Kinetoplastid Biology and Disease

Background: Based on the recently sequenced gene coding for the Trypanosoma evansi (T. evansi) RoTat 1.2 Variable Surface Glycoprotein (VSG), a primer pair was designed targeting the DNA region lacking homology to other known VSG genes. A total of 39 different trypanosome stocks were tested using the RoTat 1.2 based Polymerase Chain Reaction (PCR). Results: This PCR yielded a 205 bp product in all T. evansi and in seven out of nine T. equiperdum strains tested. This product was not detected in the DNA from T. b. brucei, T. b. gambiense, T. b. rhodesiense, T. congolense, T. vivax and T. theileri parasites. The Rotat 1.2 PCR detects as few as 10 trypanosomes per reaction with purified DNA from blood samples, i.e. 50 trypanosomes/ml. Conclusion: PCR amplification of the RoTat 1.2 VSG gene is a specific marker for T. evansi strains, except T. evansi type B, and is especially useful in dyskinetoplastic strains where kDNA based markers may fail to amplify. Furthermore, our data support previous suggestions that some T. evansi stocks have been previously misclassified as T. equiperdum. Background Surra is an animal disease occurring in Africa, Asia and Latin America, caused by Trypanosoma evansi. T. evansi belongs to the subgenus Trypanozoon, together with T. equiperdum and T. brucei. The parasite can infect different host species and is mechanically transmitted by different biting flies such as Tabanidae and Stomoxys as well as by vampire bats such as Desmodus rotondus [1]. Camels and horses are very susceptible to the infection and death can occur within weeks or months. Moreover, T. evansi infections of cattle and buffaloes usually lead to a pronounced immunosuppression resulting in an increased susceptibility to other opportunistic diseases such as Pasteurella and anthrax [2]. Diagnosis of a T. evansi infection usually starts with clinical symptoms or the detection of antibodies to T. evansi. Conclusive evidence of T. evansi infection, however, relies on detection of the parasite in the blood or tissue fluids of infected animals. Unfortunately, parasitological techniques cannot always detect ongoing infections as the level of parasitaemia is often low and fluctuating, particularly during the chronic stage of the disease [3]. Published: 17 September 2004 Kinetoplastid Biology and Disease 2004, 3:3 doi:10.1186/1475-9292-3-3 Received: 01 June 2004 Accepted: 17 September 2004 This article is available from: http://www.kinetoplastids.com/content/3/1/3 © 2004 Claes et al; licensee BioMed Central Ltd. This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.