Status and distribution of anthropogenic pressure in the buffer zone of Nanda Devi Biosphere Reserve in western Himalaya, India

Nanda Devi Biosphere Reserve (NDBR) (2236.74 km²), extending over three civil districts viz, Chamoli, Pithoragarh and Almora of the state of Uttar Pradesh, is an important protected area of the western Himalaya owing to its rich biological and cultural diversity. The human (n = 1856) and livestock population (n = 7785) of 19 settlements in the buffer zone as well as seasonal grazing by 15 000–20 000 migratory sheep and goats were the major sources of anthropogenic pressure in the reserve. The intensity of wood-cutting and lopping of a total of 35 sampled woody species was assessed in the buffer zone as parameters of anthropogenic pressure. Anthropogenic pressure showed restricted distribution due to the sparse location of human settlements and seasonal use of biomass resources by majority of the inhabitants, who live a trans-humane lifestyle. Intensive wood-cutting was limited to within 2 km radius of human settlements while tree lopping was mainly done by the migratory shepherds around timber-line (3600–3800 m). Of the total cut trees, the proportion of 20–60 cm girth class cut trees was recorded more. The regeneration percentage of tree species was higher in Chamoli and Pithoragarh sectors as compared to the Almora sector of the buffer zone. Fuelwood plantation in the degraded lands around villages through peoples participation, introduction of alternate fuel devices and employment opportunities have been suggested to minimize the dependence of local people on biomass resources and ensure the biodiversity conservation in the NDBR.     

Identification of a Live Attenuated Vaccine Candidate for Tularemia Prophylaxis

Francisella tularensis is the causative agent of a fatal human disease, tularemia. F. tularensis was used in bioweapon programs in the past and is now classified as a category A select agent owing to its possible use in bioterror attacks. Despite over a century since its discovery, an effective vaccine is yet to be developed. In this study four transposon insertion mutants of F. tularensis live vaccine strain (LVS) in Na/H antiporter (FTL_0304), aromatic amino acid transporter (FTL_0291), outer membrane protein A (OmpA)-like family protein (FTL_0325) and a conserved hypothetical membrane protein gene (FTL_0057) were evaluated for their attenuation and protective efficacy against F. tularensis SchuS4 strain. All four mutants were 100–1000 fold attenuated for virulence in mice than parental F. tularensis. Except for the FTL_0304, single intranasal immunization with the other three mutants provided 100% protection in BALB/c mice against intranasal challenge with virulent F. tularensis SchuS4. Differences in the protective ability of the FTL_0325 and FTL_0304 mutant which failed to provide protection against SchuS4 were investigated further. The results indicated that an early pro-inflammatory response and persistence in host tissues established a protective immunity against F. tularensis SchuS4 in the FTL_0325 immunized mice. No differences were observed in the levels of serum IgG antibodies amongst the two vaccinated groups. Recall response studies demonstrated that splenocytes from the FTL_0325 mutant immunized mice induced significantly higher levels of IFN-γ and IL-17 cytokines than the FTL_0304 immunized counterparts indicating development of an effective memory response. Collectively, this study demonstrates that persistence of the vaccine strain together with its ability to induce an early pro-inflammatory innate immune response and strong memory responses can discriminate between successful and failed vaccinations against tularemia. This study describes a live attenuated vaccine which may prove to be an ideal vaccine candidate for prevention of respiratory tularemia.     

Primary Cilium-Mediated Retinal Pigment Epithelium Maturation Is Disrupted in Ciliopathy Patient Cells

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A Method for Selection and Characterization of Rhizosphere-Competent Bacteria of Chickpea

A greenhouse assay was developed to evaluate the root-colonizing capability of the native chickpea rhizospheric bacterial population. In this assay system, screening time was reduced on two counts. First, spontaneous chromosomal rifampicin-resistant (Rif^r) strains were directly inoculated to seeds without any check for the stability of the mutation, and second, no attempts were made to taxonomically identify all the strains being screened for chickpea rhizosphere competence. Only two chickpea rhizosphere-competent Rif^r strains from the group of six good chickpea rhizosphere colonizers forming 10⁷ to 10⁸ colony-forming units (cfu)/g root were taxonomically identified as Pseudomonas fluorescens NB13R and Pseudomonas spp. NB49R, after screening 49 bacteria. Both the strains showed no difference from their corresponding wild-type strains P. fluorescens NB13 and Pseudomonas spp. NB49 in terms of chickpea rhizosphere competence. Isogenic or equally rhizospheric competitive second non-isogenic bacterial isolate, when present in tenfold higher amount, pre-empted the colonization of the soil by the bacterium, which was present in smaller ratio. These findings indicate that the isogenic or equally rhizospheric competitive second non-isogenic Rif^r strains should be compared for their survival and competition with that of the isogenic parent and with each other for specific ecological niche, before using a mixture of isolates, for stable and consistent biological seed treatment to control soilborn pathogens or pests or to promote plant growth. Received: 31 May 1996 / Accepted: 5 July 1996     

Occurrence of Salt, pH, and Temperature-tolerant, Phosphate-solubilizing Bacteria in Alkaline Soils

An ecological survey was conducted to characterize 4800 bacterial strains isolated from the root-free soil, rhizosphere, and rhizoplane of Prosopis juliflora growing in alkaline soils. Of the 4800 bacteria, 857 strains were able to solubilize phosphate on plates. The incidence of phosphate-solubilizing bacteria (PSB) in the rhizoplane was highest, followed by rhizosphere and root-free soil. Eighteen bacterial strains out of 857 PSB were able to produce halo at 30°C in a plate assay in the presence of 5% salt (NaCl) and solubilize tricalcium phosphate in National Botanical Research Institute's phosphate growth medium (NBRIP) broth, in the presence of various salts, pHs, and temperatures. Among the various bacteria tested, NBRI4 and NBRI7 did not produced halo in a plate assay at 30°C in the absence of salt. Contrary to indirect measurement of phosphate solubilization by plate assay, the direct measurement of phosphate solubilization in NBRIP broth assay always resulted in reliable results. The phosphate solubilization ability of NBRI4 was higher than in the control in the presence of salts (NaCl, CaCl₂, and KCl) at 30°C. Phosphate solubilization further increased in the presence of salts at 37°C as compared with 30°C. At 37°C, CaCl₂ reduced phosphate solubilization ability of NBRI4 compared with the control. The results indicated the role of calcium salt in the phosphate solubilization ability of NBRI4. Received: 9 March 1999 / Accepted: 16 April 1999     

TiD: Standalone software for mining putative drug targets from bacterial proteome

TiD is a standalone application, which relies on basic assumption that a protein must be essential for pathogens survival and non-homologous with host to qualify as putative target. With an input bacterial proteome, TiD removes paralogous proteins, picks essential ones, and excludes proteins homologous with host organisms. The targets illustrate non-homology with at least 40 out of 84 gut microbes, considered safe for human. TiD classifies proposed targets as known, novel and virulent. Users can perform pathway analysis, choke point analysis, interactome analysis, subcellular localization and functional annotations through web servers cross-referenced with the application. Drug targets identified by TiD for Listeria monocytogenes, Bacillus anthracis and Pseudomonas aeruginosa have revealed significant overlaps with previous studies. TiD takes < 2 h to scan putative targets from a bacterial proteome with ~ 5000 proteins; hence, we propose it as a useful tool for rational drug design. TiD is available at http://bmicnip.in/TiD/.