The Bacillus anthracis chromosome contains four conserved, excision-proficient, putative prophages

Background  

Bacillus anthracis is considered to be a recently emerged clone within the Bacillus cereus sensu lato group. The B. anthracis genome sequence contains four putative lambdoid prophages. We undertook this study in order to understand whether the four prophages are unique to B. anthracis and whether they produce active phages.     

Recombinant monoclonal antibody recognizes a unique epitope on varicella-zoster virus immediate-early 63 protein

We previously constructed a recombinant monoclonal antibody (rec-MAb 63P4) that detects immediate-early protein IE63 encoded by varicella-zoster virus (VZV) in the cytoplasm of productively infected cells. Here, we used ORF63 truncation mutants to map the rec-MAb 63P4 binding epitope to amino acids 141 to 150 of VZV IE63, a region not shared with other widely used anti-IE63 antibodies, and found that the recombinant antibody does not bind to the simian IE63 counterpart.     

Ecology and Impacts of the Invasive Species, Lantana camara, in a Social-Ecological System in South India: Perspectives from Local Knowledge

We explored how the forest-dwelling Soliga community of South India views and explains biological invasions, and how local knowledge can inform scientific knowledge on biological invasions. We used an interview schedule with open-ended questions to solicit Soliga opinion on Lantana camara (lantana) invasion. The Soliga cited three reasons for lantana spread: its prolific fruit output and wide seed dispersal, change in fire management, and historical extraction of grass and bamboo. The Soliga believe that lantana invasion has had negative effects on the ecosystem and their livelihoods. Tabling scientific knowledge with local knowledge has improved our understanding of lantana invasion. The role of existing lantana in colonizing neighboring areas, and the response of native tree communities to lantana were common to both local and scientific sources. However, the Soliga view provides a more nuanced perspective of the lantana-fire relationship (contextually based on lantana density) with fires suppressing lantana when lantana density was low. This is contrary to views held by foresters and biologists, that fires are uniformly detrimental and promote lantana. Our study shows that examining Soliga observations has improved understanding of the invasion process and presents avenues for future lantana management.     

Novel High-Molecular-Weight,R-Type Bacteriocins of Clostridium difficile

Clostridium difficile causes one of the leading nosocomial infections in developed countries, and therapeutic choices are limited. Some strains of C. difficile produce phage tail-like particles upon induction of the SOS response. These particles have bactericidal activity against other C. difficile strains and can therefore be classified as bacteriocins, similar to the R-type pyocins of Pseudomonas aeruginosa. These R-type bacteriocin particles, which have been purified from different strains, each have a different C. difficile-killing spectrum, with no one bacteriocin killing all C. difficile isolates tested. We have identified the genetic locus of these “diffocins” (open reading frames 1359 to 1376) and have found them to be common among the species. The entire diffocin genetic locus of more than 20 kb was cloned and expressed in Bacillus subtilis, and this resulted in production of bactericidal particles. One of the interesting features of these particles is a very large structural protein of ∼200 kDa, the product of gene 1374. This large protein determines the killing spectrum of the particles and is likely the receptor-binding protein. Diffocins may provide an alternate bactericidal agent to prevent or treat infections and to decolonize individuals who are asymptomatic carriers.     

Antihyperglycemic effect of iridoid glucoside, isolated from the leaves of Vitex negundo in streptozotocin-induced diabetic rats with special reference to glycoprotein components

The aim of present study was to isolate an iridoid glucoside from the leaves of Vitex negundo and evaluates its effects on dearrangement in plasma and tissues glycoprotein components in streptozotocin-induced diabetic rats. The levels of blood glucose, plasma and tissues glycoproteins such as hexose, hexosamine, fucose and sialic acid were significantly increased whereas plasma insulin levels were significantly decreased in diabetic rats. On oral administration of iridoid glucoside at a concentration of 50 mg/kg b.w. once daily to diabetic rats for the period of 30 days, reversed the above-mentioned hyperglycemia-induced biochemical changes to near normal levels. The anti-hyperglycemic effect of iridoid glucoside was comparable with glibenclamide, a known hypoglycemic drug. Based on the results obtained from the present study, it may be concluded that iridoid glucoside possesses significant productive effect on glycoprotein metabolism in addition to its antidiabetic effect.     

Extracellular leucine-rich repeat proteins are required to organize the apical extracellular matrix and maintain epithelial junction integrity in C. elegans

Epithelial cells are linked by apicolateral junctions that are essential for tissue integrity. Epithelial cells also secrete a specialized apical extracellular matrix (ECM) that serves as a protective barrier. Some components of the apical ECM, such as mucins, can influence epithelial junction remodeling and disassembly during epithelial-to-mesenchymal transition (EMT). However, the molecular composition and biological roles of the apical ECM are not well understood. We identified a set of extracellular leucine-rich repeat only (eLRRon) proteins in C. elegans (LET-4 and EGG-6) that are expressed on the apical surfaces of epidermal cells and some tubular epithelia, including the excretory duct and pore. A previously characterized paralog, SYM-1, is also expressed in epidermal cells and secreted into the apical ECM. Related mammalian eLRRon proteins, such as decorin or LRRTM1-3, influence stromal ECM or synaptic junction organization, respectively. Mutants lacking one or more of the C. elegans epithelial eLRRon proteins show multiple defects in apical ECM organization, consistent with these proteins contributing to the embryonic sheath and cuticular ECM. Furthermore, epithelial junctions initially form in the correct locations, but then rupture at the time of cuticle secretion and remodeling of cell-matrix interactions. This work identifies epithelial eLRRon proteins as important components and organizers of the pre-cuticular and cuticular apical ECM, and adds to the small but growing body of evidence linking the apical ECM to epithelial junction stability. We propose that eLRRon-dependent apical ECM organization contributes to cell-cell adhesion and may modulate epithelial junction dynamics in both normal and disease situations.     

Dry film refractive index as an important parameter for ultra-low fouling surface coatings

Here we demonstrate that the film refractive index (RI) can be an even more important parameter than film thickness for identifying nonfouling polymer films to undiluted human blood plasma and serum. The film thickness and RI are two parameters obtained from ellipsometry. Previously, film thickness has been correlated to ultra-low fouling properties. Practically, the film RI can be used to characterize polymer density but is often overlooked. By varying the water content in the surface-initiated atom transfer radical polymerization of zwitterionic carboxybetaine, a minimum of ～1.5 RI units was necessary to achieve <5 ng/cm(2) of adsorption from undiluted human serum. A model of the film structure versus water content was also developed. These results point to an important parameter and simple approach for identifying surface coatings suitable for real-world applications involving complex media. Therefore, ultra-low fouling using a thin film is possible if it is densely packed.