Heavy Metal Exposure Creates Antibiotic Resistant Bacteria

Heavy metals are known environmental contaminants that can be leached through a variety of human activities and interfere with access to safe drinking water and housing. Major news stories like those from Flint, MI, show us the prevalence of lead contaminated water within the United States and the disastrous health consequences that may result from long term exposure. Scientists have now discovered another major health consequence resulting from heavy metal contamination: an increase in antibiotic resistant bacteria.

Antibiotic resistant bacteria, otherwise known as “superbugs”, are specific strains of bacteria that do not respond to typical antibiotic treatment. Superbugs, like Methicillin-resistant Staphylococcus aureus (MRSA), were responsible for nearly 1.3 million deaths in 2019 and are a growing issue for medical and health scientists. Most superbugs developed through overuse of antibiotic medications, resulting in fast-breeding bacteria selecting for genetic traits that were immune to the antibiotic effects. Normally, heavy metals are toxic to bacteria species, but some have evolved to survive by ejecting metal ions, which also leads to the ejection of antibiotic drugs. Newly published research from the University of Wisconsin is now uncovering a trend between exposure to heavy metals and increased rates of antibiotic resistant bacteria within the human body.

Using samples from nearly 700 participants in the 2016 – 2017 Survey of the Health of Wisconsin, head researcher Shoshannah Eggers and her team found that elevated urine lead levels were predictive of higher antibiotic resistant bacteria counts, after accounting for additional resistance factors. Researchers also found that lead levels as well as levels of antibiotic resistant bacteria were higher in both urban residents and minority populations, with nonwhite urban residents being 76% more likely to test positive for the presence of a superbug than white urban residents.

The pathways and mechanisms that lead to antibiotic resistance are still under investigation, but the epidemiologic links have sparked concern for both public health officials and environmental justice advocates. Minimizing exposure to lead and other heavy metals is not only important in the fight against chronic health effects, but will also slow the development of antibiotic resistant bacteria species.

Shoshannah Eggers is a postdoctoral fellow in the Department of Environmental Medicine and Public Health at the Icahn School of Medicine at Mount Sinai. She completed her PhD in Population Health Science with a concentration in Epidemiology at the University of Wisconsin School of Medicine and Public Health. Her research focuses on environmental epidemiology and impacts to the humane microbiome.

Managing Correspondent: Samantha Tracy
Press Article: “Living with Lead Creates Antibiotic-Resistant ‘Superbugs’”
Journal Article: “Urinary lead level and colonization by antibiotic resistant bacteria: Evidence from a population-based study”
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