Description, molecular characterization, and patterns of distribution of a widespread New World avian malaria parasite (Haemosporida: Plasmodiidae), Plasmodium (Novyella) homopolare sp. nov.

Abstract

Plasmodium (Novyella) homopolare, a newly described Plasmodium species, was found in a wide range of Passeriformes species in California, USA, and Colombia. This parasite infected more than 20% of the sampled bird community (N = 399) in California and was found in 3.6% of birds sampled (N = 493) in Colombia. Thus far, it has been confirmed in North and South America where it is present in numerous species of migratory and resident birds from six families. Based on 100% matches, or near-100% matches (i.e., ≤2-nucleotide difference), to DNA sequences previously deposited in GenBank, this parasite is likely also distributed in the Eastern USA, Central America, and the Caribbean. Here, we describe the blood stages of P. homopolare and its mtDNA cytochrome b sequence. P. homopolare belongs to the subgenus Novyella and can be readily distinguished from the majority of other Novyella species, primarily, by the strictly polar or subpolar position of meronts and advanced trophozoites in infected erythrocytes. We explore possible reasons why this widespread parasite has not been described in earlier studies. Natural malarial parasitemias are usually light and co-infections predominate, making the parasites difficult to detect and identify to species when relying exclusively on microscopic examination of blood films. The combined application of sequence data and digital microscopy techniques, such as those used in this study, provides identifying markers that will facilitate the diagnosis of this parasite in natural avian populations. We also address the evolutionary relationship of this parasite to other species of Plasmodium using phylogenetic reconstruction.

Avian haemosporidians from Neotropical highlands: Evidence from morphological and molecular data

“…(N.) homopolare lineage BAEBIC02 included identical sequences from 10 individuals belonging to three families of Passeriformes. This parasite lineage has been recorded previously in eight bird species from North America [40]. In contrast, P. (N.) unalis lineage TFUS06 included identical sequences from six individuals and appears to preferentially infect only members of the Turdidae family, particularly T. fuscater.…”

“…The Neotropical region offers a great opportunity for research on avian haemoparasites; this study found new host-parasite relationships, most likely due to high avian diversity associated with the uplift of the Andes, and the scarce number of studies on this topic in the Andean region [7][8][9][10][11][12][13][14][15]40,54,55]. An increasing number of lineages from avian Haemosporida have been recorded in the last decade around the world.…”

“…For the Andean highlands, until 2009, the presence of Plasmodium and Haemoproteus was evaluated using solely morphological diagnoses [11][12][13]56]. Since then, cytochrome b lineages have been used to explore the diversity of these parasites; three studies from Ecuador and Peru have been published to date which use only molecular tools [7,14,15] and three from Colombia describing the linkage between Plasmodium species and their molecular lineages [9,10,40].…”

“…The lineages associated with these parasites are likely to have a distribution throughout the Andean ecosystems because they were found infecting several host taxa with an Andean distribution. Previously 34 Haemoproteus and 21 Plasmodium species have been recorded in Neotropical birds [1,9,26,28,40,73] (Table S4), from which we found five species restricted to America H. Regarding the finding of a parasite with P. (N.) rouxi-like morphology, it is important to mention that P. (N.) rouxi has been reported mainly in Africa, Holarctic, the Oriental zoogeographic region [1], and one report in Brazil [73], so this would be the first report for the Andean mountains. Moreover, H. (P.) witti had only been reported for the type locality, Jamaica [1,37]; our results expand the distribution of this parasite to Colombia, and most likely Peru because the same lineage was also recorded there.…”

“…First a 1034 bp fragment was amplified using the Pacheco et al [3] protocol modified as reported by Mantilla et al [9]. If this fragment did not amplify, we used the nested PCR of Hellgren et al [39], modified as reported by Walther et al [40], to amplify a fragment of 488 bp. All reactions were accompanied by negative controls (H 2 O) and positive controls (samples from infected birds confirmed by microscopy); no false positives or negative reactions were found.…”