<i>Polychromophilus</i> spp. (Haemosporida: Plasmodiidae): First Molecular Detection in Bat Flies From Brazilian Bats

Haemosporidian parasites exhibit a wide range of vertebrate hosts and corresponding insect vectors. Among mammals, bats host the most diverse array of haemosporidians, with seven genera identified. The genus Polychromophilus is exclusive to bats and is globally linked with hematophagous flies of the genera Basilia, Nycteribia, and Penicillidia as potential vectors. In Brazil, recent molecular studies have detected Polychromophilus in bats from the Cerrado and Atlantic Forest biomes; however, its vectors in the country remained unidentified. This study analyzed the haemosporidians infection of bat flies (24 Nycteribiidae and 43 Streblidae) collected from 13 bat species in the Legado das Águas. The bat-fly associations revealed highly specialized interactions, particularly among Basilia flies and Myotis bats. Notably, a rare interaction between Megistopoda proxima and Carollia perspicillata was also observed. Two specimens (3%) of nycteribiid flies (Basilia speiseri and Basilia lindolphoi), both collected from Myotis nigricans, tested positive for infection with Polychromophilus spp. Using cytb gene sequences, we examined the phylogenetic relationships of these Polychromophilus lineages with other global lineages. We identified two haplotypes, each clustering in distinct clades within the Polychromophilus murinus group. The presence of these parasites was further confirmed by sequencing of the clpc gene from the apicoplast genome and the nuclear asl gene. This study represents the first molecular detection of Polychromophilus spp. in a vector in Brazil, 50 years after its morphological description in the salivary glands of Basilia. These findings provide novel insights into the ecological networks in host-parasite-vector interactions in a preserved neotropical environment.