-
Journal of Medical Microbiology Aug 1989Eight of 22 non-capsulate strains of Neisseria meningitidis previously isolated from primary school children were re-identified as N. polysaccharea by aminopeptidase...
Eight of 22 non-capsulate strains of Neisseria meningitidis previously isolated from primary school children were re-identified as N. polysaccharea by aminopeptidase reactions and polysaccharide production. N. polysaccharea was not identified amongst 91 non-capsulate strains of N. meningitidis isolated from adults attending the Genito-urinary Medicine clinic, Westminster Hospital, London. The biochemical reactions of N. polysaccharea strains were similar to those of N. lactamica and N. gonorrhoeae, but N. polysaccharea could be distinguished from these organisms by examination of beta-galactosidase activity, carbohydrate reactions and polysaccharide production. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis revealed closer similarity of N. polysaccharea to N. lactamica than to the pathogenic Neisseria spp. An additional finding was variation in the position of one of the major proteins of N. lactamica in the 34-39-Kda region.
Topics: Aminopeptidases; Bacterial Proteins; Electrophoresis, Polyacrylamide Gel; Neisseria; Neisseria meningitidis; Phenotype; Species Specificity
PubMed: 2503617
DOI: 10.1099/00222615-29-4-251 -
Antimicrobial Agents and Chemotherapy Nov 1990We studied the susceptibilities of relatively penicillin G-resistant and -susceptible strains of Neisseria meningitidis, as well as Neisseria lactamica and Neisseria...
We studied the susceptibilities of relatively penicillin G-resistant and -susceptible strains of Neisseria meningitidis, as well as Neisseria lactamica and Neisseria polysaccharea, to penicillin, ampicillin, and several cephalosporins. The MICs of penicillin, ampicillin, cephalothin, and cefuroxime for moderately resistant meningococci have increased two- to sixfold in relation to MICs for susceptible strains. For these strains of meningococci, N. lactamica, and N. polysaccharea, penicillin, ampicillin, cephalothin, and cefuroxime MICs for 50 and 90% of strains were similar. By genetic transformation of a penicillin-susceptible strain of N. meningitidis to low-level penicillin resistance with DNA from penicillin-resistant strains of N. meningitidis, N. lactamica, N. polysaccharea, and N. gonorrhoeae, isogenic strains with the same pattern of resistance to beta-lactams were obtained, suggesting that these commensal Neisseria spp. could be the source of meningococcal resistance genes.
Topics: Anti-Bacterial Agents; DNA, Bacterial; Drug Resistance, Microbial; Neisseria; Neisseria meningitidis; Penicillin Resistance; Phenotype; Transformation, Genetic; beta-Lactams
PubMed: 2127349
DOI: 10.1128/AAC.34.11.2269 -
Journal of Clinical Microbiology Jun 2014
Topics: Diagnostic Errors; Humans; Neisseria; Neisseriaceae Infections; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 24696027
DOI: 10.1128/JCM.00664-14 -
Food Chemistry Jun 2020Turanose, a potential novel sweetener in food industry, can be synthesized by Neisseria polysaccharea amylosucrase (NpAS). However, the malt-oligosaccharide byproduct...
Turanose, a potential novel sweetener in food industry, can be synthesized by Neisseria polysaccharea amylosucrase (NpAS). However, the malt-oligosaccharide byproduct affects the yield. In this study, the NpAS mutant G396S, which was expected to interfer with the extension of glucan by increasing steric hindrance, was obtained. The NpAS and G396S were heterologously expressed in Bacillus subtilis and enzyme properties were analyzed. Results showed that the polymerization activity of G396S was decreased. In addition, the mutant was used in the preparation of turanose. When using 2 M sucrose as substrate, the turanose yield reached 410.4 g·L, an increase of 61 g·L compared with that of NpAS. When fructose was added, the optimal fructose concentration for G396S decreased from 0.75 M to 0.5 M. The turanose production reached 523 g·L with the conversion rate of 76.5%. This study contributes the use of turanose in food industry.
Topics: Bacillus subtilis; Bacterial Proteins; Disaccharides; Fructose; Glucans; Glucosyltransferases; Neisseria; Recombinant Proteins; Sucrose; Sweetening Agents
PubMed: 31972410
DOI: 10.1016/j.foodchem.2020.126212 -
Scientific Reports Sep 2019Of the ten human-restricted Neisseria species two, Neisseria meningitidis, and Neisseria gonorrhoeae, cause invasive disease: the other eight are carried...
Of the ten human-restricted Neisseria species two, Neisseria meningitidis, and Neisseria gonorrhoeae, cause invasive disease: the other eight are carried asymptomatically in the pharynx, possibly modulating meningococcal and gonococcal infections. Consequently, characterizing their diversity is important for understanding the microbiome in health and disease. Whole genome sequences from 181 Neisseria isolates were examined, including those of three well-defined species (N. meningitidis; N. gonorrhoeae; and Neisseria polysaccharea) and genomes of isolates unassigned to any species (Nspp). Sequence analysis of ribosomal genes, and a set of core (cgMLST) genes were used to infer phylogenetic relationships. Average Nucleotide Identity (ANI) and phenotypic data were used to define species clusters, and morphological and metabolic differences among them. Phylogenetic analyses identified two polyphyletic clusters (N. polysaccharea and Nspp.), while, cgMLST data grouped Nspp isolates into nine clusters and identified at least three N. polysaccharea clusters. ANI results classified Nspp into seven putative species, and also indicated at least three putative N. polysaccharea species. Electron microscopy identified morphological differences among these species. This genomic approach provided a consistent methodology for species characterization using distinct phylogenetic clusters. Seven putative novel Neisseria species were identified, confirming the importance of genomic studies in the characterization of the genus Neisseria.
Topics: DNA, Bacterial; Genome, Bacterial; Genomics; Humans; Neisseria; Phylogeny; Whole Genome Sequencing
PubMed: 31551478
DOI: 10.1038/s41598-019-50203-2 -
FEBS Letters Apr 2000Amylosucrase is a glucosyltransferase that synthesises an insoluble alpha-glucan from sucrose. The catalytic properties of the highly purified amylosucrase from...
Amylosucrase is a glucosyltransferase that synthesises an insoluble alpha-glucan from sucrose. The catalytic properties of the highly purified amylosucrase from Neisseria polysaccharea were characterised. Contrary to previously published results, it was demonstrated that in the presence of sucrose alone, several reactions are catalysed, in addition to polymer synthesis: sucrose hydrolysis, maltose and maltotriose synthesis by successive transfers of the glucosyl moiety of sucrose onto the released glucose, and finally turanose and trehalulose synthesis - these two sucrose isomers being obtained by glucosyl transfer onto fructose. The effect of initial sucrose concentration on initial activity demonstrated a non-Michaelian profile never previously described.
Topics: Catalysis; Chromatography, High Pressure Liquid; Disaccharides; Dose-Response Relationship, Drug; Fructose; Glucose; Glucosyltransferases; Hydrolysis; Isomerism; Kinetics; Magnetic Resonance Spectroscopy; Maltose; Neisseria; Polymers; Solubility; Sucrose; Trisaccharides
PubMed: 10767427
DOI: 10.1016/s0014-5793(00)01406-x -
International Journal of Biological... Jul 2019Amylosucrase (AS) is a glycosyltransferase that produces linear α-1,4 glucans using sucrose as the sole substrate. In this study, for various applications,...
Amylosucrase (AS) is a glycosyltransferase that produces linear α-1,4 glucans using sucrose as the sole substrate. In this study, for various applications, α-glucan-coated starch (α-GCS) was produced by AS (20 U/L) from Neisseria polysaccharea to improve the physicochemical properties of raw normal corn starch (NCS) by applying different reaction conditions (i.e., varying the substrate concentration, pH, and temperature). Field-emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) showed that raw NCS was successfully coated by α-glucan. Differential scanning calorimetry (DSC) and rapid viscosity analyses (RVA) of the α-GCS confirmed that the α-glucan coating decreased the degree of retrogradation. Notably, compared to raw NCS as a control, starch retrogradation was significantly (p < 0.05) decreased by 13.7% after five weeks. Therefore, the novel α-GCS can be applied as a functional material for controlled retrogradation in the starch-based food industry for shelf-life extension.
Topics: Chemical Phenomena; Food Storage; Glucans; Glucosyltransferases; Neisseria; Solubility; Starch
PubMed: 31004643
DOI: 10.1016/j.ijbiomac.2019.04.133 -
Journal of Clinical Microbiology Sep 2014
Topics: Diagnostic Errors; Humans; Neisseria; Neisseriaceae Infections; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 24966359
DOI: 10.1128/JCM.01703-14 -
Annales de L'Institut Pasteur.... 1986Deoxyribonucleic acid relatedness studies (S1 nuclease method with DE-81 filters method) indicated that Neisseria gonorrhoeae, N. meningitidis, N. lactamica and "N.... (Comparative Study)
Comparative Study
Deoxyribonucleic acid relatedness studies (S1 nuclease method with DE-81 filters method) indicated that Neisseria gonorrhoeae, N. meningitidis, N. lactamica and "N. polysaccharea" form a single genospecies, in which four subspecies can be delineated. However, from a clinical and practical viewpoint, it seems desirable to maintain N. gonorrhoeae, N. meningitidis, N. lactamica and "N. polysaccharea" as separate species. N. cinerea is a valid species, closely related to N. gonorrhoeae, N. meningitidis, N. lactamica and "N. polysaccharea". These five species were O to 46% related to the other known species of the genus Neisseria.
Topics: DNA, Bacterial; Neisseria; Neisseria gonorrhoeae; Neisseria meningitidis; Nucleic Acid Hybridization
PubMed: 3120761
DOI: 10.1016/s0769-2609(86)80106-5 -
Carbohydrate Polymers Oct 2017Amylosucrase from Neisseria polysaccharea naturally catalyzes the synthesis of α-1,4 glucans from sucrose. The product profile is quite polydisperse, ranging from...
Amylosucrase from Neisseria polysaccharea naturally catalyzes the synthesis of α-1,4 glucans from sucrose. The product profile is quite polydisperse, ranging from soluble chains called maltooligosaccharides to high-molecular weight insoluble amylose. This enzyme was recently subjected to engineering of its active site to enable recognition of non-natural acceptor substrates. Libraries of variants were constructed and screened on sucrose, allowing the identification of a mutant that showed a 6-fold enhanced activity toward sucrose compared to the wild-type enzyme. Furthermore, its product profile was unprecedented, as only soluble maltooligosaccharides of controlled size chains (2
Topics: Glucosyltransferases; Neisseria; Oligosaccharides; Protein Engineering; Sucrose
PubMed: 28732882
DOI: 10.1016/j.carbpol.2017.06.011