THE SUSCEPTIBILITY OF RECENT ISOLATES OF Schistosoma mansoni TO PRAZIQUANTEL

Introduction: 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. Material and 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. Conclusion: According to these results, PZQ is very effective to induce tegument destruction of recent isolates of S. mansoni

The susceptibility of recent isolates of Schistosoma mansoni to praziquantel

Submitted by Adagilson Silva ([email protected]) on 2017-09-01T12:20:05Z No. of bitstreams: 1 26910445 2016 men-sus.oa.pdf: 1648476 bytes, checksum: c33f7322cf741a45e6b2db16b6077dc1 (MD5)Approved for entry into archive by Adagilson Silva ([email protected]) on 2017-09-01T12:30:01Z (GMT) No. of bitstreams: 1 26910445 2016 men-sus.oa.pdf: 1648476 bytes, checksum: c33f7322cf741a45e6b2db16b6077dc1 (MD5)Made available in DSpace on 2017-09-01T12:30:01Z (GMT). No. of bitstreams: 1 26910445 2016 men-sus.oa.pdf: 1648476 bytes, checksum: c33f7322cf741a45e6b2db16b6077dc1 (MD5) Previous issue date: 2016Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Recife, PE, BrasilSchistosomiasis 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

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved