Novel holographic microscopy technique rapidly identifies bacteria
A new microscopy technique that creates holographic images from bacteria may be more efficient than culturing and other traditional methods for identifying bacteria, according to research published in Optics Express.
“Rapid and accurate identification of bacterial species is crucial for diagnosing infectious diseases or screening for poisoning sources in food,” YongKeun Park, PhD, of the Korea Advanced Institute of Science and Technology, Daejeon, South Korea, and colleagues wrote. “Bacterial infection causes a number of severe diseases and syndromes that all require immediate and appropriate treatment based on the detection and identification of the bacterial species.”
The novel method for identifying bacteria involves shooting laser light onto individual bacteria under a microscope to create holographic images. Bacteria is then classified using a mathematical function called a Fourier Transform and specially designed sorting software, which is similar to what computers use for facial recognition, according to a press release.
“Employing laser holographic techniques, we achieved rapid and label-free identification of bacterial species at the single bacterium level with a single-shot measurement,” Park said in the release. “This means the present method can be utilized as a prescreening test for point-of-care bacterial diagnosis for various applications including medicine and food hygiene.”
Blood culturing and real-time quantitative PCR (qPCR) typing are effective at identifying bacteria but they can take up to days and be cost-prohibitive, according to the investigators. The method introduced by Park and colleagues can identify individual bacteria more efficiently and with accuracy greater than 94%, they wrote.
“We have also developed a compact portable device, [the] so-called quantitative phase imaging unit, to convert a simple existing microscope to a holographic one ... which can then be used to identify bacteria species for rural areas and developing countries,” Park said. “Our team has plans to go to Tanzania next month for a field test.” – by David Jwanier
Disclosure: Jo acknowledges support from KAIST Presidential Fellowship and SPIE Optics & Photonics Education Scholarship.