Human study and experimental behavior of Schistosoma mansoni isolates from patients with different clinical forms of schistosomiasis

Conceição, Maria José; Lenzi, Henrique Leonel; Coura, José Rodrigues

doi:10.1016/j.actatropica.2008.05.007

Cited by 3 publications

(3 citation statements)

References 30 publications

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“…Morphological studies to assess changes in the reproductive system (Shaw and Erasmus, 1988;Neves et al, 2004) of adult worms are ongoing. Interestingly, morphological studies through scanning confocal laser microscopy for determination of egg viability (Holtfreter et al, 2011) and functional criteria such as labeling the eggs with the Hoechst 33258 fluorescent probe (Sarvel et al, 2006) and intestine histopathology (Conceição et al, 2008) can provide important information regarding this issue. Our findings indicate that the wild isolate from N. squamipes is susceptible to praziquantel.…”

Section: Discussionmentioning

confidence: 99%

Susceptibility of a Brazilian wild rodent isolate of Schistosoma mansoni to praziquantel in mice

Costa-Silva

Barros

Garcia

et al. 2012

Experimental Parasitology

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The therapeutic effects of praziquantel (PZQ) against a Schistosoma mansoni isolate derived from Nectomys squamipes (isolate R) and a susceptible isolate (BH) were analyzed in Swiss mice by fecal egg counting, adult worm reduction and oogram pattern. Infected mice were orally administrated with 62.5mg/kg (group 1), 125mg/kg (group 2), 250mg/kg (group 3) and 500mg/kg (group 4), each dose divided over 3 days (49, 50 and 51 days after infection). The data were analyzed using one-way analysis of variance (ANOVA). In regard to isolate R, no fecal eggs were observed with 250 mg/Kg and 500 mg/kg (p<0.05), whereas BH excretion reached zero with all doses. Mean worm burden reduction was significantly (p<0.05) higher at the two highest concentrations, regardless of isolate. At 62.5mg/kg, the percentage of immature eggs varied from 17% (isolate R) to 38% (isolate BH). At 125 mg/kg, the percentage of immature eggs varied from 20% (isolate R) to 16% (isolate BH). At 250 mg/kg, immature eggs dropped significantly to 1% (isolate R) and 4% (isolate BH). At 500 mg/kg, no immature eggs were found in isolate R, whereas in BH was 8%. No dosage significantly (p>0.05) affected the percentage of mature eggs, regardless of isolate. There was a large increase (p<0.001) in the percentages of dead eggs in all treated groups of 62% and 64% in groups 3 and 4, respectively (isolate R). The percentage of dead eggs rose from 34% (group 1) to 58% (group 3) in isolate BH. Although group 4 showed lowest increase in the percentage of dead eggs (46%), it was higher (p<0.001) compared to the 8% in the control. Our findings indicate that the wild isolate from N. squamipes is susceptible to PZQ.

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Section: Discussionmentioning

confidence: 99%

Susceptibility of a Brazilian wild rodent isolate of Schistosoma mansoni to praziquantel in mice

Costa-Silva

Barros

Garcia

et al. 2012

Experimental Parasitology

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“…These results indicated that PZQ is lethal to immature and mature eggs as it caused impairment of egg production which may be due to degenerative changes of the reproductive organs of female worms confirmed by many investigators. (Sarvel AK et al 2006, Conceiço MJ et al 2008, Holtfreter MC et al 2011) NTZ resulted in significant reduction in immature eggs, but not more than 18.5% compared to non-treated control. It could rise the percentage of dead eggs to 30.5% and mature eggs to 51% at different intervals of follow up.…”

Section: Discussionmentioning

confidence: 99%

Comparative parasitological and electron microscopic studies on the effects of Nitazoxanide and Praziquantel in Schistosoma mansoni-infected mice

El-Taweel¹,

El-Sayad²,

Helw³

et al. 2016

IJPT

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This study was designed to evaluate antischistosomal activity of Nitazoxanide (NTZ) in Schistosoma mansoni-infected mice compared to Praziquantel (PZQ). Fifty four infected mice were recruited into 3 groups, each of 18 mice. Group 1 was infected non-treated control. Group 2 was infected and then treated with PZQ 500 mg for two days, and group 3 was infected and treated with NTZ 100 mg/kg for seven days. Efficacy of drugs was assessed by Parasitological, and scanning electron microscopic studies. PZQ reduced (4.9%, 22.5% and 50.7%) of faecal eggs, (22%, 22.6% and 55.1%) of intestinal eggs, (20.4%, 44.3% and 46.7%) of hepatic egg counts and (27%, 45.1% and 64.9%) of total worm load whereas, NTZ reduced (4.9%, 22.5% and 50.7%),of faecal eggs, (22%, 22.6% and 55.1%) of intestinal eggs ,(20.4%, 44.3% and 46.7%) of hepatic egg counts and (27%, 45.1% and 64.9%) of total worm load at 1, 2 and 4 WPT, respectively. The percentages of dead eggs were more than 80% after PZQ treatment and only 30% after NTZ at 4 WPT. PZQ showed extensive tegumental damages in male and female worms more than NTZ at 2 WPT. Our findings concluded that Nitazoxanide showed weaker antischistosomal activity in animal models than praziquantel.

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“…Surveys on infection by Schistosoma mansoni that have been conducted in Minas Gerais since the 1970 decade have aimed to follow up the natural history of schistosomiasis with emphasis on (1) the pathogenicity of the etiological agent and its experimental behavior [ 1 ], (2) the host's characteristics and the influence of race, occupation, education level, age group, sex, specific treatment and frequency of contact with water streams for the activities of washing clothes, leisure, and fishing [ 2 , 3 ], and (3) environmental conditions, distribution of streams and their distance to homes, presence of Biomphalaria , and its infection rates and infectivity, with comparison of exposure to different isolates of the parasite [ 4 , 5 ]. The morbidity of infection has been evaluated through clinical and epidemiological studies in two field areas, in the Rio Doce and Jequitinhonha valleys of the state of Minas Gerais, Brazil.…”

Section: Introductionmentioning

confidence: 99%

Prevalence and Morbidity Data on Schistosoma mansoni Infection in Two Rural Areas of Jequitinhonha and Rio Doce Valleys in Minas Gerais, Brazil

et al. 2013

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Objective. This study aimed to compare the prevalence and morbidity data on Schistosoma mansoni infection in two rural areas: the Jequitinhonha valley (area 1) and the Rio Doce valley (area 2) in the state of Minas Gerais, Brazil, covering the period from 2007 to 2010. Material and Methods. The parasitological stool tests were based on the quantitative method of Kato modified by Katz et al. Three clinical forms were considered: type I—schistosomiasis infection, type II—hepatointestinal form, and type III—hepatosplenic form. Results. The prevalence of infection among inhabitants of area 1 was 22.9%, with 2.1% presenting the hepatosplenic form and two cases of schistosomal myeloradiculopathy. The infection prevalence rate in area 2 was 20.2%, with 3.3% presenting the hepatosplenic form. Conclusion and Recommendation. There was no difference in the prevalence and in the morbidity of Schistosoma mansoni infection between the two areas, but it was predominant in young men with a low intensity of infection. The cases of schistosomal myeloradiculopathy in area 1 can be highlighted: these emphasize that schistosomiasis should not be neglected in Brazil. The lack of infection control in both areas may be related to the poor sanitation system, the absence of previous treatment, and the reinfection process.

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Human study and experimental behavior of Schistosoma mansoni isolates from patients with different clinical forms of schistosomiasis

Cited by 3 publications

References 30 publications

Susceptibility of a Brazilian wild rodent isolate of Schistosoma mansoni to praziquantel in mice

Susceptibility of a Brazilian wild rodent isolate of Schistosoma mansoni to praziquantel in mice

Comparative parasitological and electron microscopic studies on the effects of Nitazoxanide and Praziquantel in Schistosoma mansoni-infected mice

Prevalence and Morbidity Data on Schistosoma mansoni Infection in Two Rural Areas of Jequitinhonha and Rio Doce Valleys in Minas Gerais, Brazil

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