Detection of Colletotrichum falcatum causing red rot of sugarcane by enzyme-linked immunosorbent assay

Red rot disease of sugarcane caused by Colletotrichum falcatum Went is one of the most destructive diseases of sugarcane (Saccharum officinarum L.) worldwide. The pathogen spreads primarily through infected sugarcane setts and hence the use of disease-free setts is essential to prevent the disease. In order to develop immunological method for detection of C. falcatum, two proteins with molecular weights of 27 kDa and 45 kDa were purified from the mycelium of C. falcatum race Cf 05 and used as antigen source to raise polyclonal antibodies in NewZealand white rabbit. The developed polyclonal antibodies were tested for detection of C. falcatum by enzyme-linked immunosorbent assay (ELISA) and immunoblot analysis. The polyclonal antibodies specifically detected C. falcatum in extracts from infected plants, both in immunoblot and ELISA. The ELISA results showed that the developed polyclonal antibodies were highly specific to C.falcatum. The developed antibodies were very sensitive and could detect C.falcatum proteins even at a dilution of 1:50,000. Higher ELISA absorbance values were recorded even at an antigen dilution of 1:500. In western blot analysis, protein bands with molecular weights of 27 kDa and 45 kDa reacting to antisera raised against 27 kDa and 45 kDa mycelial proteins of C. falcatum, respectively, were detected in protein samples from red rot infected canes. The high specific reactivity and sensitivity of the antisera indicate its potential suitability for ELISA-based detection of C. falcatum.     

Alteration in nitrogen metabolism and plant growth during different developmental stages of green gram (<Emphasis Type="Italic">Vigna radiata</Emphasis> L.) in response to chlorpyrifos

Chlorpyrifos is a widely used broad-spectrum organophosphate insecticide in the agricultural practice. However, extensive use of this insecticide may lead to its accumulation in ecosystem, thus inducing the toxicity to crops and vegetables. To assess chlorpyrifos-induced toxicity in plants, we performed the experiment focusing on the growth and nitrogen metabolism of green gram plant (Vigna radiata L.). 20-days-old plants were subjected to chlorpyrifos at concentrations ranging from 0 to 1.5 mM through foliar spray in the field condition. Variation in root and shoot length, activities of nitrate reductase (NR) and content of nitrate, sugar, soluble amino acid and soluble protein were studied at preflowering (5 day after treatment, DAT), flowering (10 DAT) and postflowering (20 DAT) stages of plant development. Of the various concentrations of chlorpyrifos, 0.6 and 1.5 mM showed comparatively more severe toxicity to green gram plants by decreasing root and shoot length, nitrate, NR, soluble sugar and protein content where as at low concentration (0.3 mM) of chlorpyrifos proved stimulant for same parameter. Increase in soluble amino acid was observed in age and dose dependent manner. These results reflect strong parallelism between growth and biochemical activities of the model plant. Further lower dose of chlorpyrifos proved as stimulant where as at higher concentration proved detrimental for growth and nitrogen metabolism.     

Sorption of cadmium and zinc from aqueous solutions by water hyacinth (Eichchornia crassipes)

The water hyacinth (Eichchornia crassipes) has been successfully utilized for the removal of Zn(II) and Cd(II) as well as their admixture from samples of aqueous solutions. The growth of the plant after 16 days of exposure to the metal ions showed an increasing trend up to 2.5 ppm of Cd(II) and 6.0 ppm of Zn(II) concentrations, however, the growth became nondetectable or inhibited above these concentrations. The overall metal uptake by the plant was dependent upon the concentration of the metal and the duration of the exposure time. The metal uptake from a mixture of Cd(II) and Zn(II) was reflected by a rate constant quite different from those solutions containing only one metal ion. An analysis of metal in roots and tops of the plants showed that more Zn(II) was accumulated in the root when compared to Cd(II). However, the accumulation factor for the tops and the roots for Cd(II) and Zn(II) was higher than those obtained admixture of Zn(II) and Cd(II). The rate of metal mobility in the root was slower than that in the top of the plant for Zn(II) and Cd(II). A water hyacinth based system can be used to remove Cd(II) and Zn(II) from water/wastewater.     

Blind trials evaluating in vitro infectivity of Cryptosporidium oocysts using cell culture immunofluorescence

An optimized cell culture immunofluorescence (IFA) procedure, using the HCT-8 cell line, was evaluated in blind trials to determine the sensitivity and reproducibility of measuring the infectivity of flow-cytometry-prepared inocula of Cryptosporidium parvum oocysts. In separate trials, suspensions consisting of between 0% and 100% viable oocysts were prepared at the US Environmental Protection Agency, shipped to the American Water Laboratory, and analyzed blindly by cell culture IFA. Data indicated the control (100% live) oocyst suspensions yielded statistically similar results to cell culture dose-response curve data developed previously at the American Water Laboratory. For test samples containing oocyst suspensions of unknown infectivity, cell culture IFA analyses indicated a high degree of correlation (r2 = 0.89; n = 26) with the values expected by the US Environmental Protection Agency. Cell culture infectivity correlates well with neonatal mouse infectivity assays, and these blind validation trials provide credibility for the cell culture IFA procedure as a cost-effective and expedient alternative to mouse infectivity assays for determining in vitro infectivity of C. parvum oocysts.     

Implementation of a National Measles Elimination Program in Iran: Phylogenetic Analysis of Measles Virus Strains Isolated during 2010–2012 Outbreaks

Measles virus (MV) causes small and large outbreaks in Iran. Molecular assays allow identifying and the sources of measles imported from neighboring countries. We carried out a phylogenetic analysis of measles virus circulating in Iran over the period 2010–2012. Specimens from suspected cases of measles were collected from different regions of Iran. Virus isolation was performed on urine and throat swabs. Partial nucleoprotein gene segments of MV were amplified by RT-PCR. PCR products of 173 samples were sequenced and analyzed. The median age of confirmed cases was 2 years. Among all confirmed cases, 32% had unknown vaccination status, 20% had been vaccinated, and 48% had not been vaccinated. Genotypes B3 and D8 (for the first time), H1 and D4 were detected mainly in unvaccinated toddlers and young children. Genotype B3 became predominant in 2012 and was closely related to African strains. H1 strains were also found in small and large outbreaks during 2012 but were not identical to Iranian H1-2009 strains. A majority of the Iranian D4 strains during 2010–2012 outbreaks were linked to the D4 strain identified in the Pakistan in 2007. We identified a single case in 2010 belonging to D8 genotype with 99.7% identity to Indian isolates. Although the vaccination program is currently good enough to prevent nationwide epidemics and successfully decreased measles incidence in Iran, the fraction of protected individuals in the population was not high enough to prevent continuous introduction of cases from abroad. Due to increasing number of susceptible individuals in some areas, sustained transmission of the newly introduced viral genotype remains possible.     

Design of 11-residue peptides with unusual biophysical properties: induced secondary structure in the absence of water

A series of oligopeptides with β-forming and adhesive properties, were synthesized and analyzed for adhesion shear strength, secondary structure, and association properties. The sequences contained related hydrophobic core segments varying in length from 5 to 12 residues and flanked by di- or tri-lysine segments. Three remarkable peptides consisting of just 11 residues with hydrophobic core sequences of FLIVI, IGSII, and IVIGS flanked by three lysine residues gave the highest dry adhesion shear strength and displayed unusual biophysical properties in the presence and absence of water. KKKFLIVIKKK had its highest adhesion strength at 2% (w/v) at pH 12.0 and showed the highest adhesion strength after exposure to water (water resistance). Both KKKIGSIIKKK and KKKIVIGSKKK, at 4% (w/v) at pH 12.0, displayed nearly identical dry shear strength values to that with the FLIVI core sequence. The peptide with IGSII core, however, displayed a lower water resistance and the latter, IVIGS, showed no water resistance, completely delaminating upon soaking in water. These are the smallest peptides with adhesive properties reported to date and show remarkable adhesion strength even at lower concentrations of 0.2% (w/v), which corresponds to 1.6 mM. The FLIVI containing peptide adopted a β-sheet secondary structure in water while the IGSII- and IVIGS-containing sequences folded similarly only in the absence of water. Analytical ultracentrifugation studies showed that when the FLIVI sequence adopts β-structure in aqueous solution, it associates into a large molecular weight assembly. The random coils of IGSII and IVIGS showed no tendency to associate at any pH.     

Role of ghrelin axis in colorectal cancer: a novel association

Recently discovered orexigenic peptide, ghrelin, which is primarily produced by gastrointestinal tract, has been implicated in the malignant cell proliferation and invasion, presumably through an autocrine/paracrine mechanism. This study was aimed to identify the role of endogenously produced ghrelin in colorectal cancer progression. Malignant intestinal epithelial cells differentially over-express ghrelin receptors and produce more ghrelin as compared to normal human colonocytes, leading to their enhanced proliferative and invasive behavior. Though, systemically available endocrine ghrelin levels in patients with colorectal cancer do not exhibit significant correlation with any tumor stage or grade, however, locally produced autocrine tissue ghrelin strongly correlates both with advancing colorectal malignancy in a stage-dependent manner and BMI of the colorectal patients. We conclude that ghrelin might play an important role in promoting colorectal malignancy.     

Investigation of the electro-coagulation treatment process for the removal of total suspended solids and turbidity from municipal wastewater

In this work, raw municipal wastewater was electro-coagulated for the removal of total suspended solids (TSS), turbidity, and particulate BOD using stainless steel electrodes. The removal efficiency of TSS and turbidity is shown to depend on the amount of iron generated from the anode of the reactive electrode used in this study, when applying the lower currents of 0.05 A and 0.1A. For such lower currents, the results suggested that the removal is consistent with charge neutralization coagulation mechanism. When applying higher currents of 0.2 A, 0.4 A, and 0.8 A, the results suggested that the dominant removal mechanism is sweep-floc coagulation as the generated soluble ferrous ions are converted to insoluble ferric ions due to oxidation with chlorine generated during the electrochemical process at the higher currents. The highest TSS removal efficiency of 95.4% occurred at a current of 0.8A and contact time of 5 min. The effect of electro-coagulation on the removal of particulate BOD was shown to depend on the TSS removal efficiency.