Application of endophytic bacteria for controlling anthracnose disease (Colletotrichum lindemuthianum) on bean plants

Over 100 endophytic bacterial isolates were isolated from surface-sterilised roots of the Fabaceae family in East Azerbaijan farms. These isolates were screened for their in vitro biocontrol activity against Colletotrichum lindemuthianum by dual culture technique using potato dextrose agar (PDA) medium. Eight bacterial isolates (Bacillus subtilis subsp. subtilis, Bacillus atrophaeus, B. tequilensis, B. subtilis subsp. spizizenii, Streptomyces cyaneofuscatus, S. flavofuscus, S. parvus, S. acrimycini) showed promising inhibition on mycelial growth of C. lindemuthianum , and thus, these isolates were selected for greenhouse experiments. The disease control rate using these selected endophytic bacteria was varied from 40 to 76.80% in greenhouse without any negative effects on different growth performance, suggesting that these selected endophytic bacteria are potential to be developed as biocontrol agents.     

A Survey on Distribution of Aspergillus Section Flavi in Corn Field Soils in Iran: Population Patterns Based on Aflatoxins, Cyclopiazonic Acid and Sclerotia Production

Soil isolates of Aspergillus section Flavi from Mazandaran and Semnan provinces with totally different climatic conditions in Iran were examined for aflatoxins (AFs; B and G types), cyclopiazonic acid (CPA) and sclerotia production. A total of 66 Aspergillus flavus group strains were identified from three species viz. Aspergillus flavus, Aspergillus parasiticus and Aspergillus nomius in both locations. A. flavus (87.9%) was found to be the prominent species followed by A. nomius (9.1%) and A. parasiticus (3.0%). Only 27.5% of A. flavus isolates were aflatoxigenic (B₁ or B₁ and B₂), out of which approximately 75% were capable to producing CPA. All the A. parasiticus and A. nomius isolates produced AFs of both B (B₁ and B₂) and G (G₁ and G₂) types, but did not produce CPA. Sclerotia production was observed in only 4 isolates of A. flavus among all 66 isolates from three identified species. A. flavus isolates were classified into various chemotypes based on the ability to produce aflatoxins and CPA. In this study, a new naturally occurring toxigenic A. flavus chemotype comprising of two strains capable of producing more AFB₂ than AFB₁ has been identified. A relatively larger proportion of aflatoxigenic A. flavus strains were isolated from corn field soils of Mazandaran province which indicate a possible relationship between high levels of relative humidity and the incidence of aflatoxin-producing fungi. The importance of incidence of Aspergillus section Flavi in corn field soils regard to their mycotoxin production profiles and crop contamination with special reference to climatic conditions is discussed.     

Novel nucleotide changes in mutational analysis of mitochondrial 12SrRNA gene in patients with nonsyndromic and aminoglycoside-induced hearing loss

Mitochondria have essential role in cellular energy metabolism and defects in their function lead to many metabolic diseases. Mitochondrial DNA (mtDNA) mutations have been associated with number diseases such as nonsyndromic and aminoglycoside-induced hearing loss. Mutational screening of entire 12SrRNA and tRNA ^{ser (UCN)} genes in 107 unrelated Iranian patients with amino glycoside-induced and nonsyndromic bilateral hearing loss by direct sequencing analysis method were performed. Twenty different homoplasmic sequence variants were identified; including fifteen common polymorphisms, two putatively pathogenic variants: m.921T>C and m.1005T>C, one 12SrRNA sequence variant m.739C>T and two nucleotides substitution; m.1245T>C and m.1545T>C. Deafness-associated mutation, m.1555A>G, was not found. In our patients we found the mutation 1005 was associated with R haplogroup. These finding show that m.1555A>G mutation is not important in our population. Nucleotide change, m.739C>T, previously reported with very low frequency. We suggested the variation of two nucleotides 1245 and 1545 that localized at conserved site of 12SrRNA may be new candidate for amino glycoside-induced and nonsyndromic hearing impairment associated mutations. However, aminoglycoside exposure is a risk factor for clinical phenotype appearance of these mutations.     

Introduction of some new endophytic bacteria from Bacillus and Streptomyces genera as successful biocontrol agents against Sclerotium rolfsii

Endophytic bacteria live inside plant tissues without causing disease and not only promote plant growth but can also protect plants against plant pathogens. During 2010–2011 crop years, some endophytic bacteria were collected and are then biochemically and molecularly identified (16srRNA) from bean farms of East Azarbaijan, Iran. Among these bacteria isolates, four isolates from Bacillus genera and four isolates from Streptomyces genera were selected for evaluation of their ability for biocontrol of Sclerotium rolfsii in laboratory and glasshouse conditions. Except one isolate named Streptomyces parvus, the rest of isolates could significantly inhibit mycelial growth in dual culture on PDA medium. All seven selected isolates showed significant inhibition in disease treatments in glasshouse experiments. Biological traits, such as length, wet and dry weight of roots and stems in endophytic bacterial treatment showed no differences with healthy control.     

Effects of Heracleum persicum ethyl acetate extract on the growth, hyphal ultrastructure and aflatoxin biosynthesis in Aspergillus parasiticus

The ethyl acetate extract of leaves, seeds and flowers of Heracleum persicum, a medicinal plant of Iran (family Apiaceae) inhibited growth and aflatoxin (AF) production of Aspergillus parasiticus. On the basis of total dry weight growth inhibition by the leaf extract ranged from 17.1 to 36.9 %, by the flower extract from 32.2 to 75.6 %, and by the seed extract from 27.5 to 74.9 %. Production of AFB₁ and AFG₁ was inhibited in a dose-dependent manner, with a reduction of 88.5–100 % at the highest concentration of 8,000 μg/ml tested. The flower extract decreased ergosterol content of hyphae most significantly. Electron microscopy further revealed structural defects in the treated A. parasiticus including disruption of cytoplasmic membranous compartments, detachment of plasma membrane from the cell wall, and disorganization of hyphal compartments. Collapsed hyphae without conidiation, shorter branches and undifferentiated hyphal tips were also evident. The results indicate that H. persicum extract exerts antifungal and anti-AF activities by disrupting plasma membrane integrity and permeability mainly through interference with ergosterol biosynthesis. These results show that H. persicum can serve as a potent and safe alternative for inhibiting toxigenic aspergilli growth and thus preventing AF contamination of foods and feeds.     

Necroptosis and RhoA/ROCK pathways: molecular targets of Nesfatin-1 in cardioprotection against myocardial ischemia/reperfusion injury in a rat model

Molecular Biology Reports - Nesfatin-1 as a new energy-regulating peptide has been known to display a pivotal role in modulation of cardiovascular functions and protection against...     

Interactions of anthropometric indices,rs9939609 FTO gene polymorphism and breast cancer: A case-control study

Contradictory results were reported on the effect of fat mass- and obesity-associated (FTO) gene and anthropometric measurements on breast cancer (BC). This study aimed to assess the interactions between rs9939609 polymorphism of FTO gene, anthropometric indices and BC risk in Iranian women. This case-control study was performed on 540 women including 180 women with BC and 360 healthy women in Tehran, Iran. Physical activity and dietary intakes were assessed by validated questionnaires. Data on sociodemographic and pathologic factors of the participants as well as their blood samples were collected. The rs9939609 FTO gene polymorphism was genotyped using the tetra-primer amplification refractory mutation system-polymerase chain reaction (T-ARMS-PCR). No significant association was found between BC and risk allele of FTO rs9939609 polymorphism after adjustments for the confounders. However, there was a significant association between rs9939609 polymorphism risk allele and BC risk in females with overweight, even after adjusting for age, family history of BC, abortion, BMI and the number of pregnancies (P < .05). The association was disappeared after further adjustments for lifestyle factors including smoking, alcohol consumption, calorie and macronutrients intake, and physical activity. The FTO gene polymorphism was associated with the risk of BC in overweight individuals. This association was influenced by environmental factors including diet, alcohol consumption and smoking. Future studies are required to confirm the association between the FTO gene and BC in overweight females and to identify the underlying mechanisms.     

Pretreatment with LEDs regulates antioxidant capacity and polyphenolic profile in two genotypes of basil under salinity stress

Protoplasma - In the present study, we evaluated a pretreatment with four LED light sources (red, blue, red + blue, and white) in two genotypes (green and purple) of basil on the growth...     

To compare PubMed Clinical Queries and UpToDate in teaching information mastery to clinical residents: a crossover randomized controlled trial

Purpose

To compare PubMed Clinical Queries and UpToDate regarding the amount and speed of information retrieval and users'' satisfaction.

Method

A cross-over randomized trial was conducted in February 2009 in Tehran University of Medical Sciences that included 44 year-one or two residents who participated in an information mastery workshop. A one-hour lecture on the principles of information mastery was organized followed by self learning slide shows before using each database. Subsequently, participants were randomly assigned to answer 2 clinical scenarios using either UpToDate or PubMed Clinical Queries then crossed to use the other database to answer 2 different clinical scenarios. The proportion of relevantly answered clinical scenarios, time to answer retrieval, and users'' satisfaction were measured in each database.

Results

Based on intention-to-treat analysis, participants retrieved the answer of 67 (76%) questions using UpToDate and 38 (43%) questions using PubMed Clinical Queries (P<0.001). The median time to answer retrieval was 17 min (95% CI: 16 to 18) using UpToDate compared to 29 min (95% CI: 26 to 32) using PubMed Clinical Queries (P<0.001). The satisfaction with the accuracy of retrieved answers, interaction with UpToDate and also overall satisfaction were higher among UpToDate users compared to PubMed Clinical Queries users (P<0.001).

Conclusions

For first time users, using UpToDate compared to Pubmed Clinical Querries can lead to not only a higher proportion of relevant answer retrieval within a shorter time, but also a higher users'' satisfaction. So, addition of tutoring pre-appraised sources such as UpToDate to the information mastery curricula seems to be highly efficient.     

Proteomics analysis of BHK‐21 cells infected with a fixed strain of rabies virus

Rabies is a neurotropic virus that causes a life threatening acute viral encephalitis. The complex relationship of rabies virus (RV) with the host leads to its replication and spreading toward the neural network, where viral pathogenic effects appeared as neuronal dysfunction. In order to better understand the molecular basis of this relationship, a proteomics study on baby hamster kidney cells infected with challenge virus standard strain of RV was performed. This cell line is an in vitro model for rabies infection and is commonly used for viral seed preparation. The direct effect of the virus on cellular protein machinery was investigated by 2‐DE proteome mapping of infected versus control cells followed by LC‐MS/MS identification. This analysis revealed significant changes in expression of 14 proteins, seven of these proteins were viral and the remaining were host proteins with different known functions: cytoskeletal (capping protein, vimentin), anti‐oxidative stress (superoxide dismutase), regulatory (Stathmin), and protein synthesis (P0). Despite of limited changes appeared upon rabies infection, they present a set of interesting biochemical pathways for further investigation on viral‐host interaction.