Schistosoma mansoni and S. haematobium: Miracidial host-finding behaviour is stimulated by macromolecules

• Published in: International journal for parasitology Vol. 25; no. 5; pp. 551 - 560
• Main Authors: Haberl, B., Kalbe, M., Fuchs, H., Ströbel, M., Schmalfuss, G., Haas, W.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-05-1995; Elsevier Science
• Subjects: Animal ethology; Animals; Biological and medical sciences; Biomphalaria - chemistry; Biomphalaria - parasitology; Chemotaxis; Fundamental and applied biological sciences. Psychology; glycoconjugates; Glycoconjugates - chemistry; Glycoconjugates - isolation & purification; host-finding; Host-Parasite Interactions; miracidium; Molecular Weight; Protozoa. Invertebrata; Psychology. Psychoanalysis. Psychiatry; Schistosoma haematobium; Schistosoma haematobium - physiology; Schistosoma mansoni; Schistosoma mansoni - physiology; Water - chemistry; Schistosoma mansoni; miracidium; Schistosoma haematobium; host-finding; glycoconjugates; Parasitic behavior; Exploratory behavior; Plathelmintha; Stimulation; Host; Glycoconjugate; Trematoda; Macromolecule; Helmintha; Invertebrata; Miracidium
• ISSN: 0020-7519; 1879-0135
• DOI: 10.1016/0020-7519(94)00158-K

The miracidia of
Schistosoma mansoni and
S. haematobium approach their host snails by increasing their rate of change of direction (RCD) in increasing gradieuts of snail-conditioned water (SCW), and they perform a turuback response. Both species show no significant directed chemotactical orientation towards their snail hosts. All three host-finding respeases (increased RCD, turnback response, and “repeated investigation”) seem to be stimulated in both species by a similar component of SCW, a macromolecular glycoconjugate with a molecular weight >30,000. The saccharide chains seem to be
O-glycosidically linked via serine and
N-acetylgalactosamine. The glycoconjugate is sensitive to lysozyme which may suggest that muramic acid as a gastroped-specific composent is involved in the recognition process. Small molecular components of SCW, as well as maguesium chloride offered as pure chemical, may cause a moderate increase in the RCD. Therefore a minor contribution of these components to the host-finding response of schistosome miracidia cannot be excluded. That schistosome miracidin respond to complex macromolecules as host cues may indicate an adaptation to avoid interference of the host-finding with ubiquitous small molecular mud components and it might enable the miracidia to achieve a high degree of host-specificity in their host-finding