Costa Antonella, Graci Stefania, Cammilleri Gaetano, Buscemi Maria Drussilla, Collura Rosaria, Vella Antonio, Ferrantelli Vincenzo
Istituto Zooprofilattico Sperimentale della Sicilia, Via Gino Marinuzzi 3, 90129 Palermo, Italy.
J Parasitol. 2018 Aug;104(4):398-406. doi: 10.1645/16-60. Epub 2018 May 16.
Samples obtained from 11 teleost fish species collected in waters off of the Mediterranean coasts of Sicily, Italy, were examined for the presence of Hysterothylacium spp. larvae. In total, 3,017 fish samples were examined, and the larvae recovered were used in subsequent phylogenetic studies. Fifty-eight raphidascaridid parasitic nematodes were found in the examined fish, with prevalence values ranging from 0.2% in anchovies to 60% in forkbeard samples. Twenty-seven parasites were identified as Hysterothylacium fabri and Hysterothylacium aduncum by sequencing the following regions: the nuclear ribosomal internal transcribed spacer ( ITS) and the mitochondrial cytochrome c oxidase subunit II ( COXII). Two other larvae collected from Lophius piscatorius had very low identity scores, with ITS and COXII sequences reported in GenBank and high genetic distances (AY603539). Pairwise comparisons between the ITS region of the H. fabri isolated from fishes from Sicilian coastal waters and those isolated from the Mediterranean Sea, Turkey (KC852206), revealed genetic differences ranging from 0.015 to 0.018. Our H. aduncum samples had very low genetic differences to H. aduncum from the Adriatic Sea (KP979763, 0.00-0.003). The concatenated phylogenetic examination of the ITS- COXII sequences by using maximum likelihood analyses indicated 3 distinct clades supported by high bootstrap values. Further molecular identification and detailed morphological analyses are needed to clarify these results and confirm the diversity and relationships within Hysterothylacium.
对从意大利西西里岛地中海沿岸水域采集的11种硬骨鱼样本进行检查,以确定是否存在后圆线虫属幼虫。总共检查了3017个鱼类样本,回收的幼虫用于后续的系统发育研究。在所检查的鱼类中发现了58条针蛔科寄生线虫,流行率值范围从凤尾鱼中的0.2%到叉牙鱼样本中的60%。通过对以下区域进行测序,将27条寄生虫鉴定为法氏后圆线虫和钩状后圆线虫:核糖体核糖核酸内转录间隔区(ITS)和线粒体细胞色素c氧化酶亚基II(COXII)。从长鳍红娘鱼采集的另外两条幼虫与GenBank中报告的ITS和COXII序列具有非常低的一致性得分和高遗传距离(AY603539)。对从西西里沿海水域鱼类中分离出的法氏后圆线虫的ITS区域与从地中海、土耳其分离出的那些(KC852206)进行成对比较,发现遗传差异范围为0.015至0.018。我们的钩状后圆线虫样本与来自亚得里亚海的钩状后圆线虫(KP979763,0.00 - 0.003)的遗传差异非常小。通过使用最大似然分析对ITS - COXII序列进行串联系统发育检查,结果表明有3个不同的进化枝,得到了高自展值的支持。需要进一步的分子鉴定和详细的形态学分析来阐明这些结果,并确认后圆线虫属内的多样性和关系。