Do bats owe their survival to their cutaneous microbiota?

The cutaneous microbiota in bats affected by white-nose syndrome may be able to adapt itself to help them survive this fungal infection.

Bats play an essential role in the ecosystem; they are natural regulators for the insect population. If they were to disappear, it would have serious health consequences for humans. White-nose syndrome is a potentially fatal infection that affects bats. This zoonosis takes its name from the white ring that forms around their muzzle. Affected animals can no longer control their body temperature: during hibernation periods, they exhaust their reserves and die of starvation. Others die from opportunistic infections. Caused by the fungus Pseudogynoascus destructans, white-nose syndrome is believed to have caused millions of bat deaths since its detection in the United States in 2006, seriously threatening the survival of chiroptera.

Certain species, however, have managed to survive. Looking more closely at the microbial composition of their skin, survivors had a drop in the intensity of the infection. In fact their microbiota permanently included Pseudogynoascus destructans without it causing the disease. This suggests that the cutaneous microflora has adapted to resist the fungus. As the microbial ecosystem of the skin is heavily influenced by the environment, a Canadian team compared the microbiota of sick and healthy bats while simultaneously taking samples from their habitat during hibernation. The results show that the cutaneous microbiota of bats that survived in areas infected by Pseudogynoascus destructans was rich in antifungal bacteria, which allowed them, if not to resist, then at least to tolerate the fungus. Changing bats’ cutaneous microbiota may thus help to fight this devastating zoonosis. However, the authors caution against the risks associated with such an approach. It is important to target the pathogen without causing any collateral damage to the microbial ecosystem of either the bat or its hibernation shelter.  

Lemieux-Labonté et al. Enrichment of beneficial bacteria in the skin microbiota of bats persisting with white-nose syndrome. Microbiome (2017) 5:115