Comparative Susceptibility of Different Biological Forms of Anopheles stephensi to Plasmodium berghei ANKA Strain

Abstract

BackgroundThere are varying degrees of compatibility between malaria parasite-mosquito species, and understanding this compatibility may be crucial for developing effective transmission-blocking vaccines. This study investigates the compatibility of different biological forms of a malaria vector, Anopheles stephensi, to Plasmodium berghei ANKA strain.MethodsSeveral biologically different and allopatric forms of A. stephensi were studied. Three forms were isolated from different regions of southern Iran: the variety mysorensis, the intermediate form and the native type form, and an additional type form originated from India (Beech strain).The mosquitoes were experimentally infected with P. berghei to compare their susceptibility to parasitism. Anti-mosquito midgut antiserum was then raised in BALB/cs mice immunized against gut antigens from the most susceptible form of A. stephensi (Beech strain), and the efficacy of the antiserum was assessed in transmission-blocking assays conducted on the least susceptible mosquito biological form.ResultsThe susceptibility of different biological forms of A. stephensi mosquito to P. berghei was specifically inter-type varied. The Beech strain and the intermediate form were both highly susceptible to infection, with higher oocyst and sporozoite infection rates than intermediate and mysorensis forms. The oocyst infection, and particularly sporozite infection, was lowest in the mysorensis strain. Antiserum raised against midgut proteins of the Indian Beech type form blocked infection in this mosquito population, but it was ineffective at blocking both oocyst and sporozoite development in the permissive but geographically distant intermediate form mosquitoes. This suggests that a strong degree of incompatibility exists between the mosquito strains in terms of midgut protein(s) acting as putative ookinete receptors.ConclusionsThe incompatibility in the midgut protein profiles between two biological forms of A. stephensi demonstrates a well-differentiated population structure according to geographical origin. Therefore, the design of potential transmission-blocking strategies should incorporate a more thorough understanding of intra-species variations in host-parasite interactions.

Age-dependance of pteridines in the malaria vector, Anopheles stephensi

“…Change in molecular structure may occur in geographical populations of some insects [23]. As in previous study, we found variation in molecular receptors on midgut epithelial cells of the geographical populations of A. stephensi [24]. However, existence of dissimilarity of pteridines molecules either among species or geographical population of mosquitoes is inevitable.…”

Purification and Partial Characterization of Agglutinin Lectin from Heamolymph of German Cockroach, Blattella germanica

“…Lectins are one of the pattern-recognition proteins concerned in innate immunity in insects ( 4 ). The presence of lectin activities in the heamolymph is more important for immunity of B. germanica against microbial pathogens.…”

“…Insects lack specific acquired nonself recognition systems such as antibody in vertebrates, and lectins molecules have main role of nonself recognition in the innate immune response (1)(2)(3)(4). Lectins can agglutinate foreign matter and thus become to be it more suitable for understanding.…”

Morphological and Molecular Characterization of ‘var. mysorensis’ form of Anopheles Stephensi

“…These species are closely related but reproductively isolated and have much differences in behavior [1,2,3]. For instance, many Anopheline mosquitoes that act as vector for malaria parasites are members of species complexes [4,5,6]. The vector and none vector mosquitoes of species complexes most often exist sympatrically.…”

“…mysorensis, intermediate and type, based on egg dimensions and the number of ridges on the egg oat [3]. Moreover, the type biological form is an e cient vector of malaria in urban areas but mysorensis is a poor vector (highly zoophilic) and limited only to rural areas, although it is susceptible to P. vivax VK210B [3,5,10]. The intermediate biological form is reported from rural and peri-urban areas with very little information about its vectorial capacity.…”