Response of drug resistant isolates of Schistosoma mansoni to antischistosomal agents

Kristen M. Drescher Eugene J. Rogers John I. Bruce Naftale Katz Luiz Candido de Souza Dias Gerald C. Coles About the authors

Abstract

The susceptibility of four isolates of Schistosoma mansoni (BH, MAP, MPR-1 and K) to four multiple doses of anti-schistosomal agents (hycanthone, niridazole, oxamniquire, and praziquantel) were evaluated in infected female Swiss albino mice. These schistosomal isolates had been maintained in the laboratory without further drug pressure for 20 to 30 generations. Multiple dosage regimens were used for each drug against each isolate of S. mansoni to generate ED50 (effective dose 50%) values. Results demonstrated that the K isolate is resistant to niridazole, the MPR-1 isolate to oxamniquine, and the MAP isolate to both hycanthone and oxamniquine. The BH isolate was susceptible to all drugs and was used as the reference isolate. All isolates were susceptible to praziquantel. The significance of the difference in response of the MPR-1 and MAP isolates is discussed. These results confirm the resistance of these isolates of S. mansoni of three schistosomicides and demonstrate that the resistance of these isolates are stable over long periods of time without exposure to drugs.

Schistosoma mansoni; drug-resistance; praziquantel; hycanthone; oxamniquine; niridazole; susceptibility; schistosome isolates (BH, MAP, K and MPR-1)


ABSTRACT

Response of drug resistant isolates of Schistosoma mansoni to antischistosomal agents

Kristen M. Drescher1

Eugene J. Rogers1

John I. Bruce1

Naftale Katz2

Luiz Candido de Souza Dias3

Gerald C. Coles4

University of Massachusetts at Lowell, Center for Tropical Diseases, Lowell, USA

FIOCRUZ, Centro de Pesquisas René Rachou, Belo Horizonte, Brasil

Universidade Estadual de Campinas, Departamento de Parasitologia, Campinas, Brasil

Ministry of Agriculture, Fisheries and Food, Central Veterinary Laboratory, New Haw, UK

The susceptibility of four isolates of Schistosoma mansoni (BH, MAP, MPR-1 and K) to four multiple doses of anti-schistosomal agents (hycanthone, niridazole, oxamniquire, and praziquantel) were evaluated in infected female Swiss albino mice. These schistosomal isolates had been maintained in the laboratory without further drug pressure for 20 to 30 generations. Multiple dosage regimens were used for each drug against each isolate of S. mansoni to generate ED50 (effective dose 50%) values. Results demonstrated that the K isolate is resistant to niridazole, the MPR-1 isolate to oxamniquine, and the MAP isolate to both hycanthone and oxamniquine. The BH isolate was susceptible to all drugs and was used as the reference isolate. All isolates were susceptible to praziquantel. The significance of the difference in response of the MPR-1 and MAP isolates is discussed. These results confirm the resistance of these isolates of S. mansoni of three schistosomicides and demonstrate that the resistance of these isolates are stable over long periods of time without exposure to drugs.

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Publication Dates

  • Publication in this collection
    01 June 2009
  • Date of issue
    Mar 1993
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