The EmsB Tandemly Repeated Multilocus Microsatellite: a New Tool To Investigate Genetic Diversity of Echinococcus granulosus Sensu Lato

Abstract

Cystic echinococcosis (CE) is a widespread and severe zoonotic disease caused by infection with the larval stage of the eucestode Echinococcus granulosus sensu lato. The polymorphism exhibited by nuclear and mitochondrial markers conventionally used for the genotyping of different parasite species and strains does not reach the level necessary for the identification of genetic variants linked to restricted geographical areas. EmsB is a tandemly repeated multilocus microsatellite that proved its usefulness for the study of genetic polymorphisms within the species E. multilocularis, the causative agent of alveolar echinococcosis. In the present study, EmsB was used to characterize E. granulosus sensu lato samples collected from different host species (sheep, cattle, dromedaries, dogs, and human patients) originating from six different countries (Algeria, Mauritania, Romania, Serbia, Brazil, and the People's Republic of China). The conventional mitochondrial cox1 and nad1 markers identified genotypes G1, G3, G5, G6, and G7, which are clustered into three groups corresponding to the species E. granulosus sensu stricto, E. ortleppi, and E. canadensis. With the same samples, EmsB provided a higher degree of genetic discrimination and identified variations that correlated with the relatively small-scale geographic origins of the samples. In addition, one of the Brazilian single hydatid cysts presented a hybrid genotypic profile that suggested genetic exchanges between E. granulosus sensu stricto and E. ortleppi. In summary, the EmsB microsatellite exhibits an interesting potential for the elaboration of a detailed map of the distribution of genetic variants and therefore for the determination and tracking of the source of CE.

Genetic survey of alveolar and cystic echinococcoses in Romania: first molecular evidence of Echinococcus multilocularis in humans in the country

“…This indicated a substantial role of livestock trade, which has facilitated the parasite dispersal over vast areas, in shaping phylogeographical G1 pattern. In connection with a single human sample identifi ed here as E. granulosus G3, a relatively high proportion of the G3 genotype (28.2 %, 46 of 163 isolates) in the samples typed as E. granulosus s.s. was before detected in Romania when markers with the G1-G3 resolution power were used (Bart et al, 2006;Badaraco et al, 2008;Maillard et al, 2009;Casulli et al, 2012;Mitrea et al, 2014;Šnábel et al, 2016). This genetic form was found in sheep, cattle and pig in the country, whereas the present fi nding provides the fi rst report of G3 in humans from Romania.…”

Global Distribution of Alveolar and Cystic Echinococcosis

“…CE was very rarely diagnosed before the World War II, but numbers increased later on, and in 1997 the incidence was estimated to be 0.21 per 10 5 inhabitants (Bobic et al, 2012). So far, E. granulosus (G1) has been reported in humans, sheep and swine, and E. intermedius (G7) in humans and swine (Colovic, 2009;Maillard et al, 2009) (Table 8). Interestingly, infections in swine were of major significance in the past (Dakkak, 2010); however, recently infections in sheep might be of higher relevance (Bobic et al, 2012).…”

High genetic differentiation of Aegla longirostri (Crustacea, Decapoda, Anomura) populations in southern Brazil revealed by multi-loci microsatellite analysis

“…Counteracting this, the chosen molecular marker proved to be very sensitive, since high levels of genetic polymorphism was assessed with reproducibility in A. longirostri genome. Some studies were successfully carried out with this kind of molecular marker, using a heteroduplex assay or using automated genetic analysis for genotyping (Bart et al, 2006;Maillard et al, 2009;Knapp et al, 2010).…”