Bulinus truncatus

About: Bulinus truncatus is a research topic. Over the lifetime, 414 publications have been published within this topic receiving 5640 citations.

Mitochondrial DNA Variations in Sibling Species of the Bulinus truncatus/tropicus Complex in Lake Albert, Western Uganda

Abstract: Thirty-nine snail samples morphologically conforming to the Bulinus truncatus/tropicus species complex were collected from 5 populations (Booma, Bugoigo, Piida, Toonya, and Walukuba) on Lake Albert, western Uganda. Analysis of patterns of sequence variations and evolutionary relationships within and between localities using a 612 bp fragment of the mitochondrial cytochrome oxidase subunit I (COI) gene revealed 5 unique haplotypes defined by 21 polymorphic sites. The Bayesian and medianjoining network phylogenetic reconstructions partitioned the haplotypes into 2 reciprocally monophyletic clades concordant with B. truncatus and B. tropicus separated by 18 mutational substitutions, corresponding to a 3.0% net sequence divergence. Sequence divergences between haplotypes ranged 0.2%-3.5%, and significant genetic differentiation was observed in 5 of the 6 population pairwise comparisons. The 2 sibling species were sympatric in only 1 locality, at Piida. Our results confirm the existence of 2 evolutionary lineages of the Bulinus truncatus/tropicus species in Lake Albert and underscore the utility of the mitochondrial COI gene in differentiating between sibling species of the B. truncatus/tropicus complex which are otherwise indistinguishable based on the shell morphology.

The molluscicidal properties of natural products from Ambrosia maritima.

Abstract: The molluscicidal properties of Damsin "I", Ambrosin "II", and tribromodamsin "III" were investigated against the intermediate hosts of schistosomiasis Biomphalaria alexandrina and Bulinus truncatus. Although Damsin was to some extent more toxic against B. alexandrina than the other two compounds, it was less toxic than them against B. truncatus after 24 hr exposure periods. There is a flex relationship between concentration of Damsin and exposure period to prodce 100% mortality. The molluscicidal potency of Damsin remained stable over a wide range of pH values, but was affected by storage, sunlight and river bed-mud. Structure-activity relationship is included.

The relative susceptibilities of juvenile and adult Bulinus globosus and Bulinus truncatus to the molluscicidal activities in the fruit of Ghanaian Blighia sapida, Blighia unijugata and Balanites aegyptiaca.

Abstract: The relative susceptibilities of juvenile (2- to 3-week-old) and adult (5- to 7-week-old) Bulinus globosus and Bu. truncatus to the molluscicidal activities of aqueous preparations of the powdered, dried fruits of Blighia sapida, Bl. unijugata and Balanites aegyptiaca were investigated under laboratory conditions. For the extract prepared from the freeze-dried, semi-ripe fruits of Bl. sapida, the concentrations killing 95% of the snails after an exposure for 24 h (LC95) were, respectively, 232.7 and 161.2 ppm for the juveniles and adults of Bu. globosus and 187.6 and 140.2 ppm for the juveniles and adults of Bu. truncatus. The corresponding values for Bl. unijugata were 136.9 and 98.7 ppm for Bu. globosus and 132.2 and 98.5 ppm for Bu. truncatus, respectively. Extracts of the freeze-dried, ripe fruit of Ba. aegyptiaca were much more active, however, giving LC95 of just 16.9 and 19.7 ppm for the juveniles and adults of Bu. globosus, and 14.2 and 12.0 ppm for the juveniles and adults of Bu. truncatus, respectively. In general, similar results were obtained when the fruit were oven-dried rather than freeze-dried but the potency of Balanites extracts produced from oven-dried fruit was relatively low. That the juvenile snails appeared less susceptible than the adults to the molluscicidal activity in each Blighia extract is interesting. This observation may have implications for snail control, in terms of the optimal frequency, timing and concentration of molluscicides applied in a particular habitat.

Focalisation de la transmission de Schistosoma haematobium au sein des périmètres irrigués de la vallée du Niger (Niger) : importance des facteurs malacologiques

Abstract: Background Currently, the control of urinary schistosomiasis is mostly based on mass treatment. Characterization of Schistosoma haematobium transmission could lead to adding new methods to the control strategy. Methods We carried out malacological and cercariometrical surveys in irrigated perimeters of the Niger River valley. A semi-monthly follow-up was performed in three main sites of human-water contact in a village located at the border of the irrigated perimeter. Bulinids were collected during 20 min; after identification based on the shell morphology, their parasites were characterized by isoelectrofocalisation. The cercariometrical technique by differential filtration was used to evaluate the density of cercariae in every site with two 20 litres samples of water collected at various periods of the day (9, 12, 15 and 18 h). Results In the arm of the river, the cercariometry never showed cercariae whereas only some Bulinus truncatus, all negative, were collected. In the channels, B. truncatus and B. globosus were observed and highest density was found during the dry season. Only B. truncatus was naturally infested. Homozygote BB phenotype (characteristic of S. haematobium) was observed in all positive molluscs. Using cercariometry, more than two third of cercariae were collected at 3:00 PM. Conclusion Transmission of S. haematobium was primarily focused in the irrigating channels during the dry hot season at the beginning of afternoon. These results should lead to improve the output of S. haematobium control methods within irrigated areas.