Induction of systemic resistance by mixtures of fungal and endophytic bacterial isolates against <Emphasis Type="Italic">Pythium aphanidermatum</Emphasis>

The efficacy of eight fungal and ten endophytic bacterial isolates were tested for their ability to inhibit the growth of Pythium aphanidermatum, the causal agent of chilli damping-off. In vitro studies revealed that Trichoderma viride (TVA) and endophytic Pseudomonas fluorescens (EBL 20-PF) showed the highest inhibition of mycelial growth (71.5%; 76.7%) of P. aphanidermatum. Both the antagonists were compatible with each other and they were tested alone and together in vivo for the control of P. aphanidermatum. Besides, the induction of defense-related enzymes such as peroxidase (PO), polyphenoloxidase (PPO), phenylalanine ammonia-lyase (PAL), PR-protein like β-1, 3-glucanase and the accumulation of phenolics in chilli seedlings due to the application of bioagents were also studied. Combined application of talc-based formulation of bio-agents and challenge inoculated with P. aphanidermatum recorded maximum induction of defense-related enzymes, PR-proteins and accumulation of phenolics compared with individual application. This study suggest that the increased induction of defense-related enzymes (four to fivefold) and phenolic content (sixfold) due to the combination treatment of bioagents might have involved in the reduction of damping-off incidence and in turn increased the plant growth and yield of chilli.     

The dynamics of interconverting D- and E-forms of the HIV-1 integrase N-terminal domain

The N-terminal domain (NTD) of HIV-1 integrase adopts two inter-converting forms (D- and E-) due to their specific coordination of a Zn²⁺ ion by an HHCC motif. Mutational studies on NTD have suggested the importance of conformational transition in regulating the functions of tetramers and dimers of HIV-1 integrase. This study explores the stability and dynamics of native NTD forms and the conformational transition between D- and E-forms using molecular dynamics simulations elucidating their role in regulation of viral and host DNA integration. Simulation of native forms of NTD revealed stable dynamics. Transition studies between D- and E-forms using conventional molecular dynamics simulations for 50 ns partially revealed conformational change towards the target during D- to -E simulation (the extension of α1-helix), which failed in the E- to -D simulation. This could be attributed to the existence of the D-form (?1,945.907 kCal/mol) in higher energy than the E-form (?2,002.383 kCal/mol). The conformational transition pathway between these two states was explored using targeted molecular dynamics simulations. Analysis of the targeted molecular dynamics trajectories revealed conformations closer to the experimentally-reported intermediate form of an NTD during the transition phase. The role of Met22 in stabilizing the E-form was studied by simulating the E-form with Met22Ala mutation, revealing a highly dynamic α1-helix as compared to the native form. The present study reveals the significant role of the Zn²⁺ ion-coordinated HHCC motif and its interaction with Met22 as the basis for understanding the biological implications of D- and E-forms of the NTD in regulating integration reaction.     

Insertion-deletions burden in copy number polymorphisms of the Tibetan population

BACKGROUND:

Many studies have been conducted to identify either insertions-deletions (inDels) or copy number variations (CNVs) in humans, but few studies have been conducted to identify both of these forms coexisting in the same region.

AIMS AND OBJECTIVES:

To map the functionally significant sites within human genes that are likely to influence human traits and diseases.

MATERIALS AND METHODS:

In this report, we describe an inDel map in the 1051 Tibetan CNV regions obtained through CNV genotyping using Affymetrix Genome-wide single nucleotide polymorphism 6.0 chip. InDel polymorphisms in these copy number polymorphism regions were identified with a computational approach using the 2500 deoxyribonucleic acid sequences obtained from the 1000 Genome Project.

RESULTS:

The study identified a total of 95935 inDels that range from 1 bp to several bps in length which were found scattered across regulatory regions, exons and in introns of genes underlying the CNVs. A study on the distribution of inDels revealed that the majority of inDels were found in coding regions of the genome than the noncoding, while within the genes, inDels in intron regions were more followed by exonic regions and finally the regulatory regions.

CONCLUSION:

Study of inDels in CNV regions contribute to the enhanced understanding of the role played by the two variations and their collective influence on the genome. Further, a collection of these inDel genetic markers will aid in genetic mapping, further understanding of the phenotypic variability, identification of disease genes and in detecting novel CNVs.     

Determination of MIC Distribution of Arbekacin,Cefminox, Fosfomycin,Biapenem and Other Antibiotics against Gram-Negative Clinical Isolates in South India: A Prospective Study

Objectives

To determine the in vitro activity of antibiotics, including arbekacin, cefminox, fosfomycin and biapenem which are all still unavailable in India, against Gram-negative clinical isolates.

Methods

We prospectively collected and tested all consecutive isolates of Escherichia coli, Klebsiella spp., Pseudomonas aeruginosa and Acinetobacter spp. from blood, urine and sputum samples between March and November 2012. The minimum inhibition concentration (MIC) of 16 antibiotics was determined by the broth micro-dilution method.

Results

Overall 925 isolates were included; 211 E. coli, 207 Klebsiella spp., 153 P. aeruginosa, and 354 Acinetobacter spp. The MIC₅₀ and MIC₉₀ were high for cefminox, biapenem and arbekacin for all pathogens but interpretative criteria were not available. The MIC₅₀ was categorized as susceptible for a couple of antibiotics, including piperacillin/tazobactam, carbapenems and amikacin, for E. coli, Klebsiella spp. and P. aeruginosa. However, for Acinetobacter spp., the MIC₅₀ was categorized as susceptible only for colistin. On the other hand, fosfomycin was the only antibiotic that inhibited 90% of E. coli and Klebsiella spp. isolates, while 90% of P. aeruginosa isolates were inhibited only by colistin. Finally, 90% of Acinetobacter spp. isolates were not inhibited by any antibiotic tested.

Conclusion

Fosfomycin and colistin might be promising antibiotics for the treatment of infections due to E. coli or Klebsiella spp. and P. aeruginosa, respectively, in India; however, clinical trials should first corroborate the in vitro findings. The activity of tigecycline should be evaluated, as this is commonly used as last-resort option for the treatment of multidrug-resistant Acinetobacter infections.     

Synthesis,optimization, and characterization of biogenic manganese oxide (BioMnOx) by bacterial isolates from mangrove soils with sorbents property towards different toxic metals

BioMetals - Manganese oxidizing bacteria, Bacillus mycoides and Bacillus subtilis were isolated from mangrove soils and optimized for the removal of Mn(II) with simultaneous production of biogenic...     

Preventive effect of S-allyl cysteine sulfoxide (alliin) on lysosomal hydrolases and membrane-bound ATPases in isoproterenol-induced myocardial infarction in Wistar rats

In this study, S-allyl cysteine sulfoxide (SACS) was used to evaluate its preventive effect in isoproterenol (ISO)-induced myocardial ischemia in male Wistar rats. Rats were pretreated with SACS (40 and 80 mg kg(-1)) orally for 5 weeks. After the treatment period, ISO (150 mg kg(-1)) was administered subcutaneously to rats at an interval of 24 h for 2 days. The activities of beta-D-N-acetyl-glucosaminidase, beta-galactosidase, beta-glucosidase, and acid phosphatase increased in serum and heart in ISO-induced rats. In addition, these rats showed a significant (p < 0.05) increase in the activities of beta-glucuronidase and cathepsin-D in serum and heart and a significant (p < 0.05) decrease in their activities in lysosomal fraction of the heart. The activity of Na(+)K(+)-ATPase declined, while those of Ca(2+)- and Mg(2+)-ATPases significantly (p < 0.05) elevated in the heart of ISO-induced rats. Pretreatment with SACS (40 and 80 mg kg(-1)) showed a significant (p < 0.05) effect in all the biochemical parameters studied. The effect at a dose of 80 mg kg(-1) body weight was more effective than that at 40 mg kg(-1) body weight and brought back all the biochemical parameters to near normal levels. Hereby, our study shows the membrane-stabilizing as well as antioxidant effects of SACS in ISO-induced rats.     

Design and Analysis of FBG Sensor for Explosive Detection Applications

In this paper, a simple uniform fiber Bragg grating (FBG) sensor is designed, and maximum reflection of 7.1 dB at 1.55 μm is obtained. As this FBG shows a better reflection, it deserves well for the purpose of sensing and communication predominantly as they are resistant to electromagnetic radiations, light weight, low cost, firm size, and ease of handling. The proposed FBG is used for explosive sensing applications to detect explosives like trinitrotoluene (TNT), nitroglycerin, and royal demolition explosive (RDX). The different strain and temperature wavelength shifts of the explosives also analyzed and plotted.

     

Interfacial morphology and nanomechanics of cement of the barnacle, Amphibalanus reticulatus on metallic and non-metallic substrata

The barnacle exhibits a high degree of control over its attachment onto different types of solid surface. The structure and composition of barnacle cement have been reported previously, but mostly for barnacles growing on low surface energy materials. This article focuses on the strategies used by barnacles when they attach to engineering materials such as polymethylmethacrylate (PMMA), titanium (Ti) and stainless steel 316L (SS316L). Adhesion to these substrata is compared in terms of morphological structure, thickness and functional groups of the primary cement, the molting cycle and the nanomechanical properties of the cement. Structural characterization studies using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) in conjunction with nanomechanical characterization and infrared spectroscopy (FTIR) are used to understand the differences in the adhesion of primary barnacle cement to the different substrata. The results provide new insights into understanding the mechanisms at work across the barnacle-substratum interface.