Histological analysis of morphostructural changes in bronchial and lung tissues in cattle fetuses during chlamydia infection in Perm Krai and Tyumen Oblast of the Russian Federation

Abstract

Abstract Between 2017 and 2019, 543 cattle (cows` aborted fetuses, stillborn calves) were studied in Perm Krai and Tyumen Oblast of the Russian Federation for the existence of chlamydia infection. Blood serum samples and fingerprints were analyzed from the animals, and a positive result was registered in 48 animals, which is about 9% of the population. Chlamydia was diagnosed on the basis of clinical signs of disease, passive hemagglutination test and microbiological studies. From 23 aborted and stillborn fetuses, biological material was taken for electron microscopic examination. In order to study pulmonary tissue injuries under the influence of chlamydia, a histological analysis of bronchi and lung aborted and stillborn calves was carried out. All three components of the mother-placenta-fertility system were found to be affected by bovine chlamydia. A characteristic pathological-anatomical sign of chlamydia in fetal death is the formation of common swelling, both tissue and cavity localization. Histological examination of organs and tissues traces changes in the general pathological nature of the developing vascular level, alternative processes, immunopathological reactions, systemic inflammatory changes in histochemical barriers. Morphological changes in the pulmonary tissue of the fetuses of different gestation terms indicate damage to the aero-hematic barrier with the possibility of respiratory disorders in the uterine period.