Assessment of the occurrence of trypanocidal drug resistance in trypanosomes of naturally infected cattle in the Adamaoua region of Cameroon using the standard mouse test and molecular tools.

From May to November 2005, a study was carried out to assess the occurrence of trypanocidal drug resistance (DR) in trypanosomes of naturally infected cattle of the Adamaoua region of Cameroon. Two distinct Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) procedures were used together with an Allele specific-PCR (AS-PCR) and the standardized single-dose mouse test. Using the mouse test, 3 of the 13 Trypanosoma brucei isolates and all 14 tested Trypanosoma congolense isolates were resistant to ISM. However, only 11 of the 25 T. congolense isolates were diagnosed as resistant to ISM using the MboII-PCR-RFLP. Resistance to DA was identified in 1 of the 13 T. brucei isolates and all 11 T. congolense isolates which were tested with the mouse test. Using the AS-PCR or BclI-PCR-RFLP, 3 of the 13 T. brucei isolates and all 25 T. congolense isolates respectively were found resistant. The data presented in this study prove that DR is widespread in the Adamaoua Department of Cameroon. The problem appears to be more serious in T. congolense than in T. brucei. Appropriate measures need to be taken in order to control bovine trypanosomosis in this area.