A Survey, morphological, molecular, and histopathological characteristics of Taenia pisiformis metacestode in Egyptian rabbits (Oryctolagus cuniculus)

Refaat Ras^1,2*Amanallah El-Bahrawy³Adel Abdelkhalek⁴Florica Morariu⁵Ayman N. Elsayed⁶Doaa S. Nouh⁷Anamaria Plesko⁸Marius Stelian Ilie^8*Manar AbdelMageed^10,9

• ¹Department of Microbiology and Parasitology, Faculty of Veterinary Medicine, Badr University in Cairo, Badr City, Egypt
• ²Department of Parasitology, Zagazig University Faculty of Veterinary Medicine, Zagazig, Egypt
• ³Department of Pathology, Faculty of Veterinary Medicine, University of Sadat City, El Sadat City, Egypt
• ⁴Department of Food Hygiene, Safety and Technology, Faculty of Veterinary Medicine, Badr University in Cairo, Badr City, Egypt
• ⁵Department of Biotechnologies,, University of Life Sciences “King Mihai I” from Timişoara, Timişoara, Romania
• ⁶Department of Zoology and Entomology, Faculty of Science (Boys), Al-Azhar University, Nasr City, Egypt
• ⁷Department of Anatomy and Embryology, Zagazig University Faculty of Veterinary Medicine, Zagazig, Egypt
• ⁸Department of Parasitology and Parasitic Disease, Faculty of Veterinary Medicine, University of Life Sciences “King Mihai I” from Timișoara, Timișoara, Romania
• ⁹Department of Pathology and Clinical Pathology, Faculty of Veterinary Medicine, Badr University in Cairo, Badr City, Egypt
• ¹⁰Department of Pathology, Zagazig University Faculty of Veterinary Medicine, Zagazig, Egypt

Introduction: Taenia pisiformis (T. pisiformis), the etiological agent of cysticercosis in rabbits, poses a considerable health risk to domestic lagomorphs and contributes to economic losses in rabbit farming. This study aimed to ascertain the prevalence, risk factors, and molecular characteristics of T. pisiformis in rabbits from three Egyptian regions: Badr City (Cairo Province), Sadat City (Monufia Province), and Assiut City (Assiut Province). Methods: A total of 150 samples were collected from both home-raised (n = 77) and farm-raised (n = 73) rabbits during the period from January to December 2024. Taenia pisiformis cysts were identified morphologically and histologically, with tissue samples processed using hematoxylin and eosin (H&E) staining. Molecular confirmation was performed via PCR targeting the Cytochrome oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 1 (nad1) mitochondrial genes, followed by sequencing and phylogenetic analysis. Statistical associations between infection and risk factors (age, location, season, and management system) were evaluated using chi-square and Fisher’s exact tests. Results: The overall infection prevalence was 21.3% (32/150), which was significantly higher in home-raised rabbits (31/77, 40.2%) compared to farm-raised rabbits (1/73, 1.3%; χ² = 31.5, P < 0.001). Infection rates were also strongly linked to season, with fall and winter showing higher prevalence. Cysts were mostly found in the mesentery and varied in number (1–5 per rabbit). Morphologically, the cysts contained a scolex with distinctive features, including suckers and rostellar hooks. Histology showed a thick cyst wall and characteristic tissue structures. Molecular analysis confirmed the parasite as Taenia pisiformis, with sequence similarities ranging from 97.64% to 100%, indicating a close relationship to global sequences. Discussion: These findings underscore the influence of management practices and seasonal factors on infection dynamics and highlight the importance of molecular tools in parasite surveillance.