Bowling Green Study Uncovers Hidden Danger in Used Needles—and a Potential New Ally

The opioid crisis has claimed more than 100,000 American lives annually since 2021, but the toll extends beyond overdose deaths. A research team at Bowling Green State University has uncovered a hidden danger lurking in the equipment used by people who inject drugs—and simultaneously identified a potential natural ally that could open new pathways for treating drug-resistant infections.

Through a partnership with the Toledo Lucas County Health Department, biological sciences professor Hans Wildschutte, Ph.D., and his team analyzed used hypodermic needles collected from Northwest Ohio Safe Services, the county's needle exchange program. The researchers sought to understand what substances were actually present in the needles and whether any non-viral pathogens could be detected. What they found exceeded their expectations in both alarm and promise.

An Unexpected Fungal Threat

The average needle contained eight different chemical compounds, but one finding stood out: 86% of tested needles contained xylazine, the powerful veterinary tranquilizer increasingly mixed with fentanyl in the illicit drug supply. This prevalence far exceeds previous estimates and underscores how thoroughly xylazine has permeated street drugs.

More surprising, however, was the discovery of Candida—a fungal pathogen capable of causing life-threatening bloodstream infections. "We thought there was just going to be bacteria in there, so when there was Candida, for me, that was a big surprise," Wildschutte said.

Candida infections, while often associated with relatively benign conditions like thrush or urinary tract infections, become deadly when they enter the bloodstream. For people who inject drugs, this represents a realistic and underappreciated risk. The emergence of multidrug-resistant fungal strains like Candida auris—already detected in hospitals across 27 states—makes the threat particularly concerning.

"We see Candida is already in a lot of hospitals in quite a few states, which is a big concern because we don't have as many antifungal treatments, especially when compared to antibiotics," explained Nara Souza, a doctoral student from Brazil who collaborated on the project. "The antifungal medications can have more side effects and can even be toxic to humans, which can limit treatment options."

A Soil Bacterium Steps In

Amid these concerning findings, the BGSU team identified what could become a valuable therapeutic tool. Certain strains of Pseudomonas, a soil-dwelling bacterium, demonstrated the ability to kill Candida in laboratory tests. This discovery could lead to novel treatments for fungal infections at a time when existing antifungal medications face growing resistance.

The research, published in the peer-reviewed journal PLOS One, represents an early but promising step toward addressing a global health challenge. Approximately two million people worldwide die from fungal infections annually, and that number continues to rise as drug resistance spreads.

Biological sciences graduate student Michael Fyfe, who gained his first research experience as a BGSU undergraduate before continuing in Wildschutte's lab, noted that the team was able to manipulate Pseudomonas to enhance its antifungal properties. "We did see some novel interactions that could lead us to some exciting places if we explore this further," Fyfe said. "There were times that we were able to, in essence, edit the genome to produce more of the antifungal compound."

Implications for Harm Reduction

The findings carry significant implications for harm reduction strategies. Needle exchange programs like Northwest Ohio Safe Services were established primarily to reduce transmission of bloodborne viruses such as HIV and hepatitis C. While these programs have proven effective at that mission, the BGSU research suggests they may also be preventing a parallel epidemic of fungal infections that has received far less attention.

"Every time we do these tests, it's really remarkable that these bacterial strains are able to kill not only these dangerous fungi, but even some multi-drug-resistant pathogens," Wildschutte said.

The research highlights the complex ecosystem of risks facing people who inject drugs. Beyond the immediate threat of overdose from potent synthetic opioids, users confront exposure to xylazine—which causes severe skin wounds and complicates overdose reversal—and now, potentially deadly fungal pathogens. Each of these dangers compounds the others, creating a public health challenge that extends far beyond the single metric of overdose mortality.

From Local Data to Global Solutions

While the study focused on northwestern Ohio, its implications reach worldwide. The intersection of intravenous drug use and infectious disease represents a growing concern as synthetic opioids continue to dominate illicit markets globally. The discovery of Pseudomonas's antifungal properties offers a potential avenue for developing new treatments that could benefit populations well beyond those who use drugs.

The research also demonstrates the value of academic-public health partnerships. By combining the resources of a university laboratory with the practical access provided by a county health department's harm reduction program, the team was able to gather data that would be difficult to obtain through either approach alone.

For Wildschutte and his colleagues, the work represents both scientific achievement and public health contribution. As fungal infections claim increasing numbers of lives worldwide—particularly among immunocompromised populations and those with limited access to healthcare—the identification of new therapeutic candidates becomes ever more urgent.

The BGSU study suggests that solutions to complex health crises may emerge from unexpected places: in this case, from the soil beneath our feet and the syringes collected through programs designed to serve marginalized communities. Whether Pseudomonas will ultimately yield clinically viable treatments remains to be seen through further research, but the discovery itself illustrates how addressing the opioid crisis requires attention to its many dimensions—some visible, others hidden until researchers know where to look.