A deadly fungus, Batrachochytrium dendrobatidis, is causing devastation among frog and toad populations worldwide. This fungus, known as Bd or the amphibian chytrid fungus, infects and destroys amphibians’ skin, leading to heart failure and eventual death due to electrolyte loss. The pandemic caused by Bd has contributed to or caused the possible extinction of 90 amphibian species and the severe decline of over 500 others.
Researchers at the University of California, Riverside, have discovered a virus that infects Bd and believe it can be genetically engineered to control or eradicate the fungal disease, potentially saving declining amphibian populations. This discovery is promising for conserving amphibians, which play vital roles in ecosystems by controlling insect populations, serving as indicators of habitat and water quality, and providing environmental signals in response to climate change.
The global decline and extinction of amphibian populations have been a concern since the 1970s and 1980s, with the discovery of the Bd fungus in 1999 shedding light on the primary threat to amphibian biodiversity. The researchers’ excitement at finding the Bd-infecting virus stemmed from their desire to study how different fungal strains vary globally and how the virus could potentially alter the fungus’ pathogenicity. The virus’s presence in only some fungal strains makes it challenging to study and understand its effects on amphibian populations.
The researchers plan to clone the virus to investigate its influence on fungal attributes and amphibian susceptibility. Understanding the molecular mechanisms by which the virus alters fungal pathogenicity is crucial for engineering solutions to make the fungus less deadly to amphibians. Furthermore, studying the virus may offer insights into combating other infectious diseases threatening wildlife, such as white-nose fungus in bats.
Susceptibility to Bd varies among amphibian species, with some showing resilience or resistance to the fungus. For example, tadpoles of the mountain yellow-legged frog tend to experience mild effects, while certain invasive species like the marine toad, American bullfrog, and African clawed frog exhibit resistance. These Bd-resistant species could provide valuable insights for protecting more vulnerable amphibians and potentially identifying protective microbial species within the amphibian skin microbiome.
The discovery of the virus infecting Bd opens up new avenues for research into combating the global amphibian pandemic. By understanding the virus’s impact on fungal pathogenicity and amphibian susceptibility, researchers hope to develop strategies for saving declining amphibian populations and preserving biodiversity. Lessons learned from this study may also have broader implications for addressing infectious disease pandemics in other wildlife populations.
