An imaging agent allows scientists to better visualize Enterobacterales infections in patients, helping to address pathogens that can be life-threatening and frequently resist antibiotics.

The agent was safe in 26 patients and differentiated infections from either sterile inflammation or COVID-19-linked pneumonia. Enterobacterales is the largest group of disease-causing bacteria in humans and includes common pathogens such as Escherichia coli, Salmonella, and Klebsiella pneumoniae. These species have become increasingly resistant to common antibiotics, which has led the Centers for Disease Control to label some drug-resistant strains as urgent threats to human health.

However, scientists still lack tools that can rapidly and noninvasively detect Enterobacterales infections and determine where they are in the body, which is key for proper treatment and for research into new therapies. Building on previous work Alvaro Ordonez and colleagues tested an imaging agent they developed named 18F-FDS, which can detect Enterobacterales infections when combined with standard PET imaging. The agent safely and rapidly identified sites such as the lungs and liver that were infected by either drug-susceptible or drug-resistant Enterobacterales and could differentiate infections from inflammation or cancerous lesions.

The agent also revealed how 13 of the patients responded to antibiotics and helped identify patients who weren't responding to treatment. 18F-FDS also distinguished K. pneumoniae-caused pneumonia from pneumonitis caused by SARS-CoV-2, suggesting it could help clinicians pinpoint secondary bacterial infections. The researchers also developed a cartridge system that can rapidly synthesize 18F-FDS from a commercially available precursor, which they say is a major advantage of their system.