PDF(Pubmed)
Abstract：
BACKGROUND: members of the genus Sarcocystis are intracellular obligate protozoan parasites classified within the phylum Apicomplexa and have an obligate heteroxenous life cycle involving two hosts. A more comprehensive understanding of the prevalence and geographic range of different Sarcocystis species in marine ecosystems is needed globally and nationally. Hence, the objective of this study was to document the incidence of Sarcocystis infection in sharks within the aquarium ecosystem of Egypt and to identify the species through the characterization of the SSU rDNA gene.
METHODS: All organs of the mako shark specimen underwent macroscopic screening to detect the existence of a Sarcocystis cyst. Ten cysts were collected from the intestine and processed separately to extract the genomic DNA. The polymerase chain reaction (PCR) was accomplished by amplifying a specific 18S ribosomal RNA (rRNA) gene fragment. Subsequently, the resulting amplicons were subjected to purification and sequencing processes.
RESULTS: Macroscopic examination of the mako shark intestinal wall sample revealed the presence of Sarcocystis cysts of various sizes and shapes, and sequencing of the amplicons from Sarcocystis DNA revealed a 100% nucleotide identity with the sequence of Sarcocystis tenella recorded from sheep in Iran; The mako shark sequence has been deposited in the GeneBank with the accession number OQ721979. This study presents the first scientific evidence demonstrating the presence of the Sarcocystis parasite in sharks, thereby documenting this specific marine species as a novel intermediate host in the Sarcocystis life cycle.
CONCLUSIONS: This is the first identification of Sarcocystis infection in sharks, and we anticipate it will be an essential study for future screenings and establishing effective management measures for this disease in aquatic ecosystems.
METHODS: All organs of the mako shark specimen underwent macroscopic screening to detect the existence of a Sarcocystis cyst. Ten cysts were collected from the intestine and processed separately to extract the genomic DNA. The polymerase chain reaction (PCR) was accomplished by amplifying a specific 18S ribosomal RNA (rRNA) gene fragment. Subsequently, the resulting amplicons were subjected to purification and sequencing processes.
RESULTS: Macroscopic examination of the mako shark intestinal wall sample revealed the presence of Sarcocystis cysts of various sizes and shapes, and sequencing of the amplicons from Sarcocystis DNA revealed a 100% nucleotide identity with the sequence of Sarcocystis tenella recorded from sheep in Iran; The mako shark sequence has been deposited in the GeneBank with the accession number OQ721979. This study presents the first scientific evidence demonstrating the presence of the Sarcocystis parasite in sharks, thereby documenting this specific marine species as a novel intermediate host in the Sarcocystis life cycle.
CONCLUSIONS: This is the first identification of Sarcocystis infection in sharks, and we anticipate it will be an essential study for future screenings and establishing effective management measures for this disease in aquatic ecosystems.
摘要：
背景：肉孢子虫属的成员是细胞内专性原生动物寄生虫，分类在Apicomplex门内，并具有涉及两个宿主的专性异氧生命周期。需要在全球和国家范围内更全面地了解海洋生态系统中不同肉孢子虫物种的患病率和地理范围。因此，这项研究的目的是记录埃及水族馆生态系统中鲨鱼的肉囊虫感染的发生率，并通过SSUrDNA基因的表征来鉴定该物种。
方法：对Mako鲨标本的所有器官进行宏观筛查，以检测结囊囊肿的存在。从肠收集十个囊肿并分别处理以提取基因组DNA。通过扩增特定的18S核糖体RNA（rRNA）基因片段来完成聚合酶链反应（PCR）。随后，对得到的扩增子进行纯化和测序过程。
结果：对mako鲨肠壁样本的宏观检查显示存在各种大小和形状的肉囊虫囊肿，和对SarcocystisDNA的扩增子进行测序显示，与伊朗绵羊记录的Sarcocystistenella序列具有100％的核苷酸同一性；Mako鲨鱼序列已存放在GeneBank中，登录号为OQ721979。这项研究提出了第一个科学证据，证明鲨鱼中存在肉孢子虫寄生虫，从而记录了这种特定的海洋物种作为Sarcocystis生命周期中的新型中间宿主。
结论：这是鲨鱼中结节虫感染的首次鉴定，我们预计这将是未来在水生生态系统中对这种疾病进行筛查和建立有效管理措施的重要研究。
方法：对Mako鲨标本的所有器官进行宏观筛查，以检测结囊囊肿的存在。从肠收集十个囊肿并分别处理以提取基因组DNA。通过扩增特定的18S核糖体RNA（rRNA）基因片段来完成聚合酶链反应（PCR）。随后，对得到的扩增子进行纯化和测序过程。
结果：对mako鲨肠壁样本的宏观检查显示存在各种大小和形状的肉囊虫囊肿，和对SarcocystisDNA的扩增子进行测序显示，与伊朗绵羊记录的Sarcocystistenella序列具有100％的核苷酸同一性；Mako鲨鱼序列已存放在GeneBank中，登录号为OQ721979。这项研究提出了第一个科学证据，证明鲨鱼中存在肉孢子虫寄生虫，从而记录了这种特定的海洋物种作为Sarcocystis生命周期中的新型中间宿主。
结论：这是鲨鱼中结节虫感染的首次鉴定，我们预计这将是未来在水生生态系统中对这种疾病进行筛查和建立有效管理措施的重要研究。
