Strong restructuration of skin microbiota during captivity challenges ex-situ conservation of amphibians

• Published in: Frontiers in microbiology 2023-02, Vol.14, p.1111018-1111018
• Main Authors: Fieschi-Méric, Léa, Van Leeuwen, Pauline, Hopkins, Kevin, Bournonville, Marie, Denoël, Mathieu, Lesbarrères, David
• Format: Article
• Language: English
• Subjects: amphibian conservation; Aquatic sciences & oceanology; bacterial symbionts; Batrachochytrium dendrobatidis; Environmental sciences & ecology; ex-situ conservation; holobiont conservation; husbrandry practices; Ichtyhosaura alpestris; Life sciences; Lissotriton helveticus; Microbiology; microbiome; microbiota flexibility; Médecine vétérinaire & santé animale; newts; overwintering; population translocation; Sciences aquatiques & océanologie; Sciences de l’environnement & écologie; Sciences du vivant; seasonal habitat-shifts; skin microbiota; survival assurance population; Veterinary medicine & animal health
• ISSN: 1664-302X; 1664-302X
• DOI: 10.3389/fmicb.2023.1111018

In response to the current worldwide amphibian extinction crisis, conservation instances have encouraged the establishment of collections for endangered species. The resulting assurance populations are managed under strict biosecure protocols, often involving artificial cycles of temperature and humidity to induce active and overwintering phases, which likely affect the bacterial symbionts living on the amphibian skin. However, the skin microbiota is an important first line of defense against pathogens that can cause amphibian declines, such as the chytrid . Determining whether current husbandry practices for assurance populations might deplete amphibians from their symbionts is therefore essential to conservation success. Here, we characterize the effect of the transitions from the wild to captivity, and between aquatic and overwintering phases, on the skin microbiota of two newt species. While our results confirm differential selectivity of skin microbiota between species, they underscore that captivity and phase-shifts similarly affect their community structure. More specifically, the translocation is associated with rapid impoverishment, decrease in alpha diversity and strong species turnover of bacterial communities. Shifts between active and overwintering phases also cause changes in the diversity and composition of the microbiota, and on the prevalence of -inhibitory phylotypes. Altogether, our results suggest that current husbandry practices strongly restructure the amphibian skin microbiota. Although it remains to be determined whether these changes are reversible or have deleterious effects on their hosts, we discuss methods to limit microbial diversity loss and emphasize the importance of integrating bacterial communities to applied amphibian conservation.