Comparison of mitochondrial genetic variation of Taenia hydatigena cysticerci from China and Mongolia

Abstract

Parasitic infection is one of the many challenges facing livestock production globally. Cysticercosis tenuicollis is a common parasitic disease in domestic and wild ruminants (intermediate host) caused by the larval stage of Taenia hydatigena primarily through infecting dogs (de nitive host). Although there are handful of genetic studies on this parasite, there is no available genetic data for the parasite in Mongolia. So, the main aim of this study was to identify the nuclear differences in ovine isolates of Cysticercus tanuicollis entering China from Mongolia and comparison with existing Chinese isolates from sheep and goats based on the recently described PCR-RFLP method and mitochondrial genes of NADH dehydrogenase subunit 4 (nad4) and the NADH dehydrogenase subunit 5 (nad5). Sixty nine isolates were collected during routine veterinary meat inspections from sheep that originated from Mongolia, at the modern Slaughterhouses in Erenhot City, Inner Mongolia. Additional 114 cysticerci were also retrieved from sheep and goats from northern (Inner Mongolia Autonomous Region, Ningxia Hui Autonomous Region and Gansu Province), western (Tibet Autonomous Region), and southern (Jiangxi Province and Guangxi Province) China. The PCR-RFLP approach of the nad5 showed nine mitochondrial clusters such as A1, A2, A3, A5, A8, A9, A10, A11 and B of T. hydatigena isolates from sheep and goats from Mongolia and China. Meanwhile, RFLP pro le of Haplogroup A1 was extensively spread than other Haplogroups. Therefore, these data provide supplementary information on the molecular epidemiology of T. hydatigena for China and Mongolia as animal movement between both countries is constantly occurring. This study also demonstrates that the genetic variants of T. hydatigena existing in China and Mongolia are closely similar. HighlightsCysticercosis caused by the larval stage of Taenia hydatigena is endemic in China and Mongolia.The pairwise xation index (Fst) showed the absence of genetic differentiation between sheep Cysticercus tenuicollis isolates from China and Mongolia for nad4 and concatenated nad4-nad5 mitochondrial gene sequences. Meanwhile, Fst for nad5 showed the presence of few genetic variation between sheep. However, C. tenuicollis from Chinese sheep were differentiated from goats.Our investigations for nad5 indicated the existence of nine mitochondrial clusters such as A1, A2, A3, A5, A8, A9, A10, A11 and B of T. hydatigena isolates from sheep and goats from China and Mongolia.