Browsing by Person "Musa, Sandrine"

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Blood parasites of vangas and other corvoidea on Madagascar
(2022) Magaña Vázquez, Regina; Woog, Friederike; Dinkel, Anke; Mackenstedt, Ute; Musa, Sandrine
Madagascar hosts a great diversity of bird species. This study focuses on the description of the diversity and prevalence of blood parasites (Haemosporida, trypanosomes and filarioid nematodes) in 131 blood samples of 14 species of Corvoidea, namely vangas (Vangidae), Coracina cinerea (Campephagidae), Dicrurus forficatus (Dicruridae) and Terpsiphone mutata (Monarchidae) found in primary rainforests on Madagascar. Blood parasites were detected using both molecular and microscopic methods. Multiplex PCR was used to detect mixed haemosporidian infections and nested PCR was used to describe a 479 bp fragment of the haemosporidian cytochrome b (cytb) gene. Furthermore, a 770 bp SSU rRNA fragment of trypanosomes, and, for microfilariae, a 690 bp fragment of 28S rRNA, as well as a 770 bp fragment of 28S rRNA, were amplified for identification using nested PCRs. Phylogenetic analyses were carried out for all sequences obtained from all blood parasite taxa. Over half of the samples (54.2%; n = 71) were infected with Haemosporida, whereas only 21.4% (n = 28) were infected with Trypanosoma and 5.3% (n = 7) contained filarioid nematode DNA. Fourteen of 56 blood smears contained some of the above-mentioned parasite taxa. The results corroborate the great diversity of blood parasites in the different bird species studied, especially in vangas. Vangas had the greatest diversity of parasites found, as well as the highest number of multiple infections, which may be due to their morphological diversity and resulting habitat use. Fifteen haemosporidian lineages, seven Trypanosoma and five filarioid nematode isolates were newly discovered in the avian species studied, particularly in the vangas. Members of the other Corvoidea families on Madagascar showed a lower susceptibility for avian haemosporidian parasites than vangas, which could be attributed to possible resistance against those parasites. The study confirmed the host specificity of some Haemosporida and microfilariae; however, it demonstrated that this was not the case for Trypanosoma.
Haemosporidian parasite infections of Malagasy Philepittidae and Nectariniidae are driven by phylogeny rather than ecology
(2023) Barbon, Hannah; Berthoud, Jean-Louis; Woog, Friederike; Musa, Sandrine
The nectarivorous common sunbird asity (Neodrepanis coruscans) is phylogenetically closely related to the frugivorous velvet asity (Philepitta castanea), yet it shares similar habitat and foraging behaviour as the Malagasy sunbirds (Cinnyris spp.). As ecological factors have been shown to influence blood parasite prevalence, it should be tested whether parasite abundance, prevalence and diversity of N. coruscans are more similar to the sunbirds than to its relative. Therefore, blood samples (n = 156) and smears (n = 60) were tested for different blood parasites (Haemosporida, trypanosomes, filarioid nematodes) using molecular and microscopic methods. High prevalence of haemosporidian parasites was observed in all bird taxa, with rates ranging from 23% in N. coruscans to 84.6% in C. notatus. The Malagasy Cinnyris spp. exhibited a high occurrence of mixed haemosporidian infections (>76%) with various specialized lineages. Within the Philepittidae family, no Haemoproteus infection was detected and just a few cases of mixed infections. Nectariniidae species predominantly had specialized haemosporidian lineages, while Philepittidae had infections mainly caused by generalist lineages. These findings emphasize the diverse range of blood parasites in Nectariniidae, while additionally highlighting the high diversity of trypanosomes and filarioid nematodes in Philepittidae. Additionally, several newly discovered haemosporidian lineages, Trypanosoma isolates and filarioid nematode isolates were identified. Notably, Philepittidae exhibited a lower prevalence of avian haemosporidian parasites compared to Nectariniidae, possibly due to potential resistance mechanisms. Despite N. coruscans sharing similar habitat and behavioural ecology with both Cinnyris spp., it closely resembles its relative, P. castanea, in all aspects of haemosporidian parasitism.
Raising the bar: genus-specific nested PCR improves detection and lineage identification of avian haemosporidian parasites
(2024) Musa, Sandrine; Hemberle, Theo; Bensch, Staffan; Palinauskas, Vaidas; Baltrūnaitė, Laima; Woog, Friederike; Mackenstedt, Ute
Avian haemosporidian parasites are useful model organisms to study the ecology and evolution of parasite-host interactions due to their global distribution and extensive biodiversity. Detection of these parasites has evolved from microscopic examination to PCR-based methods, with the mitochondrial cytochrome b gene serving as barcoding region. However, standard PCR protocols used for screening and identification purposes have limitations in detecting mixed infections and generating phylogenetically informative data due to short amplicon lengths. To address these issues, we developed a novel genus-specific nested PCR protocol targeting avian haemosporidian parasites. The protocol underwent rigorous testing utilizing a large dataset comprising blood samples from Malagasy birds of three distinct Passeriformes families. Furthermore, validation was done by examining smaller datasets in two other laboratories employing divergent master mixes and different bird species. Comparative analyses were conducted between the outcomes of the novel PCR protocol and those obtained through the widely used standard nested PCR method. The novel protocol enables specific identification of Plasmodium, Haemoproteus (Parahaemoproteus), and Leucocytozoon parasites. The analyses demonstrated comparable sensitivity to the standard nested PCR with notable improvements in detecting mixed infections. In addition, phylogenetic resolution is improved by amplification of longer fragments, leading to a better understanding of the haemosporidian biodiversity and evolution. Overall, the novel protocol represents a valuable addition to avian haemosporidian detection methodologies, facilitating comprehensive studies on parasite ecology, epidemiology, and evolution.