Infectious diseases are a leading cause of death worldwide, and the diagnosis of bacterial infections remains a challenge in medicine. And given the increasing frequency of antibiotic resistance, it is more important than ever to ensure this is done. Now, the research published in ACS Central Science It has the potential to enable healthcare professionals to non-invasively diagnose bacterial infections using breath-based tests. Early experiments demonstrated the approach in animals suffering from pneumonia and infections of the bloodstream, muscles, and bones.
In designing this study, we were motivated by an evolving trend in clinical practice in which patients and healthcare professionals seek immediate answers to inform treatment decisions. When a patient presents to an emergency room or acute care clinic, we want to be able to diagnose an acute bacterial infection as efficiently as possible. ”
David Wilson, corresponding author of the study
Currently, doctors rely on blood tests, imaging tests, cultures, and molecular diagnostics to determine the cause of infections, but these tools are limited by being time-consuming, nonspecific, and expensive. The beginning to a potential solution could be the long-used breath test for Helicobacter pylori, a bacterium that causes common stomach infections. The original test works when you drink a liquid that contains traceable substances metabolized by H. pylori. The person then exhales into a device that measures labeled carbon dioxide in exhaled breath, indicating the presence of an infection. Inspired by this test, Wilson, Kiel Neumann, Marina López Álvarez and colleagues set out to expand the technology’s capabilities to detect a wider range of bacterial infections.
As prototypes, the researchers tested sugars and sugar alcohols tagged with carbon-13, a traceable form of carbon that bacteria metabolize but human cells largely ignore. In laboratory experiments, the researchers identified some of these compounds that bacteria convert to carbon-13-labeled carbon dioxide. They then analyzed the labeled gases using a simple technique called nondispersive infrared spectroscopy.
When mice suffering from infections such as pneumonia or bone, muscle, or blood infections were injected intravenously with these labeled compounds, the animals’ exhaled breath quickly showed elevated levels of labeled carbon dioxide. Although the breath testing protocol was not optimized in this study, the researchers said they typically saw an increase in the carbon-13 labeled breath signal in infected animals within the first 10 minutes of metabolite administration and breath sampling. In contrast, little or no carbon-13 was detected in the breath of healthy mice.
In one E. coli infection model, the amount of labeled carbon dioxide in exhaled breath decreased as bacterial levels decreased during antibiotic treatment, suggesting that the method could also be used to monitor the effectiveness of treatment.
The test could provide results faster than current methods because the breath testing device is portable and a breath signal appears within minutes of administering the traceable carbon-13. Additionally, the sugars and sugar alcohols used are considered safe for humans, and the researchers say this approach could eventually become a tool for diagnosing bacterial infections.
The authors acknowledge funding from the National Institutes of Health and the Cystic Fibrosis Foundation.
The authors have filed a U.S. patent related to this research.
sauce:
american chemical society
Reference magazines:
López Alvarez, M. Others. (2026) Detection of bacteria in mammalian hosts using a metabolically targeted (13C)CO2 breath test.ACS Central Science. DOI: 10.1021/accentsci.5c01995. https://pubs.acs.org/doi/10.1021/accentsci.5c01995
