Green synthesis and bactericidal activities of isotropic and anisotropic spherical gold nanoparticles produced using Peganum harmala L leaf and seed extracts

Shape, size, and homogeneity affect the biological activity of gold nanoparticles (AuNPs) in nanomedicine and catalytic applications. Here we biosynthesized monodispersed isotropic and polydispersed anisotropic spherical AuNPs from leaf and seed extract broths of the medicinal plant Peganum harmala L. (Ph. L). Synthesized AuNPs were characterized by ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy (FT-IRS), field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM). The antimicrobial activity of AuNPs against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) human pathogens was also assessed. Leaf- and seed-derived AuNPs had characteristic localized surface plasmon resonances of 530 and 578 nm, respectively. TEM, FE-SEM, EDX, and XRD revealed the formation of elemental face-centered cubic spherical monodispersed isotropic AuNPs of average size 43.44 nm and polydispersed anisotropic AuNPs of average size 52.04 nm from leaf and seed extract broths, respectively. FT-IR revealed polyphenols and alcohols as responsible for AuNP capping, reduction, and protection. Anisotropic AuNPs showed no antibacterial activity, whereas isotropic AuNPs showed good inhibition of both E. coli and S. aureus. This represents a simple and ecofriendly protocol for the green synthesis of monodispersed isotropic spherical AuNPs, which may have value in a variety of applications.

Role of ELISA in early detection of Fasciola copro-antigens in experimentally infected animals

An immunodiagnostic sandwich enzyme-linked immunosorbent assay (ELISA) was performed for the detection of F. hepatica antigens in stool sample (copro-antigens) of experimentally infected animals (mice, rats and rabbits) over a period of 18 weeks using affinity-purified polyclonal antibodies raised against the whole adult F. gigantica. The test demonstrated fascioliasis in mice earlier than in rats or rabbits (4, 6 and 7 weeks post infection respectively) by detection of copro-antigens in stool samples. In all experimentally infected models, F. hepatica copro-antigens concentration showed continuous increase and mice samples had higher antigen concentration than rats and rabbits. Sensitivity of ELISA was significantly higher in mice (83.3%) than in rats and rabbits (75% and 66.7% respectively) and its specificity showed nearly similar results to sensitivity. From the previously obtained data, it could be concluded that ELISA proved to be a rapid, easy and sensitive test for diagnosing fascioliasis by detection of F. hepatica copro-antigens earlier than routine stool examination of Fasciola eggs.

Prevalence of Fasciola infection among school children in Sharkia Governorate, Egypt

This study was performed on 1350 school children from 9 different villages in Sharkia Governorate to investigate the real situation of endemicity of fascioliasis in the area. Stool examination using modified Kato thick smear method was performed to detect Fasciola infection and other parasites. Those with negative stool samples were examined serologically by ELISA test to detect anti-Fasciola IgG. All cases with positive anti-Fasciola IgG were further examined by circum-oval precipitin test (COPT) against viable S. mansoni eggs to exclude the crossly reacted Schistosoma infections. Sixty nine cases were found to pass Fasciola eggs in their stool samples (5.1%). Anti-Fasciola IgG was detected in the sera of 231 children (17.1%) using ELISA test. Eighty four out of the 231 children were found positive by COPT and were considered as schistosomal cases. The remaining 147 who gave negative COPT were considered as Fasciola infections. All of the 69 Fasciola positive stool cases were found positive by ELISA test and negative by COPT test. The sensitivity of stool analysis was 47% versus 100% sensitivity of ELISA, whereas the specificity of ELISA was 63%. The total number of Fasciola positive cases by ELISA and stool analysis were 147 cases among 1350 children indicating a prevalence of 10.9% among school children in Sharkia Governorate. This results highlighting the importance of health education and snail control in decreasing the high prevalence.