In vitro susceptibility of human Blastocystis subtypes to simeprevir

Introduction and aimBlastocystis is a common enteric parasite, having a worldwide distribution. Many antimicrobial agents are effective against it, yet side effects and drug resistance have been reported. Thus, ongoing trials are being conducted for exploring anti-Blastocystis alternatives. Proteases are attractive anti-protozoal drug targets, having documented roles in Blastocystis. Serine proteases are present in both hepatitis C virus and Blastocystis. Since drug repositioning is quite trendy, the in vitro efficacy of simeprevir (SMV), an anti-hepatitis serine protease inhibitor, against Blastocystis was investigated in the current study.MethodsStool samples were collected from patients, Alexandria, Egypt. Concentrated stools were screened using direct smears, trichrome, and modified Ziehl-Neelsen stains to exclude parasitic co-infections. Positive stool isolates were cultivated, molecularly subtyped for assessing the efficacy of three SMV doses (100,150, and 200 μg/ml) along 72 hours (h), on the most common subtype, through monitoring parasite growth, viability, re-culture, and also via ultrastructure verification. The most efficient dose and duration were later tested on other subtypes.ResultsResults revealed that Blastocystis was detected in 54.17% of examined samples. Molecularly, ST3 predominated (62%), followed by ST1 (8.6%) and ST2 (3.4%). Ascending concentrations of SMV progressively inhibited growth, viability, and re-culture of treated Blastocystis, with a non-statistically significant difference when compared to the therapeutic control metronidazole (MTZ). The most efficient dose and duration against ST3 was 150 µg/ml for 72 h. This dose inhibited the growth of ST3, ST1, and ST2 with percentages of 95.19%, 94.83%, and 94.74%, successively and viability with percentages of 98.30%, 98.09%, and 97.96%, successively. This dose abolished Blastocystis upon re-culturing. Ultra-structurally, SMV induced rupture of Blastocystis cell membrane leading to necrotic death, versus the reported apoptotic death caused by MTZ. In conclusion, 150 µg/ml SMV for 72 h proved its efficacy against ST1, ST2, and ST3 Blastocystis, thus sparing the need for pre-treatment molecular subtyping in developing countries.     

Wastewater as a Non-conventional Resource: Impact of Trace Metals and Bacteria on Soil,Plants, and Human Health

Abstract

In many arid and semi-arid regions, farmers are often obligated to informally use raw wastewater for irrigating their crops. The impacts of wastewater irrigation on soil, crops, and human health were investigated, regarding trace metals and bacteria. Cr, Cu, Fe, Ni, and Zn were detected in wastewater. Cr, Cu, and Zn accumulated in soil and crops in the order rocket?>?clover?>?cabbage. The Health Risk Index reported risk from Cr and Zn in rocket. Fecal coliforms in wastewater and crops were detected along with Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The frequency (%) was 86.7% (cabbage), 66.7% (rocket), and 43.3% (clover). The multiple antibiotic resistance index (0.503) rendered crops high risk source for contamination. The comprehensive pollution index classified wastewater severely polluted (≥2.01). Conclusions deduced crops alternative reservoirs for trace metals and human pathogens. Recommendations included implementation of low cost treatment methods, holding irrigation 5–15?days before harvest, assuming citric and acetic acids reducing solutions for trace metals, and suggested ofloxacin, amoxycillin/clavulanate, and amikacin antibiotics against reported bacteria.