Mixed Theileria infections in free-ranging buffalo herds: implications for diagnosing Theileria parva infections in Cape buffalo (Syncerus caffer).
نویسندگان
چکیده
Buffalo-adapted Theileria parva causes Corridor disease in cattle. Strict control measures therefore apply to the movement of buffalo in South Africa and include mandatory testing of buffalo for the presence of T. parva. The official test is a real-time hybridization PCR assay that amplifies the V4 hypervariable region of the 18S rRNA gene of T. parva, T. sp. (buffalo) and T. sp. (bougasvlei). The effect that mixed T. parva and T. sp. (buffalo)-like infections have on accurate T. parva diagnosis was investigated in this study. In vitro mixed infection simulations indicated PCR signal suppression at 100 to 1000-fold T. sp. (buffalo) excess at low T. parva parasitaemia. Suppression of PCR signal was found in field buffalo with mixed infections. The T. parva-positive status of these cases was confirmed by selective suppression of T. sp. (buffalo) amplification using a locked nucleic acid clamp and independent assays based on the p67, p104 and Tpr genes. The incidence of mixed infections in the Corridor disease endemic region of South Africa is significant, while the prevalence in buffalo outside the endemic area is currently low. A predicted increase of T. sp. (buffalo)-like infections can affect future diagnoses where mixed infections occur, prompting the need for improvements in current diagnostics.
منابع مشابه
Development and evaluation of a real-time PCR test for detection of Theileria parva infections in Cape buffalo (Syncerus caffer) and cattle
متن کامل
The Hybrid II assay: a sensitive and specific real-time hybridization assay for the diagnosis of Theileria parva infection in Cape buffalo (Syncerus caffer) and cattle.
Corridor disease is an acute, fatal disease of cattle caused by buffalo-adapted Theileria parva. This is a nationally controlled disease in South Africa and strict control measures apply for the movement of buffalo, which includes mandatory testing for the presence of T. parva and other controlled diseases. Accurate diagnosis of the T. parva carrier state in buffalo using the official real-time...
متن کاملIdentification of Theileria parva and Theileria sp. (buffalo) 18S rRNA gene sequence variants in the African Buffalo (Syncerus caffer) in southern Africa.
Theileria parva is the causative agent of Corridor disease in cattle in South Africa. The African buffalo (Syncerus caffer) is the reservoir host, and, as these animals are important for eco-tourism in South Africa, it is compulsory to test and certify them disease free prior to translocation. A T. parva-specific real-time polymerase chain reaction (PCR) test based on the small subunit ribosoma...
متن کاملTheileriosis in South Africa: a brief review
East Coast fever caused by Theileria parva parva has been eradicated from South Africa, but tick-borne infections with other species of Theileria still occur, particularly in cattle and African buffalo (Syncerus caffer). One such infection is Corridor disease caused by T. parva lawrencei, which is controlled by restricting the movement of African buffalo. Other species reviewed are T. parva bov...
متن کاملSequence variation identified in the 18S rRNA gene of Theileria mutans and Theileria velifera from the African buffalo (Syncerus caffer).
The African buffalo (Syncerus caffer) is a natural reservoir host for both pathogenic and non-pathogenic Theileria species. These often occur naturally as mixed infections in buffalo. Although the benign and mildly pathogenic forms do not have any significant economic importance, their presence could complicate the interpretation of diagnostic test results aimed at the specific diagnosis of the...
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ورودعنوان ژورنال:
- Parasitology
دوره 138 7 شماره
صفحات -
تاریخ انتشار 2011