Pathology and Clinical Pathology Department, Faculty of Veterinary Medicine, New Valley University, Kharga, Egypt.
Virology Department, Faculty of Veterinary Medicine, New Valley University, Kharga, Egypt.
Virol J. 2024 Apr 10;21(1):83. doi: 10.1186/s12985-024-02329-7.
Avian leukosis virus Subgroup-J (ALV-J) is a rapidly oncogenic evolving retrovirus infecting a variety of avian species; causing severe economic losses to the local poultry industry.
To investigate ALV-J, a total of 117 blood samples and 57 tissue specimens of different organs were collected for virological, and pathological identification, serological examinations, molecular characterization, and sequencing analysis. To the best of our knowledge, this is the first detailed report recorded in broiler flocks in Egypt. The present study targets the prevalence of a viral tumor disease circulating in broiler flocks in the El-Sharqia, El-Dakahliya, and Al-Qalyubiyya Egyptian governorates from 2021 to 2023 using different diagnostic techniques besides ALV-J gp85 genetic diversity determination.
We first isolated ALV-J on chicken embryo rough cell culture; showing aggregation, rounding, and degeneration. Concerning egg inoculation, embryonic death, stunting, and curling were observed. Only 79 serum samples were positive for ALV-J (67.52%) based on the ELISA test. Histopathological investigation showed tumors consist of uniform masses, usually well-differentiated myelocytes, lymphoid cells, or both in the liver, spleen, and kidneys. Immunohistochemical examination showed that the myelocytomatosis-positive signals were in the spleen, liver, and kidney. The PCR assay of ALV-J gp85 confirmed 545 base pairs with only 43 positive samples (75.4%). Two positive samples were sequenced and submitted to the Genbank with accession numbers (OR509852-OR509853). Phylogenetic analysis based on the gp85 gene showed that the ALV-J Dakahlia-2 isolate is genetically related to ALV-EGY/YA 2021.3, ALV-EGY/YA 2021.4, ALV-EGY/YA 2021.14, and ALV-EGY/YA 2021.9 with amino acid identity percentage 96%, 97%; 96%, 96%; respectively. Furthermore, ALV-J Sharqia-1 isolate is highly genetically correlated to ALV-EGY/YA 2021.14, and ALV-EGY/YA 2021.9, ALV-J isolate QL1, ALV-J isolate QL4, ALV-J isolate QL3, ALV-EGY/YA 2021.4 with amino acid identity percentage 97%, 97%; 98%, 97%, 97%, 95%; respectively.
This study confirmed that ALV-J infection had still been prevalent in broilers in Egypt, and the genetic characteristics of the isolates are diverse.
禽白血病病毒 J 亚群（ALV-J）是一种快速致癌的反转录病毒，感染多种禽类，给当地家禽业造成严重的经济损失。
为了研究 ALV-J，共采集了 117 份血液样本和 57 份不同器官的组织样本，进行病毒学和病理学鉴定、血清学检查、分子特征分析和测序分析。据我们所知，这是在埃及肉鸡群中首次详细记录的病毒性肿瘤疾病。本研究针对 2021 年至 2023 年在埃及的 El-Sharqia、El-Dakahliya 和 Al-Qalyubiyya 省肉鸡群中循环的病毒肿瘤疾病的流行情况，使用不同的诊断技术，除了 ALV-J gp85 遗传多样性测定外。
我们首次在鸡胚粗糙细胞培养物上分离出 ALV-J，表现出聚集、圆化和退化。关于卵接种，观察到胚胎死亡、发育迟缓、卷曲。仅基于 ELISA 试验，有 79 份血清样本呈 ALV-J（67.52%）阳性。组织病理学检查显示，肿瘤由均匀的肿块组成，肝脏、脾脏和肾脏中通常是分化良好的髓细胞、淋巴细胞或两者兼有。免疫组织化学检查显示，髓细胞瘤阳性信号存在于脾脏、肝脏和肾脏中。ALV-J gp85 的 PCR 检测证实有 545 个碱基对，只有 43 个样本（75.4%）为阳性。对两个阳性样本进行测序，并将序列提交给 Genbank，注册号为（OR509852-OR509853）。基于 gp85 基因的系统发育分析表明，达赫拉 2 号 ALV-J 分离株在遗传上与 ALV-EGY/YA 2021.3、ALV-EGY/YA 2021.4、ALV-EGY/YA 2021.14 和 ALV-EGY/YA 2021.9 有关，氨基酸同一性百分比为 96%、97%；96%、96%；分别。此外，沙尔基亚 1 号 ALV-J 分离株与 ALV-EGY/YA 2021.14、ALV-EGY/YA 2021.9、ALV-J 分离株 QL1、ALV-J 分离株 QL4、ALV-J 分离株 QL3、ALV-EGY/YA 2021.4 的遗传关系密切，氨基酸同一性百分比为 97%、97%；98%、97%、97%、95%；分别。
本研究证实，ALV-J 感染在埃及肉鸡中仍很普遍，分离株的遗传特征多样。
