Overused fungicides give rise to deadly, resistant fungus threatening humans and crops

(NaturalNews) Nature always finds a way. Despite the advanced technology that humans possess, nature always seems to be one step ahead. This is particularly true for drug-resistant fungi, a phenomenon threatening enough to demand further research.

Four years ago, Dutch researchers were the first to link the agricultural use of fungicides to resistant fungi, particularly Aspergillus fumigatus, a common fungus that's seemingly developed a resistance to Western medicine.

Publishing in the December 2009 issue of The Lancet Infectious Diseases, scientists suggested that the massive use of fungicides on European orchards, vineyards and grain fields contributed to the resistance against drugs used to treat people with a life-threatening infection of A. fumigatus.

A. fumigatus typically affects those with weakened immune systems, causing wheezing in asthmatics and deadly lung infections. The fungus is commonly found in nature feeding on dead and decaying organic matter. It reproduces by spreading spores through the air, which are sometimes inhaled by humans.

More than 3 million people each year suffer from serious A. fumigatus infections, and the number of cases resistant to antifungal drugs is increasing, with no new antifungal medications currently being developed.

First researchers to link resistant fungi to agricultural fungicides were accused of scaring the public

Critics gawked at the Dutch team's research, accusing the study's authors of "crying wolf" and "publicity seeking" by scaring the public "in the way horror films do."

However, four years later, experts in Europe, Canada, China and India came to similar conclusions about drug-resistant fungi being linked to the agricultural use of fungicides.

The emerging fungi are resistant not only to agricultural fungicides but closely related medicines as well.

Biologist Jianping Xu published a study in June which found that nearly 30 percent of more than 300 types of yeast samples taken from the mouths of hospital patients in China were resistant, according to Canada.com.

Xu, who specializes in fungi genetics, said the findings came as a surprise, considering that none of the patients were on triazole medications, which can lead to the emergence of drug-resistant organisms.

The use of triazole fungicides increased almost 50 percent in China from 2000 to 2011, leading Xu to suggest that the patients picked up the resistant yeast from the environment before getting to the hospital.

Resistant strains of A. fumigatus were found in tea gardens, rice paddies and flowerpots in a hospital garden, according to Xu's research team.

"The type of resistance seen in the fungi is consistent with agricultural fungicides in the environment causing 'cross resistance to medical triazoles,'" reported the team in the journal PLOS ONE, as explained by Canada.com.

This fall, Xu says his group at McMaster University in Hamilton, Ont., hopes to test fungi circulating in the southern Ontario farm belt where corn and canola are commonly sprayed with triazoles. Triazole-based drugs are the first line of defense againstAspergillus fumigatus.

Research linking agricultural fungicides to resistant fungi goes global

The results of a three-year study convinced researchers in the United Kingdom to make the link between drug resistance in Aspergillus and fungicides used on crops, according to a press release by the University of Manchester.

Researchers from Radboud University Medical Centre and the University of Manchester compared resistant profiles in 230 fungal samples, collected from rural areas in West Yorkshire that were treated with fungicides, to 290 air and soil samples from inner-city sites across Greater Manchester.

Nearly 2 percent of resistance was detected in the rural samples taken from the West Yorkshire region, but none of the inner-city area samples showed resistance, implicating fungicides as the cause.

According to Science Daily, Guus van Muijlwijk of the Department of Medical Microbiology at Radboud University believes that the "merging antifungal resistance in human pathogenic fungi is causing a huge threat to patients, especially to those with [weakened] immune systems, and this study emphasises that there may be even a greater problem in treating such diseases."

Additional sources:

http://www.canada.com

http://www.plosone.org

http://www.sciencedaily.com

http://www.vwa.nl [PDF]

http://www.manchester.ac.uk

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