Screening of avian pathogens and genetic analysis of several mitochondrial genes in Dermanyssus gallinae populations in Türkiye.

The poultry red mite, PRM, Dermanyssus gallinae (De Geer, 1778), is widely regarded as the primary ectoparasite affecting egg-laying hens around the world. Besides direct feeding damage, the transmission of avian pathogens by PRMs is also a significant concern. Therefore, we aimed to screen the presence of 14 common avian pathogens in 32 PRM populations from egg-laying hens in Türkiye. As a result, Salmonella enterica (n=3), Tsukamurella paurometabola (n=18), and Avian fowlpox virus (n=4) (3 of which were wild-type APV) were detected in tested PRM populations. The results showed that the prevalence of avian pathogens in Turkish PRM populations was low. Nevertheless, these findings suggested that PRM can harbor disease-causing agents and may act as a vector in the spread of these pathogens in farms. In addition, four mitochondrial genes (mtDNAs) of D. gallinae, namely ND4, ND5, cytb, and atp6, were amplified, and obtained sequences were submitted to the GenBank database for the first time, which will allow further analyses. The genetic variation within cytb sequences of Turkish PRMs was the highest (1.01%), whereas intra-specific genetic distance was 1.7% when compared to a Chinese population (only available cytb sequence in the GenBank), indicating increasing genetic differentiation by distance. Last, more sequences belonging to mitochondrial genes are required to reveal their potential as molecular markers. [ABSTRACT FROM AUTHOR]