Genetic characterization of schistosome species from cattle in Côte d’Ivoire

Abstract

Background Schistosomiasis is a water-based parasitic disease that affects humans, livestock and wild animals. While considerable resources are dedicated to the surveillance, disease mapping, control and elimination of human schistosomiasis, this is not the case for livestock schistosomiasis. Indeed, there are important data and knowledge gaps concerning the species present, population genetic diversity, infection prevalence, morbidity and economic impact. This study aimed to identify circulating schistosome species in cattle across Côte d’Ivoire and to investigate their population diversity and structuring. Methods Overall, 400 adult schistosomes were collected from slaughtered cattle at six sites across Côte d’Ivoire. Additionally, 114 miracidia were collected from live cattle at one site: Ferkessédougou, in the northern part of Côte d’Ivoire. DNA from all specimens was extracted and the cox1 and ITS1/2 regions amplified and analysed to confirm species. The genetic diversity and structuring of the schistosome populations were investigated using 12 microsatellite markers. Results All adult schistosomes and miracidia presented Schistosoma bovis mitochondrial cox1 profile. Nuclear ITS1/2 data were obtained from 101 adult schistosomes and four miracidia, all of which presented an S. bovis profile. Genetic diversity indices revealed a deficiency of heterozygotes and signals of inbreeding across all sites, while structure analyses displayed little geographic structuring and differentiation. Cattle in Côte d’Ivoire thus appear to be mono-species infected with S. bovis. Hybrids of Schistosoma haematobium × S. bovis have not been identified in this study. Cattle schistosomes appear to be panmictic across the country. Conclusions Our results contribute to a deeper understanding of schistosome populations in Ivorian cattle and emphasize a One Health approach of joint human and animal surveillance and prevention and control programmes for schistosomiasis. Graphical Abstract

Population genetic structure ofSchistosoma bovisandS. curassonicollected from cattle in Mali

“…These two abattoirs are about 18 km apart. This result is in agreement with the weak genetic structuring of Sb observed in Cameroon [ 12 ] and Côte d’Ivoire [ 15 ]. With only two sites, it is difficult to provide more general results on the genetic structure of this parasite species in Mali.…”

“…For instance, our study shows that the heterozygosity rate is higher for Sb than for Sc. Variations in heterozygosity have already been observed in previous studies between Sb and Sh in Cameroon [ 12 ] and in Côte d’Ivoire [ 15 ].…”