Environment Research

February 17, 2016 – New research has shown that tackling antibiotic resistance on only one front is a waste of time because resistant genes are freely crossing environmental.

Analysis of historic soil archives dating back to 1923 has revealed a clear parallel between the appearance of antibiotic resistance in medicine and similar antibiotic resistant genes detected over time in agricultural soils treated with animal manure.

Collected in Denmark – where antibiotics were banned in agriculture from the 1990s for non-therapeutic use – the soil archives provide an 'antibiotic resistance timeline' that reflects resistant genes found in the environment and the evolution of the same types of antibiotic resistance in medicine.

Led by Newcastle University, UK, the study also showed that the repeated use of animal manure and antibiotic substitutes can increase the capacity of soil bacteria to mobilize, or ready themselves, and acquire resistance genes to new antibiotics.

Publishing their findings in the academic journal Scientific Reports, the study's authors say the data highlights the importance of reducing antibiotic use across all sectors if we are to reduce global antibiotic resistance.

"The observed bridge between clinical and agricultural antibiotic resistance means we are not going to solve the resistance problem just by reducing the number of antibiotics we prescribe in our GP clinics,” said lead author David Graham, professor of ecosystems engineering at Newcastle University.

"To reduce the global rise in resistance, we need to reduce use and improve antibiotic stewardship across all sectors. If this is not done, antibiotic resistance from imprudent sectors will cross-contaminate the whole system and we will quickly find ourselves in a situation where our antibiotics are no longer effective."

Antibiotics have been used in medicine since the 1930s, saving millions of lives. Two decades later, they were introduced into agricultural practices and Denmark was among the leaders in employing antibiotics to increase agricultural productivity and animal production.

However, a growing awareness of the antibiotic resistance crisis and continued debate over who and which activities are most responsible led to the EU calling for the use of antibiotics in non-therapeutic settings to be phased out and Denmark led the way.

The Askov Long-Term Experiment station in Denmark was originally set up in 1894 to study the role of animal manure versus inorganic fertilizers on soil fertility.

Analyzing the samples, the team – involving experts from Newcastle University, the University of Strathclyde and Aarhus University – were able to measure the relative abundance of specific β-lactam antibiotic resistant genes, which can confer resistance to a class of antibiotics that are of considerable medical importance.

Prior to 1960, the team found low levels of the genes in both the manured soil and that treated with inorganic fertilizer. However, by the mid 1970s, levels of selected β-lactam genes started to increase in the manured soils, with levels peaking in the mid 1980's. No increase or change was detected in the soil treated with inorganic fertilizer.

"We chose these resistant genes because their appearance and rapid increase in hospitals from 1963 to 1989 is well-documented," explains Professor Graham.

"By comparing the two timelines, we saw the appearance of each specific gene in the soil samples was consistent with the evolution of similar types of resistance in medicine. So the question now is not which came first, clinical or environmental resistance, but what do we do about it?"

Following the ban on non-therapeutic antibiotic use in Danish agriculture, farmers substituted metals for antibiotics, such as copper, and levels of the key β-lactam genes in the manured soils declined rapidly, reaching pre-industrialization levels by 2010.

However, at the same time the team measured a 10-fold rise in Class 1 Integrons. These are gene carrier and exchange molecules – transporters that allow bacteria to readily share genes, including resistance genes.

These findings suggest the application of manure and antibiotic substitutes, such as copper, may be 'priming' the soils, readying them for increased resistance transmission in the future.

"Once antibiotics were banned, operators substituted them with copper which has natural antibiotic properties," explains Professor Graham.

"More research is needed but our findings suggest that by substituting antibiotics for metals such as copper we may have increased the potential for resistance transmission.

"Unless we reduce use and improve stewardship across all sectors – environmental, clinical and agricultural – we don't stand a chance of reducing antibiotic resistance in the future."

Published in Environment

May 17, 2013. The Honourable Gary Goodyear, Minister of State (Science and Technology), has announced that seven innovative environmental projects will benefit from more than $32 million in research funding over five years, via the new Climate Change and Atmospheric Research (CCAR) initiative. The funding will support teams composed of university researchers, scientists and partner organizations who will work together to advance the understanding of risks related to climate change.

"Our government is supporting research related to climate change through the creation of the Climate Change and Atmospheric Research initiative," says Goodyear. "We are confident that the knowledge generated through these projects will help improve the quality of life of all Canadians."

Established in 2011, CCAR is administered by the Natural Sciences and Engineering Research Council of Canada (NSERC) and supports climate change and atmospheric research at Canadian post-secondary institutions. Research projects funded through CCAR involve interpreting earth system processes, advancing weather, climate and environmental prediction and understanding recent changes in the Arctic and cold region environments.

"Strong environmental leadership includes strategic investments in science and research," adds the Honourable Peter Kent, Minister of the Environment. "Canadians will benefit in many ways from the project grants announced today. Our understanding of climate science and atmospheric processes in the North will be strengthened through increased collaboration between university and government scientists."

"The knowledge and expertise being brought together as part of these innovative research networks give Canada an advantage in understanding and predicting climate," said Isabelle Blain, Vice-President of Research Grants and Scholarships at NSERC. "The insights provided by these diverse and talented teams will showcase Canada's world-class research capacity in key areas of climate and atmospheric research and innovation."

The seven teams receiving grants of up to $5 million over a maximum of five years through the CCAR initiative are:

  • Network on Climate and Aerosols (NETCARE): Addressing Key Uncertainties in Remote Canadian Environments
  • Research related to the Polar Environment Atmospheric Research Laboratory (PEARL): Probing the Atmosphere of the High Arctic
  • Canadian Arctic GEOTRACES Program: Biogeochemical and Tracer Study of a Rapidly Changing Arctic Ocean
  • Canadian Sea Ice and Snow Evolution (CanSISE) Network Ventilation, Interactions and Transports Across the Labrador Sea (VITALS) Canadian Network for Regional Climate and Weather Processes; and
  • Changing Cold Regions Network (CCRN).

Since 2006, the Harper Government has provided more than $9 billion in new funding for initiatives to support science, technology and the growth of innovative firms. Economic Action Plan 2013 builds on this strong foundation, helping to position Canada for sustainable, long-term economic prosperity and provide a higher quality of life for Canadians.

NSERC is a federal agency that helps make Canada a country of discoverers and innovators for all Canadians. The agency supports almost 30,000 post-secondary researchers and post-doctoral fellows in their advanced studies. NSERC promotes discovery by funding approximately 12,000 professors every year and fosters innovation by encouraging over 2,400 Canadian companies to participate and invest in post-secondary research projects.

For more information on the CCAR initiative and to learn more about each project, please visit NSERC's website (www.nserc-crsng.gc.ca).

Published in Environment

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