From wastewater to wound care: How phages are found, harvested, and used

Imagine the intricate journey of bacteriophages, starting from their origins in wastewater to their crucial role in wound care.

This fascinating process of finding, harvesting, and utilising these microscopic viruses is a testament to the precision and ingenuity of modern science. But what makes phages so extraordinary in fighting infections, and how do researchers unlock their medical potential?

The answers lie in the careful steps involved in discovering, refining, and applying these powerful agents, offering a promising glimpse into the future of infection treatment.

What are bacteriophages?

Bacteriophages, or phages, are viruses that specifically target and infect bacteria. These remarkable entities have a protein coat that encases their genetic material, which they inject into bacterial cells.

Once inside, phages hijack the bacterial machinery to replicate themselves, ultimately causing the bacteria to burst and releasing new phages to infect neighboring cells.

Phages come in a variety of shapes and sizes, from simple structures to intricate forms. Some have tails that enable them to latch onto specific bacterial receptors, while others feature complex mechanisms for injecting their genetic material into their host.

Their specificity in targeting bacteria makes phages a compelling alternative to antibiotics, especially as antibiotic resistance continues to rise.

By unraveling the mechanisms by which phages infect bacteria, scientists can harness their potential to combat bacterial infections with unprecedented precision.

Where are phages found?

Phages are ubiquitous, thriving in diverse environments ranging from soil and water to the human body. They are instrumental in controlling bacterial populations and maintaining ecological balance.

• Soil: In terrestrial environments, phages help regulate bacterial communities, playing a vital role in ecosystem health.
• Water sources: Rivers, lakes, and other freshwater bodies harbour diverse phage populations that interact with aquatic bacteria.
• Oceans: Marine environments are teeming with phages, with an estimated 10³⁰ individual phages worldwide, making them one of the most abundant biological entities on Earth.
• The human microbiome: Within our bodies, phages are integral to the microbiome, influencing bacterial composition and activity.
• Sewage: Sewage systems are rich in bacteria and phages, making wastewater a treasure trove for harvesting phages with therapeutic potential.

Why sewage is a goldmine for

Sewage represents an ideal environment for finding bacteriophages due to its high concentration of bacterial hosts and microbial diversity.

Here’s why:

1. Abundant bacterial hosts: Human waste provides a fertile ground for bacteria, creating an ideal environment for phages to thrive.
2. High phage diversity: The varied microbial ecosystem in sewage fosters a wide spectrum of phages, increasing the chances of finding those suited to specific bacterial infections.
3. Continuous evolution: Constant bacterial and phage interactions drive the evolution of highly specialised and adaptable phages.
4. Natural selection: The competitive environment ensures that only the most effective phages survive, making them potent candidates for medical use.

How scientists identify therapeutic phages

The journey to identify therapeutic phages begins in the lab, where researchers rigorously evaluate the interactions between phages and bacteria.

Here’s how it works:

• Bacterial screening: Phages are exposed to various bacterial strains to identify those capable of effectively targeting harmful bacteria.
• Genome sequencing: By analysing the genetic makeup of phages, scientists can determine their suitability for combating specific infections.
• Resistance testing: Researchers assess the ability of phages to overcome bacterial defense mechanisms, ensuring their effectiveness against antibiotic-resistant strains.

Harvesting and purifying

Once identified, phages are harvested and purified for therapeutic use through a meticulous process:

1. Sample collection: Researchers collect samples from rich sources like sewage, soil, and water.
2. Enrichment: Samples are treated to concentrate phages, making them easier to isolate.
3. Isolation: Techniques such as filtration and centrifugation separate phages from other materials.
4. Purification: Methods like chromatography refine phages, ensuring they are free from contaminants.
5. Testing: Phages undergo rigorous assessments for safety, potency, and genetic stability.

Testing for safety and efficacy

Before therapeutic use, phages are subjected to thorough testing to ensure they are safe and effective:

1. In vitro testing: Laboratory studies confirm their ability to target harmful bacteria without affecting human cells.
2. In vivo testing: Animal models are used to evaluate real-world efficacy and safety.
3. Toxicity screening: Phages are examined for harmful toxins or adverse immune responses.
4. Genetic stability: Researchers confirm that the phages’ genetic material remains consistent across replications, ensuring reliable performance.

Matching phages to specific infections

Precision is key in phage therapy. Scientists carefully analyse the genetic makeup of both the phage and the target bacteria to ensure a perfect match.

DNA sequencing of the phage and its host bacteria helps identify phages capable of destroying harmful bacteria while sparing beneficial microbes. This targeted approach minimises disruption to the body’s microbiome, enhancing treatment outcomes.

Real-life applications of phage therapy

Phage therapy is revolutionising infection treatment with its targeted precision and versatility:

• Combating antibiotic resistance: Phages provide an effective alternative for treating drug-resistant infections.
• Minimising side effects: Unlike broad-spectrum antibiotics, phages target only harmful bacteria, preserving beneficial microbes.
• Treating chronic infections: Persistent infections unresponsive to traditional therapies can be addressed using phages.
• Personalised medicine: Phage therapy allows for tailored treatment plans, optimising outcomes for individual patients.

The journey of phages, from their discovery in wastewater to their use in wound care and beyond, showcases the incredible potential of these microscopic allies.

As antibiotic resistance continues to rise, phage therapy offers a promising path forward, combining scientific ingenuity with the power of nature to combat even the most formidable bacterial infections.