As molecular threats evolve, so must the way we prepare for them.

In this month’s edition of the BioPathogenix Molecular Brief, we spotlight the high-priority pathogens demanding global attention, celebrate overlooked contributors to one of the most pivotal experiments in genetic science, and honor the women who helped turn PCR from concept to cornerstone.

From Candida auris and emerging coronaviruses to the legacy of Avery, MacLeod, and McCarty, this issue connects history, innovation, and actionable insight — all with the goal of equipping today’s labs for tomorrow’s challenges.

👇 Keep reading for this month’s pathogen intelligence, molecular milestones, and who’s shaping the next era of detection and discovery.

The Experiment That Changed Everything: Avery, MacLeod, and McCarty

In 1944, Oswald Avery, Colin MacLeod, and Maclyn McCarty conducted a groundbreaking experiment that identified deoxyribonucleic acid (DNA) as the carrier of genetic information, fundamentally altering our understanding of heredity and laying the foundation for modern molecular biology.

Background: The Quest for Genetic Material

Prior to this discovery, scientists were uncertain about the molecular basis of inheritance. Proteins, with their structural complexity and functional diversity, were considered the prime candidates for genetic material.

This assumption was challenged by Frederick Griffith's 1928 experiment, which demonstrated that a "transforming principle" from a virulent strain of Streptococcus pneumoniae could convert a non-virulent strain into a virulent one--however, the nature of this transforming principle remained unidentified.

The Experiment: Unveiling DNA as the Transforming Principle

Avery, MacLeod, and McCarty aimed to isolate and identify the chemical nature of Griffith's transforming principle. They focused on S. pneumoniae bacteria, known for causing pneumonia. The experiment involved the following steps:

Preparation of Bacterial Extracts: They created extracts from heat-killed virulent (S strain) bacteria, ensuring that all cellular components were released into solution.

Selective Degradation: To determine which macromolecule was responsible for transformation, they treated these extracts with specific enzymes:

Proteases: Enzymes that degrade proteins. Treatment with proteases did not eliminate the transforming ability.

Ribonuclease (RNase): Enzyme that degrades RNA. Treatment with RNase also did not affect the transforming ability.

Deoxyribonuclease (DNase): Enzyme that degrades DNA. Treatment with DNase abolished the transforming ability, indicating that DNA was essential for transformation.

Transformation Assay: They introduced the treated extracts into cultures of non-virulent (R strain) bacteria.

Transformation into the virulent form occurred only when DNA was intact, confirming DNA's role as the transforming principle.

Results and Interpretation

The critical finding was that only the DNA fraction retained the ability to transform the non-virulent bacteria. When DNA was degraded, transformation ceased. This led Avery and his colleagues to conclude that “a nucleic acid of the deoxyribose type is the fundamental unit of the transforming principle.”

Their language was cautious — the idea that DNA was the genetic material was so revolutionary that even they stopped short of asserting it as fact. But the implication was clear.

Scientific Impact: Slow Acceptance and Ultimate Validation

Despite the elegance of their experimental design and the reproducibility of their results, the wider scientific community was initially reluctant to accept DNA as the genetic material. It would take nearly a decade, and the reinforcement of the 1952 Hershey-Chase experiment (which used radiolabeled bacteriophages to confirm DNA's role), before the biological world fully embraced this molecular paradigm shift.

Yet it is now widely acknowledged that the Avery-MacLeod-McCarty experiment was the first conclusive demonstration of DNA’s role in heredity. It set the stage for the discovery of the double helix structure by Watson and Crick in 1953, and ultimately for the development of modern genetics, PCR, gene cloning, and sequencing technologies.

Relevance Today: A Molecular Milestone Still Guiding Innovation

For researchers in the molecular detection field — including those focused on qPCR, nucleic acid extraction, and custom assay development — the legacy of this experiment is not just historical. It validates every decision we make when designing DNA-based detection tools, optimizing primer sequences, and interpreting amplification curves.

The ability to manipulate, quantify, and detect DNA with such confidence is rooted in the foundational work that Avery and his colleagues laid down more than 80 years ago.

The Silent Spread: Understanding Candida auris and Its Resistance Profile

Candida auris (C. auris) is an emerging multidrug-resistant yeast that poses a significant global health threat, particularly within healthcare settings.

First identified in Japan in 2009, this pathogen has rapidly spread across continents, causing outbreaks in hospitals and long-term care facilities. Its ability to resist multiple antifungal treatments, persist on surfaces, and evade standard cleaning protocols has made it a formidable challenge for infection control and public health.

Historical Context and Emergence

The initial isolation of C. auris occurred in 2009 from the ear canal of a patient in Japan.

Subsequent retrospective analyses revealed earlier cases, suggesting that the yeast had been present but misidentified due to limitations in diagnostic methodologies. By 2016, C. auris had been reported in multiple countries, prompting the Centers for Disease Control and Prevention (CDC) to issue a clinical alert to U.S. healthcare facilities.

The pathogen's rapid global dissemination and its propensity to cause healthcare-associated outbreaks underscored the need for heightened surveillance and improved diagnostic capabilities.

Current Epidemiology and Clinical Impact

In recent years, the incidence of C. auris infections has escalated dramatically. According to the CDC, there were 4,514 clinical cases reported in the United States in 2023, marking a significant increase from previous years. States such as California, Florida, and Nevada have reported the highest number of cases, with California alone documenting 1,566 infections in 2023.

C. Auris primarily affects individuals with underlying health conditions, particularly those in intensive care units or requiring invasive medical devices. Infections can manifest as bloodstream infections, wound infections, or ear infections, often leading to severe complications and high mortality rates. Mortality rates associated with C. auris infections range from 30% to 60%, especially among patients with comorbidities.

Antimicrobial Resistance and Treatment Challenges

One of the most alarming characteristics of C. auris is its resistance to multiple classes of antifungal agents. Studies have shown that over 90% of isolates are resistant to fluconazole, approximately 15% to amphotericin B, and a smaller percentage to echinocandins.

The emergence of pan-resistant strains—resistant to all three major classes of antifungals—has been documented, further complicating treatment options.

This resistance profile necessitates the use of combination antifungal therapies and underscores the urgent need for novel antifungal agents.

Recent Outbreaks and Infection Control Concerns

Healthcare facilities have reported numerous outbreaks of C. auris, often involving transmission among patients in intensive care units.

A multiyear outbreak in a burn intensive care unit in Illinois from 2021 to 2023 resulted in 28 cases, despite the implementation of outbreak response and mitigation measures.

C. auris’ ability to persist on surfaces and resist standard disinfectants contributes to its spread within healthcare environments.

Traditional disinfectants may be ineffective against C. auris, necessitating the use of EPA-registered hospital-grade disinfectants with proven efficacy against this pathogen.

Future Directions and Research Initiatives

Addressing the threat posed by C. auris requires a multifaceted approach, including enhanced surveillance, rapid diagnostic testing, effective infection control practices, and the development of new antifungal agents.

Recent research has identified novel antifungal compounds with activity against C. auris, offering hope for more effective treatments. Additionally, genomic studies are providing insights into the mechanisms of resistance and transmission, informing strategies to curb the spread of this pathogen.

Public health agencies and healthcare institutions must remain vigilant, ensuring adherence to infection prevention protocols and investing in research to combat this emerging threat.

In conclusion, Candida auris represents a significant and evolving challenge in the realm of infectious diseases. Its rapid emergence, multidrug resistance, and propensity for causing healthcare-associated outbreaks necessitate immediate and sustained attention from the global health community.

Through concerted efforts in surveillance, research, and infection control, it is possible to mitigate the impact of this formidable pathogen.

At BioPathogenix, we support laboratories working at the forefront of fungal research with tools designed for precision and scalability. Our BPX™ qPlex Candida Reagents offer robust detection of Candida auris alongside other clinically relevant Candida species, streamlining workflows in surveillance and antifungal resistance studies. Built for real-time PCR platforms and validated for multiplex performance, this reagent kit empowers researchers to confidently identify and monitor C. auris with high sensitivity and specificity.

Whether you’re tracking emerging threats or running high-throughput screens, we invite you to explore our range of products to see how our solutions fit into your laboratory's detection and identification strategies.

Celebrating Female Scientists Who Shaped the PCR Revolution

Dr. Susanne Stoffel

While Kary Mullis received the Nobel Prize for inventing PCR, Dr. Susanne Stoffel worked closely on early thermocycling optimization. Though lesser-known, her contributions to enzyme fidelity and reaction conditions were essential in early validation phases — highlighting the many behind-the-scenes women in molecular breakthroughs.

Dr. Jennifer Doudna

A biochemist and CRISPR co-inventor, Dr. Doudna's foundational work in RNA interference and gene editing transformed molecular biology. Her career showcases how core nucleic acid mechanisms like those leveraged in PCR are tied to broader advancements in genetic diagnostics and therapeutics.

Dr. Mary-Claire King

Renowned for discovering the BRCA1 gene and its link to hereditary breast cancer, Dr. King was also a pioneer in using molecular techniques for forensic and anthropological identification. Her work laid the groundwork for PCR-based genetic testing in cancer research.

Dr. Elaine Mardis

Dr. Mardis is a key figure in the development of next-generation sequencing (NGS) and high-throughput PCR applications. Her leadership at the Institute for Genomic Medicine has helped drive precision oncology using molecular diagnostics.

Dr. Anna-Marie Lauzon

As an early adopter of real-time PCR in clinical workflows, Dr. Lauzon worked on qPCR methods for respiratory pathogen detection and quantitative viral load monitoring contributing to the standardization of molecular diagnostics in hospitals.

Dr. Elizabeth Blackburn

Awarded the Nobel Prize for her discovery of telomerase, Dr. Blackburn's work heavily utilized PCR-based amplification and cloning strategies. Her research not only advanced cancer biology but also pushed the limits of long-fragment PCR in genetic aging studies.

Dr. Patricia Doyle

A specialist in molecular virology, Dr. Doyle was one of the earliest public health scientists to advocate for PCR-based detection in bioterrorism response protocols, helping build early pathogen surveillance systems in the 1990s and 2000s.

Dr. Debora Kelley

Instrumental in developing thermostable polymerases, Dr. Kelley contributed to enhancing Taq polymerase variants that increased specificity and yield — helping bring PCR into faster and more sensitive real-world applications.

Dr. Helen Lee

Founder of Diagnostics for the Real World, Dr. Lee pioneered simple, robust PCR-based diagnostics for use in low-resource settings. Her work bridges high science with global accessibility, making her a crucial figure in global health innovation.

Dr. Marilyn Kozak

Best known for the “Kozak consensus sequence” in eukaryotic translation, her studies enabled better gene cloning, expression studies, and mRNA quantification — all of which deeply intersect with modern PCR primer design and assay development.

Carrying Their Legacy Forward

The story of PCR is not just about invention — it’s about refinement, perseverance, and vision. The women highlighted here advanced science in ways that continue to impact global health, pathogen surveillance, and molecular discovery.

At BioPathogenix, we’re proud to build upon that legacy by supporting the next generation of molecular scientists — and by ensuring our tools reflect the rigor, innovation, and inclusivity that these pioneers championed.

Pathogen Risk Radar What to Watch - April 2025

As global connectivity, climate shifts, and antimicrobial resistance continue to shape the public health landscape, laboratories and surveillance teams remain on the front lines of emerging pathogen detection. This month’s Pathogen Risk Radar brings attention to four organisms currently under active monitoring —

New Bat Coronavirus in Brazil

Scientists have identified a novel coronavirus in bats in São Paulo and Ceará, Brazil, exhibiting significant genetic similarities to the Middle East Respiratory Syndrome (MERS) virus, which has a fatality rate of approximately one-third of known patients. The spike protein of this new virus shares a 71.74% similarity with that of MERS, raising concerns about its potential to infect humans. While there is no immediate cause for alarm, ongoing monitoring and research are essential to assess the risks associated with this virus.

Measles Resurgence

The United Kingdom is experiencing a significant rise in vaccine-preventable diseases, including measles. Factors such as declining vaccination rates, increased social interaction, and international travel have contributed to this surge. Health authorities are emphasizing the importance of maintaining high immunization coverage to prevent outbreaks and protect public health.

Candida Auris

Candida auris is an emerging multidrug-resistant yeast that poses a significant threat in healthcare settings. It has been associated with severe infections and high mortality rates, particularly among immunocompromised individuals. The fungus's resistance to multiple antifungal agents and its ability to persist on surfaces make it challenging to control. Healthcare facilities are advised to implement strict infection control measures and conduct regular surveillance to detect and manage outbreaks promptly.

Dengue Virus

Dengue fever, a mosquito-borne viral infection, has seen a significant uptick in cases across the Americas. The Centers for Disease Control and Prevention (CDC) reports over 760,000 cases this year, marking a 15% increase compared to the previous five-year average. Areas such as Puerto Rico and the U.S. Virgin Islands have been particularly affected. With no specific antiviral treatment available, emphasis remains on preventive measures, including mosquito control and public education on reducing exposure.

While the pathogens covered here vary in transmission mode, geography, and clinical impact, they all reflect the urgent need for early detection, sustained public health infrastructure, and adaptive research strategies. At BioPathogenix, we’re committed to supporting researchers, institutions, and public health professionals with the insights and reagent systems needed to stay ahead of the curve. Stay connected for next month’s Pathogen Risk Radar as we continue to track emerging threats and empower scientific response.

Thank You for Reading This Month’s Edition of the BioPathogenix Newsletter.

We’re grateful to share space with so many dedicated researchers, lab professionals, and public health advocates working to stay ahead of emerging threats. Be sure to join us next month as we continue tracking high-impact pathogens, spotlighting molecular breakthroughs, and sharing tools to support your work at the bench and beyond.

To stay connected between issues, follow BioPathogenix on LinkedIn or reach out directly — we’re always here to collaborate, support, and grow with the scientific community.

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