Development of EST-derived microsatellite markers to investigate the population structure of sparganum — the causative agent of zoonotic sparganosis

Abstract

The plerocercoid (sparganum) of Spirometra erinaceieuropaei is the main aetiological agent of human sparganosis. To improve the current knowledge on S. erinaceieuropaei evolution, we performed multi-locus microsatellite typing of sparganum isolates from China for the first time. All available expressed sequence tag (EST) sequences for the Spirometra were downloaded from the GenBank. The identification and localization of microsatellites in ESTs was accomplished by MISA. Based on the selected microsatellites, the genetic structure of 64 sparganum isolates collected from 11 geographical locations in southwest China were investigated through principal component analysis, STRUCTURE analysis and neighbour-joining clustering. A total of 522 non-redundant ESTs containing 915 simple sequence repeats were identified from 12 481 ESTs screened. Five primer pairs were finally selected. Using these loci, a total of 12 alleles were detected in 64 sparganum isolates. Little variability was observed within each of geographical population, especially among isolates derived from Kunming of Yunnan (YN-KM) province. Both STRUCTURE analysis and the clustering analysis supported that two genotypes existed among the sparganum isolates from southwest China. In conclusion, five microsatellite markers were successfully developed, and sparganum population was observed to harbour low genetic variation, further investigation with deeper sampling was needed to elucidate the population structure.

Large-scale survey of a neglected agent of sparganosis Spirometra erinaceieuropaei (Cestoda: Diphyllobothriidae) in wild frogs in China

“…One surprising finding was that no infected frogs were found in Northeast China (Heilongjiang, Jilin and Liaoning) over the 6 year study period, although 7955F + Sd-8567R). Lanes 2,4,6,8,10,12,14,16,18,20,22,24,26,and 28 indicate amplification with S. erinaceieuropaei-specific primers (Se/Sd-1800F + Se-2018R and Se/Sd-7955F + Se-8356R). Lanes 1-12, samples from Anhui Province; Lanes 13-22, samples from Yunnan Province; Lanes 23-28, samples from Fujian Province.…”

“…The actual number of infections may be far higher than those estimated because many cases may not be recognized or reported. As a result, the investigation of infection by plerocercoid larva (sparganum) in frogs is therefore valuable for food safety and the prevention and control of human sparganosis in China [10].…”

Molecular characteristics of glutathione transferase gene family in a neglect medical Spirometra tapeworm

“…The plerocercoid of Spirometra tapeworms were isolated from wild frogs ( Pelophylax nigromaculatus ) using method described before ( 22 ). The collected worms were tentatively identified as S. mansoni by molecular typing based on the mitochondrial cytochrome c oxidase subunit 1 ( cox 1) gene according to the method detailed in Kuchta et al ( 3 ).…”

Genetic structure of Spirometra mansoni (Cestoda: Diphyllobothriidae) populations in China revealed by a Target SSR-seq method

“…SSRs, also known as microsatellites, are highly variable repetitive elements with nucleotide motifs of 1–6 bp and are ubiquitous in most eukaryotic organisms [ 17 ]. SSRs have been verified as suitable markers for inferring genetic variance and population differences in cestode species [ 14 , 18 – 22 ]. However, traditional analysis based on gel electrophoresis cannot distinguish base differences or changes correctly in SSR amplicons, often causing false positive or false negative results in SSR detection [ 23 ].…”