Otago Researchers Develop Phage Therapy to Combat Bacterial Diseases

Researchers at the University of Otago are advancing the development of phage therapy as a potential solution to combat bacterial diseases affecting agriculture and human health. Led by Prof Peter Fineran and Dr Robert Fagerlund, this project focuses on harnessing bacteriophages, which are viruses that specifically target and kill bacteria. Their efforts aim to address significant challenges faced by New Zealand’s cherry orchards, particularly in controlling the damaging effects of Pseudomonas bacteria.

The project has received funding from the Ministry of Business, Innovation and Employment (MBIE), facilitating research that seeks to create effective phage treatments. Prof Fineran noted that interactions with various orchards in Otago have allowed the team to collect phage samples essential for their studies. The presence of Pseudomonas bacteria can lead to crop losses of between 20% and 50% in young cherry orchards, prompting growers to rely on copper sprays. However, these sprays have proven ineffective over time, as the bacteria develop resistance and the application harms beneficial microbes.

To overcome these challenges, the research team is developing phage cocktails—a combination of different phages, each equipped with unique mechanisms to penetrate bacterial defenses. Prof Fineran explained, “If one phage is blocked, another still gets through. In that way, you end up with a very robust treatment which avoids the emergence of resistance.” This targeted approach contrasts sharply with traditional antibiotics, which can indiscriminately affect beneficial bacteria, leading to broader ecological disruptions.

Innovations in Phage Therapy

The researchers have made significant strides in understanding phage behavior, discovering “jumbo phages” that create protective protein shells within bacteria. This compartment allows phages to replicate while remaining untouched by bacterial enzymes. Additionally, they have identified phages that can shield their DNA with sugars, providing resistance against CRISPR gene-editing technology, which is often employed by bacteria to defend themselves.

Prof Fineran emphasized the importance of these findings, stating, “These types of phages would be good to have in treatments because they were naturally resistant to bacterial countermeasures.” The ongoing trials of phages in hospitals across the West are a testament to their potential, especially in cases where conventional treatments have failed.

While phage therapy is gaining traction in agriculture and medicine, Prof Fineran cautioned that it is not a “silver bullet.” Rather than completely replacing antibiotics and other treatment methods, phages are expected to complement existing therapies. “To be able to choose the right phages to get the desired outcomes, we must understand the bacterial immune systems and learn about all the ways that phages overcome these,” he remarked, highlighting the need for foundational research in this area.

The implications of this research extend beyond orchards, as the principles of phage therapy can also be applied to combat human and animal pathogens. The team’s work not only aims to improve agricultural practices but also holds promise for addressing persistent bacterial infections in clinical settings.

As the project progresses, it represents a significant step in exploring alternative treatments for bacterial diseases, potentially transforming how such infections are managed in both agriculture and healthcare.