the Antimicrobial Resistance Problem?. mBio, 2016, Vol.7 (3), Page: 1 – 8.

      There is a growing appreciation for the role of vaccines in confronting the problem of antimicrobial resistance (AMR). Vaccines can reduce the prevalence of resistance by reducing the need for antimicrobial use and can reduce its impact by reducing the total number of cases. By reducing the number of pathogens that may be responsible for a particular clinical syndrome, vaccines can permit the use of narrower-spectrum antibiotics for empirical therapy. These effects may be amplified by herd immunity, extending protection to unvaccinated persons in the population. Because much selection for resistance is due to selection on bystander members of the normal flora, vaccination can reduce pressure for resistance even in pathogens not included in the vaccine. Some vaccines have had disproportionate effects on drug-resistant lineages within the target species, a benefit that could be more deliberately exploited in vaccine design. We describe the effects of current vaccines in controlling AMR, survey some vaccines in development with the potential to do so further, and discuss strategies to amplify these benefits. We conclude with a discussion of research and policy priorities to more fully enlist vaccines in the battle against AMR.