Abstract：
BACKGROUND: Marek\'s disease (MD) is a lymphoproliferative disease caused by Gallid alphaherpesvirus 2 (GaHV-2, MDV-1), which primarily affects chickens. However, the virus is also able to induce tumors and polyneuritis in turkeys, albeit less frequently than in chickens.
RESULTS: This is the first study in Turkey reporting the molecular characterization of a MDV-1 strain detected in a flock of backyard turkeys exhibiting visceral lymphoma. Here, MEQ, vIL-8, pp38 and 132-bp tandem repeat regions, which are frequently preferred in the pathotyping of MDV-1, were examined. It was determined that the MEQ gene of MDV-1/TR-21/turkey strain obtained in the present study encoded 339 amino acids (1020 nt) and had four proline-rich repeat regions (PPPP). Based on the nucleotide sequence of the MEQ gene of the MDV-1/TR-21/turkey strain, a phylogenetic tree was created using the MEGA-X software with the Maximum Likelihood Method (in 1000 replicates). Our strain was highly identical (> 99.8) to the Italian/Ck/625/16, Polish (Polen5) and some Turkish (Layer-GaHV-2-02-TR-2017, Tr/MDV-1/19) MDV-1 strains. Also, nt and aa sequences of the MEQ gene of our strain were 99.1 and 99.41% identical to another Turkish strain (MDV/Tur/2019) originated from chickens. Sequence analysis of pp38 and vIL-8 genes also supported the above finding. The identity ratios of nucleotide and amino acid sequences of vIL-8 and pp38 genes of MDV-1/TR-21/turkey strain were 99.64-100% and 99.79-100%, respectively, when compared with those of the Polish strain. According to 132-bp tandem repeat PCR results, the MDV-1/TR-21/turkey strain had five copies.
CONCLUSIONS: These results suggested that the MDV-1/TR-21/turkey strain obtained from backyard turkeys can be either very virulent or very virulent plus pathotype, though experimental inoculation is required for precise pathotyping.
RESULTS: This is the first study in Turkey reporting the molecular characterization of a MDV-1 strain detected in a flock of backyard turkeys exhibiting visceral lymphoma. Here, MEQ, vIL-8, pp38 and 132-bp tandem repeat regions, which are frequently preferred in the pathotyping of MDV-1, were examined. It was determined that the MEQ gene of MDV-1/TR-21/turkey strain obtained in the present study encoded 339 amino acids (1020 nt) and had four proline-rich repeat regions (PPPP). Based on the nucleotide sequence of the MEQ gene of the MDV-1/TR-21/turkey strain, a phylogenetic tree was created using the MEGA-X software with the Maximum Likelihood Method (in 1000 replicates). Our strain was highly identical (> 99.8) to the Italian/Ck/625/16, Polish (Polen5) and some Turkish (Layer-GaHV-2-02-TR-2017, Tr/MDV-1/19) MDV-1 strains. Also, nt and aa sequences of the MEQ gene of our strain were 99.1 and 99.41% identical to another Turkish strain (MDV/Tur/2019) originated from chickens. Sequence analysis of pp38 and vIL-8 genes also supported the above finding. The identity ratios of nucleotide and amino acid sequences of vIL-8 and pp38 genes of MDV-1/TR-21/turkey strain were 99.64-100% and 99.79-100%, respectively, when compared with those of the Polish strain. According to 132-bp tandem repeat PCR results, the MDV-1/TR-21/turkey strain had five copies.
CONCLUSIONS: These results suggested that the MDV-1/TR-21/turkey strain obtained from backyard turkeys can be either very virulent or very virulent plus pathotype, though experimental inoculation is required for precise pathotyping.
摘要：
背景：马立克氏病（MD）是由Gallidα疱疹病毒2（GaHV-2，MDV-1）引起的淋巴增生性疾病，主要影响鸡。然而,该病毒还能够在火鸡中诱发肿瘤和多神经炎，尽管频率低于鸡。
结果：这是土耳其的第一项研究，报告了在一群表现出内脏淋巴瘤的后院火鸡中检测到的MDV-1菌株的分子特征。这里,MEQ,vIL-8，pp38和132-bp串联重复区，检查了在MDV-1的致病分型中经常首选的方法。确定在本研究中获得的MDV-1/TR-21/火鸡株的MEQ基因编码339个氨基酸（1020nt），并具有四个富含脯氨酸的重复区（PPPP）。根据MDV-1/TR-21/火鸡株MEQ基因的核苷酸序列，使用具有最大似然法的MEGA-X软件创建系统发育树(重复1000次)。我们的菌株与意大利/Ck/625/16，波兰（Polen5）和一些土耳其（Layer-GaHV-2-02-TR-2017，Tr/MDV-1/19）MDV-1菌株高度相同（>99.8）。此外，我们菌株的MEQ基因的nt和aa序列与源自鸡的另一种土耳其菌株（MDV/Tur/2019）具有99.1和99.41％的同一性。pp38和vIL-8基因的序列分析也支持上述发现。MDV-1/TR-21/火鸡株的vIL-8和pp38基因的核苷酸和氨基酸序列的同一性分别为99.64-100%和99.79-100%,分别,与波兰菌株相比。根据132-bp的串联重复PCR结果，MDV-1/TR-21/火鸡株有5个拷贝.
结论：这些结果表明，从后院火鸡获得的MDV-1/TR-21/火鸡菌株可以是非常强的或非常强的加上致病型，尽管需要实验接种才能进行精确的病理分型。
结果：这是土耳其的第一项研究，报告了在一群表现出内脏淋巴瘤的后院火鸡中检测到的MDV-1菌株的分子特征。这里,MEQ,vIL-8，pp38和132-bp串联重复区，检查了在MDV-1的致病分型中经常首选的方法。确定在本研究中获得的MDV-1/TR-21/火鸡株的MEQ基因编码339个氨基酸（1020nt），并具有四个富含脯氨酸的重复区（PPPP）。根据MDV-1/TR-21/火鸡株MEQ基因的核苷酸序列，使用具有最大似然法的MEGA-X软件创建系统发育树(重复1000次)。我们的菌株与意大利/Ck/625/16，波兰（Polen5）和一些土耳其（Layer-GaHV-2-02-TR-2017，Tr/MDV-1/19）MDV-1菌株高度相同（>99.8）。此外，我们菌株的MEQ基因的nt和aa序列与源自鸡的另一种土耳其菌株（MDV/Tur/2019）具有99.1和99.41％的同一性。pp38和vIL-8基因的序列分析也支持上述发现。MDV-1/TR-21/火鸡株的vIL-8和pp38基因的核苷酸和氨基酸序列的同一性分别为99.64-100%和99.79-100%,分别,与波兰菌株相比。根据132-bp的串联重复PCR结果，MDV-1/TR-21/火鸡株有5个拷贝.
结论：这些结果表明，从后院火鸡获得的MDV-1/TR-21/火鸡菌株可以是非常强的或非常强的加上致病型，尽管需要实验接种才能进行精确的病理分型。
