Diversity and characterization of Candidatus Liberibacter asiaticus strains causing huanglongbing disease in Iran,based on two prophage loci

Huanglongbing (HLB), also known as citrus greening, is a destructive disease of citrus; it is considered a newly emerging disease which has spread to the Middle East and North Africa (MENA). In Iran, the disease was first found in 2009. In this study, two hypervariable prophage and phage‐related loci, bacteriophage repressor protein C1 (CLIBASIA_ 01645 locus) and prophage terminase gene (CLIBASIA_05610 locus), were used to determine the diversity and characterization of Candidatus Liberibacter asiaticus ( CLas) strains associated with HLB samples. Analyses of the CLIBASIA_01645 locus, characteristic of variable tandem repeat numbers (VTRNs), revealed the homogeneity of Iranian CLas isolates: However, this result showed two distinct genotypes (TRN < 10 and TRN > 10) of CLas in Iran. This is the first report documenting the presence of two differentially distributed genotypes of CLas in Iran. Sequence analysis of prophage terminase revealed the presence of two putative prophages (prophage I and prophage II) in the genome of CLas isolates of Iran. Frequency analysis of these two prophages by specific loci revealed the association between prophages populations, the development HLB symptoms and CLas genotypes and their interactions with another obligate symbiontic, HLB phytoplasma.     

Changes in flavonoid content and tyrosinase inhibitory activity in kenaf leaf extract after far-infrared treatment

The tyrosinase inhibitory activity of ethanolic extract of kenaf (Hibiscus cannabinus L.) leaf was evaluated before and after subjecting it to far-infrared (FIR) irradiation. The main component of the extract was analyzed as kaempferitrin (kaempferol-3,7-O-α-dirhamnoside). Prior to FIR irradiation, no inhibitory activity of the extract was detected in a tyrosinase assay. However, after FIR irradiation for 1h at 60°C, significant tyrosinase inhibitory activity (IC(50)=3500 ppm) was observed in it. In HPLC analysis, derhamnosylation products (kaempferol, afzelin, and α-rhamnoisorobin) were detected. The inhibitory activity may be due to the existence of derhamnosylation products. This study demonstrated that FIR irradiation can be used as a convenient tool for deglycosylation of flavonoid glycoside.     

Isolation of humic acid from the brown algaeAscophyllum nodosum,Fucus vesiculosus,Laminaria saccharina and the marine angiospermZostera marina

Recent discovery of humic acid (HA) in the free-living, brown algaPilayella littoralis has prompted a search for HA in other live plants. Marine algaeCodium fragile andMonostoma oxyspermum (greens),Chondrus crispus,Palmaria palmata andPolysiphonia lanosa (reds),Ascophyllum nodosum, Fucus vesiculosus andLaminaria saccharina (browns) andZostera marina (marine angiosperm) were investigated for their HA content. Only the brown algae and the marine angiosperm contained HA, which was extracted by a standard procedure augmented with necessary removal of alginic acid (where applicable). The isolated products were identified as HA by comparison of their analytical data, uv-visible, FTIR,¹H NMR spectra and morphologies with those of authentic HA isolated from municipal compost.Authors for correspondence     

Modified level of miR‐376a is associated with Parkinson's disease

Parkinson's disease (PD) is a frequent progressive neurodegenerative disorder. Impaired mitochondrial function is a major feature of sporadic PD. Some susceptibility or causative genes detected in PD are strongly associated with mitochondrial dysfunction including PGC1α, TFAM and GSK3β. microRNAs (miRNAs) are non‐coding RNAs whose altered levels are proven in disparate PD models and human brains. Therefore, the aim of this study was to detect modulations of miRs upstream of PGC1α, TFAM and GSK3β in association with PD onset and progress. In this study, a total of 33 PD subjects and 25 healthy volunteers were recruited. Candidate miRNA (miR‐376a) was selected through target prediction tools and literature survey. Chronic and acute in vitro PD models were created by MPP⁺‐intoxicated SHSY5Y cells. The levels of miR‐376a and aforementioned genes were assessed by RT‐qPCR. The expression of target genes was decreased in chronic model while there were dramatically up‐regulated levels of those genes in acute model of PD. miR‐376a was strongly altered in both acute and chronic PD models as well as PBMCs of PD patients. Our results also showed overexpression of PGC1α, and TFAM in PBMCs is inversely correlated with down‐regulation of miR‐376a, suggesting that miR‐376a possibly has an impact on PD pathogenesis through regulation of these genes which are involved in mitochondrial function. miR‐376a expression in PD‐derived PBMCs was also correlated with disease severity and may serve as a potential biomarker for PD diagnosis. This is the first study showing altered levels of miR‐376a in PD models and PBMCs, suggesting the probable role of this miRNA in PD pathogenesis. The present study also proposed TFAM and PGC1α as target genes of miR‐376a for the first time, through which it possibly can exert its impact on PD pathogenesis.     

Spatial and temporal spread of Citrus tristeza virus and its aphid vectors in the North western area of Morocco

First report of Citrus tristeza virus (CTV,Closterovirus) in Morocco datesback to 1961 in collections of citrus varieties. An exhaustive survey of citrus in the north of the country in 2009 revealed that CTV was spread all over the citrus production area. We attempted to evaluate the relative contribution of different aphid species in the spread of CTV disease in a Citrus reticulata orchard at the Loukkous region during 2 years (2012 and 2013). The overall CTV incidence estimated in the experimental site increased from 17.8% in 2012 to 31.15% in 2013. The most abundant aphid species colonising clementine trees was Aphis spiraecola and A. gossypii. Both aphid species reached their maximum peaks during the spring season. The rate of viruliferous aphids, estimated by real‐time RT‐PCR of single aphid, revealed that 35.4% of winged A. gossypii and 28.8% of winged A. spiraecola were viruliferous, confirming a high inoculum pressure in the area surrounding the experimental site. The aphid species Toxoptera citricida, which is able to transmit the aggressive isolates of CTV, was not found in the Loukkous region. The study of the spatial distribution of the CTV showed that in general, the disease was randomly distributed in the field. Overall, the results seem to indicate that A. spiraecola may be considered as the major aphid species contributing to CTV spread in our experimental conditions. The prevalence of mild strains in the region and the high level of aphid flight activity could explain the rapid evolution of CTV incidence in the experimental area.     

Chemoresistance in gliomas

Despite improved knowledge and advanced treatments of gliomas, the overall survival rate for glioma patients remains low. Gliomas comprise of significant cell heterogeneity that contains a large number of multidrug resistant (MDR) phenotypes and cancer stem cells (CSCs), a combination that may contribute to the resistance to treatment. This article reviews the MDR related genes, major-vault protein (MVP), anti-apoptotic protein (Bcl-2) and the molecular mechanisms that may contribute to chemoresistance, in addition to the upregulated MDR phenotypes present in CSCs that has recently been identified in gliomas. Moreover, future potential therapies that modulate MDR phenotypes and CSCs are also reviewed. An improved understanding of MDR may lead to a combined treatment, targeting both CSCs and their protective MDR phenotypes leading eventually to attractive strategies for the treatment of gliomas.     

Free radical scavenging abilities of flavonyl‐thiazolidine‐2,4‐dione compounds

Free radical scavenging activity of flavonyl‐thiazolidine‐2,4‐dione compounds has been evaluated using chemiluminescence, electron spin resonance spectroscopy with 5,5‐dimethyl‐1‐pyrroline‐1‐oxide as spin trap and DPPH (2,2′‐diphenyl‐1‐picrylhydrazyl) method. The examined compounds exhibited 28–50% scavenging superoxide anion radical ( ), 16.7–76.7% hydroxyl radical (HO^?) and 9–40% DPPH radical. Compounds containing carbonyl group in their structure can be considered as antioxidants with high relevance and great biological importance. Copyright © 2009 John Wiley & Sons, Ltd.     

Hematological and biochemical investigations on the effect of vitamin E and C on Oreochromis niloticus exposed to zinc oxide nanoparticles

This study was carried out to determine the LC₅₀ of zinc oxide nanoparticles (ZnONPs) on Oreochromis niloticus and to investigate the effect of vitamin E and C on hematological and biochemical alterations induced by two sublethal concentrations (1 and 2 mg/L) of ZnONPs. One hundred and eighty fish were used for studying the lethal concentrations of ZnONPs. For sublethal study two hundred and twenty-five males of O. niloticus were equally divided into five groups, control, the second and the third were treated with 1 and 2 mg/L ZnONPs respectively. The fourth and fifth were exposed to the same concentrations of ZnONPs plus vitamins E and C. The results revealed that the 96 h LC₅₀ of ZnONPs was 3.1 ± 0.4 mg/L. The sublethal study revealed the presence of normocytic normochromic anemia in groups (2, 3 and 5) along the experiment period. The 4th group showed normocytic normochromic anemia at the 7th day and microcytic hypochromic anemia at the 15th day. Leukocytosis, heterophilia, lymphopenia and monocytopenia were recorded at the 7th day in all treated groups compared with the normal control. At the 15th day heteropenia, lymphopenia and monocytopenia were reported in all treated groups. A significant increase in the serum levels of alkaline phosphatase, aminotransferases, urea, creatinine and erythrocytic nuclear and morphological abnormalities along the experimental periods in all treated groups compared with the normal control. Serum total protein and albumin levels were significantly decreased at the same period in the same groups. Addition of vitamin E and C to the diet (groups 4 and 5) significantly improved all measured parameters compared with groups (2 and 3) which treated with ZnONPs only.     

Evaluation of antimicrobial activity of selected plant extracts by rapid XTT colorimetry and bacterial enumeration

The aim of this study was to screen and evaluate the antimicrobial activity of indigenous Jordanian plant extracts, dissolved in dimethylsulfoxide, using the rapid XTT assay and viable count methods. XTT rapid assay was used for the initial screening of antimicrobial activity for the plant extracts. Antimicrobial activity of potentially active plant extracts was further assessed using the "viable plate count" method. Four degrees of antimicrobial activity (high, moderate, weak and inactive) against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, respectively, were recorded. The plant extracts of Hypericum triquetrifolium, Ballota undulata, Ruta chalepensis, Ononis natrix, Paronychia argentea and Marrubium vulgare had shown promising antimicrobial activity. This study showed that while both XTT and viable count methods are comparable when estimating the overall antimicrobial activity of experimental substances, there is no strong linear correlation between the two methods.