First Molecular Detection of Eimeria zaria in Iran: Targeting the ITS-2 Gene in Broiler Chicken Fecal Samples

Document Type : Original Articles

Authors

1 Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.

2 Department of Avian Health and Diseases, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.

10.32598/ijvm.20.1.1005828

Abstract

Background: Three newly identified Eimeria species (Eimeria lata, Eimeria nagambie, and Eimeria zaria) were first discovered in Australia. Initially recognized as unidentified genotypes (operational taxonomic units X, Y, and Z), these species have since been detected across multiple continents. Genomic analyses confirmed their distinction from classical Eimeria species, leading to their formal classification in 2021. Accurate characterization of these cryptic species requires advanced molecular tools and isolation of pure strains.
Objectives: Currently, controlling chicken coccidiosis continues to rely largely on vaccination and the use of anticoccidial medications. Since these drugs target Eimeria species differently and rarely provide similar effectiveness, and typically there is no cross-protection, accurate identification of regional species and strains is vital for selecting the right vaccines and treatments.
Methods: Fecal samples from 8 broiler farms in Mazandaran Province, Iran, were collected and confirmed to contain Eimeria microscopically. DNA was extracted from pooled oocysts of each farm, and species-specific polymerase chain reaction (PCR) targeting the internal transcribed spacer 2 gene was performed using designated primers. 
Results: E.lata and E. nagambie were not detected, but E. zaria was detected in two farms from Sari and Behshahr cities.
Conclusion: The samples were selectively collected from Mazandaran Province in northern Iran, a region known for its dense poultry production and humid climate, leading to high coccidiosis prevalence. This area’s significant role in the poultry industry makes it important for studying less-characterized Eimeria species. The findings reported in this study suggest the circulation of E. zaria, along with possibly two other species, in the region, emphasizing the need to revise Eimeria taxonomy and further investigate species diversity. 

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