Sleeping with the enemy II: Expanding the ecological, molecular, and epidemiological knowledge of the tropical fowl mite, Ornithonyssus bursa (Berlese, 1888).

Ornithonyssus bursa (Berlese), the tropical fowl mite from the family Macronyssidae, is a hematophagous ectoparasite of birds with increasing importance in human and animal health. This study reports new cases of human parasitism associated with O. bursa in Brazil, involving direct contact with avian hosts or their nests. These cases include new geographic records in the states of São Paulo and Santa Catarina, and new associations with bird species, including the first known record in Amazona aestiva (Psittaciformes). Molecular analysis was performed on individual mites to characterize the species and investigate associated microorganisms. This study provides the first partial sequence of the cox1 gene for O. bursa and the first phylogenetic analysis for the family using this marker. Additionally, we report the first detection of Ehrlichia and Wolbachia in Brazilian specimens. Phylogenetic analyses based on the 16S rRNA sequences placed the Ehrlichia haplotype close to strains previously detected in Haemaphysalis spp. ticks and the Wolbachia haplotype within supergroup E. These findings expand our understanding of the ecological and microbial diversity of O. bursa, highlighting its public health relevance, and emphasize the need for further studies on its vector potential and evolutionary relationships.