Introduction Carp oedema virus (CEV) is a relatively understudied poxvirus. It exhibits an affinity for gill and skin epithelial cells. Investigations were conducted into selected aspects of CEV biology, with a focus on determining cell and tissue tropism of CEV, acquiring gene sequences and updating CEV tests in fish tissues. Material and Methods A total of 238 common carp tissue samples from nine aquaculture farms were analysed. The study evaluated the efficacy of intermediate detection of CEV by real-time PCR and in situ hybridisation. The genes encoding protein P4a were sequenced, analysed and aligned in a phylogenetic tree using a molecular evolution model. Results In situ hybridisation revealed the necessity to validate the Centre for Environment, Fisheries and Aquaculture Science protocols for sampling for CEV detection and to use the tissues for which the virus has the highest tropism, namely the skin and kidneys, rather than solely the gills. The level of genetic variability was determined, and it was shown that CEV mutates systematically. The creation of two distinct phylogenetic clades confirms certain strains’ description as Polish isolates. Conclusion Determining the localisation of CEV genetic material in organs and tissues is pivotal for shaping the World Organisation for Animal Health guidelines. The utility of molecular diagnostics has been demonstrated in the skin and kidney of carp, in addition to the gills, impelling their inclusion in diagnostic protocols. The clusters identified in the phylogenetic tree offer valuable insights for developing the current PCR primers. The prevalence of CEV infection in aquaculture, juxtaposed with its notably lower detection in wild fish, underscores the significance of mandatory molecular diagnostic testing for CEV in carp farming.

中文翻译：

---

评估鲤鱼水肿病毒分离株的趋向性和遗传特征以增强检测策略

简介 鲤鱼水肿病毒 (CEV) 是一种研究相对较少的痘病毒。它对鳃和皮肤上皮细胞具有亲和力。对 CEV 生物学的选定方面进行了调查，重点是确定 CEV 的细胞和组织向性、获取基因序列并更新鱼类组织中的 CEV 测试。材料和方法 对来自 9 个水产养殖场的总共 238 个鲤鱼组织样本进行了分析。该研究评估了实时荧光定量 PCR 中间检测 CEV 的效果，就地杂交。使用分子进化模型对编码蛋白质 P4a 的基因进行测序、分析和比对，在系统发育树中。结果原位杂交表明有必要验证环境、渔业和水产养殖科学中心的 CEV 检测采样方案，并使用病毒具有最高趋向性的组织，即皮肤和肾脏，而不仅仅是鳃。确定了遗传变异水平，结果表明 CEV 发生系统性突变。两个不同的系统发育分支的创建证实了某些菌株作为波兰分离株的描述。结论 确定 CEV 遗传物质在器官和组织中的定位对于制定世界动物卫生组织指南至关重要。除了鳃之外，分子诊断的实用性已在鲤鱼的皮肤和肾脏中得到证实，这促使它们被纳入诊断方案中。系统发育树中识别的簇为开发当前的 PCR 引物提供了宝贵的见解。水产养殖中 CEV 感染的流行，以及野生鱼类中 CEV 感染率明显较低的情况，强调了对鲤鱼养殖中 CEV 进行强制性分子诊断检测的重要性。