Reconstructing Colonization Dynamics of the Human Parasite Schistosoma mansoni following Anthropogenic Environmental Changes in Northwest Senegal.
PLoS Negl Trop Dis
; 9(8): e0003998, 2015 Aug.
Article
em En
| MEDLINE
| ID: mdl-26275049
ABSTRACT
BACKGROUND:
Anthropogenic environmental changes may lead to ecosystem destabilization and the unintentional colonization of new habitats by parasite populations. A remarkable example is the outbreak of intestinal schistosomiasis in Northwest Senegal following the construction of two dams in the '80s. While many studies have investigated the epidemiological, immunological and geographical patterns of Schistosoma mansoni infections in this region, little is known about its colonization history. METHODOLOGY/PRINCIPALFINDINGS:
Parasites were collected at several time points after the disease outbreak and genotyped using a 420 bp fragment of the mitochondrial cytochrome c oxidase subunit 1 gene (cox1) and nine nuclear DNA microsatellite markers. Phylogeographic and population genetic analyses revealed the presence of (i) many genetically different haplotypes at the non-recombining mitochondrial marker and (ii) one homogenous S. mansoni genetic group at the recombining microsatellite markers. These results suggest that the S. mansoni population in Northwest Senegal was triggered by intraspecific hybridization (i.e. admixture) between parasites that were introduced from different regions. This would comply with the extensive immigration of infected seasonal agricultural workers from neighboring regions in Senegal, Mauritania and Mali. The spatial and temporal stability of the established S. mansoni population suggests a swift local adaptation of the parasite to the local intermediate snail host Biomphalaria pfeifferi at the onset of the epidemic. CONCLUSIONS/SIGNIFICANCE:
Our results show that S. mansoni parasites are very successful in colonizing new areas without significant loss of genetic diversity. Maintaining high levels of diversity guarantees the adaptive potential of these parasites to cope with selective pressures such as drug treatment, which might complicate efforts to control the disease.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Schistosoma mansoni
/
Esquistossomose mansoni
/
Dinâmica Populacional
/
Meio Ambiente
/
Atividades Humanas
Tipo de estudo:
Prognostic_studies
Limite:
Animals
/
Humans
País/Região como assunto:
Africa
Idioma:
En
Revista:
PLoS Negl Trop Dis
Assunto da revista:
MEDICINA TROPICAL
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
Bélgica