Killer fungus threatening amphibians: Study

A new aquatic fungus is threatening the existence of many of the amphibians like frogs and toads that have existed for 360 million years, a new study claimed. Bd infects over 350 amphibian species by penetrating their skin, but little else is known about where it came from and how it causes disease.

In this undated file photo provided by International Union for Conservation of Nature, shows a Rabbs Fringe-limbed Treefrog, one of 1,895 amphibian species that could soon disappear in the wild. Photo AP

A new aquatic fungus is threatening the existence of many of the amphibians like frogs and toads that have existed for 360 million years, a new study claimed.

The fungus, Batrachochytrium dendrobatidis (Bd), was found to be associated with waves of amphibian extinctions in Central America and north-eastern Australia in the 1990’s, according to an article in journal Microbiology Today . Bd infects over 350 amphibian species by penetrating their skin, but little else is known about where it came from and how it causes disease.

The earliest published record of Bd is from a specimen of an African clawed frog in 1938 from South Africa. Around this time there was a huge trade in clawed frogs when they were used in one of the earliest human pregnancy tests.

The global exportation of the clawed frog is likely to have spread Bd around the world. The infection is spread by fungal spores released into the water supply from imported infected animals.

Researchers are trying different approaches to treat existing Bd infection. Some are treating tadpoles with antifungal drugs, whilst more innovative approaches involve introducing ‘probiotic’ bacteria that naturally secrete antifungal compounds which kill Bd on amphibians’ skin.

To help limit the spread of infection, the World Organization for Animal Health (WOAH) now recommended screening imported amphibians for presence of Bd.