Parasitology Research Laboratory (PRL), Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, 73170, Thailand.
Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand.
Sci Rep. 2021 Aug 17;11(1):16686. doi: 10.1038/s41598-021-96241-7.
Leucocytozoon sabrazesi is the intracellular protozoa of leucocytozoonosis, which is transmitted by the insect vectors and affects chickens in most subtropical and tropical regions of the globe, except South America, and causing enormous economic losses due to decreasing meat yield and egg production. In this study, L. sabrazesi gametocytes have been observed in the blood smears, and molecular methods have been used to analyse the occurrence and genetic diversity of L. sabrazesi in blood samples from 313 chickens raised in northern, western and southern parts of Thailand. The nested polymerase chain reaction (nested PCR) assay based on the cytb gene revealed that 80.51% (252/313) chickens were positive of L. sabrazesi. The phylogenetic analysis indicated that L. sabrazesi cytb gene is conserved in Thailand, showed 2 clades and 2 subclades with similarity ranged from 89.5 to 100%. The diversity analysis showed 13 and 18 haplotypes of the sequences from Thailand and from other countries, respectively. The entropy analyses of nucleic acid sequences showed 26 high entropy peaks with values ranging from 0.24493 to 1.21056, while those of amino acid sequences exhibited 5 high entropy peaks with values ranging from 0.39267 to 0.97012. The results; therefore, indicate a high molecular occurrence of L. sabrazesi in chicken blood samples with the associated factors that is statistically significant (p < 0.05). Hence, our results could be used to improve the immunodiagnostic methods and to find appropriate preventive control strategies or vaccination programs against leucocytozoonosis in order to mitigate or eliminate the harmful impact of this infection on chicken industry.
沙氏住白细胞虫是白细胞虫病的细胞内原生动物，通过昆虫媒介传播，影响全球大多数亚热带和热带地区的鸡，但不包括南美洲，由于减少了肉产量和蛋产量，造成了巨大的经济损失。在这项研究中，观察到血液涂片中有沙氏住白细胞虫配子体，并使用分子方法分析了来自泰国北部、西部和南部的 313 只鸡血液样本中沙氏住白细胞虫的发生和遗传多样性。基于 cytb 基因的巢式聚合酶链反应（nested PCR）检测显示，80.51%（252/313）的鸡为沙氏住白细胞虫阳性。系统发育分析表明，泰国的沙氏住白细胞虫 cytb 基因保守，显示出 2 个分支和 2 个子分支，相似度为 89.5%至 100%。序列多样性分析显示，来自泰国和其他国家的序列分别有 13 个和 18 个单倍型。核酸序列的熵分析显示有 26 个高熵峰，值范围为 0.24493 至 1.21056，而氨基酸序列的熵分析显示有 5 个高熵峰，值范围为 0.39267 至 0.97012。结果表明，鸡血液样本中沙氏住白细胞虫的分子发生频率很高，与统计上显著相关的因素（p < 0.05）。因此，我们的结果可用于改进免疫诊断方法，并找到针对白细胞虫病的适当预防控制策略或疫苗接种方案，以减轻或消除这种感染对养鸡业的有害影响。
