Researchers from Pasadena-based California Institute of Technology developed a new test that can pinpoint antibiotic-resistant bacteria within half an hour. The researchers published their findings in Science Translational Medicine.
The research team focused on urinary tract infections. The test involves collecting a sample of urine from a UTI patient. The sample is divided into two — one part is exposed to an antibiotic for 15 minutes, while the other part is not.
The bacteria in each sample are then broken open to release their cellular contents. The researchers run the contents through a process that combines a detection chemistry technique — called digital real-time loop-mediated isothermal amplification — and a device called a SlipChip. The process replicates specific DNA markers so they can be imaged and counted.
Typically, bacteria in antibiotic solutions will not be able replicate DNA as well as when they are not exposed to antibiotics. Thus, the test operates on the principle that if bacteria DNA replication is not hampered in an antibiotic environment, the bacteria are resistant to the antibiotic. The test will show similar numbers of DNA markers in both the treated and untreated solutions.
The researchers used the test on 54 samples of urine from UTI patients. The UTIs were caused by Escherichia coli. The test results had a 95 percent match with results obtained using the standard two-day test.