Association mapping of spot blotch resistance in wild barley

Spot blotch, caused by Cochliobolus sativus, is an important foliar disease of barley. The disease has been controlled for over 40 years through the deployment of cultivars with durable resistance derived from the line NDB112. Pathotypes of C. sativus with virulence for the NDB112 resistance have been detected in Canada; thus, many commercial cultivars are vulnerable to spot blotch epidemics. To increase the diversity of spot blotch resistance in cultivated barley, we evaluated 318 diverse wild barley accessions comprising the Wild Barley Diversity Collection (WBDC) for reaction to C. sativus at the seedling stage and utilized an association mapping (AM) approach to identify and map resistance loci. A high frequency of resistance was found in the WBDC as 95% (302/318) of the accessions exhibited low infection responses. The WBDC was genotyped with 558 Diversity Array Technology (DArT®) and 2,878 single nucleotide polymorphism (SNP) markers and subjected to structure analysis before running the AM procedure. Thirteen QTL for spot blotch resistance were identified with DArT and SNP markers. These QTL were found on chromosomes 1H, 2H, 3H, 5H, and 7H and explained from 2.3 to 3.9% of the phenotypic variance. Nearly half of the identified QTL mapped to chromosome bins where spot blotch resistance loci were previously reported, offering some validation for the AM approach. The other QTL mapped to unique genomic regions and may represent new spot blotch resistance loci. This study demonstrates that AM is an effective technique for identifying and mapping QTL for disease resistance in a wild crop progenitor

Biosynthesis of silver nanoparticles from Citrobacter freundii as antibiofilm agents with their cytotoxic effects on human cells

Background: Nanomaterials have recently been identified for their potential benefits in the areas of medicine and pharmaceuticals. Among these nanomaterials, silver nanoparticles (Ag-NPs) have been widely utilized in the fields of diagnostics, antimicrobials, and catalysis. Objective: To investigate the potential utility of Citrobacter freundii in the synthesis of silver Nanoparticles (Ag-NPs), and to determine the antimicrobial activities of the Ag-NPs produced. Methods: Aqueous Ag+ ions were reduced when exposed to C. freundii extract and sunlight, leading to the formation of Ag-NPs. Qualitative microanalysis for the synthesized Ag-NPs was done using UVvis spectrometry, Energy Dispersive X-ray analysis (EDX), and scanning and transmission electron microscopy. The hydrodynamic size and stability of the particles were detected using Dynamic Light Scattering (DLS) analysis. The Ag-NPs’ anti-planktonic and anti-biofilm activities against Staphylococcus aureus and Pseudomonas aeruginosa, which are two important skin and wound pathogens, were investigated. The cytotoxicity on human dermal fibroblast cell line was also determined. Results: Ag-NPs were spherical with a size range between 15 to 30 nm. Furthermore, Ag-NPs displayed potent bactericidal activities against both S. aureus and P. aeruginosa and showed noticeable anti-biofilm activity against S. aureus biofilms. Ag-NPs induced minor cytotoxic effects on human cells as indicated by a reduction in cell viability, a disruption of plasma membrane integrity, and apoptosis induction. Conclusion: Ag-NPs generated in this study might be a future potential alternative to be used as antimicrobial agents in pharmaceutical applications for wound and skin related infections

Exploring the microbial diversity in Jordanian hot springs by comparative metagenomic analysis

A culture-independent approach was utilized in this study to reveal the microbial diversity in Jordanian hot springs represented by Ma\u27in and Afra hot springs. Water samples from Ma\u27in and Afra hot springs were collected in June 2015. The in situ temperature of water samples range was 38-59°C and the pH range was 7.4-8.4. The metagenome was extracted and analyzed using the next generation technology (bTEFAP ). A total of 314,310 sequences were parsed and 288,452 were then clustered. The sequences were predominated by bacteria (\u3e84%) and the relative abundance of archaea in each sample was \u3c1%. Eukaryotic microorganisms were detected but with varying abundances (0.6%-15%). Because most of the detected sequences were found to belong to the domain of bacteria (196,936 sequences out 288,452), the bacterial sequences were utilized for further microbial analyses. With respect to alpha and beta diversity, samples were rarefied to 30,000 sequences and bootstrapped at 10,000 sequences. The Shannon-Wiener Index curve plot reaches a plateau at approximately 3,000 sequences indicating that sequencing depth was sufficient to capture the full scope of microbial diversity. By examining the relative abundance of phyla detected in each sample, it appears that the biota of both Jordanian hot springs sampled are compositionally similar, with over 50% of the microbial community of each sample being comprised of the phylum Proteobacteria. The second most abundant phylum was the phylum Bacteroidetes which represents more than 13% in each sample. The phylum Firmicutes was also detected with a significant abundance. However, lower abundance of Deinococcus, Verrucomicrobia, Planctomycetes, and Chloroflexi was detected. A principal coordinate analysis plot was generated based upon the weighted UniFrac distance matrix. By utilizing Monte Carlo simulations, we were able to determine that there were no significant differences in the microbial diversity between each sample

Narghile Smoking among Jordanian Educated Working Women: Attitudes and Beliefs

Aims: We estimated the number of users of tobacco, particularly narghile (water pipe) among a sample of women working at a higher education institute in Jordan. We also investigated the attitudes of narghile smokers to their habit, together with their willingness to stop NS; and finally their awareness to oral health and their perceptions about the harmful effects of NS. Study Design: The study was a cross-sectional survey whereby the sample was conveniently selected from all the faculties, institutes and centres of the University. Place and Duration of Study: University of Jordan, Amman, Jordan during July 2011. Methodology: Data were collected by allowing the participants to complete a preprepared questionnaire privately. Statistical analysis was performed using the SPSS program. Results: Among the (96) participants, 24 ladies (25%) were smokers mostly (79.2%) of narghile. Demographic and social data of age, marital status, education level and number of children did not seem to affect smoking status. Friends and relatives were the main introducers and companions in narghile smoking (73.7%), and home was the main setting for the habit (68.4%). Whereas the hygienic practices related to narghile smoking were below the required level, narghile smokers reported a satisfactory level of oral health practices and were aware of the health risks associated with this habit. Conclusion: Narghile smoking is showing popularity among Jordanian educated working women who invariably have children. Social influences seem to be the major player in shaping women's smoking behavior, whereby close family and friends are the introducers and home is the favorable place for practicing the habit. Specific measures are needed to educate women, their husbands and children of the health hazards of narghile especially that children are adversely affected on different levels

Microbiological analysis, antimicrobial activity, and heavy-metals content of Jordanian Ma'in hot-springs water

Ma'in hot springs are known as sites of balneotherapy. However, little is known about their microbiology and chemistry. In this study, we aim at evaluating the antimicrobial activity of Ma'in hot-springs water (MHSW), studying its microbiology, and determining its physicochemical properties including the heavy metals content. Therefore, water samples were collected from Ma'in hot springs and tested for antimicrobial activity using agar diffusion method. Water was then cultivated on nutrient agar to isolate and identify the dominant bacteria by chemical and molecular methods. The identified strains were tested by cross streak method to evaluate their antimicrobial activity against different clinical and standard strains. Finally, water samples were chemically analyzed and the heavy-metals content was assessed. Results revealed that MHSW was not active against any of the clinical isolates. Nevertheless, MHSW was found to be active against five standard bacterial strains, namely, Staphylococcus epidermidis ATCC 12228 (inhibition zone: 20 mm), Staphylococcus aureus ATCC 29213 (inhibition zone: 19 mm), Micrococcus luteus ATCC 9341 (inhibition zone: 15.3 mm), and Bacillus cereus ATCC 11778 (inhibition zone: 12.3 mm). After cultivation of MHSW, five bacterial isolates were obtained and identified based on 16S rRNA gene analysis as new strains of Anoxybacillus flavithermus (identity percentage ranges between 96–99%). Physicochemical analysis revealed that the in situ temperature was 59 °C, pH was 7.8, salinity was 1.6 ppt, and dissolved oxygen was 3.8 mg l−1. In respect to heavy-metals content in MHSW, the following metals were present in the order: Cr (0.571 ppm) > Mn(0.169 ppm) > Fe (0.124 ppm) > Zn (0.095) > Cu(0.070 ppm) > Ni(0.058 ppm) > Cd (0.023 ppm) > Pb (0 ppm). Cd, Cr, Ni and Mn were found to be higher than permissible levels set by international organizations and countries. This study highlights new chemical and microbiological data about Ma'in hot springs. Keywords: Ma'in hot springs, Antimicrobial activity, Heavy metals, Water microbiology, Thermophilic bacteria, Balneotherap