New, faster sepsis test could save lives, scientists say

Scientists have developed a new test that can diagnose deadly bacterial infections and identify the most appropriate antibiotic to treat them more than two days earlier than conventional approaches can.

Reducing turnaround times from infection to treatment could save patients from dying of sepsis, a serious condition in which the body overreacts to an infection, triggering tissue damage and organ failure. Once sepsis sets in, it can kill a patient within 12 hours. The goal of the new test is to identify the bacterial target quickly so the infection can be snuffed out before it advances to sepsis.

The test could also help curb the overuse of broad-spectrum antibiotics, meaning drugs that kill a wide range of bacteria. Broad-spectrum antibiotics can be useful when the exact culprit behind an infection is unknown. But the drugs can also fuel antibiotic resistance, pressuring microbes to evolve so they can survive the treatment.

The new test could help doctors pick the right "narrow-spectrum" drug faster, thereby reducing doctors' reliance on broad-spectrum solutions, according to the researchers who developed it. They described their findings in a paper published Wednesday (July 24) in the journal Nature.

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Normally, if a doctor suspects that a hospitalized patient has a bacterial infection, they will start the patient on broad-spectrum antibiotics before sending a sample of their bodily fluids for antimicrobial susceptibility testing (AST). This sample is taken from the site of the infection; for instance, urine would be used for a suspected urinary tract infection and blood for a suspected bloodstream infection.

This sample is then cultured in a lab, meaning it's stored such that the microbes within it can grow and multiply to the point that they can be detected by a test. Then, after a culprit bacterial species is identified, scientists test a range of antibiotics at different concentrations to determine which formula works best. At that point, the patient would be switched to a more-targeted treatment.