Abstract Aphanomyces invadans, an oomycyte fungus most frequently recognized as a causative agent of epizootic ulcerative syndrome (EUS) is a seasonal epidemic pathogen of great importance in wild and farmed fish in both freshwater and estuarine environments. EUS is a complex infectious etiology which leads to necrosis ulcerative lesions and granulomatous response in fishes. It is a cause of death of approximately 92 species that has been recorded in wild as well as in commercial culture systems worldwide. Several environmental and biological factors are responsible for the growth and establishment of A. invadans, which further attracts secondary pathogens to enter the lesions thus, increasing the severity of the infection. Methods for the proper identification of A. invadans, includes PCR detection and microscopy. However, the pathogenicity of the A. invadans is still unknown. In order to discover new effective treatment to fight the disease, a better understanding of the infection process is necessary. The studies on fungal infection in fishes indicate the immune response pattern in fish against A. invadans that serves as an important key for the development of targeted therapeutics and vaccines to prevent the disease and to maintain EUS free aquaculture systems. The immune mechanisms that respond to stimulation, interaction between the immune system of host species and A. invadans, different factors of A. invadans and its pathogenicity as well as various approaches of treatment has been discussed in this review.

中文翻译：

---

引起真菌入侵的流行性溃疡综合征 (EUS) 的致病性和病理生物学及其在鱼类中的免疫反应

摘要 Aphanomyces invadans 是一种最常被认为是流行性溃疡综合征 (EUS) 病原体的卵细胞真菌，是一种季节性流行病病原体，在淡水和河口环境中的野生和养殖鱼类中具有重要意义。EUS 是一种复杂的传染性病因，可导致鱼类坏死性溃疡性病变和肉芽肿反应。它是全世界野生和商业养殖系统中记录的大约 92 种物种的死亡原因。几种环境和生物因素是入侵 A. 的生长和建立的原因，这进一步吸引了次生病原体进入病灶，从而增加了感染的严重程度。正确识别 A. invadans 的方法包括 PCR 检测和显微镜检查。然而，A. invadans 的致病性仍然未知。为了发现新的有效治疗方法来对抗这种疾病，有必要更好地了解感染过程。对鱼类真菌感染的研究表明，鱼类对 A. invadans 的免疫反应模式是开发靶向疗法和疫苗以预防疾病和维持无 EUS 水产养殖系统的重要关键。本综述讨论了对刺激作出反应的免疫机制、宿主物种的免疫系统与入侵者之间的相互作用、入侵者的不同因素及其致病性以及各种治疗方法。有必要更好地了解感染过程。对鱼类真菌感染的研究表明，鱼类对 A. invadans 的免疫反应模式是开发靶向疗法和疫苗以预防疾病和维持无 EUS 水产养殖系统的重要关键。本综述讨论了对刺激作出反应的免疫机制、宿主物种的免疫系统与入侵者之间的相互作用、入侵者的不同因素及其致病性以及各种治疗方法。有必要更好地了解感染过程。对鱼类真菌感染的研究表明，鱼类对 A. invadans 的免疫反应模式是开发靶向疗法和疫苗以预防疾病和维持无 EUS 水产养殖系统的重要关键。本综述讨论了对刺激作出反应的免疫机制、宿主物种的免疫系统与入侵者之间的相互作用、入侵者的不同因素及其致病性以及各种治疗方法。