Detection of chlamydial infection in Iranian turkey flocks

BACKGROUND: Avian chlamydiosis is a zoonotic disease of birds caused by the intracellular bacterium Chlamydia psittaci. Avian chlamydiosis leads to severe respiratory disease in young turkeys and egg production losses in layers. OBJECTIVES: Due to paucity of information about the prevalence of chlamydial infection in the turkey population in Iran, this study was conducted to detect chlamydial infection in some Iranian turkey flocks in different provinces. METHODS: A total of 177 samples were taken from turkeys and first verified as Chlamydiaceae by Chlamydiaceae-specific real-time polymerase chain reaction (real-time PCR) by detection of the 23S RNA gene of Chlamydiaceae (Ct values ranging from 34 to 38) and then positive samples were investigated for the presence of C. psittaci by a nested PCR. RESULTS: Seventeen of 177 samples (9.6%), corresponding to 13 farms of 48 examined farms were positive for Chlamydiaceae by real-time PCR. None of the positive samples were found to be C. psittaci in the nested PCR. CONCLUSIONS: This study showed no C. psittaci infection in the turkey population in Iran. We recommend investigation on other farm animals and wild populations for possible chlamydial infection and for better understanding of the source and epidemiology of this agent. Due to the challenges that exist for sampling and the relevant impact on reducing positive samples, investigation by parallel and complementary techniques may be useful in showing the true prevalence of infection in the target populations