Nannizziopsis屬黴菌感染臺灣野外入侵種蜥蜴及圈養蜥蜴之調查

Abstract

Nannizziopsis屬黴菌是一種重要的蜥蜴病原，過去曾被歸類為Chrysosporium anamorph of Nannizziopsis vriesii (CANV)複合體。蜥蜴被感染後常見的症狀為出現皮膚的病灶，並且可能會死於二次性感染。Nannizziopsis屬黴菌不只可以感染寵物蜥蜴，也能感染野生動物，因此可能會有生態上的危害。在台灣，寵物綠鬣蜥曾經有Nannizziopsis屬黴菌感染的紀錄，由於綠鬣蜥在台灣是分布廣泛的強勢外來種，我們擔心牠可能會將此疾病傳播至原生種身上。在這個研究中，我們希望能了解Nannizziopsis屬黴菌是否存在於這些外來蜥蜴物種，同時也納入寵物蜥蜴的調查，希望能找出野外蜥蜴和寵物蜥蜴身上的Nannizziopsis屬黴菌是否有關聯性。本研究使用的野外蜥蜴包括綠鬣蜥(Iguana iguana)、綠水龍(Physignathus cocincinus)、和沙氏變色蜥(Anolis sagrei)，我們將牠們的來源依照捕捉地點分為固定樣區及非固定樣區。牠們的皮膚病灶會以無菌操作進行採樣，樣本會進行黴菌培養、分子鑑定、以及病理檢驗。我們發現Nannizziopsis屬黴菌在固定樣區的綠鬣蜥整體有0.98%的盛行率，這些綠鬣蜥感染的都是N. dermatitidis這個物種；而綠水龍及沙氏變色蜥身上則沒有發現Nannizziopsis屬黴菌的感染。至於寵物蜥蜴的部分，N. guarroi是最常感染寵物蜥蜴的Nannizziopsis屬黴菌，另外我們也發現了一例N. dermatitidis感染珠寶蜥(Timon Lepidus)的案例及一例Nannizziopsis屬新種感染尼日王者蜥(Uromastyx Geyri)的案例。在這個研究中我們證實了Nannizziopsis屬黴菌確實存在於野外環境，然而這些黴菌可能不是如我們所想的藉由外來種傳入，而是本來就存在於台灣的自然環境中。未來建議對原生蜥蜴進行調查以了解這個疾病實際的影響。

Nannizziopsis spp., belonging to Chrysosporium anamorph of Nannizziopsis vriesii (CANV) complex in the past, are recognized as a significant fungal pathogen for lizards. Infected lizards typically present with skin lesions and may die of a secondary infection. Nannizziopsis spp. infect not only pet lizards but also wildlife, thus raising a conservation concern. In Taiwan, Nannizzopsis infections have been reported in captive green iguanas. We were concerned that green iguanas, as an invasive lizard distributed widely, would spread this disease to native species. We conducted a survey aimed at detecting Nannizziopsis infection in wild invasive lizards. Captive lizards were also included to discover the relationship between Nannizziopsis spp. in the wild and captive lizards. The wild lizards, including green iguanas (Iguana iguana), Chinese water dragons (Physignathus cocincinus), and brown anoles (Anolis sagrei), were categorized into two groups, namely the permanent sites and the non-permanent sites, based on their origin. The skin lesions were aseptically biopsied, and the samples were subjected to fungal culture, molecular analysis, and histopathological examination. We found an overall prevalence of 0.98% for wild green iguanas in the permanent sites, all of which were infected by N. dermatitidis. Nannizziopsis infection was not detected in the populations of Chinese water dragons and brown anoles. For captive lizards, N. guarroi was the most frequently isolated pathogen in skin lesions, while N. dermatitidis and a noval Nannizziopsis sp. were also isolated from an ocellated lizard (Timon Lepidus) and a Geyr’s spiny-tailed lizard (Uromastyx Geyri), respectively. We confirmed the presence of Nannizziopsis spp. in the wild in this study; however, the fungus may be native to Taiwan but not introduced by alien species as the initial hypothesis suggested. Close monitoring and surveillance of native lizard populations is warranted to realize the influence of this disease.