Johns Hopkins scientists develop real-time diagnostic system for drug-resistant bacteria

Amid the rise of antibiotic-resistant superbugs in hospital systems and facilities, scientists at Johns Hopkins are developing a real-time tracking system that could quickly diagnose and monitor antibiotic-resistant bacterial infections.

Researchers combined a PET scanner with a new chemical tracing tool that can rapidly identify specific types of drug-resistant bacteria and provide feedback on how the bacteria respond to antibiotics, targeting diseases such as fatal pneumonias or bloodstream infections acquired in and out of the hospital. Although Johns Hopkins researchers conducted the research in mice, the results could easily be applied to humans because the system uses readily available imaging devices to detect bacterial infections, scientists said in a statement.

The researchers published their findings in the Oct. 22 issue of Science Translational Medicine.

"Our approach could quickly and reliably detect infections caused by certain Gram-negative organisms and could speed up diagnosis and treatment by eliminating days-long waits for lab test results," Dr. Edward Weinstein, a study co-author and infectious disease specialist at Johns Hopkins University School of Medicine, said in a statement. "Perhaps more importantly, the technique can give us critical insights into the basic mechanisms of disease and can help us evaluate the effect of drug therapy quickly."

Unlike other diagnostic imaging tools for infectious disease, the researchers' model uses sorbitol, an ingredient commonly found in sugar-free foods, to pinpoint bacteria and other harmful organisms. Scientists injected mice with clusters of Gram-negative bacterium Escherichia coli and harmless dead bacteria and then targeted the injections with a radio-labeled sorbitol tracer. Both injections caused inflammation, but only the cluster of live E. coli attracted the radio tracer and lit up the screen. The tool could also distinguish between inflammation caused by cancer from that caused by infection.

In the future, the new imaging system could reduce the use of broad-spectrum antibiotics to treat patients as well as track how bacteria respond to drugs over time, providing more effective treatment methods, the scientists said in a statement.

Meanwhile, diagnostics companies are hard at work developing molecular tests for drug-resistant bacteria and infections. In June, molecular diagnostics company Cepheid ($CPHD) said it would partner with pharma giants AstraZeneca ($AZN), GlaxoSmithKline ($GSK) and Cubist Pharmaceuticals ($CBST) to develop a rapid diagnostic test for multidrug-resistant pathogens. Silicon Valley startup InSilixa recently roped in $13 million to develop its innovative molecular diagnostic for drug-resistant bacteria. The Sunnyvale, CA-based company's system uses semiconductor-based technology to scan and verify the presence of genetic mutations that lead to antibiotic resistance.

- read the statement from Johns Hopkins Medical
- here's the Science Translational Medicine abstract