Antimicrobial potential and taxonomic investigation of piezotolerant <Emphasis Type="Italic">Streptomyces</Emphasis> sp. NIOT-Ch-40 isolated from deep-sea sediment

Microbial-derived natural products from extreme niches such as deepsea are known to possess structural and functional novelty. With this background, the present study was designed to investigate the bioprospecting potential and systematics of a deep-sea derived piezotolerant bacterial strain NIOT-Ch-40, showing affiliation to the genus Streptomyces based on 16S RNA gene similarity. Preliminary screening for the presence of biosynthetic genes like polyketide synthase I, polyketide synthase II, non ribosomal peptide synthase, 3-amino-5-hydroxybenzoic acid synthase and spiroindimicin followed by antibacterial activity testing confirmed the presence of potent bioactivity. The secondary metabolites produced during fermentation in Streptomyces broth at 28?°C for 7 days were extracted with ethyl acetate. The extract exhibited a specific inhibitory activity against Gram-positive bacteria and was significantly effective (p?<?0.0001) against methicillin-resistant Staphylococcus aureus (MRSA). The minimum inhibitory concentration and minimum bactericidal concentration against MRSA was 1.5 µg/mL, which was statistically significant in comparison with erythromycin. A multifaceted analysis of the Streptomyces spp. was carried out to delineate the strain NIOT-Ch-40 at a higher resolution which includes morphological, biochemical and molecular studies. Piezotolerance studies and comparison of fatty acid profiles at high pressures revealed that it could be considered as one of the taxonomic markers, especially for the strains isolated from the deep sea environments. In conclusion, the observation of comparative studies with reference strains indicated towards the strain NIOT-Ch-40 as an indigenous marine piezotolerant Streptomyces sp. with a higher probability of obtaining novel bioactive metabolites.     

Evaluation of persistence and distribution of intra-dermally administered PKH26 labelled goat bone marrow derived mesenchymal stem cells in cutaneous wound healing model

The current study was designed to study the persistence and distribution of caprine bone marrow derived mesenchymal stem cells (cBM-MSCs) when administered intra-dermally in experimentally induced cutaneous wounds in rabbits. MSC’s from goat bone marrow were isolated and their differentiation potential towards adipogenic and osteogenic lineages were assayed in vitro. The isolated cells were phenotypically analysed using flow cytometry for the expression of MSC specific matrix receptors (CD73, CD105 and Stro-1) and absence of hematopoietic lineage markers. Further, these in vitro expanded MSCs were stained with PKH26 lipophilic cell membrane red fluorescent dye and prepared for transplantation into cutaneous wounds created on rabbits. Five, 2 cm linear full thickness skin incisions were created on either side of dorsal midline of New Zealand white rabbits (n = 4). Four wounds in each animal were implanted intra-dermally with PKH26 labelled cBM-MSCs suspended in 500 µl of Phosphate Buffer Saline (PBS). Fifth wound was injected with PBS alone and treated as negative control. The skin samples were collected from respective wounds on 3, 7, 10 and 14 days after the wound creation, and cryosections of 6 µM were made from it. Fluorescent microscopy of these cryosections showed that the PKH26 labelled transplanted cells and their daughter cells demonstrated a diffuse pattern of distribution initially and were later concentrated towards the wound edges and finally appeared to be engrafted with the newly developed skin tissues. The labelled cells were found retained in the wound bed throughout the period of 14 days of experimental study with a gradual decline in their intensity of red fluorescence probably due to the dye dilution as a result of multiple cell division. The retention of transplanted MSCs within the wound bed even after the complete wound healing suggests that in addition to their paracrine actions as already been reported, they may have direct involvement in various stages of intricate wound healing process which needs to be explored further.     

Rural-urban differences on the rates and factors associated with early initiation of breastfeeding in Nigeria: further analysis of the Nigeria demographic and health survey, 2013

Background

This study investigates and compares the rates and factors associated with early initiation of breastfeeding (EIBF) within one hour of birth in rural and urban Nigeria.

Methods

Data from the 2013 Nigeria Demographic and Health Survey (NDHS) were analyzed. The rates of EIBF were reported using frequency tabulation. Associated factors were examined using Chi-Square test and further assessed on multivariable logistic regression analysis.

Results

The rates of EIBF were 30.8% (95% confidence interval [CI] 29.0, 32.6) and 41.9% (95% CI 39.6, 44.3) in rural and urban residences, respectively (p?<?0.001). The North-Central region had the highest EIBF rates both in rural (43.5%) and urban (63.5%) residences. Greater odds of EIBF in rural residence were significantly associated with higher birth order (Adjusted Odds Ratio [AOR] 1.29, 95% CI 1.10, 1.60), large birth size (AOR 1.33, 95% CI 1.10, 1.60), and health facility delivery (AOR 1.46, 95% CI 1.23, 1.72). Rural mothers in the rich wealth index, not working and whose husbands obtained at least a secondary school education had significantly higher odds of early initiation of breastfeeding. Regardless of residence, greater odds of EIBF were significantly associated with non-cesarean delivery (Rural AOR 3.50, 95% CI 1.84, 6.62; Urban AOR 2.48, 95% CI 1.60, 3.80) and living in North-Central (Rural AOR 1.84, 95% CI 1.34, 2.52; Urban AOR 4.40, 95% CI 3.15, 6.15) region. Also, higher odds of EIBF were significantly associated with living in North-East (Rural AOR 1.48, 95% CI 1.05, 2.08; Urban AOR 3.50, 95% CI 2.55, 4.83), South-South (Rural AOR 1.51, 95% CI 1.11, 2.10; Urban AOR 2.84, 95% CI 2.03, 3.97) and North-West (Urban residence only AOR 2.08, 95% CI 1.54, 2.80) regions.

Conclusions

Rural-urban differences in the rates and factors associated with EIBF exist in Nigeria with rural residence having significantly lower rates. Intervention efforts which address the risk factors identified in this study may contribute to improved EIBF rates. Efforts need to prioritize rural mothers generally, (particularly, those in rural North-West region) as well as mothers in urban South-West region of Nigeria.

     

Kaempferitrin inhibits GLUT4 translocation and glucose uptake in 3T3-L1 adipocytes

Insulin stimulated GLUT4 (glucose transporter 4) translocation and glucose uptake in muscles and adipocytes is important for the maintenance of blood glucose homeostasis in our body. In this paper, we report the identification of kaempferitrin (kaempferol 3,7-dirhamnoside), a glycosylated flavonoid, as a compound that inhibits insulin stimulated GLUT4 translocation and glucose uptake in 3T3-L1 adipocytes. In the absence of insulin, we observed that addition of kaempferitrin did not affect GLUT4 translocation or glucose uptake. On the other hand, kaempferitrin acted as an inhibitor of insulin-stimulated GLUT4 translocation and glucose uptake in 3T3-L1 adipocytes by inhibiting Akt activation. Molecular docking studies using a homology model of GLUT4 showed that kaempferitrin binds directly to GLUT4 at the glucose transportation channel, suggesting the possibility of a competition between kaempferitrin and glucose during the transport. Taken together, our data demonstrates that kaempferitrin inhibits GLUT4 mediated glucose uptake at least by two different mechanisms, one by interfering with the insulin signaling pathway and the other by a possible competition with glucose during the transport.     

Identification of 2chromosome region translocated onto the W chromosome by RFLP with EST-cDNA clones in the Gensei-kouken strains of the mulberry silkworm, Bombyx mori L

In silkworms, sex-limited strains are either obtained spontaneously or induced by X-rays or gamma rays. When a fragment of an autosome carrying a dominant allele of those genes responsible for certain characters is translocated onto a W chromosome, the female of the successive generations will express these phenotypic characters and sex discrimination can be facilitated. Gensei-kouken strains are sex-limited strains of silkworms developed by irradiating the pupae with gamma rays, by which a portion of the second chromosome is translocated onto the W chromosome. In these improved strains, the females are yellow-blooded and spin yellow cocoons. By using the EST-cDNA clones mapped on the Z chromosome, we identified the sex according to the polymorphic banding pattern or intensity of the signals. Furthermore, by using the clones on the second chromosome, the region of the second chromosome translocated onto the W chromosome was also defined. In both the A95 and A 96 strains selected for the present study, only the mid-portion of the second chromosome was translocated. The differences in length of the fragments translocated in these strains are discussed.     

The crystal structure of a cyanobacterial water-soluble carotenoid binding protein

Carotenoids undergo a wide range of photochemical reactions in animal, plant, and microbial systems. In photosynthetic organisms, in addition to light harvesting, they perform an essential role in protecting against light-induced damage by quenching singlet oxygen, superoxide anion radicals, or triplet-state chlorophyll. We have determined the crystal structure of a water-soluble orange carotenoid protein (OCP) isolated from the cyanobacterium Arthrospira maxima at a resolution of 2.1 A. OCP forms a homodimer with one carotenoid molecule per monomer. The carotenoid binding site is lined by a striking number of methionine residues. The structure reveals several possible ways in which the protein environment influences the spectral properties of the pigment and provides insight into how the OCP carries out its putative functions in photoprotection.     

A convenient synthesis and hepatoprotective activity of imidazo[1,2-c]pyrimido[5,4-e]pyrimidine, tetraazaacenaphthene and tetraazaphenalene from cyclic ketene aminals through tandem addition-cyclization reactions

A novel one-pot synthesis of imidazo[1,2-c]pyrimido[5,4-e]pyrimidinones (2), tetraazaacenaphthene-3,6-diones (4), tetarazaphenalene-1,7-dione (4d) is delineated from the reaction of cyclic ketene aminal (1) and alkyl or aryl isothiocyanate through tandem addition-cyclization reactions. However, reaction of ketene aminal (1a) with alkyl isothiocyanate only yielded angularly cyclized product 5 which did not react further to yield 6. The structure of 2c and 4d was ascertained by single crystal X-ray diffraction analysis which demonstrated a network of various inter- and intramolecular interactions, responsible for the stability and packing of the molecules in the crystalline state. Some of the compounds (2a--h) were screened for hepatoprotective activity but only 2a was found most effective.