Researchers at the Technion-Israel Institute of Technology have found a way to treat patients with urgent bacterial infections days earlier than is currently possible, a discovery which could save many lives.
The researchers have developed a diagnostic device that rapidly analyzes bacteria from patients with infections and identifies which antibiotics the bacteria are resistant to, allowing doctors to quickly prescribe the most effective antibiotic for the infection.
Quick treatment is vital for patients’ lives. According to established estimates, for every hour that effective antibiotic treatment is delayed, survival rates drop by around 7.6% for patients with septic shock (a condition where an infection causes organs to malfunction, often resulting in death).
The device developed by the Technion researchers, called the SNDA-AST, is a chip with hundreds of minuscule wells inside it, each containing a few bacteria and a specific antibiotic. Using a fluorescent marker, image processing tools, and statistical analysis of the colors obtained, the researchers are able to determine the response of the bacteria to each type of antibiotic. In the study conducted, 12 bacteria-antibiotic combinations were tested using the device, and the scientists obtained data on bacterial resistance rapidly and accurately.
The Threat of Bacterial Resistance
Antibiotics are one of the most effective ways to treat bacterial infections.
Bacterial infections occur when harmful bacteria multiply within the body. Normally, our immune systems are able to fight off the bacteria; sometimes, however, our body is unable to cope. Antibiotics help our immune systems by either stopping the harmful bacteria cells from reproducing, or simply killing the cells.
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Since the first antibiotic, penicillin, was discovered in 1928, antibiotics have been widely used to treat bacterial infections. However, widespread prescription has led to many strains of bacteria becoming resistant to the antibiotics – a phenomenon known as antimicrobial resistance (AMR). There is increasing concern about the harm caused by AMR: In 2014, AMR claimed the lives of more than 700,000 people worldwide, in addition to a cumulative expenditure of $35 billion a year in the US alone.
Because of the urgency of treating threatening infections, doctors often prescribe antibiotics that target a broad range of bacteria in large doses. This, however, makes it more likely that the bacteria will develop resistance, and also affects the population of “good bacteria” that protects the human body (known as microbiota).
By identifying whether bacteria are resistant to specific antibiotics, and the extent of this resistance, the system developed at Technion enables healthcare teams to choose the most effective antibiotic a day or two earlier than with traditional methods.
According to Avesar, “Every day, tens to hundreds of tests are carried out at every hospital in Israel to map the resistance levels of infectious bacteria from samples taken from patients. The problem is that this is a very long test, since it is based on sending the sample to the lab, growing a bacterial culture in a petri dish, and analyzing the culture. This process requires relatively large sampling and usually takes a few days, in part because the workday at labs is limited to around eight hours. Our method, on the other hand, provides accurate results in a short time based on a much smaller sample. It is obvious that a faster response allows us to start treatment earlier and improve the speed of recovery.”
The benefits of the device are significant. According to Jonathan Avesar, a doctoral student and member of the research team, “The use of the technology that we developed reduces the size of the required sample by several orders of magnitude, reduces the scanning time by around 50%, and significantly reduces the lab space required for testing and reduces the cost per test.”
The study was led by Prof. Shulamit Levenberg, Dean of the Technion Faculty of Biomedical Engineering, and was carried out by three researchers in her lab: doctoral student Jonathan Avesar, postdoctoral student Dekel Rosenfeld, and doctoral student Tom Ben-Arye. The study was carried out in cooperation with Assistant Professor Moran Bercovici of the Technion Faculty of Mechanical Engineering and doctoral student Marianna Truman-Rosentsvit, in cooperation with Dr. Yuval Geffen, head of the Microbiology Laboratory at Ramban Health Care Campus. It was funded by a KAMIN grant from the Innovation Authority and the Israeli Centers of Research Excellence (I-CORE). The findings were published in June 2017, in the Proceedings of the national Academy of Sciences (PNAS).