Developers assess many considerations when making the determination of the size of a multiplex panel: comprehensiveness versus actionability, efficiency versus sensitivity. While targeted, moderately sized solutions are likely ideal for most common conditions, researchers at Lawrence Livermore National Laboratory (California) are developing a super assay for global disease surveillance and for instances when there is not a suspected pathogen. The Lawrence Livermore Microbial Detection Array (LLMDA) is capable of detecting virtually any microbe that has been sequenced, with results in 24 hours. The researchers see configuration of the assay as possible for a wide range of clinical applications. It has demonstrated success, for instance, in detecting bacterial pathogens in the wounds of U.S. soldiers. The LLMDA was able to detect at least one bacterial pathogen in roughly one-third of wound samples in which no bacteria were detected using the standard culture method, according to a study published in the July issue of the Journal of Clinical Microbiology. One of the study’s key findings, the researchers say, is that the assay detected bacteria, commonly seen with hospital-related infections, which were associated with wounds that did not heal successfully. The technology combines bioinformatics with a microarray that in its current iteration has […]
Developers assess many considerations when making the determination of the size of a multiplex panel: comprehensiveness versus actionability, efficiency versus sensitivity. While targeted, moderately sized solutions are likely ideal for most common conditions, researchers at Lawrence Livermore National Laboratory (California) are developing a super assay for global disease surveillance and for instances when there is not a suspected pathogen. The Lawrence Livermore Microbial Detection Array (LLMDA) is capable of detecting virtually any microbe that has been sequenced, with results in 24 hours.
The researchers see configuration of the assay as possible for a wide range of clinical applications. It has demonstrated success, for instance, in detecting bacterial pathogens in the wounds of U.S. soldiers. The LLMDA was able to detect at least one bacterial pathogen in roughly one-third of wound samples in which no bacteria were detected using the standard culture method, according to a study published in the July issue of the Journal of Clinical Microbiology. One of the study’s key findings, the researchers say, is that the assay detected bacteria,
commonly seen with hospital-related infections, which were associated with wounds that did not heal successfully.
The technology combines bioinformatics with a microarray that in its current iteration has probes for about 8,100 microorganisms, including 3,855 bacteria and 3,856 viruses (as well as fungal targets). The researchers say several microarray configurations are possible on a single slide, including a single square array containing all 360,000 probes, four arrays of 72,000 probes each, or for human clinical use, 12 arrays on one slide, each with 135,000 probes.
Compared to polymerase chain reaction and next-generation sequencing, LLMDA is midrange in cost, processing time, and sensitivity, the Livermore researchers say. Crystal Jaing, Ph.D., a group leader in applied genomics and part of the LLMDA team, acknowledges that while the group believes the array could be applied clinically in cases of burns with large surface areas, people injured by trauma, or people with diabetic ulcers, there are reimbursement and regulatory hurdles given the lack of a precedent for such a comprehensive test.
Jaing tells DTET that right now the turnaround takes 24 hours, which is still “reasonable” for clinical use, but can be shortened by adding automation to the test. Future iterations of the assay could also incorporate databases containing virulence and resistance profiles of pathogens, which would provide “very rich information.”
Takeaway: The LLMDA is a supersized microarray capable of detecting virtually any microbe that has been sequenced. Its developers are finding it to have clinical utility but acknowledge potential regulatory and reimbursement hurdles in the near term.
