28
Feb
Deadly Public Health Threat from Antifungal and Antibiotic Resistance Ignored by EPA
(Beyond Pesticides, February 28, 2022) When bacteria and fungi become resistant to pesticides, it is a signal that the toxic chemical approach to controlling pathogens does not work. But resistance also poses a direct threat to human health when the pesticide (or a related chemical) is used in human medicine.
The threat of resistance in bacterial human pathogens has long been widely recognized. Although research sponsored by the Environmental Protection Agency (EPA) recognizes the spread of resistance to antibiotics important in human medicine through horizontal gene transfer in the environment, EPA inaction both on antibiotic and antifungal resistance has become a growing crisis.
EPA does recognize the existence of resistance to fungicides. It uses codes produced by the Fungicide Resistance Action Committee in decisions regarding fungicide registration. Although EPA says resistance “may be considered in the risk-benefit decision-making process,” there is no evidence that the agency actually considers the failure of EPA-registered pesticides to control the target organisms in registering pesticides. That failure has a serious impact on human and environmental health as users of the chemical increase use and as medical uses of antibiotics and fungicides become ineffective.
The threat of resistance is evident with a number of fungicides, as well as bactericides and viricides. For example, Candida auris is an emerging fungal pathogen that threatens those with compromised or immature immune systems, such as infants, the elderly, people taking steroids for autoimmune disorders, diabetics, those undergoing chemotherapy, and even smokers. Nearly half of those who contract a C. auris infection die within 90 days. One of the factors making this fungus so deadly is that it has developed resistance to existing antifungal medicines, with 90% of infections resistant to one drug, and 30% to two or more. As is true for resistant bacteria, culprits in C. auris’s development of resistance include the use of antifungal medications in health care and reliance on fungicides in agriculture.
A recent study conducted by scientists at the University of Georgia finds fungicide use in agriculture is driving the spread of multi-fungicide resistant human pathogens. Of 700 Aspergillus fumigatus samples collected, nearly 20% (123) displayed some level of resistance to the commonly used azole fungicide tebuconazole. Twelve of the 123 were highly resistant at clinically relevant levels for human health care. No samples taken from organic sites contained resistant fungi.
Azole-resistant strains also displayed resistance to methyl benzimidazole carbamate (MBC) fungicides like carbendazim, and quinone outside inhibitors (Qol) like azoxystrobin.
A review of genome sequences shows that genetically those with broad resistance to azole fungicides show a close match between those discovered on farms and those found in human clinical settings. Of 25 pan-azole resistant samples analyzed, eight farm samples and 12 human clinical samples also display resistance to non-azole fungicides.
These results indicate a need for a shift toward eliminating reliance on toxic fungicides.
Unfortunately, regulators and politicians are neither heeding the science, nor listening to scientists. EPA’s recent response to the rise of drug-resistant Candida auris is a case in point. The agency failed to assess the efficacy of any pesticides that are not used for public health purposes; EPA only evaluated the efficacy of antimicrobial compounds whose use patterns classify them as human-health-related—thus ignoring the impact of other antimicrobial pesticides on resistance in human pathogens.
At the international level, a Freedom of Information Act request revealed officials at the U.S. Department of Agriculture working to downplay the role of synthetic fungicide use in chemical agriculture as a factor in the rise of drug-resistant fungal infections worldwide by denying the truth on the ground and attempting to halt protective actions, as EPA did with pentachlorophenol (recently cancelled with a 5-year phaseout after the manufacturer pulled out of the market). Prior research on resistance in agriculture has shown that the only true way to eliminate resistance is to stop using the material that was causing resistance to occur in the first place. Organic agriculture, with its strong restrictions on allowed synthetic materials, provides a path out of the industrialized chemical farming system that overtook agricultural production over the last century. Rising resistance, and the need to retain life-saving medications for protecting people’s health is another reason why investing in organic is the right choice for the future.
Letter to EPA:
When bacteria and fungi become resistant to pesticides, it signals that the toxic chemical approach to controlling pathogens does not work. But resistance also poses a direct threat to human health when the pesticide (or a related chemical) is used in human medicine. EPA must cancel all uses of a pesticide found to cause resistance.
The threat of resistance in bacterial human pathogens has long been widely recognized. Although research sponsored by the Environmental Protection Agency (EPA) shows the spread of resistance to antibiotics important in human medicine through horizontal gene transfer in the environment, EPA inaction both on antibiotic and antifungal resistance has become a growing crisis..
EPA recognizes the existence of resistance to fungicides by using codes produced by the Fungicide Resistance Action Committee in registration decisions. Although EPA says resistance “may be considered in the risk-benefit decision-making process,” there is no evidence that the agency actually considers the failure of EPA-registered pesticides to control the target organisms in registration—a failure that affects human and environmental health because those who depend on the pesticide use ever-higher amounts, as medical uses of antibiotics and fungicides become ineffective.
The resistance threat to human health is evident with a number of fungicides, bactericides, and viricides. For example, Candida auris is an emerging fungal pathogen that threatens those with compromised or immature immune systems, such as infants, the elderly, people taking steroids for autoimmune disorders, diabetics, those undergoing chemotherapy, and even smokers. Nearly half of those who contract a C. auris infection die within 90 days. One of the factors making this fungus so deadly is that it has developed resistance to existing antifungal medicines, with 90% of infections resistant to one drug, and 30% to two or more. Culprits in C. auris’s development of resistance include the use of antifungal medications in health care and reliance on fungicides in agriculture.
A recent study conducted by scientists at the University of Georgia finds fungicide use in agriculture is driving the spread of multi-fungicide resistant human pathogens. Of 700 Aspergillus fumigatus samples collected, nearly 20% (123) displayed some level of resistance to the commonly used azole fungicide tebuconazole. Twelve of the 123 were highly resistant at clinically relevant levels for human health care. No samples taken from organic sites contained resistant fungi.
Azole-resistant strains also display resistance to methyl benzimidazole carbamate fungicides like carbendazim, and quinone outside inhibitors like azoxystrobin. A review of genome sequences shows that genetically, those with broad resistance to azole fungicides show a close match between those discovered on farms and those found in human clinical settings.
These results indicate a need for a shift toward eliminating reliance on toxic fungicides.
EPA’s recent response to the rise of drug-resistant C. auris demonstrates EPA’s failure to use the science. The agency failed to assess the efficacy of pesticides not used for public health purposes, only evaluating the efficacy of antimicrobial compounds whose use patterns classify them as human-health-related—thus ignoring the impact of other antimicrobial pesticides on resistance in human pathogens.
Research shows that the only way to eliminate resistance is to stop using the material that was causing resistance to occur in the first place. Organic agriculture, with its strong restrictions on allowed synthetic materials, provides a path out of the industrialized chemical farming system that overtook agricultural production over the last century.
Rising resistance, and the need to retain life-saving medications for protecting people’s health require that EPA cancel all uses of a pesticide found to cause resistance.
Letter to U.S. Senators and Representative:
When bacteria and fungi become resistant to pesticides, it signals that the toxic chemical approach to controlling pathogens does not work. But resistance also poses a direct threat to human health when the pesticide (or a related chemical) is used in human medicine. EPA must cancel all uses of a pesticide found to cause resistance.
The threat of resistance in bacterial human pathogens has long been widely recognized. Although research sponsored by the Environmental Protection Agency (EPA) shows the spread of resistance to antibiotics important in human medicine through horizontal gene transfer in the environment, EPA inaction both on antibiotic and antifungal resistance has become a growing crisis..
EPA recognizes the existence of resistance to fungicides by using codes produced by the Fungicide Resistance Action Committee in registration decisions. Although EPA says resistance “may be considered in the risk-benefit decision-making process,” there is no evidence that the agency actually considers the failure of EPA-registered pesticides to control the target organisms in registration—a failure that affects human and environmental health because those who depend on the pesticide use ever-higher amounts, as medical uses of antibiotics and fungicides become ineffective.
The resistance threat to human health is evident with a number of fungicides, bactericides, and viricides. For example, Candida auris is an emerging fungal pathogen that threatens those with compromised or immature immune systems, such as infants, the elderly, people taking steroids for autoimmune disorders, diabetics, those undergoing chemotherapy, and even smokers. Nearly half of those who contract a C. auris infection die within 90 days. One of the factors making this fungus so deadly is that it has developed resistance to existing antifungal medicines, with 90% of infections resistant to one drug, and 30% to two or more. Culprits in C. auris’s development of resistance include the use of antifungal medications in health care and reliance on fungicides in agriculture.
A recent study conducted by scientists at the University of Georgia finds fungicide use in agriculture is driving the spread of multi-fungicide resistant human pathogens. Of 700 Aspergillus fumigatus samples collected, nearly 20% (123) displayed some level of resistance to the commonly used azole fungicide tebuconazole. Twelve of the 123 were highly resistant at clinically relevant levels for human health care. No samples taken from organic sites contained resistant fungi.
Azole-resistant strains also display resistance to methyl benzimidazole carbamate fungicides like carbendazim, and quinone outside inhibitors like azoxystrobin. A review of genome sequences shows that genetically, those with broad resistance to azole fungicides show a close match between those discovered on farms and those found in human clinical settings.
These results indicate a need for a shift toward eliminating reliance on toxic fungicides.
EPA’s recent response to the rise of drug-resistant C. auris demonstrates EPA’s failure to use the science. The agency failed to assess the efficacy of pesticides not used for public health purposes, only evaluating the efficacy of antimicrobial compounds whose use patterns classify them as human-health-related—thus ignoring the impact of other antimicrobial pesticides on resistance in human pathogens.
Research shows that the only way to eliminate resistance is to stop using the material that was causing resistance to occur in the first place. Organic agriculture, with its strong restrictions on allowed synthetic materials, provides a path out of the industrialized chemical farming system that overtook agricultural production over the last century.
Please ensure that in view of rising resistance, and the need to retain life-saving medications for protecting people’s health, that EPA cancels all uses of a pesticide found to cause resistance.
