Department of Pathobiology, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Department of Microbiology, Faculty of Sciences, Islamic Azad University, Karaj, Iran.
Parasitol Res. 2024 Sep 30;123(10):335. doi: 10.1007/s00436-024-08346-3.
Trichomonas gallinae is a widespread protozoan parasite that primarily affects birds, causing a disease known as avian trichomonosis. The present study aimed to investigate the prevalence and genetic diversity of T. gallinae, a parasite causing avian trichomoniasis in feral pigeons, budgerigars, and finches in Tehran, Iran. The 5.8S ribosomal RNA locus, along with the internal transcribed spacer 2 (ITS2) region, has been extensively utilized for genotype identification and for determining inter- and intra-specific diversity. More recently, the Fe-hydrogenase (Fe-Hyd) gene has been suggested as an additional genetic marker to enhance the accuracy of strain subtyping discrimination. In the present study, a total of 12% (12/100) birds examined were infected with T. gallinae using microscopy and PCR methods. Infection was found in seven of 30 (23.3%) feral pigeons, three of 40 (7.5%) budgerigars, and two of 30 (6.66%) finches. Analysis of the ITS2 region of T. gallinae isolates revealed two highly similar sequences. The first sequence (GenBank: OQ689964-OQ689970) was found in five feral pigeons and two budgerigars, whereas the second sequence (GenBank: OQ689971-OQ689975) was identified in two feral pigeons, one budgerigar, and two finches. Phylogenetic analysis confirmed the presence of two distinct clusters (cluster I and cluster II) within the trichomonads based on the ITS2 region. However, further analysis using Fe-Hyd revealed greater diversity, with three subtypes identified (A1, A2, and C1). One isolate identified in the present study (GenBank accession number: OQ694508.1) belonged to subtype A1. Combining ITS2 and Fe-Hyd markers holds promise for a more comprehensive understanding of the population structure of T. gallinae and the potential role of ITS2 in host adaptation.
鸡滴虫是一种广泛分布的原生动物寄生虫，主要感染鸟类，导致禽类滴虫病。本研究旨在调查伊朗德黑兰的野生鸽子、虎皮鹦鹉和雀科鸟中引起禽类滴虫病的寄生虫鸡滴虫的流行率和遗传多样性。5.8S 核糖体 RNA 基因座以及内部转录间隔区 2（ITS2）区域已被广泛用于基因型鉴定和种内及种间多样性的确定。最近，铁氢化酶（Fe-Hyd）基因被提议作为额外的遗传标记，以提高菌株亚型区分的准确性。在本研究中，通过显微镜和 PCR 方法检查了 100 只鸟，发现有 12%（12/100）感染了鸡滴虫。在 30 只野生鸽子中，有 7 只（23.3%）、40 只虎皮鹦鹉中有 3 只（7.5%）和 30 只雀科鸟中有 2 只（6.66%）感染了鸡滴虫。对鸡滴虫分离株的 ITS2 区域分析显示出两个高度相似的序列。第一个序列（GenBank：OQ689964-OQ689970）在 5 只野生鸽子和 2 只虎皮鹦鹉中发现，第二个序列（GenBank：OQ689971-OQ689975）在 2 只野生鸽子、1 只虎皮鹦鹉和 2 只雀科鸟中发现。系统发育分析证实，基于 ITS2 区域，在滴虫中有两个不同的簇（簇 I 和簇 II）。然而，进一步使用 Fe-Hyd 分析显示出更高的多样性，共鉴定出 3 个亚型（A1、A2 和 C1）。本研究鉴定出的一个分离株（GenBank 登录号：OQ694508.1）属于 A1 亚型。结合 ITS2 和 Fe-Hyd 标记有望更全面地了解鸡滴虫的种群结构以及 ITS2 在宿主适应中的潜在作用。
