Biological sciences: Live imaging of bacterial infection

Fluorescently labelled vancomycin - an antibiotic used to treat bacterial infections - can be used to detect bacterial infection in animals and biomaterial-associated infections in human cadavers. The work, published this week in Nature Communications, represents a sensitive, specific, and non-invasive method for detecting bacterial infections that may be caused by biomaterials in the form of implants.

Marleen van Oosten, Gooitzen van Dam, Jan Maarten van Dijl and colleagues injected a single dose of the fluorescently labelled vancomycin to mice infected with Staphylococcus aureus. This dose was several times lower than the dose used in humans to elicit a therapeutic response. The following day they could pinpoint the sites of bacterial infection in these animals using a non-invasive real-time optical imaging. They also tested the probe in a human cadaver that received infected implants post mortem. They found that a single application of fluorescent antibiotic was sufficient to detect bacteria located on superficially implanted medical devices. The authors report that the technique also allows for the distinction between inflammation caused by bacterial infections and non-bacterial inflammation.

This is of potential importance as biomaterial-associated infections constitute an important clinical burden, and so far there are no sensitive, specific, and non-invasive methods for detecting these infections in patients.