Department of Veterinary Pathology and Public Health, Hassan 2nd Institute of Agronomy and Veterinary Medicine, B.P. 6202, Rabat, Morocco.
Department of Veterinary Pathology and Public Health, Hassan 2nd Institute of Agronomy and Veterinary Medicine, B.P. 6202, Rabat, Morocco,
Avian Dis. 2024 Sep;68(3):217-224. doi: 10.1637/aviandiseases-D-24-00004.
Gizzard erosion and ulceration syndrome (GEUS) is caused by a fowl adenovirus serotype 1 (FAdV-1) and was first reported in laying hens in Japan in 1993. This syndrome has emerged as an epizootic in Morocco since 2014, causing significant economic losses for the poultry industry, but no involvement of a FAdV has been confirmed. Thus, the objective of this work was to assess GEUS cases that occurred in the country and to determine the role of FAdVs in their occurrence. Investigations were based on a retrospective reassessment of tissue sections and paraffin blocks of gizzards and livers from GEUS cases between 2014 and 2021 coupled with a prospective search of cases in 2022. Gizzards and livers were fixed in 10% neutral buffered formalin for histopathologic examinations according to standard methods and stored at -20 C for molecular analysis. After deparaffinizing, 10-µm-thick tissue sections along with fresh organs were subjected to DNA extraction using a commercial kit. A primer pair specific for the Hexon gene of FAdVs was used in conventional PCR; in contrast, for real-time PCR, a primer pair targeting the 52K gene was employed. In total, 24 flock cases with characteristic GEUS were assessed between 2014 and 2022. They were nine broiler cases aged between 11 and 39 days, 11 layer cases with an age between 17 and 29 wk, two cases in meat-type breeders aged 10 and 27 wk, and two flock cases of turkey poults aged 22 and 23 days. In most cases, microscopic lesions were consistent with an ulcerative and lymphoplasmocytic ventriculitis, and pathognomonic viral intranuclear inclusion bodies within degenerate epithelial cells were identified in four broiler flock cases, four layer cases, and one case in breeders and hence were highly suggestive of a FAdV infection. Among these nine cases that were positive at the histopathologic examination, six cases were found to be FAdV-PCR positive; another four cases were negative to histology but FAdV-PCR positive. Furthermore, a sequencing analysis was conducted, providing the initial evidence of the implication of FAdV-1 from species A as the cause of GEUS in Moroccan poultry. Additionally, a phylogenetic analysis was executed to facilitate a comparison between the strains investigated in this study and those identified in diverse geographic regions and across various time periods.
肌胃糜烂溃疡综合征（GEUS）由禽腺病毒血清型 1（FAdV-1）引起，于 1993 年在日本产蛋母鸡中首次报道。自 2014 年以来，这种综合征在摩洛哥爆发，给家禽业造成了重大经济损失，但尚未证实与 FAdV 有关。因此，本研究的目的是评估该国发生的 GEUS 病例，并确定 FAdV 在其发生中的作用。调查基于对 2014 年至 2021 年间发生的 GEUS 病例的组织切片和石蜡块进行回顾性重新评估，并结合 2022 年对病例的前瞻性搜索。按照标准方法，将肌胃和肝脏固定在 10%中性缓冲福尔马林中，用于组织病理学检查，并在-20°C 下储存，以备分子分析。脱蜡后，用商业试剂盒从 10-µm 厚的组织切片和新鲜器官中提取 DNA。使用针对 FAdV 六邻体基因的引物对进行常规 PCR；相比之下，使用针对 52K 基因的引物对进行实时 PCR。总共评估了 2014 年至 2022 年间 24 个具有典型 GEUS 的禽群病例。它们包括 9 个 11-39 日龄的肉鸡病例、11 个 17-29 周龄的蛋鸡病例、2 个 10-27 周龄的肉种鸡病例和 2 个 22-23 日龄火鸡雏鸡病例。在大多数情况下，显微镜下的病变与溃疡性和淋巴浆细胞性心包炎一致，在 4 个肉鸡群病例、4 个蛋鸡病例和 1 个种鸡病例中发现了退化上皮细胞内具有特征性的病毒核内包涵体，高度提示 FAdV 感染。在组织病理学检查阳性的这 9 个病例中，有 6 个病例的 FAdV-PCR 检测结果为阳性；另有 4 个病例组织学检查为阴性，但 FAdV-PCR 检测结果为阳性。此外，还进行了测序分析，为 FAdV-1 种 A 作为引起摩洛哥家禽 GEUS 的原因提供了初步证据。此外，进行了系统发育分析，以方便比较本研究中调查的菌株与在不同地理区域和不同时间段确定的菌株。
