The sensitivity to antibiotics of strains of group B streptococcus isolates from pregnant women in Belgrade

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Jovanović Luka

2016-01-01

Full Text Available Introduction: Group B streptococcus (GBS is a significant human pathogen. GBS colonizes the vagina and it is one of the most important causes of early neonatal sepsis and meningitis. In many countries, screening of pregnant women and intrapartal use of antibiotics are common practice. Macrolide and lincosamide resistant strains of GBS are a significant problem, because these antibiotics are the second line therapy in case of penicillin allergy. Aim: Our aim was to investigate the frequency of antibiotic resistant strains of GBS and to detect macrolide resistance phenotypes in GBS strains obtained from pregnant women in Belgrade. Material and Methods: 105 GBS isolates were obtained from vaginal swabs of pregnant women attending two Gynecology and Obstetrics Centers in Belgrade. The isolates were tested for antimicrobial susceptibility pattern and D test were performed on Mueller Hinton agar. Results: Macrolide and lincosamide resistance was found in 30.4 %, and 23.8 % of isolates, respectively. There was a high frequency of tetracycline resistant strains (88.6 %. Most frequent macrolide resistant phenotype was iMLSb (macrolide and inducibile lincosamide resistance (62.4%. Conclusion: The results of our study indicate that there is a high level of macrolide resistance among GBS isolates in Serbia and the active surveillance is needed.

Flagellin Diversity in Clostridium botulinum Groups I and II: a New Strategy for Strain Identification▿

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Paul, Catherine J.; Twine, Susan M.; Tam, Kevin J.; Mullen, James A.; Kelly, John F.; Austin, John W.; Logan, Susan M.

2007-01-01

Strains of Clostridium botulinum are traditionally identified by botulinum neurotoxin type; however, identification of an additional target for typing would improve differentiation. Isolation of flagellar filaments and analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that C. botulinum produced multiple flagellin proteins. Nano-liquid chromatography-tandem mass spectrometry (nLC-MS/MS) analysis of in-gel tryptic digests identified peptides in all flagellin bands that matched two homologous tandem flagellin genes identified in the C. botulinum Hall A genome. Designated flaA1 and flaA2, these open reading frames encode the major structural flagellins of C. botulinum. Colony PCR and sequencing of flaA1/A2 variable regions classified 80 environmental and clinical strains into group I or group II and clustered isolates into 12 flagellar types. Flagellar type was distinct from neurotoxin type, and epidemiologically related isolates clustered together. Sequencing a larger PCR product, obtained during amplification of flaA1/A2 from type E strain Bennett identified a second flagellin gene, flaB. LC-MS analysis confirmed that flaB encoded a large type E-specific flagellin protein, and the predicted molecular mass for FlaB matched that observed by SDS-PAGE. In contrast, the molecular mass of FlaA was 2 to 12 kDa larger than the mass predicted by the flaA1/A2 sequence of a given strain, suggesting that FlaA is posttranslationally modified. While identification of FlaB, and the observation by SDS-PAGE of different masses of the FlaA proteins, showed the flagellin proteins of C. botulinum to be diverse, the presence of the flaA1/A2 gene in all strains examined facilitates single locus sequence typing of C. botulinum using the flagellin variable region. PMID:17351097

Flagellin diversity in Clostridium botulinum groups I and II: a new strategy for strain identification.

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Paul, Catherine J; Twine, Susan M; Tam, Kevin J; Mullen, James A; Kelly, John F; Austin, John W; Logan, Susan M

2007-05-01

Strains of Clostridium botulinum are traditionally identified by botulinum neurotoxin type; however, identification of an additional target for typing would improve differentiation. Isolation of flagellar filaments and analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that C. botulinum produced multiple flagellin proteins. Nano-liquid chromatography-tandem mass spectrometry (nLC-MS/MS) analysis of in-gel tryptic digests identified peptides in all flagellin bands that matched two homologous tandem flagellin genes identified in the C. botulinum Hall A genome. Designated flaA1 and flaA2, these open reading frames encode the major structural flagellins of C. botulinum. Colony PCR and sequencing of flaA1/A2 variable regions classified 80 environmental and clinical strains into group I or group II and clustered isolates into 12 flagellar types. Flagellar type was distinct from neurotoxin type, and epidemiologically related isolates clustered together. Sequencing a larger PCR product, obtained during amplification of flaA1/A2 from type E strain Bennett identified a second flagellin gene, flaB. LC-MS analysis confirmed that flaB encoded a large type E-specific flagellin protein, and the predicted molecular mass for FlaB matched that observed by SDS-PAGE. In contrast, the molecular mass of FlaA was 2 to 12 kDa larger than the mass predicted by the flaA1/A2 sequence of a given strain, suggesting that FlaA is posttranslationally modified. While identification of FlaB, and the observation by SDS-PAGE of different masses of the FlaA proteins, showed the flagellin proteins of C. botulinum to be diverse, the presence of the flaA1/A2 gene in all strains examined facilitates single locus sequence typing of C. botulinum using the flagellin variable region.

Mitis group streptococci express variable pilus islet 2 pili.

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Zähner, Dorothea; Gandhi, Ashish R; Yi, Hong; Stephens, David S

2011-01-01

Streptococcus oralis, Streptococcus mitis, and Streptococcus sanguinis are members of the Mitis group of streptococci and agents of oral biofilm, dental plaque and infective endocarditis, disease processes that involve bacteria-bacteria and bacteria-host interactions. Their close relative, the human pathogen S. pneumoniae uses pilus-islet 2 (PI-2)-encoded pili to facilitate adhesion to eukaryotic cells. PI-2 pilus-encoding genetic islets were identified in S. oralis, S. mitis, and S. sanguinis, but were absent from other isolates of these species. The PI-2 islets resembled the genetic organization of the PI-2 islet of S. pneumoniae, but differed in the genes encoding the structural pilus proteins PitA and PitB. Two and three variants of pitA (a pseudogene in S. pneumoniae) and pitB, respectively, were identified that showed ≈20% difference in nucleotide as well as corresponding protein sequence. Species-independent combinations of pitA and pitB variants indicated prior intra- and interspecies horizontal gene transfer events. Polyclonal antisera developed against PitA and PitB of S. oralis type strain ATCC35037 revealed that PI-2 pili in oral streptococci were composed of PitA and PitB. Electronmicrographs showed pilus structures radiating >700 nm from the bacterial surface in the wild type strain, but not in an isogenic PI-2 deletion mutant. Anti-PitB-antiserum only reacted with pili containing the same PitB variant, whereas anti-PitA antiserum was cross-reactive with the other PitA variant. Electronic multilocus sequence analysis revealed that all PI-2-encoding oral streptococci were closely-related and cluster with non-PI-2-encoding S. oralis strains. This is the first identification of PI-2 pili in Mitis group oral streptococci. The findings provide a striking example of intra- and interspecies horizontal gene transfer. The PI-2 pilus diversity provides a possible key to link strain-specific bacterial interactions and/or tissue tropisms with pathogenic traits

Mitis group streptococci express variable pilus islet 2 pili.

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Dorothea Zähner

Full Text Available Streptococcus oralis, Streptococcus mitis, and Streptococcus sanguinis are members of the Mitis group of streptococci and agents of oral biofilm, dental plaque and infective endocarditis, disease processes that involve bacteria-bacteria and bacteria-host interactions. Their close relative, the human pathogen S. pneumoniae uses pilus-islet 2 (PI-2-encoded pili to facilitate adhesion to eukaryotic cells.PI-2 pilus-encoding genetic islets were identified in S. oralis, S. mitis, and S. sanguinis, but were absent from other isolates of these species. The PI-2 islets resembled the genetic organization of the PI-2 islet of S. pneumoniae, but differed in the genes encoding the structural pilus proteins PitA and PitB. Two and three variants of pitA (a pseudogene in S. pneumoniae and pitB, respectively, were identified that showed ≈20% difference in nucleotide as well as corresponding protein sequence. Species-independent combinations of pitA and pitB variants indicated prior intra- and interspecies horizontal gene transfer events. Polyclonal antisera developed against PitA and PitB of S. oralis type strain ATCC35037 revealed that PI-2 pili in oral streptococci were composed of PitA and PitB. Electronmicrographs showed pilus structures radiating >700 nm from the bacterial surface in the wild type strain, but not in an isogenic PI-2 deletion mutant. Anti-PitB-antiserum only reacted with pili containing the same PitB variant, whereas anti-PitA antiserum was cross-reactive with the other PitA variant. Electronic multilocus sequence analysis revealed that all PI-2-encoding oral streptococci were closely-related and cluster with non-PI-2-encoding S. oralis strains.This is the first identification of PI-2 pili in Mitis group oral streptococci. The findings provide a striking example of intra- and interspecies horizontal gene transfer. The PI-2 pilus diversity provides a possible key to link strain-specific bacterial interactions and/or tissue tropisms with

Diagnostic tools based on minor groove binder probe technology for rapid identification of vaccinal and field strains of canine parvovirus type 2b.

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Decaro, Nicola; Martella, Vito; Elia, Gabriella; Desario, Costantina; Campolo, Marco; Buonavoglia, Domenico; Bellacicco, Anna Lucia; Tempesta, Maria; Buonavoglia, Canio

2006-12-01

TaqMan-based diagnostic tests have been developed for the identification of canine parvovirus type 2 (CPV-2) strains in the faeces of dogs with diarrhoea, including a minor groove binder (MGB) probe assay for identification of type 2-based vaccines and field strains (types 2a, 2b and 2c). Since type 2b vaccines have been licensed recently in Europe, two novel MGB assays were developed for discrimination between type 2b vaccines and field strains of CPV. Such assays have been found to be highly sensitive, specific and reproducible, allowing for simultaneous detection of type 2b vaccinal and field strains present in the same specimens. These new assays will help resolution of the diagnostic problems related to the detection of a type 2b strain in the faeces of dogs shortly after the administration of a type 2b vaccine.

A novel multiplex PCR discriminates Bacillus anthracis and its genetically related strains from other Bacillus cereus group species.

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Hirohito Ogawa

Full Text Available Anthrax is an important zoonotic disease worldwide that is caused by Bacillus anthracis, a spore-forming pathogenic bacterium. A rapid and sensitive method to detect B. anthracis is important for anthrax risk management and control in animal cases to address public health issues. However, it has recently become difficult to identify B. anthracis by using previously reported molecular-based methods because of the emergence of B. cereus, which causes severe extra-intestinal infection, as well as the human pathogenic B. thuringiensis, both of which are genetically related to B. anthracis. The close genetic relation of chromosomal backgrounds has led to complexity of molecular-based diagnosis. In this study, we established a B. anthracis multiplex PCR that can screen for the presence of B. anthracis virulent plasmids and differentiate B. anthracis and its genetically related strains from other B. cereus group species. Six sets of primers targeting a chromosome of B. anthracis and B. anthracis-like strains, two virulent plasmids, pXO1 and pXO2, a bacterial gene, 16S rRNA gene, and a mammalian gene, actin-beta gene, were designed. The multiplex PCR detected approximately 3.0 CFU of B. anthracis DNA per PCR reaction and was sensitive to B. anthracis. The internal control primers also detected all bacterial and mammalian DNAs examined, indicating the practical applicability of this assay as it enables monitoring of appropriate amplification. The assay was also applied for detection of clinical strains genetically related to B. anthracis, which were B. cereus strains isolated from outbreaks of hospital infections in Japan, and field strains isolated in Zambia, and the assay differentiated B. anthracis and its genetically related strains from other B. cereus group strains. Taken together, the results indicate that the newly developed multiplex PCR is a sensitive and practical method for detecting B. anthracis.

Strain Hardening Behaviour and Its Effect on Properties of ZrB2 Reinforced Al Composite Prepared by Powder Metallurgy Technique

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Kaku, Sai Mahesh Yadav; Khanra, Asit Kumar; Davidson, M. J.

2018-04-01

Strain hardening behaviour has significant effect on altering the properties of materials. In the present study, Al-ZrB2 metal matrix composites are made through powder metallurgy route. Incremental weight percentage (wt%) of ZrB2 (0, 2, 4 and 6 wt%) are added to Aluminium matrix to produce different composites. The homogenous powder mixture is compacted and pressurelessly sintered. Sintering of composites is performed over a range of 450-575 °C. The optimized sintered condition is observed at 550 °C for 1 h in controlled atmosphere (argon gas flow). The sintered compacts are strained in incremental steps in different levels up to failure. A visible crack on the bulge of the powder preform is considered as the failure. Composites are strain hardened up to failure. To evaluate the effect of temperature on strain hardening, strain hardening is carried out at different temperatures. Composites are densified with the extent of straining and hardness increases with the increase of strain. Hardness increase with the increase in temperature is maintained during strain hardening. To evaluate the corrosion behaviour of Al-ZrB2 composite, potentiodynamic polarization study are performed on the strained composites. Corrosion rate decrease with the extent of straining.

Metabolism of dimethylphthalate by Micrococcus sp. strain 12B.

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Eaton, R W; Ribbons, D W

1982-01-01

During growth of Micrococcus sp. strain 12B with dimethylphthalate, 4-carboxy-2-hydroxymuconate lactone (CHML, X) and 3,4-dihydroxyphthalate-2-methyl ester (XI) were isolated from culture filtrates. CHML is the lactone of intermediate 4-carboxy-2-hydroxymuconate (IX). Accumulation of XI which is not a substrate for 3,4-dihydroxyphthalate-2-decarboxylase in strain 12B afforded an easy access to the preparation of 3,4-dihydroxyphthalate. PMID:7085569

Evidence for differences between B. bruxellensis strains originating from an enological environment

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Vincent Renouf

2009-03-01

Full Text Available Vincent Renouf1,2, Cécile Miot-Sertier2, Marie-Claire Perello2, Gilles de Revel2, Aline Lonvaud-Funel21Laffort, Bordeaux, France; 2UMR Œnologie, INRA-Université Bordeaux, FranceAbstract: The aim of this paper is to study and compare the physiological diversity of different strains of a wine spoilage yeast species: Brettanomyces bruxellensis. The minimum inhibitory concentrations of several drugs on different B. bruxellensis strains were scored on solid nutrient media. This revealed variations in resistance among the B. bruxellensis strains. Their capacity to develop in different wine and must environments: pH, ethanol, and SO2 concentrations, were evaluated by measuring the direct incubation survival rate. The results, compared with those obtained for other wine yeast species, confirmed the remarkable resistance of B. bruxellensis strains to various conditions which inhibit the growth of other species. Nevertheless some differences were observed among the B. bruxellensis strains, thus confirming their physiological diversity. A comparison of their volatile phenol production revealed intraspecific heterogeneity among B. bruxellensis strains. B. bruxellensis is one of the microbial species most resistant to environmental constraints in wine. It is the best adapted to growing in wine and spoiling it by volatile phenol production. However, different B. bruxellensis strains exhibit varying characteristics, particularly their capacity to produce volatile phenols. This implies that certain strains are more prejudicial than others. Further studies are required to determine the molecular causes of this intraspecific diversity.Keywords: Brettanomyces bruxellensis, strain diversity, physiology, volatile phenols

Effects of hydrostatic pressure and biaxial strains on the elastic and electronic properties of t-C8B2N2

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Zhu, Haiyan; Shi, Liwei; Li, Shuaiqi; Duan, Yifeng; Zhang, Shaobo; Xia, Wangsuo

2018-04-01

The effects of hydrostatic pressure and biaxial strains on the elastic and electronic properties of a superhard material t-C8B2N2 have been studied using first-principles calculations. The structure is proven to be mechanically and dynamically stable under the applied external forces. All the elastic constants (except C66) and elastic modulus increase (decrease) with increasing pressure and compressive (tensile) biaxial strain ɛxx. A microscopic model is used to calculate the Vicker's hardness of every single bond as well as the crystal. The hardness of t-C8B2N2 (64.7 GPa) exceeds that of c-BN (62 GPa) and increases obviously by employing pressure and compressive ɛxx. Furthermore, the Debye temperature and anisotropy of sound velocities for t-C8B2N2 have been discussed. t-C8B2N2 undergoes an indirect to direct bandgap transition when ɛxx > 2%; however, the indirect bandgap character of the material remains under pressure.

Association and Expression of Virulence from Plasmids of the Group B Strain in Pseudomonas syringae pv. eriobotryae

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Tran Dang Khanh

2018-04-01

Full Text Available Pseudomonas syringae pv. eriobotryae causes serious stem canker in loquat (Eriobotrya japonica trees. This study was conducted to determine whether plasmids are involved with its virulence. The strain NAE89, which belonged to the B group, harbored two plasmids at approximately 6.2 and 50 Mdal that caused stem canker and halo leaf spots on loquat plants. Following digestion with BamHI and ligation into the BamHI cloning site of the broad range host cosmid pLAFR3, four DNA fragments at 3.8, 6.6, 12.3, and 22.8 kb were generated. Although the plasmid-encoded virulence gene psvA was undigested with the BamHI, the halo leaf spot gene may be adjacent to the psvA gene was digested. A pLAFR3 cosmid clone was introduced into the non-pathogenic PE0 and NAE89-1 strains by triparental matings and the pathogenicity was recovered. As a result, the pLAFR3 cosmid clone was introduced into the largest size DNA fragment of 22.8 kb and determined to be the causal agent of canker on the stem of the loquat. This study revealed that the psvA gene, previously found in the 50 Mdal plasmid, was also observed in the 22.8 kb DNA fragment.

Complete genome sequence of Lactobacillus plantarum LZ95, a potential probiotic strain producing bacteriocins and B-group vitamin riboflavin.

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Li, Ping; Gu, Qing

2016-07-10

Lactobacillus plantarum LZ95 is a potential probiotic isolated from newborn infant fecal and it is identified to produce riboflavin with great antimicrobial activity. The complete genome sequence of this strain was reported in the present study. The genome contains a 3,261,418-bp chromosome and two plasmids. Genes, related to the biosynthesis of bacteriocins and riboflavin, were identified. This work will facilitate to reveal the biosynthetic mechanism of bacteriocins and B-group vitamins in lactic acid bacteria and provide evidence for its potential application in food industry. Copyright © 2016 Elsevier B.V. All rights reserved.

Pesticide lambda-cyhalothrin degradation using mesorhizobium sp. (s1b) and bartonella sp. (s2b) strains isolated from cotton crop

International Nuclear Information System (INIS)

Chumro, W.A.; Phulpoto, A.H.; Mangi, S.; Kanhar, N.A.; Ahmed, S.; Qazi, M.A.; Pirzada, T.

2017-01-01

Lambda-cyhalothrin (LC), synthetic pyrethroid pesticide is used to control a wide range of pests in variety of agricultural fields. Pesticides are potentially harmful environmental pollutants and pose serious threat to human health. Very limited options are available for environment friendly removal of LC. Interestingly, soil microbes have been known to possess remarkable genetic makeup that helps them to perform vital job in cleaning-up harmful pollutants from the environment. In present study, two LC-degrading bacteria viz. Mesorhizobium sp. strain S1B (Accession no. gb|MF471843|) and Bartonella sp. strain S2B (Accession no. b|MF471844|) were isolated by soil enrichment technique from cotton crop soil and characterized taxonomically using conventional methods and molecular PCR-based 16S rRNA sequence homology. The bacterial strains S1B and S2B achieved 29% and 40% removal of LC (conc. 250 mg/L, w/v), with maximum growth absorbance (OD) of 1.19 +- 0.06 and 1.13+- 0.09, respectively, during 20 days of incubation at 30 degree C and agitation 200 rpm under experimental laboratory circumstances. The percent removal of LC was estimated using UV-Vis Spectroscopy at 287 nm (? max) against the standard curve plotted at different LC concentrations. The bacterial isolates of present study have exhibited substantial efficiency for environmental biodegradation of the pesticide. (author)

Serological diagnosis of bovine brucellosis using B. melitensis strain B115.

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Corrente, Marialaura; Desario, Costantina; Parisi, Antonio; Grandolfo, Erika; Scaltrito, Domenico; Vesco, Gesualdo; Colao, Valeriana; Buonavoglia, Domenico

2015-12-01

Bovine brucellosis is diagnosed by official tests, such as Rose Bengal plate test (RBPT) and Complement Fixation test (CFT). Both tests detect antibodies directed against the lipolysaccharide (LPS) of Brucella cell wall. Despite their good sensitivity, those tests do not discriminate between true positive and false positive serological reactions (FPSR), the latter being generated by animals infected with other Gram negative microorganisms that share components of Brucella LPS. In this study, an antigenic extract from whole Brucella melitensis B115 strain was used to set up an ELISA assay for the serological diagnosis of bovine brucellosis. A total of 148 serum samples from five different groups of animals were tested: Group A: 28 samples from two calves experimentally infected with Yersinia enterocolitica O:9; Group B: 30 samples from bovines infected with Brucella abortus; Group C: 50 samples from brucellosis-free herds; Group D: 20 samples RBPT positive and CFT negative; Group E: 20 samples both RBPT and CFT positive. Group D and Group E serum samples were from brucellosis-free herds. Positive reactions were detected only by RBPT and CFT in calves immunized with Y. enterocolitica O:9. Sera from Group B animals tested positive also in the ELISA assay, whereas sera from the remaining groups were all negative. The results obtained encourage the use of the ELISA assay to implement the serological diagnosis of brucellosis. Copyright © 2015 Elsevier B.V. All rights reserved.

Isolation and Characterization of Plantaricin Produced by Lactobacillus plantarum Strains (IIA-1A5, IIA-1B1, IIA-2B2

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I. I. Arief

2013-08-01

Full Text Available Bacteriocins produced by Indonesian lactic acid bacteria Lactobacillus plantarum IIA-1A5, IIA-1B1, IIA-2B2 were purified and characterized. Plantaricin W gene had been successfully amplified from all strains. This amplicon showed the expected 200 bp size of plantaricin W gene. This bacteriocins purified from L. plantarum IIA-1A5, IIA-1B1, and IIA-2B2 were named plantaricin IIA-1A5, IIA-1B1, and IIA-2B2. Purification by cation exchange chromatography increased the purity (fold and activity of plantaricins. Purity of plantaricin IIA-1A5 was increased by 3.13 fold with specific activity 13.40 AU/mg. Plantaricin IIA-1B1 had 2.98 fold purity with specific activity 5.12 AU/mg, while purity of plantaricin IIA-2B2 was 1.37 fold with specific activity 7.70 AU/mg. All plantaricins could inhibit the growth of pathogenic bacteria, such as Escherichia coli, Salmonella typhimurium, Bacillus cereus, and Staphylococcus aureus. Plantaricins could be digested by trypsin. Stability of plantaricins at 80 oC for 30 min and at 121 oC for 15 min were affected by type of plantaricin and species of pathogenic bacteria. Generally, plantaricin IIA-1A5 was better as antimicrobial agent than plantaricin IIA-1B1 and plantaricin IIA-2B2.

Detection of Enterohemorrhagic Escherichia coli Related Genes in E. coli Strains Belonging to B2 Phylogroup Isolated from Urinary Tract Infections in Combination with Antimicrobial Resistance Phenotypes

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Hamid Staji

2017-07-01

Full Text Available Background:  This study was conducted to detect the prevalence of EHEC virulence genes and antimicrobial resistance profile of Escherichia coli strains belonging to B2 phylogroup implicated in Urinary tract infections in Semnan, Iran.Methods:   From 240 urine samples 160 E. coli strains were isolated, biochemically. Then, E. coli isolates were examined by Multiplex-PCR for phylogenetic typing and detection of virulence genes (hly, stx1, stx2, eae associated with Enterohemorrhagic E. coli. Finally, Antimicrobial resistance of E. coli isolates were characterized using Disk Diffusion method.  Results:  From 160 E. coli isolates, 75 strains (47% were assigned to B2 phylogenetic group and prevalence of virulence genes were as follow: hly (21.3%, stx1 (16%, stx2 (10.6% and eae (6.7%, subsequently.  Phenotypic antimicrobial resistance of B2 isolates showed that all isolates were sensitive to Meropenem and Furazolidone and then highest frequency of resistance was observed to Streptomycin, Oxytetracycline, Neomycin, Nalidixic acid and Ampicillin (98.7% to 49.3%. Also low resistance prevalence was observed in case of Ceftizoxime, Lincospectin, Imipenem, Chloramphenicol and flurefenicole (16% to 1.3%.Conclusion:   The data suggest a high prevalence of antibiotic resistance in UPEC strains belonging to B2 phylogroup even for the antimicrobials using in pet and farm animals and their potential to cause EHEC specific clinical symptoms which may represent a serious health risk since these strains can be transmitted to GI tract and act as a reservoir for other uropathogenic E. coli and commensal strains.

Bacillus amyloliquefaciens, Bacillus velezensis, and Bacillus siamensis Form an "Operational Group B. amyloliquefaciens" within the B. subtilis Species Complex.

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Fan, Ben; Blom, Jochen; Klenk, Hans-Peter; Borriss, Rainer

2017-01-01

The plant growth promoting model bacterium FZB42 T was proposed as the type strain of Bacillus amyloliquefaciens subsp. plantarum (Borriss et al., 2011), but has been recently recognized as being synonymous to Bacillus velezensis due to phylogenomic analysis (Dunlap C. et al., 2016). However, until now, majority of publications consider plant-associated close relatives of FZB42 still as " B. amyloliquefaciens ." Here, we reinvestigated the taxonomic status of FZB42 and related strains in its context to the free-living soil bacterium DSM7 T , the type strain of B. amyloliquefaciens . We identified 66 bacterial genomes from the NCBI data bank with high similarity to DSM7 T . Dendrograms based on complete rpoB nucleotide sequences and on core genome sequences, respectively, clustered into a clade consisting of three tightly linked branches: (1) B. amyloliquefaciens , (2) Bacillus siamensis , and (3) a conspecific group containing the type strains of B. velezensis, Bacillus methylotrophicus , and B. amyloliquefaciens subsp. plantarum . The three monophyletic clades shared a common mutation rate of 0.01 substitutions per nucleotide position, but were distantly related to Bacillus subtilis (0.1 substitutions per nucleotide position). The tight relatedness of the three clusters was corroborated by TETRA, dDDH, ANI, and AAI analysis of the core genomes, but dDDH and ANI values were found slightly below species level thresholds when B. amyloliquefaciens DSM7 T genome sequence was used as query sequence. Due to these results, we propose that the B. amyloliquefaciens clade should be considered as a taxonomic unit above of species level, designated here as "operational group B. amyloliquefaciens " consisting of the soil borne B. amyloliquefaciens , and plant associated B. siamensis and B. velezensis , whose members are closely related and allow identifying changes on the genomic level due to developing the plant-associated life-style.

MODERNIZATION OF GENEOTIPING OF STRAINS B. PERTUSSIS

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G. A. Ivashinnikova

2013-01-01

Full Text Available The new rapid molecular genotyping method was developed for studying the structure of ptxP promoter of pertussis toxin. Method is based on PCR-RFLP analysis, which allows studying the specific restriction profiles of the B. pertussis strains and allows differentiation of the strains with the ptxP structural particularities. The developed method for genotyping of strains of B. pertussis can be hhelpful when monitoring strains of the causative agent of whooping cough in system of an epidemiological surveillance over pertussis infections, allowing observation over circulating population of B.pertussis, revealing strains of the causative agent of whooping cough with high production of pertussis toxin and to watch their distribution.

Bacillus amyloliquefaciens, Bacillus velezensis, and Bacillus siamensis Form an “Operational Group B. amyloliquefaciens” within the B. subtilis Species Complex

Science.gov (United States)

Fan, Ben; Blom, Jochen; Klenk, Hans-Peter; Borriss, Rainer

2017-01-01

The plant growth promoting model bacterium FZB42T was proposed as the type strain of Bacillus amyloliquefaciens subsp. plantarum (Borriss et al., 2011), but has been recently recognized as being synonymous to Bacillus velezensis due to phylogenomic analysis (Dunlap C. et al., 2016). However, until now, majority of publications consider plant-associated close relatives of FZB42 still as “B. amyloliquefaciens.” Here, we reinvestigated the taxonomic status of FZB42 and related strains in its context to the free-living soil bacterium DSM7T, the type strain of B. amyloliquefaciens. We identified 66 bacterial genomes from the NCBI data bank with high similarity to DSM7T. Dendrograms based on complete rpoB nucleotide sequences and on core genome sequences, respectively, clustered into a clade consisting of three tightly linked branches: (1) B. amyloliquefaciens, (2) Bacillus siamensis, and (3) a conspecific group containing the type strains of B. velezensis, Bacillus methylotrophicus, and B. amyloliquefaciens subsp. plantarum. The three monophyletic clades shared a common mutation rate of 0.01 substitutions per nucleotide position, but were distantly related to Bacillus subtilis (0.1 substitutions per nucleotide position). The tight relatedness of the three clusters was corroborated by TETRA, dDDH, ANI, and AAI analysis of the core genomes, but dDDH and ANI values were found slightly below species level thresholds when B. amyloliquefaciens DSM7T genome sequence was used as query sequence. Due to these results, we propose that the B. amyloliquefaciens clade should be considered as a taxonomic unit above of species level, designated here as “operational group B. amyloliquefaciens” consisting of the soil borne B. amyloliquefaciens, and plant associated B. siamensis and B. velezensis, whose members are closely related and allow identifying changes on the genomic level due to developing the plant-associated life-style. PMID:28163698

[The characteristics of epidemic influenza A and B virus strains circulating in Russia during the 2007-2008 season].

Science.gov (United States)

Ivanova, V T; Trushakova, S V; Oskerko, T A; Shevchenko, E S; Kolobukhina, L V; Vartanian, R V; Beliakova, N V; Iatsyshina, S B; Feodoritova, E L; Zueva, N D; Burtseva, E I

2009-01-01

In 2007-2008 in Russia, the epidemic upsurge of influenza morbidity was caused by the active circulation of influenza A(H1N1, A(H3N2), and B viruses. The center for Ecology and Epidemiology of Influenza studied 334 epidemic strains. The results of a comparative study of the svirus specificity of commercial test systems (AmpliSens Influenza virus A/B and AmpliSens Influenza virus A/H5N1) for the polymerase chain reaction diagnosis and virological assays, including virus isolation, revealed their high correlation, which confirms that they may be expensively used to monitor the circulation of influenza viruses in the Russian Federation. All the strains were isolated in the MDCK cell culture. Influenza A(H1N1) viruses (n = 127) were antigenic variants of the reference strains A/Solomon Islands/3/06 and A/Brisbane/59107. Influenza A(H3N2) viruses (n = 49) were antigenic variants of the reference strains A/Wisconsin/67/05 and A/Brisbane/10/08. One hundred and fifty seven Influenza B strains were drift variants of the reference strains B/Florida/4/06 and B/Shanghai/361/02 of lineage B/Yamagata/16/88 and one strain, a variant of Malaysia/2506/04 related to lineage B/victoria/2/87. The isolates interacted actively with human 0(I) blood group erythrocytes and much more weakly with chicken ones. All study influenza A(H1N1) viruses (n = 74) preserved their sensitivity to rimantadine while 24 (77%) of the 31 study influenza A(H3N2) virus strains were resistant. A study of the time course of changes in the generation of antibodies in the donor sera obtained in Moscow and the Moscow Region in different periods of the epidemic process revealed an increase in antibodies to the reference influenza A and B virus strains circulating in this period.

Bactericidal antibody against a representative epidemiological meningococcal serogroup B panel confirms that MATS underestimates 4CMenB vaccine strain coverage.

Science.gov (United States)

Frosi, Giacomo; Biolchi, Alessia; Lo Sapio, Morena; Rigat, Fabio; Gilchrist, Stefanie; Lucidarme, Jay; Findlow, Jamie; Borrow, Ray; Pizza, Mariagrazia; Giuliani, Marzia Monica; Medini, Duccio

2013-10-09

4CMenB (Bexsero), a vaccine developed against invasive meningococcal disease caused by capsular group B strains (MenB), was recently licensed for use by the European Medicines Agency. Assessment of 4CMenB strain coverage in specific epidemiologic settings is of primary importance to predict vaccination impact on the burden of disease. The Meningococcal Antigen Typing System (MATS) was developed to predict 4CMenB strain coverage, using serum bactericidal antibody assay with human complement (hSBA) data from a diverse panel of strains not representative of any specific epidemiology. To experimentally validate the accuracy of MATS-based predictions against strains representative of a specific epidemiologic setting. We used a stratified sampling method to identify a representative sample from all MenB disease isolates collected from England and Wales in 2007-2008, tested the strains in the hSBA assay with pooled sera from infant and adolescent vaccinees, and compared these results with MATS. MATS predictions and hSBA results were significantly associated (P=0.022). MATS predicted coverage of 70% (95% CI, 55-85%) was largely confirmed by 88% killing in the hSBA (95% CI, 72-95%). MATS had 78% accuracy and 96% positive predictive value against hSBA. MATS is a conservative predictor of strain coverage by the 4CMenB vaccine in infants and adolescents. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Comparative transcriptional profiling of Bacillus cereus sensu lato strains during growth in CO2-bicarbonate and aerobic atmospheres.

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Karla D Passalacqua

Full Text Available Bacillus species are spore-forming bacteria that are ubiquitous in the environment and display a range of virulent and avirulent phenotypes. This range is particularly evident in the Bacillus cereus sensu lato group; where closely related strains cause anthrax, food-borne illnesses, and pneumonia, but can also be non-pathogenic. Although much of this phenotypic range can be attributed to the presence or absence of a few key virulence factors, there are other virulence-associated loci that are conserved throughout the B. cereus group, and we hypothesized that these genes may be regulated differently in pathogenic and non-pathogenic strains.Here we report transcriptional profiles of three closely related but phenotypically unique members of the Bacillus cereus group--a pneumonia-causing B. cereus strain (G9241, an attenuated strain of B. anthracis (Sterne 34F(2, and an avirulent B. cereus strain (10987--during exponential growth in two distinct atmospheric environments: 14% CO(2/bicarbonate and ambient air. We show that the disease-causing Bacillus strains undergo more distinctive transcriptional changes between the two environments, and that the expression of plasmid-encoded virulence genes was increased exclusively in the CO(2 environment. We observed a core of conserved metabolic genes that were differentially expressed in all three strains in both conditions. Additionally, the expression profiles of putative virulence genes in G9241 suggest that this strain, unlike Bacillus anthracis, may regulate gene expression with both PlcR and AtxA transcriptional regulators, each acting in a different environment.We have shown that homologous and even identical genes within the genomes of three closely related members of the B. cereus sensu lato group are in some instances regulated very differently, and that these differences can have important implications for virulence. This study provides insights into the evolution of the B. cereus group, and

Toxigenic genes, spoilage potential, and antimicrobial resistance of Bacillus cereus group strains from ice cream.

Science.gov (United States)

Arslan, Seza; Eyi, Ayla; Küçüksarı, Rümeysa

2014-02-01

Bacillus spp. can be recovered from almost every environment. It is also found readily in foods, where it may cause food spoilage and/or food poisoning due to its toxigenic and pathogenic nature, and extracellular enzymes. In this study, 29 Bacillus cereus group strains from ice cream were examined for the presence of following virulence genes hblC, nheA, cytK and ces genes, and tested for a range of the extracellular enzymes, and antimicrobial susceptibility. The strains were found to produce extracellular enzymes: proteolytic and lipolytic activity, gelatin hydrolysis and lecithinase production (100%), DNase production (93.1%) and amylase activity (93.1%). Of 29 strains examined, 24 (82.8%) showed hemolytic activity on blood agar. Beta-lactamase enzyme was only produced by 20.7% of B. cereus group. Among 29 B. cereus group from ice cream, nheA was the most common virulence gene detected in 44.8% of the strains, followed by hblC gene with 17.2%. Four (13.8%) of the 29 strains were positive for both hblC gene and nheA gene. Contrarily, cytK and ces genes were not detected in any of the strains. Antimicrobial susceptibility of ice cream isolates was tested to 14 different antimicrobial agents using the disc diffusion method. We detected resistance to penicillin and ampicillin with the same rate of 89.7%. Thirty-one percent of the strains were multiresistant to three or more antibiotics. This study emphasizes that the presence of natural isolates of Bacillus spp. harboring one or more enterotoxin genes, producing extracellular enzymes which may cause spoilage and acquiring antibiotic resistance might hold crucial importance in the food safety and quality. Copyright © 2013 Elsevier Ltd. All rights reserved.

Meningococcal B Vaccine Failure With a Penicillin-Resistant Strain in a Young Adult on Long-Term Eculizumab.

Science.gov (United States)

Parikh, Sydel R; Lucidarme, Jay; Bingham, Coralie; Warwicker, Paul; Goodship, Tim; Borrow, Ray; Ladhani, Shamez N

2017-09-01

We describe a case of invasive meningococcal disease due to a vaccine-preventable and penicillin-resistant strain in a fully immunized young adult on long-term complement inhibitor therapy and daily penicillin chemoprophylaxis. Eculizumab is a humanized monoclonal antibody that binds human complement C5 protein and inhibits the terminal complement pathway. It is currently recommended for the treatment of complement-mediated thrombotic microangiopathies. An unwanted complication of inhibiting complement, however, is an increased risk of invasive meningococcal disease. Here, we report the first case of meningococcal group B vaccine failure in a young adult receiving eculizumab for atypical hemolytic uremic syndrome. She developed invasive meningococcal disease due to a vaccine-preventable and penicillin-resistant meningococcal group B strain 4 months after receiving 2 doses of meningococcal group B vaccine while on oral penicillin prophylaxis against meningococcal infection. Copyright © 2017 by the American Academy of Pediatrics.

Draft genome sequence of Bacillus velezensis 2A-2B strain: a rhizospheric inhabitant of Sporobolus airoides (Torr.) Torr., with antifungal activity against root rot causing phytopathogens.

Science.gov (United States)

Martínez-Raudales, Inés; De La Cruz-Rodríguez, Yumiko; Alvarado-Gutiérrez, Alejandro; Vega-Arreguín, Julio; Fraire-Mayorga, Ahuitz; Alvarado-Rodríguez, Miguel; Balderas-Hernández, Victor; Fraire-Velázquez, Saúl

2017-01-01

A Bacillus velezensis strain from the rhizosphere of Sporobolus airoides (Torr.) Torr . , a grass in central-north México, was isolated during a biocontrol of phytopathogens scrutiny study. The 2A-2B strain exhibited at least 60% of growth inhibition of virulent isolates of phytopathogens causing root rot. These phytopathogens include Phytophthora capsici , Fusarium solani , Fusarium oxysporum and Rhizoctonia solani . Furthermore, the 2A-2B strain is an indolacetic acid producer, and a plant inducer of PR1, which is an induced systemic resistance related gene in chili pepper plantlets. Whole genome sequencing was performed to generate a draft genome assembly of 3.953 MB with 46.36% of GC content, and a N50 of 294,737. The genome contains 3713 protein coding genes and 89 RNA genes. Moreover, comparative genome analysis revealed that the 2A-2B strain had the greatest identity (98.4%) with Bacillus velezensis.

The next chapter for group B meningococcal vaccines.

Science.gov (United States)

Wang, N Y; Pollard, A J

2018-02-01

The majority of invasive meningococcal disease (IMD) in the developed world is caused by capsular group B Neisseria meningitidis, however success with vaccination against organisms bearing this capsule has previously been restricted to control of geographically limited clonal outbreaks. As we enter a new era, with the first routine program underway to control endemic group B meningococcal disease for infants in the UK, it is timely to review the key landmarks in group B vaccine development, and discuss the issues determining whether control of endemic group B disease will be achieved. Evidence of a reduction in carriage acquisition of invasive group B meningococcal strains, after vaccination among adolescents, is imperative if routine immunization is to drive population control of disease beyond those who are vaccinated (i.e. through herd immunity). The need for multiple doses to generate a sufficiently protective response and reactogenicity remain significant problems with the new generation of vaccines. Despite these limitations, early data from the UK indicate that new group B meningococcal vaccines have the potential to have a major impact on meningococcal disease, and to provide new insight into how we might do better in the future.

Commentary: Impact of meningococcal group B OMV vaccines, beyond their brief.

Science.gov (United States)

Petousis-Harris, Helen

2017-10-19

Meningococcal group B outer membrane vesicle vaccines have been used widely in Cuba, New Zealand, and Brazil. They are immunogenic and initially assessed largely by their ability to induce serum bactericidal activity. Measures of efficacy indicate good protection against homologous strains in older children and adults. Effectiveness appears broader than predicted by immunogenicity and efficacy studies. The recent discovery that meningococcal group B OMVs may protect against the related Neisseria species N.gonorrhoeae suggests more to these interesting antigen collections than meets the eye. Currently there are two OMV-containing group B vaccines available, the new recombinant protein-based Bexsero® developed by Novartis and VA-MENGOC-BC® developed by the Finlay institute in Cuba. Also, a third group B vaccine based on two recombinant factor H binding proteins (Trumenba®, Pfizer), has recently been licenced but it does not include OMV. This commentary explores the population impact that group B OMV vaccines have had on meningococcal and gonorrhoea diseases. Given the heterologous effect against diverse strains of the meningococcus observed in older children and adults, and recent evidence to suggest moderate protection against gonorrhoea, there may be a role for these vaccines in programmes targeting adolescents and groups high at risk for both meningococcal disease and gonorrhoea.

A meningococcal NOMV-FHbp vaccine for Africa elicits broader serum bactericidal antibody responses against serogroup B and non-B strains than a licensed serogroup B vaccine.

Science.gov (United States)

Pajon, Rolando; Lujan, Eduardo; Granoff, Dan M

2016-01-27

Meningococcal epidemics in Sub-Sahara caused by serogroup A strains are controlled by a group A polysaccharide conjugate vaccine. Strains with serogroups C, W and X continue to cause epidemics. Protein antigens in licensed serogroup B vaccines are shared among serogroup B and non-B strains. Compare serum bactericidal antibody responses elicited by an investigational native outer membrane vesicle vaccine with over-expressed Factor H binding protein (NOMV-FHbp) and a licensed serogroup B vaccine (MenB-4C) against African serogroup A, B, C, W and X strains. Human Factor H (FH) transgenic mice were immunized with NOMV-FHbp prepared from a mutant African meningococcal strain containing genetically attenuated endotoxin and a mutant sub-family B FHbp antigen with low FH binding, or with MenB-4C, which contains a recombinant sub-family B FHbp antigen that binds human FH, and three other antigens, NHba, NadA and PorA P1.4, capable of eliciting bactericidal antibody. The NOMV-FHbp elicited serum bactericidal activity against 12 of 13 serogroup A, B, W or X strains from Africa, and four isogenic serogroup B mutants with sub-family B FHbp sequence variants. There was no activity against a serogroup B mutant with sub-family A FHbp, or two serogroup C isolates from a recent outbreak in Northern Nigeria, which were mismatched for both PorA and sub-family of the FHbp vaccine antigen. For MenB-4C, NHba was expressed by all 16 African isolates tested, FHbp sub-family B in 13, and NadA in five. However, MenB-4C elicited titers ≥ 1:10 against only one isolate, and against only two of four serogroup B mutant strains with sub-family B FHbp sequence variants. NOMV-FHbp has greater potential to confer serogroup-independent protection in Africa than the licensed MenB-4C vaccine. However, the NOMV-FHbp vaccine will require inclusion of sub-family A FHbp for coverage against recent serogroup C strains causing outbreaks in Northern Nigeria. Copyright © 2015 Elsevier Ltd. All rights

Regulation of PI-2b Pilus Expression in Hypervirulent Streptococcus agalactiae ST-17 BM110.

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Bruno Périchon

Full Text Available The widely spread Streptococcus agalactiae (also known as Group B Streptococcus, GBS "hypervirulent" ST17 clone is strongly associated with neonatal meningitis. The PI-2b locus is mainly found in ST17 strains but is also present in a few non ST17 human isolates such as the ST-7 prototype strain A909. Here, we analysed the expression of the PI-2b pilus in the ST17 strain BM110 as compared to the non ST17 A909. Comparative genome analyses revealed the presence of a 43-base pair (bp hairpin-like structure in the upstream region of PI-2b operon in all 26 ST17 genomes, which was absent in the 8 non-ST17 strains carrying the PI-2b locus. Deletion of this 43-bp sequence in strain BM110 resulted in a 3- to 5-fold increased transcription of PI-2b. Characterization of PI-2b promoter region in A909 and BM110 strains was carried out by RNAseq, primer extension, qRT-PCR and transcriptional fusions with gfp as reporter gene. Our results indicate the presence of a single promoter (Ppi2b with a transcriptional start site (TSS mapped 37 bases upstream of the start codon of the first PI-2b gene. The large operon of 16 genes located upstream of PI-2b codes for the group B carbohydrate (also known as antigen B, a major constituent of the bacterial cell wall. We showed that the hairpin sequence located between antigen B and PI-2b operons is a transcriptional terminator. In A909, increased expression of PI-2b probably results from read-through transcription from antigen B operon. In addition, we showed that an extended 5' promoter region is required for maximal transcription of gfp as a reporter gene in S. agalactiae from Ppi2b promoter. Gene reporter assays performed in Lactococcus lactis strain NZ9000, a related non-pathogenic Gram-positive species, revealed that GBS-specific regulatory factors are required to drive PI-2b transcription. PI-2b expression is up-regulated in the BM110ΔcovR mutant as compared to the parental BM110 strain, but this effect is probably

Molecular characterization of an unauthorized genetically modified Bacillus subtilis production strain identified in a vitamin B2 feed additive.

Science.gov (United States)

Paracchini, Valentina; Petrillo, Mauro; Reiting, Ralf; Angers-Loustau, Alexandre; Wahler, Daniela; Stolz, Andrea; Schönig, Birgit; Matthies, Anastasia; Bendiek, Joachim; Meinel, Dominik M; Pecoraro, Sven; Busch, Ulrich; Patak, Alex; Kreysa, Joachim; Grohmann, Lutz

2017-09-01

Many food and feed additives result from fermentation of genetically modified (GM) microorganisms. For vitamin B2 (riboflavin), GM Bacillus subtilis production strains have been developed and are often used. The presence of neither the GM strain nor its recombinant DNA is allowed for fermentation products placed on the EU market as food or feed additive. A vitamin B 2 product (80% feed grade) imported from China was analysed. Viable B. subtilis cells were identified and DNAs of two bacterial isolates (LHL and LGL) were subjected to three whole genome sequencing (WGS) runs with different devices (MiSeq, 454 or HiSeq system). WGS data revealed the integration of a chloramphenicol resistance gene, the deletion of the endogenous riboflavin (rib) operon and presence of four putative plasmids harbouring rib operons. Event- and construct-specific real-time PCR methods for detection of the GM strain and its putative plasmids in food and feed products have been developed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characterization of Escherichia coli Phylogenetic Groups ...

African Journals Online (AJOL)

Background: Escherichia coli strains mainly fall into four phylogenetic groups (A, B1, B2, and D) and that virulent extra‑intestinal strains mainly belong to groups B2 and D. Aim: The aim was to determine the association between phylogenetic groups of E. coli causing extraintestinal infections (ExPEC) regarding the site of ...

Whole-gene analysis of two groups of hepatitis B virus C/D inter-genotype recombinant strains isolated in Tibet, China.

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Tiezhu Liu

Full Text Available Tibet is a highly hepatitis B virus (HBV endemic area. Two types of C/D recombinant HBV are commonly isolated in Tibet and have been previously described. In an effort to better understand the molecular characteristic of these C/D recombinant strains from Tibet, we undertook a multistage random sampling project to collect HBsAg positive samples. Molecular epidemiological and bio-informational technologies were used to analyze the characteristics of the sequences found in this study. There were 60 samples enrolled in the survey, and we obtained 19 whole-genome sequences. 19 samples were all C/D recombinant, and could be divided into two sub-types named C/D1 and C/D2 according to the differences in the location of the recombinant breakpoint. The recombination breakpoint of the 10 strains belonging to the C/D1 sub-type was located at nt750, while the 9 stains belonging to C/D2 had their recombination break point at nt1530. According to whole-genome sequence analysis, the 19 identified strains belong to genotype C, but the nucleotide distance was more than 5% between the 19 strains and sub-genotypes C1 to C15. The distance between C/D1with C2 was 5.8±2.1%, while the distance between C/D2 with C2 was 6.4±2.1%. The parental strain was most likely sub-genotype C2. C/D1 strains were all collected in the middle and northern areas of Tibet including Lhasa, Linzhi and Ali, while C/D2 was predominant in Shannan in southern Tibet. This indicates that the two recombinant genotypes are regionally distributed in Tibet. These results provide important information for the study of special HBV recombination events, gene features, virus evolution, and the control and prevention policy of HBV in Tibet.

Antibiotic susceptibility profiles for group B streptococci isolated from neonates, 1995-1998

NARCIS (Netherlands)

Lin, FYC; Azimi, PH; Weisman, LE; Philips, JB; Regan, J; Clark, P; Rhoads, GG; Clemens, J; Troendle, J; Pratt, E; Brenner, RA; Gill, [No Value

Antibiotic susceptibility profiles were analyzed for 119 invasive and 227 colonizing strains of group B streptococci isolated from neonates at 6 US academic centers, All strains were susceptible to penicillin, vancomycin, chloramphenicol, and cefotaxime, The rate of resistance to erythromycin was

Gibberellic acid, amino acids (glycine and L-leucine), vitamin B2 ...

African Journals Online (AJOL)

SAM

2014-03-14

Mar 14, 2014 ... vitamin B2 and zinc as factors affecting the production pigments by Monascus ..... in a nitrogen-deficient medium, the B-group vitamins, both single ... citrinin production in the industrial important strain Monascus purpureus ...

Mechanical properties and bending strain effect on Cu-Ni sheathed MgB2 superconducting tape

International Nuclear Information System (INIS)

Fu, Minyi; Chen, Jiangxing; Jiao, Zhengkuan; Kumakura, H.; Togano, K.; Ding, Liren; Zhang, Yong; Chen, Zhiyou; Han, Hanmin; Chen, Jinglin

2004-01-01

The Young's modulus (E) of Cu-Ni sheathed MgB 2 monofilament tape was measured using electric method. It is about 8.05 x 10 10 Pa, the same order of Cu and its alloys. We found that the lower E value of the MgB 2 component seemed to relate to the lower filament density. The benefits of pre-compression in filaments were discussed in terms of improving stress distribution in the wires and tapes during winding and operation of superconducting magnets. The magnetic field dependence of J c was investigated on the sample subjected to various strain levels through bending with different radii at 4.2 K

Strain ageing of nuclear pressure vessel steels A533B and A508 cl.2

International Nuclear Information System (INIS)

Pelli, R.; Toerroenen, K.

1978-04-01

The susceptibility of the reactor pressure vessel steels A533B and A508 cl.2 to strain ageing has been studied using conventional tensile and impact testing of prestrained and aged specimens. The results show a modest susceptibility, seen as an increase in yield strength and Charpy V transition temperatures. The effect of varying alloying additions within the range of normal production was not observed, but the initial mechanical properties clearly affect the strain ageing. The lower the initial yield strength, the higher increase in strength and the lower increase in transition temperature is observed. (author)

Association of meningococcal serotypes with the course of disease: serotypes 2a and 2b in the Netherlands, 1959-1981

NARCIS (Netherlands)

Spanjaard, L.; Bol, P.; de Marie, S.; Zanen, H. C.

1987-01-01

Case histories of 692 patients with meningococcal disease due to serogroup B, C, or W (W-135) were reviewed to study the association of the serotypes 2a and 2b with the course of disease. The case-fatality rate in group B disease was significantly associated with serotype 2b (B:2b) strains (P =

Susceptibility of clinical isolates of Bacteroides fragilis group strains to cefoxitin, cefoperazone and ticarcillin/clavulanate

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PEIXOTO JÚNIOR Arnaldo Aires

2000-01-01

Full Text Available A total of 40 strains of the B. fragilis group was isolated from clinical specimens in two hospital centers in Fortaleza from 1993 to 1997. The most frequently isolated species was Bacteroides fragilis (19 strains and most isolates came from intra-abdominal and wound infections. The susceptibility profile was traced for cefoxitin, cefoperazone and ticarcillin-clavulanate by using the agar dilution reference method. All isolates were susceptible to ticarcillin-clavulanate (128/2mug/ml. Resistance rates of 15 and 70% were detected to cefoxitin (64mug/ml and cefoperazone (64mug/ml, respectively. Such regional results permit a better orientation in choosing this group of antibiotics for prophylaxis and therapy especially in relation to cefoxitin, which is frequently used in the hospital centers studied.

Different strain relaxation mechanisms in strained Si/Si sub 1 sub - sub x Ge sub x /Si heterostructures by high dose B sup + and BF sub 2 sup + doping

CERN Document Server

Chen, C C; Zhang, S L; Zhu, D Z; Vantomme, A

2002-01-01

Strained Si/Si sub 0 sub . sub 8 Ge sub 0 sub . sub 2 /Si heterostructures are implanted at room temperature with 7.5 keV B sup + and 33 keV BF sub 2 sup + ions to a high dose of 2x10 sup 1 sup 5 ions/cm sup 2 , respectively. The samples are subsequently subjected to three-step anneals (spacer anneal, oxidation anneal and rapid thermal anneal), which are used to simulate a real fabrication process of SiGe-based MOSFET devices. The damage induced by implantation and its recovery are characterized by 2 MeV sup 4 He sup + RBS/channeling spectrometry. A damage layer on the surface is induced by B sup + implantation, but BF sup + sub 2 ion implantation amorphizes the surface of Si/Si sub 0 sub . sub 8 Ge sub 0 sub . sub 2 /Si heterostructure. Channeling angular scans along the axial direction demonstrate that the strain stored in the SiGe layer could be nearly completely retained for the B sup + implanted and subsequently annealed sample. However, the strain in the BF sub 2 sup + implanted/annealed SiGe layer has...

Sulfate as a pivotal factor in regulation of Serratia sp. strain S2B pigment biosynthesis.

Science.gov (United States)

Rastegari, Banafsheh; Karbalaei-Heidari, Hamid Reza

2016-10-01

In the present work, we investigated the prodiginine family as secondary metabolite members. Bacterial strain S2B, with the ability to produce red pigment, was isolated from the Sarcheshmeh copper mine in Iran. 16S rDNA gene sequencing revealed that the strain was placed in the Serratia genus. Pigment production was optimized using low-cost culture medium and the effects of various physicochemical factors were studied via statistical approaches. Purification of the produced pigment by silica gel column chromatography showed a strong red pigment fraction and a weaker orange band. Mass spectrometry, FT-IR spectroscopy and (1)H NMR analysis revealed that the red pigment was prodigiosin and the orange band was a prodigiosin-like analog, with molecular weights of 323 and 317 Da, respectively. Genotoxicity and cytotoxicity studies confirmed their membership in the prodiginine family. Analysis of the production pattern of the pigments in the presence of different concentrations of ammonium salts revealed the role of sulfate as an important factor in regulation of the pigment biosynthesis pathway. Overall, the data showed that regulation of the pigment biosynthesis pathway in Serratia sp. strain S2B was affected by inorganic micronutrients, particularly the sulfate ions. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Post-UV colony-forming ability of normal fibroblast strains and of the xeroderma pigmentosum group G strain

International Nuclear Information System (INIS)

Barrett, S.F.; Tarone, R.E.; Moshell, A.N.; Ganges, M.B.; Robbins, J.H.

1981-01-01

In xeroderma pigmentosum, an inherited disorder of defective DNA repair, post-uv colony-forming ability of fibroblasts from patients in complementation groups A through F correlates with the patients' neurological status. The first xeroderma pigmentosum patient assigned to the recently discovered group G had the neurological abnormalities of XP. Researchers have determined the post-uv colony-forming ability of cultured fibroblasts from this patient and from 5 more control donors. Log-phase fibroblasts were irradiated with 254 nm uv light from a germicidal lamp, trypsinized, and replated at known densities. After 2 to 4 weeks' incubation the cells were fixed, stained and scored for colony formation. The strains' post-uv colony-forming ability curves were obtained by plotting the log of the percent remaining post-uv colony-forming ability as a function of the uv dose. The post-uv colony-forming ability of 2 of the 5 new normal strains was in the previously defined control donor zone, but that of the other 3 extended down to the level of the most resistant xeroderma pigmentosum strain. The post-uv colony-forming ability curve of the group G fibroblasts was not significantly different from the curves of the group D fibroblast strains from patients with clinical histories similar to that of the group G patient

Identification and strain differentiation of 'Bacteroides fragilis group' species and Prevotella bivia by PCR fingerprinting.

Science.gov (United States)

Claros, M; Schönian, G; Gräser, Y; Montag, T; Rodloff, A C; Citron, D M; Goldstein, E J

1995-08-01

Using single consensus primers of genomic nucleotide sequences, PCR-generated fingerprints were used for identification and differentiation of the Bacteroides fragilis group (B. fragilis, B. thetaiotaomicron, B. ovatus, B. distasonis, B. vulgatus) and Prevotella bivia (B. bivius) by comparing the DNA profiles with those of reference strains from the American Type Culture Collection and German Culture Collection. When primed by a single primer phage M13 core sequence, intra-species specific differences and species-specific bands were detected. Using primers derived from the evolutionarily conserved tRNA gene sequence, species-specific patterns were produced. A computer program, GelManager, was used to analyze the profiles and generate dendrograms. The correlation coefficients determined from the DNA fingerprint profiles of the clinical isolates (using the M13 core primer) fell within a narrow range, reflecting a high level of homology within the species. Based on the dendrograms, strains of one species were clearly differentiated from strains of other species. For comparison, SDS-PAGE analysis of whole cell extracts was also performed to obtain protein band patterns of various strains. Because of the simplicity of the PCR fingerprinting method and the ease of performance of computerized evaluation of data, this technique is a useful method for both species and strain differentiation, as well as for characterization of Bacteroides species and Prevotella bivia.

Prior Inoculation with Type B Strains of Francisella tularensis Provides Partial Protection against Virulent Type A Strains in Cottontail Rabbits.

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Vienna R Brown

Full Text Available Francisella tularensis is a highly virulent bacterium that is capable of causing severe disease (tularemia in a wide range of species. This organism is characterized into two distinct subspecies: tularensis (type A and holarctica (type B which vary in several crucial ways, with some type A strains having been found to be considerably more virulent in humans and laboratory animals. Cottontail rabbits have been widely implicated as a reservoir species for this subspecies; however, experimental inoculation in our laboratory revealed type A organisms to be highly virulent, resulting in 100% mortality following challenge with 50-100 organisms. Inoculation of cottontail rabbits with the same number of organisms from type B strains of bacteria was found to be rarely lethal and to result in a robust humoral immune response. The objective of this study was to characterize the protection afforded by a prior challenge with type B strains against a later inoculation with a type A strain in North American cottontail rabbits (Sylvilagus spp. Previous infection with a type B strain of organism was found to lengthen survival time and in some cases prevent death following inoculation with a type A2 strain of F. tularensis. In contrast, inoculation of a type A1b strain was uniformly lethal in cottontail rabbits irrespective of a prior type B inoculation. These findings provide important insight about the role cottontail rabbits may play in environmental maintenance and transmission of this organism.

The L2b real-time PCR targeting the pmpH gene of Chlamydia trachomatis used for the diagnosis of lymphogranuloma venereum is not specific to L2b strains.

Science.gov (United States)

Touati, A; Peuchant, O; Hénin, N; Bébéar, C; de Barbeyrac, B

2016-06-01

The French Reference Centre for chlamydiae uses two real-time PCRs targeting the pmpH gene of Chlamydia trachomatis to differentiate between L strains and variant L2b, responsible for a lymphogranuloma venereum outbreak in Europe. We compared the results obtained for 122 L2b C. trachomatis-positive specimens, using the two real-time PCRs, with the sequencing of the ompA gene. Only 91 specimens were confirmed as L2b. Our results demonstrate that the lymphogranuloma venereum outbreak is no longer dominated by the variant L2b, and that many L-positive specimens were misidentified as L2b with the method used, which raises the question of its specificity. Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Production of Fumonisin B-2 and B-4 by Aspergillus niger on Grapes and Raisins

DEFF Research Database (Denmark)

Mogensen, Jesper Mølgaard; Frisvad, Jens Christian; Thrane, Ulf

2010-01-01

The recent discovery of fumonisin production in Aspergillus niger, raises concerns about the presence of these mycotoxins in grapes and raisins as well as other commodities where A. niger is a frequent contaminant. Here we investigate the potential production of fumonisins in A. niger cultured...... on grapes and raisins. Sixty-six A. niger, 4 A. tubingensis, and 16 A. acidus strains isolated from raisins were tested for fumonisin production on laboratory media. Neither A. tubingensis nor A. acidus strains produced fumonisins, but 77% of A. niger strains did. None of the strains produced ochratoxin A....... Ten selected fumonisin producing A. niger strains were further able to produce fumonisin B2 and fumonisin B4 on grapes in the range 171−7841 μg fumonisin B2/kg and 14−1157 μg fumonisin B4/kg. Four selected strains were able to produce fumonisin B2 (5−6476 μg/kg) and fumonisin B4 (12−672 μg...

A Single Coxsackievirus B2 Capsid Residue Controls Cytolysis and Apoptosis in Rhabdomyosarcoma Cells

DEFF Research Database (Denmark)

Gullberg, M.; Tolf, C.; Jonsson, N.

2010-01-01

Coxsackievirus B2 (CVB2), one of six human pathogens of the group B coxsackieviruses within the enterovirus genus of Picornaviridae, causes a wide spectrum of human diseases ranging from mild upper respiratory illnesses to myocarditis and meningitis. The CVB2 prototype strain Ohio-1 (CVB2O...

Multilocus sequence analysis and rpoB sequencing of Mycobacterium abscessus (sensu lato) strains.

Science.gov (United States)

Macheras, Edouard; Roux, Anne-Laure; Bastian, Sylvaine; Leão, Sylvia Cardoso; Palaci, Moises; Sivadon-Tardy, Valérie; Gutierrez, Cristina; Richter, Elvira; Rüsch-Gerdes, Sabine; Pfyffer, Gaby; Bodmer, Thomas; Cambau, Emmanuelle; Gaillard, Jean-Louis; Heym, Beate

2011-02-01

Mycobacterium abscessus, Mycobacterium bolletii, and Mycobacterium massiliense (Mycobacterium abscessus sensu lato) are closely related species that currently are identified by the sequencing of the rpoB gene. However, recent studies show that rpoB sequencing alone is insufficient to discriminate between these species, and some authors have questioned their current taxonomic classification. We studied here a large collection of M. abscessus (sensu lato) strains by partial rpoB sequencing (752 bp) and multilocus sequence analysis (MLSA). The final MLSA scheme developed was based on the partial sequences of eight housekeeping genes: argH, cya, glpK, gnd, murC, pgm, pta, and purH. The strains studied included the three type strains (M. abscessus CIP 104536(T), M. massiliense CIP 108297(T), and M. bolletii CIP 108541(T)) and 120 isolates recovered between 1997 and 2007 in France, Germany, Switzerland, and Brazil. The rpoB phylogenetic tree confirmed the existence of three main clusters, each comprising the type strain of one species. However, divergence values between the M. massiliense and M. bolletii clusters all were below 3% and between the M. abscessus and M. massiliense clusters were from 2.66 to 3.59%. The tree produced using the concatenated MLSA gene sequences (4,071 bp) also showed three main clusters, each comprising the type strain of one species. The M. abscessus cluster had a bootstrap value of 100% and was mostly compact. Bootstrap values for the M. massiliense and M. bolletii branches were much lower (71 and 61%, respectively), with the M. massiliense cluster having a fuzzy aspect. Mean (range) divergence values were 2.17% (1.13 to 2.58%) between the M. abscessus and M. massiliense clusters, 2.37% (1.5 to 2.85%) between the M. abscessus and M. bolletii clusters, and 2.28% (0.86 to 2.68%) between the M. massiliense and M. bolletii clusters. Adding the rpoB sequence to the MLSA-concatenated sequence (total sequence, 4,823 bp) had little effect on the

Genetic Regulation of Guanylate-Binding Proteins 2b and 5 during Leishmaniasis in Mice

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Sohrabi, Yahya; Volkova, Valeryia; Kobets, Tatyana; Havelková, Helena; Krayem, Imtissal; Slapničková, Martina; Demant, Peter; Lipoldová, Marie

2018-01-01

Interferon-induced GTPases [guanylate-binding proteins (GBPs)] play an important role in inflammasome activation and mediate innate resistance to many intracellular pathogens, but little is known about their role in leishmaniasis. We therefore studied expression of Gbp2b/Gbp1 and Gbp5 mRNA in skin, inguinal lymph nodes, spleen, and liver after Leishmania major infection and in uninfected controls. We used two different groups of related mouse strains: BALB/c, STS, and CcS-5, CcS-16, and CcS-20 that carry different combinations of BALB/c and STS genomes, and strains O20, C57BL/10 (B10) and B10.O20, OcB-9, and OcB-43 carrying different combinations of O20 and B10 genomes. The strains were classified on the basis of size and number of infection-induced skin lesions as highly susceptible (BALB/c, CcS-16), susceptible (B10.O20), intermediate (CcS-20), and resistant (STS, O20, B10, OcB-9, OcB-43). Some uninfected strains differed in expression of Gbp2b/Gbp1 and Gbp5, especially of Gbp2b/Gbp1 in skin. Uninfected BALB/c and STS did not differ in their expression, but in CcS-5, CcS-16, and CcS-20, which all carry BALB/c-derived Gbp gene-cluster, expression of Gbp2b/Gbp1 exceeds that of both parents. These data indicate trans-regulation of Gbps. Infection resulted in approximately 10× upregulation of Gbp2b/Gbp1 and Gbp5 mRNAs in organs of both susceptible and resistant strains, which was most pronounced in skin. CcS-20 expressed higher level of Gbp2b/Gbp1 than both parental strains in skin, whereas CcS-16 expressed higher level of Gbp2b/Gbp1 than both parental strains in skin and liver. This indicates a trans-regulation present in infected mice CcS-16 and CcS-20. Immunostaining of skin of five strains revealed in resistant and intermediate strains STS, CcS-5, O20, and CcS-20 tight co-localization of Gbp2b/Gbp1 protein with most L. major parasites, whereas in the highly susceptible strain, BALB/c most parasites did not associate with Gbp2b/Gbp1. In conclusion, expression of

Genetic characterization of enterovirus strains identified in Hand, Foot and Mouth Disease (HFMD): Emergence of B1c, C1 subgenotypes, E2 sublineage of CVA16, EV71 and CVA6 strains in India.

Science.gov (United States)

Ganorkar, Nital N; Patil, Pooja R; Tikute, Sanjay S; Gopalkrishna, Varanasi

2017-10-01

Hand, Foot and Mouth disease (HFMD) is a common childhood disease and caused due to Enterovirus-A (EV-A), EV-B and EV-C species worldwide. Cases of HFMD were reported from, Ahmedabad (Gujarat, 2012) and Pune (Maharashtra, 2013-2014) in India. The present study highlights the identification of EV strains (CVA16, CVA6, CVA4 and Echo12), characterization of subgenotypes of CVA16, CVA6 strains during 2012-14 and CVA16, CVA6, EV71 strains reported from the earlier study (2009-10) in HFMD cases from India. A total 158 clinical specimens collected from 64 HFMD cases (2012-2014) were included in the study. EV detection was carried out by 5'NCR based RT-PCR, molecular typing and subgenotyping was by VP1/2A junction or VP1, full VP1 gene amplification respectively followed by phylogenetic analysis. The present study reports 63.92% (101/158) EV positivity by RT-PCR. Ninety four of the 101 (93.06%) EV positive strains were amplified by VP1/2A junction or VP1 regions. Sequence analysis revealed the presence of CVA16 (61.7%), CVA6 (34.04%), CVA4 and Echo12 (4.3%). A total of 114 EV positive strains were genotyped using full and partial VP1 region. All CVA16 Indian strains (n=70) clustered with rarely reported B1c subgenotype, CVA6 (n=43) and EV71 (n=1) strains clustered with sub-lineage E2 and C1 subgenotypes respectively. In summary, the study reports genetic characterization of CVA16, CVA6, CVA4 and Echo12 strains in HFMD cases from India. Circulation of B1c subgenotype of CVA16, E2 sub-lineage of CVA6 and C1 subgenotype of EV 71 strains in HFMD cases were reported for the first time from India. This study helps to understand the genotype distribution, genetic diversity of EV strains associated with HFMD from Eastern, Western and Southern regions in India. Copyright © 2017 Elsevier B.V. All rights reserved.

A phase 1 study of a group B meningococcal native outer membrane vesicle vaccine made from a strain with deleted lpxL2 and synX and stable expression of opcA.

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Keiser, Paul B; Gibbs, Barnett T; Coster, Trinka S; Moran, E Ellen; Stoddard, Mark B; Labrie, Joseph E; Schmiel, Deborah H; Pinto, Valerian; Chen, Ping; Zollinger, Wendell D

2010-10-08

This phase 1 clinical trial assessed the safety and immunogenicity of a native outer membrane vesicle (NOMV) vaccine prepared from a lpxL2(-) synX(-) mutant of strain 44/76 with opcA expression stabilized. Thirty-four volunteers were assigned to one of the three dose groups (25 mcg, 25 mcg with aluminum hydroxide adjuvant, and 50 mcg) to receive three intramuscular injections at 0, 6 and 24 weeks. Specific local and systemic adverse events (AEs) were solicited by diary and at visits on days 1, 2, 7 and 14 after each vaccination and at the end of the study at 30 weeks. Blood chemistries, complete blood count, and coagulation studies were measured on each vaccination day and again two days later. Blood for antibody measurements and bactericidal assays were drawn 0, 14, and 42 days after each vaccination. The proportion of volunteers who developed a fourfold or greater increase in serum bactericidal activity (SBA) to the wild-type parent of the vaccine strain with high opcA expression at 6 weeks after the third dose was 12/26 (0.46, 95% confidence interval 0.27-0.65). Antibody levels to OpcA were significantly higher in vaccine responders than in non-responders (p=0.008), and there was a trend for higher antibody levels to the lipooligosaccharide (LOS) (p=0.059). Bactericidal depletion assays on sera from volunteers with high-titer responses also indicate a major contribution of anti-OpcA and anti-LOS antibodies to the bactericidal response.These results suggest that genetically modified NOMV vaccines can induce protection against group B meningococcus. Copyright © 2010 Elsevier Ltd. All rights reserved.

Phylogenetic analysis of Mycobacterium massiliense strains having recombinant rpoB gene laterally transferred from Mycobacterium abscessus.

Science.gov (United States)

Kim, Byoung-Jun; Kim, Ga-Na; Kim, Bo-Ram; Shim, Tae-Sun; Kook, Yoon-Hoh; Kim, Bum-Joon

2017-01-01

Recent multi locus sequence typing (MLST) and genome based studies indicate that lateral gene transfer (LGT) events in the rpoB gene are prevalent between Mycobacterium abscessus complex strains. To check the prevalence of the M. massiliense strains subject to rpoB LGT (Rec-mas), we applied rpoB typing (711 bp) to 106 Korean strains of M. massiliense infection that had already been identified by hsp65 sequence analysis (603 bp). The analysis indicated 6 smooth strains in M. massiliense Type I (10.0%, 6/60) genotypes but no strains in M. massiliense Type II genotypes (0%, 0/46), showing a discrepancy between the 2 typing methods. Further MLST analysis based on the partial sequencing of seven housekeeping genes, argH, cya, glpK, gnd, murC, pta and purH, as well as erm(41) PCR proved that these 6 Rec-mas strains consisted of two distinct genotypes belonging to M. massiliense and not M. abscessus. The complete rpoB sequencing analysis showed that these 6 Rec-mas strains have an identical hybrid rpoB gene, of which a 478 bp partial rpoB fragment may be laterally transferred from M. abscessus. Notably, five of the 6 Rec-mas strains showed complete identical sequences in a total of nine genes, including the seven MLST genes, hsp65, and rpoB, suggesting their clonal propagation in South Korea. In conclusion, we identified 6 M. massiliense smooth strains of 2 phylogenetically distinct genotypes with a specific hybrid rpoB gene laterally transferred from M. abscessus from Korean patients. Their clinical relevance and bacteriological traits remain to be elucidated.

Phylogenetic analysis of Mycobacterium massiliense strains having recombinant rpoB gene laterally transferred from Mycobacterium abscessus.

Directory of Open Access Journals (Sweden)

Byoung-Jun Kim

Full Text Available Recent multi locus sequence typing (MLST and genome based studies indicate that lateral gene transfer (LGT events in the rpoB gene are prevalent between Mycobacterium abscessus complex strains. To check the prevalence of the M. massiliense strains subject to rpoB LGT (Rec-mas, we applied rpoB typing (711 bp to 106 Korean strains of M. massiliense infection that had already been identified by hsp65 sequence analysis (603 bp. The analysis indicated 6 smooth strains in M. massiliense Type I (10.0%, 6/60 genotypes but no strains in M. massiliense Type II genotypes (0%, 0/46, showing a discrepancy between the 2 typing methods. Further MLST analysis based on the partial sequencing of seven housekeeping genes, argH, cya, glpK, gnd, murC, pta and purH, as well as erm(41 PCR proved that these 6 Rec-mas strains consisted of two distinct genotypes belonging to M. massiliense and not M. abscessus. The complete rpoB sequencing analysis showed that these 6 Rec-mas strains have an identical hybrid rpoB gene, of which a 478 bp partial rpoB fragment may be laterally transferred from M. abscessus. Notably, five of the 6 Rec-mas strains showed complete identical sequences in a total of nine genes, including the seven MLST genes, hsp65, and rpoB, suggesting their clonal propagation in South Korea. In conclusion, we identified 6 M. massiliense smooth strains of 2 phylogenetically distinct genotypes with a specific hybrid rpoB gene laterally transferred from M. abscessus from Korean patients. Their clinical relevance and bacteriological traits remain to be elucidated.

Strain-dependent effects of diazepam and the 5-HT2B/2C receptor antagonist SB 206553 in spontaneously hypertensive and Lewis rats tested in the elevated plus-maze

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Takahashi R.N.

2001-01-01

Full Text Available The 5-HT2B/2C receptor antagonist SB 206553 exerts anxiolytic effects in rat models of anxiety. However, these effects have been reported for standard rat strains, thus raising the issue of SB 206553 effects in rat strains displaying different levels of anxiety. Herein, the effects of SB 206553 in a 5-min elevated plus-maze test of anxiety were compared to those of the reference anxiolytic, diazepam, in two rat strains respectively displaying high (Lewis rats and low (spontaneously hypertensive rats, SHR anxiety. Diazepam (0.37, 0.75, or 1.5 mg/kg; 30 min before testing increased in a dose-dependent manner the behavioral measures in SHR, but not in Lewis rats. On the other hand, SB 206553 (1.25, 2.5, or 5 mg/kg; 30 min before testing failed to alter the anxiety parameters in both strains, whereas it increased closed arm entries in Lewis rats, suggesting that it elicited hyperactivity in the latter strain. Accordingly, the hypolocomotor effect of the nonselective 5-HT2B/2C receptor agonist m-chlorophenylpiperazine (1.5 mg/kg ip 20 min before a 15-min exposure to an activity cage was prevented by the 1.25 and 2.5 mg/kg doses of SB 206553 in Lewis rats and SHR, respectively. Compared with SHR, Lewis rats may display a lower response to benzodiazepine-mediated effects and a more efficient control of locomotor activity by 5-HT2B/2C receptors.

The genome sequence of Brucella pinnipedialis B2/94 sheds light on the evolutionary history of the genus Brucella

Science.gov (United States)

2011-01-01

Background Since the discovery of the Malta fever agent, Brucella melitensis, in the 19th century, six terrestrial mammal-associated Brucella species were recognized over the next century. More recently the number of novel Brucella species has increased and among them, isolation of species B. pinnipedialis and B. ceti from marine mammals raised many questions about their origin as well as on the evolutionary history of the whole genus. Results We report here on the first complete genome sequence of a Brucella strain isolated from marine mammals, Brucella pinnipedialis strain B2/94. A whole gene-based phylogenetic analysis shows that five main groups of host-associated Brucella species rapidly diverged from a likely free-living ancestor close to the recently isolated B. microti. However, this tree lacks the resolution required to resolve the order of divergence of those groups. Comparative analyses focusing on a) genome segments unshared between B. microti and B. pinnipedialis, b) gene deletion/fusion events and c) positions and numbers of Brucella specific IS711 elements in the available Brucella genomes provided enough information to propose a branching order for those five groups. Conclusions In this study, it appears that the closest relatives of marine mammal Brucella sp. are B. ovis and Brucella sp. NVSL 07-0026 isolated from a baboon, followed by B. melitensis and B. abortus strains, and finally the group consisting of B. suis strains, including B. canis and the group consisting of the single B. neotomae species. We were not able, however, to resolve the order of divergence of the two latter groups. PMID:21745361

Mutagenesis at the ad-3A and ad-3B loci in haploid UV-sensitive strains of Neurospora crassa. Pt. 2

International Nuclear Information System (INIS)

Serres, F.J. de

1980-01-01

UV-induced inactivation and induction of mutations at the ad-3A and ad-3B loci of Neurospora crassa have been compared among 7 different UV-sensitive strains and a standard wild-type strain. The 7 strains show varying degrees of sensitivity to UV-induced inactivation, with the relative sensitivity being: uvs-2 > uvs-3 > uvs-4 > uvs-6 > upr-1 > uvs-5 > uvs-1. Studies on the induction of ad-3 mutants by UV show that the 2 excision-repair deficient mutants uvs-2 and upr-1 exhibit enhanced ad-3 mutant frequencies, while uvs-4 and uvs-5 exhibit reduced ad-3 mutant frequencies, and uvs-3 completely eliminates UV mutagenesis. The ad-3 mutation-induction curves obtained with uvs-1 or uvs-6 are not significantly different from that found with the wild-type strain. (orig.)

Vaccines for the prevention of meningococcal capsular group B disease: What have we recently learned?

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Findlow, Jamie

2016-01-01

Meningococcal disease remains a feared and devastating cause of sepsis and meningitis. Disease incidence is highest among infants and children although a significant burden of disease is experienced by adolescents, young adults and those with specific risk-factors. Prevention of disease against capsular groups A, C, W and Y; 4 of the 5 most pathogenic groups is achievable using capsular polysaccharide vaccines. It has only recently been possible to provide protection against capsular group B (MenB) strains following the licensure of a 4 component group B vaccine (4CMenB) in Europe in 2013. Following licensure, 4CMenB has been used in specific at-risk groups and in response to outbreaks of MenB disease. The largest outbreak interventions have been in students at 2 universities in the United States and for all individuals aged 2 months to 20 years of age in Quebec, Canada. The vaccine was recommended in February 2014 for implementation into the UK infant schedule at 2, 4 and 12 months of age, although it has taken over 12 months to resolve procurement discussions to enable implementation. The UK recommendation incorporates prophylactic paracetamol with infant doses when 4CMenB is administered concomitantly with routine vaccines. This is based on recent data demonstrating the ability of paracetamol to reduce fever rates to background levels without impacting immunogenicity. Post-implementation surveillance will be important to provide vaccine efficacy data as this was not possible to determine in pre-licensure studies due to the relative infrequency of MenB cases.

Purification, crystallization and preliminary crystallographic analysis of DehI, a group I α-haloacid dehalogenase from Pseudomonas putida strain PP3

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Schmidberger, Jason W. [School of Pharmacology and Medicine, University of Western Australia, Crawley, Western Australia (Australia); Wilce, Jackie A. [Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria (Australia); Weightman, Andrew J. [School of Biosciences, Cardiff University, Cardiff,Wales (United Kingdom); Wilce, Matthew C. J., E-mail: matthew.wilce@med.monash.edu.au [Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria (Australia); School of Pharmacology and Medicine, University of Western Australia, Crawley, Western Australia (Australia)

2008-07-01

The α-haloacid dehalogenase DehI from P. putida strain PP3 was cloned into a vector with an N-terminal His tag and expressed in E. coli Nova Blue strain. Purified protein was crystallized in a primitive monoclinic form and a complete native data set was collected and analysed. Pseudomonas putida strain PP3 produces two dehalogenases, DehI and DehII, which belong to the group I and II α-haloacid dehalogenases, respectively. Group I dehalogenases catalyse the removal of halides from d-haloalkanoic acids and in some cases also the l-enantiomers, both substituted at their chiral centres. Studies of members of this group have resulted in the proposal of general catalytic mechanisms, although no structural information is available in order to better characterize their function. This work presents the initial stages of the structural investigation of the group I α-haloacid dehalogenase DehI. The DehI gene was cloned into a pET15b vector with an N-terminal His tag and expressed in Escherichia coli Nova Blue strain. Purified protein was crystallized in 25% PEG 3350, 0.4 M lithium sulfate and 0.1 M bis-tris buffer pH 6.0. The crystals were primitive monoclinic (space group P2{sub 1}), with unit-cell parameters a = 68.32, b = 111.86, c = 75.13 Å, α = 90, β = 93.7, γ = 90°, and a complete native data set was collected. Molecular replacement is not an option for structure determination, so further experimental phasing methods will be necessary.

Purification, crystallization and preliminary crystallographic analysis of DehI, a group I α-haloacid dehalogenase from Pseudomonas putida strain PP3

International Nuclear Information System (INIS)

Schmidberger, Jason W.; Wilce, Jackie A.; Weightman, Andrew J.; Wilce, Matthew C. J.

2008-01-01

The α-haloacid dehalogenase DehI from P. putida strain PP3 was cloned into a vector with an N-terminal His tag and expressed in E. coli Nova Blue strain. Purified protein was crystallized in a primitive monoclinic form and a complete native data set was collected and analysed. Pseudomonas putida strain PP3 produces two dehalogenases, DehI and DehII, which belong to the group I and II α-haloacid dehalogenases, respectively. Group I dehalogenases catalyse the removal of halides from d-haloalkanoic acids and in some cases also the l-enantiomers, both substituted at their chiral centres. Studies of members of this group have resulted in the proposal of general catalytic mechanisms, although no structural information is available in order to better characterize their function. This work presents the initial stages of the structural investigation of the group I α-haloacid dehalogenase DehI. The DehI gene was cloned into a pET15b vector with an N-terminal His tag and expressed in Escherichia coli Nova Blue strain. Purified protein was crystallized in 25% PEG 3350, 0.4 M lithium sulfate and 0.1 M bis-tris buffer pH 6.0. The crystals were primitive monoclinic (space group P2 1 ), with unit-cell parameters a = 68.32, b = 111.86, c = 75.13 Å, α = 90, β = 93.7, γ = 90°, and a complete native data set was collected. Molecular replacement is not an option for structure determination, so further experimental phasing methods will be necessary

7 CFR 29.1162 - Leaf (B Group).

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf (B Group). 29.1162 Section 29.1162 Agriculture... INSPECTION Standards Grades § 29.1162 Leaf (B Group). This group consists of leaves normally grown at or above the midportion of the stalk. Leaves of the B group have a pointed tip, tend to fold, usually are...

[Morphological characteristics and physiological properties of aflatoxin B1 producing and non-producing Aspergillus flavus strains].

Science.gov (United States)

Kogbo, W; Lemarinier, S; Boutibonnes, P

1985-09-01

Comparison between about 80 strains of Aspergillus flavus, belonging to the series flavus and oryzae, obtained from international collections but also isolated from French or African substrates revealed the following observations: 1. Cultural and morphological characteristics of toxicogenic and atoxicogenic strains of A. flavus are similar. However, the former produce a diffusible yellow pigment in 83% of isolates. 2. The two groups of conidiospores have the same resistance to UV irradiation (254 nm, 5 and 10 min). All the strains are equally sensitive to 4 antifungal antibiotics: nystatine, ketoconazole, clotrimazole and amphotericine. 3. A difference was seen in the capacity to produce enzymes as alpha-galactosidase, beta-galactosidase and beta-glucosidase, implicated in the glucid metabolism. The specific hydrolytic activity has been confirmed by the characterization of a large amount of beta-galactosidase and by a diauxic growth on glucose medium supplemented by lactose. Possible relationship between these characters and aflatoxin B1 production by A. flavus strains is discussed.

The genome sequence of Brucella pinnipedialis B2/94 sheds light on the evolutionary history of the genus Brucella

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Claverie Jean-Michel

2011-07-01

Full Text Available Abstract Background Since the discovery of the Malta fever agent, Brucella melitensis, in the 19th century, six terrestrial mammal-associated Brucella species were recognized over the next century. More recently the number of novel Brucella species has increased and among them, isolation of species B. pinnipedialis and B. ceti from marine mammals raised many questions about their origin as well as on the evolutionary history of the whole genus. Results We report here on the first complete genome sequence of a Brucella strain isolated from marine mammals, Brucella pinnipedialis strain B2/94. A whole gene-based phylogenetic analysis shows that five main groups of host-associated Brucella species rapidly diverged from a likely free-living ancestor close to the recently isolated B. microti. However, this tree lacks the resolution required to resolve the order of divergence of those groups. Comparative analyses focusing on a genome segments unshared between B. microti and B. pinnipedialis, b gene deletion/fusion events and c positions and numbers of Brucella specific IS711 elements in the available Brucella genomes provided enough information to propose a branching order for those five groups. Conclusions In this study, it appears that the closest relatives of marine mammal Brucella sp. are B. ovis and Brucella sp. NVSL 07-0026 isolated from a baboon, followed by B. melitensis and B. abortus strains, and finally the group consisting of B. suis strains, including B. canis and the group consisting of the single B. neotomae species. We were not able, however, to resolve the order of divergence of the two latter groups.

[Multilocus sequence-typing for characterization of Moscow strains of Haemophilus influenzae type b].

Science.gov (United States)

Platonov, A E; Mironov, K O; Iatsyshina, S B; Koroleva, I S; Platonova, O V; Gushchin, A E; Shipulin, G A

2003-01-01

Haemophilius influenzae, type b (Hib) bacteria, were genotyped by multilocus sequence typing (MLST) using 5 loci (adk, fucK, mdh, pgi, recA). 42 Moscow Hib strains (including 38 isolates form cerebrospinal fluid of children, who had purulent meningitis in 1999-2001, and 4 strains isolated from healthy carriers of Hib), as well as 2 strains from Yekaterinburg were studied. In MLST a strain is characterized, by alleles and their combinations (an allele profile) referred to also as sequence-type (ST). 9 Sts were identified within the Russian Hib bacteria: ST-1 was found in 25 strains (57%), ST-12 was found in 8 strains (18%), ST-11 was found in 4 strains (9%) and ST-15 was found in 2 strains (4.5%); all other STs strains (13, 14, 16, 17, 51) were found in isolated cases (2.3%). A comparison of allelic profiles and of nucleotide sequences showed that 93% of Russian isolates, i.e. strain with ST-1, 11, 12, 13, 15 and 17, belong to one and the same clonal complex. 2 isolates from Norway and Sweden from among 7 foreign Hib strains studied up to now can be described as belonging to the same clonal complex; 5 Hib strains were different from the Russian ones.

Complete genome sequence of the bioleaching bacterium Leptospirillum sp. group II strain CF-1.

Science.gov (United States)

Ferrer, Alonso; Bunk, Boyke; Spröer, Cathrin; Biedendieck, Rebekka; Valdés, Natalia; Jahn, Martina; Jahn, Dieter; Orellana, Omar; Levicán, Gloria

2016-03-20

We describe the complete genome sequence of Leptospirillum sp. group II strain CF-1, an acidophilic bioleaching bacterium isolated from an acid mine drainage (AMD). This work provides data to gain insights about adaptive response of Leptospirillum spp. to the extreme conditions of bioleaching environments. Copyright © 2016 Elsevier B.V. All rights reserved.

Methanobactin from Methylocystis sp. strain SB2 affects gene expression and methane monooxygenase activity in Methylosinus trichosporium OB3b.

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Farhan Ul-Haque, Muhammad; Kalidass, Bhagyalakshmi; Vorobev, Alexey; Baral, Bipin S; DiSpirito, Alan A; Semrau, Jeremy D

2015-04-01

Methanotrophs can express a cytoplasmic (soluble) methane monooxygenase (sMMO) or membrane-bound (particulate) methane monooxygenase (pMMO). Expression of these MMOs is strongly regulated by the availability of copper. Many methanotrophs have been found to synthesize a novel compound, methanobactin (Mb), that is responsible for the uptake of copper, and methanobactin produced by Methylosinus trichosporium OB3b plays a key role in controlling expression of MMO genes in this strain. As all known forms of methanobactin are structurally similar, it was hypothesized that methanobactin from one methanotroph may alter gene expression in another. When Methylosinus trichosporium OB3b was grown in the presence of 1 μM CuCl2, expression of mmoX, encoding a subunit of the hydroxylase component of sMMO, was very low. mmoX expression increased, however, when methanobactin from Methylocystis sp. strain SB2 (SB2-Mb) was added, as did whole-cell sMMO activity, but there was no significant change in the amount of copper associated with M. trichosporium OB3b. If M. trichosporium OB3b was grown in the absence of CuCl2, the mmoX expression level was high but decreased by several orders of magnitude if copper prebound to SB2-Mb (Cu-SB2-Mb) was added, and biomass-associated copper was increased. Exposure of Methylosinus trichosporium OB3b to SB2-Mb had no effect on expression of mbnA, encoding the polypeptide precursor of methanobactin in either the presence or absence of CuCl2. mbnA expression, however, was reduced when Cu-SB2-Mb was added in both the absence and presence of CuCl2. These data suggest that methanobactin acts as a general signaling molecule in methanotrophs and that methanobactin "piracy" may be commonplace. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

New Highly Sensitive Real-Time PCR Assay for HIV-2 Group A and Group B DNA Quantification.

Science.gov (United States)

Bertine, Mélanie; Gueudin, Marie; Mélard, Adeline; Damond, Florence; Descamps, Diane; Matheron, Sophie; Collin, Fidéline; Rouzioux, Christine; Plantier, Jean-Christophe; Avettand-Fenoel, Véronique

2017-09-01

HIV-2 infection is characterized by a very low replication rate in most cases and low progression. This necessitates an approach to patient monitoring that differs from that for HIV-1 infection. Here, a new highly specific and sensitive method for HIV-2 DNA quantification was developed. The new test is based on quantitative real-time PCR targeting the long terminal repeat (LTR) and gag regions and using an internal control. Analytical performance was determined in three laboratories, and clinical performance was determined on blood samples from 63 patients infected with HIV-2 group A ( n = 35) or group B ( n = 28). The specificity was 100%. The 95% limit of detection was three copies/PCR and the limit of quantification was six copies/PCR. The within-run coefficients of variation were between 1.03% at 3.78 log 10 copies/PCR and 27.02% at 0.78 log 10 copies/PCR. The between-run coefficient of variation was 5.10%. Both manual and automated nucleic acid extraction methods were validated. HIV-2 DNA loads were detectable in blood cells from all 63 patients. When HIV-2 DNA was quantifiable, median loads were significantly higher in antiretroviral-treated than in naive patients and were similar for groups A and B. HIV-2 DNA load was correlated with HIV-2 RNA load ( r = 0.68; 95% confidence interval [CI], 0.4 to 0.8; P < 0.0001). Our data show that this new assay is highly sensitive and quantifies the two main HIV-2 groups, making it useful for the diagnosis of HIV-2 infection and for pathogenesis studies on HIV-2 reservoirs. Copyright © 2017 American Society for Microbiology.

[Vitamin B12-independent strains of Methylophaga marina isolated from Red Sea algae].

Science.gov (United States)

Li, Ts D; Doronina, N V; Ivanova, E G; Trotsenko, Iu A

2007-01-01

Two strains (KM3 and KM5) of halophilic methylobacteria isolated from Red Sea algae do not require vitamin B12 for growth and can use methanol, methylamine, dimethylamine, trimethylamine, dimethyl sulfide, and fructose as sources of carbon and energy. The cells of these strains are gram-negative motile monotrichous (strain KM3) or peritrichous (strain KM5) rods. The strains are strictly aerobic and require Na+ ions but not growth factors for growth. They are oxidase- and catalase-positive and reduce nitrates to nitrites. Both strains can grow in a temperature range of 4 to 37 degrees C (with optimal growth at 29-34 degrees C), at pH between 5.5 and 8.5 (with optimal growth at pH 7.5-8.0), and in a range of salt concentrations between 0.5 and 15% NaCl (with optimal growth at 5-9% NaCl). The phospholipids of these strains are dominated by phosphatidylethanolamine and phosphatidylglycerol and also include phosphatidylcholine, phosphatidylserine, and cardiolipin. The dominant fatty acids are C(16:1omega7c) and C(16:0). The major ubiquinone is Q8. The cells accumulate ectoin, glutamate, and sucrose as intracellular osmoprotectants. The strains implement the 2-keto-3-deoxy-6-phosphogluconate-dependent variant of the ribulose monophosphate pathway. The G+C content of the DNA is 44.4-44.7 mol %. Analysis of the 16S rRNA genes showed that both strains belong to Gammaproteobacteria and have a high degree of homology (99.4%) to Methylophaga marina ATCC 35842T . Based on the data of polyphasic taxonomy, strains KM3 and KM5 are identified as new strains M. marina KM3 (VKM B-2386) and M. marina KM5 (VKM B-2387). The ability of these strains to produce auxins (indole-3-acetic acid) suggests their metabolic association with marine algae.

Vaccination of dogs with canine parvovirus type 2b (CPV-2b) induces neutralising antibody responses to CPV-2a and CPV-2c.

Science.gov (United States)

Wilson, Stephen; Illambas, Joanna; Siedek, Elisabeth; Stirling, Catrina; Thomas, Anne; Plevová, Edita; Sture, Gordon; Salt, Jeremy

2014-09-22

Since the identification of canine parvovirus type 2, three variants have subsequently been observed differing from the historical CPV-2 and each other by 1-2 amino acids only. As a result there has been considerable research into differential diagnostics, with some researchers indicating there is a need for new vaccines containing different strains of CPV-2. In this study we investigated whether vaccination with a CPV-2b containing vaccine would induce cross-reactive antibody responses to the other CPV-2 variants. Two studies where dogs were vaccinated with a multivalent vaccine, subsequently challenged with CPV-2b and sera samples analysed are presented. Six week old pups with defined serological status were vaccinated twice, three weeks apart and challenged either 5 weeks (MDA override study) or one year after vaccination (duration of immunity study). Sera samples were collected before each vaccination and at periods throughout each study. In each study the antibody profiles were very similar; serological responses against CPV-2a, CPV-2b and CPV-2c were higher than those for CPV-2. Nevertheless, responses against CPV-2 were well above levels considered clinically protective. In each study dogs also showed a rapid increase in antibody titres following vaccination, reached a plateau following second vaccination with a slight decline to challenge after which rapid anamnestic responses were seen. Evaluation of the serological responses suggests vaccination with CPV-2b would cross-protect against CPV-2a and CPV-2c, as well as against CPV-2 which is now extinct in the field. In conclusion we have demonstrated that vaccination of minimum aged dogs with a multivalent vaccine containing the CPV-2b variant strain will induce serological responses which are cross-reactive against all currently circulating field strains, CPV-2a and CPV-2c, and the now extinct field strain CPV-2. Copyright © 2014 Elsevier Ltd. All rights reserved.

Comparison analysis of microRNAs in response to dengue virus type 2 infection between the Vero cell-adapted strain and its source, the clinical C6/36 isolated strain.

Science.gov (United States)

Yang, Jiajia; Lin, Yao; Jiang, Liming; Xi, Juemin; Wang, Xiaodan; Guan, Jiaoqiong; Chen, Junying; Pan, Yue; Luo, Jia; Ye, Chao; Sun, Qiangming

2018-05-02

To elucidate the differences in microRNAs during dengue virus infection between Vero cell-adapted strain (DENV-2-Vero) and its source, the clinical C6/36 isolated strain (DENV-2-C6/36), a comparison analysis was performed in Vero cells by high throughput sequencing. The results showed that the expression of 16 known and 3 novel miRNAs exhibited marked differences. 5 known miRNAs were up-regulated in DENV-2-C6/36 group, while 11 known microRNAs were down-regulated in DENV-2-Vero group. The GO enrichment and KEGG pathway analysis showed that there was a distinct difference in regulating viral replication between two strains. In DENV-2-Vero infection group, significantly enriched GO terms included virion attachment to host cells, viral structural protein/genome processing and packaging. Meanwhile, the regulation of cell death and apoptosis between two groups were different in the early stage of infection. KEGG enrichment analysis showed that DENV-2-C6/36 infection induced more intense regulation of immune-related pathways, including Fc gamma R-mediated phagocytosis, etc. DENV-2-Vero infection could partially alleviate the immune defense of Vero cells compared with DENV-2-C6/36. The results indicated that the distinct microRNA changes induced by two DENV-2 strains may be partly related to their infective abilities. Our data provide useful insights that help elucidate the host-pathogen interactions following DENV infection. Copyright © 2018 Elsevier B.V. All rights reserved.

An oxygen dependent X-ray lesion in Escherichia coli strain B/r detected by penicillin

International Nuclear Information System (INIS)

Gillies, N.E.; Obioha, F.I.; Ratnajothi, N.H.

1979-01-01

Enhancement of lethal damage to E. coli B/r by penicillin was observed after X-irradiation under aerobic conditions, but not after exposure to X-rays under anoxia or after U.V. (260 nm) irradiation. No enhancement of damage occurred when incubation with penicillin was delayed for 2 hours after aerobic X-irradiation. This enhancing effect was only detected in this strain and not in the filamentous strain E. coli B. It was concluded that an X-ray induced lesion, sensitive to the presence of oxygen at the time of irradiation and probably located in the cell envelope, initiates filamentation in E. coli B/r, which results in lethal damage in this strain. (author)

A large portion of meningococcal antigen typing system-negative meningococcal strains from spain is killed by sera from adolescents and infants immunized with 4CMenB.

Science.gov (United States)

Abad, R; Biolchi, A; Moschioni, M; Giuliani, M M; Pizza, M; Vázquez, J A

2015-04-01

A new vaccine (the 4CMenB 4-component protein vaccine [Bexsero], which includes PorA, factor H-binding protein [fHbp], neisserial heparin-binding antigen [NHBA], and Neisseria adhesin A [NadA]) against serogroup B meningococci has recently been approved for use in people older than age 2 months in Europe, Australia, and Canada. Preapproval clinical efficacy studies are not feasible for invasive meningococcal disease because its incidence is low/very low, and the serum bactericidal antibody (SBA) titer (or the human SBA [hSBA] titer when human complement is used in the assay) has been used as a surrogate marker of protection. However, the hSBA assay cannot be used on a large scale, and therefore, a meningococcal antigen typing system (MATS) was developed. MATS combines conventional PorA genotyping with an enzyme-linked immunosorbent assay (ELISA) that quantifies both the expression and the cross-reactivity of antigenic variants. The assay has been used to evaluate the potential of the 4CMenB meningococcal group B vaccine to cover group B strains in several countries. Some recent data suggest that MATS is a conservative predictor of strain coverage. We used pooled sera from adolescents and infants to test by the hSBA assay 10 meningococcal group B strains isolated in Spain that were negative for the 3 antigens (n = 9) or that had very low levels of the 3 antigens (n = 1) by MATS. We found that all strains were killed by sera from adolescents and that 5 of the 10 strains were also killed, although at a low titer, by sera from infants. Our data confirm that MATS underestimates vaccine coverage. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Immunogenicity, reactogenicity, and safety of a P1.7b,4 strain-specific serogroup B meningococcal vaccine given to preteens.

Science.gov (United States)

Hosking, Jamie; Rasanathan, Kumanan; Mow, Florina Chan; Jackson, Catherine; Martin, Diana; O'Hallahan, Jane; Oster, Philipp; Ypma, Ellen; Reid, Stewart; Aaberge, Ingeborg; Crengle, Sue; Stewart, Joanna; Lennon, Diana

2007-11-01

New Zealand (NZ) has experienced a Neisseria meningitidis serogroup B epidemic since 1991. MeNZB, a strain-specific outer membrane vesicle vaccine made using an NZ epidemic strain isolate, NZ98/254 (B:4:P1.7b,4), from two manufacturing sites, the Norwegian Institute of Public Health (NIPH) and Chiron Vaccines (CV; now Novartis), was evaluated for safety, immunogenicity, and reactogenicity in this observer-blind trial with 8- to 12-year-old children. In year 1, cohort A (n = 302) was randomized 4:1 for receipt of NIPH-MeNZB or MenBvac (Norwegian parent vaccine strain 44/76; B:15:P1.7,16). In year 2, cohort B (n = 313) was randomized 4:1 for receipt of CV-MeNZB or NIPH-MeNZB. Participants all received three vaccinations 6 weeks apart. Local and systemic reactions were monitored for 7 days. Seroresponse was defined as a fourfold or greater rise in the serum bactericidal antibody titer from the baseline titer as measured by a serum bactericidal assay. Those with baseline titers of /=1:8 to serorespond. Intention-to-treat (ITT) and per protocol (PP) analyses are presented. In cohort A, 74% (ITT) and 73% (PP) of NIPH-MeNZB recipients demonstrated seroresponses against NZ98/254 after three doses, versus 32% (ITT and PP) of MenBvac recipients. In cohort B, seroresponses against NZ98/254 after three doses occurred in 79% (ITT and PP) of CV-MeNZB versus 75% (ITT) and 76% (PP) of NIPH-MeNZB recipients. Vaccines were tolerable, with no vaccine-related serious adverse events. In conclusion, the NZ strain meningococcal B vaccine (MeNZB) from either manufacturing site was immunogenic against New Zealand epidemic vaccine strain meningococci with no safety concerns when given in three doses to these 8- to 12-year-old children.

Slow Epidemic of Lymphogranuloma Venereum L2b Strain

Science.gov (United States)

Spaargaren, Joke; Schachter, Julius; Moncada, Jeanne; de Vries, Henry J.C.; Fennema, Han S.A.; Peña, A. Salvador; Coutinho, Roel A.

2005-01-01

We traced the Chlamydia trachomatis L2b variant in Amsterdam and San Francisco. All recent lymphogranuloma venereum cases in Amsterdam were caused by the L2b variant. This variant was also present in the 1980s in San Francisco. Thus, the current "outbreak" is most likely a slowly evolving epidemic. PMID:16318741

Development of a genetic sexing strain in Bactrocera carambolae (Diptera: Tephritidae) by introgression of sex sorting components from B. dorsalis, Salaya1 strain.

Science.gov (United States)

Isasawin, Siriwan; Aketarawong, Nidchaya; Lertsiri, Sittiwat; Thanaphum, Sujinda

2014-01-01

The carambola fruit fly, Bactrocera carambolae Drew & Hancock is a high profile key pest that is widely distributed in the southwestern ASEAN region. In addition, it has trans-continentally invaded Suriname, where it has been expanding east and southward since 1975. This fruit fly belongs to Bactrocera dorsalis species complex. The development and application of a genetic sexing strain (Salaya1) of B. dorsalis sensu stricto (s.s.) (Hendel) for the sterile insect technique (SIT) has improved the fruit fly control. However, matings between B. dorsalis s.s. and B. carambolae are incompatible, which hinder the application of the Salaya1 strain to control the carambola fruit fly. To solve this problem, we introduced genetic sexing components from the Salaya1 strain into the B. carambolae genome by interspecific hybridization. Morphological characteristics, mating competitiveness, male pheromone profiles, and genetic relationships revealed consistencies that helped to distinguish Salaya1 and B. carambolae strains. A Y-autosome translocation linking the dominant wild-type allele of white pupae gene and a free autosome carrying a recessive white pupae homologue from the Salaya1 strain were introgressed into the gene pool of B. carambolae. A panel of Y-pseudo-linked microsatellite loci of the Salaya1 strain served as markers for the introgression experiments. This resulted in a newly derived genetic sexing strain called Salaya5, with morphological characteristics corresponding to B. carambolae. The rectal gland pheromone profile of Salaya5 males also contained a distinctive component of B. carambolae. Microsatellite DNA analyses confirmed the close genetic relationships between the Salaya5 strain and wild B. carambolae populations. Further experiments showed that the sterile males of Salaya5 can compete with wild males for mating with wild females in field cage conditions. Introgression of sex sorting components from the Salaya1 strain to a closely related B. carambolae

Detergents enhance EspB secretion from Escherichia coli strains harboring the locus for the enterocyte effacement (LEE) gene.

Science.gov (United States)

Nakasone, Noboru; Toma, Claudia; Higa, Naomi; Koizumi, Yukiko; Ogura, Yasunori; Suzuki, Toshihiko

2011-02-01

The effects of detergents (cholic acid, deoxycholic acid, Triton X-100, and Nonidet P-40) on the secretion of EspB from the locus for enterocyte effacement (LEE) gene-positive Escherichia coli strains were examined. Clinical isolates of eight EPEC strains and seven STEC strains were used to detect EspB after they had been cultivated in Luria-Bertani (LB) broth containing one of the detergents. When the bacteria were cultured in LB broth supplemented with one of the detergents, the amount of EspB produced was increased by 2-32-fold depending on the detergent and the strain used. EspB was detected in all strains when they were cultured in LB broth containing all of the detergents. The results obtained in this study can be applied to immunological diagnostic methods for detecting EspB and also to the production of EspB for research purposes. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

The possibility of discriminating within the Bacillus cereus group using gyrB sequencing and PCR-RFLP

DEFF Research Database (Denmark)

Jensen, Gert B; Fisker, Niels; Sparsø, Thomas

2005-01-01

Based on a combination of PCR and restriction endonuclease (RE) digestion (PCR-RE digestion), we have examined the possibility of differentiating members of the Bacillus cereus group. Fragments of the gyrB gene (362 bp) from pure cultures of 12 B. cereus, 25 B. thuringiensis, 25 B. mycoides and two......, it was not possible to discriminate between the B. cereus and the B. thuringiensis strains using the methods described....

Identification of Lactobacillus UFV H2b20 (probiotic strain using DNA-DNA hybridization Identificação de Lactobacillus UFV H2b20 (linhagem probiótica através de hibridização DNA-DNA

Directory of Open Access Journals (Sweden)

J.T. de Magalhães

2008-09-01

Full Text Available Sequence analyses of the 16S rDNA gene and DNA-DNA hybridization tests were performed for identification of the species of the probiotic Lactobacillus UFV H2b20 strain. Using these two tests, we concluded that this strain, originally considered Lact. acidophilus, should be classified as Lact. delbrueckii.Análise da seqüência do gene 16S rDNA e ensaios de hibridização DNA_DNA foram empregados para identificar a espécie da cepa probiótica Lactobacillus UFV H2b20. Empregando-se estes dois testes, concluímos que esta cepa, originalmente considerada Lact. acidophilus, deve ser classificada como Lact. delbrueckii.

Group B Streptococcus and Pregnancy

Science.gov (United States)

... B Strep and Pregnancy • What is group B streptococcus (GBS)? • What does it mean to be colonized ... planned cesarean birth? •Glossary What is group B streptococcus (GBS)? Group B streptococcus is one of the ...

Feeding activity in Groups of Newly Hatched Broiler Chicks: Effects of strain and hatching time

DEFF Research Database (Denmark)

Nielsen, Birte Lindstrøm; Juul-Madsen, Helle Risdahl; Steenfeldt, Sanna

2010-01-01

The feeding activity of 2 strains of broiler chickens was investigated during their first week of life in relation to their hatching time. Fast (Ross 308) and slow-growing (LB) strains were allocated to 1 of 3 (early, middle, or late hatch) single-strain groups of 80 to 100 as-hatched birds in 4...

Co-Circulation of the Rare CPV-2c with Unique Gln370Arg Substitution, New CPV-2b with Unique Thr440Ala Substitution, and New CPV-2a with High Prevalence and Variation in Heilongjiang Province, Northeast China.

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Yufei Geng

Full Text Available To trace evolution of canine parvovirus-2 (CPV-2, a total of 201 stool samples were collected from dogs with diarrhea in Heilongjiang province of northeast China from May 2014 to April 2015. The presence of CPV-2 in the samples was determined by PCR amplification of the VP2 gene (568 bp of CPV-2. The results revealed that 95 samples (47.26% were positive for CPV-2, and they showed 98.8%-100% nucleotide identity and 97.6%-100% amino acid identity. Of 95 CPV-2-positive samples, types new2a (Ser297Ala, new2b (Ser297Ala, and 2c accounted for 64.21%, 21.05%, and 14.74%, respectively. The positive rate of CPV-2 and the distribution of the new2a, new2b and 2c types exhibited differences among regions, seasons, and ages. Immunized dogs accounted for 48.42% of 95 CPV-2-positive samples. Coinfections with canine coronavirus, canine kobuvirus, and canine bocavirus were identified. Phylogenetic analysis revealed that the identified new2a, new2b, and CPV-2c strains in our study exhibited a close relationship with most of the CPV-2 strains from China; type new2a strains exhibited high variability, forming three subgroups; type new2b and CPV-2c strains formed one group with reference strains from China. Of 95 CPV-2 strains, Tyr324Ile and Thr440Ala substitutions accounted for 100% and 64.21%, respectively; all type new2b strains exhibited the Thr440Ala substitution, while the unique Gln370Arg substitution was found in all type 2c strains. Recombination analysis using entire VP2 gene indicated possible recombination events between the identified CPV-2 strains and reference strains from China. Our data revealed the co-circulation of new CPV-2a, new CPV-2b, and rare CPV-2c, as well as potential recombination events among Chinese CPV-2 strains.

Nodulation and N2 fixation effectiveness of Bradyrhizobium strains in symbiosis with Adzuki Bean, Vigna angularis

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Dušica Delić

2010-04-01

Full Text Available In pot experiment, one isolate Knj from a Serbian soil, four strains of Bradyrhizobium japonicum and three strains of Bradyrhizobium spp. were examined for the effect on adzuki bean nodulation and effectiveness in symbiotic N2 fixation. All the tested strains produced root nodules in adzuki bean. Strains of B. japonicum showed high potential of N2 fixation, particularly 525 and 542. B. japonicum strains resulted 65-71% shoot dry weight and 99-138% total N content of uninoculated control with full N content (100%. No significant difference was found between the plants inoculated with Bradyrhizobium spp. strains and uninoculated control plants without N (40-42 and 42% shoot dry weight, respectively, which indicated symbiotic N2 fixation inactivity of the Bradyrhizobium spp. strains. Knj strain had the middle position (56% shoot dry weight. These data showed that B. japonicum 525 and 542 strains could be used in further investigations in order to apply them as inoculants in microbiological N fertilizers.

Ultraviolet radiation-induced mutability of isogenic uvrA and uvrB strains of Escherichia coli K-12 W3110

International Nuclear Information System (INIS)

Barfknecht, T.R.; Smith, K.C.

1977-01-01

E. coli K-12 W3110 uvrB5 strain has been shown to have a higher UV induced reversion frequency than its wild-type parent when plotted on the basis of mutation frequency versus survival. However for the E. coli B/r WP2s uvrA strain this higher mutability has been observed only at survival levels of 80-100%. A study was undertaken to determine if these differences in UV mutability were due primarily to the uvrA and uvrB mutations, or to other genetic background differences. Isogenic strains of E. coli K-12 W3110 carrying uvrA6, uvrB5, uvrA6 and uvrB5, and the uvrA allele from E.coli B/r WP2s were used. Results indicate that the enrichment of minimal medium with a small amount of nutrient broth is sufficient to inhibit minimal medium recovery (MMR) and to enhance leu + reversion of the leu B missense mutation in these uvr - strains. This suggests that there may be a relationship between MMR and error-free postreplication repair. Further research is in progress to clarify the relationship between MMR and broth enhancement of UV-induced mutagenesis in uvr - strains of E. Coli K-12 W3110. (author)

Ultraviolet radiation-induced mutability of isogenic uvrA and uvrB strains of Escherichia coli K-12 W3110

Energy Technology Data Exchange (ETDEWEB)

Barfknecht, T R; Smith, K C [Stanford Univ., Calif. (USA). Dept. of Radiology

1977-12-01

Escherichia coli K-12 W3110 uvrB5 strain has been shown to have a higher uv-induced reversion frequency than its wild-type parent when plotted on the basis of mutation frequency versus survival. However for the E. coli B/r WP2s uvrA strain this higher mutability has been observed only at survival levels of 80 to 100%. A study was undertaken to determine if ly to the uvrA and uvrB mutations, or to other genetic background differences. Isogenic strains of E. coli K-12 W3110 carrying uvrA6, uvrB5, uvrA6, and uvrB5, and the uvrA allele from E.coli B/r WP2s were used. Results indicate that the enrichment of minimal medium with a small amount of nutrient broth is sufficient to inhibit minimal medium recovery (MMR) and to enhance leu/sup +/ reversion of the leu B missense mutation in these uvr/sup -/ strains. This suggests that there may be a relationship between MMR and error-free postreplication repair. Further research is in progress to clarify the relationship between MMR and broth enhancement of uv-induced mutagenesis in uvr/sup -/ strains of E. Coli K-12 W3110.

Group B streptococcus - pregnancy

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... medlineplus.gov/ency/patientinstructions/000511.htm Group B streptococcus - pregnancy To use the sharing features on this page, please enable JavaScript. Group B streptococcus (GBS) is a type of bacteria that some ...

Genetic analysis of the VP2-encoding gene of canine parvovirus strains from Africa.

Science.gov (United States)

Dogonyaro, Banenat B; Bosman, Anna-Mari; Sibeko, Kgomotso P; Venter, Estelle H; van Vuuren, Moritz

2013-08-30

Since the emergence of canine parvovirus type-2 (CPV-2) in the early 1970s, it has been evolving into novel genetic and antigenic variants (CPV-2a, 2b and 2c) that are unevenly distributed throughout the world. Genetic characterization of CPV-2 has not been documented in Africa since 1998 apart from the study carried out in Tunisia 2009. A total of 139 field samples were collected from South Africa and Nigeria, detected using PCR and the full length VP2-encoding gene of 27 positive samples were sequenced and genetically analyzed. Nigerian samples (n=6), South Africa (n=19) and vaccine strains (n=2) were compared with existing sequences obtained from GenBank. The results showed the presence of both CPV-2a and 2b in South Africa and only CPV-2a in Nigeria. No CPV-2c strain was detected during this study. Phylogenetic analysis showed a clustering not strictly associated with the geographical origin of the analyzed strains, although most of the South African strains tended to cluster together and the viral strains analyzed in this study were not completely distinct from CPV-2 strains from other parts of the world. Amino acid analysis showed predicted amino acid changes. Copyright © 2013 Elsevier B.V. All rights reserved.

Linkage of genes for laminin B1 and B2 subunits on chromosome 1 in mouse.

Science.gov (United States)

Elliott, R W; Barlow, D; Hogan, B L

1985-08-01

We have used cDNA clones for the B1 and B2 subunits of laminin to find restriction fragment length DNA polymorphisms for the genes encoding these polypeptides in the mouse. Three alleles were found for LamB2 and two for LamB1 among the inbred mouse strains. The segregation of these polymorphisms among recombinant inbred strains showed that these genes are tightly linked in the central region of mouse Chromosome 1 between Sas-1 and Ly-m22, 7.4 +/- 3.2 cM distal to the Pep-3 locus. There is no evidence in the mouse for pseudogenes for these proteins.

7 CFR 29.2662 - Heavy Leaf (B Group).

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Heavy Leaf (B Group). 29.2662 Section 29.2662 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.2662 Heavy Leaf (B Group). This group consists of leaves...

Diversification of the vacAs1m1 and vacAs2m2 strains of Helicobacter pylori in Meriones unguiculatus

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Sandra Mendoza Elizalde

2016-11-01

Full Text Available The bacterium Helicobacter pylori exhibits great genetic diversity, and the pathogenic roles of its virulence factors have been widely studied. However, the evolutionary dynamics of H. pylori strains during stomach colonization are not well characterized. Here, we analyzed the microevolutionary dynamics of the toxigenic strain vacAs1m1, the non-toxigenic strain vacAs2m2, and a combination of both strains in an animal model over time. Meriones unguiculatus were inoculated with the following bacteria: group 1–toxigenic strain vacAs1m1/cagA+/cagE+/babA2+; ST181, group 2–non-toxigenic strain vacAs2m2/ cagA+/ cagE+/ babA2+; ST2901, and group 3–both strains. The gerbils were euthanized at different time points (3, 6, 12 and 18 months. In group 1, genetic alterations were observed at 6 and 12 months. With the combination of both strains, group 3 also exhibited genetic alterations at 3 and 18 months; moreover, a chimera, vacA m1-m2, was detected. Additionally, four new sequence types (STs were reported in the PubMLST database for H. pylori. Synonymous and non-synonymous mutations were analyzed and associated with alterations in amino acids. Microevolutionary analysis of the STs (PHYLOViZ identified in each group revealed many mutational changes in the toxigenic (vacAs1m1 and non-toxigenic (vacAs2m2 strains. Phylogenetic assessments (eBURST did not reveal clonal complexes. Our findings indicate that the toxigenic strain, vacAs1m1, and a combination of toxigenic and non-toxigenic strains acquired genetic material by recombination. The allelic combination, vacAs2m1, displayed the best adaptation in the animal model over time, and a chimera, m1-m2, was also identified, which confirmed previous reports.

Typing discrepancy between phenotypic and molecular characterization revealing an emerging biovar 9 variant of smooth phage-resistant B. abortus strain 8416 in China

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YaoXia eKang

2015-12-01

Full Text Available A newly isolated smooth colony morphology phage-resistant (SPR strain 8416 isolated from a 45-year-old cattle farm cleaner with clinical features of brucellosis in China was reported. The most unusual phenotype was its resistance to two Brucella phages Tbilisi and Weybridge, but sensitive to Berkeley 2, a pattern similar to that of B. melitensis biovar 1. VITEK 2 biochemical identification system found that both strain 8416 and B. melitensis strains shared positive ILATk, but negative in other B. abortus strains. However, routine biochemical and phenotypic characteristics of strain 8416 were most similar to that of B. abortus biovar 9 except CO2 requirement. In addition, multiple PCR molecular typing assays including AMOS-PCR, B. abortus special PCR (B-ab PCR and a novel sub-biovar typing PCR, indicated that strain 8416 may belong to either biovar 3b or 9 of B. abortus. Surprisingly, further MLVA typing results showed that strain 8416 was most closely related to B. abortus biovar 3 in the Brucella MLVA database, primarily differing in 4 out of 16 screened loci. Therefore, due to the unusual discrepancy between phenotypic (biochemical reactions and particular phage lysis profile and molecular typing characteristics, strain 8416 couldn’t be exactly classified to any of the existing B. abortus biovars and might be a new variant of B. abortus biovar 9. The present study also indicates that the present phage typing scheme for Brucella spp. is subject to variation and the routine Brucella biovar typing needs further studies.

7 CFR 29.2437 - Heavy Leaf (B Group).

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Heavy Leaf (B Group). 29.2437 Section 29.2437... REGULATIONS TOBACCO INSPECTION Standards Grades § 29.2437 Heavy Leaf (B Group). This group consists of leaves..., are heavier in body than those of the X or C groups, and show no ground injury. Choice- and fine...

Fumonisin and Ochratoxin Production in Industrial Aspergillus niger Strains

DEFF Research Database (Denmark)

Frisvad, Jens Christian; Larsen, Thomas Ostenfeld; Thrane, Ulf

2011-01-01

as safe). However, A. niger has the potential to produce two groups of potentially carcinogenic mycotoxins: fumonisins and ochratoxins. In this study all available industrial and many non-industrial strains of A. niger (180 strains) as well as 228 strains from 17 related black Aspergillus species were...... examined for mycotoxin production. None of the related 17 species of black Aspergilli produced fumonisins. Fumonisins (B(2), B(4), and B(6)) were detected in 81% of A. niger, and ochratoxin A in 17%, while 10% of the strains produced both mycotoxins. Among the industrial strains the same ratios were 83......%, 33% and 26% respectively. Some of the most frequently used strains in industry NRRL 337, 3112 and 3122 produced both toxins and several strains used for citric acid production were among the best producers of fumonisins in pure agar culture. Most strains used for other biotechnological processes also...

Novel high pressure hexagonal OsB2 by mechanochemistry

Science.gov (United States)

Xie, Zhilin; Graule, Moritz; Orlovskaya, Nina; Andrew Payzant, E.; Cullen, David A.; Blair, Richard G.

2014-07-01

Hexagonal OsB2, a theoretically predicted high-pressure phase, has been synthesized for the first time by a mechanochemical method, i.e., high energy ball milling. X-ray diffraction indicated that formation of hexagonal OsB2 begins after 2.5 h of milling, and the reaction reaches equilibrium after 18 h of milling. Rietveld refinement of the powder data indicated that hexagonal OsB2 crystallizes in the P63/mmc space group (No. 194) with lattice parameters of a=2.916 Å and c=7.376 Å. Transmission electron microscopy confirmed the appearance of the hexagonal OsB2 phase after high energy ball milling. in situ X-ray diffraction experiments showed that the phase is stable from -225 °C to 1050 °C. The hexagonal OsB2 powder was annealed at 1050 °C for 6 days in vacuo to improve crystallinity and remove strain induced during the mechanochemical synthesis. The structure partially converted to the orthorhombic phase (20 wt%) after fast current assisted sintering of hexagonal OsB2 at 1500 °C for 5 min. Mechanochemical approaches to the synthesis of hard boride materials allow new phases to be produced that cannot be prepared using conventional methods.

Construction of the irreducibles of B(2, 2)

International Nuclear Information System (INIS)

Melas, Evangelos

2006-01-01

The ordinary Bondi-Metzner-Sachs (BMS) group B is the common asymptotic symmetry group of all radiating, asymptotically flat, Lorentzian spacetimes. As such, B is the best candidate for the universal symmetry group of general relativity. However, in studying quantum gravity, spacetimes with signatures other than the usual Lorentzian one and complex spacetimes are frequently considered. Generalizations of B appropriate to these other signatures have been defined earlier. In particular, the generalization B(2, 2) appropriate to the ultrahyperbolic signature (+, +, -, -) has been described in detail, and the study of its irreducible unitary representations (IRs) of B(2, 2) has been initiated. The infinite little groups have been given explicitly, but the finite little groups have only been partially described. This study is completed by describing in detail the finite little groups and by giving all the necessary information in order to construct the IRs of B(2, 2) in all cases

Effects of UV-B radiation on microcystin production of a toxic strain of Microcystis aeruginosa and its competitiveness against a non-toxic strain

International Nuclear Information System (INIS)

Yang, Zhen; Kong, Fanxiang; Shi, Xiaoli; Yu, Yang; Zhang, Min

2015-01-01

Highlights: • UV-B radiation showed higher inhibition to non-toxin producing than toxin-producing strains on growth and photosynthetic activity. • Both intracellular and extracellular MC contents decreased markedly under UV-B radiation. • Higher resistance to UV-B radiation helped toxin-producing M. aeruginosa to predominate in the competition. - Abstract: Microcystins (MCs) produced by toxic cyanobacteria pose a health hazard to humans and animals. Some environmental factors can alter the MC concentrations by affecting the abundance of toxin-producing strains in a cyanobacteria population and/or their toxin production. In this study, we designed a monoculture and competition experiment to investigate the impacts of UV-B radiation on MC production and the competition between toxin and non-toxin producing strains of Microcystis aeruginosa. UV-B radiation resulted in higher inhibition of the growth and photosynthetic activity of the non-toxin producing strain relative to that observed for the toxin-producing strain. Both intracellular and extracellular MC contents decreased markedly when the toxin-producing strain was exposed to UV-B radiation. In addition, a quantitative real-time PCR assay revealed that the ratio of toxin-producing M. aeruginosa under UV-B exposure was higher than that under PAR alone at an early stage of the experiment. However, its abundance under UV-B exposure was lower compared with the PAR alone treatment after day 12. Our study demonstrated that UV-B radiation has a great impact on the abundance of the toxin-producing strain in the Microcystis population and their toxin production, which suggests that the fluctuation of UV-B radiation affects the MC level of cyanobacteria blooms

Effects of UV-B radiation on microcystin production of a toxic strain of Microcystis aeruginosa and its competitiveness against a non-toxic strain

Energy Technology Data Exchange (ETDEWEB)

Yang, Zhen, E-mail: zhyang@niglas.ac.cn; Kong, Fanxiang, E-mail: fxkong@niglas.ac.cn; Shi, Xiaoli; Yu, Yang; Zhang, Min

2015-02-11

Highlights: • UV-B radiation showed higher inhibition to non-toxin producing than toxin-producing strains on growth and photosynthetic activity. • Both intracellular and extracellular MC contents decreased markedly under UV-B radiation. • Higher resistance to UV-B radiation helped toxin-producing M. aeruginosa to predominate in the competition. - Abstract: Microcystins (MCs) produced by toxic cyanobacteria pose a health hazard to humans and animals. Some environmental factors can alter the MC concentrations by affecting the abundance of toxin-producing strains in a cyanobacteria population and/or their toxin production. In this study, we designed a monoculture and competition experiment to investigate the impacts of UV-B radiation on MC production and the competition between toxin and non-toxin producing strains of Microcystis aeruginosa. UV-B radiation resulted in higher inhibition of the growth and photosynthetic activity of the non-toxin producing strain relative to that observed for the toxin-producing strain. Both intracellular and extracellular MC contents decreased markedly when the toxin-producing strain was exposed to UV-B radiation. In addition, a quantitative real-time PCR assay revealed that the ratio of toxin-producing M. aeruginosa under UV-B exposure was higher than that under PAR alone at an early stage of the experiment. However, its abundance under UV-B exposure was lower compared with the PAR alone treatment after day 12. Our study demonstrated that UV-B radiation has a great impact on the abundance of the toxin-producing strain in the Microcystis population and their toxin production, which suggests that the fluctuation of UV-B radiation affects the MC level of cyanobacteria blooms.

Typing Discrepancy Between Phenotypic and Molecular Characterization Revealing an Emerging Biovar 9 Variant of Smooth Phage-Resistant B. abortus Strain 8416 in China.

Science.gov (United States)

Kang, Yao-Xia; Li, Xu-Ming; Piao, Dong-Ri; Tian, Guo-Zhong; Jiang, Hai; Jia, En-Hou; Lin, Liang; Cui, Bu-Yun; Chang, Yung-Fu; Guo, Xiao-Kui; Zhu, Yong-Zhang

2015-01-01

A newly isolated smooth colony morphology phage-resistant strain 8416 isolated from a 45-year-old cattle farm cleaner with clinical features of brucellosis in China was reported. The most unusual phenotype was its resistance to two Brucella phages Tbilisi and Weybridge, but sensitive to Berkeley 2, a pattern similar to that of Brucella melitensis biovar 1. VITEK 2 biochemical identification system found that both strain 8416 and B. melitensis strains shared positive ILATk, but negative in other B. abortus strains. However, routine biochemical and phenotypic characteristics of strain 8416 were most similar to that of B. abortus biovar 9 except CO2 requirement. In addition, multiple PCR molecular typing assays including AMOS-PCR, B. abortus special PCR (B-ab PCR) and a novel sub-biovar typing PCR, indicated that strain 8416 may belong to either biovar 3b or 9 of B. abortus. Surprisingly, further MLVA typing results showed that strain 8416 was most closely related to B. abortus biovar 3 in the Brucella MLVA database, primarily differing in 4 out of 16 screened loci. Therefore, due to the unusual discrepancy between phenotypic (biochemical reactions and particular phage lysis profile) and molecular typing characteristics, strain 8416 could not be exactly classified to any of the existing B. abortus biovars and might be a new variant of B. abortus biovar 9. The present study also indicates that the present phage typing scheme for Brucella sp. is subject to variation and the routine Brucella biovar typing needs further studies.

Characterization of extracellular vitamin B12 producing Lactobacillus plantarum strains and assessment of the probiotic potentials.

Science.gov (United States)

Li, Ping; Gu, Qing; Yang, Lanlan; Yu, Yue; Wang, Yuejiao

2017-11-01

We investigated extracellular vitamin B 12 -producing Lactobacillus strains and their characteristics in tolerance to environmental stresses, gastric acid and bile salts. Two isolates, Lactobacillus plantarum LZ95 and CY2, showed high extracellular B 12 production, 98±15μg/L and 60±9μg/L respectively. Extracellular B 12 from LZ95 were identified as adenosylcobalamin and methylcobalamin using a combination of solid phase extraction and reverse-phase HPLC, while that from CY2 was adenosylcobalamin. Both strains grew under environmental stresses, and LZ95 exhibited better tolerance to low temperature and high ethanol concentration. LZ95 also showed good viability when exposed to gastric acid (pH 2.0 and 3.0) and bile salts (0.3%) as well as good adhesion to Caco-2 cells. The viability of CY2 was significantly reduced under low pH and exposure to bile salt. Together, extracellular B 12 producer LZ95 with good probiotic properties might be a candidate for in situ B 12 fortification in the food industry. Copyright © 2017 Elsevier Ltd. All rights reserved.

High level expression and characterization of the cyclophilin B gene from the anaerobic fungus Orpinomyces sp. strain PC-2.

Science.gov (United States)

Chen, Huizhong; Li, Xin-Liang; Xu, Haiyan; Ljungdahl, Lars G; Cerniglia, Carl E

2006-01-01

Cyclophilins are an evolutionarily conserved family of peptidyl-prolyl cis-trans isomerases (PPIases). A cyclophilin B (cypB) gene from the anaerobic fungus Orpinomyces sp. strain PC-2 was cloned and overexpressed in Escherichia coli. It was expressed as an amino-terminal 6 x His-tagged recombinant protein to facilitate purification. Highly purified protein (26.5 kDa) was isolated by two chromatographic steps involving affinity and gel filtration for biochemical studies of the enzyme. The recombinant CypB displayed PPIase activity with a k(cat)/K(m) of 8.9 x 10(6) M(-1) s(-1) at 10 degrees C and pH 7.8. It was inhibited by cyclosporin A (CsA) with an IC(50) of 23.5 nM, similar to those of the native protein and other cyclophilin B enzymes from animals. Genomic DNA analysis of cypB revealed that it was present as a single copy in Orpinomyces PC-2 and contained two introns, indicating it has a eukaryotic origin. It is one of the most heavily interrupted genes with intron sequences found in anaerobic fungi. The three-dimensional model of Orpinomyces PC-2 CypB was predicted with a homology modeling approach using the Swiss-Model Protein Modeling Server and three dimensional structure of human CypB as a template. The overall architecture of the CypB molecule is very similar to that of human CypB.

Effects of paraquat on Escherichia coli: Differences between B and K-12 strains

International Nuclear Information System (INIS)

Kitzler, J.W.; Minakami, H.; Fridovich, I.

1990-01-01

Escherichia coli B and K-12 are equally susceptible to the bacteriostatic effects of aerobic paraquat, but they differed strikingly when the lethality of paraquat was evaluated. E. coli B suffered an apparent loss of viability when briefly exposed to paraquat, whereas E. coli K-12 did not. This difference depended on the ability of the B-strain, but not the K-12 strain, to retain internalized paraquat; the B strain was killed on aerobic tryptic soy-yeast extract plates during the incubation which preceded the counting of colonies. This difference in retention of paraquat between strains was demonstrated by delayed loss of viability, by growth inhibition, and by cyanide-resistant respiration after brief exposure to paraquat, washing, and testing in fresh medium. This difference was also shown by using [ 14 C]paraquat. This previously unrecognized difference between E. coli B and K-12 has been the cause of apparently contradictory reports and should lead to some reevaluation of the pertinent literature

Short-period strain (0.1-105 s): Near-source strain field for an earthquake (M L 3.2) near San Juan Bautista, California

Science.gov (United States)

Johnston, M. J. S.; Borcherdt, R. D.; Linde, A. T.

1986-10-01

Measurements of dilational earth strain in the frequency band 25-10-5 Hz have been made on a deep borehole strainmeter installed near the San Andreas fault. These data are used to determine seismic radiation fields during nuclear explosions, teleseisms, local earthquakes, and ground noise during seismically quiet times. Strains of less than 10-10 on these instruments can be clearly resolved at short periods (< 10 s) and are recorded with wide dynamic range digital recorders. This permits measurement of the static and dynamic strain variations in the near field of local earthquakes. Noise spectra for earth strain referenced to 1 (strain)2/Hz show that strain resolution decreases at about 10 dB per decade of frequency from -150 dB at 10-4 Hz to -223 dB at 10 Hz. Exact expressions are derived to relate the volumetric strain and displacement field for a homogeneous P wave in a general viscoelastic solid as observed on colocated dilatometers and seismometers. A rare near-field recording of strain and seismic velocity was obtained on May 26, 1984, from an earthquake (ML 3.2) at a hypocentral distance of 3.2 km near the San Andreas fault at San Juan Bautista, California. While the data indicate no precursory strain release at the 5 × 10-11 strain level, a coseismic strain release of 1.86 nanostrain was observed. This change in strain is consistent with that calculated from a simple dislocation model of the event. Ground displacement spectra, determined from the downhole strain data and instrument-corrected surface seismic data, suggest that source parameters estimated from surface recordings may be contaminated by amplification effects in near-surface low-velocity materials.

Novel high pressure hexagonal OsB2 by mechanochemistry

International Nuclear Information System (INIS)

Xie, Zhilin; Graule, Moritz; Orlovskaya, Nina; Andrew Payzant, E.; Cullen, David A.; Blair, Richard G.

2014-01-01

Hexagonal OsB 2 , a theoretically predicted high-pressure phase, has been synthesized for the first time by a mechanochemical method, i.e., high energy ball milling. X-ray diffraction indicated that formation of hexagonal OsB 2 begins after 2.5 h of milling, and the reaction reaches equilibrium after 18 h of milling. Rietveld refinement of the powder data indicated that hexagonal OsB 2 crystallizes in the P63/mmc space group (No. 194) with lattice parameters of a=2.916 Å and c=7.376 Å. Transmission electron microscopy confirmed the appearance of the hexagonal OsB 2 phase after high energy ball milling. in situ X-ray diffraction experiments showed that the phase is stable from −225 °C to 1050 °C. The hexagonal OsB 2 powder was annealed at 1050 °C for 6 days in vacuo to improve crystallinity and remove strain induced during the mechanochemical synthesis. The structure partially converted to the orthorhombic phase (20 wt%) after fast current assisted sintering of hexagonal OsB 2 at 1500 °C for 5 min. Mechanochemical approaches to the synthesis of hard boride materials allow new phases to be produced that cannot be prepared using conventional methods. - Graphical abstract: High resolution transmission electron micrograph of hexagonal OsB 2 nanocrystallite with corresponding fast Fourier transform and simulated diffraction pattern. - Highlights: • Hexagonal OsB 2 has been synthesized for the first time by mechanochemical method. • Hexagonal OsB 2 crystallizes in P63/mmc space group (No. 194), a=2.916 Å and c=7.376 Å. • The hexagonal structure was confirmed by a transmission electron microscope. • No phase transformation was observed after being annealed at 1050 °C for 6 days. • 20 wt% of h-OsB 2 was transformed to o-OsB 2 after being sintered at 1500 °C for 5 min

Development of a novel vaccine against canine parvovirus infection with a clinical isolate of the type 2b strain

OpenAIRE

Park, Seon Ah; Park, Seung-Yong; Song, Chang-Seon; Choi, In-Soo; Kim, Hwi Yool; Lee, Joong-Bok; Lee, Nak-Hyung

2012-01-01

Purpose In spite of an extensive vaccination program, parvoviral infections still pose a major threat to the health of dogs. Materials and Methods We isolated a novel canine parvovirus (CPV) strain from a dog with enteritis. Nucleotide and amino acid sequence analysis of the isolate showed that it is a novel type 2b CPV with asparagine at the 426th position and valine at the 555th position in VP2. To develop a vaccine against CPV infection, we passaged the isolate 4 times in A72 cells. Result...

Immunochemical characterization of the O antigens of two Proteus strains, O8-related antigen of Proteus mirabilis 12 B-r and O2-related antigen of Proteus genomospecies 5/6 12 B-k, infecting a hospitalized patient in Poland.

Science.gov (United States)

Drzewiecka, Dominika; Shashkov, Alexander S; Arbatsky, Nikolay P; Knirel, Yuriy A

2016-05-01

A hospitalized 73-year-old woman was infected with a Proteus mirabilis strain, 12 B-r, isolated from the place of injection of a blood catheter. Another strain, 12 B-k, recognized as Proteus genomospecies 5 or 6, was isolated from the patient's faeces, which was an example of a nosocomial infection rather than an auto-infection. Serological investigation using ELISA and Western blotting showed that strain 12 B-k from faeces belonged to the Proteus O2 serogroup. Strain 12 B-r from the wound displayed cross-reactions with several Proteus O serogroups due to common epitopes on the core or O-specific parts of the lipopolysaccharide. Studies of the isolated 12 B-r O-specific polysaccharide by NMR spectroscopy revealed its close structural similarity to that of Proteus O8. The only difference in 12 B-r was the presence of an additional GlcNAc-linked phosphoethanolamine residue, which creates a putative epitope responsible for the cross-reactivity with Pt. mirabilis O16. The new O-antigen form could appear as a result of adaptation of the bacterium to a changing environment. On the basis of the data obtained, we suggest division of the O8 serogroup into two subgroups: O8a for strains of various Proteus species that have been previously classified into the O8 serogroup, and O8a,b for Pt. mirabilis 12 B-r, where 'a' is a common epitope and 'b' is a phosphoethanolamine-associated epitope. These findings further confirm serological and structural heterogeneity of O antigens of Proteus strains isolated lately from patients in Poland.

The orphan germinant receptor protein GerXAO (but not GerX3b) is essential for L-alanine induced germination in Clostridium botulinum Group II.

Science.gov (United States)

Brunt, Jason; Carter, Andrew T; Pye, Hannah V; Peck, Michael W

2018-05-04

Clostridium botulinum is an anaerobic spore forming bacterium that produces the potent botulinum neurotoxin that causes a severe and fatal neuro-paralytic disease of humans and animals (botulism). C. botulinum Group II is a psychrotrophic saccharolytic bacterium that forms spores of moderate heat resistance and is a particular hazard in minimally heated chilled foods. Spore germination is a fundamental process that allows the spore to transition to a vegetative cell and typically involves a germinant receptor (GR) that responds to environmental signals. Analysis of C. botulinum Group II genomes shows they contain a single GR cluster (gerX3b), and an additional single gerA subunit (gerXAO). Spores of C. botulinum Group II strain Eklund 17B germinated in response to the addition of L-alanine, but did not germinate following the addition of exogenous Ca 2+ -DPA. Insertional inactivation experiments in this strain unexpectedly revealed that the orphan GR GerXAO is essential for L-alanine stimulated germination. GerX3bA and GerX3bC affected the germination rate but were unable to induce germination in the absence of GerXAO. No role could be identified for GerX3bB. This is the first study to identify the functional germination receptor of C. botulinum Group II.

Management of group B streptococcal bacteriuria in pregnancy.

Science.gov (United States)

Allen, Victoria M; Yudin, Mark H

2012-05-01

To provide information regarding the management of group B streptococcal (GBS) bacteriuria to midwives, nurses, and physicians who are providing obstetrical care. The outcomes considered were neonatal GBS disease, preterm birth, pyelonephritis, chorioamnionitis, and recurrence of GBS colonization. Medline, PubMed, and the Cochrane database were searched for articles published in English to December 2010 on the topic of GBS bacteriuria in pregnancy. Bacteriuria is defined in this clinical practice guideline as the presence of bacteria in urine, regardless of the number of colony-forming units per mL (CFU/mL). Low colony counts refer to pregnancies in which it is appropriate to treat GBS bacteriuria to optimize maternal and perinatal outcomes, to reduce the occurrences of antibiotic anaphylaxis, and to prevent increases in antibiotic resistance to GBS and non-GBS pathogens. No cost-benefit analysis is provided. 1. Treatment of any bacteriuria with colony counts ≥ 100 000 CFU/mL in pregnancy is an accepted and recommended strategy and includes treatment with appropriate antibiotics. (II-2A) 2. Women with documented group B streptococcal bacteriuria (regardless of level of colony-forming units per mL) in the current pregnancy should be treated at the time of labour or rupture of membranes with appropriate intravenous antibiotics for the prevention of early-onset neonatal group B streptococcal disease. (II-2A) 3. Asymptomatic women with urinary group B streptococcal colony counts pregnancy should not be treated with antibiotics for the prevention of adverse maternal and perinatal outcomes such as pyelonephritis, chorioamnionitis, or preterm birth. (II-2E) 4. Women with documented group B streptococcal bacteriuria should not be re-screened by genital tract culture or urinary culture in the third trimester, as they are presumed to be group B streptococcal colonized. (II-2D).

Uptake and impact of vaccinating school age children against influenza during a season with circulation of drifted influenza A and B strains, England, 2014/15.

Science.gov (United States)

Pebody, Richard G; Green, Helen K; Andrews, Nick; Boddington, Nicola L; Zhao, Hongxin; Yonova, Ivelina; Ellis, Joanna; Steinberger, Sophia; Donati, Matthew; Elliot, Alex J; Hughes, Helen E; Pathirannehelage, Sameera; Mullett, David; Smith, Gillian E; de Lusignan, Simon; Zambon, Maria

2015-01-01

The 2014/15 influenza season was the second season of roll-out of a live attenuated influenza vaccine (LAIV) programme for healthy children in England. During this season, besides offering LAIV to all two to four year olds, several areas piloted vaccination of primary (4-11 years) and secondary (11-13 years) age children. Influenza A(H3N2) circulated, with strains genetically and antigenically distinct from the 2014/15 A(H3N2) vaccine strain, followed by a drifted B strain. We assessed the overall and indirect impact of vaccinating school age children, comparing cumulative disease incidence in targeted and non-targeted age groups in vaccine pilot to non-pilot areas. Uptake levels were 56.8% and 49.8% in primary and secondary school pilot areas respectively. In primary school age pilot areas, cumulative primary care influenza-like consultation, emergency department respiratory attendance, respiratory swab positivity, hospitalisation and excess respiratory mortality were consistently lower in targeted and non-targeted age groups, though less for adults and more severe end-points, compared with non-pilot areas. There was no significant reduction for excess all-cause mortality. Little impact was seen in secondary school age pilot only areas compared with non-pilot areas. Vaccination of healthy primary school age children resulted in population-level impact despite circulation of drifted A and B influenza strains.

Influence of gastrointestinal system conditions on adhesion of exopolysaccharide-producing Lactobacillus delbrueckii subsp. bulgaricus strains to caco-2 cells

Directory of Open Access Journals (Sweden)

Derya Onal Darilmaz

2011-10-01

Full Text Available This study aimed to assess the transit tolerance of potential probiotic dairy Lactobacillus strains in human uppergastrointestinal tract in vitro, and to evaluate the effect of EPS production on the viability and adhesion of these strains. Survival and adhesion of two exopolysaccharide (EPS-producing L. delbrueckii subsp. bulgaricus strains (B3 and B2 and E. coli ATCC11229 were assessed after the exposure of different pH (gastric juice and gastric plus pancreatic juice challenges. In the artificial gastric juice (pH 2, both the viability of the strain B3 and B2 was decreased. Artificial juice treatments significantly reduced the adhesion to caco-2 cells (P< 0.05. High EPS-producing B3 survived better in the adverse gastrointestinal conditions and showed better ability of adhesion to Caco-2 cells when assessed for competition with E. coli ATCC 11229 compared to low EPS-producing B2. This investigation showed that EPS production could be affected or be involved in the viability, adherence and competition of L. delbrueckii subsp. bulgaricus strains and support the potential of B3 strain for development of new probiotic products.

Synthesis and antimalarial testing of neocryptolepine analogues: addition of ester function in SAR study of 2,11-disubstituted indolo[2,3-b]quinolines.

Science.gov (United States)

Lu, Wen-Jie; Wicht, Kathryn J; Wang, Li; Imai, Kento; Mei, Zhen-Wu; Kaiser, Marcel; El Sayed, Ibrahim El Tantawy; Egan, Timothy J; Inokuchi, Tsutomu

2013-06-01

This report describes the synthesis, and in vitro and in vivo antimalarial evaluations of certain ester-modified neocryptolepine (5-methyl-5H-indolo[2,3-b]quinoline) derivatives. The modifications were carried out by introducing ester groups at the C2 and/or C9 position on the neocryptolepine core and the terminal amino group of the 3-aminopropylamine substituents at the C11 position with a urea/thiourea unit. The antiplasmodial activities of our derivative agents against two different strains (CQS: NF54, and CQR: K1) and the cytotoxic activity against normal L6 cells were evaluated. The test results showed that the ester modified neocryptolepine derivatives have higher antiplasmodial activities against both strains and a low cytotoxic activity against normal cells. The best results were achieved by compounds 9c and 12b against the NF54 strain with the IC50/SI value as 2.27 nM/361 and 1.81 nM/321, respectively. While against K1 strain, all the tested compounds showed higher activity than the well-known antimalarial drug chloroquine. Furthermore, the compounds were tested for β-haematin inhibition and 12 were found to be more active than chloroquine (IC50 = 18 μM). Structure activity relationship studies exposed an interesting linear correlation between polar surface area of the molecule and β-haematin inhibition for this series. In vivo testing of compounds 7 and 8a against NF54 strain on Plasmodium berghei female mice showed that the introduction of the ester group increased the antiplasmodial activity of the neocryptolepine core substantially. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Noninvasive characterization of carotid plaque strain.

Science.gov (United States)

Khan, Amir A; Sikdar, Siddhartha; Hatsukami, Thomas; Cebral, Juan; Jones, Michael; Huston, John; Howard, George; Lal, Brajesh K

2017-06-01

Current risk stratification of internal carotid artery plaques based on diameter-reducing percentage stenosis may be unreliable because ischemic stroke results from plaque disruption with atheroembolization. Biomechanical forces acting on the plaque may render it vulnerable to rupture. The feasibility of ultrasound-based quantification of plaque displacement and strain induced by hemodynamic forces and their relationship to high-risk plaques have not been determined. We studied the feasibility and reliability of carotid plaque strain measurement from clinical B-mode ultrasound images and the relationship of strain to high-risk plaque morphology. We analyzed carotid ultrasound B-mode cine loops obtained in patients with asymptomatic ≥50% stenosis during routine clinical scanning. Optical flow methods were used to quantify plaque motion and shear strain during the cardiac cycle. The magnitude (maximum absolute shear strain rate [MASSR]) and variability (entropy of shear strain rate [ESSR] and variance of shear strain rate [VSSR]) of strain were combined into a composite shear strain index (SSI), which was assessed for interscan repeatability and correlated with plaque echolucency. Nineteen patients (mean age, 70 years) constituting 36 plaques underwent imaging; 37% of patients (n = 7) showed high strain (SSI ≥0.5; MASSR, 2.2; ESSR, 39.7; VSSR, 0.03) in their plaques; the remaining clustered into a low-strain group (SSI routine B-mode imaging using clinical ultrasound machines. High plaque strain correlates with known high-risk echolucent morphology. Strain measurement can complement identification of patients at high risk for plaque disruption and stroke. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Investigation of the translation-initiation factor IF2 gene, infB, as a tool to study the population structure of Streptococcus agalactiae

DEFF Research Database (Denmark)

Hedegaard, J; Hauge, M; Fage-Larsen, J

2000-01-01

The sequence of infB, encoding the prokaryotic translation-initiation factor 2 (IF2), was determined in eight strains of Streptococcus agalactiae (group B streptococcus) and an alignment revealed limited intraspecies diversity within S. agalactiae. The amino acid sequence of IF2 from S. agalactiae...... and from related species were aligned and revealed an interspecies conserved central and C-terminal part, and an N-terminal part that is highly variable in length and amino acid sequence. The diversity and relationships in a collection of 58 genetically distinct strains of S. agalactiae were evaluated...... by comparing a partial sequence of infB. A total of six alleles were detected for the region of infB analysed. The alleles correlated with the separation of the same strains of S. agalactiae into major evolutionary lineages, as shown in previous work. The partial sequences of infB were furthermore used...

A naturally occurring mutation in ropB suppresses SpeB expression and reduces M1T1 group A streptococcal systemic virulence.

Directory of Open Access Journals (Sweden)

Andrew Hollands

Full Text Available Epidemiological studies of group A streptococcus (GAS have noted an inverse relationship between SpeB expression and invasive disease. However, the role of SpeB in the course of infection is still unclear. In this study we utilize a SpeB-negative M1T1 clinical isolate, 5628, with a naturally occurring mutation in the gene encoding the regulator RopB, to elucidate the role of RopB and SpeB in systemic virulence. Allelic exchange mutagenesis was used to replace the mutated ropB allele in 5628 with the intact allele from the well characterized isolate 5448. The inverse allelic exchange was also performed to replace the intact ropB in 5448 with the mutated allele from 5628. An intact ropB was found to be essential for SpeB expression. While the ropB mutation was shown to have no effect on hemolysis of RBC's, extracellular DNase activity or survival in the presence of neutrophils, strains with the mutated ropB allele were less virulent in murine systemic models of infection. An isogenic SpeB knockout strain containing an intact RopB showed similarly reduced virulence. Microarray analysis found genes of the SpeB operon to be the primary target of RopB regulation. These data show that an intact RopB and efficient SpeB production are necessary for systemic infection with GAS.

Cell surface groups of two picocyanobacteria strains studied by zeta potential investigations, potentiometric titration, and infrared spectroscopy.

Science.gov (United States)

Dittrich, Maria; Sibler, Sabine

2005-06-15

In order to clarify the role of picocyanobacteria in aquatic biogeochemical processes (e.g., calcite precipitation), cell surface properties need to be investigated. An experimental study of the cell surface characteristics of two Synechococcus-type unicellular autotrophic picocyanobacterial strains was carried out. One strain was isolated from Lake Plon and contained phycocyanin, the other strain came from Lago Maggiore and was rich in phycoerythrin. Potentiometric titrations were conducted to determine the different types of sites present on the bacteria cell walls. Infrared spectroscopy allowed characterization of the various functional groups (RNH(2), RCOOH, ROH, RPO(2)) and investigations of zeta potential provided insight into the isoelectrical points of the strains. Titrations reveal three distinct sites on the bacterial surfaces of phycocyanin- and phycoerythrin-rich strains with pK values of 4.8+/-0.3/5.0+/-0.2, 6.6+/-0.2/6.7+/-0.4, and 8.8+/-0.1/8.7+/-0.2, corresponding to carboxyl, phosphate, and amine groups with surface densities of 2.6+/-0.4/7.4+/-1.6 x 10(-4), 1.9+/-0.5/4.4+/-0.8 x 10(-4), and 2.5+/-0.4/4.8+/-0.7 x 10(-4) mol/g of dry bacteria. The deprotonation constants are similar to those of bacterial strains and site densities are also within an order of magnitude of other strains. The phycoerythrin-rich strain had a higher number of binding sites than the phycocyanin-rich strain. The results showed that picocyanobacteria may adsorb either calcium cations or carbonate anions and therefore strongly influence the biogeochemical cycling of calcite in pelagic systems.

The role of MHC haplotypes H2d/H2b in mouse resistance/susceptibility to cyst formation is influenced by the lineage of infective Toxoplasma gondii strain

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Marianne G. Resende

2008-03-01

Full Text Available Toxoplasma gondii strains displaying the Type I/III genotype are associated with acquired ocular toxoplasmosis in humans. Here, we used a mice model to characterize some immunological mechanisms involved in host resistance to infection with such strains. We have chosen the Type I/III strains D8, G2 and P-Br, which cause a chronic infection in mice that resembles human toxoplamosis. Mice deficient of molecules MyD88, IFN-gamma, and IL-12 were susceptible to all three parasite strains. This finding indicates the importance of innate mechanisms in controlling infection. On the other hand, MHC haplotype did not influenced resistance/susceptibility; since mice lineages displaying a same genetic background but different MHC haplotypes (H2b or H2d developed similar mortality and cyst numbers after infection with those strains. In contrast, the C57BL/6 genetic background, and not MHC haplotype, was critical for development of intestinal inflammation caused by any of the studied strains. Finally, regarding effector mechanisms, weobserved that B and CD8+ T lymphocytes controlled survival,whereas the inducible nitric oxide synthase influenced cyst numbers in brains of mice infected with Type I/III strains. These findings are relevant to further understanding of the immunologic mechanisms involved in host protection and pathogenesis during infection with T. gondii.Cepas de Toxoplasma gondii que apresentam o genótipo I/III são associadas a toxoplasmose ocular adquirida em humanos. No presente trabalho, nós utilizamos um modelo da doença em camundongos para caracterizar mecanismos imunológicos envolvidos na resistência do hospedeiro à infecção por aquelas cepas. Escolhemos as cepas D8, G2 e P-Br, que causam infecção crônica em camundongos, semelhante à toxoplasmose humana. Camundongos deficientes em MyD88, IFN-G e IL-12 foram susceptíveis a infecções com todas as três linhagens do parasita. Esses dados indicam a importância de mecanismos

Vaccines for prevention of group B meningococcal disease: Not your father's vaccines.

Science.gov (United States)

Harrison, Lee H

2015-11-27

For decades, there was no licensed vaccine for prevention of endemic capsular group B meningococcal disease, despite the availability of vaccines for prevention of the other most common meningococcal capsular groups. Recently, however, two new vaccines have been licensed for prevention of group B disease. Although immunogenic and considered to have an acceptable safety profile, there are many scientific unknowns about these vaccines, including effectiveness against antigenically diverse endemic meningococcal strains; duration of protection; whether they provide any herd protection; and whether there will be meningococcal antigenic changes that will diminish effectiveness over time. In addition, these vaccines present societal dilemmas that could influence how they are used in the U.S., including high vaccine cost in the face of a historically low incidence of meningococcal disease. These issues are discussed in this review. Copyright © 2015 American Journal of Preventive Medicine. Published by Elsevier Ltd.. All rights reserved.

Expression of the Blood-Group-Related Gene B4galnt2 Alters Susceptibility to Salmonella Infection.

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Philipp Rausch

2015-07-01

Full Text Available Glycans play important roles in host-microbe interactions. Tissue-specific expression patterns of the blood group glycosyltransferase β-1,4-N-acetylgalactosaminyltransferase 2 (B4galnt2 are variable in wild mouse populations, and loss of B4galnt2 expression is associated with altered intestinal microbiota. We hypothesized that variation in B4galnt2 expression alters susceptibility to intestinal pathogens. To test this, we challenged mice genetically engineered to express different B4galnt2 tissue-specific patterns with a Salmonella Typhimurium infection model. We found B4galnt2 intestinal expression was strongly associated with bacterial community composition and increased Salmonella susceptibility as evidenced by increased intestinal inflammatory cytokines and infiltrating immune cells. Fecal transfer experiments demonstrated a crucial role of the B4galnt2-dependent microbiota in conferring susceptibility to intestinal inflammation, while epithelial B4galnt2 expression facilitated epithelial invasion of S. Typhimurium. These data support a critical role for B4galnt2 in gastrointestinal infections. We speculate that B4galnt2-specific differences in host susceptibility to intestinal pathogens underlie the strong signatures of balancing selection observed at the B4galnt2 locus in wild mouse populations.

A phase 1 study of a meningococcal native outer membrane vesicle vaccine made from a group B strain with deleted lpxL1 and synX, over-expressed factor H binding protein, two PorAs and stabilized OpcA expression.

Science.gov (United States)

Keiser, P B; Biggs-Cicatelli, S; Moran, E E; Schmiel, D H; Pinto, V B; Burden, R E; Miller, L B; Moon, J E; Bowden, R A; Cummings, J F; Zollinger, W D

2011-02-04

This phase I clinical trial assessed the safety and immunogenicity of a native outer membrane vesicle (NOMV) vaccine prepared from an lpxL1(-) synX(-) mutant of strain 8570(B:4:P1.19,15:L8-5) of Neisseria meningitidis. Additional mutations enhance the expression of factor H binding protein variant 1 (fHbp v.1), stabilize expression of OpcA and introduce a second PorA (P1.22,14). Thirty-six volunteers were assigned to one of four dose groups (10, 25, 50 and 75 mcg, based on protein content) to receive three intramuscular injections at six week intervals with aluminum hydroxide adjuvant. Specific local and systemic adverse events were solicited by diary and at visits on days 2, 7, and 14 after each vaccination. Blood chemistries, complete blood count, and coagulation studies were measured on each vaccination day and again 2 and 14 days later. Blood for ELISA and serum bactericidal assays was drawn two and six weeks after each vaccination. The proportion of volunteers who developed a fourfold or greater increase in bactericidal activity to the wild type parent of the vaccine strain at two weeks after the third dose was 27 out of 34 (0.79, 95% C.I. 0.65-0.93). Against four other group B strains the response rate ranged from 41% to 82% indicating a good cross reactive antibody response. Depletion assays show contributions to bactericidal activity from antibodies to lipooligosaccharide (LOS), fHbp v.1 and OpcA. Published by Elsevier Ltd.

Successful ABO-Incompatible Renal Transplantation:  Blood Group A1B Donor Into A2B Recipient With Anti-A1 Isoagglutinins.

Science.gov (United States)

Fadeyi, Emmanuel A; Stratta, Robert J; Farney, Alan C; Pomper, Gregory J

2016-08-01

Transplantation of the blood group A2B in a recipient was successfully performed in the setting of receiving a deceased donor kidney from an "incompatible" A1B donor. The donor and recipient were both typed for ABO blood group, including ABO genotyping. The donor and recipient were tested for ABO, non-ABO, and human leukocyte antigen (HLA) antibodies. The donor and recipient were typed for HLA antigens, including T- and B-flow cytometry crossmatch tests. The recipient's RBCs were negative with A1 lectin, and immunoglobulin G anti-A1 was demonstrated in the recipient's plasma. The donor-recipient pair was a four-antigen HLA mismatch, but final T- and B-flow cytometry crossmatch tests were compatible. The transplant procedure was uneventful; the patient experienced immediate graft function with no episodes of rejection or readmissions more than 2 years later. It may be safe to transplant across the A1/A2 blood group AB mismatch barrier in the setting of low titer anti-A1 isoagglutinins without the need for pretransplant desensitization even if the antibody produced reacts with anti-human globulin. © American Society for Clinical Pathology, 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Meningococcal group B vaccines.

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Findlow, Jamie

2013-06-01

Meningococcal disease remains a devastating and feared infection with a significant morbidity and mortality profile. The successful impact of meningococcal capsular group C glyconconjugate vaccines introduced into the UK infant immunization schedule in 1999, has resulted in >80% of disease now being attributable to meningococcal capsular group B (MenB). MenB glyconconjugate vaccines are not immunogenic and hence, vaccine design has focused on sub-capsular antigens. Recently, a four component vaccine to combat MenB disease (4CMenB) has progressed through clinical development and was approved by the European Medicines Agency at the end of 2012. This vaccine has proven safe and immunogenic and has been predicted to provide protection against ~73% of the MenB disease from England and Wales. Recommendation/implementation of the vaccine into the UK infant schedule is currently being evaluated. 4CMenB has the potential to provide protection against a significant proportion of MenB disease in the UK which is currently unpreventable.

The prevention of early-onset neonatal group B streptococcal disease.

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Money, Deborah; Allen, Victoria M

2013-10-01

reduced with induction of labour. (I) There is no evidence to support safe neonatal outcomes with expectant management in this clinical situation. 1. Offer all women screening for colonization with group B streptococcus at 35 to 37 weeks' gestation with culture taken from one swab first to the vagina and then to the rectum (through the anal sphincter). (II-1A) This includes women with planned Caesarean delivery because of their risk of labour or ruptured membranes earlier than the scheduled Caesarean delivery. (II-2B) 2. Because of the association of heavy colonization with early onset neonatal disease, provide intravenous antibiotic prophylaxis for group B streptococcus at the onset of labour or rupture of the membranes to: • any woman positive for group B streptococcus by vaginal/rectal swab culture screening done at 35 to 37 weeks' gestation (II-2B); • any woman with an infant previously infected with group B streptococcus (II-3B); • any woman with documented group B streptococcus bacteriuria (regardless of level of colony-forming units) in the current pregnancy. (II-2A) 3. Manage all women who are membranes with intravenous group B streptococcus antibiotic prophylaxis for a minimum of 48 hours, unless there has been a negative vaginal/rectal swab culture or rapid nucleic acid-based test within the previous 5 weeks. (II-3A) 4. Treat all women with intrapartum fever and signs of chorioamnionitis with broad spectrum intravenous antibiotics targeting chorioamnionitis and including coverage for group B streptococcus, regardless of group B streptococcus status and gestational age. (II-2A) 5. Request antibiotic susceptibility testing on group B streptococcus-positive urine and vaginal/rectal swab cultures in women who are thought to have a significant risk of anaphylaxis from penicillin. (II-1A) 6. If a woman with pre-labour rupture of membranes at ≥ 37 weeks' gestation is positive for group B streptococcus by vaginal/rectal swab culture screening, has had group B

Group B Strep Infection

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... IV) to kill the germs. If you take antibiotics while you’re in labor, the chances are very good that your baby won’t get this infection. What if my baby has group B strep? If your baby gets group B strep, he or she will be treated with IV antibiotics to kill the bacteria. Your baby will stay ...

Srv mediated dispersal of streptococcal biofilms through SpeB is observed in CovRS+ strains.

Directory of Open Access Journals (Sweden)

Kristie L Connolly

Full Text Available Group A Streptococcus (GAS is a human specific pathogen capable of causing both mild infections and severe invasive disease. We and others have shown that GAS is able to form biofilms during infection. That is to say, they form a three-dimensional, surface attached structure consisting of bacteria and a multi-component extracellular matrix. The mechanisms involved in regulation and dispersal of these GAS structures are still unclear. Recently we have reported that in the absence of the transcriptional regulator Srv in the MGAS5005 background, the cysteine protease SpeB is constitutively produced, leading to increased tissue damage and decreased biofilm formation during a subcutaneous infection in a mouse model. This was interesting because MGAS5005 has a naturally occurring mutation that inactivates the sensor kinase domain of the two component regulatory system CovRS. Others have previously shown that strains lacking covS are associated with decreased SpeB production due to CovR repression of speB expression. Thus, our results suggest the inactivation of srv can bypass CovR repression and lead to constitutive SpeB production. We hypothesized that Srv control of SpeB production may be a mechanism to regulate biofilm dispersal and provide a mechanism by which mild infection can transition to severe disease through biofilm dispersal. The question remained however, is this mechanism conserved among GAS strains or restricted to the unique genetic makeup of MGAS5005. Here we show that Srv mediated control of SpeB and biofilm dispersal is conserved in the invasive clinical isolates RGAS053 (serotype M1 and MGAS315 (serotype M3, both of which have covS intact. This work provides additional evidence that Srv regulated control of SpeB may mediate biofilm formation and dispersal in diverse strain backgrounds.

Expression of Heterologous Cellulases in Thermotoga sp. Strain RQ2

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Hui Xu

2015-01-01

Full Text Available The ability of Thermotoga spp. to degrade cellulose is limited due to a lack of exoglucanases. To address this deficiency, cellulase genes Csac_1076 (celA and Csac_1078 (celB from Caldicellulosiruptor saccharolyticus were cloned into T. sp. strain RQ2 for heterologous overexpression. Coding regions of Csac_1076 and Csac_1078 were fused to the signal peptide of TM1840 (amyA and TM0070 (xynB, resulting in three chimeric enzymes, namely, TM1840-Csac_1078, TM0070-Csac_1078, and TM0070-Csac_1076, which were carried by Thermotoga-E. coli shuttle vectors pHX02, pHX04, and pHX07, respectively. All three recombinant enzymes were successfully expressed in E. coli DH5α and T. sp. strain RQ2, rendering the hosts with increased endo- and/or exoglucanase activities. In E. coli, the recombinant enzymes were mainly bound to the bacterial cells, whereas in T. sp. strain RQ2, about half of the enzyme activities were observed in the culture supernatants. However, the cellulase activities were lost in T. sp. strain RQ2 after three consecutive transfers. Nevertheless, this is the first time heterologous genes bigger than 1 kb (up to 5.3 kb in this study have ever been expressed in Thermotoga, demonstrating the feasibility of using engineered Thermotoga spp. for efficient cellulose utilization.

[Physiological and biochemical characteristics and capacity for polyhydroxyalkanoates synthesis in a glucose-utilizing strain of hydrogen-oxidizing bacteria, Ralstonia eutropha B8562].

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Volova, T G; Kozhevnikov, I V; Dolgopolova, Iu B; Trusova, M Iu; Kalacheva, G S; Aref'eva, Iu V

2005-01-01

The physiological, biochemical, genetic, and cultural characteristics of the glucose-utilizing mutant strain Ralstonia eutropha B8562 were investigated in comparison with the parent strain R. eutropha B5786. The morphological, cultural, and biochemical characteristics of strain R. eutropha B8562 were similar to those of strain R. eutropha B5786. Genetic analysis revealed differences between the 16S rRNA gene sequences of these strains. The growth characteristics of the mutant using glucose as the sole carbon and energy source were comparable with those of the parent strain grown on fructose. Strain B8562 was characterized by high yields of polyhydroxyalkanoate (PHA) from different carbon sources (CO2, fructose, and glucose). In batch culture with glucose under nitrogen limitation, PHA accumulation reached 90% of dry weight. In PHA, beta-hydroxybutyrate was predominant (over 99 mol %); beta-hydroxyvalerate (0.25-0.72 mol %) and beta-hydroxyhexanoate (0.008-1.5 mol %) were present as minor components. The strain has prospects as a PHA producer on glucose-containing media.

Novel high pressure hexagonal OsB{sub 2} by mechanochemistry

Energy Technology Data Exchange (ETDEWEB)

Xie, Zhilin; Graule, Moritz [Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, FL 32816 (United States); Orlovskaya, Nina, E-mail: Nina.Orlovskaya@ucf.edu [Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, FL 32816 (United States); Andrew Payzant, E. [Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831 (United States); Cullen, David A. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Blair, Richard G. [Department of Chemistry, University of Central Florida, Orlando, FL 32816 (United States)

2014-07-01

Hexagonal OsB{sub 2}, a theoretically predicted high-pressure phase, has been synthesized for the first time by a mechanochemical method, i.e., high energy ball milling. X-ray diffraction indicated that formation of hexagonal OsB{sub 2} begins after 2.5 h of milling, and the reaction reaches equilibrium after 18 h of milling. Rietveld refinement of the powder data indicated that hexagonal OsB{sub 2} crystallizes in the P63/mmc space group (No. 194) with lattice parameters of a=2.916 Å and c=7.376 Å. Transmission electron microscopy confirmed the appearance of the hexagonal OsB{sub 2} phase after high energy ball milling. in situ X-ray diffraction experiments showed that the phase is stable from −225 °C to 1050 °C. The hexagonal OsB{sub 2} powder was annealed at 1050 °C for 6 days in vacuo to improve crystallinity and remove strain induced during the mechanochemical synthesis. The structure partially converted to the orthorhombic phase (20 wt%) after fast current assisted sintering of hexagonal OsB{sub 2} at 1500 °C for 5 min. Mechanochemical approaches to the synthesis of hard boride materials allow new phases to be produced that cannot be prepared using conventional methods. - Graphical abstract: High resolution transmission electron micrograph of hexagonal OsB{sub 2} nanocrystallite with corresponding fast Fourier transform and simulated diffraction pattern. - Highlights: • Hexagonal OsB{sub 2} has been synthesized for the first time by mechanochemical method. • Hexagonal OsB{sub 2} crystallizes in P63/mmc space group (No. 194), a=2.916 Å and c=7.376 Å. • The hexagonal structure was confirmed by a transmission electron microscope. • No phase transformation was observed after being annealed at 1050 °C for 6 days. • 20 wt% of h-OsB{sub 2} was transformed to o-OsB{sub 2} after being sintered at 1500 °C for 5 min.

Meningococcal serogroup B strain coverage of the multicomponent 4CMenB vaccine with corresponding regional distribution and clinical characteristics in England, Wales, and Northern Ireland, 2007-08 and 2014-15: a qualitative and quantitative assessment.

Science.gov (United States)

Parikh, Sydel R; Newbold, Lynne; Slater, Stephanie; Stella, Maria; Moschioni, Monica; Lucidarme, Jay; De Paola, Rosita; Giuliani, Maria; Serino, Laura; Gray, Stephen J; Clark, Stephen A; Findlow, Jamie; Pizza, Mariagrazia; Ramsay, Mary E; Ladhani, Shamez N; Borrow, Ray

2017-07-01

The UK introduced 4CMenB-a multicomponent vaccine against serogroup B meningococcal disease-into the national infant immunisation programme in September, 2015. The Meningococcal Antigen Typing System (MATS) was used to estimate coverage by 4CMenB of invasive meningococcal group B isolates obtained during 2007-08 in England and Wales (MATS coverage). We aimed to repeat the MATS survey for invasive meningococcal group B isolates obtained during 2014-15, before 4CMenB introduction; compare strain coverage between 2007-08 and 2014-15; and investigate associations between MATS coverage, age, region, and disease outcomes. Invasive serogroup B meningococcal isolates from cases in England, Wales, and Northern Ireland during 2014-15 were assayed using MATS and compared with 2007-08 data. MATS coverage was assessed by geographical region and age group. Clinical characteristics, risk factors, and outcomes were assessed according to MATS coverage for 2014-15 English cases. In 2014-15, 165 of 251 (66%; 95% CI 52-80) meningococcal group B isolates were estimated by MATS to be covered by 4CMenB, compared with 391 of 535 (73%; 95% CI 57-87) in 2007-08. The proportion of MATS-positive isolates with one vaccine antigen increased from 23% (122 of 535) in 2007-08 to 31% (78 of 251) in 2014-15, whereas the proportion with more than one antigen fell from 50% (269 of 535) to 35% (87 of 251). This effect reflected changes in circulating strains, particularly ST-269 clonal complex strains. MATS coverage increased with age, varied by geographical region, and was associated with more severe disease. In 2014-15, two-thirds of meningococcal group B isolates were predicted to be covered by 4CMenB. Temporal changes in MATS coverage underscore the need for continued monitoring of antigen expression and diversity, particularly in countries with 4CMenB programmes. Public Health England, GlaxoSmithKline. Copyright © 2017 Elsevier Ltd. All rights reserved.

Immunogenicity and tolerability of a multicomponent meningococcal serogroup B (4CMenB) vaccine in healthy adolescents in Chile: a phase 2b/3 randomised, observer-blind, placebo-controlled study.

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Santolaya, María Elena; O'Ryan, Miguel L; Valenzuela, María Teresa; Prado, Valeria; Vergara, Rodrigo; Muñoz, Alma; Toneatto, Daniela; Graña, Gabriela; Wang, Huajun; Clemens, Ralf; Dull, Peter M

2012-02-18

Effective glycoconjugate vaccines against Neisseria meningitidis serogroups A, C, W-135, and Y have been developed, but serogroup B remains a major cause of severe invasive disease in infants and adolescents worldwide. We assessed immunogenicity and tolerability of a four-component vaccine (4CMenB) in adolescents. We did a randomised, observer-blind, placebo-controlled, study at 12 sites in Santiago and Valparaíso, Chile. Adolescents aged 11-17 years received one, two, or three doses of 4CMenB at 1 month, 2 month, or 6 month intervals. Immunogenicity was assessed as serum bactericidal activity using human complement (hSBA) against three reference strains for individual vaccine antigens, and assessed by ELISA against the fourth strain. Local and systemic reactions were recorded 7 days after each vaccination, and adverse events were monitored throughout the study. Participants were initially randomised to five groups (3:3:3:3:1) during the primary phase to receive either one dose, two doses 1 or 2 months apart, or three doses of 4CMenB, or three doses of placebo, with an additional three groups generated for the booster phase. All subjects received at least one dose of 4CMenB. Geometric mean titres, proportions of participants with serum bactericidal antibody titres of 4 or more, and Clopper-Pearson 95% CIs were calculated. The study is registered with ClinicalTrials.gov, number NCT00661713. Overall, 1631 adolescents (mean age 13·8 [SD 1·9] years) received at least one dose of 4CMenB. After two or three doses, 99-100% of recipients had hSBA titres of 4 or more against test strains, compared with 92-97% after one dose (pvaccine-related serious adverse events were reported and no significant safety signals were identified. On the basis of immunogenicity responses this study provides evidence for an adolescent 4CMenB vaccine schedule of two doses, 1-6 months apart, to provide protection against meningococcal B infection. The extent of this protection against

Safety and Immunogenicity Testing of an Intranasal Group B Meningococcal Native Outer Membrane Vesicle Vaccine in Healthy Volunteers

National Research Council Canada - National Science Library

Drabick, Joseph

1998-01-01

An intranasal vaccine composed of native outer membrane vesicles (NOMV) not exposed to detergent or denaturing agents was prepared from the group B meningococcal strain and tested in 32 healthy adult volunteers...

Estimation of lattice strain in nanocrystalline RuO2 by Williamson-Hall and size-strain plot methods.

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Sivakami, R; Dhanuskodi, S; Karvembu, R

2016-01-05

RuO2 nanoparticles (RuO2 NPs) have been successfully synthesized by the hydrothermal method. Structure and the particle size have been determined by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and transmission electron microscopy (TEM). UV-Vis spectra reveal that the optical band gap of RuO2 nanoparticles is red shifted from 3.95 to 3.55eV. BET measurements show a high specific surface area (SSA) of 118-133m(2)/g and pore diameter (10-25nm) has been estimated by Barret-Joyner-Halenda (BJH) method. The crystallite size and lattice strain in the samples have been investigated by Williamson-Hall (W-H) analysis assuming uniform deformation, deformation stress and deformation energy density, and the size-strain plot method. All other relevant physical parameters including stress, strain and energy density have been calculated. The average crystallite size and the lattice strain evaluated from XRD measurements are in good agreement with the results of TEM. Copyright © 2015 Elsevier B.V. All rights reserved.

Effectiveness and impact of a reduced infant schedule of 4CMenB vaccine against group B meningococcal disease in England: a national observational cohort study.

Science.gov (United States)

Parikh, Sydel R; Andrews, Nick J; Beebeejaun, Kazim; Campbell, Helen; Ribeiro, Sonia; Ward, Charlotte; White, Joanne M; Borrow, Ray; Ramsay, Mary E; Ladhani, Shamez N

2016-12-03

In September, 2015, the UK became the first country to introduce the multicomponent group B meningococcal (MenB) vaccine (4CMenB, Bexsero) into a publicly funded national immunisation programme. A reduced two-dose priming schedule was offered to infants at 2 months and 4 months, alongside an opportunistic catch-up for 3 month and 4 month olds. 4CMenB was predicted to protect against 73-88% of MenB strains. We aimed to assess the effectiveness and impact of 4CMenB in vaccine-eligible infants in England. Public Health England (PHE) undertakes enhanced surveillance of meningococcal disease through a combination of clinical, public health, and laboratory reporting. Laboratory-confirmed cases of meningococcal disease are followed up with PHE local health protection teams, general practitioners, and hospital clinicians to collect demographic data, vaccination history, clinical presentation, and outcome. For cases diagnosed between Sept 1, 2015, and June 30, 2016, vaccine effectiveness was assessed using the screening method. Impact was assessed by comparing numbers of cases of MenB in vaccine-eligible children to equivalent cohorts in the previous 4 years and to cases in vaccine-ineligible children. Coverage of 4CMenB in infants eligible for routine vaccination was high, achieving 95·5% for one dose and 88·6% for two doses by 6 months of age. Two-dose vaccine effectiveness was 82·9% (95% CI 24·1-95·2) against all MenB cases, equivalent to a vaccine effectiveness of 94·2% against the highest predicted MenB strain coverage of 88%. Compared with the prevaccine period, there was a 50% incidence rate ratio (IRR) reduction in MenB cases in the vaccine-eligible cohort (37 cases vs average 74 cases; IRR 0·50 [95% CI 0·36-0·71]; p=0·0001), irrespective of the infants' vaccination status or predicted MenB strain coverage. Similar reductions were observed even after adjustment for disease trends in vaccine-eligible and vaccine-ineligible children. The two-dose 4CMenB

Genotyping of Brucella melitensis and Brucella abortus strains currently circulating in Xinjiang, China.

Science.gov (United States)

Sun, Ming-Jun; Di, Dong-Dong; Li, Yan; Zhang, Zhi-Cheng; Yan, Hao; Tian, Li-Li; Jing, Zhi-Gang; Li, Jin-Ping; Jiang, Hai; Fan, Wei-Xing

2016-10-01

Brucellosis is a well-known zoonotic disease that can cause severe economic and healthcare losses. Xinjiang, one of the biggest livestock husbandry sectors in China, has gone through increasing incidence of brucellosis in cattle and small ruminants recently. In this paper, 50 B. melitensis strains and 9 B. abortus strains collected from across Xinjiang area (from 2010 to 2015) were genotyped using multiple locus variable-number tandem-repeat (VNTR) analysis (MLVA) and multi-locus sequence typing (MLST). Based on 8 loci (MLVA-8), 50 B. melitensis strains were classified into three genotypes. Genotypes 42 (n=38, 76%) and 63 (n=11, 22%) were part of the East Mediterranean group, and one genotype with pattern of 1-5-3-13-2-4-3-2 represents a single-locus variant from genotype 63. MLVA-16 resolved 50 B. melitensis strains into 28 genotypes, of which 15 are unique to Xinjiang and 10 are in common with those in adjacent country Kazakhstan and neighboring provinces of China. Minimum Spanning Tree (MST) analysis implies that B. melitensis strains collected from across Kazakhstan, Xinjiang and China areas may share a common origin. Nine B. abortus strains were sorted into three genotypes by MLVA-8, genotypes 36 (n=7, 77.8%), 86 (n=1, 11.1%) and a new genotype with pattern of 4-5-3-13-2-2-3-1. Each B. abortus strain showed distinct MLVA-16 genotypes, suggesting that B. abortus species may possess more genetic diversity than B. melitensis. Using MLST, most B. melitensis strains (n=49) were identified as sequence type ST8, and most B. abortus strains (n=8) were recognized as ST2. Two new sequence types, ST37 and ST38, represented by single strain from B. melitensis and B. abortus species respectively, were also detected in this study. These results could facilitate the pathogen surveillance in the forthcoming eradication programs and serve as a guide in source tracking in case of new outbreaks occur. Copyright © 2016 Elsevier B.V. All rights reserved.

Vaccination against group B streptococcus.

Science.gov (United States)

Heath, Paul T; Feldman, Robert G

2005-04-01

Streptococcus agalactiae (Group B streptococcus) is an important cause of disease in infants, pregnant women, the elderly and in immunosuppressed adults. An effective vaccine is likely to prevent the majority of infant disease (both early and late onset), as well as Group B streptococcus-related stillbirths and prematurity, to avoid the current real and theoretical limitations of intrapartum antibiotic prophylaxis, and to be cost effective. The optimal time to administer such a vaccine would be in the third trimester of pregnancy. The main limitations on the production of a Group B streptococcus vaccine are not technical or scientific, but regulatory and legal. A number of candidates including capsular conjugate vaccines using traditional carrier proteins such as tetanus toxoid and mutant diphtheria toxin CRM197, as well as Group B streptococcus-specific proteins such as C5a peptidase, protein vaccines using one or more Group B streptococcus surface proteins and mucosal vaccines, have the potential to be successful vaccines. The capsular conjugate vaccines using tetanus and CRM197 carrier proteins are the most advanced candidates, having already completed Phase II human studies including use in the target population of pregnant women (tetanus toxoid conjugate), however, no definitive protein conjugates have yet been trialed. However, unless the regulatory environment is changed specifically to allow the development of a Group B streptococcus vaccine, it is unlikely that one will ever reach the market.

Conserved genomic organisation of Group B Sox genes in insects.

Directory of Open Access Journals (Sweden)

Woerfel Gertrud

2005-05-01

Full Text Available Abstract Background Sox domain containing genes are important metazoan transcriptional regulators implicated in a wide rage of developmental processes. The vertebrate B subgroup contains the Sox1, Sox2 and Sox3 genes that have early functions in neural development. Previous studies show that Drosophila Group B genes have been functionally conserved since they play essential roles in early neural specification and mutations in the Drosophila Dichaete and SoxN genes can be rescued with mammalian Sox genes. Despite their importance, the extent and organisation of the Group B family in Drosophila has not been fully characterised, an important step in using Drosophila to examine conserved aspects of Group B Sox gene function. Results We have used the directed cDNA sequencing along with the output from the publicly-available genome sequencing projects to examine the structure of Group B Sox domain genes in Drosophila melanogaster, Drosophila pseudoobscura, Anopheles gambiae and Apis mellifora. All of the insect genomes contain four genes encoding Group B proteins, two of which are intronless, as is the case with vertebrate group B genes. As has been previously reported and unusually for Group B genes, two of the insect group B genes, Sox21a and Sox21b, contain introns within their DNA-binding domains. We find that the highly unusual multi-exon structure of the Sox21b gene is common to the insects. In addition, we find that three of the group B Sox genes are organised in a linked cluster in the insect genomes. By in situ hybridisation we show that the pattern of expression of each of the four group B genes during embryogenesis is conserved between D. melanogaster and D. pseudoobscura. Conclusion The DNA-binding domain sequences and genomic organisation of the group B genes have been conserved over 300 My of evolution since the last common ancestor of the Hymenoptera and the Diptera. Our analysis suggests insects have two Group B1 genes, SoxN and

[Study on immunogenicity of group A and group C meningococcal conjugate vaccine with coupling group B meningococcal outer membrane protein].

Science.gov (United States)

Ma, Fu-Bao; Tao, Hong; Wang, Hong-Jun

2009-10-01

To evaluate the Immunogenicity of Group A and Group C Meningococcal conjugate Vaccine with coupling Group B Meningococcal Outer Membrane Protein (Men B-OMP). 458 healthy children aged 3-5 months, 6-23 months, 2-6 years and 7-24 years were given the Groups A and C conjugate Vaccine with MenB-OMP or other vaccine as control group to measure the pre-and post-vaccination Men A and C and B by Serum Bactericidal Assay (SBA) in the double-blind randomized controlled trial. 97.65%-100% were 4 times or greater increase in SBA titer for the healthy children given the Groups A and C conjugate Vaccine with MenB-OMP, The geometric mean titer of SBA were 1:194-1:420, which significantly higber than controls. The Group A and C conjugate Vaccine with MenB-OMP was safe and well immunogenic.

UK parents' attitudes towards meningococcal group B (MenB) vaccination: a qualitative analysis.

Science.gov (United States)

Jackson, Cath; Yarwood, Joanne; Saliba, Vanessa; Bedford, Helen

2017-05-04

(1) To explore existing knowledge of, and attitudes, to group B meningococcal disease and serogroup B meningococcal (MenB) vaccine among parents of young children. (2) To seek views on their information needs. Cross-sectional qualitative study using individual and group interviews conducted in February and March 2015, prior to the introduction of MenB vaccine (Bexsero) into the UK childhood immunisation schedule. Community centres, mother and toddler groups, parents' homes and workplaces in London and Yorkshire. 60 parents of children under 2 years of age recruited via mother and baby groups and via an advert posted to a midwife-led Facebook group. Although recognising the severity of meningitis and septicaemia, parents' knowledge of group B meningococcal disease and MenB vaccine was poor. While nervous about fever, most said they would take their child for MenB vaccination despite its link to fever. Most parents had liquid paracetamol at home. Many were willing to administer it after MenB vaccination as a preventive measure, although some had concerns. There were mixed views on the acceptability of four vaccinations at the 12-month booster visit; some preferred one visit, while others favoured spreading the vaccines over two visits. Parents were clear on the information they required before attending the immunisation appointment. The successful implementation of the MenB vaccination programme depends on its acceptance by parents. In view of parents' recognition of the severity of meningitis and septicaemia, and successful introduction of other vaccines to prevent bacterial meningitis and septicaemia, the MenB vaccination programme is likely to be successful. However, the need for additional injections, the likelihood of post-immunisation fever and its management are issues about which parents will need information and reassurance from healthcare professionals. Public Health England has developed written information for parents, informed by these findings. �

Anti-H-Y responses of H-2b mutant mice.

Science.gov (United States)

Simpson, E; Gordon, R D; Chandler, P R; Bailey, D

1978-10-01

Two strains of H-2b mutant mice, H-2ba and H-2bf, in which the mutational event took place at H-2K, make anti-H-Y cytotoxic T cell responses which are H-2-restricted, Db-associated and indistinguishable in target cell specificity from those of H-2b mice. Thus, alteration of the H-2K molecule affects neither the Ir gene controlling the response, nor the associative antigen. On the other hand, one H-2Db mutant strain, H-2bo, although it makes a good anti-H-Y cytotoxic response, shows target cell specificity restricted to its own Dbo antigen(s), and neither H-2b, H-2ba or H-2bf anti-H-Y cytotoxic cells kill H-2bo male target cells. Thus, the alteration of the H-2Db molecule does not affect the Ir gene of H-2b mice, but it does alter the H-2Db-associative antigen.

Whole genome sequence analysis of an Alachlor and Endosulfan degrading Pseudomonas strain W15Feb9B isolated from Ochlockonee River, Florida

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Ashvini Chauhan

2016-06-01

Full Text Available We recently isolated a Pseudomonas sp. strain W15Feb9B from Ochlockonee River, Florida and demonstrated potent biodegradative activity against two commonly used pesticides - Alachlor [(2-chloro-2′,6′-diethylphenyl-N (methoxymethylacetanilide] and Endosulfan [(6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9methano-2,3,4-benzo(edi-oxathiepin-3-oxide], respectively. To further identify the repertoire of metabolic functions possessed by strain W15Feb9B, a draft genome sequence was obtained, assembled, annotated and analyzed. The genome sequence of strain 2385 has been deposited in GenBank under accession number JTKF00000000; BioSample number SAMN03151543. The sequences obtained from strain 2385 assembled into 192 contigs with a genome size of 6,031,588, G + C content of 60.34, and 5512 total number of putative genes. RAST annotated a total of 542 subsystems in the genome of strain W15Feb9B along with the presence of 5360 coding sequences. A genome wide survey of strain W15Feb9B indicated that it has the potential to degrade several other pollutants including atrazine, caprolactam, dioxin, PAHs (such as naphthalene and several chloroaromatic compounds.

Efficient production of lignocellulolytic enzymes xylanase, β-xylosidase, ferulic acid esterase and β-glucosidase by the mutant strain Aspergillus awamori 2B.361 U2/1

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Leda Maria Fortes Gottschalk

2013-01-01

Full Text Available The production of xylanase, β-xylosidase, ferulic acid esterase and β-glucosidase by Aspergillus awamori 2B.361 U2/1, a hyper producer of glucoamylase and pectinase, was evaluated using selected conditions regarding nitrogen nutrition. Submerged cultivations were carried out at 30 ºC and 200 rpm in growth media containing 30 g wheat bran/L as main carbon source and either yeast extract, ammonium sulfate, sodium nitrate or urea, as nitrogen sources; in all cases it was used a fixed molar carbon to molar nitrogen concentration of 10.3. The use of poor nitrogen sources favored the accumulation of xylanase, β-xylosidase and ferulic acid esterase to a peak concentrations of 44,880; 640 and 118 U/L, respectively, for sodium nitrate and of 34,580, 685 and 170 U/L, respectively, for urea. However, the highest β-glucosidase accumulation of 10,470 U/L was observed when the rich organic nitrogen source yeast extract was used. The maxima accumulation of filter paper activity, xylanase, β-xylosidase, ferulic acid esterase and β-glucosidase by A. awamori 2B.361 U2/1 was compared to that produced by Trichoderma reesei Rut-C30. The level of β-glucosidase was over 17-fold higher for the Aspergillus strain, whereas the levels of xylanase and β-xylosidase were over 2-fold higher. This strain also produced ferulic acid esterase (170 U/L, which was not detected in the T. reesei culture.

New versus old meningococcal group B vaccines: how the new ones may benefit infants & toddlers.

Science.gov (United States)

Panatto, D; Amicizia, D; Lai, P L; Cristina, M L; Domnich, A; Gasparini, R

2013-12-01

Invasive disease caused by Neisseria meningitidis is associated with high mortality and high disability rates and mainly affects children under one year of age. Vaccination is the best way to prevent meningococcal disease, especially in infants and toddlers. The introduction of massive meningococcal serogroup C vaccination has drastically reduced the incidence of disease caused by this serogroup, and serogroup B has now become the main causative agent in several industrialized countries. The first serogroup B vaccines, which were used for more than two decades, were based on outer membrane vesicles and proved to be protective only against specific epidemic strains in Cuba, Norway, Brazil and New Zealand. Moreover, these often elicited a scant immune response in young children. Innovative genomics-based reverse vaccinology subsequently enabled researchers to identify genes encoding for surface proteins that are able to elicit a strong immune response against several B strains. This important discovery led to the development and recent approval in Europe of the four-component meningococcal serogroup B (4CMenB) vaccine. Large clinical trials have shown high immunogenicity and tolerability and acceptable safety levels of 4CMenB in infants and toddlers. This vaccine is expected to cover a large number of circulating invasive strains and may also be efficacious against other serogroups. Young children are particularly vulnerable to the devastating consequences of meningococcal disease. Given the high performance of 4CMenB and its non-interference with routine vaccinations, this age-group will be the first to benefit from the introduction of this vaccine.

Draft Genome Sequences from a Novel Clade of Bacillus cereus Sensu Lato Strains, Isolated from the International Space Station

NARCIS (Netherlands)

Venkateswaran, Kasthuri; Checinska Sielaff, Aleksandra; Ratnayake, Shashikala; Pope, Robert K; Blank, Thomas E; Stepanov, Victor G; Fox, George E; van Tongeren, Sandra P; Torres, Clinton; Allen, Jonathan; Jaing, Crystal; Pierson, Duane; Perry, Jay; Koren, Sergey; Phillippy, Adam; Klubnik, Joy; Treangen, Todd J; Rosovitz, M J; Bergman, Nicholas H

2017-01-01

The draft genome sequences of six Bacillus strains, isolated from the International Space Station and belonging to the Bacillus anthracis-B. cereus-B. thuringiensis group, are presented here. These strains were isolated from the Japanese Experiment Module (one strain), U.S. Harmony Node 2 (three

Comparison of antibody and cytokine responses to primary Giardia muris infection in H-2 congenic strains of mice.

Science.gov (United States)

Venkatesan, P; Finch, R G; Wakelin, D

1996-11-01

The course of primary infections with Giardia muris differs between BALB and B10 H-2 congenic strains of mice. In the first 3 weeks of infection, there is a more rapid decline in intestinal trophozoite and fecal cyst counts in B10 strains than in BALB strains. To determine whether this difference could be explained by variation in specific antibody responses, both secretory immunoglobulin A (IgA) and serum antibody responses were compared between these strains. No significant differences in the timing, titer, or specificity of secretory or serum antibodies were found. However, on comparing specific anti-G. muris serum IgG subclass responses, we found that B10 strains produced IgG2a while BALB strains produced IgG1, suggesting differential involvement of T helper 1 and 2 subsets of lymphocytes. When cells harvested from mesenteric lymph nodes were stimulated with concanavalin A in vitro, both gamma interferon and interleukin-5 were secreted by cells from B10 mice, but only interleukin-5 was secreted by cells from BALB/c mice. Specific blockade of gamma interferon by monoclonal antibody administered to B10 mice resulted in an enhanced intensity of infection.

Group B streptococcal metastatic endophthalmitis.

Science.gov (United States)

Nagelberg, H P; Petashnick, D E; To, K W; Woodcome, H A

1994-04-15

Reports of invasive Group B Streptococcus infection in adults with underlying medical conditions have been increasing. Ocular infection with this organism is unusual. Metastatic endophthalmitis in adults caused by this organism has been reported rarely and has only been associated with endocarditis. We encountered two cases of Group B streptococcal metastatic endophthalmitis in adults who did not have endocarditis. These cases reflect the increasing incidence of invasive Group B Streptococcus infection with its varying manifestations. Additionally, they emphasize the importance of considering this pathogen as a cause of metastatic endophthalmitis in adults with predisposing illnesses.

Evaluation of different strains of eri silkworms ( Samia cynthia ricini B ...

African Journals Online (AJOL)

Eri silkworms, Samia cynthia ricini B., is one of the silkworm races under utilization in Ethiopia. However, it has several strains with wide variation in their commercial traits and selection and utilization of best suited strains of this eri silkworm race that adapt to different agro-ecologies will help to increase silk productivity and ...

Sequence analysis of the first C2 subgenogroup strain of enterovirus 71 isolated in Korea.

Science.gov (United States)

Lee, Jung-Ah; Yoon, Young Sil; Hyeon, Ji-Yeon; Yoo, Jung Sik; Lee, Sang-Won; Lee, June-Woo; Lee, Sang-Won

2016-12-01

Enterovirus 71 (EV71) is an important causative agent of hand-foot-and-mouth disease with severe neurological complications, which may lead to death in children. Large outbreaks caused by EV71 have frequently occurred in Asia-Pacific region. In Korea, the outbreaks have been caused by EV71 subgenogroups C3, and C4. Only genogroup C, especially subgenogroup C1, C3, C4, and C5, has been detected by the national enterovirus surveillance system in Korea. This study reports the first isolation of EV71 A1451 strain, which belongs to subgenogroup C2. EV71 was isolated from a Korean patient with meningoencephalitis. Complete genome analysis and phylogenetic analysis was performed to identify the characteristics of the strain. Comparative genome analysis of the A1451 strain indicated that this novel C2 strain is associated with the Taiwan strains, which are recombinant virus combined with subgenogroup C2 and B3. Because the subgenogroup B3 was not previously detected in Korea, the A1451 strain is regarded as an imported recombinant virus. Periodic surveillance of EV71 is required to control the spread of this disease and its introduction from overseas. Copyright © 2016 Elsevier B.V. All rights reserved.

The genome of a Bacillus isolate causing anthrax in chimpanzees combines chromosomal properties of B. cereus with B. anthracis virulence plasmids.

Directory of Open Access Journals (Sweden)

Silke R Klee

Full Text Available Anthrax is a fatal disease caused by strains of Bacillus anthracis. Members of this monophyletic species are non motile and are all characterized by the presence of four prophages and a nonsense mutation in the plcR regulator gene. Here we report the complete genome sequence of a Bacillus strain isolated from a chimpanzee that had died with clinical symptoms of anthrax. Unlike classic B. anthracis, this strain was motile and lacked the four prohages and the nonsense mutation. Four replicons were identified, a chromosome and three plasmids. Comparative genome analysis revealed that the chromosome resembles those of non-B. anthracis members of the Bacillus cereus group, whereas two plasmids were identical to the anthrax virulence plasmids pXO1 and pXO2. The function of the newly discovered third plasmid with a length of 14 kbp is unknown. A detailed comparison of genomic loci encoding key features confirmed a higher similarity to B. thuringiensis serovar konkukian strain 97-27 and B. cereus E33L than to B. anthracis strains. For the first time we describe the sequence of an anthrax causing bacterium possessing both anthrax plasmids that apparently does not belong to the monophyletic group of all so far known B. anthracis strains and that differs in important diagnostic features. The data suggest that this bacterium has evolved from a B. cereus strain independently from the classic B. anthracis strains and established a B. anthracis lifestyle. Therefore we suggest to designate this isolate as "B. cereus variety (var. anthracis".

Clonal relationship among Vibrio cholerae O1 El Tor strains isolated in Somalia.

Science.gov (United States)

Scrascia, Maria; Pugliese, Nicola; Maimone, Francesco; Mohamud, Kadigia A; Grimont, Patrick A D; Materu, Sadiki F; Pazzani, Carlo

2009-03-01

One hundred and three Vibrio cholerae O1 strains, selected to represent the cholera outbreaks which occurred in Somalia in 1998-1999, were characterized by random amplified polymorphic DNA patterns, ribotyping, and antimicrobial susceptibility. All strains showed a unique amplified DNA pattern and 2 closely related ribotypes (B5a and B8a), among which B5a was the more frequently identified. Ninety-one strains were resistant to ampicillin, chloramphenicol, spectinomycin, streptomycin, sulfamethoxazole, and trimethoprim, conferred, except for spectinomycin, by a conjugative plasmid IncC. These findings indicated that the group of strains active in Somalia in the late 1990s had a clonal origin.

[EFFICIENCY OF INTRODUCING CAROTENE PRODUCING STRAINS BACILLUS SP. 1.1 AND B. AMYLOLIQUEFACIENS UCM B-5113 INTO THE CHIKENS DIET].

Science.gov (United States)

Nechypurenko, O O; Kharhota M A; Avdeeva, L V

2015-01-01

It was shown the efficiency of carotene producing strains Bacillus sp. 1.1 and B. amyloliquefaciens UCM B-5113 in the diet of chickens. Also it was detected the lowering of the quantitative content of bacterial genera Enterococcus, Staphylococcus, family Enterobacteriaceae in the gut after eating by chickens cross "H&N Brown Nick" fodder with strains Bacillus sp. 1.1 and B. amyloliquefaciens UCM B-5113 alone and in composition in quantities 1 x 10(10) CFU per 1 g of feed. On the 18th day after introduction of cultures Bacillus sp. 1.1, B. amyloliquefaciens UCM B-5113 and their composition in the diet of poultry we revealed the increasing of body weight by 21.6, 7.6 and 22.0%, respectively, comparesing to controls. Also due to Bacillus sp. 1.1 it was detected the restore of intestinal villous structures, tissues of spleen, liver and heart. We found the additive effect of the composition of the investigated strains of bacteria genus Bacillus to the chickens.

The stability boundary of group-III transition metal diboride ScB 2 (0 0 0 1) surfaces

Science.gov (United States)

Zhao, Hui; Qin, Na

2012-01-01

Experimental observations and theoretical investigations exhibit that a group-IV(V) transition metal diboride (0 0 0 1) surface is terminated with a 1 × 1 TM(B) layer. As to a group-III transition metal diboride, we have investigated the stability boundary of ScB2 (0 0 0 1) surfaces using first principles total energy plane-wave pseudopotential method based on density functional theory. The Mulliken charge population analysis shows that Sc atoms in the second layer cannot provide B atoms in the first layer with sufficient electrons to form a complete graphene-like boron layer. We also found that the charge transfer between the first and the second layer for the B-terminated surface is more than that for Sc-terminated surface. It elucidates the reason that the outermost interlayer spacing contract more strongly in the B-terminated surface than in the Sc-terminated surface. The surface energies of both terminated ScB2 (0 0 0 1) surfaces as a function of the chemical potential of B are also calculated to check the relative stability of the two surface structures.

Penicillin tolerance among Beta-hemolytic streptococci and production of the group carbohydrates, hemolysins, hyaluronidases and deoxyribonucleases

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Cássia C. Avelino

1995-08-01

Full Text Available Penicillin tolerance among 67 strains of beta-hemolytic streptococci was examined by determining the ratio of the minimal bactericidal concentration to the minimal inhibitory concentration as 32 or greater. Tolerance was demonstrated in 15 group A strains and in 11,7, and 4 of groups B, C and G, respectively. Thereafter the effects of a subminimal inhibitory concentration (1/2MIC of penicillin on the bacterial products of four tolerant and four nontolerant strains (two of each Lancefield group were analyzed and compared. The antibiotic caused a marked increase in the expression of the group carbo-hydrates for strains of group B. Penicillin was found to reduce the cell-bound hemolysin activities of the four tolerant strains and to increase the activity of the other (free form of nontolerant groups A, C and G hemolysins. Penicillin caused an increase in the extracellular hyaluronidase activities of one group A and groups B, C and G streptococci. With added antibiotic the production of deoxyribonuclease by tolerant groups A, C and G was greatly enhanced and that of the group B streptococcus was arrested.

A study of single nucleotide polymorphism in the ystB gene of Yersinia enterocolitica strains isolated from various wild animal species.

Science.gov (United States)

Bancerz-Kisiel, Agata; Szczerba-Turek, Anna; Platt-Samoraj, Aleksandra; Michalczyk, Maria; Szweda, Wojciech

2017-03-01

Y. enterocolitica is the causative agent of yersiniosis. The objective of the article was a study of single nucleotide polymorphism in the ystB gene of Y. enterocolitica strains isolated from various wild animal species. High-resolution melting (HRM) analysis was applied to identify single nucleotide polymorphism (SNP) of ystB gene fragments of 88 Y. enterocolitica biotype 1A strains isolated from wild boar, roe deer, red deer and wild ducks. HRM analysis revealed 14 different melting profiles - 4 of them were defined as regular genotypes (G1, G2, G3, G4), whereas 10 as variations. 24 of the examined Y. enterocolitica strains were classified as G1, 18 strains as a G2, 21 strains as a G3, and 15 strains as a G4. Nucleotide sequences classified as G1 revealed 100% similarity with the Y. enterocolitica D88145.1 sequence (NCBI). Analysis of G2 revealed one point mutation - transition T111A. One mutation was also found in G3, but SNP was placed in a different gene region - transition G193A. Two SNPs - transitions G92C and T111A - were identified in G4. Direct sequencing of 10 variations revealed 5 new variants of the ystB nucleotide sequence: V1 - transition G129A (3 strains); V2 - transitions T111A and G193A (2 strains); V3 - transitions C118T and G193A (1 strain); V4 - transitions C141A and G193A (2 strains); and V5 characterized by 19 SNPs: G83A, T93A, A109G, G114T, C116T, A123G, T134C, T142G, T144C, A150C, G162A, T165G, T170G, T174A, T177G, G178A, A179G, A184G and G193A (2 strains). The predominant genotype in isolates from wild ducks was G1; in red deer G2; in wild boar G3; in roe deer G1 and G4. The proposed HRM method could be used to analyze Y. enterocolitica biotype 1A strains isolated from different sources, including humans.

Association of H2A{sup b} with resistance to collagen-induced arthritis in H2-recombinant mouse strains: An allele associated with reduction of several apparently unrelated responses

Energy Technology Data Exchange (ETDEWEB)

Mitchison, N.A.; Brunner, M.C. [Deutsches Rheuma-Forschungszentrum, Berlin (Germany)

1995-02-01

HLA class II alleles can protect against immunological diseases. Seeking an animal model for a naturally occurring protective allele, we screened a panel of H2-congenic and recombinant mouse strains for ability to protect against collagen-induced arthritis. The strains were crossed with the susceptible strain DBA/1, and the F{sub 1} hybrids immunized with cattle and chicken type II collagen. Hybrids having the H2A{sup b} allele displayed a reduced incidence and duration of the disease. They also had a reduced level of pre-disease inflammation, but not of anti-collagen antibodies. The allele is already known to be associated with reduction of other apparently unrelated immune responses, suggesting that some form of functional differentiation may operate that is not exclusively related to epitope-binding. It is suggested that this may reflect allelic variation in the class II major histocompatibility complex promoter region. 42 refs., 7 figs., 1 tab.

Phenotypical characteristics of group B streptococcus in parturients

Directory of Open Access Journals (Sweden)

Jose Antonio Simoes

Full Text Available Colonization by Group B Streptococcus (GBS is highly prevalent among pregnant women, with prevalence rates ranging between 4% and 30%. The infection may be transmitted vertically and may result in serious neonatal consequences. In the period from November 2003 to May 2004, a cross-sectional study was carried out among 316 parturients at the Jundiaí Teaching Hospital to establish the prevalence of genital GBS colonization, to identify the factors associated with colonization and the characteristic phenotypes of these streptococci. Samples from rectal and vaginal areas were collected for selective culture in Todd-Hewitt broth. Susceptibility to 7 antimicrobial agents was tested using the antibiotic diffusion disk technique, and the isolated strains were classified using specific antisera. The prevalence of GBS colonization was 14.6%. No strain was resistant to penicillin, ampicillin, erythromycin or nitrofurantoin. The majority of strains were sensitive to cephalothin. Greatest resistance was to gentamicin (76.1%, followed by clindamycin (17.4%. The most frequent serotype was Ib (23.9%, followed by serotypes II and Ia (19.6% and 17.4%, respectively. There was no correlation between serotype and greater antimicrobial resistance. In conclusion, the prevalence of GBS in parturients was high and penicillin continues to be the drug of choice for intrapartum prophylaxis. The most frequent serotype (Ib found in this study differs from those found in the majority of studies carried out in other countries, revealing the need to identify prevalent serotypes in each region so that specific vaccines can be designed.

Production of fumonisins B2 and B4 in Tolypocladium species

DEFF Research Database (Denmark)

Mogensen, Jesper Mølgaard; Møller, Kirsten Amalie; von Freiesleben, Pernille

2011-01-01

Tolypocladium inflatum is known primarily for its production of the cyclosporines that are used as an immunosuppressive drug. However, we report here the production of the carcinogenic fumonisins B2 and B4 by this biotechnologically relevant fungal genus. These mycotoxins were detected in 11...... strains tested from three species: Tolypocladium inflatum, T. cylindrosporum, and T. geodes. Production of fumonisins by Fusarium spp. and Aspergillus niger is highly medium- and temperature-dependent, so the effect of these parameters on fumonisin production by three T. inflatum strains was studied....... Maximum production was achieved on media with high sugar content incubated at 25–30°C. Since these results demonstrate that fumonisin production could be widespread within the genus Tolypocladium, the potential contamination of commercial cyclosporine preparations with fumonisins needs to be investigated....

The genetic diversity of commensal Escherichia coli strains isolated from nonantimicrobial treated pigs varies according to age group

DEFF Research Database (Denmark)

Ahmed, Shahana; Olsen, John E.; Herrero-Fresno, Ana

2017-01-01

This is the first report on the genetic diversity of commensal E. coli from pigs reared in an antibiotic free production system and belonging to different age groups. The study investigated the genetic diversity and relationship of 900 randomly collected commensal E. coli strains from non......-antimicrobial treated pigs assigned to five different age groups in a Danish farm. Fifty-two unique REP profiles were detected suggesting a high degree of diversity. The number of strains per pig ranged from two to 13. The highest and the lowest degree of diversity were found in the early weaners group (Shannon...... diversity index, H' of 2.22) and piglets (H' of 1.46) respectively. The REP profiles, R1, R7 and R28, were the most frequently observed in all age groups. E. coli strains representing each REP profile and additional strains associated with the dominant profiles were subjected to PFGE and were assigned to 67...

Strain engineering of WS2, WSe2, and WTe2

KAUST Repository

Amin, Bin

2014-01-01

We perform first-principles calculations to investigate the structural, electronic, and vibrational properties of WS2, WSe2, and WTe2 monolayers, taking into account the strong spin orbit coupling. A transition from a direct to an indirect band gap is achieved for compressive strain of 1% for WS2, 1.5% for WSe2, and 2% for WTe 2, while the nature of the band gap remains direct in the case of tensile strain. The size of the band gap passes through a maximum under compressive strain and decreases monotonically under tensile strain. A strong spin splitting is found for the valence band in all three compounds, which is further enhanced by tensile strain. The mobility of the electrons grows along the series WS2 < WSe2 < WTe2. This journal is © the Partner Organisations 2014.

Efficient cell culture system for hepatitis C virus genotype 2B

DEFF Research Database (Denmark)

2014-01-01

The present inventors developed hepatitis C virus 2b/2a intergenotypic recombinants in which the JFH1 structural genes (Core, E1 and E2), p7 and the complete NS2 were replaced by the corresponding genes of the genotype 2b reference strain J8. Sequence analysis of recovered 2b/2a recombinants from 2...

Whole-genome sequence of Escherichia coli serotype O157:H7 strain B6914-ARS

Science.gov (United States)

Escherichia coli serotype O157:H7 strain B6914-MS1 is a Shiga toxin-deficient human fecal isolate obtained by the Centers for Disease Control and Prevention that has been used extensively in applied research studies. Here we report the genome sequence of strain B6914-ARS, a B6914-MS1 clone that has ...

Sweet and bitter taste of ethanol in C57BL/6J and DBA2/J mouse strains.

Science.gov (United States)

Blizard, David A

2007-01-01

Studies of inbred strains of rats and mice have suggested a positive association between strain variations in sweet taste and ethanol intake. However, strain associations by themselves are insufficient to support a functional link between taste and ethanol intake. We used conditioned taste aversion (CTA) to explore the sweet and bitter taste of ethanol and ability to detect sucrose, quinine and ethanol in C57BL/6J (B6) and DBA/2J (D2) mouse strains that are frequently used in alcohol research. The present study showed that C57BL/6J mice generalized taste aversions from sucrose and quinine solutions to 10% ethanol and, reciprocally, aversions to 10% ethanol generalized to each of these solutions presented separately. Only conditioned aversions to quinine generalized to ethanol in the DBA/2J strain but an aversion conditioned to ethanol did not generalize reciprocally to quinine. Thus, considering these two gustatory qualities, 10% ethanol tastes both sweet and bitter to B6 mice but only bitter to D2. Both strains were able to generalize taste aversions across different concentrations of the same compound. B6 were able to detect lower concentrations of quinine than D2 but both strains were able to detect sucrose and (in contrast to previous findings) ethanol at similar concentrations. The strain-dependent gustatory profiles for ethanol may make an important contribution to the understanding of the undoubtedly complex mechanisms influencing high ethanol preference of B6 and pronounced ethanol avoidance of D2 mice.

Isolation and characterization of mutant strains of Escherichia coli altered in H2 metabolism

International Nuclear Information System (INIS)

Lee, J.H.; Patel, P.; Sankar, P.; Shanmugam, K.T.

1985-01-01

A positive selection procedure is described for the isolation of hydrogenase-defective mutant strains of Escherichia coli. Mutant strains isolated by this procedure can be divided into two major classes. Class II mutants produced hydrogenase activity (determined by using a tritium-exchange assay) and formate hydrogenlyase activity but lacked the ability to reduce benzyl viologen or fumarate with H 2 as the electron donor. Class I mutants failed to produce active hydrogenase and hydrogenase-dependent activities. All the mutant strains produced detectable levels of formate dehydrogenase-1 and -2 and fumarate reductase. The mutation in class I mutants mapped near 65 min of the E. coli chromosome, whereas the mutation in class II mutants mapped between srl and cys operons (58 and 59 min, respectively) in the genome. The class II Hyd mutants can be further subdivided into two groups (hydA and hydB) based on the cotransduction characteristics with cys and srl. These results indicate that there are two hyd operons and one hup operon in the E. coli chromosome. The two hyd operons are needed for the production of active hydrogenase, and all three are essential for hydrogen-dependent growth of the cell

Potential of Laceyella sacchari strain B42 crude xylanase in ...

African Journals Online (AJOL)

rajmac

2013-02-06

Feb 6, 2013 ... sacchari strain B42. Maximal xylanase production was achieved at the incubation period of 48 h with ... chemicals for pulp processing and bleaching. The major ... industrial enzyme with great biotechnological application.

Phylogenetic analysis of Hungarian goose parvovirus isolates and vaccine strains.

Science.gov (United States)

Tatár-Kis, Tímea; Mató, Tamás; Markos, Béla; Palya, Vilmos

2004-08-01

Polymerase chain reaction and sequencing were used to analyse goose parvovirus field isolates and vaccine strains. Two fragments of the genome were amplified. Fragment "A" represents a region of VP3 gene, while fragment "B" represents a region upstream of the VP3 gene, encompassing part of the VP1 gene. In the region of fragment "A" the deduced amino acid sequence of the strains was identical, therefore differentiation among strains could be done only at the nucleotide level, which resulted in the formation of three groups: Hungarian, West-European and Asian strains. In the region of fragment "B", separation of groups could be done by both nucleotide and deduced amino acid sequence level. The nucleotide sequences resulted in the same groups as for fragment "A" but with a different clustering pattern among the Hungarian strains. Within the "Hungarian" group most of the recent field isolates fell into one cluster, very closely related or identical to each other, indicating a very slow evolutionary change. The attenuated strains and field isolates from 1979/80 formed a separate cluster. When vaccine strains and field isolates were compared, two specific amino acid differences were found that can be considered as possible markers for vaccinal strains. Sequence analysis of fragment "B" seems to be a suitable method for differentiation of attenuated vaccine strains from virulent strains. Copyright 2004 Houghton Trust Ltd

Repair of damage by ultraviolet radiation in xeroderma pigmentosum cell strains of complementation groups E and F

NARCIS (Netherlands)

Zelle, B.; Berends, F.; Lohman, P.H.M.

1980-01-01

The xeroderma pignemtosum fibroblast strains XP2RO, complementation group E, and XP23OS, group F were compared with normal human primary fibroblasts UV. regard to repair of damage induced by 254-nn UV> In XP2RO cells, repair DNA synthesis, measured by autoradiography (unscheduled DNA synthesis =

Fumonisins B, A and C profile and masking in Fusarium verticillioides strains on fumonisin-inducing and maize-based media.

Science.gov (United States)

Lazzaro, Irene; Falavigna, Claudia; Dall'asta, Chiara; Proctor, Robert H; Galaverna, Gianni; Battilani, Paola

2012-10-01

The production of fumonisin B, A and C and hidden and partially hydrolysed fumonisin occurrence was investigated in 3 strains of Fusarium verticillioides isolated from maize, cultured for 21-45days on malt extract medium at 25°C and 0.955-0.990 water activity (a(w)). Fumonisin A-B and C series were produced by all the strains in all conditions studied, with B-fumonisin≫C-fumonisin>A-fumonisin following a similar trend. The dynamic of fumonisin production was significantly influenced by factors considered and their interaction, with a(w)=0.990 as favourable condition in ITEM 10026 and ITEM 10027. All fumonisins were maximised at 30days incubation in ITEM 10027 and ITEM 1744 and at 45days incubation in ITEM 10026. Partially hydrolysed fumonisins were detected only for the B-group. Hidden fumonisins were never observed in Fusarium cultures grown on malt extract medium but were detected in the additional trial on maize-based medium, suggesting that the masking phenomenon can occur only in a complex matrix. Copyright © 2012 Elsevier B.V. All rights reserved.

Dietary B vitamin needs of strains of pigs with high and moderate lean growth.

Science.gov (United States)

Stahly, T S; Williams, N H; Lutz, T R; Ewan, R C; Swenson, S G

2007-01-01

Ten sets of 5 littermate pigs from each of 2 genetic strains were utilized to determine the impact of the dietary concentration of 5 B vitamins (riboflavin, niacin, pantothenic acid, cobalamin, and folacin) on growth from 9 to 28 kg of BW in pigs with high or moderate capacity for lean growth. All pigs (penned individually) were reared via a segregated, early weaning scheme, so that the lean growth potential of each strain could be expressed. The basal diet provided the 5 test vitamins at concentrations of total and estimated bioavailability equivalent to a minimum of 100 and 70%, respectively, of their estimated requirements (NRC, 1998) for 5- to 10-kg pigs. At a BW of 9 +/- 0.9 kg, pigs within each litter were allotted to the basal diet supplemented with sources of the 5 test vitamins equivalent to an additional 0, 100, 200, 300, or 400% (bioavailable) of the NRC requirements. Pigs from the high lean strain consumed less feed (P vitamin concentrations were increased. However, the dietary B vitamin concentrations needed to optimize G:F were greater (P 470% of NRC, 1998) vs. moderate (270%) lean strain. Based on these data, the dietary needs for 1 or more of the 5 B vitamins are greater than current NRC (1998) estimates, particularly in pigs expressing a high rate of lean tissue growth. The greater need for these vitamins is not associated with greater dietary energy intake or body energy accretion rate but is potentially due to shifts in the predominant metabolic pathways.

The absence of caffeine inhibition of post-replication repair in excision deficient strains of Escherichia coli B and K12

International Nuclear Information System (INIS)

McCulley, C.M.; Johnson, R.C.

1976-01-01

The effect of caffeine on postreplication repair, as seen in alkaline sucrose gradients, conjugation, and ultraviolet light (UV) survival, was studied in excision deficient strains of Escherichia coli K12 and B. A caffeine concentration of 2 mg/ml was chosen for the study which did not inhibit colony formation. Both E. coli K12 AB2500 and E. coli B WWP2 were more sensitive to UV when plated on caffeine plates. Conjugation was not inhibited in the E. coli K12 strain; however, the same procedure confirmed caffeine inhibition in the E. coli B strain. Caffeine did not inhibit postreplication repair in either strain, as determined by sedimentation profile studies of DNA on alkaline sucrose gradients. No strand breakage or degradation was observed in parental or post-UV replicated DNA for as long as 50 min incubation in caffeine. Thus caffeine concentrations that inhibited two recA gene product related phenomena did not cause immediate changes in size of DNA or inhibit the rate of a DNA gap generating postreplication type of DNA repair

Behaviour of filamentary MgB2 wires subjected to tensile stress at 4.2 K

International Nuclear Information System (INIS)

Kováč, P; Kopera, L; Melišek, T; Hušek, I; Rindfleisch, M; Haessler, W

2013-01-01

Different filamentary MgB 2 wires have been subjected to tensile stress at 4.2 K. Stress–strain and critical current versus stress and strain characteristics of wires differing by filament architecture, sheath materials, deformation and heat treatment were measured and compared. It was found that the linear increase of critical current due to the pre-compression effect (ranging from 5% up to ≈20%) is affected by thermal expansion and the strength of used metallic sheaths. The values of irreversible strain ε irr and stress σ irr depend dominantly on the applied outer sheath and its final heat treatment conditions. Consequently, the strain-tolerance of MgB 2 wires is influenced by several parameters and it is difficult to see a clear relation between I c (ε) and σ(ε) characteristics. The lowest ε irr was measured for Monel sheathed wires (0.3–0.6%), medium for GlidCop ® sheath (0.48–0.6%), and the highest ε irr = 0.6–0.9% were obtained for MgB 2 wires reinforced by the stainless steel 316L annealed at temperature between 600 and 800 ° C. The highest ε irr = 0.9% and σ irr = 900 MPa were measured for the work-hardened steel, which is not considerably softened by the heat treatment at 600 ° C/2.5 h. (paper)

Effect of the temperature, strain rate and microstructure on flow and fracture characteristics of Ti-45Al-2Nb-2Mn+0.8vol.% TiB2 XD alloy

Science.gov (United States)

Erice, B.; Pérez-Martín, M. J.; Cendón, D. A.; Gálvez, F.

2012-05-01

A series of quasi-static and dynamic tensile tests at varying temperatures were carried out to determine the mechanical behaviour of Ti-45Al-2Nb-2Mn+0.8vol.% TiB2 XD as-HIPed alloy. The temperature for the tests ranged from room temperature to 850 ∘C. The effect of the temperature on the ultimate tensile strength, as expected, was almost negligible within the selected temperature range. Nevertheless, the plastic flow suffered some softening because of the temperature. This alloy presents a relatively low ductility; thus, a low tensile strain to failure. The dynamic tests were performed in a Split Hopkinson Tension Bar, showing an increase of the ultimate tensile strength due to the strain rate hardening effect. Johnson-Cook constitutive relation was used to model the plastic flow. A post-testing microstructural of the specimens revealed an inhomogeneous structure, consisting of lamellar α2 + γ structure and γ phase equiaxed grains in the centre, and a fully lamellar structure on the rest. The assessment of the duplex-fully lamellar area ratio showed a clear relationship between the microstructure and the fracture behaviour.

The proportion of non-aflatoxigenic strains of the Aspergillus flavus/oryzae complex from meju by analyses of the aflatoxin biosynthetic genes.

Science.gov (United States)

Hong, Seung-Beom; Lee, Mina; Kim, Dae-Ho; Chung, Soo-Hyun; Shin, Hyeon-Dong; Samson, Robert A

2013-12-01

Strains of the Aspergillus flavus/oryzae complex are frequently isolated from meju, a fermented soybean product, that is used as the starting material for ganjang (soy sauce) and doenjang (soybean paste) production. In this study, we examined the aflatoxin producing capacity of A. flavus/oryzae strains isolated from meju. 192 strains of A. flavus/oryzae were isolated from more than 100 meju samples collected from diverse regions of Korea from 2008 to 2011, and the norB-cypA, omtA, and aflR genes in the aflatoxin biosynthesis gene cluster were analyzed. We found that 178 strains (92.7%) belonged to non-aflatoxigenic group (Type I of norB-cypA, IB-L-B-, IC-AO, or IA-L-B- of omtA, and AO type of aflR), and 14 strains (7.3%) belonged to aflatoxin-producible group (Type II of norB-cypA, IC-L-B+/B- or IC-L-B+ of omtA, and AF type of aflR). Only 7 strains (3.6%) in the aflatoxin-producible group produced aflatoxins on Czapek yeast-extract medium. The aflatoxin-producing capability of A. flavus/oryzae strains from other sources in Korea were also investigated, and 92.9% (52/56) strains from air, 93.9% (31/33) strains from rice straw, 91.7% (11/12) strains from soybean, 81.3% (13/16) strains from corn, 82% (41/50) strains from peanut, and 73.2% (41/56) strains from arable soil were included in the non-aflatoxigenic group. The proportion of non-aflatoxigenicity of meju strains was similar to that of strains from soybean, air and rice straw, all of which have an effect on the fermentation of meju. The data suggest that meju does not have a preference for non-aflatoxigenic or aflatoxin-producible strains of A. flavus/oryzae from the environment of meju. The non-aflatoxigenic meju strains are proposed to be named A. oryzae, while the meju strains that can produce aflatoxins should be referred to A. flavus in this study.

Transferable tight-binding model for strained group IV and III-V materials and heterostructures

Science.gov (United States)

Tan, Yaohua; Povolotskyi, Michael; Kubis, Tillmann; Boykin, Timothy B.; Klimeck, Gerhard

2016-07-01

It is critical to capture the effect due to strain and material interface for device level transistor modeling. We introduce a transferable s p3d5s* tight-binding model with nearest-neighbor interactions for arbitrarily strained group IV and III-V materials. The tight-binding model is parametrized with respect to hybrid functional (HSE06) calculations for varieties of strained systems. The tight-binding calculations of ultrasmall superlattices formed by group IV and group III-V materials show good agreement with the corresponding HSE06 calculations. The application of the tight-binding model to superlattices demonstrates that the transferable tight-binding model with nearest-neighbor interactions can be obtained for group IV and III-V materials.

Genome-Wide Transcription Study of Cryptococcus neoformans H99 Clinical Strain versus Environmental Strains.

Directory of Open Access Journals (Sweden)

Elaheh Movahed

Full Text Available The infection of Cryptococcus neoformans is acquired through the inhalation of desiccated yeast cells and basidiospores originated from the environment, particularly from bird's droppings and decaying wood. Three environmental strains of C. neoformans originated from bird droppings (H4, S48B and S68B and C. neoformans reference clinical strain (H99 were used for intranasal infection in C57BL/6 mice. We showed that the H99 strain demonstrated higher virulence compared to H4, S48B and S68B strains. To examine if gene expression contributed to the different degree of virulence among these strains, a genome-wide microarray study was performed to inspect the transcriptomic profiles of all four strains. Our results revealed that out of 7,419 genes (22,257 probes examined, 65 genes were significantly up-or down-regulated in H99 versus H4, S48B and S68B strains. The up-regulated genes in H99 strain include Hydroxymethylglutaryl-CoA synthase (MVA1, Mitochondrial matrix factor 1 (MMF1, Bud-site-selection protein 8 (BUD8, High affinity glucose transporter 3 (SNF3 and Rho GTPase-activating protein 2 (RGA2. Pathway annotation using DAVID bioinformatics resource showed that metal ion binding and sugar transmembrane transporter activity pathways were highly expressed in the H99 strain. We suggest that the genes and pathways identified may possibly play crucial roles in the fungal pathogenesis.

MLVA genotyping of Brucella melitensis and Brucella abortus isolates from different animal species and humans and identification of Brucella suis vaccine strain S2 from cattle in China.

Directory of Open Access Journals (Sweden)

Hai Jiang

Full Text Available In China, brucellosis is an endemic disease and the main sources of brucellosis in animals and humans are infected sheep, cattle and swine. Brucella melitensis (biovars 1 and 3 is the predominant species, associated with sporadic cases and outbreak in humans. Isolates of B. abortus, primarily biovars 1 and 3, and B. suis biovars 1 and 3 are also associated with sporadic human brucellosis. In this study, the genetic profiles of B. melitensis and B. abortus isolates from humans and animals were analyzed and compared by multi-locus variable-number tandem-repeat analysis (MLVA. Among the B. melitensis isolates, the majority (74/82 belonged to MLVA8 genotype 42, clustering in the 'East Mediterranean' group. Two B. melitensis biovar 1 genotype 47 isolates, belonging to the 'Americas' group, were recovered; both were from the Himalayan blue sheep (Pseudois nayaur, a wild animal. The majority of B. abortus isolates (51/70 were biovar 3, genotype 36. Ten B. suis biovar 1 field isolates, including seven outbreak isolates recovered from a cattle farm in Inner Mongolia, were genetically indistinguishable from the vaccine strain S2, based on MLVA cluster analysis. MLVA analysis provided important information for epidemiological trace-back. To the best of our knowledge, this is the first report to associate Brucella cross-infection with the vaccine strain S2 based on molecular comparison of recovered isolates to the vaccine strain. MLVA typing could be an essential assay to improve brucellosis surveillance and control programs.

High-resolution melt PCR analysis for rapid identification of Chlamydia abortus live vaccine strain 1B among C. abortus strains and field isolates.

Science.gov (United States)

Vorimore, Fabien; Cavanna, Noémie; Vicari, Nadia; Magnino, Simone; Willems, Hermann; Rodolakis, Annie; Siarkou, Victoria I; Laroucau, Karine

2012-09-01

We describe a novel high-resolution melt assay that clearly differentiates Chlamydia abortus live vaccine strain 1B from field C. abortus strains and field wild-type isolates based on previously described single nucleotide polymorphisms. This modern genotyping technique is inexpensive, easy to use, and less time-consuming than PCR-RFLP. Copyright © 2012 Elsevier B.V. All rights reserved.

MICROBIOLOGICAL CHARACTERISATION OF Haemophilus influenzae STRAINS ISOLATED FROM PATIENTS WITH INVASIVE AND RESPIRATORY DISEASES

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Tomislav Kostyanev

2010-01-01

Full Text Available A total of 175 H. influenzae strains were collected between 1994 and 2009 from all aged patient groups. The strains were isolated from patients with invasive and community-acquired respiratory tract infections. All strains were identified according to standard microbiological methods. Serotyping was done by a coagglutination test and by molecular PCR capsular genotyping. Beta-lactamase production was determined by the chromogenic cephalosporin test with nitrocephin as substrate. Most of the isolated H. influenzae strains were from children under 5 years of age (57.7%. Overall, 61 strains belonged to serotype b (34.9% by the means of PCR capsular typing, 1 strain was type f, and 113 isolates (64.6% were non-typeable (non-encapsulated H. influenzae. Among the infants and children with meningitis or other invasive infections, aged 2 month to 5 years, all strains, except one, were serotype b. In respiratory tract infections (pneumonia, otitis media, sinusitis and people with chronic pulmonary diseases - exacerbations of COPD, bronchiectasis, cystic fibrosis the most common - 96.5% were non-typeable strains in both groups children and adults. Overall, the prevalence of beta-lactamase production was 19.4%. But, it was much higher for invasive strains from CSF isolates - 37.7%, 25% in blood samples, and 37.5% in otitis media causative strains. Beta-lactamase production was less frequent in respiratory tract isolates - in sputum 13.3% and in URT samples - 2.3%. The rate of beta-lactamase production in CSF isolates has not changed for the last 10 years.PCR capsular genotyping method has to be performed for all non-b-type strains. The implementation of Hib vaccine in our country will be accompanied by a reduction in invasive diseases caused by H. influenzae type b in children, but it is not useful in preventing infections caused by non-typeable H. influenzae strains.

Analysis of the VP2 protein gene of canine parvovirus strains from affected dogs in Japan.

Science.gov (United States)

Soma, Takehisa; Taharaguchi, Satoshi; Ohinata, Tsuyoshi; Ishii, Hiroshi; Hara, Motonobu

2013-04-01

To clarify the evolution of canine parvovirus 2 (CPV-2) that has recently been epidemic in Japan, VP2 gene sequences at positions 3556-4166 were analyzed in 107 CPV-2 strains obtained from rectal swabs of diarrheic dogs from 2009 to 2011. CPV-2b (95 strains) was more frequently detected than CPV-2a (nine strains), while CPV-2c was not detected. Remaining three strains were identified as the original type CPV-2, which should be derived from vaccines. These findings are similar to the previous results involving Japanese strains, suggesting there has been no great change in the recent CPV-2 epidemic in Japan. This epidemic is the same as that in Taiwan. Furthermore, a 324-lle mutant, which has been reported in Korean and Chinese strains, was detected in 66.7% of CPV-2a strains. Copyright © 2012 Elsevier Ltd. All rights reserved.

Representations of the ultrahyperbolic BMS group UHB(2, 2). I. General Results

International Nuclear Information System (INIS)

Melas, Evangelos

2015-01-01

The ordinary Bondi—Metzner—Sachs (BMS) group B is the common asymptotic symmetry group of all radiating, asymptotically flat, Lorentzian space—times. As such, B is the best candidate for the universal symmetry group of General Relativity (G.R.). However, in studying quantum gravity, space—times with signatures other than the usual Lorentzian one, and complex space-times, are frequently considered. Generalisations of B appropriate to these other signatures have been defined earlier. In particular, the generalisation B(2, 2) appropriate to the ultrahyperbolic signature (+,+, —,—) has been described in detail, and the study of its irreducible unitary representations (IRs) of B(2, 2) has been initiated. We continue this programme by introducing a new group UHB(2, 2) in the group theoretical study of ultrahyperbolic G.R. which happens to be a proper subgroup of B(2, 2). In this paper we report on the first general results on the representation theory of UHB(2, 2). In particular the main general results are that the all little groups of UHB(2, 2) are compact and that the Wigner—Mackey's inducing construction is exhaustive despite the fact that UHB(2, 2) is not locally compact in the employed Hilbert topology. (paper)

STREPTOCOQUE BETA HEMOLYTIQUE DU GROUPE B ET ...

African Journals Online (AJOL)

hémolytic streptococcus during pregnancy and its materno-fetal ..... and their newborns. Medscape Women's Health. 1996 Mar; 1(3):2. 21. Centers for Disease Control and Prevention (CDC). Perinatal Group B streptococcal disease after universal ...

First Report of Avian Metapneumovirus Subtype B Field Strain in a Romanian Broiler Flock During an Outbreak of Respiratory Disease.

Science.gov (United States)

Franzo, Giovanni; Tucciarone, Claudia Maria; Enache, Mirel; Bejan, Violeta; Ramon, Gema; Koutoulis, Konstantinos C; Cecchinato, Mattia

2017-06-01

Avian metapneumovirus (aMPV) represents one of the most prevalent diseases of turkey, especially in combination with other pathogens, and its frequency is also increasing among chickens. Despite this evidence, epidemiologic data are poor and scattered, severely preventing control of the disease even in highly developed areas such as Europe. In the present study, the detection and characterization of an aMPV subtype B strain circulating in a vaccinated but symptomatic Romanian broiler flock is reported for the first time. The phylogenetic analysis based on the partial G gene sequence demonstrates the close relationship of the Romanian virus with a group of recently emerged Italian field strains for which vaccine-induced protection was experimentally proven to be partial. These preliminary results allow us to hypothesize the spreading of vaccine-escaping aMPV subtype B strains through Europe and, consequently, dictate the carrying out of a more systematic survey to confirm this theory and enforce adequate countermeasures.

Group B Strep Infection in Newborns

Science.gov (United States)

... Bacterial Core surveillance (ABCs) CDC Streptococcus Laboratory Sepsis Group B Strep Infection in Newborns Language: English Español ( ... Explains the difference between early- and late-onset group B strep diseases in newborns… How it Spreads ...

Electrical characteristics of thermal CVD B-doped Si films on highly strained Si epitaxially grown on Ge(100) by plasma CVD without substrate heating

International Nuclear Information System (INIS)

Sugawara, Katsutoshi; Sakuraba, Masao; Murota, Junichi

2010-01-01

Using an 84% relaxed Ge(100) buffer layer formed on Si(100) by electron cyclotron resonance (ECR) plasma enhanced chemical vapor deposition (CVD), influence of strain upon electrical characteristics of B-doped Si film epitaxially grown on the Ge buffer have been investigated. For the thinner B-doped Si film, surface strain amount is larger than that of the thicker film, for example, strain amount reaches 2.0% for the thickness of 2.2 nm. It is found that the hole mobility is enhanced by the introduction of strain to Si, and the maximum enhancement of about 3 is obtained. This value is higher than that of the usually reported mobility enhancement by strain using Si 1 -x Ge x buffer. Therefore, introduction of strain using relaxed Ge film formed by ECR plasma enhanced CVD is useful to improve future Si-based device performance.

Effects of Participation in Support Groups on Alzheimer’s Family Caregivers’ Strain and Spiritual Wellbeing

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Farahnaz Mohammadi

2011-04-01

Full Text Available Objectives: Since support for family caregivers is crucial in providing care for elderly, this study was conducted to examine the effects of participation in support groups on Alzheimer’s family caregivers’ strain and spiritual wellbeing. Materials and Methods & Materials: In this semi-experimental study, 32 accessible family caregivers of elderly patients with Alzheimer who had at least one year of experience participated. The intervention consisted of a 4-month active participation in educational and emotional supportive sessions related to patient and caregivers care management. At the end of the intervention, the leadership of the groups was transferred to members of the groups. These sessions were conducted in 3 public centers in the community. Caregivers were assessed by caregiving strain and spiritual wellbeing questionnaires at the beginning, at the end of the intervention and 2 months later. Data was analyzed by ANOVA with repeated measurement. P<0.05 was considered statistically significant. Results: In general, 32 accessible family caregivers of elderly Alzheimer patients with at least one year of experience participated in this study. The mean of spiritual wellbeing through three mentioned measurements showed an improvement (26.029, 34.029, 34.471, whereas the care giving strain showed a decreasing trend (40.118, 32.706, 31.265. Findings based on ANOVA-repeated measurement revealed a significantly decrease in care giving strain (P=0.001 and an improvement in spiritual wellbeing (P=0.005. Conclusion: Participation in the support groups as a manifest of empowering helps family caregivers to deal effectively with care giving difficulties. Psychoeducational programs lead to a decreased care giving strain and improve the spiritual wellbeing of the caregivers. Hence, supportive interventions should be considered by policy makers and professional health care providers for elderly people.

Strain distributions and their influence on electronic structures of WSe2-MoS2 laterally strained heterojunctions

Science.gov (United States)

Zhang, Chendong; Li, Ming-Yang; Tersoff, Jerry; Han, Yimo; Su, Yushan; Li, Lain-Jong; Muller, David A.; Shih, Chih-Kang

2018-02-01

Monolayer transition metal dichalcogenide heterojunctions, including vertical and lateral p-n junctions, have attracted considerable attention due to their potential applications in electronics and optoelectronics. Lattice-misfit strain in atomically abrupt lateral heterojunctions, such as WSe2-MoS2, offers a new band-engineering strategy for tailoring their electronic properties. However, this approach requires an understanding of the strain distribution and its effect on band alignment. Here, we study a WSe2-MoS2 lateral heterojunction using scanning tunnelling microscopy and image its moiré pattern to map the full two-dimensional strain tensor with high spatial resolution. Using scanning tunnelling spectroscopy, we measure both the strain and the band alignment of the WSe2-MoS2 lateral heterojunction. We find that the misfit strain induces type II to type I band alignment transformation. Scanning transmission electron microscopy reveals the dislocations at the interface that partially relieve the strain. Finally, we observe a distinctive electronic structure at the interface due to hetero-bonding.

Structural, mechanical, and electronic properties of TaB2, TaB, IrB2, and IrB: First-principle calculations

International Nuclear Information System (INIS)

Zhao Wenjie; Wang Yuanxu

2009-01-01

First-principle calculations were performed to investigate the structural, elastic, and electronic properties of TaB 2 , TaB, IrB 2 , and IrB. The calculated equilibrium structural parameters, shear modulus, and Young's modulus of TaB 2 are well consistent with the available experimental data, and TaB 2 with P6/mmm space group has stronger directional bonding between ions than WB 2 , OsB 2 , IrN 2 , and PtN 2 . For TaB 2 , the hexagonal P6/mmm structure is more stable than the orthorhombic Pmmn one, while for IrB 2 the orthorhombic Pmmn structure is the most stable one. The high shear modulus of P6/mmm phase TaB 2 is mainly due to the strong covalent π-bonding of B-hexagon in the (0001) plane. Such a B-hexagon network can strongly resist against an applied [112-bar0] (0001) shear deformation. Correlation between the hardness and the elastic constants of TaB 2 was discussed. The band structure shows that P6/mmm phase TaB 2 and Pmmn phase IrB 2 are both metallic. The calculations show that both TaB and IrB are elastically stable with the hexagonal P6 3 /mmc structure. - Elastic constant c 44 of TaB 2 is calculated to be 235 GPa. This value is exceptionally high, exceeding those of WB 2 , OsB 2 , WB 4 , OsN 2 , IrN 2 , and PtN 2 .

Role of kinin B1 and B2 receptors in memory consolidation during the aging process of mice.

Science.gov (United States)

Lemos, Mayra Tolentino Resk; Amaral, Fabio Agostini; Dong, Karis Ester; Bittencourt, Maria Fernanda Queiroz Prado; Caetano, Ariadiny Lima; Pesquero, João Bosco; Viel, Tania Araujo; Buck, Hudson Sousa

2010-04-01

Under physiological conditions, elderly people present memory deficit associated with neuronal loss. This pattern is also associated with Alzheimer's disease but, in this case, in a dramatically intensified level. Kinin receptors have been involved in neurodegeneration and increase of amyloid-beta concentration, associated with Alzheimer's disease (AD). Considering these findings, this work evaluated the role of kinin receptors in memory consolidation during the aging process. Male C57Bl/6 (wt), knock-out B1 (koB1) or B2 (koB2) mice (3, 6, 12 and 18-month-old - mo; n=10 per group) were submitted to an acquisition session, reinforcement to learning (24h later: test 1) and final test (7days later: test 2), in an active avoidance apparatus, to evaluate memory. Conditioned avoidance responses (CAR, % of 50 trials) were registered. In acquisition sessions, similar CAR were obtained among age matched animals from all strains. However, a significant decrease in CAR was observed throughout the aging process (3mo: 8.8+/-2.3%; 6mo: 4.1+/-0.6%; 12mo: 2.2+/-0.6%, 18mo: 3.6+/-0.6%, Pprocess. In test 1, as expected, memory retention increased significantly (Pmemory retention. In test 2, 3- and 6-month-old wt and koB1 mice of all ages showed a significant improvement in memory (Pmemory retention. We suggest that, during the aging process, the B1 receptor could be involved in neurodegeneration and memory loss. Nevertheless, the B2 receptor is apparently acting as a neuroprotective factor. Copyright 2009 Elsevier Ltd. All rights reserved.

Emerging clinical experience with vaccines against group B meningococcal disease.

Science.gov (United States)

Wilkins, A L; Snape, M D

2017-08-01

The prevention of paediatric bacterial meningitis and septicaemia has recently entered a new era with the availability of two vaccines against capsular group B meningococcus (MenB). Both of these vaccines are based on sub-capsular proteins of the meningococcus, an approach that overcomes the challenges set by the poorly immunogenic MenB polysaccharide capsule but adds complexity to predicting and measuring the impact of their use. This review describes the development and use of MenB vaccines to date, from the use of outer membrane vesicle (OMV) vaccines in MenB outbreaks around the world, to emerging evidence on the effectiveness of the newly available vaccines. While recent data from the United Kingdom supports the potential for protein-based vaccines to provide direct protection against MenB disease in immunised children, further research is required to understand the breadth and duration of this protection. A more detailed understanding of the impact of immunisation with these vaccines on nasopharyngeal carriage of the meningococcus is also required, to inform both their potential to induce herd immunity and to preferentially select for carriage of strains not susceptible to vaccine-induced antibodies. Although a full understanding of the potential impact of these vaccines will only be possible with this additional information, the availability of new tools to prevent the devastating effect of invasive MenB disease is a significant breakthrough in the fight against childhood sepsis and meningitis. Copyright © 2017 Elsevier Ltd. All rights reserved.

High resolution melting curve analysis as a new tool for rapid identification of canine parvovirus type 2 strains.

Science.gov (United States)

Bingga, Gali; Liu, Zhicheng; Zhang, Jianfeng; Zhu, Yujun; Lin, Lifeng; Ding, Shuangyang; Guo, Pengju

2014-01-01

A high resolution melting (HRM) curve method was developed to identify canine parvovirus type 2 (CPV-2) strains by nested PCR. Two sets of primers, CPV-426F/426R and CPV-87R/87F, were designed that amplified a 52 bp and 53 bp product from the viral VP2 capsid gene. The region amplified by CPV-426F/426R included the A4062G and T4064A mutations in CPV-2a, CPV-2b and CPV-2c. The region amplified by CPV-87F/87R included the A3045T mutation in the vaccine strains of CPV-2 and CPV-2a, CPV-2b and CPV-2c. Faecal samples were obtained from 30 dogs that were CPV antigen-positive. The DNA was isolated from the faecal samples and PCR-amplified using the two sets of primers, and genotyped by HRM curve analysis. The PCR-HRM assay was able to distinguish single nucleotide polymorphisms between CPV-2a, CPV-2b and CPV-2c using CPV-426F/426R. CPV-2a was distinguished from CPV-2b and CPV-2c by differences in the melting temperature. CPV-2b and CPV-2c could be distinguished based on the shape of the melting curve after generating heteroduplexes using a CPV-2b reference sample. The vaccine strains of CPV-2 were identified using CPV-87F/87R. Conventional methods for genotyping CPV strains are labor intensive, expensive or time consuming; the present PCR-based HRM assay might be an attractive alternative. Copyright © 2014 Elsevier Ltd. All rights reserved.

Mutagenesis at the ad-3A and ad-3B loci in haploid UV-sensitive strains of Neurospora crassa. Pt. 6

International Nuclear Information System (INIS)

De Serres, F.J.; Inoue, H.; Schuepbach, M.E.

1983-01-01

Genetic characterization of ad-3B mutants induced in wild-type and UV-sensitive strains has revealed qualitative differences between the spectra of genetic alterations at the molecular level. Ad-3B mutants induced in the two nucleotide excision-repair-deficient strains upr-1 and uvs-2 had significantly lower frequencies of nonpolarized complementation patterns and higher frequencies of noncomplementing mutants than ad-3B mutants induced in the wild-type strain in samples induced by either UV, #betta#-rays, 4NQO or MNNG. In these same samples ad-3B mutants induced in uvs-4, uvs-5 or uvs-6 did not differ significantly from those induced in the wild-type strain. After ICR-170 treatment, ad-3B mutants induced in the UV-sensitive strains did not differ significantly from those induced in wild-type. The comparisons in the present and previous studies demonstrate that the process of mutation-induction in the ad-3 region is under the control of other loci that not only alter mutant recovery quantitatively but also qualitatively. These data have important implications for comparative chemical mutagenesis, since the spectrum of genetic alterations produced by a given agent can be modified markedly as a result of defects in DNA repair. (orig./AJ)

Pressões retais e anais em primigestas ao defecar Rectal and anal straining pressures in primigravidae

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Wilmar Artur Klug

2008-04-01

Full Text Available OBJETIVO: O estudo teve o objetivo de avaliar as mudanças nas pressões do reto e ânus de primigestas ao simular defecação. MÉTODOS: Selecionamos 60 mulheres no Ambulatório de Pré-natal e no de Cirurgia da Santa Casa de São Paulo. Estas formaram quatro grupos de 15: a grupo-controle: nuligestas; b primigestas no 1º trimestre; c primigestas no 2º trimestre; d primigestas no 3º trimestre. Em todas realizamos manometria retal e anal e as seguintes medidas: a pressão retal em repouso; b pressão retal ao esforço de defecação; c pressão anal à defecação. RESULTADOS: Observamos que as pressões retais ao esforço de defecar aumentam em grávidas em menor proporção que nas nuligestas; estas pressões caíram de 53,9 ± 17,9 em nuligestas para 36,3± 19,6, 38,1 ± 16,2 e 30,5 ± 17,0 nos três trimestres. As pressões anais de defecação foram maiores nas nuligestas (46,9± 17,6 que nas gestantes, respectivamente 37,5 ± 15,5, 32,1 ± 6,2 e 32,9 ± 8,7. Houve maior queda das pressões anais na gestação mais avançada, que compensa a dificuldade para elevar a pressão intra-retal de esforço. CONCLUSÃO: A gravidez altera as pressões retais e anais ao simular defecação, diminuindo- as, mas de forma a compensarem-se mutuamente.OBJECTIVE: This study intended to evaluate rectal and anal straining pressures in primigravidae, at simulated defecation. METHODS: The present study is based on 60 women from de Antenatal Care of Santa Casa de Misericórdia - São Paulo. Patients were divided into four groups of 15: a Control group: nuligravidae; b 1st trimester primigravidae; c 2nd trimester primigravidae; d 3rd trimester primigravidae. All patients underwent rectal and anal measurements to obtain: a Resting rectal pressure; b Straining rectal pressure; c Minimal straining anal pressure. RESULTS: Data was analyzed using statistical methods and reached, the same results: it was observed that the straining rectal pressure decreased from 53

Experiences and Future Expectations towards Online Courses--An Empirical Study of the B2C-and B2B-Segments

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Krämer, Andreas; Böhrs, Sandra

2016-01-01

This article explores the future potential for the development of online courses. The findings are based on an empirical study with 3 sample groups: (1) B2C segment in Germany, (2) B2C segment in the United States, and (3) B2B segment (international). In the first step the status quo of the use of e-learning in general and online courses in…

Interplay among solidification, microstructure, residual strain and hot tearing in B206 aluminum alloy

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D’Elia, F., E-mail: f.delia10@gmail.com [Centre for Near-net-shape Processing of Materials, Ryerson University, 101 Gerrard St. East, Toronto, Ontario, Canada M5B 2K3 (Canada); Ravindran, C. [Centre for Near-net-shape Processing of Materials, Ryerson University, 101 Gerrard St. East, Toronto, Ontario, Canada M5B 2K3 (Canada); Sediako, D. [Canadian Neutron Beam Centre, Chalk River Laboratories, Chalk River, Ontario, Canada K0J 1J0 (Canada)

2015-01-29

Hot tearing is a complex phenomenon attributed to alloy solidification, microstructure and stress/strain development within a casting. In this research, the conditions associated with the formation of hot tears in B206 aluminum alloy were investigated. Neutron diffraction strain mapping was carried out on three B206 castings with varying levels of titanium (i.e. unrefined, 0.02 and 0.05 wt%). Titanium additions effectively reduced grain size and transformed grain morphology from coarse dendrites to fine globular grains. Further, thermal analysis suggested that grain refinement delayed the onset of dendrite coherency in B206 and therefore enhanced the duration of bulk liquid metal feeding for the refined casting conditions. As a result, the interactive effects of such factors resulted in a more uniform distribution of strain, and subsequent higher resistance to hot tearing for the grain refined castings.

Probiotic properties of Lactobacillus strains isolated from Tibetan kefir grains.

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Yongchen Zheng

Full Text Available The objective of this study was to evaluate the functional properties of lactic acid bacteria (LAB isolated from Tibetan kefir grains. Three Lactobacillus isolates identified as Lactobacillus acidophilus LA15, Lactobacillus plantarum B23 and Lactobacillus kefiri D17 that showed resistance to acid and bile salts were selected for further evaluation of their probiotic properties. The 3 selected strains expressed high in vitro adherence to Caco-2 cells. They were sensitive to gentamicin, erythromycin and chloramphenicol and resistant to vancomycin with MIC values of 26 µg/ml. All 3 strains showed potential bile salt hydrolase (BSH activity, cholesterol assimilation and cholesterol co-precipitation ability. Additionally, the potential effect of these strains on plasma cholesterol levels was evaluated in Sprague-Dawley (SD rats. Rats in 4 treatment groups were fed the following experimental diets for 4 weeks: a high-cholesterol diet, a high-cholesterol diet plus LA15, a high-cholesterol diet plus B23 or a high-cholesterol diet plus D17. The total cholesterol, triglyceride and low-density lipoprotein cholesterol levels in the serum were significantly (P<0.05 decreased in the LAB-treated rats compared with rats fed a high-cholesterol diet without LAB supplementation. The high-density lipoprotein cholesterol levels in groups B23 and D17 were significantly (P<0.05 higher than those in the control and LA15 groups. Additionally, both fecal cholesterol and bile acid levels were significantly (P<0.05 increased after LAB administration. Fecal lactobacilli counts were significantly (P<0.05 higher in the LAB treatment groups than in the control groups. Furthermore, the 3 strains were detected in the rat small intestine, colon and feces during the feeding trial. The bacteria levels remained high even after the LAB administration had been stopped for 2 weeks. These results suggest that these strains may be used in the future as probiotic starter cultures for

Probiotic Properties of Lactobacillus Strains Isolated from Tibetan Kefir Grains

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Zheng, Yongchen; Lu, Yingli; Wang, Jinfeng; Yang, Longfei; Pan, Chenyu; Huang, Ying

2013-01-01

The objective of this study was to evaluate the functional properties of lactic acid bacteria (LAB) isolated from Tibetan kefir grains. Three Lactobacillus isolates identified as Lactobacillus acidophilus LA15, Lactobacillus plantarum B23 and Lactobacillus kefiri D17 that showed resistance to acid and bile salts were selected for further evaluation of their probiotic properties. The 3 selected strains expressed high in vitro adherence to Caco-2 cells. They were sensitive to gentamicin, erythromycin and chloramphenicol and resistant to vancomycin with MIC values of 26 µg/ml. All 3 strains showed potential bile salt hydrolase (BSH) activity, cholesterol assimilation and cholesterol co-precipitation ability. Additionally, the potential effect of these strains on plasma cholesterol levels was evaluated in Sprague-Dawley (SD) rats. Rats in 4 treatment groups were fed the following experimental diets for 4 weeks: a high-cholesterol diet, a high-cholesterol diet plus LA15, a high-cholesterol diet plus B23 or a high-cholesterol diet plus D17. The total cholesterol, triglyceride and low-density lipoprotein cholesterol levels in the serum were significantly (P<0.05) decreased in the LAB-treated rats compared with rats fed a high-cholesterol diet without LAB supplementation. The high-density lipoprotein cholesterol levels in groups B23 and D17 were significantly (P<0.05) higher than those in the control and LA15 groups. Additionally, both fecal cholesterol and bile acid levels were significantly (P<0.05) increased after LAB administration. Fecal lactobacilli counts were significantly (P<0.05) higher in the LAB treatment groups than in the control groups. Furthermore, the 3 strains were detected in the rat small intestine, colon and feces during the feeding trial. The bacteria levels remained high even after the LAB administration had been stopped for 2 weeks. These results suggest that these strains may be used in the future as probiotic starter cultures for manufacturing

Variations in TcdB activity and the hypervirulence of emerging strains of Clostridium difficile.

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Jordi M Lanis

2010-08-01

Full Text Available Hypervirulent strains of Clostridium difficile have emerged over the past decade, increasing the morbidity and mortality of patients infected by this opportunistic pathogen. Recent work suggested the major C. difficile virulence factor, TcdB, from hypervirulent strains (TcdB(HV was more cytotoxic in vitro than TcdB from historical strains (TcdB(HIST. The current study investigated the in vivo impact of altered TcdB tropism, and the underlying mechanism responsible for the differences in activity between the two forms of this toxin. A combination of protein sequence analyses, in vivo studies using a Danio rerio model system, and cell entry combined with fluorescence assays were used to define the critical differences between TcdB(HV and TcdB(HIST. Sequence analysis found that TcdB was the most variable protein expressed from the pathogenicity locus of C. difficile. In line with these sequence differences, the in vivo effects of TcdB(HV were found to be substantially broader and more pronounced than those caused by TcdB(HIST. The increased toxicity of TcdB(HV was related to the toxin's ability to enter cells more rapidly and at an earlier stage in endocytosis than TcdB(HIST. The underlying biochemical mechanism for more rapid cell entry was identified in experiments demonstrating that TcdB(HV undergoes acid-induced conformational changes at a pH much higher than that of TcdB(HIST. Such pH-related conformational changes are known to be the inciting step in membrane insertion and translocation for TcdB. These data provide insight into a critical change in TcdB activity that contributes to the emerging hypervirulence of C. difficile.

Identification of novel rabbit hemorrhagic disease virus B-cell epitopes and their interaction with host histo-blood group antigens.

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Song, Yanhua; Wang, Fang; Fan, Zhiyu; Hu, Bo; Liu, Xing; Wei, Houjun; Xue, Jiabin; Xu, Weizhong; Qiu, Rulong

2016-02-01

Rabbit haemorrhagic disease, caused by rabbit hemorrhagic disease virus (RHDV), results in the death of millions of adult rabbits worldwide, with a mortality rate that exceeds 90%. The sole capsid protein, VP60, is divided into shell (S) and protruding (P) domains, and the more exposed P domain likely contains determinants for cell attachment and antigenic diversity. Nine mAbs against VP60 were screened and identified. To map antigenic epitopes, a set of partially overlapping and consecutive truncated proteins spanning VP60 were expressed. The minimal determinants of the linear B-cell epitopes of VP60 in the P domain, N(326)PISQV(331), D(338)MSFV(342) and K(562)STLVFNL(569), were recognized by one (5H3), four (1B8, 3D11, 4C2 and 4G2) and four mAbs (1D4, 3F7, 5G2 and 6B2), respectively. Sequence alignment showed epitope D(338)MSFV(342) was conserved among all RHDV isolates. Epitopes N(326)PISQV(331) and K(562)STLVFNL(569) were highly conserved among RHDV G1-G6 and variable in RHDV2 strains. Previous studies demonstrated that native viral particles and virus-like particles (VLPs) of RHDV specifically bound to synthetic blood group H type 2 oligosaccharides. We established an oligosaccharide-based assay to analyse the binding of VP60 and epitopes to histo-blood group antigens (HBGAs). Results showed VP60 and its epitopes (aa 326-331 and 338-342) in the P2 subdomain could significantly bind to blood group H type 2. Furthermore, mAbs 1B8 and 5H3 could block RHDV VLP binding to synthetic H type 2. Collectively, these two epitopes might play a key role in the antigenic structure of VP60 and interaction of RHDV and HBGA.

Regulation of virulence by a two-component system in group B streptococcus.

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Jiang, Sheng-Mei; Cieslewicz, Michael J; Kasper, Dennis L; Wessels, Michael R

2005-02-01

Group B Streptococcus (GBS) is frequently carried in the gastrointestinal or genitourinary tract as a commensal organism, yet it has the potential to cause life-threatening infection in newborn infants, pregnant women, and individuals with chronic illness. Regulation of virulence factor expression may affect whether GBS behaves as an asymptomatic colonizer or an invasive pathogen, but little is known about how such factors are controlled in GBS. We now report the characterization of a GBS locus that encodes a two-component regulatory system similar to CsrRS (or CovRS) in Streptococcus pyogenes. Inactivation of csrR, encoding the putative response regulator, in two unrelated wild-type strains of GBS resulted in a marked increase in production of beta-hemolysin/cytolysin and a striking decrease in production of CAMP factor, an unrelated cytolytic toxin. Quantitative RNA hybridization experiments revealed that these two phenotypes were associated with a marked increase and decrease in expression of the corresponding genes, cylE and cfb, respectively. The CsrR mutant strains also displayed increased expression of scpB encoding C5a peptidase. Similar, but less marked, changes in gene expression were observed in CsrS (putative sensor component) mutants, evidence that CsrR and CsrS constitute a functional two-component system. Experimental infection studies in mice demonstrated reduced virulence of both CsrR and CsrS mutant strains relative to the wild type. Together, these results indicate that CsrRS regulates expression of multiple GBS virulence determinants and is likely to play an important role in GBS pathogenesis.

ITS1/5.8S/ITS2, a Good Marker for Initial Classification of Shiitake Culinary-Medicinal Lentinus edodes (Agaricomycetes) Strains in China.

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Song, Xiao-Xia; Zhao, Yan; Song, Chun-Yan; Li, Chuan-Hua; Song, Ying; Chen, Ming-Jie; Bao, Da-Peng; Tan, Qi

2018-01-01

China is home to rich wild and cultivated strains of Lentinus edodes, an important edible and medicinal mushroom. Artificial selection of L. edodes has a long history, and the widely cultivated strains belong to populations different from those of most wild strains. Internal transcribed spacer (ITS) regions have been used as good markers to identify L. edodes populations. But because ITS regions exhibit incomplete concerted evolution, the use of an ITS to identify L. edodes populations has been questioned. The objective of this study was to determine whether the ITS region is suitable for identifying L. edodes populations and which populations the widely cultivated strains and the most wild strains belong to by investigating intraindividual and differential ITS polymorphisms between 44 cultivars and 44 wild strains of L. edodes in China. Intraindividual ITS polymorphism is common in L. edodes strains, and most strains possessed 2 different ITS sequences, which came from their heterokaryons. The genetic polymorphisms of ITS1, 5.8S, and ITS2 in L. edodes strains are distinct. All strains were divided into one 5.8S type (5.8S-A), 2 ITS1 types (ITS1-A and ITS1-B), and 2 ITS2 types (ITS2-A and ITS2-B), which were subdivided into 2 branches (ITS2-A1 and ITS2-A2; ITS2-B1 and ITS2-B2). ITS1/5.8S/ITS2 could be used as a good marker in preliminary classification of L. edodes strains in China. It not only exhibited classified information of ITS1, 5.8S, and ITS2 for each strain at the same time, it also indicated whether the strain was heterozygous. The 44 cultivated strains were mainly the A/A/A1 type, and the 44 wild strains were mainly the A/A/A2 and other mixed types.

Transferable tight binding model for strained group IV and III-V heterostructures

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Tan, Yaohua; Povolotskyi, Micheal; Kubis, Tillmann; Boykin, Timothy; Klimeck, Gerhard

Modern semiconductor devices have reached critical device dimensions in the range of several nanometers. For reliable prediction of device performance, it is critical to have a numerical efficient model that are transferable to material interfaces. In this work, we present an empirical tight binding (ETB) model with transferable parameters for strained IV and III-V group semiconductors. The ETB model is numerically highly efficient as it make use of an orthogonal sp3d5s* basis set with nearest neighbor inter-atomic interactions. The ETB parameters are generated from HSE06 hybrid functional calculations. Band structures of strained group IV and III-V materials by ETB model are in good agreement with corresponding HSE06 calculations. Furthermore, the ETB model is applied to strained superlattices which consist of group IV and III-V elements. The ETB model turns out to be transferable to nano-scale hetero-structure. The ETB band structures agree with the corresponding HSE06 results in the whole Brillouin zone. The ETB band gaps of superlattices with common cations or common anions have discrepancies within 0.05eV.

Comparison of genetic variations of the SLCO1B1, SLCO1B3, and SLCO2B1 genes among five ethnic groups.

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Namgoong, Suhg; Cheong, Hyun Sub; Kim, Ji On; Kim, Lyoung Hyo; Na, Han Sung; Koh, In Song; Chung, Myeon Woo; Shin, Hyoung Doo

2015-11-01

Organic anion-transporting polypeptide (OATP; gene symbol, SLCO) transporters are generally involved in the uptake of multiple drugs and their metabolites at most epithelial barriers. The pattern of single-nucleotide polymorphisms (SNPs) in these transporters may be determinants of interindividual variability in drug disposition and response. The objective of this study was to define the distribution of SNPs of three SLCO genes, SLCO1B1, SLCO1B3, and SLCO2B1, in a Korean population and other ethnic groups. The study was screened using the Illumina GoldenGate assay for genomic DNA from 450 interethnic subjects, including 11 pharmacogenetic core variants and 76 HapMap tagging SNPs. The genotype distribution of the Korean population was similar to East Asian populations, but significantly different from African American and European American cohorts. These interethnic differences will be useful information for prospective studies, including genetic association and pharmacogenetic studies of drug metabolism by SLCO families. Copyright © 2015 Elsevier B.V. All rights reserved.

Predicted Strain Coverage of a New Meningococcal Multicomponent Vaccine (4CMenB in Spain: Analysis of the Differences with Other European Countries.

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Raquel Abad

Full Text Available A novel meningococcal multicomponent vaccine, 4CMenB (Bexsero®, has been approved in Europe, Canada, Australia and US. The potential impact of 4CMenB on strain coverage is being estimated by using Meningococcal Antigen Typing System (MATS, an ELISA assay which measures vaccine antigen expression and diversity in each strain. Here we show the genetic characterization and the 4CMenB potential coverage of Spanish invasive strains (collected during one epidemiological year compared to other European countries and discuss the potential reasons for the lower estimate of coverage in Spain.A panel of 300 strains, a representative sample of all serogroup B Neisseria meningitidis notified cases in Spain from 2009 to 2010, was characterized by multilocus sequence typing (MLST and FetA variable region determination. 4CMenB vaccine antigens, PorA, factor H binding protein (fHbp, Neisseria Heparin Binding Antigen (NHBA and Neisserial adhesin A (NadA were molecularly typed by sequencing. PorA coverage was assigned to strain with VR2 = 4. The levels of expression and cross-reactivity of fHbp, NHBA and NadA were analyzed using MATS ELISA.Global estimated strain coverage by MATS was 68.67% (95% CI: 47.77-84.59%, with 51.33%, 15.33% and 2% of strains covered by one, two and three vaccine antigens, respectively. The predicted strain coverage by individual antigens was: 42% NHBA, 36.33% fHbp, 8.33% PorA and 1.33% NadA. Coverage within the most prevalent clonal complexes (cc was 70.37% for cc 269, 30.19% for cc 213 and 95.83% for cc 32.Clonal complexes (cc distribution accounts for variations in strain coverage, so that country-by-country investigations of strain coverage and cc prevalence are important. Because the cc distribution could also vary over time, which in turn could lead to changes in strain coverage, continuous detailed surveillance and monitoring of vaccine antigens expression is needed in those countries where the multicomponent vaccine is introduced

Production and Testing of the VITAMIN-B7 Fine-Group and BUGLE-B7 Broad-Group Coupled Neutron/Gamma Cross-Section Libraries Derived from ENDF/B-VII.0 Nuclear Data

Energy Technology Data Exchange (ETDEWEB)

Risner, J. M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wiarda, D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dunn, M. E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Miller, T. M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Peplow, D. E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Patton, B. W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2011-09-30

New coupled neutron-gamma cross-section libraries have been developed for use in light water reactor (LWR) shielding applications, including pressure vessel dosimetry calculations. The libraries, which were generated using Evaluated Nuclear Data File/B Version VII Release 0 (ENDF/B-VII.0), use the same fine-group and broad-group energy structures as the VITAMIN-B6 and BUGLE-96 libraries. The processing methodology used to generate both libraries is based on the methods used to develop VITAMIN-B6 and BUGLE-96 and is consistent with ANSI/ANS 6.1.2. The ENDF data were first processed into the fine-group pseudo-problem-independent VITAMIN-B7 library and then collapsed into the broad-group BUGLE-B7 library. The VITAMIN-B7 library contains data for 391 nuclides. This represents a significant increase compared to the VITAMIN-B6 library, which contained data for 120 nuclides. The BUGLE-B7 library contains data for the same nuclides as BUGLE-96, and maintains the same numeric IDs for those nuclides. The broad-group data includes nuclides which are infinitely dilute and group collapsed using a concrete weighting spectrum, as well as nuclides which are self-shielded and group collapsed using weighting spectra representative of important regions of LWRs. The verification and validation of the new libraries includes a set of critical benchmark experiments, a set of regression tests that are used to evaluate multigroup crosssection libraries in the SCALE code system, and three pressure vessel dosimetry benchmarks. Results of these tests confirm that the new libraries are appropriate for use in LWR shielding analyses and meet the requirements of Regulatory Guide 1.190.

Genes involved in lactose catabolism and organic acid production during growth of Lactobacillus delbrueckii UFV H2b20 in skimmed milk.

Science.gov (United States)

Do Carmo, A P; De Oliveira, M N V; Da Silva, D F; Castro, S B; Borges, A C; De Carvalho, A F; De Moraes, C A

2012-03-01

There are three main reasons for using lactic acid bacteria (LAB) as starter cultures in industrial food fermentation processes: food preservation due to lactic acid production; flavour formation due to a range of organic molecules derived from sugar, lipid and protein catabolism; and probiotic properties attributed to some strains of LAB, mainly of lactobacilli. The aim of this study was to identify some genes involved in lactose metabolism of the probiotic Lactobacillus delbrueckii UFV H2b20, and analyse its organic acid production during growth in skimmed milk. The following genes were identified, encoding the respective enzymes: ldh - lactate dehydrogenase, adhE - Ldb1707 acetaldehyde dehydrogenase, and ccpA-pepR1 - catabolite control protein A. It was observed that L. delbrueckii UFV H2b20 cultivated in different media has the unexpected ability to catabolyse galactose, and to produce high amounts of succinic acid, which was absent in the beginning, raising doubts about the subspecies in question. The phylogenetic analyses showed that this strain can be compared physiologically to L. delbrueckii subsp. bulgaricus and L. delbrueckii subsp. lactis, which are able to degrade lactose and can grow in milk. L. delbrueckii UFV H2b20 sequences have grouped with L. delbrueckii subsp. bulgaricus ATCC 11842 and L. delbrueckii subsp. bulgaricus ATCC BAA-365, strengthening the classification of this probiotic strain in the NCFM group proposed by a previous study. Additionally, L. delbrueckii UFV H2b20 presented an evolutionary pattern closer to that of probiotic Lactobacillus acidophilus NCFM, corroborating the suggestion that this strain might be considered as a new and unusual subspecies among L. delbrueckii subspecies, the first one identified as a probiotic. In addition, its unusual ability to metabolise galactose, which was significantly consumed in the fermentation medium, might be exploited to produce low-browning probiotic Mozzarella cheeses, a desirable property

Mutation profiling of the hepatitis B virus strains circulating in North Indian population.

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Amit Tuteja

Full Text Available AIMS: The aim of this study was to investigate the genomic mutations in the circulating Hepatitis B virus strains causing infection in the Indian population. Further, we wanted to analyze the biological significance of these mutations in HBV mediated disease. METHODS: 222 HBsAg positive patients were enrolled in the study. The genotype and mutation profile was determined for the infecting HBV isolate by sequencing overlapping fragments. These sequences were analyzed by using different tools and compared with previously available HBV sequence information. Mutation Frequency Index (MFI for the Genes and Diagnosis group was also calculated. RESULTS: HBV Genotype D was found in 55% (n = 121 of the patient group and genotype A was found in 30% (n = 66 of samples. The majority (52% of the HBV-infected individuals in the present study were HBeAg-negative in all the age groups studied. Spontaneous drug associated mutations implicated in resistance to antiviral therapy were also identified in about quarter of our patients, which is of therapeutic concern. The MFI approach used in the study indicated that Core peptide was the most conserved region in both genotypes and Surface peptide had highest mutation frequency. Few mutations in X gene (T36A and G50R showed high frequency of association with HCC. A rare recombinant strain of HBV genotype A and D was also identified in the patient group. CONCLUSIONS: HBV genotype D was found out to be most prevalent. More than half of the patients studied had HBeAg negative disease. Core region was found to be most conserved. Drug Associated mutations were detected in 22% of the patient group and T36A and G50R mutations in X gene were found to be associated with HCC.

Attenuation of the goose parvovirus strain B. Laboratory and field trials of the attenuated mutant for vaccination against Derzsy's disease.

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Kisary, J; Derzsy, D; Meszaros, J

1978-07-01

Serial transfer of the goose parvovirus strain B, causal agent of Derzsy's gosling disease, in cultured goose-embryo fibroblast (GEF) resulted in a mutant (designated as Bav) apathogenic for both goose embryos and susceptible goslings. Goose embryos inoculated with the 38th or higher passages of strain B survived the infection, although the virus replicated in their organs. Susceptible goslings survived challenge with the Bav strain without showing symptoms, and developed normally. Only 4.2% of gosling progeny of parents vaccinated twice with strain Bav died after challenge with the virulent strain B goose parvovirus compared with 95% of gosling progeny of unvaccinated parents. Progeny of vaccinated and unvaccinated geese were placed on a farm on which Derzsy's disease was present. During the first month of life mortality was 7.7% in the progeny of vaccinated geese compared with 59.8% in the progeny of the unvaccinated geese. At 8 weeks of age the mean weight of the vaccinated goslings was 20% greater than for the unvaccinated goslings. These results indicate that the attenuated apathogenic Bav mutant is suitable for the immunisation of layers to protect their progeny by passive immunisation against Derzsy's disease.

Genotypic and biological characteristics of non-identified strain of spotted fever group rickettsiae isolated in Crimea.

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Balayeva, N M; Demkin, V V; Rydkina, E B; Ignatovich, V F; Artemiev, M I; Lichoded LYa; Genig, V A

1993-12-01

A strain of rickettsiae, designated Crimea-108, was isolated from ticks Dermacentor marginatus in the Crimea in 1977. Its immunobiological characteristics involve low pathogenicity for experimental animals, moderate infectivity for chick embryos, and antigenic relatedness to spotted fever group (SFG) rickettsiae (R. sibirica, R. conorii, R. akari), especially to R. sibirica. The genotypic characterization of the strain Crimea-108 was carried out in comparison with SFG and typhus group rickettsiae by using restriction fragment length polymorphism (RFLP) analysis and DNA-probe hybridization. The marked similarity was detected between DNA restriction patterns of the strains Crimea-108, R. sibirica and R. conorii, but each of them besides comigrating fragments had specific ones. Genotypic analysis of the strain Crimea-108, the SFG and typhus group rickettsiae by three independent DNA probes, based on R. prowazekii DNA, gave unique hybridization patterns for the Crimea-108 strain with all probes. The obtained data show that the Crimea-108 isolate does not belong to the species of R. sibirica, R. conorii, R. akari. The strain Crimea-108 is a novel strain of SFG rickettsiae for the Crimea region.

Increased expression of clp genes in Lactobacillus delbrueckii UFV H2b20 exposed to acid stress and bile salts.

Science.gov (United States)

Ferreira, A B; De Oliveira, M N V; Freitas, F S; Alfenas-Zerbini, P; Da Silva, D F; De Queiroz, M V; Borges, A C; De Moraes, C A

2013-12-01

The ability to survive in harsh environments is an important criterion to select potential probiotics strains. The objective of this study was to identify and carry out phylogenetic and expression analysis by quantitative real-time PCR of the clpP, clpE, clpL and clpX genes in the probiotic strain Lactobacillus delbrueckii UFV H2b20 exposed to the conditions prevailing in the gastrointestinal tract (GIT). Phylogenetic trees reconstructed by Bayesian inference showed that the L. delbrueckii UFV H2b20 clpP, clpL and clpE genes and the ones from L. delbrueckii ATCC 11842 were grouped. The exposure of cells to MRS broth of pH 3.5 for 30 and 60 min resulted in an increased expression of the four genes. Exposure of the L. delbrueckii UFV H2b20 cells for 30 and 60 min to MRS broth containing 0.1% bile salts increased the expression of the clpP and clpE genes, while the expression level of the clpL and clpX genes increased only after 30 min of exposure. The involvement of the studied genes in the responses to acid stress and bile salts suggests a possible central role of these genes in the survival of L. delbrueckii UFV H2b20 during the passage through the GIT, a characteristic necessary for probiotic strains.

First isolation of a new type of human adenovirus (genotype 79), species Human mastadenovirus B (B2) from sewage water in Japan.

Science.gov (United States)

Yoshitomi, Hideaki; Sera, Nobuyuki; Gonzalez, Gabriel; Hanaoka, Nozomu; Fujimoto, Tsuguto

2017-07-01

Human mastadenoviruses (HAdVs) are highly infectious viral pathogens that survive for prolonged periods in environmental waters. We monitored the presence of HAdVs in sewage waters between April 2014 and March 2015. A total of 27 adenoviral strains were detected in 75% (18/24 in occasion-base) of 24 wastewater collected samples. We identified the types of the strains as HAdV-C2 (n = 5), HAdV-A31 (5), HAdV-C1 (4), HAdV-B3 (4), HAdV-C5 (4), HAdV-B11 (2), P11H34F11 (2), and HAdV-D56 (1). The complete genome sequence of one P11H34F11 (strain T150125) was determined by next-generation sequencing and compared to other genome sequences of HAdV-B strains. The comparisons revealed evidence of a recombination event with breaking point in the hexon encoding region, which evidenced high similarity to HAdV-B34, while half of the rest of the genome showed similarity to HAdV-B11, including regions encoding fiber and E3 region proteins. The penton base encoding region seemed to be a recombinant product of HAdV-B14, -34; however, it was evidenced to be divergent to both as a novel type despite showing low bootstrap to support a new clade. We propose T150125 (P11H34F11) is a strain of a novel genotype, HAdV-79. These results support the usefulness of environmental surveillance approaches to monitor circulating HAdVs including novel types. © 2016 Wiley Periodicals, Inc.

Development of a novel vaccine against canine parvovirus infection with a clinical isolate of the type 2b strain.

Science.gov (United States)

Park, Seon Ah; Park, Seung-Yong; Song, Chang-Seon; Choi, In-Soo; Kim, Hwi Yool; Lee, Joong-Bok; Lee, Nak-Hyung

2012-07-01

In spite of an extensive vaccination program, parvoviral infections still pose a major threat to the health of dogs. We isolated a novel canine parvovirus (CPV) strain from a dog with enteritis. Nucleotide and amino acid sequence analysis of the isolate showed that it is a novel type 2b CPV with asparagine at the 426th position and valine at the 555th position in VP2. To develop a vaccine against CPV infection, we passaged the isolate 4 times in A72 cells. The attenuated isolate conferred complete protection against lethal homologous CPV infection in dogs such that they did not develop any clinical symptoms, and their antibody titers against CPV were significantly high at 7-11 days post infection. These results suggest that the virus isolate obtained after passaging can be developed as a novel vaccine against paroviral infection.

New silicate-germanate Cs2Pb2[(Si0.6Ge0.4)2O7] from the series A2Pb2[B2O7], A = K, Cs, B = Si, Ge with the umbrella-like [PbO3]4- group

Science.gov (United States)

Belokoneva, Elena L.; Morozov, Ivan A.; Volkov, Anatoly S.; Dimitrova, Olga V.; Stefanovich, Sergey Yu.

2018-04-01

New silicate-germanate Cs2Pb2[(Si0.6Ge0.4)2O7] was synthesized in multi-components hydrothermal solution with 20 w.% concentration of Cs2CO3 mineralizer, pH = 10. Novel mixed compound belongs to the structure type A2Pb2[B2O7] previously indicated for powders with A = K, B=Si or Ge. Singe crystal structure determination of Cs2Pb2[(Si0.6Ge0.4)2O7] revealed the need for the correction of the space group of the earlier suggested structural model from P-3 to P-3m1, as well as for the splitting of the Pb-atom position. Umbrella-like groups [PbO3]4- are located between [(Si,Ge)O4]4- tetrahedra in mica-like honeycomb layers and play the role of tetrahedra with the Pb-lone-pair as the forth apex. Crystal chemical comparison revealed similarities and differences with the classical structure type of α-celsian Ba[Al2Si2O8] with the tetrahedral double layer. Recently investigated nonlinear optical acentric borates Pb2(BO3)(NO3) and Pb2(BO3)Cl are both related to this structural type, possessing umbrella-like groups [PbO3]4- and honeycomb layers [Pb2(BO3)]+ with the BO3-triangles on the tetrahedral positions.

Monitoring the ethanol stress response of a sigM deletion strain of B. cereus ATCC 14579.

NARCIS (Netherlands)

Voort, van der M.

2008-01-01

Here, the role of σM and its regulon in stress response and survival of B. cereus ATCC 14579 was assessed by comparative transciptome and phenotypic analysis of this strain and its sigM deletion strain. Exposure of B. cereus ATCC 14579 to a wide range of stresses revealed expression of sigM,

Characterization of plasmids harbouring qnrS1, qnrB2 and qnrB19 genes in Salmonella

NARCIS (Netherlands)

Garcia-Fernandez, A.; Fortini, D.; Veldman, K.T.; Mevius, D.J.; Carattoli, A.

2009-01-01

The aim of this study was to identify and characterize plasmids carrying qnrS1, qnrB2 and qnrB19 genes identified in Salmonella strains from The Netherlands. The identification of plasmids may help to follow the dissemination of these resistance genes in different countries and environments.

Transport properties and exponential n-values of Fe/MgB2 tapes with various MgB2 particle sizes

International Nuclear Information System (INIS)

Lezza, P.; Abaecherli, V.; Clayton, N.; Senatore, C.; Uglietti, D.; Suo, H.L.; Fluekiger, R.

2004-01-01

Fe/MgB 2 tapes have been prepared starting with pre-reacted binary MgB 2 powders. As shown by resistive and inductive measurements, the reduction of particle size to a few microns by ball milling has little influence on B c2 , while the superconducting properties of the individual MgB 2 grains are essentially unchanged. Reducing the particle size causes an enhancement of B irr from 14 to 16 T, while J c has considerably increased at high fields, its slope J c (B) being reduced. At 4.2 K, values of 5.3 x 10 4 and 1.2 x 10 3 A/cm 2 were measured at 3.5 and 10 T, respectively, suggesting a dominant role of the conditions at the grain interfaces. A systematic variation of these conditions at the interfaces is undertaken in order to determine the limit of transport properties for Fe/MgB 2 tapes. The addition of 5% Mg to MgB 2 powder was found to affect neither J c nor B c2 . For the tapes with the highest J c values, very high exponential n factors were measured: n=148, 89 and 17 at 3.5, 5 and 10 T, respectively and measurements of critical current versus applied strain have been performed. The mechanism leading to high transport critical current densities of filamentary Fe/MgB 2 tapes based on MgB 2 particles is discussed

Global co-existence of two evolutionary lineages of parvovirus B19 1a, different in genome-wide synonymous positions.

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Marijke W A Molenaar-de Backer

Full Text Available Parvovirus B19 (B19V can cause infection in humans. To date, three genotypes of B19V, with subtypes, are known, of which genotype 1a is the most prevalent genotype in the Western world. We sequenced the genome of B19V strains of 65 asymptomatic, recently infected Dutch blood donors, to investigate the spatio-temporal distribution of B19V strains, in the years 2003-2009. The sequences were compared to B19V sequences from Dutch patients with fifth disease, and to global B19V sequences as available from GenBank. All Dutch B19V strains belonged to genotype 1a. Phylogenetic analysis of the strains from Dutch blood donors showed that two groups of genotype 1a co-exist. A clear-cut division into the two groups was also found among the B19V strains from Dutch patients, and among the B19V sequences in GenBank. The two groups of genotype 1a co-exist around the world and do not appear to differ in their ability to cause disease. Strikingly, the two groups of B19V predominantly differ in synonymous mutations, distributed throughout the entire genome of B19V. We propose to call the two groups of B19V genotype 1a respectively subtype 1a1 and 1a2.

Genetic Techniques for Manipulation of the Phytosterol Biotransformation Strain Mycobacterium neoaurum NRRL B-3805.

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Loraine, Jessica K; Smith, Margaret C M

2017-01-01

Mycobacterium neoaurum is a saprophytic, soil-dwelling bacterium. The strain NRRL B-3805 converts phytosterols to androst-4-ene-3,17-dione (androstenedione; AD), a precursor of multiple C19 steroids of importance to industry. NRRL B-3805 itself is able to convert AD to other steroid products, including testosterone (Ts) and androst-1,4-diene-3,17-dione (androstadienedione; ADD). However to improve this strain for industrial use, genetic modification is a priority. In this chapter, we describe a range of genetic techniques that can be used for M. neoaurum NRRL B-3805. Methods for transformation, expression, and gene knockouts are presented as well as plasmid maintenance and stability.

Femoral Neck Strain during Maximal Contraction of Isolated Hip-Spanning Muscle Groups

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Saulo Martelli

2017-01-01

Full Text Available The aim of the study was to investigate femoral neck strain during maximal isometric contraction of the hip-spanning muscles. The musculoskeletal and the femur finite-element models from an elderly white woman were taken from earlier studies. The hip-spanning muscles were grouped by function in six hip-spanning muscle groups. The peak hip and knee moments in the model were matched to corresponding published measurements of the hip and knee moments during maximal isometric exercises about the hip and the knee in elderly participants. The femoral neck strain was calculated using full activation of the agonist muscles at fourteen physiological joint angles. The 5%±0.8% of the femoral neck volume exceeded the 90th percentile of the strain distribution across the 84 studied scenarios. Hip extensors, flexors, and abductors generated the highest tension in the proximal neck (2727 με, tension (986 με and compression (−2818 με in the anterior and posterior neck, and compression (−2069 με in the distal neck, respectively. Hip extensors and flexors generated the highest neck strain per unit of joint moment (63–67 με·m·N−1 at extreme hip angles. Therefore, femoral neck strain is heterogeneous and muscle contraction and posture dependent.

aes, the gene encoding the esterase B in Escherichia coli, is a powerful phylogenetic marker of the species

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Tuffery Pierre

2009-12-01

Full Text Available Abstract Background Previous studies have established a correlation between electrophoretic polymorphism of esterase B, and virulence and phylogeny of Escherichia coli. Strains belonging to the phylogenetic group B2 are more frequently implicated in extraintestinal infections and include esterase B2 variants, whereas phylogenetic groups A, B1 and D contain less virulent strains and include esterase B1 variants. We investigated esterase B as a marker of phylogeny and/or virulence, in a thorough analysis of the esterase B-encoding gene. Results We identified the gene encoding esterase B as the acetyl-esterase gene (aes using gene disruption. The analysis of aes nucleotide sequences in a panel of 78 reference strains, including the E. coli reference (ECOR strains, demonstrated that the gene is under purifying selection. The phylogenetic tree reconstructed from aes sequences showed a strong correlation with the species phylogenetic history, based on multi-locus sequence typing using six housekeeping genes. The unambiguous distinction between variants B1 and B2 by electrophoresis was consistent with Aes amino-acid sequence analysis and protein modelling, which showed that substituted amino acids in the two esterase B variants occurred mostly at different sites on the protein surface. Studies in an experimental mouse model of septicaemia using mutant strains did not reveal a direct link between aes and extraintestinal virulence. Moreover, we did not find any genes in the chromosomal region of aes to be associated with virulence. Conclusion Our findings suggest that aes does not play a direct role in the virulence of E. coli extraintestinal infection. However, this gene acts as a powerful marker of phylogeny, illustrating the extensive divergence of B2 phylogenetic group strains from the rest of the species.

The Potency of Dextranase from Arthrobacter sp. Strain B7 as Dental Plaque Removal

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AFAF BAKTIR

2005-12-01

Full Text Available Dextranase of Arthrobacter sp. strain B7 (B7DEX enzyme was characterized in this study. This enzyme hydrolyzed sucrose and dextran, but not other glucans (starch, nigeran, cellulose, -soluble glucan. It also hydrolyzed glucan from dental plaque with the activity of 7.38 + 0.66 U/ml, where the activity toward dextran was 31.88 + 1.24 U/ml. The enzyme exhibited the pH optimum of 7 and the temperature optimum of 50 oC. Its optimum stability was at pH 7 and 50 oC. The enzyme was inhibited by Fe3+, Cu2+, Zn2+, and Ag+, but not by the anionic detergent (SDS and the nonionic detergent (Triton-X. The enzyme was activated by Ca2+, Na+, Mg2+, and saliva.

Vaccination with canine parvovirus type 2 (CPV-2) protects against challenge with virulent CPV-2b and CPV-2c.

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Siedek, Elisabeth M; Schmidt, Holger; Sture, Gordon H; Raue, Rüdiger

2011-01-01

Mutations in canine parvovirus (CPV) field isolates have created concerns regarding the ability of vaccines containing CPV-2 to protect against infection with the newly identified antigenic types CPV-2b and CPV-2c. To address this concern, the efficacy of CPV-2 strain NL-35-D currently in use as a commercial vaccine was demonstrated against an oral challenge with CPV-2b and CPV-2c, respectively. Clinically healthy specific pathogen free Beagle dogs were either vaccinated or treated with water for injection first at 8-9 weeks of age and again at 11-12 weeks of age. All dogs were challenged either with CPV-2b or CPV-2c three weeks after the second vaccination. During the two week period following challenge, clinical signs, white blood cell counts, serology by haemagglutination inhibition (HI) and serum neutralisation tests, and virus shedding by haemagglutination test were assessed. All control dogs developed clinical signs of parvovirosis (including pyrexia and leucopenia) and shed virus. Vaccinated dogs seroconverted (HI titres > or =80), remained healthy throughout the study and shed more than 100 times less virus than controls. In conclusion, vaccination with the low passage, high titre CPV-2 strain NL-35-D cross-protects dogs against virulent challenges with CPV-2b or CPV-2c by preventing disease and substantially reducing viral shedding.

Hypervirulent Chlamydia trachomatis Clinical Strain Is a Recombinant between Lymphogranuloma Venereum (L2) and D Lineages

Science.gov (United States)

Somboonna, Naraporn; Wan, Raymond; Ojcius, David M.; Pettengill, Matthew A.; Joseph, Sandeep J.; Chang, Alexander; Hsu, Ray; Read, Timothy D.; Dean, Deborah

2011-01-01

ABSTRACT Chlamydia trachomatis is an obligate intracellular bacterium that causes a diversity of severe and debilitating diseases worldwide. Sporadic and ongoing outbreaks of lymphogranuloma venereum (LGV) strains among men who have sex with men (MSM) support the need for research on virulence factors associated with these organisms. Previous analyses have been limited to single genes or genomes of laboratory-adapted reference strain L2/434 and outbreak strain L2b/UCH-1/proctitis. We characterized an unusual LGV strain, termed L2c, isolated from an MSM with severe hemorrhagic proctitis. L2c developed nonfusing, grape-like inclusions and a cytotoxic phenotype in culture, unlike the LGV strains described to date. Deep genome sequencing revealed that L2c was a recombinant of L2 and D strains with conserved clustered regions of genetic exchange, including a 78-kb region and a partial, yet functional, toxin gene that was lost with prolonged culture. Indels (insertions/deletions) were discovered in an ftsK gene promoter and in the tarp and hctB genes, which encode key proteins involved in replication, inclusion formation, and histone H1-like protein activity, respectively. Analyses suggest that these indels affect gene and/or protein function, supporting the in vitro and disease phenotypes. While recombination has been known to occur for C. trachomatis based on gene sequence analyses, we provide the first whole-genome evidence for recombination between a virulent, invasive LGV strain and a noninvasive common urogenital strain. Given the lack of a genetic system for producing stable C. trachomatis mutants, identifying naturally occurring recombinants can clarify gene function and provide opportunities for discovering avenues for genomic manipulation. PMID:21540364

Strain distributions and their influence on electronic structures of WSe2–MoS2 laterally strained heterojunctions

KAUST Repository

Zhang, Chendong

2018-01-12

Monolayer transition metal dichalcogenide heterojunctions, including vertical and lateral p–n junctions, have attracted considerable attention due to their potential applications in electronics and optoelectronics. Lattice-misfit strain in atomically abrupt lateral heterojunctions, such as WSe2–MoS2, offers a new band-engineering strategy for tailoring their electronic properties. However, this approach requires an understanding of the strain distribution and its effect on band alignment. Here, we study a WSe2–MoS2 lateral heterojunction using scanning tunnelling microscopy and image its moiré pattern to map the full two-dimensional strain tensor with high spatial resolution. Using scanning tunnelling spectroscopy, we measure both the strain and the band alignment of the WSe2–MoS2 lateral heterojunction. We find that the misfit strain induces type II to type I band alignment transformation. Scanning transmission electron microscopy reveals the dislocations at the interface that partially relieve the strain. Finally, we observe a distinctive electronic structure at the interface due to hetero-bonding.

Strain distributions and their influence on electronic structures of WSe2–MoS2 laterally strained heterojunctions

KAUST Repository

Zhang, Chendong; Li, Ming-yang; Tersoff, Jerry; Han, Yimo; Su, Yushan; Li, Lain-Jong; Muller, David A.; Shih, Chih-Kang

2018-01-01

Monolayer transition metal dichalcogenide heterojunctions, including vertical and lateral p–n junctions, have attracted considerable attention due to their potential applications in electronics and optoelectronics. Lattice-misfit strain in atomically abrupt lateral heterojunctions, such as WSe2–MoS2, offers a new band-engineering strategy for tailoring their electronic properties. However, this approach requires an understanding of the strain distribution and its effect on band alignment. Here, we study a WSe2–MoS2 lateral heterojunction using scanning tunnelling microscopy and image its moiré pattern to map the full two-dimensional strain tensor with high spatial resolution. Using scanning tunnelling spectroscopy, we measure both the strain and the band alignment of the WSe2–MoS2 lateral heterojunction. We find that the misfit strain induces type II to type I band alignment transformation. Scanning transmission electron microscopy reveals the dislocations at the interface that partially relieve the strain. Finally, we observe a distinctive electronic structure at the interface due to hetero-bonding.

Efficiency of B-mode Ultrasound and Strain Elastography in Differentiating Between Benign and Malignant Cervical Lymph Nodes.

Science.gov (United States)

Turgut, Eser; Celenk, Cetin; Tanrivermis Sayit, Asli; Bekci, Tumay; Gunbey, Hediye Pinar; Aslan, Kerim

2017-09-01

The purpose of this study was to evaluate the diagnostic accuracy and efficiency of ultrasonography (US), especially when combined with strain elastography (SE), in differentiating between benign and malignant cervical lymph nodes (LNs). Forty-one LNs were examined by B-mode US, power Doppler US, and SE. The following imaging features were analyzed: shape, echogenicity, echogenic hilum, calcification, intranodal vascular pattern, elasticity scores (5 categories), and strain ratio. The average strain ratio was calculated as the mean strain of the adjacent sternocleidomastoid muscle divided by the mean strain of the target LN. The results of the US and SE features were compared with the histopathologic findings. The imaging features that were significantly associated with malignant LNs were an increased short-to-long axis diameter ratio, abnormal or absence of hilum, microcalcification, type 2-3-4 vascularity, 3-4-5 elasticity scores, and a high level of strain ratio (P benign and malignant LNs. Strain elastography is useful in differentiating between benign and malignant cervical LNs, thereby informing decisions to perform a biopsy and/or surgery, and facilitating follow-up.

Phenotypic and genotypic characterization of Brucella strains isolated from autochthonous livestock reveals the dominance of B. abortus biovar 3a in Nigeria.

Science.gov (United States)

Bertu, Wilson J; Ducrotoy, Marie J; Muñoz, Pilar M; Mick, Virginie; Zúñiga-Ripa, Amaia; Bryssinckx, Ward; Kwaga, Jacob K P; Kabir, Junaid; Welburn, Susan C; Moriyón, Ignacio; Ocholi, Reuben A

2015-10-22

Brucellosis is a worldwide widespread zoonosis caused by bacteria of the genus Brucella. Control of this disease in a given area requires an understanding of the Brucella species circulating in livestock and humans. However, because of the difficulties intrinsic to Brucella isolation and typing, such data are scarce for resource-poor areas. The paucity of bacteriological data and the consequent imperfect epidemiological picture are particularly critical for Sahelian and Sub-Sahara African countries. Here, we report on the characterization of 34 isolates collected between 1976 and 2012 from cattle, sheep and horses in Nigeria. All isolates were identified as Brucella abortus by Bruce-ladder PCR and assigned to biovar 3 by conventional typing. Further analysis by enhanced AMOS-ERY PCR showed that all of them belonged to the 3a sub-biovar, and MLVA analysis grouped them in a cluster clearly distinct from that formed by European B. abortus biovar 3b strains. Nevertheless, MLVA detected heterogeneity within the Nigerian biovar 3a strains. The close genetic profiles of the isolates from cattle, sheep and horses, suggest that, at least in some parts of Nigeria, biovar 3a circulates among animal species that are not the preferential hosts of B. abortus. Consistent with previous genetic analyses of 7 strains from Ivory Cost, Gambia and Togo, the analysis of these 34 Nigerian strains supports the hypothesis that the B. abortus biovar 3a lineage is dominant in West African countries. Copyright © 2015 Elsevier B.V. All rights reserved.

Bismuth-boron multiple bonding in BiB_2O"- and Bi_2B"-

International Nuclear Information System (INIS)

Jian, Tian; Cheung, Ling Fung; Chen, Teng-Teng; Wang, Lai-Sheng

2017-01-01

Despite its electron deficiency, boron is versatile in forming multiple bonds. Transition-metal-boron double bonding is known, but boron-metal triple bonds have been elusive. Two bismuth boron cluster anions, BiB_2O"- and Bi_2B"-, containing triple and double B-Bi bonds are presented. The BiB_2O"- and Bi_2B"- clusters are produced by laser vaporization of a mixed B/Bi target and characterized by photoelectron spectroscopy and ab initio calculations. Well-resolved photoelectron spectra are obtained and interpreted with the help of ab initio calculations, which show that both species are linear. Chemical bonding analyses reveal that Bi forms triple and double bonds with boron in BiB_2O"- ([Bi≡B-B≡O]"-) and Bi_2B"- ([Bi=B=Bi]"-), respectively. The Bi-B double and triple bond strengths are calculated to be 3.21 and 4.70 eV, respectively. This is the first experimental observation of Bi-B double and triple bonds, opening the door to design main-group metal-boron complexes with multiple bonding. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Genomic analysis reveals the molecular basis for capsule loss in the group B Streptococcus population.

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Roberto Rosini

Full Text Available The human and bovine bacterial pathogen Streptococcus agalactiae (Group B Streptococcus, GBS expresses a thick polysaccharide capsule that constitutes a major virulence factor and vaccine target. GBS can be classified into ten distinct serotypes differing in the chemical composition of their capsular polysaccharide. However, non-typeable strains that do not react with anti-capsular sera are frequently isolated from colonized and infected humans and cattle. To gain a comprehensive insight into the molecular basis for the loss of capsule expression in GBS, a collection of well-characterized non-typeable strains was investigated by genome sequencing. Genome based phylogenetic analysis extended to a wide population of sequenced strains confirmed the recently observed high clonality among GBS lineages mainly containing human strains, and revealed a much higher degree of diversity in the bovine population. Remarkably, non-typeable strains were equally distributed in all lineages. A number of distinct mutations in the cps operon were identified that were apparently responsible for inactivation of capsule synthesis. The most frequent genetic alterations were point mutations leading to stop codons in the cps genes, and the main target was found to be cpsE encoding the portal glycosyl transferase of capsule biosynthesis. Complementation of strains carrying missense mutations in cpsE with a wild-type gene restored capsule expression allowing the identification of amino acid residues essential for enzyme activity.

SURVEILLANCE of CARBAPENEM NON-SUSCEPTIBLE GRAM NEGATIVE STRAINS and CHARACTERIZATION of CARBAPENEMASES of CLASSES A, B and D in a LEBANESE HOSPITAL.

Science.gov (United States)

Hammoudi, Dalal; Moubareck, Carole Ayoub; Kanso, Abeer; Nordmann, Patrice; Sarkis, Dolla Karam

2015-01-01

The production of carbapenem-hydrolyzing enzymes has been recognized as one of the most currently relevant resistance mechanisms in gram negative bacterial isolates, and is being detected in various countries. In Lebanon, carbapenem resistance was studied among gram negative pathogens collected from a university hospital from January to June of years 2011 and 2012. All isolates were subjected to phenotypic tests including antibiotic susceptibility, cloxacillin effect, modified Hodge test, and Etest for metallo-β-lactamase detection. They were also subjected to genotyping by PCR sequencing to characterize β-lactamases. Between January and June 2011, 48 carbapenem non-susceptible strains were collected. Of these, one Klebsiella pneumoniae harbored OXA-48 and insertion sequence IS 1999; four Acinetobacter baumanni harbored simultaneously OXA-23 and GES-11, and three Pseudomonas harbored VIM-2 carbapenemase. Between January and June 2012, 100 carbapenem non-susceptible strains were collected. Of these, one K. pneumoniae harbored simultaneously OXA-48, IS 1999, and an acquired AmpC of the ACC group; four Serratia marcescens harbored OXA-48, while among eight A. baumannii, one strain co-harbored OXA-23 and GES-11, six harbored OXA-23 and one OXA-24. Fifteen P, aeruginosa and two Pseudomonas species harbored VIM-2; two P. aeruginosa strains produced IMP-1 and two others IMP-2. This epidemiological survey demonstrates the presence of carbapenemases of Ambler classes A, B, and D in a Lebanese hospital and indicates increase in the number and variety of such enzymes.

First results on the representation theory of the Ultrahyperbolic BMS group UHB(2, 2)

International Nuclear Information System (INIS)

Melas, Evangelos

2016-01-01

The Bondi–Metzner–Sachs (BMS) group B is the common asymptotic group of all asymptotically flat (lorentzian) space–times, and is the best candidate for the universal symmetry group of General Relativity (G.R.). B admits generalizations to real space–times of any signature, to complex space–times, and supersymmetric generalizations for any space— time dimension. With this motivation McCarthy constructed the strongly continuous unitary irreducible representations (IRs) of B some time ago, and he identified B(2,2) as the generalization of B appropriate to the to the ultrahyperbolic signature (+,+,−,−) and asymptotic flatness in null directions. We continue this programme by introducing a new group UHB(2, 2) in the group theoretical study of ultrahyperbolic G.R. which happens to be a proper subgroup of B(2, 2). We report on the first general results on the representation theory of UHB(2, 2). In particular the main general results are that the all little groups of UHB(2, 2) are compact and that the Wigner–Mackeys inducing construction is exhaustive despite the fact that UHB(2, 2) is not locally compact in the employed Hilbert topology. (paper)

Characterization of European Yersinia enterocolitica 1A strains using restriction fragment length polymorphism and multilocus sequence analysis.

Science.gov (United States)

Murros, A; Säde, E; Johansson, P; Korkeala, H; Fredriksson-Ahomaa, M; Björkroth, J

2016-10-01

Yersinia enterocolitica is currently divided into two subspecies: subsp. enterocolitica including highly pathogenic strains of biotype 1B and subsp. palearctica including nonpathogenic strains of biotype 1A and moderately pathogenic strains of biotypes 2-5. In this work, we characterized 162 Y. enterocolitica strains of biotype 1A and 50 strains of biotypes 2-4 isolated from human, animal and food samples by restriction fragment length polymorphism using the HindIII restriction enzyme. Phylogenetic relatedness of 20 representative Y. enterocolitica strains including 15 biotype 1A strains was further studied by the multilocus sequence analysis of four housekeeping genes (glnA, gyrB, recA and HSP60). In all the analyses, biotype 1A strains formed a separate genomic group, which differed from Y. enterocolitica subsp. enterocolitica and from the strains of biotypes 2-4 of Y. enterocolitica subsp. palearctica. Based on these results, biotype 1A strains considered nonpathogenic should not be included in subspecies palearctica containing pathogenic strains of biotypes 2-5. Yersinia enterocolitica strains are currently divided into six biotypes and two subspecies. Strains of biotype 1A, which are phenotypically and genotypically very heterogeneous, are classified as subspecies palearctica. In this study, European Y. enterocolitica 1A strains isolated from both human and nonhuman sources were characterized using restriction fragment length polymorphism and multilocus sequence analysis. The European biotype 1A strains formed a separate group, which differed from strains belonging to subspecies enterocolitica and palearctica. This may indicate that the current division between the two subspecies is not sufficient considering the strain diversity within Y. enterocolitica. © 2016 The Society for Applied Microbiology.

SEM and TEM characterization of the microstructure of post-compressed TiB2/2024Al composite.

Science.gov (United States)

Guo, Q; Jiang, L T; Chen, G Q; Feng, D; Sun, D L; Wu, G H

2012-02-01

In the present work, 55 vol.% TiB(2)/2024Al composites were obtained by pressure infiltration method. Compressive properties of 55 vol.% TiB(2)/2024Al composite under the strain rates of 10(-3) and 1S(-1) at different temperature were measured and microstructure of post-compressed TiB(2)/2024Al composite was characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM). No trace of Al(3)Ti compound flake was found. TiB(2)-Al interface was smooth without significant reaction products, and orientation relationships ( [Formula: see text] and [Formula: see text] ) were revealed by HRTEM. Compressive strength of TiB(2)/2024Al composites decreased with temperature regardless of strain rates. The strain-rate-sensitivity of TiB(2)/2024Al composites increased with the increasing temperature. Fracture surface of specimens compressed at 25 and 250°C under 10(-3)S(-1) were characterized by furrow. Under 10(-3)S(-1), high density dislocations were formed in Al matrix when compressed at 25°C and dynamic recrystallization occurred at 250°C. Segregation of Mg and Cu on the subgrain boundary was also revealed at 550°C. Dislocations, whose density increased with temperature, were formed in TiB(2) particles under 1S(-1). Deformation of composites is affected by matrix, reinforcement and strain rate. Copyright © 2011 Elsevier Ltd. All rights reserved.

The frequency of genes encoding three putative group B streptococcal virulence factors among invasive and colonizing isolates

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Borchardt Stephanie M

2006-07-01

Full Text Available Abstract Background Group B Streptococcus (GBS causes severe infections in very young infants and invasive disease in pregnant women and adults with underlying medical conditions. GBS pathogenicity varies between and within serotypes, with considerable variation in genetic content between strains. Three proteins, Rib encoded by rib, and alpha and beta C proteins encoded by bca and bac, respectively, have been suggested as potential vaccine candidates for GBS. It is not known, however, whether these genes occur more frequently in invasive versus colonizing GBS strains. Methods We screened 162 invasive and 338 colonizing GBS strains from different collections using dot blot hybridization to assess the frequency of bca, bac and rib. All strains were defined by serotyping for capsular type, and frequency differences were tested using the Chi square test. Results Genes encoding the beta C protein (bac and Rib (rib occurred at similar frequencies among invasive and colonizing isolates, bac (20% vs. 23%, and rib (28% vs. 20%, while the alpha (bca C protein was more frequently found in colonizing strains (46% vs, invasive (29%. Invasive strains were associated with specific serotype/gene combinations. Conclusion Novel virulence factors must be identified to better understand GBS disease.

Variations in the occurrence of specific rpoB mutations in rifampicin-resistant Mycobacterium tuberculosis isolates from patients of different ethnic groups in Kuwait.

Science.gov (United States)

Ahmad, Suhail; Al-Mutairi, Noura M; Mokaddas, Eiman

2012-05-01

Frequency of resistance-conferring mutations vary among isoniazid- and ethambutol-resistant Mycobacterium tuberculosis isolates obtained from patients of various ethnic groups. This study was aimed to determine the occurrence of specific rpoB mutations in rifampicin-resistant M. tuberculosis isolates from tuberculosis patients of various ethnic groups in Kuwait. Rifampicin-resistant M. tuberculosis isolates (n=119) from South Asian (n=55), Southeast Asian (n=23), Middle Eastern (n=39) and other (n=2) patients and 107 rifampicin-susceptible isolates were tested. Mutations in rpoB were detected by DNA sequencing. Polymorphisms at katG463 and gyrA95 were detected by PCR-RFLP for genetic group assignment. None of rifampicin-susceptible but 116 of 119 rifampicin-resistant isolates showed rpoB mutation(s). Mutations among isolates from South Asian patients were distributed at rpoB516 (20%), rpoB526 (24%) and rpoB531 (27%) while 78 and 51 per cent of isolates from Southeast Asian and Middle Eastern patients, respectively, contained a mutated rpoB531. All isolates with rpoB N-terminal and cluster II mutations were obtained from Middle Eastern and South Asian patients. Most isolates from South Asian (84%) and Southeast Asian (70%) patients belonged to genetic group I while nearly all remaining isolates belonged to genetic group II. Isolates from Middle Eastern patients were distributed among genetic group I (46%), genetic group II (33%) and genetic group III (21%). The occurrence of specific rpoB mutations varied considerably in rifampicin-resistant M. tuberculosis isolates obtained from patients of different ethnic groups within the same country. The present data have important implications for designing region-specific rapid methods for detecting majority of rifampicin-resistant strains.

Comparative analyses of pandemic H1N1 and seasonal H1N1, H3N2, and influenza B infections depict distinct clinical pictures in ferrets.

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Stephen S H Huang

Full Text Available Influenza A and B infections are a worldwide health concern to both humans and animals. High genetic evolution rates of the influenza virus allow the constant emergence of new strains and cause illness variation. Since human influenza infections are often complicated by secondary factors such as age and underlying medical conditions, strain or subtype specific clinical features are difficult to assess. Here we infected ferrets with 13 currently circulating influenza strains (including strains of pandemic 2009 H1N1 [H1N1pdm] and seasonal A/H1N1, A/H3N2, and B viruses. The clinical parameters were measured daily for 14 days in stable environmental conditions to compare clinical characteristics. We found that H1N1pdm strains had a more severe physiological impact than all season strains where pandemic A/California/07/2009 was the most clinically pathogenic pandemic strain. The most serious illness among seasonal A/H1N1 and A/H3N2 groups was caused by A/Solomon Islands/03/2006 and A/Perth/16/2009, respectively. Among the 13 studied strains, B/Hubei-Wujiagang/158/2009 presented the mildest clinical symptoms. We have also discovered that disease severity (by clinical illness and histopathology correlated with influenza specific antibody response but not viral replication in the upper respiratory tract. H1N1pdm induced the highest and most rapid antibody response followed by seasonal A/H3N2, seasonal A/H1N1 and seasonal influenza B (with B/Hubei-Wujiagang/158/2009 inducing the weakest response. Our study is the first to compare the clinical features of multiple circulating influenza strains in ferrets. These findings will help to characterize the clinical pictures of specific influenza strains as well as give insights into the development and administration of appropriate influenza therapeutics.

Antimicrobial Activity of Allicin against Colonizing Group B Streptococci Isolated from Pregnant Women in Ardabil, Iran

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Elham Jannati

2014-06-01

Full Text Available Background and Objectives: Group B streptococci (GBS are the major cause of neonatal and maternal infections. They are susceptible to penicillin, ampicillin and first-generation cephalosporins. However, resistance to other antibiotics such as erythromycin and clindamycin is common among GBS strains. The aim of this study was to evaluate the antimicrobial activity of allicin against colonizing GBS strains in vitro.   Methods: Garlic extract was prepared and allicin was purified using semi-preparative HPLC procedure. Minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC of allicin were determined for 52 GBS strains using microdilution method in Todd Hewitt broth medium.   Results: MIC of allicin was 64-128 µg/mL (MIC90 = 128 and MBC of allicin was 128 to 512µg/mL (MBC90 = 256 for GBS strains.   Conclusion: The results of this study showed that allicin can inhibit growth of GBS in vitro. Further studies on allicin might be worthy of evaluation as a therapeutic agent in treatment of GBS infections.

Different evolutionary trends of swine H1N2 influenza viruses in Italy compared to European viruses.

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Moreno, Ana; Gabanelli, Elena; Sozzi, Enrica; Lelli, Davide; Chiapponi, Chiara; Ciccozzi, Massimo; Zehender, Gianguglielmo; Cordioli, Paolo

2013-12-01

European H1N2 swine influenza viruses (EU H1N2SIVs) arose from multiple reassortment events among human H1N1, human H3N2, and avian influenza viruses. We investigated the evolutionary dynamics of 53 Italian H1N2 strains by comparing them with EU H1N2 SIVs. Hemagglutinin (HA) phylogeny revealed Italian strains fell into four groups: Group A and B (41 strains) had a human H1 similar to EU H1N2SIVs, which probably originated in 1986. However Group B (38 strains) formed a subgroup that had a two-amino acid deletion at positions 146/147 in HA. Group C (11 strains) contained an avian H1 that probably originated in 1996, and Group D (1 strain) had an H1 characteristic of the 2009 pandemic strain. Neuraminidase (NA) phylogeny suggested a series of genomic reassortments had occurred. Group A had an N2 that originated from human H3N2 in the late 1970s. Group B had different human N2 that most likely arose from a reassortment with the more recent human H3N2 virus, which probably occurred in 2000. Group C had an avian-like H1 combined with an N2 gene from one of EU H1N2SIVs, EU H3N2SIVs or Human H3N2. Group D was part of the EU H3N2SIVs clade. Although selection pressure for HA and NA was low, several positively selected sites were identified in both proteins, some of which were antigenic, suggesting selection influenced the evolution of SIV. The data highlight different evolutionary trends between European viruses and currently circulating Italian B strains and show the establishment of reassortant strains involving human viruses in Italian pigs.

Stimulation of protective antibodies against type Ia and Ib group B streptococci by a type Ia polysaccharide-tetanus toxoid conjugate vaccine.

OpenAIRE

Wessels, M R; Paoletti, L C; Rodewald, A K; Michon, F; DiFabio, J; Jennings, H J; Kasper, D L

1993-01-01

Antisera elicited by type Ia group B streptococci (GBS) contain antibodies that react with both type Ia and type Ib strains. Previous studies suggested that antibodies elicited by type Ia organisms recognized a carbohydrate antigen or epitope common to Ia and Ib strains. We now report the synthesis and immunogenicity testing of a type Ia polysaccharide-tetanus toxoid (Ia-TT) conjugate vaccine. Ia-TT elicited type Ia polysaccharide-specific immunoglobulin G antibodies in all three of the rabbi...

High-temperature deformation of B2 NiAl-base alloys

International Nuclear Information System (INIS)

Lee, I.G.; Ghosh, A.K.

1994-01-01

The high-temperature deformation behavior of three rapidly solidified and processed NiAl-base alloys--NiAl, NiAl containing 2 pct TiB 2 , and NiAl containing 4 pct HfC--have been studied and their microstructural and textural changes during deformation characterized. Compressions tests were conducted at 1,300 and 1,447 K at strain rates ranging from 10 -6 to 10 -2 s -1 . HfC-containing material showed dispersion strengthening as well as some degree of grain refinement over NiAl, while TiB 2 dispersoid-containing material showed grain refinement as well as secondary recrystallization and did not improve high-temperature strength. Hot-pack rolling was also performed to develop thin sheet materials (1.27-mm thick) and from these alloys. Without dispersoids, NiAl rolled easily at 1,223 K and showed low flow stress and good ductility during the hot-rolling operation. Rolling of dispersoid-containing alloys was difficult due to strain localization and edge-cracking effects, resulting partly from the high flow stress at the higher strain rate during the rolling operation. Sheet rolling initially produced a {111} texture, which eventually broke into multiple-texture components with severe deformation

Genome analysis coupled with physiological studies reveals a diverse nitrogen metabolism in Methylocystis sp. strain SC2.

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Bomba Dam

Full Text Available BACKGROUND: Methylocystis sp. strain SC2 can adapt to a wide range of methane concentrations. This is due to the presence of two isozymes of particulate methane monooxygenase exhibiting different methane oxidation kinetics. To gain insight into the underlying genetic information, its genome was sequenced and found to comprise a 3.77 Mb chromosome and two large plasmids. PRINCIPAL FINDINGS: We report important features of the strain SC2 genome. Its sequence is compared with those of seven other methanotroph genomes, comprising members of the Alphaproteobacteria, Gammaproteobacteria, and Verrucomicrobia. While the pan-genome of all eight methanotroph genomes totals 19,358 CDS, only 154 CDS are shared. The number of core genes increased with phylogenetic relatedness: 328 CDS for proteobacterial methanotrophs and 1,853 CDS for the three alphaproteobacterial Methylocystaceae members, Methylocystis sp. strain SC2 and strain Rockwell, and Methylosinus trichosporium OB3b. The comparative study was coupled with physiological experiments to verify that strain SC2 has diverse nitrogen metabolism capabilities. In correspondence to a full complement of 34 genes involved in N2 fixation, strain SC2 was found to grow with atmospheric N2 as the sole nitrogen source, preferably at low oxygen concentrations. Denitrification-mediated accumulation of 0.7 nmol (30N2/hr/mg dry weight of cells under anoxic conditions was detected by tracer analysis. N2 production is related to the activities of plasmid-borne nitric oxide and nitrous oxide reductases. CONCLUSIONS/PERSPECTIVES: Presence of a complete denitrification pathway in strain SC2, including the plasmid-encoded nosRZDFYX operon, is unique among known methanotrophs. However, the exact ecophysiological role of this pathway still needs to be elucidated. Detoxification of toxic nitrogen compounds and energy conservation under oxygen-limiting conditions are among the possible roles. Relevant features that may stimulate

Mycotoxin producing potential of some isolates of Aspergillus flavus and Eurotium groups from meat products.

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el-Kady, I; el-Maraghy, S; Zohri, A N

1994-09-01

All strains (92) of A. flavus group proved to be positive for production of aflatoxin (45 to 1200 micrograms/50 ml medium) on potato dextrose liquid medium, while 59 strains only proved to be positive (35-310 micrograms/50 ml) on 15% NaCl potato-dextrose liquid medium. Most of the strains tested of A. flavus, A. flavus var. columnaris and A. oryzae produced aflatoxins B1, B2, G1 & G2. All positive strains of A. tamarii produced aflatoxins G1 & G2 while the tested isolate of A. zonatus produced aflatoxins B1 & G1. Of 95 strains tested of Eurotium, aflatoxins B1 & G1 were produced by one strain of each of E. chevalieri var. intermedium, E. repens and E. rubrum. Gliotoxin was detected in the extract of two strains of E. chevalieri and one strain of each of E. chevalieri var. intermedium and E. pseudoglaucum on the salt-free medium, and two strains of each of E. chevalieri, E. chevalieri var. intermedium and one of E. pseudoglaucum on 15% NaCl medium. Sterigmatocystin was produced by some strains of E. chevalieri, E. chevalieri var. intermedium, E. amstelodami, E. pseudoglaucum and E. rubrum on the two experimental media. One strain only of E. repens produced ochratoxin A while citrinin was detected in the extract of one strain of E. pseudoglaucum.

Symmetry analysis of strain, electric and magnetic fields in the Bi2Se3-class of topological insulators

DEFF Research Database (Denmark)

Brems, Mathias Rosdahl; Paaske, Jens; Lunde, Anders Mathias

2018-01-01

Based on group theoretical arguments we derive the most general Hamiltonian for the Bi2Se3-class of materials including terms to third order in the wave vector, first order in electric and magnetic fields, first order in strain and first order in both strain and wave vector. We determine analytic......Based on group theoretical arguments we derive the most general Hamiltonian for the Bi2Se3-class of materials including terms to third order in the wave vector, first order in electric and magnetic fields, first order in strain and first order in both strain and wave vector. We determine...... for the effective mass tensor of the Bi2Se3 class of materials as a function of strain and electric field....

Persistence of immunity after vaccination with a capsular group B meningococcal vaccine in 3 different toddler schedules.

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Sadarangani, Manish; Sell, Tim; Iro, Mildred A; Snape, Matthew D; Voysey, Merryn; Finn, Adam; Heath, Paul T; Bona, Gianni; Esposito, Susanna; Diez-Domingo, Javier; Prymula, Roman; Odueyungbo, Adefowope; Toneatto, Daniela; Pollard, Andrew J

2017-10-16

One schedule for the capsular group B meningococcal vaccine 4CMenB is 2 doses that are administered 2 months apart for children aged 12-23 months, with a booster dose 12-24 months later. Our objective was to provide data on persistence of human serum bactericidal antibody (hSBA) titres in children up to 4 years of age after initial doses at 12-24 months, and immunogenicity of a booster dose at 48 months of age compared with vaccine-naive children. Children previously immunized, as part of a randomized controlled trial, with 2 doses of 4CMenB vaccine at 12-24 months of age received a booster at 4 years of age. Vaccine-naive age-matched toddlers received 2 doses of 4CMenB. Human serum bactericidal antibody titres against reference strains H44/76, 5/99, NZ98/254 and M10713 were evaluated before and after innoculation with 4CMenB vaccine in 4-year-old children. Of 332 children in the study, 123 had previously received 4CMenB and 209 were vaccine-naive controls. Before the booster, the proportions of participants (previously vaccinated groups compared with controls) with hSBA titres of 1:5 or more were as follows: 9%-11% v. 1% (H44/76), 84%-100% v. 4% (5/99), 0%-18% v. 0% (NZ98/254) and 59%-60% v. 60% (M10713). After 1 dose of 4CMenB in previously immunized children, the proportions of participants achieving hSBA titres of 1:5 or more were 100% (H44/76 and 5/99), 70%-100% (NZ98/254) and 90%-100% (M10713). We found that waning of hSBA titres by 4 years of age occurred after 2 doses of 4CMenB vaccine administered at 12-24 months, and doses at 12-24 months have a priming effect on the immune system. A booster may be necessary to maintain hSBA titres of 1:5 or more among those children with increased disease risk. Trial registration : ClinicalTrials.gov, no. NCT01717638. © 2017 Canadian Medical Association or its licensors.

Effect of challenge of pigs previously immunised with inactivated vaccines containing homologous and heterologous Mycoplasma hyopneumoniae strains

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Villarreal Iris

2012-01-01

Full Text Available Abstract Background Mycoplasma hyopneumoniae is the primary cause of enzootic pneumonia in pigs. Although vaccination is an important control tool, the results observed under field conditions are variable. This may be due to antigenic differences between the strains circulating in pig herds and the vaccine strain. This study compared the protective efficacy of four bacterins against challenge infection with a highly virulent field strain of M. hyopneumoniae. Seventy eight, one-week old piglets were randomly assigned to five treatment groups (A, B, C, D, E, 14 piglets each, and a negative control group (F consisting of 8 piglets. All pigs were injected at 1 (D7 and 4 weeks of age (D28, with 2 ml of either a placebo or a bacterin based on selected M. hyopneumoniae strains, namely A (F7.2C, B (F20.1L, C (B2V1W20 1A-F, D (J strain, E (placebo; positive control, F (placebo; negative control. At D56, all pigs except those of group F were challenged intratracheally with 7 ml culture medium containing 107 CCU/ml of M. hyopneumoniae strain F7.2C. All pigs were euthanized and necropsied at D84. The severity of coughing and pneumonia lesions were the main parameters. Immunofluorescence (IF testing, nested PCR testing of bronchoalveolar lavage (BAL fluid and serology for M. hyopneumoniae were also performed. Results The different bacterins only slightly improved clinical symptoms (average 0.38 in vaccinated groups vs. 0.45 in group E and histopathological lung lesions (average 3.20 in vaccinated groups vs. 3.45 in group E, but did not improve macroscopic lung lesions (score 4.30 vs. 4.03 in group E. None of the vaccines was significantly and/or consistently better or worse than the other ones. All bacterins evoked a serological response in the vaccinated animals. All pigs, except those from group F, were positive with nPCR in BAL fluid at D84. Conclusion The bacterins did not induce a clear overall protection against challenge infection, and there were no

Effect of challenge of pigs previously immunised with inactivated vaccines containing homologous and heterologous Mycoplasma hyopneumoniae strains.

Science.gov (United States)

Villarreal, Iris; Vranckx, Katleen; Calus, Dries; Pasmans, Frank; Haesebrouck, Freddy; Maes, Dominiek

2012-01-06

Mycoplasma hyopneumoniae is the primary cause of enzootic pneumonia in pigs. Although vaccination is an important control tool, the results observed under field conditions are variable. This may be due to antigenic differences between the strains circulating in pig herds and the vaccine strain. This study compared the protective efficacy of four bacterins against challenge infection with a highly virulent field strain of M. hyopneumoniae. Seventy eight, one-week old piglets were randomly assigned to five treatment groups (A, B, C, D, E), 14 piglets each, and a negative control group (F) consisting of 8 piglets. All pigs were injected at 1 (D7) and 4 weeks of age (D28), with 2 ml of either a placebo or a bacterin based on selected M. hyopneumoniae strains, namely A (F7.2C), B (F20.1L), C (B2V1W20 1A-F), D (J strain), E (placebo; positive control), F (placebo; negative control). At D56, all pigs except those of group F were challenged intratracheally with 7 ml culture medium containing 107 CCU/ml of M. hyopneumoniae strain F7.2C. All pigs were euthanized and necropsied at D84. The severity of coughing and pneumonia lesions were the main parameters. Immunofluorescence (IF) testing, nested PCR testing of bronchoalveolar lavage (BAL) fluid and serology for M. hyopneumoniae were also performed. The different bacterins only slightly improved clinical symptoms (average 0.38 in vaccinated groups vs. 0.45 in group E) and histopathological lung lesions (average 3.20 in vaccinated groups vs. 3.45 in group E), but did not improve macroscopic lung lesions (score 4.30 vs. 4.03 in group E). None of the vaccines was significantly and/or consistently better or worse than the other ones. All bacterins evoked a serological response in the vaccinated animals. All pigs, except those from group F, were positive with nPCR in BAL fluid at D84. The bacterins did not induce a clear overall protection against challenge infection, and there were no significant differences in protective

Emericella astellata, a new producer of aflatoxin B-1, B-2 and sterigmatocystin

DEFF Research Database (Denmark)

Frisvad, Jens Christian; Samson, R.A.; Smedsgaard, Jørn

2004-01-01

To report on aflatoxin B-1 and B-2 production from a species of Emericella. Methods and Results: Aflatoxins and sterigmatocystin were determined by high-pressure liquid chromatography (HPLC) with diode array detection and confirmed by HPLC with mass spectrometry detection. Among 30 known species...... of Emericella only one species produced aflatoxin. Strains originating from the same geographical source material had different patterns of aflatoxin and sterigmatocystin production on different media, indicating that epigenetic factors may be involved in the regulation of aflatoxin production. However, two...

Group B Strep Infection: Prevention in Newborns

Science.gov (United States)

... Prevención en los recién nacidos Preventing Early-Onset Group B Strep Disease The two most important ways ... occurs in babies younger than 1 week old) group B strep disease include: Testing all pregnant women ...

Susceptibility of Meningococcal Strains Responsible for Two Serogroup B Outbreaks on U.S. University Campuses to Serum Bactericidal Activity Elicited by the MenB-4C Vaccine.

Science.gov (United States)

Rossi, Raffaella; Beernink, Peter T; Giuntini, Serena; Granoff, Dan M

2015-12-01

In 2013 and 2014, two U.S. universities had meningococcal serogroup B outbreaks (a total of 14 cases) caused by strains from two different clonal complexes. To control the outbreaks, students were immunized with a serogroup B meningococcal vaccine (Novartis) that was not yet licensed in the United States. The vaccine (referred to as MenB-4C) contains four components capable of eliciting bactericidal activity. Both outbreak strains had high expression levels of two of the vaccine antigens (subfamily B factor H binding protein [FHbp] and neisserial heparin binding antigen [NHba]); the university B outbreak strain also had moderate expression of a third antigen, NadA. We investigated the bactericidal activity of sera from mice immunized with FHbp, NHba, or NadA and sera from MenB-4C-immunized infant macaques and an adult human. The postimmunization bactericidal activity of the macaque or human serum against isolates from university B with FHbp identification (ID) 1 that exactly matched the vaccine FHbp sequence variant was 8- to 21-fold higher than that against isolates from university A with FHbp ID 276 (96% identity to the vaccine antigen). Based on the bactericidal activity of mouse antisera to FHbp, NadA, or NHba and macaque or human postimmunization serum that had been depleted of anti-FHbp antibody, the bactericidal activity against both outbreak strains largely or entirely resulted from antibodies to FHbp. Thus, despite the high level of strain expression of FHbp from a subfamily that matched the vaccine antigen, there can be large differences in anti-FHbp bactericidal activity induced by MenB-4C vaccination. Further, strains with moderate to high NadA and/or NHba expression can be resistant to anti-NadA or anti-NHba bactericidal activity elicited by MenB-4C vaccination. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

DIVA vaccine properties of the live chimeric pestivirus strain CP7_E2gif.

Science.gov (United States)

von Rosen, Tanya; Rangelova, Desislava; Nielsen, Jens; Rasmussen, Thomas Bruun; Uttenthal, Åse

2014-06-04

Live modified vaccines to protect against classical swine fever virus (CSFV), based on chimeric pestiviruses, have been developed to enable serological Differentiation of Infected from Vaccinated Animals (DIVA). In this context, the chimeric virus CP7_E2gif vaccine candidate is unique as it does not include any CSFV components. In the present study, the DIVA vaccine properties of CP7_E2gif were evaluated in comparison to the conventional live attenuated Riemser C-strain vaccine. Sera and tonsil samples obtained from pigs immunised with these two vaccines were analysed. No viral RNA was found in serum after vaccination with CP7_E2gif, whereas some serum samples from C-strain vaccinated animals were positive. In both vaccinated groups, individual viral RNA-positive tonsil samples were detected in animals euthanised between 7 and 21 days post vaccination. Furthermore, serum samples from these animals, together with archival samples from pigs vaccinated with CP7_E2gif and subsequently CSFV challenged, were analysed for specific antibodies using ELISAs and for homologous neutralising antibodies. In animals vaccinated with CP7_E2gif, neutralising antibodies were detected from day 10. However, the sera remained negative for anti-CSFV E2-specific antibodies whereas pigs vaccinated with C-strain seroconverted against CSFV by 14 days after vaccination, as determined by a CSFV-E2 specific blocking ELISA. One week after subsequent CSFV challenge, a strong anti-CSFV E2 reaction was detected in CP7_E2gif vaccinated pigs and anti-E(rns) antibodies were detected from 10 days after infection. In conclusion, CP7_E2gif has the potential to be used as a DIVA vaccine in combination with detection of anti-CSFV E2-specific antibodies. Copyright © 2014 Elsevier B.V. All rights reserved.

Techno-functional differentiation of two vitamin B12 producing Lactobacillus plantarum strains: an elucidation for diverse future use.

Science.gov (United States)

Bhushan, Bharat; Tomar, S K; Chauhan, Arun

2017-01-01

An appropriate selection of Lactobacillus strain (probiotic/starter/functional) on the basis of its techno-functional characteristics is required before developing a novel fermented functional food. We compared vitamin B 12 (B 12 , cobalamin) producing Lactobacillus plantarum isolates, BHM10 and BCF20, for functional (vitamin over-production, genomic insight to B 12 structural genes, and probiotic attributes) and technological [milks (skim and soy) fermentation and B 12 bio-fortification] characteristics. Addition of B 12 precursors (5-amonolevulinate and dimethylbenzimidazole) to cobalamin-free fermentation medium increased vitamin production in BHM10, BCF20, and DSM20016 (a positive standard) by 3.4-, 4.4-, and 3.86-folds, respectively. Three important B 12 structural genes were detected in L. plantarum species (strains BHM10 and BCF20) by PCR for the first time. The gene sequences were submitted to NCBI GenBank and found phylogenetically closer to respective sequences in B 12 producing Lactobacillus reuteri strains. During comparative probiotic testing, BCF20 showed significantly higher (p < 0.05 to p < 0.001) gastrointestinal tolerance and cell surface hydrophobicity (p < 0.05) than BHM10. Moreover, only BCF20 was found positive for BSH activity and also exhibited comparatively better antagonistic potential against potent pathogens. Conversely, high acid and bile susceptible strain BHM10 displayed significantly higher soy milk fermentation and resultant B 12 bio-fortification abilities during technological testing. Two B 12 quantification techniques, UFLC and competitive immunoassay, confirmed the in vitro and in situ bio-production of bio-available form of B 12 after BHM10 fermentation. Conclusively, techno-functional differentiation of two B 12 producing strains elucidates their diverse future use; BCF20 either for B 12 over-production (in vitro) or as a probiotic candidate, while BHM10 for cobalamin bio-fortification (in situ) in soy milk.

26 CFR 301.6223(b)-1 - Notice group.

Science.gov (United States)

2010-04-01

... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Notice group. 301.6223(b)-1 Section 301.6223(b... ADMINISTRATION PROCEDURE AND ADMINISTRATION Assessment In General § 301.6223(b)-1 Notice group. (a) In general. If a group of partners having in the aggregate a 5 percent or more interest in the profits of a...

MgB2 thin films by hybrid physical-chemical vapor deposition

International Nuclear Information System (INIS)

Xi, X.X.; Pogrebnyakov, A.V.; Xu, S.Y.; Chen, K.; Cui, Y.; Maertz, E.C.; Zhuang, C.G.; Li, Qi; Lamborn, D.R.; Redwing, J.M.; Liu, Z.K.; Soukiassian, A.; Schlom, D.G.; Weng, X.J.; Dickey, E.C.; Chen, Y.B.; Tian, W.; Pan, X.Q.; Cybart, S.A.; Dynes, R.C.

2007-01-01

Hybrid physical-chemical vapor deposition (HPCVD) has been the most effective technique for depositing MgB 2 thin films. It generates high magnesium vapor pressures and provides a clean environment for the growth of high purity MgB 2 films. The epitaxial pure MgB 2 films grown by HPCVD show higher-than-bulk T c due to tensile strain in the films. The HPCVD films are the cleanest MgB 2 materials reported, allowing basic research, such as on magnetoresistance, that reveals the two-band nature of MgB 2 . The carbon-alloyed HPCVD films demonstrate record-high H c2 values promising for high magnetic field applications. The HPCVD films and multilayers have enabled the fabrication of high quality MgB 2 Josephson junctions

[Genetic diversity of extraintestinal Escherichia coli strains producers of beta-lactamases TEM, SHV and CTX-M associated with healthcare].

Science.gov (United States)

Varela, Yasmin; Millán, Beatriz; Araque, María

2017-06-01

There are few reports from Venezuela describing the genetic basis that sustains the pathogenic potential and phylogenetics of Escherichia coli extraintestinal strains isolated in health care units. To establish the genetic diversity of extraintestinal E. coli strains producers of betalactamases TEM, SHV and CTX-M associated with healthcare. We studied a collection of 12 strains of extraintestinal E. coli with diminished sensitivity to broad-spectrum cephalosporins. Antimicrobial susceptibility was determined by minimum inhibitory concentration. We determined the phylogenetic groups, virulence factors and genes encoding antimicrobial resistance using PCR, and clonal characterization by repetitive element palindromic-PCR rep-PCR. All strains showed resistance to cephalosporins and joint resistance to quinolones and aminoglycosides. The phylogenetic distribution showed that the A and B1 groups were the most frequent, followed by D and B2. We found all the virulence factors analyzed in the B2 group, and fimH gene was the most frequent among them. We found blaCTX-M in all strains,with a higher prevalence of blaCTX-M-8; two of these strains showed coproduction of blaCTX-M-9 and were genetically identified as blaCTXM-65 and blaCTX-M-147 by sequencing. The strains under study showed genetic diversity, hosting a variety of virulence genes, as well as antimicrobial resistance with no particular phylogroup prevalence. This is the first report of blaCTX-M alleles in Venezuela and in the world associated to non-genetically related strains isolated in health care units, a situation that deserves attention, as well as the rationalization of antimicrobials use.

Role of some selected Bifidobacterium strains in modulating immunosenescence of aged albino rats

Directory of Open Access Journals (Sweden)

Hanan A. El-Bakry

2013-10-01

Full Text Available Probiotic administration has been associated with enhanced immune function in elderly subjects. However, approaches for selection of an “ideal” strain of bifidobacteria are still difficult. The aim of the present study is to investigate the possible modulatory effects of three strains of Bifidobacterium species (Bifidobacterium adolescentis ATCC 15704, Bifidobacterium breve ATCC 15700 and Bifidobacterium longum ATCC 15707 on haematological and immunological parameters of aged albino rats corresponding to normal adult ones. The animals were divided into six groups; three groups of aged rats were fed yoghurt inoculated with one of the Bifidobacterium strains; one group of aged rats was fed yoghurt alone (control aged; two groups of adult and aged rats were provided with normal diet and assigned as normal groups. The total leucocyte count was significantly increased in the three bifidobacteria-treated aged groups as compared with both normal and control aged rats. Serum IgA level was considerably increased in all treated rats. On the contrary, serum IgE level was significantly decreased in rats supplemented with yoghurt inoculated with B. adolescentis or B. breve. Both B. adolescentis and B. breve groups showed significant enhanced production of TNF-α. Furthermore, the production of cytokine IL-8 was significantly increased in the B. adolescentis group. Interestingly, it was apparent that only B. adolescentis had the most pronounced effect on aged rats to regain nearly normal values as measured in normal adult rats. Conclusively, the present work indicates that dietary consumption of selected bifidobacteria strains may have a particular application in the elderly especially in terms of immunomodulation.

(SELAX strain) B2 amplicon

African Journals Online (AJOL)

USER

2010-07-12

Jul 12, 2010 ... enzyme was inactivated by heating at 75°C for 10 min after the addition of 2 µl of ... material of the vector DNA and the partial genomic digests were packaged in ... tubes. The tubes were incubated for 15 min at 37°C. Molten LB ... Plaque transfer was carried out for 2 min with ink markings made on the agar ...

Digital Image Correlation of 2D X-ray Powder Diffraction Data for Lattice Strain Evaluation

Science.gov (United States)

Zhang, Hongjia; Sui, Tan; Daisenberger, Dominik; Fong, Kai Soon

2018-01-01

High energy 2D X-ray powder diffraction experiments are widely used for lattice strain measurement. The 2D to 1D conversion of diffraction patterns is a necessary step used to prepare the data for full pattern refinement, but is inefficient when only peak centre position information is required for lattice strain evaluation. The multi-step conversion process is likely to lead to increased errors associated with the ‘caking’ (radial binning) or fitting procedures. A new method is proposed here that relies on direct Digital Image Correlation analysis of 2D X-ray powder diffraction patterns (XRD-DIC, for short). As an example of using XRD-DIC, residual strain values along the central line in a Mg AZ31B alloy bar after 3-point bending are calculated by using both XRD-DIC and the conventional ‘caking’ with fitting procedures. Comparison of the results for strain values in different azimuthal angles demonstrates excellent agreement between the two methods. The principal strains and directions are calculated using multiple direction strain data, leading to full in-plane strain evaluation. It is therefore concluded that XRD-DIC provides a reliable and robust method for strain evaluation from 2D powder diffraction data. The XRD-DIC approach simplifies the analysis process by skipping 2D to 1D conversion, and opens new possibilities for robust 2D powder diffraction data analysis for full in-plane strain evaluation. PMID:29543728

Digital Image Correlation of 2D X-ray Powder Diffraction Data for Lattice Strain Evaluation

Directory of Open Access Journals (Sweden)

Hongjia Zhang

2018-03-01

Full Text Available High energy 2D X-ray powder diffraction experiments are widely used for lattice strain measurement. The 2D to 1D conversion of diffraction patterns is a necessary step used to prepare the data for full pattern refinement, but is inefficient when only peak centre position information is required for lattice strain evaluation. The multi-step conversion process is likely to lead to increased errors associated with the ‘caking’ (radial binning or fitting procedures. A new method is proposed here that relies on direct Digital Image Correlation analysis of 2D X-ray powder diffraction patterns (XRD-DIC, for short. As an example of using XRD-DIC, residual strain values along the central line in a Mg AZ31B alloy bar after 3-point bending are calculated by using both XRD-DIC and the conventional ‘caking’ with fitting procedures. Comparison of the results for strain values in different azimuthal angles demonstrates excellent agreement between the two methods. The principal strains and directions are calculated using multiple direction strain data, leading to full in-plane strain evaluation. It is therefore concluded that XRD-DIC provides a reliable and robust method for strain evaluation from 2D powder diffraction data. The XRD-DIC approach simplifies the analysis process by skipping 2D to 1D conversion, and opens new possibilities for robust 2D powder diffraction data analysis for full in-plane strain evaluation.

Resurgence of canine parvovirus 2a strain in the domestic dog population from Argentina.

Science.gov (United States)

Calderón, Marina Gallo; Romanutti, Carina; Wilda, Maximiliano; D' Antuono, Alejandra; Keller, Leticia; Giacomodonato, Mónica N; Mattion, Nora; La Torre, José

2015-09-15

Ninety-three rectal swab samples were taken, from dogs suspected of canine parvovirus (CPV) infection and analyzed by PCR. A fragment of the VP2 gene, was amplified in 41 (44%) of them, resulting CPV positive samples. Sequencing analysis of these PCR products showed that 37 samples (90.2%) belonged to the CPV2c type, whereas four samples (9.8%) were identified as CPV2a, which has not been found since 2008. It was also found that 24 out of 37 CPV2c samples (65%), carried the mutation Thr440Ala, whereas this mutation was absent in the four CPV2a strains reported herein. Using phylogenetic analysis of the full length VP2 gene, which was amplified by PCR in six local samples, it was seen that CPV2a Argentine strains reported in this study, were genetically closer to a previous local CPV2a isolate (year 2003) and to a South African CPV2a strain, than to any of the recently reported Uruguayan CPV2a strains. The results obtained in this work, together with those reported previously in Uruguay strongly suggest that, in spite of the geographical proximity, wild type CPV strains undergo different evolutive pathways in each country, resulting in the prevalence of different strains in related dog populations. Further extensive epidemiological studies are needed in order to improve the understanding of CPV evolution. Copyright © 2015 Elsevier B.V. All rights reserved.

Ecological divergence of a novel group of Chloroflexus strains along a geothermal gradient.

Science.gov (United States)

Weltzer, Michael L; Miller, Scott R

2013-02-01

Environmental gradients are expected to promote the diversification and coexistence of ecological specialists adapted to local conditions. Consistent with this view, genera of phototrophic microorganisms in alkaline geothermal systems generally appear to consist of anciently divergent populations which have specialized on different temperature habitats. At White Creek (Lower Geyser Basin, Yellowstone National Park), however, a novel, 16S rRNA-defined lineage of the filamentous anoxygenic phototroph Chloroflexus (OTU 10, phylum Chloroflexi) occupies a much wider thermal niche than other 16S rRNA-defined groups of phototrophic bacteria. This suggests that Chloroflexus OTU 10 is either an ecological generalist or, alternatively, a group of cryptic thermal specialists which have recently diverged. To distinguish between these alternatives, we first isolated laboratory strains of Chloroflexus OTU 10 from along the White Creek temperature gradient. These strains are identical for partial gene sequences encoding the 16S rRNA and malonyl coenzyme A (CoA) reductase. However, strains isolated from upstream and downstream samples could be distinguished based on sequence variation at pcs, which encodes the propionyl-CoA synthase of the 3-hydroxypropionate pathway of carbon fixation used by the genus Chloroflexus. We next demonstrated that strains have diverged in temperature range for growth. Specifically, we obtained evidence for a positive correlation between thermal niche breadth and temperature optimum, with strains isolated from lower temperatures exhibiting greater thermal specialization than the most thermotolerant strain. The study has implications for our understanding of both the process of niche diversification of microorganisms and how diversity is organized in these hot spring communities.

Efficient production of 2,3-butanediol from corn stover hydrolysate by using a thermophilic Bacillus licheniformis strain.

Science.gov (United States)

Li, Lixiang; Li, Kun; Wang, Kai; Chen, Chao; Gao, Chao; Ma, Cuiqing; Xu, Ping

2014-10-01

In this study, a thermophilic Bacillus licheniformis strain X10 was newly isolated for 2,3-butanediol (2,3-BD) production from lignocellulosic hydrolysate. Strain X10 could utilize glucose and xylose simultaneously without carbon catabolite repression. In addition, strain X10 possesses high tolerance to fermentation inhibitors including furfural, vanillin, formic acid, and acetic acid. In a fed-batch fermentation, 74.0g/L of 2,3-BD was obtained from corn stover hydrolysate, with a productivity of 2.1g/Lh and a yield of 94.6%. Thus, this thermophilic B. licheniformis strain is a candidate for the development of efficient industrial production of 2,3-BD from corn stover hydrolysate. Copyright © 2014 Elsevier Ltd. All rights reserved.

Production and testing of HENDL-2.1/CG coarse-group cross-section library based on ENDF/B-VII.0

International Nuclear Information System (INIS)

Xu Dezheng; He Zhaozhong; Zou Jun; Zeng Qin

2010-01-01

A coarse-group coupled neutron and photon (27n + 21γ) cross-section library HENDL-2.1/CG, based on ENDF/B-VII.0 evaluate data source, has been produced by FDS Team in Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP). HENDL-2.1/CG containing 350 nuclide cross-section files (from 1 H to 252 Cf) was generated in MATXS format with the NJOY processing system and then by compiling coarse-group problem-dependent format using the TRANSX code. In order to verify the availability and reliability of the HENDL-2.1/CG data library, requisite benchmark calculations were performed and compared with HENDL-2.0/MG fine-group coupled neutron and photon (175n + 42γ) cross-section library. In general, results using the coarse-group library showed similarly believable as fine-group library.

Multiferroic Properties of o-LuMnO3 Controlled by b-Axis Strain

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Windsor, Y. W.; Huang, S. W.; Hu, Y.; Rettig, L.; Alberca, A.; Shimamoto, K.; Scagnoli, V.; Lippert, T.; Schneider, C. W.; Staub, U.

2014-10-01

Strain is a leading candidate for controlling magnetoelectric coupling in multiferroics. Here, we use x-ray diffraction to study the coupling between magnetic order and structural distortion in epitaxial films of the orthorhombic (o-) perovskite LuMnO3. An antiferromagnetic spin canting in the E-type magnetic structure is shown to be related to the ferroelectrically induced structural distortion and to a change in the magnetic propagation vector. By comparing films of different orientations and thicknesses, these quantities are found to be controlled by b-axis strain. It is shown that compressive strain destabilizes the commensurate E-type structure and reduces its accompanying ferroelectric distortion.

Protect Your Baby from Group B Strep

Centers for Disease Control (CDC) Podcasts

In this podcast, Tarayn Fairlie, a pediatrician and mom, talks about group B strep in pregnant women, the serious effects it can have on newborns, how you can find out if you have group B strep bacteria in your body and what to do to prevent spreading it to your infant.

Topical imiquimod before intradermal trivalent influenza vaccine for protection against heterologous non-vaccine and antigenically drifted viruses: a single-centre, double-blind, randomised, controlled phase 2b/3 trial.

Science.gov (United States)

Hung, Ivan Fan-Ngai; Zhang, Anna Jinxia; To, Kelvin Kai-Wang; Chan, Jasper Fuk-Woo; Li, Patrick; Wong, Tin-Lun; Zhang, Ricky; Chan, Tuen-Ching; Chan, Brian Chun-Yuan; Wai, Harrison Ho; Chan, Lok-Wun; Fong, Hugo Pak-Yiu; Hui, Raymond Kar-Ching; Kong, Ka-Lun; Leung, Arthur Chun-Fung; Ngan, Abe Ho-Ting; Tsang, Louise Wing-Ki; Yeung, Alex Pat-Chung; Yiu, Geo Chi-Ngo; Yung, Wing; Lau, Johnson Y-N; Chen, Honglin; Chan, Kwok-Hung; Yuen, Kwok-Yung

2016-02-01

Pretreatment with topical imiquimod, a synthetic agonist of toll-like receptor 7, significantly improved the immunogenicity of influenza vaccination in elderly people. We aimed to clarify its effect in a younger age group. In this double-blind, randomised controlled trial, we enrolled healthy volunteers aged 18-30 years in early 2014 to receive the 2013-14 northern-hemisphere winter trivalent influenza vaccine at the Queen Mary Hospital, (Hong Kong, China). Eligible participants were randomly assigned (1:1:1:1) to one of the four vaccination groups: the study group, topical imiquimod-cream followed by intradermal trivalent influenza vaccine (INF-Q-ID), or one of three control groups, topical aqueous-cream control followed by intradermal trivalent influenza vaccine (INF-C-ID), topical aqueous-cream control followed by intramuscular trivalent influenza vaccine (INF-C-IM), and topical imiquimod-cream followed by intradermal normal-saline injection (SAL-Q-ID). Randomisation was by computer-generated lists in blocks of four. The type of topical treatment was masked from volunteers and investigators, although not from the study nurse. Serum haemagglutination-inhibition and microneutralisation-antibody titres were assayed. The primary outcome was seroconversion at day 7 after treatment for three vaccine strains of influenza (A/California/07/2009 H1N1-like virus [A/California/H1N1], A/Victoria/361/2011 H3N2-like virus [A/Victoria/H3N2], and B/Massachusetts/2/2012-like virus [B/Yamagata lineage]) and four non-vaccine strains (A/HK/485197/14 [H3N2 Switzerland-like lineage], prototype A/WSN/1933 [H1N1], A/HK/408027/09 [prepandemic seasonal H1N1], and B/HK/418078/11 [Victoria lineage]). Analysis was done on an intention-to-treat basis. This trial is registered with ClinicalTrials.gov, number NCT02103023. We enrolled 160 healthy volunteers between March 1 and May 31, 2014, and 40 participants were randomly assigned to each study group. For the A/California/H1N1 strain

Impacts of diurnal variation of ultraviolet-B and photosynthetically active radiation on phycobiliproteins of the hot-spring cyanobacterium Nostoc sp. strain HKAR-2.

Science.gov (United States)

Kannaujiya, Vinod K; Sinha, Rajeshwar P

2017-01-01

The effects of diurnal variation of photosynthetically active radiation (PAR; 400-700 nm) and ultraviolet-B (UV-B; 280-315 nm) radiation on phycobiliproteins (PBPs) and photosynthetic pigments (PP) have been studied in the hot-spring cyanobacterium Nostoc sp. strain HKAR-2. The variations in PBPs and PP were monitored by alternating light and dark under PAR, UV-B, and PAR + UV-B radiations over a period of 25 h. There was a decline in the amount of Chl a and PBPs during light periods of UV-B and PAR + UV-B and an increase during dark periods showing a circadian rhythm by destruction and resynthesis of pigment-protein complex. However, a marked induction in carotenoids was recorded during light periods of the same radiations. Moreover, the ratio of Chl a/PE and Chl a/PC was increased in dark periods showing the resynthesis of bleached Chl a. The wavelength shift in emission fluorescence of PBPs toward shorter wavelengths further indicated the bleaching and destruction of PBPs during light periods. Oxidative damage upon exposure to PAR, UV-B, and PAR + UV-B was alleviated by induction of antioxidative enzymes such as superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX). The studied cyanobacterium exhibits a significant increase in the activities of SOD, CAT, and APX upon exposure to UV-B and PAR + UV-B radiations. The results indicate that pigment-protein composition of Nostoc sp. stain HKAR-2 was significantly altered during diurnal variation of light/radiation, which might play an important role in optimization for their productivity in a particular cyanobacterium.

Characterization of Lactobacillus salivarius strains B37 and B60 capable of inhibiting IL-8 production in Helicobacter pylori-stimulated gastric epithelial cells.

Science.gov (United States)

Panpetch, Wimonrat; Spinler, Jennifer K; Versalovic, James; Tumwasorn, Somying

2016-10-18

Interleukin (IL)-8 is the key agent for initiating an inflammatory response to infection with Helicobacter pylori. Some strains of Lactobacillus spp. are known to colonize the stomach and suppress inflammation caused by H. pylori. In this study, we characterized two gastric-derived lactobacilli, Lactobacillus salivarius (LS) strains B37 and B60, capable of inhibiting H. pylori-induced IL-8 production by gastric epithelial cells. Conditioned media from LS-B37 and LS-B60 suppressed H. pylori-induced IL-8 production and mRNA expression from AGS cells without inhibiting H. pylori growth. These conditioned media suppressed the activation of NF-κB but did not suppress c-Jun activation. IL-8 inhibitory substances in conditioned media of LS-B37 and LS-B60 are heat-stable and larger than 100 kDa in size. The inhibitory activity of LS-B37 was abolished when the conditioned medium was treated with α-amylase but still remained when treated with either proteinase K, trypsin, lipase or lysozyme. The activity of LS-B60 was abolished when the conditioned medium was treated with either amylase or proteinase K but still remained when treated with lysozyme. Treatment with lipase and trypsin also significantly affected the inhibitory activity of LS-B60 although the conditioned medium retained IL-8 suppression statistically different from media control. These results suggest that L. salivarius strains B37 and B60 produce different immunomodulatory factors capable of suppressing H. pylori-induced IL-8 production from gastric epithelial cells. Our results suggest that the large, heat-stable immunomodulatory substance(s) present in the LCM of LS-B37 is a polysaccharide, while the one(s) of LS-B60 is either complex consisting of components of polysaccharide, lipid and protein or includes multiple components such as glycoprotein and lipoprotein.

Prevalence, PFGE typing, and antibiotic resistance of Bacillus cereus group isolated from food in Morocco.

Science.gov (United States)

Merzougui, Souad; Lkhider, Mustapha; Grosset, Noel; Gautier, Michel; Cohen, Nozha

2014-02-01

This article reports the prevalence and antibiotic resistance of the Bacillus cereus group isolated from different foods (milk and dairy products, spices, and rice salad) in Morocco. In total, 402 different food samples collected from 2008 to 2010 were analyzed by microbiological methods to isolate B. cereus. The strains were subjected to a polymerase chain reaction test in order to verify whether they belonged to the B. cereus group. Sixty-four of all isolates (15.9%) were found to be positive. Among the sources, B. cereus strains from milk and dairy products constituted the largest proportion of isolates (33/64; 51.6%) followed by spices (22/64; 34.4%) and salad with rice (9/64; 14.1%). The genetic diversity of the strains of B. cereus group was examined by pulsed-field gel electrophoresis (PFGE) of chromosomal DNA digested with SmaI. The enzyme restriction profiles showed a high degree of polymorphism among the strains. The results showed that PFGE analysis could reveal the genetic differences among B. cereus strains. Investigation of antibiotic-resistance profiles showed that isolates were resistant to ampicillin (98.4%), tetracycline (90.6%), oxacillin (100%), cefepime (100%), and penicillin (100%), and were susceptible to chloramphenicol (67.2%), erythromycin (84.4%), and gentamicin (100%). The results of this study indicated that B. cereus could be a significant etiological agent of food poisoning in Morocco because of its high prevalence. Also, we demonstrated that the majority of strains came from milk and dairy products. However, additional research involving cytotoxicity tests is needed to more evaluate this sanitary risk.

Relationship between ureB Sequence Diversity, Urease Activity and Genotypic Variations of Different Helicobacter pylori Strains in Patients with Gastric Disorders.

Science.gov (United States)

Ghalehnoei, Hossein; Ahmadzadeh, Alireza; Farzi, Nastaran; Alebouyeh, Masoud; Aghdaei, Hamid Asadzadeh; Azimzadeh, Pendram; Molaei, Mahsa; Zali, Mohammad Reza

2016-01-01

Association of the severity of Helicobacter pylori induced diseases with virulence entity of the colonized strains was proven in some studies. Urease has been demonstrated as a potent virulence factor for H. pylori. The main aim of this study was investigation of the relationships of ureB sequence diversity, urease activity and virulence genotypes of different H. pylori strains with histopathological changes of gastric tissue in infected patients suffering from different gastric disorders. Analysis of the virulence genotypes in the isolated strains indicated significant associations between the presence of severe active gastritis and cagA+ (P = 0.039) or cagA/iceA1 genotypes (P = 0.026), and intestinal metaplasia and vacA m1 (P = 0.008) or vacA s1/m2 (P = 0.001) genotypes. Our results showed a 2.4-fold increased risk of peptic ulcer (95% CI: 0.483-11.93), compared with gastritis, in the infected patients who had dupA positive strains; however this association was not statistically significant. The results of urease activity showed a significant mean difference between the isolated strains from patients with PUD and NUD (P = 0.034). This activity was relatively higher among patients with intestinal metaplasia. Also a significant association was found between the lack of cagA and increased urease activity among the isolated strains (P = 0.036). While the greatest sequence variation of ureB was detected in a strain from a patient with intestinal metaplasia, the sole determined amino acid change in UreB sequence (Ala201Thr, 30%), showed no influence on urease activity. In conclusion, the supposed role of H. pylori urease to form peptic ulcer and advancing of intestinal metaplasia was postulated in this study. Higher urease activity in the colonizing H. pylori strains that present specific virulence factors was indicated as a risk factor for promotion of histopathological changes of gastric tissue that advance gastric malignancy.

[Chloroquine analogues from benzofuro- and benzothieno[3,2-b]-4-pyridone-2-carboxylic acid esters].

Science.gov (United States)

Gölitzer, K; Meyer, H; Jomaa, H; Wiesner, J

2004-08-01

The amides 7 were synthesized from the annulated methyl 4-pyridone-2-carboxylates 4 via the carboxylic acids 5 and their acid chlorides by reacting with the novaldiamine base 6. The alcohol 8b, obtained from DIBAH reduction of the ester 4b, was transformed to the chloromethyl derivative 9 which reacted with 6 and 18-crown-6 leading to the 2-novaldiaminomethyl-4-pyridone 10. Compound 10 was obtained with higher yield from DIBAH reduction of the amide 7b. The substances 7 and 10 were inactive when tested against the chloroquine resistant Plasmodium falciparum strain Dd2.

Spontaneous strain and microstructures of YBa2(Cu1-xCox)3O7-δ

International Nuclear Information System (INIS)

Schmahl, W.W.; Putnis, A.; Salje, E.; Blunt, J.; Zhang, D.N.; Freeman, P.; Graeme-Barber, A.

1991-01-01

Substitution of Co or Fe on the Cu(1) site in YBa 2 Cu 3 O 7-δ is known to decrease the ferroelastic spontaneous strain (orthorhombic) ε=2(b-a)/(a+b) and thus induce a macroscopic ferroelastic-paraelastic phase change from orthorhombic to tetragonal symmetry. Other substituents such as Zn and Ni preferentially occupy the Cu(2) sites, and do not show a pronounced effect on the orthorhombicity. Twinning on {110} occurs as a consequence of the ferroelastic spontaneous strain ε in the orthorhombic phase, and ε also controls the equilibrium spacing between the {110} twin planes. Hence chemical doping provides an excellent tool to control the number of twin planes per unit volume and to study potential flux-pinning properties of the twin microstructure. (orig.)

On the Representation Theory of the Ultrahyperbolic BMS group UHB(2, 2). I. General Results

International Nuclear Information System (INIS)

Melas, Evangelos

2015-01-01

The Bondi-Metzner-Sachs (BMS) group B is the common asymptotic group of all asymptotically flat (lorentzian) space-times, and is the best candidate for the universal symmetry group of General Relativity (G.R.). B admits generalizations to real space-times of any signature, to complex space-times, and supersymmetric generalizations for any space- time dimension. With this motivation McCarthy constructed the strongly continuous unitary irreducible representations (IRs) of B some time ago, and he identified B(2,2) as the generalization of B appropriate to the to the 'ultrahyperbolic signature' (+,+,−,−) and asymptotic flatness in null directions. We continue this programme by introducing a new group UHB(2, 2) in the group theoretical study of ultrahyperbolic G.R. which happens to be a proper subgroup of B(2, 2). In this short paper we report on the first general results on the representation theory of UHB(2, 2). In particular the main general results are that the all little groups of UHB(2, 2) are compact and that the Wigner-Mackey's inducing construction is exhaustive despite the fact that UHB(2, 2) is not locally compact in the employed Hilbert topology. At the end of the paper we comment on the significance of these results

Fumonisin and Ochratoxin Production in Industrial Aspergillus niger Strains

Science.gov (United States)

Frisvad, Jens C.; Larsen, Thomas O.; Thrane, Ulf; Meijer, Martin; Varga, Janos; Samson, Robert A.; Nielsen, Kristian F.

2011-01-01

Aspergillus niger is perhaps the most important fungus used in biotechnology, and is also one of the most commonly encountered fungi contaminating foods and feedstuffs, and occurring in soil and indoor environments. Many of its industrial applications have been given GRAS status (generally regarded as safe). However, A. niger has the potential to produce two groups of potentially carcinogenic mycotoxins: fumonisins and ochratoxins. In this study all available industrial and many non-industrial strains of A. niger (180 strains) as well as 228 strains from 17 related black Aspergillus species were examined for mycotoxin production. None of the related 17 species of black Aspergilli produced fumonisins. Fumonisins (B2, B4, and B6) were detected in 81% of A. niger, and ochratoxin A in 17%, while 10% of the strains produced both mycotoxins. Among the industrial strains the same ratios were 83%, 33% and 26% respectively. Some of the most frequently used strains in industry NRRL 337, 3112 and 3122 produced both toxins and several strains used for citric acid production were among the best producers of fumonisins in pure agar culture. Most strains used for other biotechnological processes also produced fumonisins. Strains optimized through random mutagenesis usually maintained their mycotoxin production capability. Toxigenic strains were also able to produce the toxins on media suggested for citric acid production with most of the toxins found in the biomass, thereby questioning the use of the remaining biomass as animal feed. In conclusion it is recommended to use strains of A. niger with inactive or inactivated gene clusters for fumonisins and ochratoxins, or to choose isolates for biotechnological uses in related non-toxigenic species such as A. tubingensis, A. brasiliensis, A vadensis or A. acidus, which neither produce fumonisins nor ochratoxins. PMID:21853139

Validity test of the IPD-Work consortium approach for creating comparable job strain groups between Job Content Questionnaire and Demand-Control Questionnaire

Directory of Open Access Journals (Sweden)

Bongkyoo Choi

2015-04-01

Full Text Available Objectives: This study aims to test the validity of the IPD-Work Consortium approach for creating comparable job strain groups between the Job Content Questionnaire (JCQ and the Demand-Control Questionnaire (DCQ. Material and Methods: A random population sample (N = 682 of all middle-aged Malmö males and females was given a questionnaire with the 14-item JCQ and 11-item DCQ for the job control and job demands. The JCQ job control and job demands scores were calculated in 3 different ways: using the 14-item JCQ standard scale formulas (method 1; dropping 3 job control items and using the 11-item JCQ standard scale formulas with additional scale weights (method 2; and the approach of the IPD Group (method 3, dropping 3 job control items, but using the simple 11-item summation-based scale formulas. The high job strain was defined as a combination of high demands and low control. Results: Between the 2 questionnaires, false negatives for the high job strain were much greater than false positives (37–49% vs. 7–13%. When the method 3 was applied, the sensitivity of the JCQ for the high job strain against the DCQ was lowest (0.51 vs. 0.60–0.63 when the methods 1 and 2 were applied, although the specificity was highest (0.93 vs. 0.87–0.89 when the methods 1 and 2 were applied. The prevalence of the high job strain with the JCQ (the method 3 was applied was considerably lower (4–7% than with the JCQ (the methods 1 and 2 were applied and the DCQ. The number of congruent cases for the high job strain between the 2 questionnaires was smallest when the method 3 was applied. Conclusions: The IPD-Work Consortium approach showed 2 major weaknesses to be used for epidemiological studies on the high job strain and health outcomes as compared to the standard JCQ methods: the greater misclassification of the high job strain and lower prevalence of the high job strain.

Detection of virulence genes and the phylogenetic groups of Escherichia coli isolated from dogs in Brazil

Directory of Open Access Journals (Sweden)

Fernanda Morcatti Coura

2018-02-01

Full Text Available ABSTRACT: This study identified the virulence genes, pathovars, and phylogenetic groups of Escherichia coli strains obtained from the feces of dogs with and without diarrhea. Virulence genes and phylogenetic group identification were studied using polymerase chain reaction. Thirty-seven E. coli isolates were positive for at least one virulence factor gene. Twenty-one (57.8% of the positive isolates were isolated from diarrheal feces and sixteen (43.2% were from the feces of non-diarrheic dogs. Enteropathogenic E. coli (EPEC were the most frequently (62.2% detected pathovar in dog feces and were mainly from phylogroup B1 and E. Necrotoxigenic E. coli were detected in 16.2% of the virulence-positive isolates and these contained the cytotoxic necrotizing factor 1 (cnf1 gene and were classified into phylogroups B2 and D. All E. coli strains were negative for the presence of enterotoxigenic E. coli (ETEC enterotoxin genes, but four strains were positive for ETEC-related fimbriae 987P and F18. Two isolates were Shiga toxin-producing E. coli strains and contained the toxin genesStx2 or Stx2e, both from phylogroup B1. Our data showed that EPEC was the most frequent pathovar and B1 and E were the most common phylogroups detected in E. coli isolated from the feces of diarrheic and non-diarrheic dogs.

A Bivalent Meningococcal B Vaccine in Adolescents and Young Adults.

Science.gov (United States)

Ostergaard, Lars; Vesikari, Timo; Absalon, Judith; Beeslaar, Johannes; Ward, Brian J; Senders, Shelly; Eiden, Joseph J; Jansen, Kathrin U; Anderson, Annaliesa S; York, Laura J; Jones, Thomas R; Harris, Shannon L; O'Neill, Robert; Radley, David; Maansson, Roger; Prégaldien, Jean-Louis; Ginis, John; Staerke, Nina B; Perez, John L

2017-12-14

MenB-FHbp is a licensed meningococcal B vaccine targeting factor H-binding protein. Two phase 3 studies assessed the safety of the vaccine and its immunogenicity against diverse strains of group B meningococcus. We randomly assigned 3596 adolescents (10 to 18 years of age) to receive MenB-FHbp or hepatitis A virus vaccine and saline and assigned 3304 young adults (18 to 25 years of age) to receive MenB-FHbp or saline at baseline, 2 months, and 6 months. Immunogenicity was assessed in serum bactericidal assays that included human complement (hSBAs). We used 14 meningococcal B test strains that expressed vaccine-heterologous factor H-binding proteins representative of meningococcal B epidemiologic diversity; an hSBA titer of at least 1:4 is the accepted correlate of protection. The five primary end points were the proportion of participants who had an increase in their hSBA titer for each of 4 primary strains by a factor of 4 or more and the proportion of those who had an hSBA titer at least as high as the lower limit of quantitation (1:8 or 1:16) for all 4 strains combined after dose 3. We also assessed the hSBA responses to the primary strains after dose 2; hSBA responses to the 10 additional strains after doses 2 and 3 were assessed in a subgroup of participants only. Safety was assessed in participants who received at least one dose. In the modified intention-to-treat population, the percentage of adolescents who had an increase in the hSBA titer by a factor of 4 or more against each primary strain ranged from 56.0 to 85.3% after dose 2 and from 78.8 to 90.2% after dose 3; the percentages of young adults ranged from 54.6 to 85.6% and 78.9 to 89.7%, after doses 2 and 3, respectively. Composite responses after doses 2 and 3 in adolescents were 53.7% and 82.7%, respectively, and those in young adults were 63.3% and 84.5%, respectively. Responses to the 4 primary strains were predictive of responses to the 10 additional strains. Most of those who received MenB