EFFECT OF N-ACETYL-D-GLUCOSAMINE ON THE MIGRATION OF BRUGIA-PAHANGI MICROFILARIAE INTO THE HAEMOCOEL OF AEDES-AEGYPTI

Two strains of Aedes aegypti (L.), differing in their susceptibility to Brugia pahangi (Buckley & Edeson), were examined with regard to the effect on the proportion of microfilariae migrating from the mid-gut, of specific carbohydrate supplements in the infecting bloodmeal. N-Acetyl-D-glucosamine (GlcNAc), a sugar also present on the microfilarial sheath, significantly increased the migration rate. This enhancement is greater for the refractory strain of Ae.aegypti. The use of sucrose as a control sugar results in no enhancement of microfilariae migration. It is postulated that the GlcNAc is acting by blocking endogenous gut/peritrophic membrane carbohydrate binding proteins, which would normally inhibit microfilariae migration. Furthermore, there is a significant correlation whereby increasing loads of microfilariae ingested result in decreasing proportions migrating across the mid-gut.