New technology could enable genetic scientists to identify antibiotic resistant genes and help physicians choose better treatments for genetic diseases
Genomic scientists at the Icahn School of Medicine at Mount Sinai Medical Center in New York City have developed what they call a “smart tweezer” that enables researchers to isolate a single bacterium from a patient’s microbiome in preparation for genetic sequencing. Though primarily intended for research purposes, the new technology could someday be used by clinical laboratories and microbiologists to help physicians diagnose chronic disease and choose appropriate genetic therapies.
The researchers designed their new technology—called mEnrich-seq—to improve the effectiveness of research into the complex communities of microorganisms that reside in the microbiomes within the human body. The discovery “ushers in a new era of precision in microbiome research,” according to a Mount Sinai Hospital press release.
“Imagine you’re a scientist who needs to study one particular type of bacteria in a complex environment. It’s like trying to find a needle in a large haystack,” said the study’s senior author Gang Fang, PhD (above), Professor of Genetics and Genomic Sciences at Icahn School of Medicine at Mount Sinai Medical Center, in a press release. “mEnrich-seq essentially gives researchers a ‘smart tweezer’ to pick up the needle they’re interested in,” he added. Might smart tweezers one day be used to help physicians and clinical laboratories diagnose and treat genetic diseases? (Photo copyright: Icahn School of Medicine.)
Addressing a Technology Gap in Genetic Research
Any imbalance or decrease in the variety of the body’s microorganisms can lead to an increased risk of illness and disease.
In researching the microbiome, many scientists “focus on studying specific types of bacteria within a sample, rather than looking at each type of bacteria present,” the press release states. The limitation of this method is that a specific bacterium is just one part of a complicated environment that includes other bacteria, viruses, fungi and host cells, each with their own unique DNA.
“mEnrich-seq effectively distinguishes bacteria of interest from the vast background by exploiting the ‘secret codes’ written on bacterial DNA that bacteria use naturally to differentiate among each other as part of their native immune systems,” the press release notes. “This new strategy addresses a critical technology gap, as previously researchers would need to isolate specific bacterial strains from a given sample using culture media that selectively grow the specific bacterium—a time-consuming process that works for some bacteria, but not others. mEnrich-seq, in contrast, can directly recover the genome(s) of bacteria of interest from the microbiome sample without culturing.”
Isolating Hard to Culture Bacteria
To conduct their study, the Icahn researchers used mEnrich-seq to analyze urine samples taken from three patients with urinary tract infections (UTIs) to reconstruct Escherichia coli (E. Coli) genomes. They discovered their “smart tweezer” covered more than 99.97% of the genomes across all samples. This facilitated a comprehensive examination of antibiotic-resistant genes in each genome. They found mEnrich-seq had better sensitivity than standard study methods of the urine microbiome.
They also used mEnrich-seq to selectively examine the genomes of Akkermansia muciniphila (A. muciniphila), a bacterium that colonizes the intestinal tract and has been shown to have benefits for obesity and Type 2 diabetes as well as a response to cancer immunotherapies.
“Akkermansia is very hard to culture,” Fang told GenomeWeb. “It would take weeks for you to culture it, and you need special equipment, special expertise. It’s very tedious.”
mEnrich-seq was able to quickly segregate it from more than 99.7% of A. muciniphila genomes in the samples.
Combatting Antibiotic Resistance Worldwide
According to the press release, mEnrich-seq could potentially be beneficial to future microbiome research due to:
Cost-Effectiveness: It offers a more economical approach to microbiome research, particularly beneficial in large-scale studies where resources may be limited.
Broad Applicability: The method can focus on a wide range of bacteria, making it a versatile tool for both research and clinical applications.
Medical Breakthroughs: By enabling more targeted research, mEnrich-seq could accelerate the development of new diagnostic tools and treatments.
“One of the most exciting aspects of mEnrich-seq is its potential to uncover previously missed details, like antibiotic resistance genes that traditional sequencing methods couldn’t detect due to a lack of sensitivity,” Fang said in the news release. “This could be a significant step forward in combating the global issue of antibiotic resistance.”
More research and clinical trials are needed before mEnrich-seq can be used in the medical field. The Icahn researchers plan to refine their novel genetic tool to improve its efficiency and broaden its range of applications. They also intend to collaborate with physicians and other healthcare professionals to validate how it could be used in clinical environments.
Should all this come to pass, hospital infection control teams, clinical laboratories, and microbiology labs would welcome a technology that would improve their ability to detect details—such as antibiotic resistant genes—that enable a faster and more accurate diagnosis of a patient’s infection. In turn, that could contribute to better patient outcomes.
The ASBMB story notes that nanopore technology depends on differences in charges on either side of the membrane to force DNA or RNA through the hole. This is one reason why proteins pose such a challenge.
“Think of a cell as a miniature city, with proteins as its inhabitants. Each protein-resident has a unique identity, its own characteristics, and function. If there was a database cataloging the fingerprints, job profiles, and talents of the city’s inhabitants, such a database would undoubtedly be invaluable!” said Behzad Mehrafrooz, PhD (above), Graduate Research Assistant at University of Illinois at Urbana-Champaign in an article he penned for the university website. This research should be of interest to the many clinical laboratories that do protein testing. (Photo copyright: University of Illinois.)
How the Maglia Process Works
In a Groningen University news story, Maglia said protein is “like cooked spaghetti. These long strands want to be disorganized. They do not want to be pushed through this tiny hole.”
His technique, developed in collaboration with researchers at the University of Rome Tor Vergata, uses electrically charged ions to drag the protein through the hole.
“We didn’t know whether the flow would be strong enough,” Maglia stated in the news story. “Furthermore, these ions want to move both ways, but by attaching a lot of charge on the nanopore itself, we were able to make it directional.”
The researchers tested the technology on what Maglia described as a “difficult protein” with many negative charges that would tend to make it resistant to flow.
“Previously, only easy-to-thread proteins were analyzed,” he said in the news story. “But we gave ourselves one of the most difficult proteins as a test. And it worked!”
Maglia now says that he intends to commercialize the technology through a new startup called Portal Biotech.
Detecting Post-Translational Modifications in the UK
In another recent study, researchers at the University of Oxford reported that they have adapted nanopore technology to detect post-translational modifications (PTMs) in protein chains. The term refers to changes made to proteins after they have been transcribed from DNA, explained an Oxford news story.
“The ability to pinpoint and identify post-translational modifications and other protein variations at the single-molecule level holds immense promise for advancing our understanding of cellular functions and molecular interactions,” said contributing author Hagan Bayley, PhD, Professor of Chemical Biology at University of Oxford, in the news story. “It may also open new avenues for personalized medicine, diagnostics, and therapeutic interventions.”
Bayley is the founder of Oxford Nanopore Technologies, a genetic sequencing company in the UK that develops and markets nanopore sequencing products.
The news story notes that the new technique could be integrated into existing nanopore sequencing devices. “This could facilitate point-of-care diagnostics, enabling the personalized detection of specific protein variants associated with diseases including cancer and neurodegenerative disorders,” the story states.
In another recent study, researchers at the University of Washington reported that they have developed their own method for protein sequencing with nanopore technology.
“This opens up the possibility for barcode sequencing at the protein level for highly multiplexed assays, PTM monitoring, and protein identification!” Motone wrote.
Single-cell proteomics, enabled by nanopore protein sequencing technology, “could provide higher sensitivity and wider throughput, digital quantification, and novel data modalities compared to the current gold standard of protein MS [mass spectrometry],” they wrote. “The accessibility of these tools to a broader range of researchers and clinicians is also expected to increase with simpler instrumentation, less expertise needed, and lower costs.”
There are approximately 20,000 human genes. However, there are many more proteins. Thus, there is strong interest in understanding the human proteome and the role it plays in health and disease.
Technology that makes protein testing faster, more accurate, and less costly—especially with a handheld analyzer—would be a boon to the study of proteomics. And it would give clinical laboratories new diagnostic tools and bring some of that testing to point-of-care settings like doctor’s offices.
Project should provide treasure-trove of molecular information on human protein and lead to development of new biomarkers for use in clinical laboratory tests and personalized medicine
Scientists participating in the ProteomeTools project have announced the synthesis of a library of more than 330,000 peptides representing essentially all canonical proteins of the human proteome.
Translating Human Proteome into Molecular and Digital Tools
The ProteomeTools project is “a joint effort of TUM, JPT Peptide Technologies, SAP SE, and Thermo Fisher Scientific … dedicated to translating the human proteome into molecular and digital tools for drug discovery, personalized medicine, and life science research.” Over the course of the project, 1.4 million synthetic peptides covering essentially all human gene products will be synthesized and analyzed using multimodal liquid chromatography-tandem mass spectrometry (LC-MS/MS).
ProteomeTools published their first paper, “Building ProteomeTools Based on a Complete Synthetic Human Proteome,” which detailed their work in Nature Methods.
“ProteomeTools was started as a collaborative effort bringing together academic and industrial partners to make important contributions to the field of proteomics. It is gratifying to see that this work is now producing a wealth of significant results,” stated TUM researcher Bernhard Kuster, PhD, one of the leaders of the effort and senior author on the Nature Methods paper, in a TUM news release.
Thousands of New Biomarkers for Clinical Laboratories, and More!
Kuster discussed the significance of the consortium’s work in an article published in Genome Web, which described ProteomeTools as “a resource that provides the proteomics community with a set of established standards against which it can compare experimental data.”
“In proteomics today, we are doing everything by inference,” Kuster stated to Genome Web. “We have a tandem mass spectrum and we use a computer algorithm to match it to a peptide sequence that [is generated] in silico to simulate what their spectrum might look like without us actually knowing what it looks like. That is a very fundamental problem.”
Bernhard Kuster, PhD (above center), of the Technical University of Munich (TUM), led a team of researchers from the ProteomeTools project who completed a tandem mass spectrometry analysis of more than 330,000 synthetic tryptic peptides representing essentially all of the canonical human gene products. The resource eventually will cover all one million peptides. (Photo copyright: Andreas Heddergott/TUM.)
In the Genome Web article, Kuster provides an example of how researchers could use the information developed by ProteomeTools, noting it could be useful for confirming peptide identification in borderline cases. “Because the spectra for these synthetic peptides are available to everyone, you could look up a protein or peptide ID that you find exciting, but where the [experimental] data might not totally convince you as to whether it is true or not,” he explained.
Kuster also states that he believes the resource has the potential to allow “the field to move away from conventional database searching methods toward a spectral matching approach.”
The TUM news release notes that the ProteomeTools project “will generate a further one million peptides and corresponding spectra with a focus on splice variants, cancer mutations, and post-translational modifications, such as phosphorylation, acetylation, and ubiquitinylation.” The end result could be a treasure-trove of molecular information on the human proteome and development of thousands of new biomarkers for clinical use for therapeutic drugs, and more.
“Representing the human proteome by tandem mass spectra of synthetic peptides alleviates some of the current issues with protein identification and quantification. The libraries of peptides and spectra now allow us to develop new and improve upon existing hardware, software, workflows, and reagents for proteomics. Making all the data available to the public provides a wonderful opportunity to exploit this resource beyond what a single laboratory can do. We are now reaching out to the community to suggest interesting sets of peptides to make and measure as well as to create LC-MS/MS data on platforms not available to the ProteomeTools consortium,” Kuster stated in the TUM news release.
All data from the ProteomeTools project is available at the ProteomeXchange Consortium. Pathologists and clinical laboratory professionals working to develop new assays will find it to be a valuable resource.
Breakthrough method could provide pathologists with a less expensive alternative to high-priced super-resolution microscopes or often-imprecise microscopy software
Intriguing new research has the potential to “turbocharge” the standard medical laboratory microscope in ways that create a “super-vision” capability. This would give pathologists and medical researchers an inexpensive alternative to high-priced super-resolution microscopes or often-imprecise microscopy software.
