Phylogenetical analysis of partially sequenced cytb gene of Haemoproteus columbae in pigeons and its pathological lesions in Egypt

Background: Haemoproteus columbae is widely distributed in tropical and subtropical regions, causing pseudomalaria in pigeons. Aims: The current study aimed to characterize the phylogenetic position of H. columbae in pigeons in Sharkia province, Egypt, based on partial sequencing of the cytb gene as the conserved regions. The “DNA barcode” of the cytb gene helps in designing primers that can be used to amplify the same gene in the related haemosporidians. Methods: One hundered blood samples were collected from domestic pigeons to identify H. columbae by polymerase chain reaction (PCR) and detect its relationship with other related haemosporidians. Results: Weight losses of 60%, anemia 40%, low growth rates 26.67%, diarrhea 76.67%, dyspnea 66.67%, some neurological symptoms 33.33%, and death 16.67% were observed in the studied birds. Post-mortem examinations showed chocolate-brown appearance of the livers of the birds and congested parenchymatous organs. Microscopical examinations of Giemsa stained blood smears (n=100) revealed a 30% infection rate. The obtained infection percentages were more pronounced in males (35.71%) than females (16.66%) and more in adults (57.14%) than young pigeons (15.38%). The present sequence of H. columbae was deposited in GenBank under accession No.: MH345964 and shows 100% identity with other related Haemoproteus species in the Sao Paulo Zoo, Brazil (KU131585 and KU131583) and the UK (KX832581 and KX832586). Conclusion: This study concluded that the accurate diagnosis of H. coulmbae infection in pigeons by specific primers will help with the early treatment of affected cases, especially in the presence of the immature forms, and can thus avoid the noticed clinical signs and the induced pathological lesions mentioned in our study.