국내･국외 양서류에서 항아리곰팡이(Batrachochytrium dendrobatidis) 감염률과 생존율 분석

Abstract

Rapid population declines in amphibians have been documented worldwide, with Batrachochytrium dendrobatidis(Bd), a fungal pathogen, a dominant cause of such collapses worldwide. In this study, we conducted controlled infection experiments with native anurans(Pelophylax nigromaculatus, Glandirana rugosa) and caudates(Hynobius leechii, H. unisacculus), as well as with non-native spe- cies(tomato frog, Dyscophus guineti, and tiger salamander, Ambystoma mavortium) to evaluate suscept- ibility between species to Bd infection. Infection, survival, corticosterone, and innate immune func- tion(in terms of bacterial killing activity, BKA) were evaluated to evaluate pathogen impact in terms of taxa. The results revealed that fatality and infection in non-native anuran such as tomato frog, were higher compared to native amphibians, with concomitant high-level concentrations of cortico- sterone in infected animals. In contrast, native anuran and caudate species have low infection rates and high survival, with no significant variation between infected and control groups in both BKA and corticosterone levels in both scenarios. All these observations suggest that Asian amphibians, having co-evolved with a long duration with the East Asian-origin Bd lineage, possibly developed partial resistance and quick immune response capabilities. Despite the apparent tolerance in native fauna, Bd introductions via international trade and pet amphibian trading present a continued threat, with pathogen strain development and carrier hosts facilitating secondary dissemination. Quarantine and future management will need to address Bd transmission via introduced species, and further inves- tigation of microbiota in the skin and adaptive immunity will be necessary to enable effective overall mitigation approaches.