Molecular characterization and phylogenetic analysis of Pulex irritans (Siphonaptera: Pulicidae) fleas collected from sheep in Sivas Province, Türkiye

Flea infestation in sheep is a significant public health concern due to their widespread distribution worldwide and the transmission of flea-borne diseases. In this study, we aimed to identify and molecularly characterize P. irritans collected from sheep, using morphological, molecular, and phylogenetic analysis. Flea samples were collected from sheep on six farms in Sivas Province, Türkiye, between April and September 2024. The flea specimens were morphologically identified using identification keys. After total genomic DNA extraction and Polymerase Chain Reactions (PCR), the PCR products were sent for sequencing. This morphological study indicated that from the 250 adult fleas collected from sheep, 223 specimens (110 female and 113 male) belonged to the human flea, Pulex irritans. Also, mt-COI gene region Blast analysis results confirmed that all samples were P. irritans. Additionally, molecular analysis revealed a high sequence similarity (99.8 %) with P. irritans isolates from Iran and Australia, which are available in GenBank. Considering the relatively high frequency of presence of this ectoparasite in the sheep, further studies focused on the possibility of being a vector of pathogens and their distribution between these animals and humans are recommended. The results of this study can be used to identify flea-borne disease risks and develop effective control measures.