Anti-Malaria Aldolase polyclonal Antibody [HRP]

Blood parasites can impact host fitness and can, thus, act as selective agents in their host's evolution. The melanocortin system linked to colouration of vertebrates may infer higher parasite resistance via pleiotropic properties of the genes involved. Black Sparrowhawks (Accipiter melanoleucus) are colour polymorphic (dark and light morph adults) and distributed clinally in South Africa, with more dark morphs in the Southwest where the breeding season coincides with the rainy season. There, dark morphs have lower infections of haemosporidian parasitesHaemoproteus nisi, suggesting a higher parasitic resistance. Thus, it is hypothesized that the morph distribution may be an adaptive response to coping with varying parasite prevalence associated with rainfall levels, which may regulate the parasites' invertebrate vectors. This hypothesis assumes a fitness cost of high parasite burden, which could be specifically important during the energy-demanding breeding season. To explore this, we (1) quantified Black SparrowhawkH. nisiinfections across South Africa, and explored (2) breeding performance and apparent annual survival of adults, and (3) nestling body condition in Cape Town in relation to infection levels. In contrast to the predictions, we found that parasite prevalence did not vary across the country, we found no fitness costs of higher infection levels for breeding birds, and also nestling body condition was independent of infection levels. Thus, we found no support for our hypothesis. Black Sparrowhawk polymorphism is unlikely to be driven by an adaptive function linked to dealing with higher infections withH. nisiin regions with wetter breeding seasons.

BackgroundThe pathogenesis of Plasmodium falciparum malaria is related to the ability of parasite-infected erythrocytes (IEs) to adhere to the vascular endothelium (cytoadhesion/sequestration) or to surrounding uninfected erythrocytes (rosetting). Both processes are mediated by the expression of members of the clonally variant PfEMP1 parasite protein family on the surface of the IEs. Recent evidence obtained with laboratory-adapted clones indicates that P. falciparum can exploit human serum factors, such as IgM and alpha (2)-macroglobulin (alpha M-2), to increase the avidity of PfEMP1-mediated binding to erythrocyte receptors, as well as to evade host PfEMP1-specific immune responses. It has remained unclear whether PfEMP1 variants present in field isolates share these characteristics, and whether they are associated with clinical malaria severity. These issues were investigated here.MethodsChildren 1-12 years reporting with P. falciparum malaria to Hohoe Municipal Hospital, Ghana were enrolled in the study. Parasites from children with uncomplicated (UM) and severe malaria (SM) were collected. Binding of alpha M-2 and IgM from non-immune individuals to erythrocytes infected by P. falciparum isolates from 34 children (UM and SM) were analysed by flow cytometry. Rosetting in the presence of IgM or alpha M-2 was also evaluated. Experimental results were analysed according to the clinical presentation of the patients.ResultsClinical data from 108 children classified as UM (n=54) and SM cases (n=54) were analysed. Prostration, severe malaria anaemia, and hyperparasitaemia were the most frequent complications. Three children were diagnosed with cerebral malaria, and one child died. Parasite isolates from UM (n=14) and SM (n=20) children were analysed. Most of the field isolates bound non-immune IgM (33/34), whereas the alpha M-2-binding was less common (23/34). Binding of both non-immune IgM and alpha M-2 was higher but not significant in IEs from children with SM than from children with UM. In combination, IgM and alpha M-2 supported rosette formation at levels similar to that observed in the presence of 10% human serum.ConclusionsThe results support the hypothesis that binding of non-immune IgM and/or alpha M-2 to IEs facilitates rosette formation and perhaps contributes to P. falciparum malaria severity.