Biology subjects

Senghor, B.

Publications and source records attributed to Senghor, B..

3 recordsLinked to original sources

bioRxiv2025

Rapid identification of Biomphalaria spp. and diagnosis of Schistosoma mansoni infestation using MALDI-TOF mass spectrometry

This study explores the use of Matrix-Assisted Laser Desorption/Ionization Time-of-Flight mass spectrometry (MALDI-TOF MS) to identify and differentiate Biomphalaria snails infected with the parasite S. mansoni, which causes schistosomiasis. The study was conducted on two snail species, Biomphalaria pfeifferi (collected in the field in Senegal) and Biomphalaria glabrata (a laboratory strain). The snails were infected in the laboratory with S. mansoni miracidia, and their infection was confirmed by cercariae emission tests and quantitative PCR. MALDI-TOF MS was then used to analyse proteins from infected and uninfected snails to identify spectral differences. Based on protein profiles, the results of MALDI-TOF mass spectrometry made it possible to accurately differentiate between S. mansoni-infected snails and uninfected snails. An increase in the number of peaks detected and their intensity was observed for the spectra of S. mansoni-infected snails compared to uninfected snails. The application of principal component analysis to these mass spectrometry profiles confirmed the discrimination between the two groups according to their infection status. In addition, specific discriminating peaks were identified for each snail species, allowing for the distinction of infected from uninfected snails. The present study revealed, for the first time, that MALDI-TOF MS appears to be a rapid, reliable, and specific tool for the diagnosis of schistosomiasis in snails, offering promising prospects for the surveillance and control of this disease in endemic areas. However, further work is needed to establish a MALDI-TOF MS reference spectra database specific to Schistosoma parasites and to standardise sample collection, storage, and preparation in order to apply this technique in the field.

zoology↗

bioRxiv2024

Evidences that host genetic background more than the environment shapes the microbiota of the snail Bulinus truncatus, an intermediate host of Schistosoma species.

Microbiota are increasingly recognized as key players in regulating host biological functions, influencing both the ecology and evolution of organisms. However, the factors shaping microbiota diversity and structure in natural environments remain underexplored, especially the relative importance of host genetics versus environmental factors. In this study, we address this gap using the freshwater snail Bulinus truncatus, an intermediate host for some human and animal Schistosoma parasites, as a model species. We developed 31 new microsatellite markers to assess the population structure of B. truncatus across 9 sites in Senegal. We then applied metabarcoding to characterize the diversity and structure of individual snail bacterial microbiota and environmental communities associated with each sampling site using environmental DNA. We also used molecular diagnostics to determine trematode infection status of B. truncatus individuals. By integrating these data through multiple regression on distance matrices (MRM) analyses, we quantified the influence of B. truncatus population genetics, spatial distribution, environmental bacterial communities, and infection status on the snails microbiota structure. Our results show that the genetic structure of B. truncatus populations, and to a lower extent geographic distribution, are the main factors explaining the snails microbiota compositions. Neither the environmental bacterial communities nor trematode infection status significantly contributed to microbiota structure. A portion of the variance in microbiota composition remains unexplained, suggesting that additional ecological or intrinsic factors might be involved. These findings provide new insights into the drivers of microbiota structure in natural populations and highlight the complexity of host-microbiota-environment interactions. Key-words: Bulinus truncatus, Microbiota, Spatial structure, Population genetics, Trematodes, Multiple regressions on distance matrices

ecology↗

bioRxiv2024

First evidence of a causal link between genetic variation and thermal adaptation in a schistosome host snail

Freshwater snails are pivotal in transmitting schistosomiasis, a tropical parasitic disease affecting over 150 million people. The adaptive potential of these snails is a critical factor in determining how climate change and other environmental factors influence disease transmission dynamics, yet it has remained unexplored. Bulinus truncatus is the schistosome intermediate host snail with the widest geographic distribution and therefore plays a pivotal role in determining the maximum range of urogenital schistosomiasis. In this study, we assessed the local adaptation capacity of B. truncatus to temperature through an integrative approach encompassing phenotypic, ecophysiological, and genomic data. Ten snail populations from diverse thermal environments were collected in three countries, with eight populations reared in a common garden. The F2 generation (total N= 2592) was exposed to eight chronic temperature treatments and various life-history traits were recorded for over 14 weeks. Subsequently, ecophysiological analyses were conducted on the ten last surviving snails per population. Genotyping the parental generation collected in the field using a genotyping-by-sequencing (GBS) approach, revealed 12,875 single nucleotide polymorphisms (SNPs), of which 4.91 % were potentially under selection. We observed a significant association between these outlier SNPs, temperature, and precipitation. Thermal adaptations in life-history traits were evident, with lower survival rates at high temperatures of warm- origin snails compensated for by higher reproduction rates. Cold-origin snails, on the other hand, exhibited higher growth rates adapted to a shorter growing season. Ecophysiological adaptations included elevated sugar and haemoglobin contents in cold-adapted snails. In contrast, warm-adapted snails displayed increased protein levels but also more oxidative damage. Furthermore, heightened phenoloxidase levels indicated a more robust immune response in snails from parasite-rich regions. The substantial local adaptation capacity of B. truncatus holds profound implications for its response to climate change, future schistosomiasis risk, and the effectiveness of schistosomiasis control measures. HighlightsO_LILocal adaptation influences species responses to climate change C_LIO_LIThe snail Bulinus truncatus showed a high thermal local adaptation (LA) potential C_LIO_LILA is apparent through variations in life history and ecophysiological traits C_LIO_LIWe identified a significant genetic basis underlying this LA C_LIO_LILA of the hosts could sustain schistosomiasis transmission under global warming C_LI

ecology↗