Reinventing the fight against bacteria, one phage at a time.

Phage Therapy: Understanding the Patient Journey Through a Personalized Treatment Antibiotic resistance poses a significant challenge to modern medicine, leading to the resurgence of interest in alternative therapies such as bacteriophage therapy, or phage therapy. This approach utilizes viruses that specifically infect and kill bacteria, offering hope where traditional antibiotics fail. However, for many patients and practitioners alike, the pathway from diagnosis to treatment remains abstract and complex. By examining a typical patient’s journey through phage therapy, it becomes possible to demystify the process and highlight the personalized nature of this innovative treatment. Consider the case of Sarah, a 42-year-old woman from Boston, Massachusetts. After undergoing surgery to repair a chronic wound on her leg, Sarah developed an infection resistant to multiple antibiotics. Her infectious disease specialist recommended exploring phage therapy, which required travel to a special...

Where Do Bacteriophages Come From?  A Scientific Exploration of Their Natural Origins and Discovery Bacteriophages, or simply phages, are viruses that infect and kill bacteria. Far from being rare or exotic, they are among the most abundant and diverse biological entities on Earth. Despite their microscopic size, their influence spans from the oceanic depths to the human microbiome. Understanding where phages originate and how they are discovered reveals not only their ecological importance but also their potential as therapeutic tools in the age of antibiotic resistance. Bacteriophages exist wherever bacteria thrive. This means they are present in virtually every ecosystem: soil, freshwater, marine environments, sewage, and the intestines of animals, including humans. In fact, it is estimated that there are around 10³¹ phages on the planet—ten million trillion trillion—making them more numerous than all other organisms combined (Hatfull, 2008). These viral particles are constant...

How a Bacteriophage Attacks a Bacterium: The Invisible War Beneath the Microscope In the vast and unseen world of microbes, one of the most fascinating biological battles takes place between bacteriophages—viruses that infect bacteria—and their microbial hosts. Though invisible to the naked eye, this interaction has captivated scientists for over a century and is now at the forefront of biomedical innovation, particularly in the fight against antibiotic resistance. But how exactly does a bacteriophage (or "phage") attack a bacterium? This article breaks down the infection cycle in accessible terms, while preserving the scientific depth of what is, in essence, a microscopic act of precision warfare. A Precise Predator Bacteriophages are highly specialized viruses that infect only bacteria. They do not infect humans, animals, or plants, which makes them uniquely safe and attractive as therapeutic agents. Despite their simplicity—they lack metabolism and cannot reproduce on...

What If Antibiotics Stopped Working? Understanding Antibiotic Resistance and the Revival of Bacteriophage Therapy In the golden age of antibiotics, few could imagine a world where bacterial infections were again life-threatening. But today, that future is no longer hypothetical. Antibiotic resistance is accelerating at a pace that alarms global health experts, creating what many have termed a “silent pandemic.” The World Health Organization has declared antimicrobial resistance (AMR) one of the top 10 global public health threats facing humanity. In this context, a century-old biological weapon— bacteriophages —is being re-evaluated not just as an alternative, but as a necessity. Artistic view The Scale of the Problem Antibiotics, introduced widely in the 1940s, have saved hundreds of millions of lives. Yet overuse, misuse, and agricultural dependence have led to the rise of resistant bacteria. Today: 1.27 million people died globally in 2019 as a direct result of antibiotic-res...

Understanding Bacteriophage Life Cycles: The Lytic and Lysogenic Pathways Bacteriophages, or phages for short, are viruses that infect and replicate within bacteria. They are the most abundant biological entities on Earth, with an estimated 10³¹ particles—more than all the stars in the universe. But despite their microscopic size, phages have a massive influence on microbial ecosystems, human health, and the future of medicine. At the core of how phages function are two distinct reproductive strategies: the lytic cycle and the lysogenic cycle . Understanding these two pathways is essential for grasping how phage therapy works, how bacterial populations are controlled in nature, and how genetic material can be transferred between microorganisms. The Lytic Cycle: Destruction for Reproduction In the lytic cycle, a phage takes over a bacterium with the sole purpose of producing as many new phage particles as possible. The process is swift and lethal to the host cell. Stages of the ly...

The Viruses That Kill Bacteria: An Introduction to Bacteriophages When people hear the word "virus," they often think of disease, danger, and global pandemics. But not all viruses are harmful to humans. In fact, some viruses exclusively target bacteria—and they may hold the key to solving one of the greatest medical challenges of our time: antibiotic resistance. These viruses are called bacteriophages. What Are Bacteriophages? Bacteriophages, or simply phages, are viruses that infect and destroy bacteria. The term comes from the Greek words "bacteria" and "phagein," meaning "to devour." True to their name, phages invade bacterial cells, hijack their machinery to reproduce, and eventually destroy them from within. Discovered over a century ago, phages are the most abundant biological entities on the planet. It is estimated that there are more than 10³¹ phages on Earth—far more than all other organisms combined. They are found wherever bacteria...

Bacteriophages: Ancient Predators and the Next Frontier in Medicine In the animated documentary The Deadliest Being on Planet Earth , the Kurzgesagt team delves into the world of bacteriophages—viruses that prey exclusively on bacteria. With vibrant visuals and precise narration, the video introduces viewers to an invisible ecosystem where microscopic hunters orchestrate life-and-death dramas that shape the biosphere. These entities, though virtually unknown to the general public, may soon become central to the future of medicine. At the heart of the video lies a paradox: bacteriophages (or "phages") are among the most abundant biological entities on Earth—outnumbering all other organisms combined—yet their therapeutic potential has been largely sidelined in the antibiotic era. The video outlines the historical trajectory of phage research, spotlighting Félix d’Hérelle’s early 20th-century work and the rise of phage therapy, only to show how it was later eclipsed by the dis...