Faculty of Veterinary Medicine, College of Agriculture, Can Tho University, Can Tho, Vietnam.
Can Tho Sub-Department of Animal Health, Ministry of Agriculture and Rural Development, Can Tho, Vietnam.
Open Vet J. 2023 Jun;13(6):690-696. doi: 10.5455/OVJ.2023.v13.i6.3. Epub 2023 Jun 4.
Chicken infectious anemia (CIA) caused by the CIA virus (CIAV) is considered one of the most important immunosuppressive diseases affecting chickens and recently poses a great economic burden to the poultry industry worldwide.
This study aims to identify the presence of CIAV in the Mekong Delta (MD), Vietnam, and to determine genotypes of CIAVs that are currently circulating in this area.
Organ samples (spleen, liver, and thymus) of 144 chickens suspected with CIA from 47 poultry farms were collected. A total of 47 pooled samples, each containing 2-4 chickens from each farm, were tested for the presence of CIAV.
Twenty out of 47 pooled organ samples (pool of 2-4 chickens per farm) were positive for CIAV using polymerase chain reaction targeting the viral VP1 gene. The VP1 amplicons of eight representative CIAVs were subjected to sequencing and genetic characterization. Phylogenetic analysis based on partial VP1 gene sequence revealed that the CIAVs detected in the MD grouped into different genotypes of II, IIIa, and IIIc together with CIAVs previously detected in the northern Vietnam and other Asian countries. The phylogenetic analysis also confirmed that detected CIAVs genetically differed from vaccine strains. In addition, deduced amino acids of the VP1 identified several critical amino acid substitutions in the VP1 protein that are likely associated with the virulence of CIAV.
This is the first report to detect and determine the genetic characterization of the circulating CIAVs in the MD. Therefore, this study provides an important understanding of the evolution of CIAVs and highlights the importance of implementing prompt control measures against CIAVs in the MD and Vietnam.
由鸡传染性贫血病毒（CIAV）引起的鸡传染性贫血（CIA）被认为是影响鸡的最重要的免疫抑制性疾病之一，最近给全球家禽业造成了巨大的经济负担。
本研究旨在确定越南湄公河三角洲（MD）是否存在 CIAV，并确定该地区目前流行的 CIAV 基因型。
采集了来自 47 个家禽养殖场的 144 只疑似 CIA 鸡的器官样本（脾脏、肝脏和胸腺）。总共检测了 47 个混合样本，每个样本包含来自每个农场的 2-4 只鸡，以检测 CIAV 的存在。
使用针对病毒 VP1 基因的聚合酶链反应，从 47 个混合器官样本（每个农场 2-4 只鸡的混合样本）中检测到 20 个 CIAV 阳性。对 8 个具有代表性的 CIAV 的 VP1 扩增子进行测序和遗传特征分析。基于部分 VP1 基因序列的系统发育分析表明，在 MD 检测到的 CIAV 分为不同的基因型 II、IIIa 和 IIIc，与之前在越南北部和其他亚洲国家检测到的 CIAV 一起。系统发育分析还证实，检测到的 CIAV 在遗传上与疫苗株不同。此外，VP1 的推导氨基酸在 VP1 蛋白中鉴定出几个关键的氨基酸替换，这些替换可能与 CIAV 的毒力有关。
这是首次报道在 MD 检测到并确定循环 CIAV 的遗传特征。因此，本研究为了解 CIAV 的进化提供了重要认识，并强调了在 MD 和越南实施针对 CIAV 的及时控制措施的重要性。
