In the 100th episode of Matters Microbial, host Dr. Mark Martin is joined by Dr. Heather Hendrickson of the University of Canterbury, New Zealand, to discuss her research group's work on using bacteriophage therapy to combat American Foulbrood, a devastating bacterial disease affecting honeybees. Caused by the spore-forming bacterium Paenibacillus larvae, the disease melts larvae from the inside out, and the current control method in New Zealand is to burn the entire infected hive. Dr. Hendrickson's team is developing a sustainable alternative using phage "cocktails"—mixtures of viruses that specifically target and kill the pathogenic bacteria—to prevent infections. The research involves a large-scale, community-driven "phage hunt" with beekeepers, rational design of phage combinations to overcome bacterial resistance, and careful genomic analysis to ensure safety. A key challenge discovered was the presence of a honeybee toxin in some of the most effective phages, which now needs to be engineered out. The project, supported by significant government funding, aims to conduct field trials and develop practical delivery methods in close collaboration with beekeepers and the indigenous Māori community.
Phage Therapy: A New Hope for Protecting Honeybees
2:40Introducing the Topic: Dr. Heather Hendrickson joins the podcast to discuss using bacteriophages (viruses that infect bacteria) to protect honeybees from a deadly bacterial disease, offering a non-human-centered application of phage therapy.
8:35The Problem: American Foulbrood: The focus is on a disease called American Foulbrood, caused by the bacterium Paenibacillus larvae, which is a global threat to honeybees.
9:40Disease Mechanism and Impact: The pathogen infects and "melts" honeybee larvae, producing billions of highly resilient and transmissible spores. In New Zealand, the law requires that any hive showing signs of infection must be completely destroyed by burning.
17:03A Sustainable Solution: Dr. Hendrickson's lab is developing a prophylactic phage therapy treatment. This involves using bacteriophages to protect hives from infection, which would be a sustainable alternative to using antibiotics (which leads to resistance) or burning hives.
18:24Preventing Resistance with Phage Cocktails: The strategy to combat the evolution of phage-resistant bacteria is to use a "cocktail" containing multiple different phages that attack the pathogen through different biological mechanisms, making it extremely difficult for the bacteria to develop resistance to all of them simultaneously.
21:36A Community-Driven "Phage Hunt": To find the necessary phages, the lab initiated a community science project, engaging beekeepers across New Zealand who sent in over 400 soil and bee debris samples. This collaboration was essential for finding the rare phages capable of infecting Paenibacillus larvae.
26:30Rational Cocktail Design: After isolating a collection of phages with names like "Lilo," "Dash," and "Justinda" (named after the former prime minister), the team began testing their effectiveness against different strains of the pathogen to design the most potent and broad-acting cocktail.
33:17A Major Safety Challenge: A critical discovery was made during genomic analysis: some of their most effective phages carried genes for a honeybee toxin. This means the team must now find a way to remove or disable the toxin before the phages can be safely used in hives.
35:32Major Funding for Future Research: The project has secured approximately $9 million NZD in government funding for a 5-year program called "Adaptable Phage Solutions." This will allow for safety testing, field trials, and scaling up production. The program also extends to developing phage therapies for other agricultural sectors, such as salmon aquaculture.
43:54Developing Practical Delivery Methods: The team is exploring user-friendly and inexpensive ways for beekeepers to apply the phage treatment, such as incorporating it into sugar packets, creating a mist, or developing a charged dust that sticks to bees as they enter the hive.
55:24Collaborating with Stakeholders: The project emphasizes the importance of open science communication and stakeholder engagement, working closely with the beekeeping industry and the indigenous Māori community to ensure the technology is developed and deployed in a transparent and culturally respectful manner.