Plasmodium (Novyella) nucleophilum from an Egyptian Goose in São Paulo Zoo, Brazil: microscopic confirmation and molecular characterization

ABSTRACT

Plasmodium (Novyella) nucleophilum was identified using microscopy and PCR, in an Egyptian Goose(Alopochen aegyptiacus) that died in São Paulo Zoo, Brazil. This parasite is characterized by elongated gametocytes, small meronts with scant cytoplasm, less than eight merozoites and mainly for having all the stages appressed to the nuclei of infected erythrocytes. Additionally, Plasmodium (Haemamoeba)sp. was identified by microscopy in the same blood sample. The latter parasite lacks nucleophilic blood stages and is characterized by large roundish trophozoites, each with a large prominent centrally collated vacuole. This co-infection was not confirmed by PCR amplification of the mitochondrial cytochrome b(cytb) gene and sequencing; only one Plasmodium sp. cytb sequence was detected in the blood sample. Since parasitemia of P. nucleophilum (2.4%) was much higher than that of P. (Haemamoeba) sp. (0.2%),PCR may have favored the amplification of the cytb sequence of the former. Phylogenetic analysis is inagreement with this conclusion because the reported cytb sequence was positioned in the same branch of sequences of several Novyella species. This is the first assignment of the mitochondrial cytb gene sequence to P. nucleophilum...