The host-associated microbiome is increasingly recognized as a critical player in health and immunity. Recent studies have shown that disruption of commensal microbial communities can contribute to disease pathogenesis and severity. Santa Catalina Island foxes (Urocyon littoralis catalinae) present a compelling system in which to examine microbial dynamics in wildlife due to their depauperate genomic structure and extremely high prevalence of ceruminous gland tumors. Although the precise cause is yet unknown, infection with ear mites (Otodectes cynotis) has been linked to chronic inflammation, which is associated with abnormal cell growth and tumor development. Given the paucity of genomic variation in these foxes, other dimensions of molecular diversity, such as commensal microbes, may be critical to host response and disease pathology. We characterized the host-associated microbiome across six body sites of Santa Catalina Island foxes, and performed differential abundance testing between healthy and mite-infected ear canals. We found that mite infection was significantly associated with reduced microbial diversity and evenness, with the opportunistic pathogen Staphylococcus pseudintermedius dominating the ear canal community. These results suggest that secondary bacterial infection may contribute to the sustained inflammation associated with tumor development. As the emergence of antibiotic resistant strains remains a concern of the medical, veterinary, and conservation communities, uncovering high relative abundance of S. pseudintermedius provides critical insight into the pathogenesis of this complex system. Through use of culture-independent sequencing techniques, this study contributes to the broader effort of applying a more inclusive understanding of molecular diversity to questions within wildlife disease ecology.

中文翻译：

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耳螨感染与遗传退化的圣卡塔利娜岛狐狸（Urocyon littoralis catalinae）中微生物群落的改变有关。

与宿主相关的微生物组被公认为健康和免疫的关键因素。最近的研究表明，共生微生物群落的破坏可导致疾病的发病机理和严重程度。圣卡塔利娜岛狐狸（Urocyon littoralis catalinae）提出了一种引人注目的系统，该系统可检查野生动物的微生物动力学，因为它们的基因组结构更弱，且陶瓷腺瘤的患病率极高。尽管确切的原因尚不清楚，但耳螨（耳语）的感染与慢性炎症有关，慢性炎症与细胞的异常生长和肿瘤的发展有关。鉴于这些狐狸的基因组变异很少，因此分子多样性的其他方面（例如共生微生物）对于宿主反应和疾病病理可能至关重要。我们表征了圣卡塔利娜岛狐狸六个身体部位的宿主相关微生物组，并进行了健康和螨虫感染的耳道之间的差异丰度测试。我们发现螨虫感染与减少微生物多样性和均匀度显着相关，机会病原体葡萄球菌假单胞菌占主导地位。这些结果表明，继发性细菌感染可能导致与肿瘤发展相关的持续炎症。由于抗生素抗性菌株的出现仍然是医学界，兽医界和保护界关注的一个问题，揭露假丝酵母的相对高丰度为这一复杂系统的发病机理提供了重要的见识。通过使用与文化无关的测序技术，