Biofabrication of zinc oxide nanoparticles from Melia azedarach and its potential in controlling soybean seed-borne phytopathogenic fungi.

Present study, report the biofabrication of zinc oxide nanoparticles from aqueous leaf extract of Melia azedarach (MaZnO-NPs) through solution combustion method and their novel application in preventing the growth of seed-borne fungal pathogens of soybean (Cladosporium cladosporioides and Fusarium oxysporum). The standard blotter method was employed to isolate fungi and was identified through molecular techniques. The characterization of MaZnO-NPs was carried out by UV-Vis spectroscopy, Fourier Transform Infrared Spectroscopy (FT-IR), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) equipped with Energy Dispersive Spectroscopy (EDS) and Transmission Electron Microscopy (TEM). The physicochemical characterization confirmed the particles were of high purity and nano size (30-40 nm) with a hexagonal shape. The synthesized MaZnO-NPs inhibited the growth of C. cladosporioides and F. oxysporum in a dose dependent manner. Biomass, ergosterol, lipid peroxidation, intracellular reactive oxygen species and membrane integrity determination upon MaZnO-NPs treatment offered significant activities there by confirming the mechanism of action against the test pathogens. In conclusion, due to the effectiveness of MaZnO-NPs in controlling the growth of C. cladosporioides and F. oxysporum, the synthesized MaZnO-NPs provides insight towards their potential application in agriculture and food industries.

Correction to: Bioprospection of actinobacteria derived from freshwater sediments for their potential to produce antimicrobial compounds.

Upon publication of this article [1], it was brought to our attention that Figs. 3, 4 and 5 are incorrectly presented in the original version of the article. The figures were inadvertently swapped in the original submission and published. Figure 3 should be treated as Fig. 5; Fig. 4 should be 3 and Fig. 5 should be Fig. 4.

Bioprospection of actinobacteria derived from freshwater sediments for their potential to produce antimicrobial compounds.

BACKGROUND: Actinobacteria from freshwater habitats have been explored less than from other habitats in the search for compounds of pharmaceutical value. This study highlighted the abundance of actinobacteria from freshwater sediments of two rivers and one lake, and the isolates were studied for their ability to produce antimicrobial bioactive compounds. RESULTS: 16S rRNA gene sequencing led to the identification of 84 actinobacterial isolates separated into a common genus (Streptomyces) and eight rare genera (Nocardiopsis, Saccharopolyspora, Rhodococcus, Prauserella, Amycolatopsis, Promicromonospora, Kocuria and Micrococcus). All strains that showed significant inhibition potentials were found against Gram-positive, Gram-negative and yeast pathogens. Further, three biosynthetic genes, polyketide synthases type II (PKS II), nonribosomal peptide synthetases (NRPS) and aminodeoxyisochorismate synthase (phzE), were detected in 38, 71 and 29% of the strains, respectively. Six isolates based on their antimicrobial potentials were selected for the detection and quantification of standard antibiotics using ultra performance liquid chromatography (UPLC-ESI-MS/MS) and volatile organic compounds (VOCs) using gas chromatography mass spectrometry (GC/MS). Four antibiotics (fluconazole, trimethoprim, ketoconazole and rifampicin) and 35 VOCs were quantified and determined from the methanolic crude extract of six selected Streptomyces strains. CONCLUSION: Infectious diseases still remain one of the leading causes of death globally and bacterial infections caused millions of deaths annually. Culturable actinobacteria associated with freshwater lake and river sediments has the prospects for the production of bioactive secondary metabolites.

Primary health care through family health programmes in field practice area Hadaba Shargia, Tripoli, Libya

The study looked at 3 465 people from 427 families who visited the family clinic in Hadaba Shargia, Tripoli, Libya, between December 1985 and November 1987. Total coverage for the multiphasic screening was 61.93%, out of which a majority were below the age of 15 years. The literacy rate was 64.18%. Most of those screened above the age of 15 were housewives. Of the families, 75.36% were living as nuclear families, with average family size of 8.1. Morbidity prevalence at the time of survey was 464.6 per 1 000, with a predominance of infectious diseases. Vaccination coverage was high for BCG, while moderate for DPT and polio and low for measles