First report of molecular prevalence, phylogeny and hematological impact of Isospora sp. in common quails (Coturnix coturnix).

The present study investigates the molecular prevalence and phylogenetic characteristics of apicomplexan parasite, Isospora sp., in the blood samples of common quails (Coturnix coturnix) sampled from both wild (n = 237) and farmed (n = 230) populations across six districts (Bahawalnagar, Bahawalpur, Dera Ghazi Khan, Lahore, Layyah and Multan) in Punjab, Pakistan, during 2022 to 2023. Additionally, effect of parasite was documented on the complete blood count (CBC) of the hosts. Out of 467 quails tested, 10 (2.1 %) exhibited amplification of the 18S rRNA gene for Isospora sp. BLAST analysis of generated sequences has confirmed the identity of recovered PCR products as Isospora sp. Phylogenetic analysis revealed that Pakistani isolate clustered with Isospora sp. reported from birds, reptiles and mammals in various countries globally. A risk factor analysis indicated that the parasites did not vary significantly when compared between wild and farmed birds. Overall Isospora sp. prevalence varied between the sampling sites but was not limited to a particular bird sex. Significant CBC variations were recorded in infected birds (both wild and farmed) as compared to uninfected ones. This study provides the first documentation of Isospora sp. infection in Pakistani quails, underscoring the need for detailed investigations across different regions to enhance our understanding on Isospora sp. infection rates, their transmission, and impact on the host birds.