Background & Aims: Malaria parasites attach to molecules on midgut surface of Anopheles mosquitoes to continue their life cycle. Here we try to evaluate the effect of anti-Anopheles midgut antibodies on coating these molecules and consequently blocking the transmission cycle of Plasmodium berghei inside their vectors.

 Materials & Methods: Balb/c mice were immunized with homogenized and deglycosylated midguts of female Anopheles stephensi type form (known as Beech strain) mosquitoes along with alum as adjuvant. Control mice received alum plus buffer or alum alone. Production of enough antibodies was confirmed with ELISA and the sedimentation of P. berghei infected blood mixed with sera from immunized or control mice was fed to Beech and another type form strain of Anopheles stephensi (originally from Bandar-Abbas, Iran) mosquitoes. Formation of oocysts on distal surface of midgut and their number and the presence of sporozoites was checked and compared between strains.

 Results: Oocyst rate and oocyst count mean of midguts and sporozoite rate of salivary glands of Beech strain was much lower (p<0.001) in test group (23.1% and 4) in contrast with controls of the same strain (57.8% and 35.5), but there was no meaningful difference between test and control groups of Bandar‑Abbas strain.

 Conclusion: With such different effects of antibodies raised against whole midgut antigens, it seems that for more effective immunizations against malaria transmission it is necessary to use more purified antigens with more homology between strains and species of malaria vectors.

  Source: Urmia Med J 2011: 22(4): 382 ISSN: 1027-3727