Molecular probes designed to spot minute amounts of pathogens in biological samples may aid clinical laboratories’ speed-to-answer
Driven to find a better way to isolate minute samples of pathogens from among high-volumes of other biological organisms, researchers at Canada’s McMaster University in Hamilton, Ontario, have unveiled a bioinformatics algorithm which they claim shortens time-to-answer and speeds diagnosis of deadly diseases.
Two disease pathogens the researchers specifically targeted in their study are responsible for sepsis and SARS-CoV-2, the coronavirus causing COVID-19. Clinical laboratories would welcome a technology which both shortens time-to-answer and improves diagnostic accuracy, particularly for pathogens such as sepsis and SARS-CoV-2.
Their design of molecular probes that target the genomic sequences of specific pathogens can enable diagnosticians and clinical laboratories to spot extremely small amounts of viral and bacterial pathogens in patients’ biological samples, as well as in the environment and wildlife.
“There are thousands of bacterial pathogens and being able to determine which one is present in a patient’s blood sample could lead to the correct treatment faster when time is very important,” Zachery Dickson, a lead author of the study, told Brighter World. Dickson is a bioinformatics PhD candidate in the Department of Biology at McMaster University. “The probe makes identification much faster, meaning we could potentially save people who might otherwise die,” he added.
Sepsis is a life-threatening response to infection that leads to organ failure, tissue damage, and death in hospitals worldwide. According to Sepsis Alliance, about 30% of people diagnosed with severe sepsis will die without quick and proper treatment. Thus, a “shortcut” to identifying sepsis in its early stages may well save many lives, the McMaster researchers noted.
And COVID-19 has killed millions. Such a tool that identifies sepsis and SARS-CoV-2 in minute biological samples would be a boon to hospital medical laboratories worldwide.
Is Bioinformatics ‘Shortcut’ Faster than PCR Testing?
The researchers say their probes enable a shortcut to detection—even in an infection’s early stages—by “targeting, isolating, and identifying the DNA sequences specifically and simultaneously.”
The probes’ design makes possible simultaneous targeted capture of diverse metagenomics targets, Biocompare explained.
But is it faster than PCR (polymerase chain reaction) testing?
The McMaster scientists were motivated by the “challenges of low signal, high background, and uncertain targets that plague many metagenomic sequencing efforts,” they noted in their paper.
They pointed to challenges posed by PCR testing, a popular technique used for detection of sepsis pathogens as well as, more recently, for SARS-CoV-2, the coronavirus causing COVID-19.
“The (PCR) technique relies on primers that bind to nucleic acid sequences specific to an organism or group of organisms. Although capable of sensitive, rapid detection and quantification of a particular target, PCR is limited when multiple loci are targeted by primers,” the researchers wrote in Cell Reports Methods.
According to LabMedica, “A wide array of metagenomic study efforts are hampered by the same challenge: low concentrations of targets of interest combined with overwhelming amounts of background signal. Although PCR or naive DNA capture can be used when there are a small number of organisms of interest, design challenges become untenable for large numbers of targets.”
Detecting Pathogens Faster, Cheaper, and More Accurately
As part of their study, researchers tested two probe sets:
one to target bacterial pathogens linked to sepsis, and
another to detect coronaviruses including SARS-CoV-2.
They were successful in using the probes to capture a variety of pathogens linked to sepsis and SARS-CoV-2.
“We validated HUBDesign by generating probe sets targeting the breadth of coronavirus diversity, as well as a suite of bacterial pathogens often underlying sepsis. In separate experiments demonstrating significant, simultaneous enrichment, we captured SARS-CoV-2 and HCoV-NL63 [Human coronavirus NL 63] in a human RNA background and seven bacterial strains in human blood. HUBDesign has broad applicability wherever there are multiple organisms of interest,” the researchers wrote in Cell Reports Methods.
The findings also have implications to the environment and wildlife, the researchers noted.
Of course, more research is needed to validate the tool’s usefulness in medical diagnostics. The McMaster University researchers intend to improve HUBDesign’s efficiency but note that probes cannot be designed for unknown targets.
Nevertheless, the advanced application of novel technologies to diagnose of sepsis, which causes 250,000 deaths in the US each year, according to the federal Centers for Disease Control and Prevention, is a positive development worth watching.
The McMaster scientists’ discoveries—confirmed by future research and clinical studies—could go a long way toward ending the dire effects of sepsis as well as COVID-19. That would be a welcome development, particularly for hospital-based laboratories.
Several young companies hope to expand the direct-to-consumer test market by introducing new diagnostic tests to serve the women’s health market
Providing women with at-home lab test kits is the goal of a growing class of start-up companies that are bringing to market consumer test kits for a range of health conditions common to women. These companies believe they can shift a substantial volume of such testing away from the nation’s medical laboratories.
Moreover, diagnostic startups that develop at-home direct-to-consumer (DTC) clinical laboratory genetic tests have been hot commodities among venture capitalists and other healthcare investors willing to put tens of millions of dollars into these new firms. The New York Times observed that, until recently, women’s healthcare needs have rarely been the focus of new diagnostic testing companies, but that the situation may be changing.
“Femtech” (short for female technology) products and services that address the health and wellness needs of women is the new buzz word in healthcare. It describes female-focused diagnostic startups aiming at vaginal health and other medical issues that go beyond reproductive health concerns.
This, however, is a dual-edged sword for clinical laboratory leaders. Growth in this segment could lead to new diagnostics tests that boost a medical lab’s bottom line or, conversely, it could reduce revenue as patients self-diagnose urinary tract infections (UTIs), yeast infections, and other conditions through at-home DTC testing.
Vaginal Microbiome At-home Clinical Laboratory Tests in High Demand
One area in particular drawing the attention of several female-led startups is vaginal health. According to an article in Vogue, test developers Juno Bio and Evvy are leading the way with at-home vaginal microbiome tests that let users “know what’s up down there.”
New York City-based Evvy ($129 for a single test or $99 each for four tests per year) uses metagenomic sequencing to identify the bacteria and fungi present in the vaginal microbiome. This information helps customers to understand their levels of protective and disruptive bacteria, which can be associated with everything from reoccurring infections and transmission of sexually transmitted diseases to infertility.
London-based Juno Bio ($149 per test) does not disclose its testing method. It does, however, provide users with a “full vaginal microbiome profile.” The profile is accessed online within a “few days” of returning the vaginal swab sample to the company’s clinical laboratory.
Both companies note that their tests are intended to be used for wellness purposes and are not meant to diagnose or treat disease or substitute for a physician’s consultation.
Gynecologist Oluwatosin Goje, MD, MSCR, FACOG, a reproductive infectious disease specialist at Cleveland Clinic, believes the availability of at-home vaginal microbiome testing will provide valuable information to both women and their doctors.
“It’s a powerful tool because it enables us to look at the entire microbial community through metagenomics and decipher how the overall composition might be affecting symptoms and infections, as well as determine the best treatment pathway,” Goje, an Evvy Medical Advisor, told Vogue. “Understanding the complete vaginal microbiome allows us to be good antibiotic stewards and only administer antibiotics when needed. Patients can also retest remotely to understand how antibiotics and other treatments impacted their vaginal microbiome.”
Removing the Discomfort of Shopping for Women’s Health Products
Jamie Norwood and Cynthia Plotch, co-founders of Stix, a supplier of women’s health products and education, launched their company with a product line of at-home pregnancy and ovulation tests. They have since expanded their offerings to include urinary tract infection (UTI) and yeast infection testing and treatments.
“You can test, relieve, treat, and help prevent future infections—all from the comfort of your own home,” Norwood, told Vogue. She emphasized that this is the kind of experience healthcare consumers are demanding in today’s ever-growing direct-to-consumer clinical laboratory testing landscape. “Agonizing over confusing over-the-counter products in the drugstore aisles, or bending over backwards to pick up a prescription at the pharmacy, just isn’t cutting it for Millennial and Gen Z consumers.”
According to WebMD, yeast infections are a chronic problem for many women. While 75% of women will get at least one yeast infection in their lifetime, up to 8% get more than four a year. In addition, the federal Centers for Disease Control and Prevention (CDC) points out that bacterial vaginosis is the most common vaginal condition in females ages 15-44.
Lola Priego, is CEO and founder of blood test company Base, which sells at-home saliva and finger-prick blood tests to monitor hormone levels, vitamin levels, neurotransmitters, and blood cell markers to improve everything from sleep and diet to sex drive. She predicts direct-to-consumer testing will become as common as fitness watches.
“Eventually, at-home lab testing will be another readily-used tool, similar to your health-tracking wearables, that helps us optimize for a well-rounded healthy lifestyle in a more individualized way,” Priego told Vogue.
Femtech a ‘Significantly Underdeveloped’ Market
In its latest Analyst Note, financial data firm PitchBook maintained that the market for female health products is poised for growth. TechCrunch, which reviewed PitchBook’s analysis of female-focused health products, reported that Femtech remains a “significantly underdeveloped” slice of health-tech spending.
While women spend an estimated $500 billion annually on medical expenses, only 4% of research and development money is targeted at women’s health, PitchBook noted. In its analysis, Pitchbook predicted the global market for female-focused health products will reach $3 billion by the end of 2030. By comparison, that segment of the healthcare market totaled $820.6 million last year.
“While we still view Femtech as a niche industry, we believe secular drivers could help propel new growth opportunities in the space,” PitchBook analysts wrote. “These include the increasing representation of women in the venture-backed technology community, rising awareness and acceptance of women’s health issues, and the growing prevalence of infectious diseases among women in some countries in Africa and Asia.
“Furthermore, while the majority of Femtech products have traditionally focused on reproductive health, we believe new approaches to women’s health research will help open the door to new products and services,” they noted.
Clinical laboratory leaders will be wise to carefully watch the growth of at-home DTC tests and products targeted at female healthcare consumers since fewer trips to physicians’ offices may mean fewer test orders for local labs.
At the same time, the opportunity exists for innovative pathologists and lab managers to develop digital services that allow consumers who are self-testing to store their home-test results in the lab’s app. They can then receive relevant insights from clinical pathologists to help them fully understand the implications of the test results.
Newly combined digital pathology, artificial intelligence (AI), and omics technologies are providing anatomic pathologists and medical laboratory scientists with powerful diagnostic tools
Add “spatial transcriptomics” to the growing list of “omics” that have the potential to deliver biomarkers which can be used for earlier and more accurate diagnoses of diseases and health conditions. As with other types of omics, spatial transcriptomics might be a new tool for surgical pathologists once further studies support its use in clinical care.
Among this spectrum of omics is spatial transcriptomics, or ST for short.
Spatial Transcriptomics is a groundbreaking and powerful molecular profiling method used to measure all gene activity within a tissue sample. The technology is already leading to discoveries that are helping researchers gain valuable information about neurological diseases and breast cancer.
Marriage of Genetic Imaging and Sequencing
Spatial transcriptomics is a term used to describe a variety of methods designed to assign cell types that have been isolated and identified by messenger RNA (mRNA), to their locations in a histological section. The technology can determine subcellular localization of mRNA molecules and can quantify gene expression within anatomic pathology samples.
In “Spatial: The Next Omics Frontier,” Genetic Engineering and Biotechnology News (GEN) wrote, “Spatial transcriptomics gives a rich, spatial context to gene expression. By marrying imaging and sequencing, spatial transcriptomics can map where particular transcripts exist on the tissue, indicating where particular genes are expressed.”
In an interview with Technology Networks, George Emanuel, PhD, co-founder of life-science genomics company Vizgen, said, “Spatial transcriptomic profiling provides the genomic information of single cells as they are intricately spatially organized within their native tissue environment.
“With techniques such as single-cell sequencing, researchers can learn about cell type composition; however, these techniques isolate individual cells in droplets and do not preserve the tissue structure that is a fundamental component of every biological organism,” he added.
“Direct spatial profiling the cellular composition of the tissue allows you to better understand why certain cell types are observed there and how variations in cell state might be a consequence of the unique microenvironment within the tissue,” he continued. “In this way, spatial transcriptomics allows us to measure the complexity of biological systems along the axes that are most relevant to their function.”
According to 10x Genomics, “spatial transcriptomics utilizes spotted arrays of specialized mRNA-capturing probes on the surface of glass slides. Each spot contains capture probes with a spatial barcode unique to that spot.
“When tissue is attached to the slide, the capture probes bind RNA from the adjacent point in the tissue. A reverse transcription reaction, while the tissue is still in place, generates a cDNA [complementary DNA] library that incorporates the spatial barcodes and preserves spatial information.
“Each spot contains approximately 200 million capture probes and all of the probes in an individual spot share a barcode that is specific to that spot.”
“The highly multiplexed transcriptomic readout reveals the complexity that arises from the very large number of genes in the genome, while high spatial resolution captures the exact locations where each transcript is being expressed,” Emanuel told Technology Networks.
Spatial Transcriptomics for Breast Cancer and Neurological Diagnostics
In that paper, the authors wrote “we envision that in the coming years we will see simplification, further standardization, and reduced pricing for the ST protocol leading to extensive ST sequencing of samples of various cancer types.”
Spatial transcriptomics is also being used to research neurological conditions and neurodegenerative diseases. ST has been proven as an effective tool to hunt for marker genes for these conditions as well as help medical professionals study drug therapies for the brain.
“You can actually map out where the target is in the brain, for example, and not only the approximate location inside the organ, but also in what type of cells,” Malte Kühnemund, PhD, Director of Research and Development at 10x Genomics, told Labiotech.eu. “You actually now know what type of cells you are targeting. That’s completely new information for them and it might help them to understand side effects and so on.”
The field of spatial transcriptomics is rapidly moving and changing as it branches out into more areas of healthcare. New discoveries within ST methodologies are making it possible to combine it with other technologies, such as Artificial Intelligence (AI), which could lead to powerful new ways oncologists and anatomic pathologists diagnose disease.
“I think it’s going to be tricky for pathologists to look at that data,” Kühnemund said. “I think this will go hand in hand with the digital pathology revolution where computers are doing the analysis and they spit out an answer. That’s a lot more precise than what any doctor could possibly do.”
Spatial transcriptomics certainly is a new and innovative way to look at tissue biology. However, the technology is still in its early stages and more research is needed to validate its development and results.
Nevertheless, this is an opportunity for companies developing artificial intelligence tools for analyzing digital pathology images to investigate how their AI technologies might be used with spatial transcriptomics to give anatomic pathologists a new and useful diagnostic tool.
The UE study sheds light on the types of bacteria in
wastewater that goes down hospital pipes to sewage treatment plants. The study
also revealed that not all infectious agents are killed after passing through
waste treatment plants. Some bacteria with antimicrobial (or antibiotic)
resistance survive to enter local food sources.
The scientists concluded that the amount of AMR genes found
in hospital wastewater was linked to patients’ length-of-stays and consumption
of antimicrobial resistant bacteria while in the hospital.
In a paper the University of Edinburgh published on medRxiv, the researchers wrote: “There was a higher abundance of antimicrobial-resistance genes in the hospital wastewater samples when compared to Seafield community sewage works … Sewage treatment does not completely eradicate antimicrobial-resistance genes and thus antimicrobial-resistance genes can enter the food chain through water and the use of [processed] sewage sludge in agriculture. As hospital wastewater contains inpatient bodily waste, we hypothesized that it could be used as a representation of inpatient community carriage of antimicrobial resistance and as such may be a useful surveillance tool.”
Additionally, they wrote, “Using metagenomics to identify
the full range of AMR genes in hospital wastewater could represent a useful
surveillance tool to monitor hospital AMR gene outflow and guide environmental
policy on AMR.”
Antibiotic resistance occurs when bacteria change in response to medications to prevent and treat bacterial infections, according to a World Health Organization (WHO) fact sheet. The CDC estimates that more than 23,000 people die annually from two million antibiotic-resistance infections.
Wastewater, the UE scientists suggest, should not go to
waste. It could be leveraged to improve hospitals’ detection of patients with antimicrobial
resistance, as well as to boost environment antimicrobial-resistance polices.
They used metagenomics (the study of genetic material
relative to environmental samples) to compare the antimicrobial-resistance
genes in hospital wastewater against wastewater from community sewage
The UE researchers:
First collected samples over a 24-hour period from various areas in a tertiary hospital;
They then obtained community sewage samples from various locations around Seafield, Scotland;
Antimicrobial-resistance genes increased with longer length of patient stays, which “likely reflects transmission amongst hospital inpatients,” researchers noted.
Fey suggests that further research into using sequencing
technology to monitor patients is warranted.
“I think that monitoring each patient and sequencing their
bowel flora is more likely where we’ll be able to see if there’s a significant
carriage of antibiotic-resistant organisms,” Fey told MedPage Today. “In
five years or so, sequencing could become so cheap that we could monitor every
patient like that.”
Fey was not involved in the University of Edinburgh
Given the rate at which AMR bacteria spreads, finding antibiotic-resistance
genes in hospital wastewater may not be all that surprising. Still, the University
of Edinburgh study could lead to cost-effective ways to test the genes of
bacteria, which then could enable researchers to explore different sources of
infection and determine how bacteria move through the environment.
And, perhaps most important, the study suggests clinical
laboratories have many opportunities to help eliminate infections and slow
antibiotic resistance. Microbiologists can help move their organizations forward
too, along with infection control colleagues.