Researchers from Germany, the United States and Puerto Rico have developed a portable diagnostic kit that’s capable of detecting multidrug resistant pathogens in a timely manner. The hope is this device may reduce unnecessary use of broad spectrum antibiotics in developing countries where diagnostic resources are in limited supply.
Research on the technology was published in Applied and Environmental Microbiology.
“Antibiotic resistance is a serious threat to human health and a significant challenge for modern medicine,” the researchers emphasized in the article. Worldwide, about 4.6 million people die from microbial infections each year, with many of those deaths taking place in developing countries. In the United States, it’s estimated that methicillin-resistant Staphylococcus aureus (MRSA) causes more than 11,000 deaths annually.
One particular cluster of bacteria known as the “ESKAPE” panel: Enterococcus faecium, S. aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp pose a specific threat to public health due to their known resistance to a number of clinical antibiotics.
Overuse of broad spectrum antibiotics is a specific problem in isolated areas with few diagnostic facilities. Without an effective, timely method for identifying deadly bacteria, clinicians often resort to these antibiotics to treat patients, which increases the risk of antibiotic resistance, said the study’s lead author Lars D. Renner, PhD, group leader at the Leibniz Institute of Polymer Research, and the Max Bergmann Center of Biomaterials, Dresden, Germany, in a statement.
“Proper drug use is necessary to mitigate the growing emergence of antibiotic resistance,” the researchers stressed in their article. The portable and inexpensive assay they developed rapidly identifies ESKAPE bacteria using a bacteria detection or B-chip. The chip is a “de-gas driven microfluidic cartridge that performs dozens of multiplexed [recombinase polymerase amplification] RPA assays to detect ESKAPE bacterial pathogens from a small sample volume,” they explained.
Each of the device’s 16 microchambers contains a genetic sequence for a specific pathogen. A chamber will “light up” in the event a patient’s sample matches up with one of these genetic sequences. An app then identifies what specific pathogen(s) are in the sample. According to the researchers, the device needs just 10 DNA sequences from the patient sample to identify a pathogen.
In their results, the researchers said they were able to identify five of the ESKAPE strains using the portable device. “[It] has detection limits that are generally comparable to more expensive, large-scale laboratory equipment used for the detection of bacterial pathogens,” they observed in the article. While they were able to create unique probe and primer sets to detect E. faecium, S. aureus, K. pneumoniae, A. baumannii, and P. aeruginosa, they were not able to do so for Enterobacter.
The assays were unable to distinguish between live and dead bacteria—a factor that could produce false positive test results. “One way to transcend this limitation is to shift to detecting [messenger] mRNA (rather than DNA) by taking advantage of its more rapid rate of degradation once released from cells into the environment,” the researchers suggested.
The hope is this technology “may enable future diagnoses of bacteria to guide the development of effective chemotherapies, and may have a role in areas beyond health where rapid detection is valuable, including in industrial processing and manufacturing, food security, agriculture, and water quality testing,” they said.