Haemosporidian parasites in the ash-breasted Sierra finch (Geospizopsis plebejus): insights from an Andean dry forest population

Abstract

Haemosporidian genera Plasmodium, Haemoproteus and Leucocytozoon, responsible for avian malarial infections, are highly diverse and have a wide range of health effects and predictors, depending on the host and its environmental context. Here, we present, for the first time, detailed information on the identity, prevalence and parasitaemia of haemosporidians and other haemoparasites that infect the ash-breasted Sierra finch, Geospizopsis plebejus, in an Andean dry forest. We study the consequences of infection in the host body and health conditions and explore the environmental and intrinsic factors that influence infection status and parasitaemia. We conducted diagnoses by cytochrome b (cytb) sequencing and morphological identification, and estimated the levels of parasitaemia based on microscopy. We identified 6 cytb lineages infecting G. plebejus. Two of them were new lineages: Haemoproteus sp. GEPLE01 and GEPLE02. We also detected Haemoproteus sp. ZOCAP08, Haemoproteus sp. AMAVIR01, Plasmodium homopolare BAEBIC02 and Plasmodium cathemerium ZONCAP15. By microscopy, we detected Haemoproteus coatneyi, Haemoproteus erythrogravidus, P. homopolare and other unidentified species of Haemoproteus, Plasmodium, Babesia sp. and 1 microfilaria. We found no evidence of Leucocytozoon. Additionally, we detected several coinfections by sequencing and microscopy. The prevalence of haemosporidian infections was high (87.7%), and the mean parasitaemia was 61.65 infected cells per 10 000 erythrocytes examined. Prevalence and parasitaemia were higher for Haemoproteus than for Plasmodium. Haemoproteus sp. AMAVIR01 showed the highest prevalence (43.1%) and mean parasitaemia (94.39/10 000 erythrocytes) and might be associated with H. coatneyi. Immature individuals showed a lower prevalence than adults, supporting previous findings.

Keywords: Avian malaria; Babesia; Haemoproteus; Neotropics; Plasmodium; morphology.

Graphical abstract

Fig. 1.

Map of the study area. Sampling sites (1–4) are shown in yellow inside BPJ (red contour).

Fig. 2.

Phylogenetic position of the 4 lineages of Haemoproteus (in bold) found in the ash-breasted Sierra finch, Geospizopsis plebejus, among related Neotropical lineages. Bayesian posterior probabilities (Bpp) and maximum-likelihood bootstrap supports (MLb) are shown over nodes (Bbb/MLb). Each lineage includes: morphospecies or genus (if available); GenBank accession number (if available); MalAvi name and country where it was detected (CO, Colombia; CH, Chile; EC, Ecuador; ME, Mexico; PE, Peru; US, United States; NA, no information).

Fig. 3.

Phylogenetic position of the 2 lineages of Plasmodium (in bold) found in the ash-breasted Sierra finch, G. plebejus, among related Neotropical lineages. Bpp and MLb are shown over nodes (Bbb/MLb). Each lineage includes: morphospecies or genus (if available); GenBank accession number (if available); MalAvi name (if available) and country where it was detected (BR, Brazil; CO, Colombia; CR, Costa Rica; CH, Chile; EC, Ecuador; PE, Peru; US, United States).

Fig. 4.

Haemoparasite stages observed in the ash-breasted Sierra finch, G. plebejus. (A) Microgametocyte, and (B) macrogametocyte of Haemoproteus coatneyi, (C) microgametocyte, and (D) macrogametocyte of Haemoproteus erythrogravidus, (E) erythrocytic meronts, (F) gametocyte of Plasmodium homopolare and (G, H) erythrocytic meronts of Babesia sp. Scale bar = 10 μm. (I, J) Confections of Plasmodium and Haemoproteus. Scale bar = 10 μm. (K, L) Microfilaria. Scale bar = 20 μm. Black arrowheads: pigment granules, double black arrowheads: merozoites. White arrowheads, protrusions of the erythrocyte membrane as the most relevant characteristics of H. erythrogravidus. Giemsa-stained thin blood smears. (A–H) At high magnification 1000×; (I–L) at low magnification 400×.