Abortions in small ruminants represent a major concern in veterinary medicine due to their multifactorial etiology and the involvement of various zoonotic bacterial pathogens. This study aimed to investigate Listeria spp., Salmonella spp., and Chlamydophila abortus in the livers of aborted sheep fetuses exhibiting hepatitis using histopathological, immunohistochemical (IHC), cultural, and molecular (PCR) methods. The study material consisted of liver samples from 296 aborted sheep fetuses in Kars Province and surrounding villages, between 2016 and 2023. Hepatitis was identified in 100 (33.78%) of the aborted fetuses. IHC analysis revealed positivity in 7 (7%) samples for Listeria monocytogenes, 13 (13%) samples for Salmonella spp., and 6 (6%) samples for Chlamydophila abortus. Concurrent IHC positivity was detected in 3 samples for Salmonella spp. and L. monocytogenes and in 1 sample for Salmonella spp. and C. abortus.  Cultural analysis revealed positivity in 4 (4%) samples for Salmonella spp. and in 4 (4%) samples for L. monocytogenes, while simultaneous culture positivity for both agents was observed in 1 (1%) sample. Direct PCR revealed that 11% (n= 11) of the samples were positive for Salmonella spp., 6% (n= 6) for L. monocytogenes, and 5% (n= 5) for C. abortus. Overall, L. monocytogenes, Salmonella spp., and C. abortus were identified as important causes of sheep abortions with hepatitis lesions in the Kars region, and immunohistochemistry proved to be a rapid and reliable diagnostic method with high concordance to culture and PCR.

To Cite This Article: Dag S, Buyuk F, Celebi O, Akca D, Nuhoglu H, Yıldız A, Buyuk E, Coskun MR, Kengis M, Acar AM and Ersoy Y, 2026. Investigation of Listeria and Salmonella species and Chlamydophila abortus in aborted sheep fetuses exhibiting hepatitis lesions by immunohistochemical, cultural and molecular methods. Pak Vet J, 46(2): 429-437. http://dx.doi.org/10.29261/pakvetj/2026.031