high prevalence of drug resistance in animal trypanosomes without a history of drug exposure盛行的耐药性在动物锥不接触毒品的历史.pdfVIP

High Prevalence of Drug Resistance in Animal Trypanosomes without a History of Drug Exposure 1,2 1,3 2 1,3{ Simbarashe Chitanga , Tanguy Marcotty , Boniface Namangala , Peter Van den Bossche , Jan Van 1 1 Den Abbeele , Vincent Delespaux * 1 Institute of Tropical Medicine Antwerp, Antwerp, Belgium, 2 Department of Paraclinical Studies, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia, 3 Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort, South Africa Abstract Background: Trypanosomosis caused by Trypanosoma congolense is a major constraint to animal health in sub-Saharan Africa. Unfortunately, the treatment of the disease is impaired by the spread of drug resistance. Resistance to diminazene aceturate (DA) in T. congolense is linked to a mutation modifying the functioning of a P2-type purine-transporter responsible for the uptake of the drug. Our objective was to verify if the mutation was linked or not to drug pressure. Methodology/Principal Findings: Thirty-four T. congolense isolates sampled from tsetse or wildlife were screened for the DA-resistance linked mutation using DpnII-PCR-RFLP. The results showed 1 sensitive, 12 resistant and 21 mixed DpnII-PCR- RFLP profiles. This suggests that the mutation is present on at least one allele of each of the 33 isolates. For twelve of the isolates, a standard screening method in mice was used by (i) microscopic examination, (ii) trypanosome-specific 18S-PCR after 2 months of observation and (iii) weekly trypanosome-specific 18S-PCR for 8 weeks. The results showed that all mice remained microscopically trypanosome-positive after treatmen