Dionne is senior author of a new study in the journal Nano Letters detailing an ingenious technique her team has actually established that could lead to faster (nearly instant), low-cost, and more precise microbial assays of virtually any fluid one might wish to check for microorganisms.
Standard culturing techniques still in usage today can take hours if not days to finish. A tuberculosis culture takes 40 days, Dionne said. The brand-new test can be performed in minutes and holds the promise of better and faster diagnoses of infection, improved usage of antibiotics, more secure foods, enhanced ecological tracking, and much faster drug advancement, states the group.
Information of the printed dots on a gold-coated slide (a) where incorrect coloring in the close-up of a single dot shows red blood calls in red and Staphylococcus epidermidis germs in blue. The researchers also printed onto an agar-coated slide (b) to demonstrate how the dots fare under incubation. Credit: Fareeha Safir
Old dogs, brand-new techniques
The development is not that bacteria display these spectral finger prints, a truth that has been known for decades, however in how the team has had the ability to expose those spectra amid the blinding selection of light reflecting from each sample.
” Not only does each kind of germs show distinct patterns of light however essentially every other molecule or cell in a given sample does too,” said first author Fareeha Safir, a Ph.D. student in Dionnes lab. “Red blood cells, leukocyte, and other components in the sample are returning their own signals, making it hard if not difficult to differentiate the microbial patterns from the sound of other cells.”
A milliliter of blood– about the size of a raindrop– can consist of billions of cells, just a few of which may be microorganisms. The team needed to discover a method to separate and magnify the light showing from the bacteria alone. To do that, they ventured along a number of unexpected scientific tangents, integrating a four-decade-old technology obtained from computing– the inkjet printer– and two innovative innovations of our time– nanoparticles and expert system.
” The secret to separating bacterial spectra from other signals is to separate the cells in extremely little samples. We utilize the principles of inkjet printing to print thousands of small dots of blood instead of questioning a single big sample,” discussed co-author Butrus “Pierre” Khuri-Yakub, a professor emeritus of electrical engineering at Stanford who assisted develop the initial inkjet printer in the 1980s.
” But you cant just get an off-the-shelf inkjet printer and add blood or wastewater,” Safir stressed. To prevent challenges in dealing with biological samples, the scientists modified the printer to put samples to paper using acoustic pulses. Each dot of printed blood is then just 2 trillionths of a liter in volume– more than a billion times smaller than a raindrop. At that scale, the droplets are so small they might hold simply a few dozen cells.
In addition, the scientists infused the samples with gold nanorods that connect themselves to bacteria, if present, and act like antennas, drawing the laser light towards the germs and enhancing the signal some 1500 times its unenhanced strength. Appropriately separated and amplified, the bacterial spectra stick out like clinical aching thumbs.
The final piece of the puzzle is making use of device finding out to compare the numerous spectra reflecting from each printed dot of fluid to spot the obvious signatures of any bacteria in the sample.
” Its an ingenious service with the potential for life-saving impact. We are now excited for commercialization opportunities that can help redefine the requirement of bacterial detection and single-cell characterization,” stated senior co-author Amr Saleh, a previous postdoctoral scholar in Dionnes laboratory and now a professor at Cairo University.
Catalyst for collaboration
This sort of cross-disciplinary partnership is a trademark of the Stanford tradition in which specialists from apparently disparate fields bring their varying know-how to bear to solve longstanding obstacles with social effect.
This specific method was hatched throughout a lunchtime conference at a café on campus and, in 2017, was among the first recipients of a series of $ 3 million grants dispersed by Stanfords Catalyst for Collaborative Solutions. Driver grants are specifically targeted at inspiring interdisciplinary risk-taking and cooperation among Stanford researchers in high-reward fields such as healthcare, the environment, autonomy, and security.
While this technique was created and perfected utilizing samples of blood, Dionne is similarly positive that it can be used to other sorts of fluids and target cells beyond bacteria, like screening drinking water for purity or maybe finding infections faster, more precisely, and at a lower expense than present approaches.
Referral: “Combining Acoustic Bioprinting with AI-Assisted Raman Spectroscopy for High-Throughput Identification of Bacteria in Blood” by Fareeha Safir, Nhat Vu, Loza F. Tadesse, Kamyar Firouzi, Niaz Banaei, Stefanie S. Jeffrey, Amr. A. E. Saleh, Butrus (Pierre) T. Khuri-Yakub and Jennifer A. Dionne, 1 March 2023, Nano Letters.DOI: 10.1021/ acs.nanolett.2 c03015.
This research was moneyed by the Stanford Catalyst for Collaborative Solutions, the Chan Zuckerberg Biohub Investigator Program, the NIH-NCATS-CTSA, the Gates Foundation, the National Science Foundation, the NIH New Innovator Award, and from seed funds from the Stanford Center for Innovation in Global Health. Part of this work was carried out at the Stanford Nano Shared Facilities (SNSF) and the Soft & & Hybrid Materials Facility (SMF), which are supported by the National Science Foundation and National Nanotechnology Coordinated Infrastructure.
A derivative of the Stanford University logo printed from beads consisting of a 1:1 mix of Staphylococcus epidermidis germs and mouse red blood cells (RBCs) onto a gold-coated slide. Details of the printed dots on a gold-coated slide (a) where incorrect coloring in the close-up of a single dot reveals red blood calls in red and Staphylococcus epidermidis bacteria in blue. A milliliter of blood– about the size of a raindrop– can include billions of cells, just a few of which might be microbes. The team had to discover a method to separate and magnify the light reflecting from the germs alone. Each dot of printed blood is then just 2 trillionths of a liter in volume– more than a billion times smaller than a raindrop.
A derivative of the Stanford University logo printed from beads containing a 1:1 mixture of Staphylococcus epidermidis germs and mouse red cell (RBCs) onto a gold-coated slide. Droplets were printed utilizing 147 MHz acoustic transducer. Credit: Fareeha Safir
A creative combination of AI-assisted imaging with the innovation of an outdated inkjet printer results in a more efficient and economical technique for detecting bacteria in substances such as blood and wastewater.
By shining a laser on a drop of blood, wastewater, or mucus, the reflection of the light can be examined to properly recognize the existence of bacteria in the sample.
” We can learn not just that bacteria are present, but specifically which germs are in the sample– E. coli, Staphylococcus, Streptococcus, Salmonella, anthrax, and more,” said Jennifer Dionne, an associate teacher of materials science and engineering and, by courtesy, of radiology at Stanford University. “Every microorganism has its own special optical fingerprint. Its like the proteomic and hereditary code doodled in light.”