Morphological and molecular characterization ofPlasmodium cathemerium(lineage PADOM02) from the sparrowPasser domesticuswith complete sporogony inCulex pipienscomplex

Avian malaria is a mosquito-borne disease caused byPlasmodiumspp. protozoa. Although these parasites have been extensively studied in North America and Eurasia, knowledge on the diversity ofPlasmodium, its vectors and avian hosts in Africa is scarce. In this study, we report on natural malarial infections in free-ranging sparrows (Passer domesticus) sampled at Giza Governorate, Egypt. Parasites were morphologically characterized asPlasmodium cathemeriumbased on the examination of thin blood smears from the avian host. Sequencing a fragment of the mitochondrial cytochromebgene showed that the parasite corresponded to lineage PADOM02. Phylogenetic analysis showed that this parasite is closely related to the lineages SERAU01 and PADOM09, both of which are attributed toP. cathemerium. Experimental infection ofCulex pipienscomplex was successful, with ookinetes first detected at 1-day post infection (dpi), oocysts at 4 dpi and sporozoites at 6 dpi. The massive infection of the salivary glands by sporozoites corroborates thatCx. pipienscomplex is a competent vector of PADOM02. Our findings confirm thatPlasmodiumlineage PADOM02 infects sparrows in urban areas along the Nile River, Egypt, and corroborate thatCx. pipienscomplex is a highly competent vector for these parasites. Furthermore, our results demonstrate that this lineage corresponds to the morphospeciesP. cathemeriumand notP. relictumas previously believed.