OBJECTIVES: To optimise host-to-host transmission, digenean trematodes (parasites) synchronize their cercarial emission patterns with the aquatic activities of their vertebrate hosts. Schistosoma mansoni has a strictly diurnal shedding pattern involving two circadian chronotypes: an early shedding pattern with a mean peak occurring at 11:00 h and a late pattern with a mean peak occurring at 16:00 h. We analysed the cercarial emergence pattern of three schistosome populations from Oman where S. mansoni is resurgent. METHODS: For each schistosome population, the cercarial emergence pattern was assessed hourly over several days. Because we identified a new chronotype hitherto unknown in S. mansoni, we undertook taxonomic characterisation based on egg morphology and mitochondrial DNA sequence (COX1). RESULTS: Taxonomic characterisation revealed that the three schistosome populations belong to the species S. mansoni. Hence, this is the first report of this species exhibiting a nocturnal chronotype, with the mean peak occurring at 20:00 h. We interpreted the new chronotype as being the result of a lateral transfer of S. mansoni from humans to Rattus rattus. CONCLUSION: The cercarial emergence pattern of S. mansoni from Oman is circadian, exhibiting either a diurnal or a nocturnal phenotype.
OBJECTIVES: To optimise host-to-host transmission, digenean trematodes (parasites) synchronize their cercarial emission patterns with the aquatic activities of their vertebrate hosts. Schistosoma mansoni has a strictly diurnal shedding pattern involving two circadian chronotypes: an early shedding pattern with a mean peak occurring at 11:00 h and a late pattern with a mean peak occurring at 16:00 h. We analysed the cercarial emergence pattern of three schistosome populations from Oman where S. mansoni is resurgent. METHODS: For each schistosome population, the cercarial emergence pattern was assessed hourly over several days. Because we identified a new chronotype hitherto unknown in S. mansoni, we undertook taxonomic characterisation based on egg morphology and mitochondrial DNA sequence (COX1). RESULTS: Taxonomic characterisation revealed that the three schistosome populations belong to the species S. mansoni. Hence, this is the first report of this species exhibiting a nocturnal chronotype, with the mean peak occurring at 20:00 h. We interpreted the new chronotype as being the result of a lateral transfer of S. mansoni from humans to Rattus rattus. CONCLUSION: The cercarial emergence pattern of S. mansoni from Oman is circadian, exhibiting either a diurnal or a nocturnal phenotype.
Authors: Winka Le Clec'h; Frédéric D Chevalier; Ana Carolina A Mattos; Amanda Strickland; Robbie Diaz; Marina McDew-White; Claudia M Rohr; Safari Kinung'hi; Fiona Allan; Bonnie L Webster; Joanne P Webster; Aidan M Emery; David Rollinson; Amadou Garba Djirmay; Khalid M Al Mashikhi; Salem Al Yafae; Mohamed A Idris; Hélène Moné; Gabriel Mouahid; Philip LoVerde; Jonathan S Marchant; Timothy J C Anderson Journal: Sci Transl Med Date: 2021-12-22 Impact factor: 19.319
Authors: Kate A Rawlinson; Adam J Reid; Zhigang Lu; Patrick Driguez; Anna Wawer; Avril Coghlan; Geetha Sankaranarayanan; Sarah K Buddenborg; Carmen Diaz Soria; Catherine McCarthy; Nancy Holroyd; Mandy Sanders; Karl F Hoffmann; David Wilcockson; Gabriel Rinaldi; Matthew Berriman Journal: BMC Biol Date: 2021-12-02 Impact factor: 7.431