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171.
Vipin Chandra Kalia Ravi Kumar Prasun Kumar Shikha Koul 《Indian journal of microbiology》2016,56(1):46-58
The use of rrs (16S rRNA) gene is widely regarded as the “gold standard” for identifying bacteria and determining their phylogenetic relationships. Nevertheless, multiple copies of this gene in a genome is likely to give an overestimation of the bacterial diversity. In each of the 50 Streptococcus genomes (16 species, 50 strains), 4–7 copies of rrs are present. The nucleotide sequences of these rrs genes show high similarity within and among genomes, which did not allow unambiguous identification. A genome-wide search revealed the presence of 27 gene sequences common to all the Streptococcus species. Digestion of these 27 gene sequences with 10 type II restriction endonucleases (REs) showed that unique RE digestion in purH gene is sufficient for clear cut identification of 30 genomes belonging to 16 species. Additional gene-RE combinations allowed identification of another 15 strains belonging to S. pneumoniae, S. pyogenes, and S. suis. For the rest 5 strains, a combination of 2 genes was required for identifying them. The proposed strategy is likely to prove helpful in proper detection of pathogens like Streptococcus.
Electronic supplementary material
The online version of this article (doi:10.1007/s12088-015-0561-5) contains supplementary material, which is available to authorized users. 相似文献172.
Rastogi S Kumar A Mehra NK Makhijani SD Manoharan A Gangal V Kumar R 《Biosensors & bioelectronics》2003,18(1):23-29
The rapid determination of waste-water quality of waste-water treatment plants in terms of pollutional strength, i.e. biochemical oxygen demand (BOD) is difficult or even impossible using the chemical determination method. The present study reports the determination of BOD within minutes using microbial BOD sensors, as compared to the 5-day determination using the conventional method. Multiple criteria establish the basis for the development of a BOD biosensor useful for rapid and reliable BOD estimation in industrial waste-waters. Of these, preparation of a suitable novel immobilized microbial membrane used in conjunction with an apt transducer is discussed. As a result, a microbial biosensor based on a formulated, synergistic, pre-tested microbial consortium has been developed for the measurement of BOD load of various industrial waste-waters. The sensor showed maximum response in terms of current difference, when a cell concentration of 2.25 x 10(10) CFU, harvested in their log phase of growth were utilized for microbial membrane construction. The sensor showed a stability of 180 days when the prepared membranes were stored at a temperature of 4 degrees C in 50 mM phosphate buffer of pH 6.8. The reusability of the immobilized membranes was up to 200 cycles without appreciable loss of their response characteristics. A linear relationship between the current change and a glucose-glutamic acid (GAA) concentration up to 60 mg l(-1) was observed (r=0.999). The lower detection limit was 1.0 mg l(-1) BOD. The sensor response was reproducible within +/-5% of the mean in a series of ten samples having 44 mg l(-1) BOD using standard a GGA solution. When used for the BOD estimation of industrial waste-waters, a relatively good agreement was found between the two methods, i.e. 5-day BOD and that measured by the developed microbial sensor. 相似文献
173.
Sheetal Uppal Shikha Salhotra Nitika Mukhi Fatima Kamal Zaidi Manas Seal Somdatta Ghosh Dey Rajiv Bhat Suman Kundu 《The Journal of biological chemistry》2015,290(4):1979-1993
Heme proteins, which reversibly bind oxygen and display a particular fold originally identified in myoglobin (Mb), characterize the “hemoglobin (Hb) superfamily.” The long known and widely investigated Hb superfamily, however, has been enriched by the discovery and investigation of new classes and members. Truncated Hbs typify such novel classes and exhibit a distinct two-on-two α-helical fold. The truncated Hb from the freshwater cyanobacterium Synechocystis exhibits hexacoordinate heme chemistry and bears an unusual covalent bond between the nonaxial His117 and a heme porphyrin 2-vinyl atom, which remains tightly associated with the globin unlike any other. It seems to be the most stable Hb known to date, and His117 is the dominant force holding the heme. Mutations of amino acid residues in the vicinity did not influence this covalent linkage. Introduction of a nonaxial His into sperm whale Mb at the topologically equivalent position and in close proximity to vinyl group significantly increased the heme stability of this prototype globin. Reversed phase chromatography, electrospray ionization-MS, and MALDI-TOF analyses confirmed the presence of covalent linkage in Mb I107H. The Mb mutant with the engineered covalent linkage was stable to denaturants and exhibited ligand binding and auto-oxidation rates similar to the wild type protein. This indeed is a novel finding and provides a new perspective to the evolution of Hbs. The successful attempt at engineering heme stability holds promise for the production of stable Hb-based blood substitute. 相似文献
174.
Gaur Shikha; Morton Mary E.; Frick G. Peter; Goodman H. Maurice 《American journal of physiology. Cell physiology》1998,275(2):C505
Earlier studies demonstrated that deprivation of growth hormone(GH) for 3 h decreased basal and maximally stimulated cytosolic Ca2+ in rat adipocytes andsuggested that membrane Ca2+channels might be decreased. Measurement of L-typeCa2+ channels in purified plasmamembranes by immunoassay or dihydropyridine binding indicated a two- tofourfold decrease after 3 h of incubation without GH. No such decreasewas seen in unfractionated adipocyte membrane preparations. Thedecrease in plasma membrane channel content was largely accounted forby redistribution of channels to a light microsomal membrane fraction.Immunoassay of 1-,2/-, and -channelsubunits in membrane fractions indicated that the channelsredistributed as intact complexes. Addition of GH during the 1st h ofincubation prevented channel redistribution, and addition of GH after 3 h restored channel distribution to the GH-replete state of freshlyisolated adipocytes. The studies suggest that GH may regulate theabundance of Ca2+ channels in theadipocyte plasma membrane and thereby modulate sensitivity to signals,the expression of which is Ca2+dependent. 相似文献
175.
Young Kwang Chae Danai Khemasuwan Anastasios Dimou Stefan Neagu Lakshmi Chebrolu Shikha Gupta Alejandra Carpio Jongoh Kim Jeong Hyun Yun Athanasios Smyrlis Alan Friedman William Tester 《PloS one》2014,9(1)
Background
Arterial and venous thrombosis may share common pathophysiology involving the activation of platelets and inflammatory mediators. A growing body of evidence suggests prothrombotic effect of renin angiotensin system (RAS) including vascular inflammation and platelet activation. We hypothesized that the use of angiotensin converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) plays a role in protecting against venous thromboembolism (VTE) in patients atherosclerosis.Methods
We conducted a retrospective study, reviewing 1,100 consecutive patients admitted to a teaching hospital with a diagnosis of either myocardial infarction or ischemic stroke from 2005 to 2010. Patients who had been treated with anticoagulation therapy before or after the first visit were excluded. The occurrence of VTE during the follow up period, risk factors for VTE on admission, and the use of ACEIs or ARBs during the follow up period were recorded.Results
The mean age of the entire study population was 68.1 years. 52.0% of the patients were female and 76.5% were African American. 67.3% were on RAS inhibitorsThe overall incidence of VTE was 9.7% (n = 107). Among the RAS inhibitor users, the incidence of VTE events was 9.0% (54/603) for the ACEI only users, 7.1% (8/113) for the ARB only users, and 0% (0/24) for the patients taking combination of ACEI and ARB. Among patients on RAS inhibitors, 8.4% (62/740) developed a VTE, compared with 12.5% (45/360) in the nonuser group [HR (hazard ratio), 0.58; 95% CI (confidence interval), 0.39–0.84; P<0.01]. Even after controlling for factors related to VTE (smoking, history of cancer, and immobilization, hormone use) and diabetes, the use of RAS inhibitors was still associated with a significantly lower risk of developing VTE (AHR, 0.59; 95% CI, 0.40–0.88; P = 0.01).Conclusions
The use of RAS inhibitors appears to be associated with a reduction in the risk of VTE. 相似文献176.
In the present study, a series of 3-hydroxy-N-(2-(substituted phenyl)-4-oxothiazolidin-3-yl)-2-napthamide derivatives were synthesized, characterized and evaluated for theirin vitroactivity, i. e., antimicrobial, antioxidant and anti-inflammatory. The target compounds were synthesized by condensation reaction of 3-hydroxy-2-naphthoic acid hydrazide with substituted benzaldehydes which were subjected to cyclization reaction with thioglycolic acid and ZnCl2 to get target compounds. The synthesized 3-hydroxy-N-(2-(substituted phenyl)-4-oxothiazolidin-3-yl)-2-napthamide derivatives were examined for their antimicrobial activity and 3-hydroxy-N-(4-oxo-2-(3,4,5-trimethoxyphenyl)thiazolidin-3-yl)-2-naphthamide ( S20 ) exhibited the highest antimicrobial potential. The N′-(2,3-dichlorobenzylidene)-3-hydroxy-2-naphthohydrazide ( S5 ) displayed good antifungal potential against Rhizopus oryzae, whereas N′-(2,3-dichlorobenzylidene)-3-hydroxy-2-naphthohydrazide ( S20 ) showed the highest antioxidant potential and N-(2-(2,6-dichlorophenyl)-4-oxothiazolidin-3-yl)-3-hydroxy-2-naphthamide ( S16 ) displayed the highest anti-inflammatory activity. The results of molecular docking studies revealed that existence of hydrogen bonding and hydrophobic interactions with their respective proteins. In silico ADMET studies were carried out by Molinspiration, Pre-ADMET and OSIRIS property explorer to predict the pharmacokinetic behaviour of synthesized 3-hydroxy-N-(2-(substituted phenyl)-4-oxothiazolidin-3-yl)-2-napthamide derivatives. 相似文献
177.
Renu A. Kowluru Ghulam Mohammad Julia M. Santos Shikha Tewari Qing Zhong 《Journal of ocular biology, diseases, and informatics》2011,4(1-2):3-9
Mitochondrial dysfunction is considered to play an important role in the development of diabetic retinopathy. Recent evidence has also shown many similarities between diabetic retinopathy and a low grade chronic inflammatory disease. The aim of this study is to understand the interrelationship between proinflammtory mediator, IL-1β and mitochondrial dysfunction in the accelerated loss of capillary cells in the retina. Using IL-1β receptor gene knockout (IL-1R1?/?) diabetic mice, we have investigated the effect of regulation of IL-1β on mitochondrial dysfunction and mtDNA damage, and increased retinal capillary cell apoptosis and the development of retinopathy. Retinal mitochondrial dysfunction and mtDNA damage were significantly ameliorated in IL-1R1?/? mice, diabetic for ~10 months, compared to the wild-type diabetic mice. This was accompanied by protection of accelerated capillary cell apoptosis and the development of acellular capillaries, histopathology associated with diabetic retinopathy. Thus, mitochondrial damage could be one of the key events via which increased inflammation contributes to the activation of the apoptotic machinery resulting in the development of diabetic retinopathy, and the possible mechanism via which inflammation contributes to the development of diabetic retinopathy includes continuous fueling of the vicious cycle of mitochondrial damage, which could be disrupted by inhibitors of inflammatory mediators. 相似文献
178.
Harsimran Kaur Shikha Singh Yogendra S. Rathore Anupam Sharma Kentaro Furukawa Stefan Hohmann Ashish Alok K. Mondal 《The Journal of biological chemistry》2014,289(29):20245-20258
Nik1 orthologs are sensor kinases that function upstream of the high osmolarity
glycerol/p38 MAPK pathway in fungi. They contain a poly-HAMP module at their N
terminus, which plays a pivotal role in osmosensing as well as fungal death upon
exposure to fludioxonil. DhNik1p is a typical member of this class that contains five
HAMP domains and four HAMP-like linkers. We investigated the contribution of each of
the HAMP-like linker regions to the functionality of DhNik1p and found that the
HAMP4b linker was essential as its deletion resulted in the complete loss of
activity. Replacement of this linker with flexible peptide sequences did not restore
DhNik1p activity. Thus, the HAMP-like sequence and possibly structural features of
this linker region are indispensable for the kinase activity of DhNik1p. To gain
insight into the global shape of the poly-HAMP module in DhNik1p (HAMP1–5),
multi-angle laser light and small angle x-ray scattering studies were carried out.
Those data demonstrate that the maltose-binding protein-tagged HAMP1–5 protein
exist as a dimer in solution with an elongated shape of maximum linear dimension
∼365 Å. Placement of a sequence similarity based model of the
HAMP1–5 protein inside experimental data-based models showed how two chains of
HAMP1–5 are entwined on each other and the overall structure retained a
periodicity. Normal mode analysis of the structural model is consistent with the H4b
linker being a key to native-like collective motion in the protein. Overall, our
shape-function studies reveal how different elements in the HAMP1–5 structure
mediate its function. 相似文献
179.
Deepamala Maji Deepti Barnawal Aakansha Gupta Shikha King A. K. Singh A. Kalra 《World journal of microbiology & biotechnology》2013,29(5):833-839
Experiments were conducted to evaluate the efficacy of calliterpenone, a natural plant growth promoter from a shrub Callicarpa macrophylla Vahl., in enhancing the growth and yield promoting effects of plant growth promoting rhizobacteria (PGPRs), in menthol mint (Mentha arvensis L).This study is based on our previous results indicating the microbial growth promotion by calliterpenone and assumption that application of calliterpenone along with PGPRs will improve the population of PGPRs resulting in higher impacts on plant growth and yield. Of the 15 PGPRs (identified as potent ones in our laboratory), 25 μl of 0.01 mM calliterpenone (8.0 μg/100 ml) was found to be useful in improving the population of nine PGPRs in culture media. The five selected strains of PGPRs exhibiting synergy with calliterpenone in enhancing growth of maize compared to PGPR or calliterpenone alone were selected and tested on two cultivars (cvs. Kosi and Kushal) of M. arvensis. Of the five strains, Bacillus subtilis P-20 (16S rDNA sequence homologous to Accession No NR027552) and B. subtilis Daz-26 (16SrDNA sequence homologuos to Accession No GU998816) were found to be highly effective in improving the herb and essential oil yield in the cultivars Kushal and Kosi respectively when co-treated with calliterpenone. The results open up the possibilities of using a natural growth promoter along with PGPRs as a bio-agri input for sustainable and organic agriculture. 相似文献
180.
Arbuscular mycorrhizal (AM) fungi exist widely in natural ecosystems as well as in salt-affected soils and are considered
suitable candidates for bio-amelioration of saline soils. Plants respond to salinity by accumulating sugars and other low-molecular-weight
compatible solutes. One such compound is trehalose, which has been found to play an important role as a stress protectant.
The aim of the present investigation was to study interactions between an AM fungus and salinity stress on growth, nitrogen
fixation, and trehalose metabolism in Cajanus cajan (L.) Millsp. (pigeonpea). Two genotypes [Sel 85N (salt-tolerant) and ICP 13997 (salt-sensitive)] were subjected to saline
treatments with and without mycorrhizal inoculations. Salinity reduced plant biomass (shoot and root) in both genotypes and
resulted in a decline in shoot-to-root ratio (SRR); however, a smaller decline was observed in Sel 85N than in ICP 13997.
AM colonization was reduced with increasing salinity levels but mycorrhizal responsiveness (MR) increased. Genotypic variability
in nitrogen fixation and trehalose metabolism in response to salinity and mycorrhization was observed. An increment in nodule
number was accompanied by a reduction in dry mass. Subsequently, nodular activity (leghemoglobin, acetylene-reduction activity
[ARA], nitrogen content) was reduced under soil salinity, which was more profound in ICP 13997 than in Sel 85N. The symbiotic
association with Glomus mosseae led to significant improvement in plant dry mass and nitrogen-fixing potential of nodules under salt stress. Salinity led
to an increase in trehalose-6-P synthetase (TPS) and trehalose-6-P phosphatase (TPP) activities resulting in increased trehalose
content in nodules, which was accompanied by inhibition of trehalose catabolism (trehalase activity). AM plants had lower
trehalase activity under saline and nonsaline conditions. Thus, a symbiotic relationship between plant roots and G. mosseae might have resulted in salinity tolerance in a genotype-dependent manner. 相似文献