First report on the isolation of Chlamydia abortus from female dromedary camels with ovarian hydrobursitis

This study sought to isolate Chlamydia abortus (C. abortus) from camels with ovarian hydrobursitis (OVHB). To accomplish this goal, bursal tissue (n = 5) and bursal fluid (n = 6) samples were collected from 11 female dromedary camels with unilateral OVHB. A quantitative polymerase chain reaction (qPCR) was used for the preliminary detection of C. abortus in the infected samples. For the purpose of isolation, the prepared samples were inoculated into embryonated chicken eggs. Giemsa, Gimenez, and direct immunofluorescence (DIF) staining were used to detect any chlamydial inclusions in the infected yolk sacs. A second qPCR was then performed on the infected yolk sacs. The C. abortus gene was detected in 83.8% of the infected bursal tissue and bursal fluid samples. All the yolk sac smears treated with Giemsa, Gimenez, and DIF staining revealed intracytoplasmic inclusion bodies. Moreover, hemorrhagic patches, massive congestion, macerated yolk sacs, and dwarfism were observed in the infected chicken embryos. The C. abortus gene was also found in 63.6% of the infected yolk sacs. In conclusion, this is the first report of C. abortus isolation from female dromedary camels with OVHB, which represents a key step toward developing a practical vaccine and avoiding fertility problems in female camels.