title: THE SUSCEPTIBILITY OF RECENT ISOLATES OF Schistosoma mansoni TO PRAZIQUANTEL.
abstract: BACKGROUND
  Schistosomiasis is a chronic disease caused by trematode flatworms of the genus Schistosoma and its control is dependent on a single drug, praziquantel (PZQ), but concerns over PZQ resistance have renewed interest in evaluating the in vitro susceptibility of recent isolates of Schistosoma mansoni to PZQ in comparison with well-established strains in the laboratory.
  
  
  METHODS
  The in vitro activity of PZQ (6.5-0.003 µg/mL) was evaluated in terms of mortality, reduced motor activity and ultrastructural alterations against S. mansoni.
  
  
  RESULTS
  After 3 h of incubation, PZQ, at 6.5 µg/mL, caused 100% mortality of all adult worms in the three types of recent isolates, while PZQ was inactive at concentrations of 0.08-0.003 µg/mL after 3 h of incubation. The results show that the SLM and Sotave isolates basically presented the same pattern of susceptibility, differing only in the concentration of 6.5 µg/mL, where deaths occurred from the range of 1.5 h in Sotave and just in the 3 h range of SLM. Additionally, this article presents ultrastructural evidence of rapid severe PZQ-induced surface membrane damage in S. mansoni after treatment with the drug, such as disintegration, sloughing, and erosion of the surface.
  
  
  CONCLUSIONS
  According to these results, PZQ is very effective to induce tegument destruction of recent isolates of S. mansoni.
authors.affiliation: Department of Parasitology, Centro de Pesquisas Aggeu Magalhães, Recife, PE, Brazil.
authors.forename: Adriana Maria B
authors.initials: AM
authors.lastname: Mendonça
authors.affiliation: Department of Parasitology, Centro de Pesquisas Aggeu Magalhães, Recife, PE, Brazil.
authors.forename: Ana Paula S
authors.initials: AP
authors.lastname: Feitosa
authors.affiliation: Department of Parasitology, Centro de Pesquisas Aggeu Magalhães, Recife, PE, Brazil.
authors.forename: Dyana L
authors.initials: DL
authors.lastname: Veras
authors.affiliation: Department of Parasitology, Centro de Pesquisas Aggeu Magalhães, Recife, PE, Brazil.
authors.forename: Thiago J
authors.initials: TJ
authors.lastname: Matos-Rocha
authors.affiliation: Department of Physiology and Pathology, Universidade de Federal da Paraíba, João Pessoa, PB, Brazil.
authors.forename: Marília G dos Santos
authors.initials: MG
authors.lastname: Cavalcanti
authors.affiliation: Department of Parasitology, Centro de Pesquisas Aggeu Magalhães, Recife, PE, Brazil.
authors.forename: Constança Clara G S
authors.initials: CC
authors.lastname: Barbosa
authors.affiliation: Department of Parasitology, Centro de Pesquisas Aggeu Magalhães, Recife, PE, Brazil.
authors.forename: Fábio A
authors.initials: FA
authors.lastname: Brayner
authors.affiliation: Department of Parasitology, Centro de Pesquisas Aggeu Magalhães, Recife, PE, Brazil.
authors.forename: Luiz C
authors.initials: LC
authors.lastname: Alves
mesh_terms: D000818:Animals; D004351:Drug Resistance; D005260:Female; D007814:Larva / Q000187:drug effects / Q000648:ultrastructure; D008297:Male; D021261:Parasitic Sensitivity Tests; D011223:Praziquantel / Q000494:pharmacology*; D012550:Schistosoma mansoni / Q000187:drug effects* / Q000302:isolation & purification* / Q000648:ultrastructure; D012556:Schistosomicides / Q000494:pharmacology*
chemical_list: D012556:Schistosomicides; D011223:Praziquantel