Fungicides for crops: worrying link to fungal drug resistance warn scientists

New research by British and Dutch scientists has found that Aspergillus – a common fungus that attacks the lungs and is found in soil and other organic matter – has become resistant to life - saving drugs in parts of rural Yorkshire.

 

It’s the first time a link has been made in the UK between drug resistance in Aspergillus and fungicide used on crops. Experts warn their findings, now published, are significant and raise serious implications for transplant patients, those with leukaemia and people who suffer from severe asthma.

 

In the three-year study, researchers from The University of Manchester and Radboud University, in the Netherlands, compared resistance profiles in 230 fungal samples, collected from rural areas in West Yorkshire which were treated with fungicides, to 290 air and soil samples from inner city sites across Greater Manchester. 

 

They found no resistance from the sites in Greater Manchester compared to 1.7% resistance detected in West Yorkshire, implicating fungicide use in agriculture.

 

Dr Michael Bromley, Lecturer at The University of Manchester and study leader commented: “Given the frequent finding of resistance across northern Europe, it is not a surprise to see resistance in the UK. However, the clear association with triazole fungicide usage is very worrisome, as some unlucky people at risk will breathe in untreatable Aspergillus, with potentially dire consequences.”

 

Diseases caused by Aspergillus affect millions of people worldwide, causing high morbidity and mortality. The only oral antifungal agents (triazoles) for human use are similar in structure to certain fungicides. The use of certain compounds in agriculture, notably difenoconazole, propiconazole, epoxiconazole, bromuconazole and tebuconazol are particularly likely to lead to resistance, yet are freely used in agriculture. There is a very limited range of antifungal compounds to treat fungal diseases, and some fungi are multi-resistant.

 

The emerging antifungal resistance in human pathogenic fungi is causing a huge threat to patients, especially to those with weaken immune systems and this study emphasises that there may be even a greater problem in treating such diseases. Previously such resistance has been observed in a few other countries (Netherlands, Denmark, Belgium, Germany, France, India, China, Iran, Tanzania and a few others) raising great concerns among clinicians. No new classes of antifungal agent are currently in clinical development. 

 

These findings come as the Government has announced of a review of the economics of antimicrobial research. However, experts believe current practice across both health and veterinary services is failing to prevent the inappropriate prescription of antibiotics. The Science and Technology Committee has warned that the Government needs to set clear responsibilities at all levels of the NHS and veterinary medicine to achieve better stewardship of the antimicrobial drugs vital in modern medicine.

 

*  The findings are published by the International Society for Chemotherapy of Infection and Cancer  as Bromley MJ, et al. Occurrence of azole-resistant species of Aspergillus in the UK environment in the Journal of Global Antimicrobial Resistance (2014).

 

Scientists on the research team included Dr Michael J. Bromley, Guss van Muijlwijk, Dr Marcin G. Fraczek, Dr Geoff Robson, Prof Paul E. Verweij, Prof David W. Denning and Dr Paul Bowyer. Guus is a now a final year medical student at Radboud University, and he contributed to the research during an exchange visit in Manchester.

 

The University of Manchester 

 

The University of Manchester, a member of the prestigious Russell Group of British universities, is the largest and most popular university in the UK. It has 20 academic schools and hundreds of specialist research groups undertaking pioneering multi-disciplinary teaching and research of worldwide significance. According to the results of the 2008 Research Assessment Exercise, The University of Manchester is one of the country’s major research institutions, rated third in the UK in terms of ‘research power’, and has had no fewer than 25 Nobel laureates either work or study there. The University had an annual income of £807 million in 2011/12.

 

The National Aspergillosis Centre (www.nationalaspergillosiscentre.org.uk) is the UK’s referral clinic for patients with chronic pulmonary aspergillosis and related conditions. It was established five years ago and is housed at the University Hospital of South Manchester and funded through the National Health Service Specialised Services. The Aspergillus Website (www.aspergillus.org.uk) was set up in 1998 by the Fungal Infection Trust. It is the most comprehensive source of information about Aspergillus and the diseases it causes available on the Internet. An estimated 75,000 distinct IP addresses log on monthly and over 200,000 other websites link to the Aspergillus Website. Well over 70% of users in any month are new visitors from over 125 countries. Over 1,000 patients are currently registered with the support discussion group on Yahoo! with another 150 on Facebook with 280 LinkedIn members (Aspergillus and Aspergillosis Group).