Molekularna karakterizacija iz psa izdvojenog izolata bakterije Escherichia coli koji proizvodi prošireni spektrum beta-laktamaza i New Delhi metalo-beta-laktamazu-1 (blaNDM1) - prikaz slučaja

In this article, we report the molecular characterization of extensively drug resistant (XDR), extended spectrum, class C beta-lactamases and NDM-1 carbapenemase producing E. coli, isolated from the scrotal fluid of a 3-year-old male dog. In an antibiotic susceptibility test the E. coli isolate was susceptible only to tigecycline and resistant to all clinically applicable antibiotics tested in the study. The minimum inhibitory concentration (MIC) of meropenem, cefotaxime and cefepime was 256, 128 and 64 µg/mL, respectively. On genotypic screening by PCR, the isolate was positive for blaNDM, blaCTX-M, blaAmpC, blaTEM and sul1 genes. The isolate was a ESBL, AmpC and metalo beta-lactamase producer. On molecular pathotyping, the isolate harbored the Shiga toxin producing gene (Stx2). The extensively drug resistant, carbapenem resistant and ESBL producing E. coli constitutes a major public health concern, since there is a great chance of dissemination of resistance genes to humans due to the close association of humans and companion animals. To the best of our knowledge, this is the first report of blaNDM1 isolated from a dog in India.U radu se izvješćuje o molekularnoj karakterizaciji bakterije E. coli izdvojene iz skrotalne tekućine psa, iznimno otporne na antibiotike širokog spektra, koja proizvodi klasu C beta-laktamaza i NDM-1 karbapenemazu. Pas je bio u dobi od od tri godine. Izolat E. coli bio je osjetljiv samo na tigeciklin, a otporan na sve antibiotike primjenjivane u kliničkoj praksi. Minimalna inhibicijska koncentracija (MIC) za meropenem iznosila je 256, cefotaksim 128 i cefepim 64 µg/mL. Pretragom genotipa lančanom reakcijom polimerazom izolat je bio pozitivan na gene blaNDM, blaCTX-M, blaAmpC, blaTEM i sul1. Proizvodio je ESBL, AmpC i metalo-beta-laktamazu. Molekularnom patotipizacijom dokazano je da posjeduje gen za shiga-toksin (Stx2). E. coli otporna na karbapenem, koja proizvodi beta-laktamaze širokog spektra, velika je prijetnja za javno zdravstvo s obzirom na to da postoji velika mogućnost prijenosa E. coli s genom za rezistenciju na ljude u bliskom dodiru s kućnim ljubimcima. Ovo je prvo izvješće o blaNDM1 dokazanom u psa u Indiji

Sirtuin 6 inhibition protects against glucocorticoid-induced skeletal muscle atrophy by regulating IGF/PI3K/AKT signaling

Chronic activation of stress hormones such as glucocorticoids leads to skeletal muscle wasting in mammals. However, the molecular events that mediate glucocorticoid-induced muscle wasting are not well understood. Here, we show that SIRT6, a chromatin-associated deacetylase indirectly regulates glucocorticoid-induced muscle wasting by modulating IGF/PI3K/AKT signaling. Our results show that SIRT6 levels are increased during glucocorticoid-induced reduction of myotube size and during skeletal muscle atrophy in mice. Notably, overexpression of SIRT6 spontaneously decreases the size of primary myotubes in a cell-autonomous manner. On the other hand, SIRT6 depletion increases the diameter of myotubes and protects them against glucocorticoid-induced reduction in myotube size, which is associated with enhanced protein synthesis and repression of atrogenes. In line with this, we find that muscle-specific SIRT6 deficient mice are resistant to glucocorticoid-induced muscle wasting. Mechanistically, we find that SIRT6 deficiency hyperactivates IGF/PI3K/AKT signaling through c-Jun transcription factor-mediated increase in IGF2 expression. The increased activation, in turn, leads to nuclear exclusion and transcriptional repression of the FoxO transcription factor, a key activator of muscle atrophy. Further, we find that pharmacological inhibition of SIRT6 protects against glucocorticoid-induced muscle wasting in mice by regulating IGF/PI3K/AKT signaling implicating the role of SIRT6 in glucocorticoid-induced muscle atrophy.Fil: Mishra, Sneha. No especifíca;Fil: Cosentino, Claudia. Harvard Medical School; Estados UnidosFil: Tamta, Ankit Kumar. No especifíca;Fil: Khan, Danish. No especifíca;Fil: Srinivasan, Shalini. No especifíca;Fil: Ravi, Venkatraman. No especifíca;Fil: Abbotto, Elena. Università degli Studi di Genova; ItaliaFil: Arathi, Bangalore Prabhashankar. No especifíca;Fil: Kumar, Shweta. No especifíca;Fil: Jain, Aditi. No especifíca;Fil: Ramaian, Anand S.. No especifíca;Fil: Kizkekra, Shruti M.. No especifíca;Fil: Rajagopal, Raksha. No especifíca;Fil: Rao, Swathi. No especifíca;Fil: Krishna, Swati. No especifíca;Fil: Asirvatham Jeyaraj, Ninitha. Indian Institute of Technology; IndiaFil: Haggerty, Elizabeth R.. Harvard Medical School; Estados UnidosFil: Silberman, Dafne Magalí. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Kurland, Irwin J.. No especifíca;Fil: Veeranna, Ravindra P.. No especifíca;Fil: Jayavelu, Tamilselvan. No especifíca;Fil: Bruzzone, Santina. Università degli Studi di Genova; ItaliaFil: Mostoslavsky, Raul. Harvard Medical School; Estados UnidosFil: Sundaresan, Nagalingam R.. No especifíca

An ab initio and AIM investigation into the hydration of 2-thioxanthine

<p>Abstract</p> <p>Background</p> <p>Hydration is a universal phenomenon in nature. The interactions between biomolecules and water of hydration play a pivotal role in molecular biology. 2-Thioxanthine (2TX), a thio-modified nucleic acid base, is of significant interest as a DNA inhibitor yet its interactions with hydration water have not been investigated either computationally or experimentally. Here in, we reported an <it>ab initio </it>study of the hydration of 2TX, revealing water can form seven hydrated complexes.</p> <p>Results</p> <p>Hydrogen-bond (H-bond) interactions in 1:1 complexes of 2TX with water are studied at the MP2/6-311G(d, p) and B3LYP/6-311G(d, p) levels. Seven 2TX^...H₂O hydrogen bonded complexes have been theoretically identified and reported for the first time. The proton affinities (PAs) of the O, S, and N atoms and deprotonantion enthalpies (DPEs) of different N-H bonds in 2TX are calculated, factors surrounding why the seven complexes have different hydrogen bond energies are discussed. The theoretical infrared and NMR spectra of hydrated 2TX complexes are reported to probe the characteristics of the proposed H-bonds. An improper blue-shifting H-bond with a shortened C-H bond was found in one case. NBO and AIM analysis were carried out to explain the formation of improper blue-shifting H-bonds, and the H-bonding characteristics are discussed.</p> <p>Conclusion</p> <p>2TX can interact with water by five different H-bonding regimes, N-H^...O, O-H^...N, O-H^...O, O-H^...S and C-H^...O, all of which are medium strength hydrogen bonds. The most stable H-bond complex has a closed structure with two hydrogen bonds (N(7)-H^...O and O-H^...O), whereas the least stable one has an open structure with one H-bond. The interaction energies of the studied complexes are correlated to the PA and DPE involved in H-bond formation. After formation of H-bonds, the calculated IR and NMR spectra of the 2TX-water complexes change greatly, which serves to identify the hydration of 2TX.</p

Effect of plant growth regulators (PGRs) on micropropagation of a vulnerable and high value medicinal plant Hedychium spicatum

A complete micropropagation protocol was developed by applying different plant growth regulators (PGRs) of a vulnerable and high value aromatic medicinal plant, Hedychium spicatum. Three cytokinins, 6-benzyladenine (BA), kinetin (KN) and thidiazuron (TDZ) were used and among these, the lower concentration of TDZ (1.0 μM) was found to be the most effective treatment in relation to induction of high frequency shoot multiplication (83.33%), number of shoots per explant (3.86 shoots) and average number of shoots per flask (19.33 shoots). Indole-3-acetic acid (IAA), indole-3-butyric acid (IBA) and α- naphthalene acetic acid (NAA) were the used auxins in this study for in-vitro rooting. Among these used auxins, the lower concentration of IBA (2.5 μM) was the prominent plant growth regulator regarding in vitro rooting. Well rooted and healthy plantlets were obtained after 2 months of hardening and transferred to the field (1990 m) with 90.0% survival. On the basis of available literature, this is the first and significant study regarding the comparative effect of different PGRs on in-vitro propagation study of H. spicatum. This significant study could be useful for large scale propagation and ex-situ conservation of this vulnerable Himalayan species.Key words: Cytokinins, thidiazuron, shoot multiplication, in-vitro propagation, ex-situ conservation

Studies on <i style="">in vitro</i> propagation of Himalayan cedar (<i style="">Cedrus deodara</i>) using zygotic embryos and stem segments

209-215Adventitious bud formation was examined in zygotic embryos (decoated seeds) of Cedrus deodara, planted in the normal position, using four different media variously supplemented with or without plant growth regulators (PGRs). Following incubation for 7, 14, 21 and 28 days on PGR containing media, the embryos were transferred to respective PGR-free basal media. While embryo swelling was observed in all cases, normal germination was observed only in embryos cultured initially in PGR-free media. Best response, in terms of bud formation (93%), was observed in embryos first cultured on LP medium containing BA and Kinetin (1.0 M each) for 28 days and then transferred to LP medium without any PGR. While the mean number of shoots formed per cultured embryo was also highest (34%) in this combination, these shoots eventually dried when excised and sub-cultured for further multiplication. Success was, however, obtained when the embryos were initially planted in an inverted position on LP medium containing 20.0 M BA for 10 days, and then shifted, again in the inverted position, on the same medium without BA. Although the mean number of shoots formed was low (only 2.5 shoots per embryo), these could be multiplied and elongated. The microshoots (2.0-3.0 cm) thus obtained could be rooted (100%) using ½ strength, PGR-free, LP medium, hardened and established in pots. Besides excised embryos, stem segments were also used as explants. While only a quarter of explants could be established in culture, in contamination-free condition, good sprouting response (3-4 buds per segment) was obtained in certain PGR combinations. The sprouted buds developed into shoots on LP medium containing 5.0 M BA; further subculturing of excised shoots for multiplication, however, resulted in drying up of shoots. Further work is required to overcome this difficulty