Serological and Histopathological Investigation of Chlamydia abortus in Aborted Ewes in Wasit, Iraq

Chlamydia abortus is one of the most important pathogens, which causes a marked economic loss in small ruminants, in particular sheep, worldwide. This study aimed to detect the prevalence of C. abortus in the sera of aborted ewes in Wasit province, Iraq, using the enzyme-linked immunosorbent assay (ELISA), followed by the investigation of the main histopathological alterations that occurred in some organs of the dead newborns. Out of 180 tested samples by ELISA, 32.22% of the evaluated animals showed positive reactions to IgG antibodies toward C. abortus. Concerning the titers of the infection of seropositive ewes, there were significant increases in values of moderate level of antibody titer (55.17%), compared to mild (32.76%) and severe (12.07%) levels of infection. History data showed a significant variation (P<0.05) in the existence of seropositive ewes with other field animals. However, significant increases (P<0.05) were reported in the seropositive ewes existed with goat (91.38%) and cattle (84.48%), while significant decreases (P<0.05) were observed in positive ewes found in donkeys (8.62%), horses (3.45%), and camels (0%). Regarding the histopathology results, the findings of the small intestine showed marked necrosis of intestinal villous, hyperplastic tissues, and necrosis in some mucosal glands; however, in the liver, there was small ductal proliferation with mild portal fibrosis, necrotic debris, and focal areas of hemorrhage in the parenchyma. In conclusion, the findings of this study represent the first Iraqi data concerning Chlamydial detection in aborted ewes; however, further studies in other regions and animal species are necessary to know the actual prevalence of organisms and initiate active measures for control and prevention.