Work

Beyond the primer: anatomical site and cyst viability drive the molecular detection of Taenia saginata in slaughterhouse samples

Year: 2026

Type: article

Abstract: Background Bovine cysticercosis, caused by the larval stage of Taenia saginata , results in significant economic losses for the beef industry due to carcass condemnation. While routine post-mortem inspection is mandatory, visual diagnosis lacks specificity, particularly for degenerated or calcified cysts. This study evaluated the diagnostic performance of three conventional PCR assays—a widely used LSU rRNA target (328 bp), a previously described COX1 target (253 bp), and a novel COX1 target (428 bp) designed herein—as complementary tools to visual inspection. A total of 232 suspect macroscopic lesions (180 calcified cysts, 12 viable cysts, and 40 non-specific lesions) were collected from cattle slaughtered in Mato Grosso do Sul, Brazil. Results Our results demonstrated no statistically significant difference in diagnostic sensitivity among the three primer sets ( p > 0.05), indicating that molecular confirmation is not limited by primer selection. Instead, molecular detection was profoundly driven by cyst viability and anatomical location ( p < 0.001). While viable cysts yielded high positivity rates (up to 66.7%), detection in calcified lesions dropped to approximately 28.9% due to severe DNA degradation. Crucially, calcified hepatic lesions exhibited drastically lower PCR positivity (11.4%–15.2%) compared to those in the heart (46.0%–54.0%) and head muscles (50.0%–60.0%). Conclusions These findings indicate that visual inspection of hepatic tissue significantly overestimates the prevalence of T. saginata , likely due to the misclassification of non-parasitic granulomas. To improve diagnostic accuracy and prevent unwarranted carcass condemnations, molecular confirmation efforts and routine sanitary evaluations should prioritize suspect lesions in the heart and striated muscles over those found in the liver.

Source: BMC Veterinary Research

DOI: 10.1186/s12917-026-05722-2