WorldWideScience

Sample records for streptococcus thermophilus lmg18311

  1. Genome-Scale Model of Streptococcus thermophilus LMG18311 for Metabolic Comparison of Lactic Acid Bacteria

    NARCIS (Netherlands)

    Pastink, M.I.; Teusink, B.; Hols, P.; Visser, S.; Vos, de W.M.; Hugenholtz, J.

    2009-01-01

    In this report we describe amino acid-metabolism and amino acid-dependency of the dairy bacterium Streptococcus thermophilus LMG18311 and compare that with two other characterized lactic acid bacteria, Lactococcus lactis and Lactobacillus plantarum. Through the construction of a genome-scale

  2. Genome-scale model of Streptococcus thermophilus LMG18311 for metabolic comparison.

    NARCIS (Netherlands)

    Pastink, M.I.; Teusink, B.; Hols, P.; Visser, S.; Vos, W.M.; Hugenholtz, J.

    2009-01-01

    In this report, we describe the amino acid metabolism and amino acid dependency of the dairy bacterium Streptococcus thermophilus LMG18311 and compare them with those of two other characterized lactic acid bacteria, Lactococcus lactis and Lactobacillus plantarum. Through the construction of a

  3. The rgg0182 gene encodes a transcriptional regulator required for the full Streptococcus thermophilus LMG18311 thermal adaptation

    Directory of Open Access Journals (Sweden)

    Bertin Stéphane

    2011-10-01

    Full Text Available Abstract Background Streptococcus thermophilus is an important starter strain for the production of yogurt and cheeses. The analysis of sequenced genomes of four strains of S. thermophilus indicates that they contain several genes of the rgg familly potentially encoding transcriptional regulators. Some of the Rgg proteins are known to be involved in bacterial stress adaptation. Results In this study, we demonstrated that Streptococcus thermophilus thermal stress adaptation required the rgg0182 gene which transcription depends on the culture medium and the growth temperature. This gene encoded a protein showing similarity with members of the Rgg family transcriptional regulator. Our data confirmed that Rgg0182 is a transcriptional regulator controlling the expression of its neighboring genes as well as chaperones and proteases encoding genes. Therefore, analysis of a Δrgg0182 mutant revealed that this protein played a role in the heat shock adaptation of Streptococcus thermophilus LMG18311. Conclusions These data showed the importance of the Rgg0182 transcriptional regulator on the survival of S. thermophilus during dairy processes and more specifically during changes in temperature.

  4. cse, a Chimeric and variable gene, encodes an extracellular protein involved in cellular segregation in Streptococcus thermophilus.

    Science.gov (United States)

    Borges, Frédéric; Layec, Séverine; Thibessard, Annabelle; Fernandez, Annabelle; Gintz, Brigitte; Hols, Pascal; Decaris, Bernard; Leblond-Bourget, Nathalie

    2005-04-01

    The isolation of a Streptococcus thermophilus CNRZ368 mutant displaying a long-chain phenotype allowed us to identify the cse gene (for cellular segregation). The N terminus of Cse exhibits high similarity to Streptococcus agalactiae surface immunogenic protein (SIP), while its C terminus exhibits high similarity to S. thermophilus PcsB. In CNRZ368, deletion of the entire cse open reading frame leads to drastic lengthening of cell chains and altered colony morphology. Complementation of the Deltacse mutation with a wild-type allele restored both wild-type phenotypes. The central part of Cse is a repeat-rich region with low sequence complexity. Comparison of cse from CNRZ368 and LMG18311 strains reveals high variability of this repeat-rich region. To assess the impact of this central region variability, the central region of LMG18311 cse was exchanged with that of CNRZ368 cse. This replacement did not affect chain length, showing that divergence of the central part does not modify cell segregation activity of Cse. The structure of the cse locus suggests that the chimeric organization of cse results from insertion of a duplicated sequence deriving from the pcsB 3' end into an ancestral sip gene. Thus, the cse locus illustrates the module-shuffling mechanism of bacterial gene evolution.

  5. in Streptococcus salivarius subsp. Thermophilus

    African Journals Online (AJOL)

    GREGO

    2007-04-16

    Apr 16, 2007 ... Micrococcus luteus cells and thereby preventing their growth on assay plates. Thermostability of these ... Growth media were supplemented with 10 µg/mL ampicillin to select recombinant S. salivarius subsp. thermophilus and L. lactis and 50 µg/ml ampicillin .... Yeast Saccharomyces cerevisiae. Gene 66: ...

  6. BlpC-regulated bacteriocin production in Streptococcus thermophilus.

    Science.gov (United States)

    Renye, John A; Somkuti, George A

    2013-03-01

    Streptococcus thermophilus B59671 produces a bacteriocin with anti-pediococcal activity, but genes required for its production are not characterized. Genome sequencing of S. thermophilus has identified a genetic locus encoding a quorum sensing (QS) system that regulates production of class II bacteriocins. However, in strains possessing this gene cluster, production of bacteriocin like peptides (Blp) was only observed when excess pheromone was provided. PCR analysis revealed this strain possessed blpC, which encodes the 30-mer QS pheromone. To investigate if BlpC regulates bacteriocin production in S. thermophilus B59671, an integrative vector was used to replace blpC with a gene encoding for kanamycin resistance and the resulting mutant did not inhibit the growth of Pediococcus acidilactici. Constitutive expression of blpC from a shuttle vector restored the bacteriocin production, confirming the blp gene cluster is essential for bacteriocin activity in S. thermophilus B59671.

  7. New advances in exopolysaccharides production of Streptococcus thermophilus.

    Science.gov (United States)

    Cui, Yanhua; Jiang, Xu; Hao, Mengyuan; Qu, Xiaojun; Hu, Tong

    2017-08-01

    Streptococcus thermophilus is the most important thermophilic dairy starter, and is widely used in the dairy industry. Streptococcus thermophilus exopolysaccharides received wide attention over recent decades, because they can improve the properties of the dairy product and confer beneficial health effects. The understanding of the regulatory and biosynthetic mechanisms of EPS will improve the EPS biosynthesis, increase the productivity of EPSs, and develop EPSs with desirable properties. The structure of EPSs is the focus of this study. Revealing the structure-function relationship can lead to increase the knowledge base and from there to increased research of EPS. The EPS yield is a key limiting factor in the research and utilization of EPS. In the present review, biosynthetic pathways and genetics of S. thermophilus EPSs were described and reviewed. At the same time, functional properties and applications of EPS, and strategies for enhancement of EPS production are discussed.

  8. Genomic analysis of dairy starter culture Streptococcus thermophilus MTCC 5461.

    Science.gov (United States)

    Prajapati, Jashbhai B; Nathani, Neelam M; Patel, Amrutlal K; Senan, Suja; Joshi, Chaitanya G

    2013-04-01

    The lactic acid bacterium Streptococcus thermophilus is widely used as a starter culture for the production of dairy products. Whole-genome sequencing is expected to utilize the genetic basis behind the metabolic functioning of lactic acid bacterium (LAB), for development of their use in biotechnological and probiotic applications. We sequenced the whole genome of Streptococcus thermophilus MTCC 5461, the strain isolated from a curd source, by 454 GS-FLX titanium and Ion Torrent PGM. We performed comparative genome analysis using the local BLAST and RDP for 16S rDNA comparison and by the RAST server for functional comparison against the published genome sequence of Streptococcus thermophilus CNRZ 1066. The whole genome size of S. thermophilus MTCC 5461 is of 1.73Mb size with a GC content of 39.3%. Streptococcal virulence-related genes are either inactivated or absent in the strain. The genome possesses coding sequences for features important for a probiotic organism such as adhesion, acid tolerance, bacteriocin production, and lactose utilization, which was found to be conserved among the strains MTCC 5461 and CNRZ 1066. Biochemical analysis revealed the utilization of 17 sugars by the bacterium, where the presence of genes encoding enzymes involved in metabolism for 16 of these 17 sugars were confirmed in the genome. This study supports the facts that the strain MTCC 5461 is nonpathogenic and harbors essential features that can be exploited for its probiotic potential.

  9. Production of [beta]-galactosidase from streptococcus thermophilus for galactooligosaccharides synthesis

    National Research Council Canada - National Science Library

    Vikas Sangwan; Sudhir K Tomar; Babar Ali; Ram R B Singh; Ashish K Singh

    2015-01-01

      Efficiency of different methods for disruption of Streptococcus thermophilus cells, isolated from different dairy products, to release -galactosidase and synthesis of GOS by extracted enzyme using...

  10. New Insights into Various Production Characteristics of Streptococcus thermophilus Strains.

    Science.gov (United States)

    Cui, Yanhua; Xu, Tingting; Qu, Xiaojun; Hu, Tong; Jiang, Xu; Zhao, Chunyu

    2016-10-12

    Streptococcus thermophilus is one of the most valuable homo-fermentative lactic acid bacteria, which, for a long time, has been widely used as a starter for the production of fermented dairy products. The key production characteristics of S. thermophilus, for example the production of extracellular polysaccharide, proteolytic enzymes and flavor substances as well as acidifying capacity etc., have an important effect on the quality of dairy products. The acidification capacity of the strains determines the manufacturing time and quality of dairy products. It depends on the sugar utilization ability of strains. The production of extracellular polysaccharide is beneficial for improving the texture of dairy products. Flavor substances increase the acceptability of dairy products. The proteolytic activity of the strain influences not only the absorption of the nitrogen source, but also the formation of flavor substances. Different strains have obvious differences in production characteristics via long-time evolution and adaptation to environment. Gaining new strains with novel and desirable characteristics is an important long-term goal for researchers and the fermenting industry. The understanding of the potential molecular mechanisms behind important characteristics of different strains will promote the screening and breeding of excellent strains. In this paper, key technological and functional properties of different S. thermophilus strains are discussed, including sugar metabolism, proteolytic system and amino acid metabolism, and polysaccharide and flavor substance biosynthesis. At the same time, diversity of genomes and plasmids of S. thermophilus are presented. Advances in research on key production characteristics and molecular levels of S. thermophilus will increase understanding of molecular mechanisms of different strains with different important characteristics, and improve the industrialization control level for fermented foods.

  11. ORF Alignment: NC_006449 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_006449 gi|55822668 >1jfxA 8 186 70 248 4e-22 ... ref|YP_141109.1| endolysin, putat...ive [Streptococcus thermophilus CNRZ1066] ... ref|YP_139208.1| endolysin, putative [Streptococcus ... ... ... thermophilus LMG 18311] gb|AAV62294.1| endolysin, ... putative [Streptococcus thermophilus CN...RZ1066] ... gb|AAV60393.1| endolysin, putative [Streptococcus ... t

  12. ORF Alignment: NC_006448 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available NC_006448 gi|55820766 >1jfxA 8 186 70 248 4e-22 ... ref|YP_141109.1| endolysin, putat...ive [Streptococcus thermophilus CNRZ1066] ... ref|YP_139208.1| endolysin, putative [Streptococcus ... ... ... thermophilus LMG 18311] gb|AAV62294.1| endolysin, ... putative [Streptococcus thermophilus CN...RZ1066] ... gb|AAV60393.1| endolysin, putative [Streptococcus ... t

  13. Bacteriocin production by Streptococcus thermophilus in complex growth media.

    Science.gov (United States)

    Renye, J A; Somkuti, G A; Garabal, J I; Steinberg, D H

    2016-11-01

    To test if the production of bacteriocins by Streptococcus thermophilus is influenced when grown in various complex media commonly used for the culturing of lactic acid bacteria. Forty-one strains of S. thermophilus were screened for the production of bacteriocins in tryptone/yeast extract/lactose (TYL), M17-lactose (M17L), M17-glucose (M17G) and MRS media. Two strains, ST144 and ST145, were identified as novel bacteriocin producers, with constitutive production observed only in M17G. Strains ST110, ST114 and ST134 constitutively produced bacteriocins in all growth media but ST114 required growth in MRS for its antimicrobial activity to persist in a 24 h culture. The addition of a synthetic quorum sensing peptide (BlpC) induced bacteriocin production by ST106 in all media tested; and by ST118 in TYL and M17L. Strain ST109, which constitutively produced a bacteriocin in TYL and M17 broths, required BlpC induction when grown in MRS. Real-time PCR analysis showed that the natural expression of blpC in ST109 was lower when grown in MRS, suggesting that something in medium interfered with the blp quorum sensing system. As the choice of growth medium influences both bacteriocin production and peptide stability, several types of production media should be tested when screening for novel bacteriocin-producing strains of S. thermophilus.

  14. Characterization of Exopolysaccharide Produced by Streptococcus thermophilus CC30

    Directory of Open Access Journals (Sweden)

    Sri Lakshmi Ramya Krishna Kanamarlapudi

    2017-01-01

    Full Text Available An exopolysaccharide (EPS producing strain CC30 was isolated from raw milk and identified as Streptococcus thermophilus with morphological and 16S sequencing analysis. The strain was shown to produce 1.95 g/L of EPS when grown in skim milk lactose medium at 30°C by increasing the viscosity of the medium. The EPS was isolated and purified, and it was shown to consist of glucose and galactose in 1 : 1 ratio, with molecular weights ranging from 58 to 180 kDa. FTIR spectroscopy indicated the EPS to have amide, hydroxyl, and carboxyl groups. Under Atomic Force Microscopy, EPS showed spike-like lumps of EPS. Scanning Electron Microscopy (SEM studies showed that it had irregular lumps with a coarse surface. The EPS displayed pseudoplastic nature. Thermogravimetric analysis (TGA reported a degradation temperature of 110.84°C. The purified EPS exhibited reducing activity, hydrogen peroxide radical scavenging activity, and emulsification activity. The results of the present study indicated that EPS producing Streptococcus thermophilus could serve as a promising candidate for further exploitation in food industry.

  15. Characterization of Exopolysaccharide Produced by Streptococcus thermophilus CC30

    Science.gov (United States)

    Kanamarlapudi, Sri Lakshmi Ramya Krishna

    2017-01-01

    An exopolysaccharide (EPS) producing strain CC30 was isolated from raw milk and identified as Streptococcus thermophilus with morphological and 16S sequencing analysis. The strain was shown to produce 1.95 g/L of EPS when grown in skim milk lactose medium at 30°C by increasing the viscosity of the medium. The EPS was isolated and purified, and it was shown to consist of glucose and galactose in 1 : 1 ratio, with molecular weights ranging from 58 to 180 kDa. FTIR spectroscopy indicated the EPS to have amide, hydroxyl, and carboxyl groups. Under Atomic Force Microscopy, EPS showed spike-like lumps of EPS. Scanning Electron Microscopy (SEM) studies showed that it had irregular lumps with a coarse surface. The EPS displayed pseudoplastic nature. Thermogravimetric analysis (TGA) reported a degradation temperature of 110.84°C. The purified EPS exhibited reducing activity, hydrogen peroxide radical scavenging activity, and emulsification activity. The results of the present study indicated that EPS producing Streptococcus thermophilus could serve as a promising candidate for further exploitation in food industry. PMID:28815181

  16. BlpC regulated bacteriocin production in Streptococcus thermophilus NRRL-B59671

    Science.gov (United States)

    Streptococcus thermophilus NRRL-B59671 was previously shown to produce a bacteriocin with anti-pediococcal activity, but the genetic components required for production were not characterized. Genome sequencing of several strains of S. thermophilus has identified a genetic locus which encodes a quor...

  17. Genome comparison and physiological characterization of eight Streptococcus thermophilus strains isolated from Italian dairy products

    DEFF Research Database (Denmark)

    Vendramin, Veronica; Treu, Laura; Campanaro, Stefano

    2017-01-01

    Eight Streptococcus thermophilus strains of dairy origin isolated in Italy were chosen to investigate autochthonous bacterial diversity in this important technological species. In the present study a comparative analysis of all the 17 S. thermophilus genomes publicly available was performed to id...

  18. Cold Shock Proteins and Low-Temperature Response of Streptococcus thermophilus CNRZ302

    NARCIS (Netherlands)

    Wouters, Jeroen A.; Rombouts, Frank M.; Vos, Willem M. de; Kuipers, Oscar P.; Abee, Tjakko

    1999-01-01

    Low-temperature adaptation and cryoprotection were studied in the thermophilic lactic acid bacterium Streptococcus thermophilus CNRZ302. S. thermophilus actively adapts to freezing during a pretreatment at 20°C, resulting in an approximately 1,000-fold increased survival after four freeze-thaw

  19. Isolation and partial characterization of a biosurfactant produced by Streptococcus thermophilus A

    NARCIS (Netherlands)

    Rodrigues, Ligia R.; Teixeira, Jose A.; van der Mei, Henny C.; Oliveira, Rosario

    2006-01-01

    Isolation and characterization of the surface active components from the crude biosurfactant produced by Streptococcus thermophilus A was studied. A fraction rich in glycolipids was obtained by the fractionation of crude biosurfactant using hydrophobic interaction chromatography. Molecular (by

  20. Thermophilin 110: a bacteriocin of Streptococcus thermophilus ST110.

    Science.gov (United States)

    Gilbreth, Stefanie E; Somkuti, George A

    2005-09-01

    A screen of thermophilic lactic acid bacteria identified Streptococcus thermophilus strain ST110 as the putative producer of a bacteriocin with high level of activity against pediococci. Thermophilin 110 was isolated from culture supernatant after 16 h of growth and partially purified by a chloroform extraction procedure. The bacteriocin inhibited the growth of several lactic acid bacteria and in the case of Pediococcus acidilactici, it induced cell lysis with the concomitant release of OD260-absorbing material and intracellular enzymes. SDS-PAGE analysis revealed two components with estimated sizes between 4.0 kDa and 4.5 kDa, respectively, with possible involvement in bacteriocin activity as indicated by agar overlay assays with P. acidilactici as the target organism. Thermophilin 110 was inactivated by several proteolytic enzymes and also by alpha-amylase, which indicated the putative requirement of a glycosidic component for activity. The bacteriocin produced by S. thermophilus may be especially useful in the food processing industries to control spoilage caused by pediococci.

  1. Cracking Streptococcus thermophilus to stimulate the growth of the probiotic Lactobacillus casei in co-culture.

    Science.gov (United States)

    Ma, Chengjie; Ma, Aimin; Gong, Guangyu; Liu, Zhenmin; Wu, Zhengjun; Guo, Benheng; Chen, Zhengjun

    2015-10-01

    Lactobacillus casei, a probiotic, and Streptococcus thermophilus, a fast acidifying lactic acid bacterial strain, are both used in the food industry. The aim of this study was to investigate the interaction between L. casei and S. thermophilus in the presence or absence of S. thermophilus-specific bacteriophage during milk fermentation. The acidification capability of L. casei co-cultured with S. thermophilus was significantly higher than that observed for L. casei or S. thermophilus cultured alone. However, the probiotic content (i.e., L. casei cell viability) was low. The fastest acidification and the highest viable L. casei cell count were observed in co-cultures of L. casei and S. thermophilus with S. thermophilus phage. In these co-cultures, S. thermophilus compensated for the slow acid production of L. casei in the early exponential growth phase. Thereafter, phage-induced lysis of the S. thermophilus cells eliminated the competition for nutrients, allowing L. casei to grow well. Additionally, the ruptured S. thermophilus cells released intracellular factors, which further promoted the growth and function of the probiotic bacteria. Crude cellular extract isolated from S. thermophilus also significantly accelerated the growth and propagation of L. casei, supporting the stimulatory role of the phage on this micro-ecosystem. Copyright © 2015. Published by Elsevier B.V.

  2. Efficient Isolation and Functional Analysis of Spontaneous Streptococcus thermophilus Bacteriophage-Insensitive Mutants

    OpenAIRE

    Chengjie Ma; Jinzhong Lin; Guangyu Gong; Zhenmin Liu; Zhengjun Chen; Aimin Ma

    2016-01-01

    The use of bacteriophage-resistant strains that have satisfactory technological properties is essential for preventing phage infections in industrial fermentation processes. Here, we describe an improved method for the isolation of spontaneous Streptococcus thermophilus bacteriophage-insensitive mutants (BIMs). The concentration of large volumes of S. thermophilus secondary cultures, their subculture in skim milk with high titers of bacteriophages, and their inoculation with the fast milk aci...

  3. Streptococcus thermophilus and its biosurfactants inhibit adhesion by Candida spp. on silicone rubber

    NARCIS (Netherlands)

    Busscher, HJ; vanHoogmoed, CG; GeertsemaDoornbusch, GI; vanderKuijlBooij, M; vanderMei, HC

    1997-01-01

    The adhesion of yeasts, two Candida albicans and two Candida tropicalis strains isolated from naturally colonized voice prostheses, to silicone rubber with and without a salivary conditioning film in the absence and presence of adhering Streptococcus thermophilus B, a biosurfactant-releasing dairy

  4. Genome Sequences of Four Italian Streptococcus thermophilus Strains of Dairy Origin

    DEFF Research Database (Denmark)

    Treu, Laura; Vendramin, Veronica; Bovo, Barbara

    2014-01-01

    This report describes the genome sequences of four Streptococcus thermophilus strains, namely, TH982, TH985, TH1477, and 1F8CT, isolated from different dairy environments from the Campania and the Veneto regions in Italy. These data are aimed at increasing the genomic information available on thi...... on this species, which is of paramount importance for the dairy industry....

  5. Inhibition of microbial adhesion to silicone rubber treated with biosurfactant from Streptococcus thermophilus A

    NARCIS (Netherlands)

    Rodrigues, L; van der Mei, H; Banat, IM; Teixeira, J; Oliveira, R

    Microbial adhesion of four bacterial and two yeast strains isolated from explanted voice prostheses to silicone rubber before and after conditioning with a biosurfactant obtained from the probiotic bacterium Streptococcus thermophilus A was investigated in a parallel plate flow chamber. The silicone

  6. Sugar utilisation and conservation of the gal-lac gene cluster in Streptococcus thermophilus

    NARCIS (Netherlands)

    Bogaard, van den P.T.C.; Hols, P.; Kuipers, O.P.; Kleerebezem, M.; Vos, de W.M.

    2004-01-01

    The adaptation to utilise lactose as primary carbon and energy source is a characteristic for Streptococcus thermophilus. These organisms, however only utilise the glucose moiety of lactose while the galactose moiety is excreted into the growth medium. In this study we evaluated the diversity of

  7. Directed Genomic Integration, Gene Replacement, and Integrative Gene Expression in Streptococcus thermophilus

    NARCIS (Netherlands)

    Mollet, Beat; Poolman, Bert; Marciset, Olivier; Delley, Michèle

    Several pGEM5- and pUC19-derived plasmids containing a selectable erythromycin resistance marker were integrated into the chromosome of Streptococcus thermophilus at the loci of the lactose-metabolizing genes. Integration occurred via homologous recombination and resulted in cointegrates between

  8. The thioredoxin system in the dental caries pathogen Streptococcus mutans and the food-industry bacterium Streptococcus thermophilus.

    Science.gov (United States)

    Marco, Salvatore; Rullo, Rosario; Albino, Antonella; Masullo, Mariorosario; De Vendittis, Emmanuele; Amato, Massimo

    2013-11-01

    The Streptococcus genus includes the pathogenic species Streptococcus mutans, the main responsible of dental caries, and the safe microorganism Streptococcus thermophilus, used for the manufacture of dairy products. These facultative anaerobes control the levels of reactive oxygen species (ROS) and indeed, both S. mutans and S. thermophilus possess a cambialistic superoxide dismutase, the key enzyme for a preventive action against ROS. To evaluate the properties of a crucial mechanism for repairing ROS damages, the molecular and functional characterization of the thioredoxin system in these streptococci was investigated. The putative genes encoding its protein components in S. mutans and S. thermophilus were analysed and the corresponding recombinant proteins were purified. A single thioredoxin reductase was obtained from either S. mutans (SmTrxB) or S. thermophilus (StTrxB1), whereas two thioredoxins were prepared from either S. mutans (SmTrxA and SmTrxH1) or S. thermophilus (StTrxA1 and StTrxA2). Both SmTrxB and StTrxB1 reduced the synthetic substrate DTNB in the presence of NADPH, whereas only SmTrxA and StTrxA1 accelerated the insulin reduction in the presence of DTT. To reconstitute an in vitro streptococcal thioredoxin system, the combined activity of the thioredoxin components was tested through the insulin precipitation in the absence of DTT. The assay functions with a combination of SmTrxB or StTrxB1 with either SmTrxA or StTrxA1. These results suggest that the streptococcal members of the thioredoxin system display a direct functional interaction between them and that these protein components are interchangeable within the Streptococcus genus. In conclusion, our data prove the existence of a functioning thioredoxin system even in these microaerophiles. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  9. Short communication: Genomic and phenotypic analyses of exopolysaccharides produced by Streptococcus thermophilus KLDS SM.

    Science.gov (United States)

    Li, Bailiang; Ding, Xiuyun; Evivie, Smith Etareri; Jin, Da; Meng, Yueyue; Huo, Guicheng; Liu, Fei

    2017-10-18

    Streptococcus thermophilus plays important roles in the dairy industry. Streptococcus thermophilus KLDS SM could produce a high amount of exopolysaccharides (EPS). To understand the possible link between the genotype and the phenotype regarding EPS, the complete genome of S. thermophilus KLDS SM was sequenced and investigated in silico for genes related to carbohydrate fermentation, nucleotide sugars synthesis, and EPS gene cluster. We found that S. thermophilus KLDS SM is able to ferment sucrose, mannose, glucose, galactose, and lactose from the genomic research, which was confirmed by API 50 CH (bioMérieux, Marcy l'Etoile, France). The genetic analysis of nucleotide sugars and EPS cluster revealed that the EPS produced by this strain are composed of galactose and glucose, in accordance with the biochemical result. Furthermore, differences in the molecular mass of EPS from S. thermophilus KLDS SM cultivated under different carbon sources were correlated with the transcription levels of the genes encoding chain length determination protein and glycosyltransferase. Our findings provide a better understanding of the link between the genetic elements and the chemical conformation of EPS and a theoretical basis for producing tailor-made EPS through genetic and metabolic engineering approaches. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  10. Carbohydrate Utilization in Streptococcus thermophilus : Characterization of the Genes for Aldose 1-Epimerase (Mutarotase) and UDPglucose 4-Epimerase

    NARCIS (Netherlands)

    Poolman, Bert; Royer, Theresa J.; Mainzer, Stanley E.; Schmidt, Brian F.

    1990-01-01

    The complete nucleotide sequences of the genes encoding aldose 1-epimerase (mutarotase) (galM) and UDPglucose 4-epimerase (galE) and flanking regions of Streptococcus thermophilus have been determined. Both genes are located immediately upstream of the S. thermophilus lac operon. To facilitate the

  11. Mixed-culture transcriptome analysis reveals the molecular basis of mixed-culture growth in Streptococcus thermophilus and Lactobacillus bulgaricus

    NARCIS (Netherlands)

    Sieuwerts, S.; Molenaar, D.; Hijum, van S.A.F.T.; Beerthuyzen, M.; Stevens, M.J.A.; Janssen, P.W.; Ingham, C.J.; Bok, de F.A.M.; Vos, de W.M.; Hylckama Vlieg, van J.E.T.

    2010-01-01

    Many food fermentations are performed using mixed cultures of lactic acid bacteria. Interactions between strains are of key importance for the performance of these fermentations. Yogurt fermentation by Streptococcus thermophilus and Lactobacillus bulgaricus (basonym, Lactobacillus delbrueckii subsp.

  12. Global Survey and Genome Exploration of Bacteriophages Infecting the Lactic Acid Bacterium Streptococcus thermophilus

    Directory of Open Access Journals (Sweden)

    Brian McDonnell

    2017-09-01

    Full Text Available Despite the persistent and costly problem caused by (bacteriophage predation of Streptococcus thermophilus in dairy plants, DNA sequence information relating to these phages remains limited. Genome sequencing is necessary to better understand the diversity and proliferative strategies of virulent phages. In this report, whole genome sequences of 40 distinct bacteriophages infecting S. thermophilus were analyzed for general characteristics, genomic structure and novel features. The bacteriophage genomes display a high degree of conservation within defined groupings, particularly across the structural modules. Supporting this observation, four novel members of a recently discovered third group of S. thermophilus phages (termed the 5093 group were found to be conserved relative to both phage 5093 and to each other. Replication modules of S. thermophilus phages generally fall within two main groups, while such phage genomes typically encode one putative transcriptional regulator. Such features are indicative of widespread functional synteny across genetically distinct phage groups. Phage genomes also display nucleotide divergence between groups, and between individual phages of the same group (within replication modules and at the 3′ end of the lysis module—through various insertions and/or deletions. A previously described multiplex PCR phage detection system was updated to reflect current knowledge on S. thermophilus phages. Furthermore, the structural protein complement as well as the antireceptor (responsible for the initial attachment of the phage to the host cell of a representative of the 5093 group was defined. Our data more than triples the currently available genomic information on S. thermophilus phages, being of significant value to the dairy industry, where genetic knowledge of lytic phages is crucial for phage detection and monitoring purposes. In particular, the updated PCR detection methodology for S. thermophilus phages is

  13. Short communication: technological and genotypic comparison between Streptococcus macedonicus and Streptococcus thermophilus strains coming from the same dairy environment.

    Science.gov (United States)

    Blaiotta, G; Sorrentino, A; Ottombrino, A; Aponte, M

    2011-12-01

    The species Streptococcus thermophilus is widely used for the preparation of several dairy products, and its technological contribution is clear. On the other hand, although Streptococcus macedonicus was first described more than 10 yr ago and, despite the scientific interest around this issue, the exact role of Strep. macedonicus in cheese making has yet to be clarified. In this study, 121 strains belonging to both species and isolated from the same dairy environment were genetically characterized by random amplification of polymorphic DNA (RAPD)-PCR and compared for the main biochemical features of technological interest, such as acid production, galactose utilization, citrate metabolism, exopolysaccharide production, and lipolytic, ureolytic, exocellular proteolytic, and decarboxylasic activities. Analysis by RAPD-PCR highlighted a remarkable genotypic heterogeneity among strains in both species, and, at a similarity level of 78%, all the isolates and reference strains of Strep. thermophilus grouped together and were well separated from the strains of Strep. macedonicus, confirming that these 2 species are different microbial entities. Comparison between genetic and phenotypic or biotechnological data did not reveal any relationships. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  14. Diversity of Streptococcus thermophilus in bacteriocin production; inhibitory spectrum and occurrence of thermophilin genes.

    Science.gov (United States)

    Rossi, Franca; Marzotto, Marta; Cremonese, Silvia; Rizzotti, Lucia; Torriani, Sandra

    2013-08-01

    The bacteriocin-producing Streptococcus thermophilus strains that can dominate in natural dairy ecosystems, may also enhance safety in products obtained from natural cultures. In this study, we sought to identify bacteriocin production and bacteriocin genes in 75 strains of dairy and plant origin. The strains were tested for antimicrobial activity against pathogens or pathogen models, spoiling bacteria, and lactic acid bacteria associated with dairy products. All strains moderately inhibited Staphylococcus aureus P310, none inhibited Listeria innocua LMG 11387(T) or Clostridium tyrobutyricum LMG 1285(T). In addition, 14 were active against one or more indicators in addition to S. aureus P310. Inhibition of other starter bacteria was more common than the inhibition of unwanted microorganisms. The involvement of a proteinaceous compound was ascertained in all cases. Results suggested that the selection of bacteriocinogenic S. thermophilus strains for use in biopreservation must take into account the effects exerted on other lactic acid bacteria. PCR detection of thermophilin genes proved unreliable in predicting antimicrobial activity. For S. thermophilus PRI36 and PRI45, with relevant inhibitory features, the identity of the bacteriocin genes present in the thermophilin 9 cluster was defined, thus revealing novel variants for this genome region. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Genetically engineered immunomodulatory Streptococcus thermophilus strains producing antioxidant enzymes exhibit enhanced anti-inflammatory activities.

    Science.gov (United States)

    Del Carmen, Silvina; de Moreno de LeBlanc, Alejandra; Martin, Rebeca; Chain, Florian; Langella, Philippe; Bermúdez-Humarán, Luis G; LeBlanc, Jean Guy

    2014-02-01

    The aims of this study were to develop strains of lactic acid bacteria (LAB) having both immunomodulatory and antioxidant properties and to evaluate their anti-inflammatory effects both in vitro, in different cellular models, and in vivo, in a mouse model of colitis. Different Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus strains were cocultured with primary cultures of mononuclear cells. Analysis of the pro- and anti-inflammatory cytokines secreted by these cells after coincubation with candidate bacteria revealed that L. delbrueckii subsp. bulgaricus CRL 864 and S. thermophilus CRL 807 display the highest anti-inflammatory profiles in vitro. Moreover, these results were confirmed in vivo by the determination of the cytokine profiles in large intestine samples of mice fed with these strains. S. thermophilus CRL 807 was then transformed with two different plasmids harboring the genes encoding catalase (CAT) or superoxide dismutase (SOD) antioxidant enzymes, and the anti-inflammatory effects of recombinant streptococci were evaluated in a mouse model of colitis induced by trinitrobenzenesulfonic acid (TNBS). Our results showed a decrease in weight loss, lower liver microbial translocation, lower macroscopic and microscopic damage scores, and modulation of the cytokine production in the large intestines of mice treated with either CAT- or SOD-producing streptococci compared to those in mice treated with the wild-type strain or control mice without any treatment. Furthermore, the greatest anti-inflammatory activity was observed in mice receiving a mixture of both CAT- and SOD-producing streptococci. The addition of L. delbrueckii subsp. bulgaricus CRL 864 to this mixture did not improve their beneficial effects. These findings show that genetically engineering a candidate bacterium (e.g., S. thermophilus CRL 807) with intrinsic immunomodulatory properties by introducing a gene expressing an antioxidant enzyme enhances its anti

  16. Streptococcus thermophilus Biofilm Formation: A Remnant Trait of Ancestral Commensal Life?

    Directory of Open Access Journals (Sweden)

    Benoit Couvigny

    Full Text Available Microorganisms have a long history of use in food production and preservation. Their adaptation to food environments has profoundly modified their features, mainly through genomic flux. Streptococcus thermophilus, one of the most frequent starter culture organisms consumed daily by humans emerged recently from a commensal ancestor. As such, it is a useful model for genomic studies of bacterial domestication processes. Many streptococcal species form biofilms, a key feature of the major lifestyle of these bacteria in nature. However, few descriptions of S. thermophilus biofilms have been reported. An analysis of the ability of a representative collection of natural isolates to form biofilms revealed that S. thermophilus was a poor biofilm producer and that this characteristic was associated with an inability to attach firmly to surfaces. The identification of three biofilm-associated genes in the strain producing the most biofilms shed light on the reasons for the rarity of this trait in this species. These genes encode proteins involved in crucial stages of biofilm formation and are heterogeneously distributed between strains. One of the biofilm genes appears to have been acquired by horizontal transfer. The other two are located in loci presenting features of reductive evolution, and are absent from most of the strains analyzed. Their orthologs in commensal bacteria are involved in adhesion to host cells, suggesting that they are remnants of ancestral functions. The biofilm phenotype appears to be a commensal trait that has been lost during the genetic domestication of S. thermophilus, consistent with its adaptation to the milk environment and the selection of starter strains for dairy fermentations.

  17. Production of lactic acid from whey using Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus

    Directory of Open Access Journals (Sweden)

    Adriana M. Rojas

    2015-09-01

    Full Text Available The main objective of this research was to determine the proper growth conditions of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus for the production of lactic acid using serum as substract. This serum was obtain from the department of Cesar, Colombia. Lactic acid is the result of the extraction and purification of fermentation broths in which bacteria Lactobacillus delbrueckii subsp bulgaricus and Streptococcus thermophilus are used, which are usually used for the production of yogurt. The substrate was supplemented with yeast extract, ammonium phosphate as a nitrogen source, and calcium carbonate as a neutralizer, in order to optimize the consumption, by the bacteria, of the main carbohydrate present in serum (lactose. During the fermentation (up to 72 h the inoculums concentration, and temperature were controlled. Purification consisted in esterification, filtration of solids formed during the reaction, and removing of water by evaporation and nitrogen influx. Finally, lactic acid was obtained with 78,0% purity (36.7 g/L, which was characterized by infrared spectroscopy

  18. Conjugative transfer of the integrative conjugative elements ICESt1 and ICESt3 from Streptococcus thermophilus.

    Science.gov (United States)

    Bellanger, Xavier; Roberts, Adam P; Morel, Catherine; Choulet, Frédéric; Pavlovic, Guillaume; Mullany, Peter; Decaris, Bernard; Guédon, Gérard

    2009-04-01

    Integrative and conjugative elements (ICEs), also called conjugative transposons, are genomic islands that excise, self-transfer by conjugation, and integrate in the genome of the recipient bacterium. The current investigation shows the intraspecies conjugative transfer of the first described ICEs in Streptococcus thermophilus, ICESt1 and ICESt3. Mitomycin C, a DNA-damaging agent, derepresses ICESt3 conjugative transfer almost 25-fold. The ICESt3 host range was determined using various members of the Firmicutes as recipients. Whereas numerous ICESt3 transconjugants of Streptococcus pyogenes and Enterococcus faecalis were recovered, only one transconjugant of Lactococcus lactis was obtained. The newly incoming ICEs, except the one from L. lactis, are site-specifically integrated into the 3' end of the fda gene and are still able to excise in these transconjugants. Furthermore, ICESt3 was retransferred from E. faecalis to S. thermophilus. Recombinant plasmids carrying different parts of the ICESt1 recombination module were used to show that the integrase gene is required for the site-specific integration and excision of the ICEs, whereas the excisionase gene is required for the site-specific excision only.

  19. Development of the recombinase-based in vivo expression technology in Streptococcus thermophilus and validation using the lactose operon promoter

    NARCIS (Netherlands)

    Junjua, M.; Galia, W.; Gaci, N.; Uriot, O.; Genay, M.; Bachmann, H.; Kleerebezem, M.; Dary, A.; Roussel, Y.

    2014-01-01


    Aims

    To construct and validate the recombinase-based in vivo expression technology (R-IVET) tool in Streptococcus thermophilus (ST).

    Methods and Results

    The R-IVET system we constructed in the LMD-9 strain includes the plasmid pULNcreB allowing transcriptional fusion

  20. Development of the recombinase-based in vivo expression technology in Streptococcus thermophilus and validation using the lactose operon promoter

    NARCIS (Netherlands)

    Junjua, M.; Galia, W.; Gaci, N.; Uriot, O.; Genay, M.; Bachmann, H.; Kleerebezem, M.; Dary, A.; Roussel, Y.

    2014-01-01

    AIMS: To construct and validate the recombinase-based in vivo expression technology (R-IVET) tool in Streptococcus thermophilus (ST). METHODS AND RESULTS: The R-IVET system we constructed in the LMD-9 strain includes the plasmid pULNcreB allowing transcriptional fusion with the gene of the

  1. In silico prediction of horizontal gene transfer events in Lactobacillus bulgaricus and Streptococcus thermophilus reveals protocooperation in yogurt manufacturing.

    NARCIS (Netherlands)

    Liu, M.; Siezen, R.J.; Nauta, A.

    2009-01-01

    Lactobacillus bulgaricus and Streptococcus thermophilus, used in yogurt starter cultures, are well known for their stability and protocooperation during their coexistence in milk. In this study, we show that a close interaction between the two species also takes place at the genetic level. We

  2. Optimization of a cryoprotective medium to increase the viability of freeze-dried Streptococcus thermophilus by response surface methodology

    Science.gov (United States)

    Streptococcus thermophilus normally exhibits different survival rates in different bacteria medium during freeze-drying. In this study, response surface methodology (RSM) was applied on the design of experiments for optimizing the cryoprotective medium. Results showed that the most significant facto...

  3. Genome Sequences of Streptococcus thermophilus Strains MTH17CL396 and M17PTZA496 from Fontina, an Italian PDO Cheese.

    Science.gov (United States)

    Treu, Laura; Vendramin, Veronica; Bovo, Barbara; Campanaro, Stefano; Corich, Viviana; Giacomini, Alessio

    2014-02-13

    Here is presented the whole-genome sequences of Streptococcus thermophilus strains MTH17CL396 and M17PTZA496, isolated from fontina protected designation of origin (PDO) cheese in the Valle d'Aosta Region (Italy). S. thermophilus is a lactic acid bacterium widely present in dairy products, and these are the first publicly available genome sequences of S. thermophilus strains isolated from cheese.

  4. Genome Sequences of Streptococcus thermophilus Strains MTH17CL396 and M17PTZA496 from Fontina, an Italian PDO Cheese

    DEFF Research Database (Denmark)

    Treu, Laura; Vendramin, Veronica; Bovo, Barbara

    2014-01-01

    Here is presented the whole-genome sequences of Streptococcus thermophilus strains MTH17CL396 and M17PTZA496, isolated from fontina protected designation of origin (PDO) cheese in the Valle d'Aosta Region (Italy). S. thermophilus is a lactic acid bacterium widely present in dairy products......, and these are the first publicly available genome sequences of S. thermophilus strains isolated from cheese....

  5. Therapeutic effect of Streptococcus thermophilus CRL 1190-fermented milk on chronic gastritis

    Science.gov (United States)

    Rodríguez, Cecilia; Medici, Marta; Mozzi, Fernanda; de Valdez, Graciela Font

    2010-01-01

    AIM: To investigate the potential therapeutic effect of exopolysaccharide (EPS)-producing Streptococcus thermophilus (S. thermophilus) CRL 1190 fermented milk on chronic gastritis in Balb/c mice. METHODS: Balb/c mice were fed with the fermented milk for 7 d after inducing gastritis with acetyl-salicylic acid (ASA, 400 mg/kg body weight per day for 10 d). Omeprazole was included in this study as a positive therapeutic control. The gastric inflammatory activity was evaluated from gastric histology and inflammation score, number of interleukin-10 (IL-10), interferon-γ (INFγ) and tumor necrosis factor-α (TNF-α) cytokine-producing cells in the gastric mucosa, and thickness of the mucus layer. RESULTS: Animals receiving treatment with the EPS-producing S. thermophilus CRL 1190 fermented milk showed a conserved gastric mucosa structure similar to that of healthy animals. Inflammation scores of the fermented milk-treated mice were lower than those of mice in the gastritis group (0.2 ± 0.03 vs 2.0 ± 0.6, P < 0.05). A marked decrease in INFγ+ (15 ± 1.0 vs 28 ± 1.2, P < 0.05) and TNF-α+ (16 ± 3.0 vs 33 ± 3.0, P < 0.05) cells and an increase in IL-10+ (28 ± 1.5 vs 14 ± 1.3, P < 0.05) cells compared to the gastritis group, was observed. Also, an increase in the thickness of the mucus gel layer (2.2 ± 0.6 vs 1.0 ± 0.3; 5.1 ± 0.8 vs 1.5 ± 0.4 in the corpus and antrum mucosa, respectively, P < 0.05) compared with the gastritis group was noted. A milk suspension of the purified EPS from S. thermophilus CRL1190 was also effective as therapy for gastritis. CONCLUSION: This study suggests that fermented milk with S. thermophilus CRL 1190 and/or its EPS could be used in novel functional foods as an alternative natural therapy for chronic gastritis induced by ASA. PMID:20355240

  6. Influence of different proteolytic strains of Streptococcus thermophilus in co-culture with Lactobacillus delbrueckii subsp. bulgaricus on the metabolite profile of set-yoghurt

    NARCIS (Netherlands)

    Settachaimongkon, S.; Nout, M.J.R.; Antunes Fernandes, E.C.; Hettinga, K.A.; Vervoort, J.J.M.; Hooijdonk, van A.C.M.; Zwietering, M.H.; Smid, E.J.; Valenberg, van H.J.F.

    2014-01-01

    Proto-cooperation between Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus is one of the key factors that determine the fermentation process and final quality of yoghurt. In this study, the interaction between different proteolytic strains of S. thermophilus and L.

  7. Multiplex Fast Real-Time PCR for Quantitative Detection and Identification of cos- and pac-Type Streptococcus thermophilus Bacteriophages▿ †

    OpenAIRE

    del Rio, Beatriz; Martín, María Cruz; Martínez, Noelia; Alfonso H. Magadán; Alvarez, Miguel A.

    2008-01-01

    The fermentation of milk by Streptococcus thermophilus is a widespread industrial process that is susceptible to bacteriophage attack. In this work, a preventive fast real-time PCR method for the detection, quantification, and identification of types of S. thermophilus phages in 30 min is described.

  8. Draft Genome Sequence of Streptococcus thermophilus C106, a Dairy Isolate from an Artisanal Cheese Produced in the Countryside of Ireland.

    Science.gov (United States)

    Wels, Michiel; Serrano, L Mariela; Eibrink, Beerd-Jan; Backus, Lennart; Bongers, Roger S; Vriesendorp, Bastienne; Siezen, Roland J; van Hijum, Sacha A F T; Meijer, Wilco C

    2015-11-25

    The lactic acid bacterium Streptococcus thermophilus is widely used for the fermentation of dairy products. Here, we present the draft genome sequence of S. thermophilus C106 isolated from an artisanal cheese produced in the countryside of Ireland. Copyright © 2015 Wels et al.

  9. UDP-N-Acetylglucosamine 4-Epimerase Activity Indicates the Presence of N-Acetylgalactosamine in Exopolysaccharides of Streptococcus thermophilus Strains

    Science.gov (United States)

    Degeest, Bart; Vaningelgem, Frederik; Laws, Andrew P.; De Vuyst, Luc

    2001-01-01

    The monomer composition of the exopolysaccharides (EPS) produced by Streptococcus thermophilus LY03 and S. thermophilus Sfi20 were evaluated by high-pressure liquid chromatography with amperometric detection and nuclear magnetic resonance spectroscopy. Both strains produced the same EPS composed of galactose, glucose, and N-acetylgalactosamine. Further, it was demonstrated that the activity of the precursor-producing enzyme UDP-N-acetylglucosamine 4-epimerase, converting UDP-N-acetylglucosamine into UDP-N-acetylgalactosamine, is responsible for the presence of N-acetylgalactosamine in the EPS repeating units of both strains. The activity of UDP-N-acetylglucosamine 4-epimerase was higher in both S. thermophilus strains than in a non-EPS-producing control strain. However, the level of this activity was not correlated with EPS yields, a result independent of the carbohydrate source applied in the fermentation process. On the other hand, both the amounts of EPS and the carbohydrate consumption rates were influenced by the type of carbohydrate source used during S. thermophilus Sfi20 fermentations. A correlation between activities of the enzymes α-phosphoglucomutase, UDP-glucose pyrophosphorylase, and UDP-galactose 4-epimerase and EPS yields was seen. These experiments confirm earlier observed results for S. thermophilus LY03, although S. thermophilus Sfi20 preferentially consumed glucose for EPS production instead of lactose in contrast to the former strain. PMID:11525994

  10. Hydrolysis of milk-derived bioactive peptides by cell-associated extracellular peptidases of Streptococcus thermophilus.

    Science.gov (United States)

    Hafeez, Zeeshan; Cakir-Kiefer, Céline; Girardet, Jean-Michel; Jardin, Julien; Perrin, Clarisse; Dary, Annie; Miclo, Laurent

    2013-11-01

    The trend to confer new functional properties to fermented dairy products by supplementation with bioactive peptides is growing in order to encounter the challenge of health-promoting foods. But these functional ingredients have not to be hydrolysed by proteases of bacteria used in the manufacture of these products. One of the two yoghurt bacteria, Streptococcus thermophilus, has long been considered as weakly proteolytic since its only cell wall-associated subtilisin-like protease, called PrtS, is not always present. Nevertheless, a recent study pointed out a possible peptidase activity in certain strains. In this present study, the stability of milk-derived bioactive peptides, e.g. the anxiolytic peptide, αs1-CN-(f91-97), in the presence of two different S. thermophilus strains with PrtS+ or PrtS− phenotype was studied. Both strains appeared to be capable of hydrolysing the αs1-CN-(f91-97) and other bioactive peptides by recurrent removal of N-terminal residues. The hydrolysis was neither due to intracellular peptidases nor to HtrA protease. Results obtained showed that the observed activity originates from the presence at the surface of both strains of an extracellular aminopeptidase activity. Moreover, a cell wall-associated X-prolyl dipeptidyl peptidase activity was also highlighted when β-casomorphin-7 was used as substrate. All of these findings suggest that, in order to use fermented milks as vector of bioactive peptides, the stability of these bioactive peptides in this kind of products implies to carefully characterize the potential action of the surface proteolytic enzymes of S. thermophilus.

  11. Identification of a genetic determinant responsible for host specificity in Streptococcus thermophilus bacteriophages.

    Science.gov (United States)

    Duplessis, M; Moineau, S

    2001-07-01

    Phage-host interactions remain poorly understood in lactic acid bacteria and essentially in all Gram-positive bacteria. The aim of this study was to identify the phage genetic determinant (anti-receptor) involved in the recognition of Streptococcus thermophilus hosts. The complete genomic sequence of the lytic S. thermophilus phage DT1 was determined previously, and bioinformatic analysis indicated that orf18 might be the anti-receptor gene. The orf18 of six additional S. thermophilus phages was determined (DT2, DT4, MD1, MD2, MD4 and Q5) and compared with the orf18 of DT1. The deduced ORF18 was divided into three domains. The first domain, which contains the N-terminal part of the protein, was conserved in all seven phages. The second domain was detected in only two phages and flanked by a motif called collagen-like repeats. The second domain also contained a variable region (VR1). All seven phages had a third domain that consisted of the C-terminal section of the protein as well as another variable region (VR2). Chimeric DT1 phages were constructed by recombination; a portion of its orf18 was replaced by the corresponding section in orf18 of the phage MD4. All DT1 chimeric phages acquired the host range of phage MD4. Analysis of the orf18 in the chimeric phages revealed that host specificity in phages DT1 and MD4 resulted from VR2. This is the first report on the identification and characterization of a phage gene involved in the host recognition process of Gram-positive bacteria.

  12. Carbohydrate metabolism is essential for the colonization of Streptococcus thermophilus in the digestive tract of gnotobiotic rats.

    Directory of Open Access Journals (Sweden)

    Muriel Thomas

    Full Text Available Streptococcus thermophilus is the archetype of lactose-adapted bacterium and so far, its sugar metabolism has been mainly investigated in vitro. The objective of this work was to study the impact of lactose and lactose permease on S. thermophilus physiology in the gastrointestinal tract (GIT of gnotobiotic rats. We used rats mono-associated with LMD-9 strain and receiving 4.5% lactose. This model allowed the analysis of colonization curves of LMD-9, its metabolic profile, its production of lactate and its interaction with the colon epithelium. Lactose induced a rapid and high level of S. thermophilus in the GIT, where its activity led to 49 mM of intra-luminal L-lactate that was related to the induction of mono-carboxylic transporter mRNAs (SLC16A1 and SLC5A8 and p27(Kip1 cell cycle arrest protein in epithelial cells. In the presence of a continuous lactose supply, S. thermophilus recruited proteins involved in glycolysis and induced the metabolism of alternative sugars as sucrose, galactose, and glycogen. Moreover, inactivation of the lactose transporter, LacS, delayed S. thermophilus colonization. Our results show i/that lactose constitutes a limiting factor for colonization of S. thermophilus, ii/that activation of enzymes involved in carbohydrate metabolism constitutes the metabolic signature of S. thermophilus in the GIT, iii/that the production of lactate settles the dialogue with colon epithelium. We propose a metabolic model of management of carbohydrate resources by S. thermophilus in the GIT. Our results are in accord with the rationale that nutritional allegation via consumption of yogurt alleviates the symptoms of lactose intolerance.

  13. Assembling the Streptococcus thermophilus clustered regularly interspaced short palindromic repeats (CRISPR) array for multiplex DNA targeting.

    Science.gov (United States)

    Guo, Lijun; Xu, Kun; Liu, Zhiyuan; Zhang, Cunfang; Xin, Ying; Zhang, Zhiying

    2015-06-01

    In addition to the advantages of scalable, affordable, and easy to engineer, the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) technology is superior for multiplex targeting, which is laborious and inconvenient when achieved by cloning multiple gRNA expressing cassettes. Here, we report a simple CRISPR array assembling method which will facilitate multiplex targeting usage. First, the Streptococcus thermophilus CRISPR3/Cas locus was cloned. Second, different CRISPR arrays were assembled with different crRNA spacers. Transformation assays using different Escherichia coli strains demonstrated efficient plasmid DNA targeting, and we achieved targeting efficiency up to 95% with an assembled CRISPR array with three crRNA spacers. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Pediocin production in milk by Pediococcus acidilactici in co-culture with Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus.

    Science.gov (United States)

    Somkuti, George A; Steinberg, Dennis H

    2010-01-01

    The production of pediocin in milk by Pediococcus acidilactici was evaluated in co-culture with the dairy fermentation cultures Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus. The cultures were tested singly and in different combinations in milk (0 or 2% fat content) during incubation at 40 degrees C for up to 10 h. Cell-free milk samples taken every 60 min were tested for bacteriocin activity against Listeria monocytogenes. Pediocin activity was not detectable when P. acidilactici was inoculated into milk as a monoculture. When P. acidilactici was grown in combination with the yogurt starter cultures S. thermophilus and Lb. delbrueckii ssp. bulgaricus, pediocin concentration reached 3,200-6,400 units ml(-1) after 8 h of incubation. The results showed that pediocin producing pediococci may be useful adjunct components in mixed cultures of S. thermophilus and Lb. delbrueckii ssp. bulgaricus to amplify the bioprotective properties of fermented dairy foods against Listeria contamination.

  15. Novel Variants of Streptococcus thermophilus Bacteriophages Are Indicative of Genetic Recombination among Phages from Different Bacterial Species

    DEFF Research Database (Denmark)

    Szymczak, Paula; Janzen, Thomas; Neves, Ana Rute

    2017-01-01

    Bacteriophages are the main cause of fermentation failures in dairy plants. The majority of Streptococcus thermophilus phages can be divided into either cos- or pac-type phages and are additionally characterized by examining the V2 region of their antireceptors. We screened a large number of S....... thermophilus phages from the Chr. Hansen A/S collection, using PCR specific for the cos- or pac-type phages, as well as for the V2 antireceptor region. Three phages did not produce positive results with the assays. Analysis of phage morphologies indicated that two of these phages, CHPC577 and CHPC926, had...... shorter tails than the traditional S. thermophilus phages. The third phage, CHPC1151, had a tail size similar to those of the cos- or pac-type phages, but it displayed a different baseplate structure. Sequencing analysis revealed the genetic similarity of CHPC577 and CHPC926 with a subgroup of Lactococcus...

  16. Study of Streptococcus thermophilus population on a world-wide and historical collection by a new MLST scheme.

    Science.gov (United States)

    Delorme, Christine; Legravet, Nicolas; Jamet, Emmanuel; Hoarau, Caroline; Alexandre, Bolotin; El-Sharoud, Walid M; Darwish, Mohamed S; Renault, Pierre

    2017-02-02

    We analyzed 178 Streptococcus thermophilus strains isolated from diverse products, from around the world, over a 60-year period with a new multilocus sequence typing (MLST) scheme. This collection included isolates from two traditional cheese-making sites with different starter-use practices, in sampling campaigns carried out over a three years period. The nucleotide diversity of the S. thermophilus population was limited, but 116 sequence types (ST) were identified. Phylogenetic analysis of the concatenated sequences of the six housekeeping genes revealed the existence of groups confirmed by eBURST analysis. Deeper analyses performed on 25 strains by CRISPR and whole-genome analysis showed that phylogenies obtained by MLST and whole-genome analysis were in agreement but differed from that inferred by CRISPR analysis. Strains isolated from traditional products could cluster in specific groups indicating their origin, but also be mixed in groups containing industrial starter strains. In the traditional cheese-making sites, we found that S. thermophilus persisted on dairy equipment, but that occasionally added starter strains may become dominant. It underlined the impact of starter use that may reshape S. thermophilus populations including in traditional products. This new MLST scheme thus provides a framework for analyses of S. thermophilus populations and the management of its biodiversity. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Streptococcus thermophilus CRISPR-Cas9 Systems Enable Specific Editing of the Human Genome.

    Science.gov (United States)

    Müller, Maximilian; Lee, Ciaran M; Gasiunas, Giedrius; Davis, Timothy H; Cradick, Thomas J; Siksnys, Virginijus; Bao, Gang; Cathomen, Toni; Mussolino, Claudio

    2016-03-01

    RNA-guided nucleases (RGNs) based on the type II CRISPR-Cas9 system of Streptococcus pyogenes (Sp) have been widely used for genome editing in experimental models. However, the nontrivial level of off-target activity reported in several human cells may hamper clinical translation. RGN specificity depends on both the guide RNA (gRNA) and the protospacer adjacent motif (PAM) recognized by the Cas9 protein. We hypothesized that more stringent PAM requirements reduce the occurrence of off-target mutagenesis. To test this postulation, we generated RGNs based on two Streptococcus thermophilus (St) Cas9 proteins, which recognize longer PAMs, and performed a side-by-side comparison of the three RGN systems targeted to matching sites in two endogenous human loci, PRKDC and CARD11. Our results demonstrate that in samples with comparable on-target cleavage activities, significantly lower off-target mutagenesis was detected using St-based RGNs as compared to the standard Sp-RGNs. Moreover, similarly to SpCas9, the StCas9 proteins accepted truncated gRNAs, suggesting that the specificities of St-based RGNs can be further improved. In conclusion, our results show that Cas9 proteins with longer or more restrictive PAM requirements provide a safe alternative to SpCas9-based RGNs and hence a valuable option for future human gene therapy applications.

  18. Properties of Streptococcus thermophilus fermented milk containing variable concentrations of Bifidobacterium longum and Lactobacillus acidophilus Propriedades de leites fermentados por Streptococcus thermophilus contendo concentrações variáveis de Bifidobacterium longum e Lactobacillus acidophilus

    Directory of Open Access Journals (Sweden)

    Patrícia Blumer Zacarchenco

    2006-09-01

    Full Text Available Sensory evaluation and analysis of pH, titratable acidity and microbial counts after 1, 7, 14 and 21 days of storage of five combinations of lyophilized Bifidobacterium longum and/or Lactobacillus acidophilus added to milk fermented with Streptococcus thermophilus were studied during storage at 4ºC. The taste and acidity sensory attributes were significantly (PForam estudadas as características sensoriais, de pH e acidez de cinco combinações de leites fermentados por Streptococcus thermophilus, adicionados de Bifidobacterium longum e/ou Lactobacillus acidophilus liofilizados. Os efeitos sobre as características sensoriais tornaram-se significantes (p < 0,05 com o aumento do tempo de estocagem. As combinações favoritas continham, inicialmente, Bif. longum e L. acidophilus (10(8 e 10(7ufc/mL, respectivamente e Bif. longum apenas (10(8ufc/mL. Estas combinações não diferiram significativamente do leite fermentado padrão, nem entre si. As notas mais baixas e os maiores valores de acidez titulável foram apresentados pelo leite fermentado por Streptococcus thermophilus contendo apenas L. acidophilus (10(8ufc/mL, concentração inicial. Durante 21 dias de estocagem a 4ºC, as contagens de células viáveis de Str. thermophilus não mudaram, as de Bif. longum mantiveram-se constantes ou reduziram em um ciclo logarítmico e, as de L. acidophilus reduziram de 1 a 2 ciclos logarítmicos. Não foi observada inibição da pós-acidificação resultante da presença de bifidobactéria ou L. acidophilus.

  19. Characterization of the chemical structures and physical properties of exopolysaccharides produced by various Streptococcus thermophilus strains.

    Science.gov (United States)

    Pachekrepapol, U; Lucey, J A; Gong, Y; Naran, R; Azadi, P

    2017-05-01

    Exopolysaccharides (EPS) produced by some lactic acid bacteria are often used by the dairy industry to improve the rheological and physical properties of yogurt, but the relationship between their structure and functional effect is still unclear. The EPS from different species, or different strains from the same species, may differ in terms of molar mass, repeating unit structure, and EPS yield during fermentation of milk. This study aimed to characterize the detailed properties of EPS produced from 7 strains of Streptococcus thermophilus, which is one of the key cultures used for yogurt manufacture. Milk was fermented with strains DGCC 7698, DGCC 7710, DGCC 7785, ST-10255y, St-143, STCth-9204, and ST4239. These strains were selected because they have been used in previous studies on yogurt texture, but a complete description of their EPS structural properties has not yet been reported. All strains were fermented under a similar acidification rate by adjusting the level of supplementation with peptone or the inoculation level, which allowed for a comparison of EPS yields under similar growth conditions (reconstituted skim milk at 40°C). The EPS from each strain was isolated and the weight-average molar mass and z-average root mean square radius determined using size-exclusion chromatography multiangle laser light scattering. The monosaccharide composition of EPS was determined using gas chromatography-mass spectrometry, and repeating unit structure was determined using nuclear magnetic resonance spectroscopy. The weight-average molar mass values of EPS ranged from 0.14 to 1.61 × 10(6) g/mol. All 7 EPS samples were uncharged. The strains ST-10255y and ST4239 had EPS with the same repeating unit structure. The monosaccharide compositions of the various EPS were mainly composed of glucose and galactose, with low levels of rhamnose in the EPS isolated from DGCC 7698, and N-acetylgalactosamine in the EPS from DGCC 7785, ST-10255y, and ST4239. The yields of EPS

  20. Highly efficient heritable plant genome engineering using Cas9 orthologues from Streptococcus thermophilus and Staphylococcus aureus.

    Science.gov (United States)

    Steinert, Jeannette; Schiml, Simon; Fauser, Friedrich; Puchta, Holger

    2015-12-01

    The application of the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas system of Streptococcus pyogenes (SpCas9) is currently revolutionizing genome engineering in plants. However, synthetic plant biology will require more complex manipulations of genomes and transcriptomes. The simultaneous addressing of different specific genomic sites with independent enzyme activities within the same cell is a key to this issue. Such approaches can be achieved by the adaptation of additional bacterial orthologues of the CRISPR/Cas system for use in plant cells. Here, we show that codon-optimised Cas9 orthologues from Streptococcus thermophilus (St1Cas9) and Staphylococcus aureus (SaCas9) can both be used to induce error-prone non-homologous end-joining-mediated targeted mutagenesis in the model plant Arabidopsis thaliana at frequencies at least comparable to those that have previously been reported for the S. pyogenes CRISPR/Cas system. Stable inheritance of the induced targeted mutations of the ADH1 gene was demonstrated for both St1Cas9- and SaCas9-based systems at high frequencies. We were also able to demonstrate that the SaCas9 and SpCas9 proteins enhance homologous recombination via the induction of double-strand breaks only in the presence of their species-specific single guide (sg) RNAs. These proteins are not prone to inter-species interference with heterologous sgRNA expression constructs. Thus, the CRISPR/Cas systems of S. pyogenes and S. aureus should be appropriate for simultaneously addressing different sequence motifs with different enzyme activities in the same plant cell. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

  1. Sequences spanning the leader-repeat junction mediate CRISPR adaptation to phage in Streptococcus thermophilus

    Science.gov (United States)

    Wei, Yunzhou; Chesne, Megan T.; Terns, Rebecca M.; Terns, Michael P.

    2015-01-01

    CRISPR-Cas systems are RNA-based immune systems that protect prokaryotes from invaders such as phages and plasmids. In adaptation, the initial phase of the immune response, short foreign DNA fragments are captured and integrated into host CRISPR loci to provide heritable defense against encountered foreign nucleic acids. Each CRISPR contains a ∼100–500 bp leader element that typically includes a transcription promoter, followed by an array of captured ∼35 bp sequences (spacers) sandwiched between copies of an identical ∼35 bp direct repeat sequence. New spacers are added immediately downstream of the leader. Here, we have analyzed adaptation to phage infection in Streptococcus thermophilus at the CRISPR1 locus to identify cis-acting elements essential for the process. We show that the leader and a single repeat of the CRISPR locus are sufficient for adaptation in this system. Moreover, we identified a leader sequence element capable of stimulating adaptation at a dormant repeat. We found that sequences within 10 bp of the site of integration, in both the leader and repeat of the CRISPR, are required for the process. Our results indicate that information at the CRISPR leader-repeat junction is critical for adaptation in this Type II-A system and likely other CRISPR-Cas systems. PMID:25589547

  2. Microcalorimetric study of the growth of Streptococcus thermophilus in renneted milk

    Directory of Open Access Journals (Sweden)

    Irina eStulova

    2015-02-01

    Full Text Available The growth of Streptococcus thermophilus ST12 (ST12 in liquid milk, reconstituted from low-heat skim milk powder (RSM and in RSM with rennet addition (r-RSM at 40°C was monitored by microcalorimetry. It was shown that the growth rate of bacteria decreased in renneted samples in comparison with liquid RSM starting from certain sizes of the colonies (deviation moments, which depended on the inoculation rates. The hydrolysis of lactose was delayed for about 1 h in the r-RSM in comparison with RSM but otherwise the metabolism of carbohydrates in the renneted and non-renneted milks was similar. The total free amino acids content by the end of fermentations was higher in r-RSM than in RSM presumably due to the enzymatic hydrolytic activity of rennet. The quantitatively dominating amino acids were remarkably different in the r-RSM and RSM indicating that the hydrolysis cascade of caseins and/or metabolism of amino acids by the bacteria functioned differently in the two cases. The data obtained showed potential of microcalorimetry to characterize quantitative differences of growth and metabolism of the bacteria in renneted and liquid samples of milk.

  3. Sequences spanning the leader-repeat junction mediate CRISPR adaptation to phage in Streptococcus thermophilus.

    Science.gov (United States)

    Wei, Yunzhou; Chesne, Megan T; Terns, Rebecca M; Terns, Michael P

    2015-02-18

    CRISPR-Cas systems are RNA-based immune systems that protect prokaryotes from invaders such as phages and plasmids. In adaptation, the initial phase of the immune response, short foreign DNA fragments are captured and integrated into host CRISPR loci to provide heritable defense against encountered foreign nucleic acids. Each CRISPR contains a ∼100-500 bp leader element that typically includes a transcription promoter, followed by an array of captured ∼35 bp sequences (spacers) sandwiched between copies of an identical ∼35 bp direct repeat sequence. New spacers are added immediately downstream of the leader. Here, we have analyzed adaptation to phage infection in Streptococcus thermophilus at the CRISPR1 locus to identify cis-acting elements essential for the process. We show that the leader and a single repeat of the CRISPR locus are sufficient for adaptation in this system. Moreover, we identified a leader sequence element capable of stimulating adaptation at a dormant repeat. We found that sequences within 10 bp of the site of integration, in both the leader and repeat of the CRISPR, are required for the process. Our results indicate that information at the CRISPR leader-repeat junction is critical for adaptation in this Type II-A system and likely other CRISPR-Cas systems.

  4. Effects of Streptococcus thermophilus TH-4 in a rat model of doxorubicin-induced mucositis.

    Science.gov (United States)

    Wang, Hanru; Brook, Caitlin L; Whittaker, Alexandra L; Lawrence, Andrew; Yazbeck, Roger; Howarth, Gordon S

    2013-08-01

    Mucositis is a debilitating intestinal side effect of chemotherapeutic regimens. Probiotics have been considered a possible preventative treatment for mucositis. Streptococcus thermophilus TH-4 (TH-4), a newly identified probiotic, has been shown to partially alleviate mucositis induced by administration of the antimetabolite chemotherapy drug, methotrexate in rats; likely mediated through a mechanism of folate production. However, its effects against other classes of chemotherapy drug have yet to be determined. The authors investigated the effects of TH-4 in a rat model of mucositis induced by the anthracycline chemotherapy drug, doxorubicin. Gastrointestinal damage was induced in female Dark Agouti rats (148.3 ± 1.5 g) by intraperitoneal injection of doxorubicin (20 mg/kg). Animals recieved a daily oral gavage of TH-4 at 10(9) cfu/ml or skim milk (vehicle) from days 0 to 8. At day 6, rats were injected with either saline or doxorubicin. At kill, small intestinal tissues were collected for determination of sucrase and myeloperoxidase (MPO) activities and histological assessment. Body weight was significantly decreased by doxorubicin compared with normal controls (p loss of body weight induced by doxorubicin (2.3% compared with 4%), but provided no further therapeutic benefit. The minimal amelioration of doxorubicin-induced mucositis by TH-4 further supports folate production as a likely mechanism of TH-4 action against methotrexate-induced mucositis. Further studies into TH-4 are required to confirm its applicability to other conventional chemotherapy regimens.

  5. Control of EpsE, the phosphoglycosyltransferase initiating exopolysaccharide synthesis in Streptococcus thermophilus, by EpsD tyrosine kinase

    OpenAIRE

    Minic, Zoran; Marie, Corinne; Delorme, Christine; Faurie, Jean-Michel; Mercier, Gérald; Dusko Ehrlich, Stanislav

    2007-01-01

    We studied the roles of Streptococcus thermophilus phosphogalactosyltransferase (EpsE) (the priming enzyme), tyrosine kinase (EpsD), phosphatase (EpsB), and a membrane-associated protein with no known biochemical function (EpsC) in exopolysaccharide (EPS) synthesis. These proteins are well-conserved among bacteria and are usually encoded by clustered genes. Exopolysaccharide synthesis took place in the wild-type strain and a mutant lacking EpsB but not in mutants lacking EpsC, EpsD, or EpsE. ...

  6. Control of EpsE, the Phosphoglycosyltransferase Initiating Exopolysaccharide Synthesis in Streptococcus thermophilus, by EpsD Tyrosine Kinase▿

    OpenAIRE

    Minic, Zoran; Marie, Corinne; Delorme, Christine; Faurie, Jean-Michel; Mercier, Gérald; Ehrlich, Dusko; Renault, Pierre

    2006-01-01

    We studied the roles of Streptococcus thermophilus phosphogalactosyltransferase (EpsE) (the priming enzyme), tyrosine kinase (EpsD), phosphatase (EpsB), and a membrane-associated protein with no known biochemical function (EpsC) in exopolysaccharide (EPS) synthesis. These proteins are well-conserved among bacteria and are usually encoded by clustered genes. Exopolysaccharide synthesis took place in the wild-type strain and a mutant lacking EpsB but not in mutants lacking EpsC, EpsD, or EpsE. ...

  7. Comparison of the effect of green, white and black tea on Streptococcus thermophilus and Lactobacillus spp. in yogurt during refrigerated

    OpenAIRE

    Muniandy, Premalatha; Shori, Amal Bakr; Baba, Ahmad Salihin

    2017-01-01

    This study investigated the effects of green, white and black tea (Camellia sinensis) on lactic acid production and the viability of Streptococcus thermophilus and Lactobacillus spp. in yogurt during 3 weeks of refrigerated storage. Three types of tea water extracts were added into a milk-starter culture mixture and incubated at 42 °C until the pH was reduced to 4.5. All yogurts were then refrigerated (4 °C) for up to 21 days and samples were analyzed for pH, titratable acid and viable counts...

  8. Streptococcus thermophilus cell wall-anchored proteinase: release, purification, and biochemical and genetic characterization.

    Science.gov (United States)

    Fernandez-Espla, M D; Garault, P; Monnet, V; Rul, F

    2000-11-01

    Streptococcus thermophilus CNRZ 385 expresses a cell envelope proteinase (PrtS), which is characterized in the present work, both at the biochemical and genetic levels. Since PrtS is resistant to most classical methods of extraction from the cell envelopes, we developed a three-step process based on loosening of the cell wall by cultivation of the cells in the presence of glycine (20 mM), mechanical disruption (with alumina powder), and enzymatic treatment (lysozyme). The pure enzyme is a serine proteinase highly activated by Ca(2+) ions. Its activity was optimal at 37 degrees C and pH 7.5 with acetyl-Ala-Ala-Pro-Phe-paranitroanilide as substrate. The study of the hydrolysis of the chromogenic and casein substrates indicated that PrtS presented an intermediate specificity between the most divergent types of cell envelope proteinases from lactococci, known as the PI and PIII types. This result was confirmed by the sequence determination of the regions involved in substrate specificity, which were a mix between those of PI and PIII types, and also had unique residues. Sequence analysis of the PrtS encoding gene revealed that PrtS is a member of the subtilase family. It is a multidomain protein which is maturated and tightly anchored to the cell wall via a mechanism involving an LPXTG motif. PrtS bears similarities to cell envelope proteinases from pyogenic streptococci (C5a peptidase and cell surface proteinase) and lactic acid bacteria (PrtP, PrtH, and PrtB). The highest homologies were found with streptococcal proteinases which lack, as PrtS, one domain (the B domain) present in cell envelope proteinases from all other lactic acid bacteria.

  9. Comparison of the effect of green, white and black tea on Streptococcus thermophilus and Lactobacillus spp. in yogurt during refrigerated

    Directory of Open Access Journals (Sweden)

    Premalatha Muniandy

    2017-02-01

    Full Text Available This study investigated the effects of green, white and black tea (Camellia sinensis on lactic acid production and the viability of Streptococcus thermophilus and Lactobacillus spp. in yogurt during 3 weeks of refrigerated storage. Three types of tea water extracts were added into a milk-starter culture mixture and incubated at 42 °C until the pH was reduced to 4.5. All yogurts were then refrigerated (4 °C for up to 21 days and samples were analyzed for pH, titratable acid and viable counts of yogurt bacteria. Higher pH values (p  0.05 the viability of Lactobacillus spp. and S. thermophilus compared to PY during storage. All the three types of tea yogurt maintained a high level of S. thermophilus and Lactobacilllus spp. counts through refrigerated storage and this can ensure health benefits to be delivered to consumers on daily consumption.

  10. Comparison of statistical methods for identification of Streptococcus thermophilus, Enterococcus faecalis, and Enterococcus faecium from randomly amplified polymorphic DNA patterns.

    Science.gov (United States)

    Moschetti, G; Blaiotta, G; Villani, F; Coppola, S; Parente, E

    2001-05-01

    Thermophilic streptococci play an important role in the manufacture of many European cheeses, and a rapid and reliable method for their identification is needed. Randomly amplified polymorphic DNA (RAPD) PCR (RAPD-PCR) with two different primers coupled to hierarchical cluster analysis has proven to be a powerful tool for the classification and typing of Streptococcus thermophilus, Enterococcus faecium, and Enterococcus faecalis (G. Moschetti, G. Blaiotta, M. Aponte, P. Catzeddu, F. Villani, P. Deiana, and S. Coppola, J. Appl. Microbiol. 85:25-36, 1998). In order to develop a fast and inexpensive method for the identification of thermophilic streptococci, RAPD-PCR patterns were generated with a single primer (XD9), and the results were analyzed using artificial neural networks (Multilayer Perceptron, Radial Basis Function network, and Bayesian network) and multivariate statistical techniques (cluster analysis, linear discriminant analysis, and classification trees). Cluster analysis allowed the identification of S. thermophilus but not of enterococci. A Bayesian network proved to be more effective than a Multilayer Perceptron or a Radial Basis Function network for the identification of S. thermophilus, E. faecium, and E. faecalis using simplified RAPD-PCR patterns (obtained by summing the bands in selected areas of the patterns). The Bayesian network also significantly outperformed two multivariate statistical techniques (linear discriminant analysis and classification trees) and proved to be less sensitive to the size of the training set and more robust in the response to patterns belonging to unknown species.

  11. Mixed-culture transcriptome analysis reveals the molecular basis of mixed-culture growth in Streptococcus thermophilus and Lactobacillus bulgaricus.

    Science.gov (United States)

    Sieuwerts, Sander; Molenaar, Douwe; van Hijum, Sacha A F T; Beerthuyzen, Marke; Stevens, Marc J A; Janssen, Patrick W M; Ingham, Colin J; de Bok, Frank A M; de Vos, Willem M; van Hylckama Vlieg, Johan E T

    2010-12-01

    Many food fermentations are performed using mixed cultures of lactic acid bacteria. Interactions between strains are of key importance for the performance of these fermentations. Yogurt fermentation by Streptococcus thermophilus and Lactobacillus bulgaricus (basonym, Lactobacillus delbrueckii subsp. bulgaricus) is one of the best-described mixed-culture fermentations. These species are believed to stimulate each other's growth by the exchange of metabolites such as folic acid and carbon dioxide. Recently, postgenomic studies revealed that an upregulation of biosynthesis pathways for nucleotides and sulfur-containing amino acids is part of the global physiological response to mixed-culture growth in S. thermophilus, but an in-depth molecular analysis of mixed-culture growth of both strains remains to be established. We report here the application of mixed-culture transcriptome profiling and a systematic analysis of the effect of interaction-related compounds on growth, which allowed us to unravel the molecular responses associated with batch mixed-culture growth in milk of S. thermophilus CNRZ1066 and L. bulgaricus ATCC BAA-365. The results indicate that interactions between these bacteria are primarily related to purine, amino acid, and long-chain fatty acid metabolism. The results support a model in which formic acid, folic acid, and fatty acids are provided by S. thermophilus. Proteolysis by L. bulgaricus supplies both strains with amino acids but is insufficient to meet the biosynthetic demands for sulfur and branched-chain amino acids, as becomes clear from the upregulation of genes associated with these amino acids in mixed culture. Moreover, genes involved in iron uptake in S. thermophilus are affected by mixed-culture growth, and genes coding for exopolysaccharide production were upregulated in both organisms in mixed culture compared to monocultures. The confirmation of previously identified responses in S. thermophilus using a different strain combination

  12. Expression of the heat shock gene clpL of Streptococcus thermophilus is induced by both heat and cold shock

    Directory of Open Access Journals (Sweden)

    Naclerio Gino

    2006-02-01

    Full Text Available Abstract Background Heat and cold shock response are normally considered as independent phenomena. A small amount of evidence suggests instead that interactions may exist between them in two Lactococcus strains. Results We show the occurrence of molecular relationships between the mechanisms of cold and heat adaptations in Streptococcus thermophilus, a lactic acid bacterium widely used in dairy fermentation, where it undergoes both types of stress. We observed that cryotolerance is increased when cells are pre-incubated at high temperature. In addition, the production of a protein, identified as ClpL, a member of the heat-shock ATPase family Clp A/B, is induced at both high and low temperature. A knock-out clpL mutant is deficient in both heat and cold tolerance. However lack of production of this protein does not abolish the positive effect of heat pre-treatment towards cryotolerance. Conclusion Dual induction of ClpL by cold and heat exposure of cells and reduced tolerance to both temperature shocks in a clpL mutant indicates that the two stress responses are correlated in S. thermophilus. However this protein is not responsible by itself for cryotolerance of cells pre-treated at high temperature, indicating that ClpL is necessary for the two phenomena, but does not account by itself for the relationships between them.

  13. Optimization and effect of dairy industrial waste as media components in the production of hyaluronic acid by Streptococcus thermophilus.

    Science.gov (United States)

    Mohan, Naresh; Balakrishnan, Rengesh; Sivaprakasam, Senthilkumar

    2016-08-17

    Hyaluronic acid (HA) production using a dairy industrial waste is a more cost-efficient strategy than using an expensive synthetic medium. In this study, we investigated the production of HA using Streptococcus thermophilus under shake flask conditions using dairy industrial waste as nutritional supplements, namely whey permeate (WP) and whey protein hydrolysate (WPH). Preliminary screening using Plackett-Burman design exhibited WP, WPH, initial pH, and inoculum size as significant factors influencing HA titer. Response surface methodology design of four factors was formulated at three levels for enhanced production of HA. Shake flask HA fermentation by S. thermophilus was performed under global optimized process conditions and the optimal HA titer (342.93 mg L(-1)) corroborates with Box-Behnken design prediction. The molecular weight of HA was elucidated as 9.22-9.46 kDa. The ultralow-molecular weight HA reported in this study has a potential role in drug and gene delivery applications.

  14. Complete genome sequence of Streptococcus thermophilus MN-BM-A01, a strain with high exopolysaccharides production.

    Science.gov (United States)

    Bai, Ying; Sun, Erna; Shi, Yudong; Jiang, Yunyun; Chen, Yun; Liu, Songling; Zhao, Liang; Zhang, Ming; Guo, Huiyuan; Zhang, Hao; Mu, Zhishen; Ren, Fazheng

    2016-04-20

    Streptococcus thermophilus MN-BM-A01 (ST MN-BM-A01) (CGMCC No. 11383) was a strain isolated from Yogurt Block in Gansu, China. The yogurt fermented with this strain has good flavor, acidity, and viscosity. Moreover, ST MN-BM-A01 could produce a high level of EPS which can confer the yogurt with improved rheological properties. We reported the complete genome sequence of ST MN-BM-A01 that contains 1,876,516bp encoding 1704 coding sequences (CDSs), 67 tRNA genes and 6 rRNA operons. The genomic sequence indicated that this strain included a 35.3-kb gene cluster involved in EPS biosynthesis. Copyright © 2016. Published by Elsevier B.V.

  15. Streptococcus thermophilus APC151 strain is suitable for the manufacture of naturally GABA-enriched bioactive yoghurt

    Directory of Open Access Journals (Sweden)

    Daniel M. Linares

    2016-11-01

    Full Text Available Consumer interest in health-promoting food products is a major driving force for the increasing global demand of functional (probiotic dairy foods. Yoghurt is considered the ideal medium for delivery of beneficial functional ingredients. Gamma-amino-butyric acid has potential as a bioactive ingredient in functional foods due to its health-promoting properties as an anti-stress, anti-hypertensive and anti-diabetic agent. Here we report the use of a novel Streptococcus thermophilus strain, isolated from the digestive tract of fish, for production of yoghurt naturally enriched with 2 mg/ml of gamma-amino-butyric acid (250 mg in a standard yoghurt volume of 125 ml, a dose in the same range as that provided by some commercially available gamma-amino-butyric acid supplements. The biotechnological suitability of this strain for industrial production of yoghurt was demonstrated by comparison with the reference yoghurt inoculated with the commercial CH1 starter (Chr. Hansen widely used in the dairy industry. Both yoghurts showed comparable pH curves ΔpH/Δt = 0.31-0.33 h−1, viscosity 0.49 Pa.s, water holding capacity 72-73%, and chemical composition moisture (87-88 %, protein (5.05-5.65 %, fat (0.12-0.15 %, lactose (4.8-5.8 % and ash (0.74-1.2 %. Gamma-amino-butyric acid was not detected in the control yoghurt. In conclusion, the S. thermophilus APC151 strain reported here provides a natural means for fortification of yoghurt with gamma-amino-butyric acid.

  16. Streptococcus thermophilus APC151 Strain Is Suitable for the Manufacture of Naturally GABA-Enriched Bioactive Yogurt

    Science.gov (United States)

    Linares, Daniel M.; O’Callaghan, Tom F.; O’Connor, Paula M.; Ross, R. P.; Stanton, Catherine

    2016-01-01

    Consumer interest in health-promoting food products is a major driving force for the increasing global demand of functional (probiotic) dairy foods. Yogurt is considered the ideal medium for delivery of beneficial functional ingredients. Gamma-amino-butyric acid has potential as a bioactive ingredient in functional foods due to its health-promoting properties as an anti-stress, anti-hypertensive, and anti-diabetic agent. Here, we report the use of a novel Streptococcus thermophilus strain, isolated from the digestive tract of fish, for production of yogurt naturally enriched with 2 mg/ml of gamma-amino-butyric acid (200 mg in a standard yogurt volume of 100 ml), a dose in the same range as that provided by some commercially available gamma-amino-butyric acid supplements. The biotechnological suitability of this strain for industrial production of yogurt was demonstrated by comparison with the reference yogurt inoculated with the commercial CH1 starter (Chr. Hansen) widely used in the dairy industry. Both yogurts showed comparable pH curves [ΔpH/Δt = 0.31-0.33 h-1], viscosity [0.49 Pa-s], water holding capacity [72–73%], and chemical composition [moisture (87–88%), protein (5.05–5.65%), fat (0.12–0.15%), sugar (4.8–5.8%), and ash (0.74–1.2%)]. Gamma-amino-butyric acid was not detected in the control yogurt. In conclusion, the S. thermophilus APC151 strain reported here provides a natural means for fortification of yogurt with gamma-amino-butyric acid. PMID:27920772

  17. Streptococcus thermophilus APC151 Strain Is Suitable for the Manufacture of Naturally GABA-Enriched Bioactive Yogurt.

    Science.gov (United States)

    Linares, Daniel M; O'Callaghan, Tom F; O'Connor, Paula M; Ross, R P; Stanton, Catherine

    2016-01-01

    Consumer interest in health-promoting food products is a major driving force for the increasing global demand of functional (probiotic) dairy foods. Yogurt is considered the ideal medium for delivery of beneficial functional ingredients. Gamma-amino-butyric acid has potential as a bioactive ingredient in functional foods due to its health-promoting properties as an anti-stress, anti-hypertensive, and anti-diabetic agent. Here, we report the use of a novel Streptococcus thermophilus strain, isolated from the digestive tract of fish, for production of yogurt naturally enriched with 2 mg/ml of gamma-amino-butyric acid (200 mg in a standard yogurt volume of 100 ml), a dose in the same range as that provided by some commercially available gamma-amino-butyric acid supplements. The biotechnological suitability of this strain for industrial production of yogurt was demonstrated by comparison with the reference yogurt inoculated with the commercial CH1 starter (Chr. Hansen) widely used in the dairy industry. Both yogurts showed comparable pH curves [ΔpH/Δt = 0.31-0.33 h(-1)], viscosity [0.49 Pa-s], water holding capacity [72-73%], and chemical composition [moisture (87-88%), protein (5.05-5.65%), fat (0.12-0.15%), sugar (4.8-5.8%), and ash (0.74-1.2%)]. Gamma-amino-butyric acid was not detected in the control yogurt. In conclusion, the S. thermophilus APC151 strain reported here provides a natural means for fortification of yogurt with gamma-amino-butyric acid.

  18. Influence of organic buffers on bacteriocin production by Streptococcus thermophilus ST110.

    Science.gov (United States)

    Somkuti, George A; Gilbreth, Stefanie E

    2007-08-01

    The effect of the organic buffer salts MES, MOPS, and PIPES on the growth of S. thermophilus ST110, medium pH, and accumulation of the antipediococcal bacteriocin thermophilin 110 were evaluated in whey permeate media over a period of 24 h. In nonbuffered medium, thermophilin 110 production at 37 degrees C paralleled the growth of S. thermophilus ST110 and reached a maximum after 8-10 h. Addition of organic buffer salts decreased the drop in medium pH and resulted in increased biomass (dry cells; microg/mL) and higher yields of thermophilin 110 (units/microg cells). The best results were obtained by the addition of 1% (w/v) MES to the medium, which reduced the pH drop to 1.8 units after 10 h of growth (compared to 2.3 pH units in the control) and resulted in a 1.5-fold increase in cell mass (495 microg/mL) and a 7-fold increase in thermophilin 110 yield (77 units/microg dry cells) over the control. The results showed that whey permeate-based media may be suitable for producing large amounts of thermophilin 110 needed for controlling spoilage pediococci in industrial wine and beer fermentations.

  19. Production of the exopolysaccharides by Streptococcus thermophilus: effect of growth conditions on fermentation kinetics and intrinsic viscosity.

    Science.gov (United States)

    Shene, C; Canquil, N; Bravo, S; Rubilar, M

    2008-06-10

    Production of exopolysaccharides (EPS) by a commercial Streptococcus thermophilus strain was evaluated at different growth conditions [temperature (32-45 degrees C), carbon source and initial nitrogen (N) content]. Lactose from deproteinized whey and sucrose allowed to obtain EPS yields higher than 1200 mg/mM of the consumed carbon source. Intrinsic viscosity of the EPS was significantly reduced by ionic strength indicating a polyelectrolyte behavior. Growth conditions used for the production of the EPS had a significant effect (pfermentations carried out at different temperatures specific EPS synthesis rate was positive and linearly associated with the specific lactose consumption rate (R2=0.967) and specific galactose production rate (R2=0.967). Critical coil overlap parameter, [eta]C*, for the EPS produced in the lactose fermentations carried out at 43 and 45 degrees C was determined to be approximately 7.6, and their critical overlap concentrations (C*) were 0.45 and 0.87 g/dL, respectively.

  20. Whey protein isolate improves acid and bile tolerances of Streptococcus thermophilus ST-M5 and Lactobacillus delbrueckii ssp. bulgaricus LB-12.

    Science.gov (United States)

    Vargas, Luis A; Olson, Douglas W; Aryana, Kayanush J

    2015-04-01

    Acid tolerance and bile tolerance are important probiotic characteristics. Whey proteins contain branched-chain amino acids, which play a role in muscle building and are popular among athletes. Increasing emphasis is being placed on diets containing less carbohydrate, less fat, and more protein. The effect of incremental additions of whey protein isolate (WPI) on probiotic characteristics of pure cultures is not known. The objective of this study was to determine the influence of added WPI on acid tolerance and bile tolerance of pure cultures of Streptococcus thermophilus ST-M5 and Lactobacillus bulgaricus LB-12. The WPI was used at 0 (control), 1, 2 and 3% (wt/vol). Assessment of acid tolerance was conducted on pure cultures at 30-min intervals for 2h of acid exposure and bile tolerance at 1-h intervals for 5h of bile exposure. Use of 1, 2, and 3% WPI improved acid tolerance of Strep. thermophilus ST-M5 and Lb. bulgaricus LB-12. The highest counts for acid tolerance of Strep. thermophilus ST-M5 and Lb. bulgaricus LB-12 were obtained when 3% WPI was used. Use of 2 and 3% WPI improved bile tolerance of Strep. thermophilus ST-M5 and Lb. bulgaricus LB-12 over 5h of bile exposure. The use of WPI is recommended to improve acid and bile tolerance of the yogurt culture bacteria Strep. thermophilus ST-M5 and Lb. bulgaricus LB-12. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  1. Transcriptomic and metabolic responses of Staphylococcus aureus in mixed culture with Lactobacillus plantarum, Streptococcus thermophilus and Enterococcus durans in milk.

    Science.gov (United States)

    Zdenkova, Kamila; Alibayov, Babek; Karamonova, Ludmila; Purkrtova, Sabina; Karpiskova, Renata; Demnerova, Katerina

    2016-09-01

    Staphylococcus aureus is a major food-borne pathogen due to the production of enterotoxin and is particularly prevalent in contaminated milk and dairy products. The lactic acid bacteria (LAB) are widely used as biocontrol agents in fermented foods which can inhibit pathogenic flora. In our work, we investigated the influence of three strains of LAB (Lactobacillus plantarum, Streptococcus thermophilus and Enterococcus durans) on the relative expression of three enterotoxin genes (sea, sec, sell) and eight virulence and/or regulatory genes (sarA, saeS, codY, srrA, rot, hld/RNAIII, agrA/RNAII, sigB) in two S. aureus strains (MW2 and Sa1612) in TSB and reduced-fat milk (1.5 %) at 30 °C over a 24-h period. The tested LAB and S. aureus strains proved to be mutually non-competitive or only slightly competitive during co-cultivation. In addition, under the above-mentioned conditions, differential gene expression between the S. aureus MW2 and Sa1612 strains was well documented. S. aureus growth was changed in mixed culture with LAB; however, its effect on the repression of sea and sec expression correlated with production of these virulence factors. In comparison, the presence of LAB strains generally inhibited the expression of sec, sell, sarA, seaS, agrA/RNAII and hld/RNAIII genes. The effect of LAB strains presence on the expression of sea, codY, srrA, rot and sigB genes was medium, time, LAB and S. aureus strain specific. SEA and SEC production was significantly reduced in milk compared to TSB in pure culture. After the 24-h cultivation, S. aureus MW2 and Sa1612 SEC production was 187 and 331 times lower in milk compared to TSB, respectively (0.07 and 0.39 ng/mL in milk, versus 13.1 and 129.2 ng/mL in TSB, respectively). At the same time S. aureus MW2 and Sa1612 SEA production was 77 and 68 times lower in milk compared to TSB, respectively (0.99 and 0.17 ng/mL in milk, versus 76.4 and 11.5 ng/mL in TSB, respectively). This study has revealed new insights into the

  2. Biofilm Formation on Stainless Steel by Streptococcus thermophilus UC8547 in Milk Environments Is Mediated by the Proteinase PrtS.

    Science.gov (United States)

    Bassi, D; Cappa, F; Gazzola, S; Orrù, L; Cocconcelli, P S

    2017-04-15

    In Streptococcus thermophilus , gene transfer events and loss of ancestral traits over the years contribute to its high level of adaptation to milk environments. Biofilm formation capacity, a phenotype that is lost in the majority of strains, plays a role in persistence in dairy environments, such as milk pasteurization and cheese manufacturing plants. To investigate this property, we have studied S. thermophilus UC8547, a fast-acidifying dairy starter culture selected for its high capacity to form biofilm on stainless steel under environmental conditions resembling the dairy environment. Using a dynamic flow cell apparatus, it was shown that S. thermophilus UC8547 biofilm formation on stainless steel depends on the presence of milk proteins. From this strain, which harbors the prtS gene for the cell wall protease and shows an aggregative phenotype, spontaneous mutants with impaired biofilm capacity can be isolated at high frequency. These mutants lack the PrtS expendable island, as confirmed by comparison of the genome sequence of UC8547Δ3 with that of the parent strain. The prtS island excision occurs between two 26-bp direct repeats located in the two copies of the IS Sth1 flanking this genomic island. The central role of PrtS was confirmed by analyzing the derivative strain UC8547Δ16, whose prtS gene was interrupted by an insertional mutation, thereby making it incapable of biofilm formation. PrtS, acting as a binding substance between the milk proteins adhered to stainless steel and S. thermophilus cell envelopes, mediates biofilm formation in dairy environments. This feature provides S. thermophilus with an ecological benefit for its survival and persistence in this environment. IMPORTANCE The increased persistence of S. thermophilus biofilm has consequences in the dairy environment: if, on the one hand, the release of this microorganism from biofilm can promote the fermentation of artisanal cheeses, under industrial conditions it may lead to undesirable

  3. Use of microparticulated whey protein concentrate, exopolysaccharide-producing Streptococcus thermophilus, and adjunct cultures for making low-fat Italian Caciotta-type cheese

    OpenAIRE

    Di Cagno, R.; De Pasquale, I.; De Angelis, M.; Buchin, Solange; Rizzello, C. G.; Gobbetti, M

    2014-01-01

    Low-fat Caciotta-type cheeses were manufactured with partially skim milk (fat content of similar to 0.3%) alone (LFC); with the supplementation of 0.5% (wt/vol) microparticulated whey protein concentrate (MWPC) (LFC-MWPC); with MWPC and exopolysaccharides (EPS)-producing Streptococcus thermophilus ST446 (LFC-MWPC-EPS); and with MWPC, EPS-producing strain ST446, and Lactobacillus plantarum LP and Lactobacillus rhamnosus LRA as adjunct cultures (LFC-MWPC-EPS-A). The non-EPS-producing isogenic v...

  4. Preparation of Acid-Resistant Microcapsules with Shell-Matrix Structure to Enhance Stability of Streptococcus Thermophilus IFFI 6038.

    Science.gov (United States)

    Zhou, Huan Bin; Chen, Jiashu; Li, Shunyi; Zhang, Jianpan; Zhu, Chun E; Ran, Hao; Luo, Meihua; Pan, Xin; Hu, Haiyan; Wu, Chuanbin

    2017-08-01

    Microencapsulation is an effective technology used to protect probiotics against harsh conditions. Extrusion is a commonly used microencapsulation method utilized to prepare probiotics microcapsules that is regarded as economical and simple to operate. This research aims to prepare acid-resistant probiotic microcapsules with high viability after freeze-drying and optimized storage stability. Streptococcus thermophilus IFFI 6038 (IFFI 6038) cells were mixed with trehalose and alginate to fabricate microcapsules using extrusion. These capsules were subsequently coated with chitosan to obtain chitosan-trehalose-alginate microcapsules with shell-matrix structure. Chitosan-alginate microcapsules (without trehalose) were also prepared using the same method. The characteristics of the microcapsules were observed by measuring the freeze-dried viability, acid resistance, and long-term storage stability of the cells. The viable count of IFFI 6038 in the chitosan-trehalose-alginate microcapsules was 8.34 ± 0.30 log CFU g -1 after freeze-drying (lyophilization), which was nearly 1 log units g -1 greater than the chitosan-alginate microcapsules. The viability of IFFI 6038 in the chitosan-trehalose-alginate microcapsules was 6.45 ± 0.09 log CFU g -1 after 120 min of treatment in simulated gastric juices, while the chitosan-alginate microcapsules only measured 4.82 ± 0.22 log CFU g -1 . The results of the long-term storage stability assay indicated that the viability of IFFI 6038 in chitosan-trehalose-alginate microcapsules was higher than in chitosan-alginate microcapsules after storage at 25 °C. Trehalose played an important role in the stability of IFFI 6038 during storage. The novel shell-matrix chitosan-trehalose-alginate microcapsules showed optimal stability and acid resistance, demonstrating their potential as a delivery vehicle to transport probiotics. © 2017 Institute of Food Technologists®.

  5. Dairy Streptococcus thermophilus improves cell viability of Lactobacillus brevis NPS-QW-145 and its γ-aminobutyric acid biosynthesis ability in milk.

    Science.gov (United States)

    Wu, Qinglong; Law, Yee-Song; Shah, Nagendra P

    2015-08-06

    Most high γ-aminobutyric acid (GABA) producers are Lactobacillus brevis of plant origin, which may be not able to ferment milk well due to its poor proteolytic nature as evidenced by the absence of genes encoding extracellular proteinases in its genome. In the present study, two glutamic acid decarboxylase (GAD) genes, gadA and gadB, were found in high GABA-producing L. brevis NPS-QW-145. Co-culturing of this organism with conventional dairy starters was carried out to manufacture GABA-rich fermented milk. It was observed that all the selected strains of Streptococcus thermophilus, but not Lactobacillus delbrueckii subsp. bulgaricus, improved the viability of L. brevis NPS-QW-145 in milk. Only certain strains of S. thermophilus improved the gadA mRNA level in L. brevis NPS-QW-145, thus enhanced GABA biosynthesis by the latter. These results suggest that certain S. thermophilus strains are highly recommended to co-culture with high GABA producer for manufacturing GABA-rich fermented milk.

  6. Selective and differential enumerations of Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus thermophilus, Lactobacillus acidophilus, Lactobacillus casei and Bifidobacterium spp. in yoghurt--a review.

    Science.gov (United States)

    Ashraf, Rabia; Shah, Nagendra P

    2011-10-03

    Yoghurt is increasingly being used as a carrier of probiotic bacteria for their potential health benefits. To meet with a recommended level of ≥10(6) viable cells/g of a product, assessment of viability of probiotic bacteria in market preparations is crucial. This requires a working method for selective enumeration of these probiotic bacteria and lactic acid bacteria in yoghurt such as Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, Lb. acidophilus, Lb. casei and Bifidobacterium. This chapter presents an overview of media that could be used for differential and selective enumerations of yoghurt bacteria. De Man Rogosa Sharpe agar containing fructose (MRSF), MRS agar pH 5.2 (MRS 5.2), reinforced clostridial prussian blue agar at pH 5.0 (RCPB 5.0) or reinforced clostridial agar at pH 5.3 (RCA 5.3) are suitable for enumeration of Lb. delbrueckii subsp. bulgaricus when the incubation is carried out at 45°C for 72h. S. thermophilus (ST) agar and M17 are recommended for selective enumeration of S. thermophilus. Selective enumeration of Lb. acidophilus in mixed culture could be made in Rogosa agar added with 5-bromo-4-chloro-3-indolyl-β-d-glucopyranoside (X-Glu) or MRS containing maltose (MRSM) and incubation in a 20% CO2 atmosphere. Lb. casei could be selectively enumerated on specially formulated Lb. casei (LC) agar from products containing yoghurt starter bacteria (S. thermophilus and Lb. delbrueckii subsp. bulgaricus), Lb. acidophilus, Bifidobacterium spp. and Lb. casei. Bifidobacterium could be enumerated on MRS agar supplemented with nalidixic acid, paromomycin, neomycin sulphate and lithium chloride (MRS-NPNL) under anaerobic incubation at 37°C for 72h. Copyright © 2011. Published by Elsevier B.V.

  7. Novel Variants of Streptococcus thermophilus Bacteriophages Are Indicative of Genetic Recombination among Phages from Different Bacterial Species

    DEFF Research Database (Denmark)

    Szymczak, Paula; Janzen, Thomas; Neves, Ana Rute

    2017-01-01

    shorter tails than the traditional S. thermophilus phages. The third phage, CHPC1151, had a tail size similar to those of the cos- or pac-type phages, but it displayed a different baseplate structure. Sequencing analysis revealed the genetic similarity of CHPC577 and CHPC926 with a subgroup of Lactococcus...... the possibility of cross-interactions. Our data indicated that the use of S. thermophilus together with L. lactis, extensively applied for dairy fermentations, triggered the recombination between phages infecting different bacterial species. A notable diversity among S. thermophilus phage populations requires...

  8. Impact of engineered Streptococcus thermophilus trains overexpressing glyA gene on folic acid and acetaldehyde production in fermented milk Impacto de linhagens de Streptococcus thermophilus com aumento da expressão do gene glyA na produção de ácido folico e acetaldeído em leite fermentado

    Directory of Open Access Journals (Sweden)

    Ana Carolina Sampaio Dória Chaves

    2003-11-01

    Full Text Available The typical yogurt flavor is caused by acetaldehyde produced through many different pathways by the yogurt starter bacteria L. bulgaricus and S. thermophilus. The attention was focused on one specific reaction for acetaldehyde and folic acid formation catalyzed by serine hydroxymethyltransferase (SHMT, encoded by the glyA gene. In S. thermophilus, this enzyme SHMT also plays the typical role of the enzyme threonine aldolase (TA that is the interconvertion of threonine into glycine and acetaldehyde. The behavior of engineered S. thermophilus strains in milk fermentation is described, folic acid and acetaldehyde production were measured and pH and counts were followed. The engineered S. thermophilus strains StA2305 and StB2305, have the glyA gene (encoding the enzyme serine hydroxymethyltransferase overexpressed. These engineered strains showed normal growth in milk when it was supplemented with Casitione. When they were used in milk fermentation it was observed an increase in folic acid and in acetaldehyde production by StA2305 and for StB2305 it was noticed a significative increase in folic acid formation.O acetaldeído, responsável pelo sabor e aroma característicos de iogurte, é produzido por diferentes vias metabólicas pelas bactérias lácticas: Streptococcus thermophilus (S. thermophilus e Lactobacillus delbrueckii subsp. bulgaricus (L. bulgaricus. Neste trabalho, a atenção foi focada especificamente na reação para a formação de acetaldeído e de ácido fólico, catalisada pela enzima serina hidroximetil transferase (SHMT, codificada pelo gene glyA. A enzima SHMT catalisa diversas reações e, no caso da bactéria S. thermophilus, ela exerce também a atividade característica da enzima treonina aldolase (TA, definida como a interconversão do aminoácido treonina em glicina e acetaldeído. Foram construídas linhagens de S. thermophilus (StA2305 e StB2305 com super expressão do gene glyA. Estas linhagens modificadas apresentaram

  9. Control of Lactose Transport, β-Galactosidase Activity, and Glycolysis by CcpA in Streptococcus thermophilus : Evidence for Carbon Catabolite Repression by a Non-Phosphoenolpyruvate-Dependent Phosphotransferase System Sugar

    NARCIS (Netherlands)

    Bogaard, Patrick T.C. van den; Kleerebezem, Michiel; Kuipers, Oscar P.; Vos, Willem M. de

    2000-01-01

    Streptococcus thermophilus, unlike many other gram-positive bacteria, prefers lactose over glucose as the primary carbon and energy source. Moreover, lactose is not taken up by a phosphoenolpyruvate-dependent phosphotransferase system (PTS) but by the dedicated transporter LacS. In this paper we

  10. Antibiotic Resistance-Susceptibility Profiles of Streptococcus thermophilus Isolated from Raw Milk and Genome Analysis of the Genetic Basis of Acquired Resistances

    Directory of Open Access Journals (Sweden)

    Ana B. Flórez

    2017-12-01

    Full Text Available The food chain is thought to play an important role in the transmission of antibiotic resistances from commensal and beneficial bacteria to pathogens. Streptococcus thermophilus is a lactic acid bacterium of major importance as a starter for the dairy industry. This study reports the minimum inhibitory concentration (MIC of 16 representative antimicrobial agents to 41 isolates of S. thermophilus derived from raw milk. Strains showing resistance to tetracycline (seven, erythromycin and clindamycin (two, and streptomycin and neomycin (one were found. PCR amplification identified tet(S in all the tetracycline-resistant strains, and ermB in the two erythromycin/clindamycin-resistant strains. Hybridisation experiments suggested each resistance gene to be located in the chromosome with a similar genetic organization. Five antibiotic-resistant strains -two resistant to tetracycline (St-2 and St-9, two resistant to erythromycin/clindamycin (St-5 and St-6, and one resistant to streptomycin/neomycin (St-10- were subjected to genome sequencing and analysis. The tet(S gene was identified in small contigs of 3.2 and 3.7 kbp in St-2 and St-9, respectively, flanked by truncated copies of insertion sequence (IS elements. Similarly, ermB in St-6 and St-5 was found in contigs of 1.6 and 28.1 kbp, respectively. Sequence analysis and comparison of the largest contig showed it to contain three segments (21.9, 3.7, and 1.4 kbp long highly homologous to non-collinear sequences of pRE25 from Enterococcus faecalis. These segments contained the ermB gene, a transference module with an origin of transfer (oriT plus 15 open reading frames encoding proteins involved in conjugation, and modules for plasmid replication and segregation. Homologous stretches were separated by short, IS-related sequences, resembling the genetic organization of the integrative and conjugative elements (ICEs found in Streptococcus species. No gene known to provide aminoglycoside resistance was

  11. EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2014. Scientific Opinion on the substantiation of a health claim related to beta-galactosidase from Streptococcus thermophilus and reduction of gastrointestinal discomfort pursuant to Article 14 of Regulation (EC) No 1924/2006

    DEFF Research Database (Denmark)

    Tetens, Inge

    2014-01-01

    to deliver an opinion on the scientific substantiation of a health claim related to beta-galactosidase from Streptococcus thermophilus and reduction of gastrointestinal discomfort. According to the applicant, the food constituent which is the subject of the claim is beta-galactosidase from Streptococcus...... thermophilus. Streptococcus thermophilus is added to infant formulae in the production process for fermentation purposes and the live organisms are inactivated after the fermentation process. The Panel considers that the food constituent, beta-galactosidase from Streptococcus thermophilus, under the conditions...... is a beneficial physiological effect. No human studies from which conclusions could be drawn for the scientific substantiation of the claim were provided by the applicant. The Panel concludes that a cause and effect relationship has not been established between the consumption of beta-galactosidase which...

  12. Ekzopolisakkarit Üreticisi Streptococcus Thermophilus ST8.01 Suşu; Potansiyel Probiyotik Kültür (İngilizce

    Directory of Open Access Journals (Sweden)

    Banu Özden Tuncer

    2015-02-01

    Full Text Available Bu çalışmanın amacı, ekzopolisakkarit (EPS üreticisi Streptococcus thermophilus ST8.01 suşunun probiyotik potansiyelinin belirlenmesidir. Bu suş pH 3 ve %1 safra tuzunda hayatta kalma yeteneğine sahiptir. %0.4 fenol ve pH’sı 3’e ayarlanmış mide suyu uygulaması sonrası canlı hücre sayısı sırasıyla 4.80±0.04 ve 2.11±0.06 log kob/mL olarak ölçülmüştür. Strep. thermophilus ST8.01, 100 mg/L lizozim konsantrasyonunda gelişebilme ve yüksek otoagregasyon (%49.55±6.24 ve hidrofobisite (%67.23±7.16 yeteneğine sahiptir. ST8.01 suşu aynı zamanda klinik olarak önemli olan antibiyotiklere karşı duyarlı bulunmuştur. Bu araştırmadan elde edilen sonuçlar, Strep. thermophilus ST8.01 suşunun süt ürünleri üretiminde probiyotik starter kültür olarak kullanılabileceğini düşündürmektedir.

  13. Quantitative analysis of the lactic acid and acetaldehyde produced by Streptococcus thermophilus and Lactobacillus bulgaricus strains isolated from traditional Turkish yogurts using HPLC.

    Science.gov (United States)

    Gezginc, Y; Topcal, F; Comertpay, S; Akyol, I

    2015-03-01

    The present study was conducted to evaluate the lactic acid- and acetaldehyde-producing abilities of lactic acid bacterial species isolated from traditionally manufactured Turkish yogurts using HPLC. The lactic acid bacterial species purified from the yogurts were the 2 most widely used species in industrial yogurt production: Streptococcus thermophilus and Lactobacillus bulgaricus. These bacteria have the ability to ferment hexose sugars homofermentatively to generate lactic acid and some carbonyl compounds, such as acetaldehyde through pyruvate metabolism. The levels of the compounds produced during fermentation influence the texture and the flavor of the yogurt and are themselves influenced by the chemical composition of the milk, processing conditions, and the metabolic activity of the starter culture. In the study, morphological, biochemical, and molecular characteristics were employed to identify the bacteria obtained from homemade yogurts produced in different regions of Turkey. A collection of 91 Strep. thermophilus and 35 L. bulgaricus strains were investigated for their lactic acid- and acetaldehyde-formation capabilities in various media such as cow milk, LM17 agar, and aerobic-anaerobic SM17 agar or de Man, Rogosa, and Sharpe agar. The amounts of the metabolites generated by each strain in all conditions were quantified by HPLC. The levels were found to vary depending on the species, the strain, and the growth conditions used. Whereas lactic acid production ranged between 0 and 77.9 mg/kg for Strep. thermophilus strains, it ranged from 0 to 103.5 mg/kg for L. bulgaricus. Correspondingly, the ability to generate acetaldehyde ranged from 0 to 105.9 mg/kg in Strep. thermophilus and from 0 to 126.9 mg/kg in L. bulgaricus. Our study constitutes the first attempt to determine characteristics of the wild strains isolated from traditional Turkish yogurts, and the approach presented here, which reveals the differences in metabolite production abilities of the

  14. Sequencing and transcriptional analysis of the Streptococcus thermophilus histamine biosynthesis gene cluster: factors that affect differential hdcA expression

    DEFF Research Database (Denmark)

    Calles-Enríquez, Marina; Hjort, Benjamin Benn; Andersen, Pia Skov

    2010-01-01

    acquisition through a horizontal transfer mechanism. Transcriptional analysis of the hdc cluster revealed the existence of a polycistronic mRNA covering the three genes. The histidine-decarboxylating gene (hdcA) of S. thermophilus demonstrated maximum expression during the stationary growth phase, with high...... to produce histamine. The hdc clusters of S. thermophilus CHCC1524 and CHCC6483 were sequenced, and the factors that affect histamine biosynthesis and histidine-decarboxylating gene (hdcA) expression were studied. The hdc cluster began with the hdcA gene, was followed by a transporter (hdcP), and ended...... with the hdcB gene, which is of unknown function. The three genes were orientated in the same direction. The genetic organization of the hdc cluster showed a unique organization among the lactic acid bacterial group and resembled those of Staphylococcus and Clostridium species, thus indicating possible...

  15. Adesão de linhagem selvagem de Streptococcus thermophilus em superfície de aço inoxidável e efeitos da higienização na sua remoção Adhesion of a wild strain of Streptococcus thermophilus onto stainless steel surfaces and the effects of cleaning and sanification on its removal

    Directory of Open Access Journals (Sweden)

    Ana Lourdes Neves GÂNDARA

    2000-04-01

    Full Text Available Linhagem selvagem de Streptococcus thermophilus isolada de leite pasteurizado foi avaliada em modelo experimental quanto a adesão em superfície de aço inoxidável e comportamento frente à limpeza e sanificação. Em leite, a adesão do microrganismo em aço inoxidável foi estudada em 6h de contato a 45°C sob agitação e uma higienização com detergentes alcalino e ácido seguida de sanificação foi utilizada para avaliação do comportamento das células aderidas frente à higienização. Esse microrganismo aderiu a essa superfície produzindo uma carga de 10(4UFC/cm². Após a limpeza alcalina não foram detectadas células aderidas; em seguida a limpeza ácida 6 UFC/cm² ainda foram detectadas. A sanificação com hipoclorito de sódio, após a limpeza, foi suficiente para reduzir a carga de S. thermophilus selvagem aderida ao aço inoxidável. O modelo experimental mostrou-se adequado para o estudo, indicando que a cultura selvagem de Streptococcus thermophilus é produtora de biofilme em superfície de aço inoxidável. A limpeza da superfície de aço inoxidável por detergência alcalina remove mais que 99,9% das células aderidas. Pequenos números de células remanescentes são removidos na detergência ácida o que demonstra a necessidade das diferentes etapas e tipos de detergentes para a eficiência da limpeza. Melhores resultados na remoção desse biofilme são alcançadas com detergência alcalina seguida de detergência ácida e mais eficientemente quando se utiliza uma sanificação complementar com hipoclorito de sódio.A wild strain of Streptococcus thermophilus isolated from pasteurized milk was evaluated using an experimental model with respect to its adhesion onto stainless steel surfaces and its behaviour when submitted to cleansing and sanification. In milk, the adhesion of the microorganism on to stainless steel surfaces was studied after 6 hours of contact at 45°C with agitation, and after a cleansing process

  16. Phage-Induced Expression of CRISPR-Associated Proteins is Revealed by Shotgun Proteomics in Streptococcus thermophilus

    Energy Technology Data Exchange (ETDEWEB)

    Young, Jacque C [ORNL; Dill, Brian [ORNL; Pan, Chongle [ORNL; Hettich, Robert {Bob} L [ORNL; Banfield, Jillian F. [University of California, Berkeley; Shah, Manesh B [ORNL; Fremaux, Christophe [Danisco France SAS; Horvath, Philippe [Danisco France SAS; Barrangou, Rodolphe [Danisco USA; Verberkmoes, Nathan C [ORNL

    2012-01-01

    The CRISPR/Cas system, comprised of clustered regularly interspaced short palindromic repeats along with their associated (Cas) proteins, protects bacteria and archaea from viral predation and invading nucleic acids. While the mechanism of action for this acquired immunity is currently under investigation, the response of Cas protein expression to phage infection has yet to be elucidated. In this study, we employed shotgun proteomics to measure the global proteome expression in a model system for studying the CRISPR/Cas response: infection of S. thermophilus DGCC7710 with phage 2972. Host and viral proteins were simultaneously measured following inoculation at two different multiplicities of infection and across various time points using two-dimensional liquid chromatography tandem mass spectroscopy. Thirty-seven out of forty predicted viral proteins were detected, including all proteins of the structural virome and viral effector proteins. In total, 1,013 of 2,079 predicted S. thermophilus proteins were detected, facilitating the monitoring of host protein synthesis changes in response to virus infection. Importantly, Cas proteins from all four CRISPR loci in the S. thermophilus DGCC7710 genome were detected, including loci previously thought to be inactive. Many Cas proteins were found to be constitutively expressed, but several demonstrated increased abundance during peak infection, including the Cas9 proteins from the CRISPR1 and CRISPR3 loci, which are key players in the interference phase of the CRISPR/Cas response. Altogether, these results provide novel insights into the proteomic response of S. thermophilus, specifically CRISPR-associated proteins, upon phage 2972 infection.

  17. Probiotic Streptococcus thermophilus FP4 and Bifidobacterium breve BR03 Supplementation Attenuates Performance and Range-of-Motion Decrements Following Muscle Damaging Exercise

    Directory of Open Access Journals (Sweden)

    Ralf Jäger

    2016-10-01

    Full Text Available Probiotics have immunomodulatory effects. However, little is known about the potential benefit of probiotics on the inflammation subsequent to strenuous exercise. In a double-blind, randomized, placebo controlled, crossover design separated by a 21-day washout, 15 healthy resistance-trained men ingested an encapsulated probiotic Streptococcus (S. thermophilus FP4 and Bifidobacterium (B. breve BR03 at 5 bn live cells (AFU concentration each, or a placebo, daily for 3 weeks prior to muscle-damaging exercise (ClinicalTrials.gov NCT02520583. Isometric strength, muscle soreness, range of motion and girth, and blood interleukin-6 (IL-6 and creatine kinase (CK concentrations were measured from pre- to 72 h post-exercise. Statistical analysis was via mixed models and magnitude-based inference to the standardized difference. Probiotic supplementation resulted in an overall decrease in circulating IL-6, which was sustained to 48 h post-exercise. In addition, probiotic supplementation likely enhanced isometric average peak torque production at 24 to 72 h into the recovery period following exercise (probiotic–placebo point effect ±90% CI: 24 h, 11% ± 7%; 48 h, 12% ± 18%; 72 h, 8% ± 8%. Probiotics also likely moderately increased resting arm angle at 24 h (2.4% ± 2.0% and 48 h (1.9% ± 1.9% following exercise, but effects on soreness and flexed arm angle and CK were unclear. These data suggest that dietary supplementation with probiotic strains S. thermophilus FP4 and B. breve BR03 attenuates performance decrements and muscle tension in the days following muscle-damaging exercise.

  18. Increase of stress resistance in Lactococcus lactis via a novel food-grade vector expressing a shsp gene from Streptococcus thermophilus

    Directory of Open Access Journals (Sweden)

    Hongtao Tian

    2012-09-01

    Full Text Available The effects of the expression of a small heat shock protein (shsp gene from Streptococcus thermophilus on stress resistance in Lactococcus lactis under different environmental stresses were investigated in this study. pMG36e-shsp, an expression vector, was first constructed by inserting a shsp open reading frame (ORF cloned from S. thermophilus strain St-QC into pMG36e. Then, a food-grade expression vector, pMG-shsp, was generated by deleting the erythromycin resistance gene from pMG36e-shsp. The transformation rate of pMG-shsp was comparable to that of pMG36e-shsp when each of these two vectors was introduced into L. lactis. These results demonstrated that the shsp ORF could successfully used as a food-grade selection marker in both pMG-shsp and pMG36e-shsp. Furthermore, the growth characteristics were almost the same between L. lactis ML23 transformants harboring pMG36e or pMG-shsp. The survival rate of L. lactis ML23 expressing the shsp ORF were increased to 0.032%, 0.006%, 0.0027%, 0.03%, and 0.16% under the following environmental stresses: heat, acid, ethanol, bile salt and H2O2, respectively. These results indicated that the expression of the shsp gene in the food-grade vector pMG-shsp conferred resistance to environmental stresses without affecting the growth characteristics of L. lactis ML23.

  19. Use of microparticulated whey protein concentrate, exopolysaccharide-producing Streptococcus thermophilus, and adjunct cultures for making low-fat Italian Caciotta-type cheese.

    Science.gov (United States)

    Di Cagno, R; De Pasquale, I; De Angelis, M; Buchin, S; Rizzello, C G; Gobbetti, M

    2014-01-01

    Low-fat Caciotta-type cheeses were manufactured with partially skim milk (fat content of ~0.3%) alone (LFC); with the supplementation of 0.5% (wt/vol) microparticulated whey protein concentrate (MWPC) (LFC-MWPC); with MWPC and exopolysaccharides (EPS)-producing Streptococcus thermophilus ST446 (LFC-MWPC-EPS); and with MWPC, EPS-producing strain ST446, and Lactobacillus plantarum LP and Lactobacillus rhamnosus LRA as adjunct cultures (LFC-MWPC-EPS-A). The non-EPS-producing isogenic variant Streptococcus thermophilus ST042 was used for making full-fat Caciotta-type cheese (FFC), LFC, and LFC-MWPC. Cheeses were characterized based on compositional, microbiological, biochemical, texture, volatile components (purge and trap, and solid-phase microextraction coupled with gas chromatography-mass spectrometry), and sensory analyses. Compared with FFC and LFC (51.6 ± 0.7 to 53.0 ± 0.9%), the other cheese variants retained higher levels of moisture (60.5 ± 1.1 to 67.5 ± 0.5%). The MWPC mainly contributed to moisture retention. Overall, all LFC had approximately one-fourth (22.6 ± 0.8%) of the fat of FFC. Hardness of cheeses slightly varied over 7d of ripening. Microbial EPS positively affected cheese texture, and the texture of LFC without MWPC or microbial EPS was excessively firm. Free amino acids were at the highest levels in LFC treatments (2,705.8 ± 122 to 3,070.4 ± 123 mg/kg) due to the addition of MWPC and the peptidase activity of adjunct cultures. Aldehydes, alcohols, ketones, sulfur compounds, and short- to medium-chain carboxylic acids differentiated LFC variants and FFC. The sensory attributes pleasant to taste, intensity of flavor, overall acceptability, and pleasant to chew variously described LFC-MWPC-EPS and LFC-MWPC-EPS-A. Based on the technology options used, low-fat Caciotta-type cheese (especially ripened for 14 d) has promising features to be further exploited as a suitable alternative to the full-fat variant. Copyright © 2014 American Dairy

  20. The influence of fermentation condition on production and molecular mass of EPS produced by Streptococcus thermophilus 05-34 in milk-based medium.

    Science.gov (United States)

    Li, Dan; Li, Jiaxi; Zhao, Feng; Wang, Guohong; Qin, Qianqian; Hao, Yanling

    2016-04-15

    The yield of exopolysaccharide (EPS) produced by Streptococcus thermophilus 05-34 reached up to 250 mg/L under the optimal fermentation condition, which was 4.2-fold higher than that produced under the non-optimal fermentation condition. Structure analysis showed that EPS produced under the optimal fermentation condition was composed of galactose and glucose in a molar ratio of 1.0:0.8. This EPS was with a molecular mass of 4.7×10(5) Da, which was increased by 9 times compared with that in the non-optimal fermentation condition, while monosaccharide composition did not change. Furthermore, real-time quantitative PCR showed that the transcription level of epsC, which is responsible for chain-length determination, was up-regulated by 2.7-fold, suggesting that the increased molecular mass of EPS was resulted from improving polymerization degree of monosaccharide. These findings demonstrated that the optimized fermentation condition can improve EPS molecular mass, and may consequently modify the rheological properties of EPS. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Improved Helicobacter pylori Eradication Rate of Tailored Triple Therapy by Adding Lactobacillus delbrueckii and Streptococcus thermophilus in Northeast Region of Thailand: A Prospective Randomized Controlled Clinical Trial

    Directory of Open Access Journals (Sweden)

    Taweesak Tongtawee

    2015-01-01

    Full Text Available Background and Aim. To evaluate the effect of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus to Helicobacter pylori eradication in different periods of therapeutic protocol. Methods. Infected patients were randomized to one-week tailored triple therapy (esomeprazole 20 mg bid, clarithromycin 500 mg bid/metronidazole 400 mg tid if clarithromycin resistant, and amoxicillin 1000 mg bid with placebo (group 1, n=100; one week of pretreatment with probiotics (group 2, n=100; and one week of pretreatment with probiotic followed by one week of the same probiotics after treatment (group 3, n=100. Result. PP analysis involved 292 patients, 98 in group 1, 97 in group 2, and 97 in group 3. Successful eradication was observed in 229 patients; by PP analysis, the eradication rates were significantly higher (P<0.01, 95% CI; 0.71–0.97 in group 2 and group 3 than group 1. ITT analysis eradication rates were significantly higher in group 2 and group 3 than group 1 (P<0.01 95% CI; 0.72–0.87, and there is no significant difference between the three groups (P=0.32 in terms of adverse events. Conclusion. Adding probiotics before or before and after tailored treatment can improve Helicobacter pylori eradication rates. This trial is registered with Thai Clinical Trials Registry number: TCTR20141209001.

  2. Instrumental texture and sensory evaluation of fermented dairy beverages processed with reconstituted goat whey powder and a co-culture of Streptococcus thermophilus and Lactobacillus casei

    Directory of Open Access Journals (Sweden)

    Áurea Marcela de Souza Pereira

    2018-01-01

    Full Text Available The effects of Lactobacillus casei BGP93 used as adjunct culture on the physicochemical, textural and sensory characteristics of a dairy beverage processed with goat Coalho cheese whey powder and Streptococcus thermophilus TA-40 as starter (ST-LC beverage were investigated in comparison to a control product (ST beverage without L. casei. No significant differences were observed between the ST and ST-LC trials concerning the acidification pattern throughout the fermentation process (P>0.05. Post-acidification was also not observed for both trials since their pH values were maintained stable, without significant differences during 21 days at 4 ± 1 °C. This pH stability reinforced the maintenance of firmness, consistency, cohesiveness and viscosity index without significant differences between the sampling periods throughout the whole storage in both trials, and also that no significant difference was verified between the ST and ST-LC beverages in the sensory evaluation (P>0.05.

  3. Improved Growth of Lactobacillus bulgaricus and Streptococcus thermophilus as well as Increased Antioxidant Activity by Biotransforming Litchi Pericarp Polysaccharide with Aspergillus awamori

    Directory of Open Access Journals (Sweden)

    Sen Lin

    2013-01-01

    Full Text Available This study was conducted to increase the bioactivity of litchi pericarp polysaccharides (LPPs biotransformed by Aspergillus awamori. Compared to the non-A. awamori-fermented LPP, the growth effects of A. awamori-fermented LPP on Lactobacillus bulgaricus and Streptococcus thermophilus were four and two times higher after 3 days of fermentation, respectively. Increased 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity and DNA protection activity of litchi pericarp polysaccharides were also achieved after A. awamori fermentation. Moreover, the relative content of glucose and arabinose in LPP after fermentation decreased from 58.82% to 22.60% and from 18.82% to 10.09%, respectively, with a concomitant increase in the relative contents of galactose, rhamnose, xylose, and mannose. Furthermore, lower molecular weight polysaccharides were obtained after A. awamori fermentation. It can be concluded that A. awamori was effective in biotransforming LPP into a bioactive mixture with lower molecular weight polysaccharides and higher antioxidant activity and relative galactose content.

  4. Sulphonated modification of polysaccharides from Pleurotus eryngii and Streptococcus thermophilus ASCC 1275 and antioxidant activities investigation using CCD and Caco-2 cell line models.

    Science.gov (United States)

    Li, Siqian; Shah, Nagendra P

    2017-06-15

    Polysaccharides extracted from Pleurotus eryngii (PEPS) and Streptococcus thermophilus ASCC 1275 (EPS) were sulphonated and their composition determined. Antioxidant activities of crude and sulphonated polysaccharides (S.PEPS and S.EPS) were investigated using the ABTS radical scavenging test and CCD and Caco-2 cell models. Degrees of sulphonation for S.PEPS and S.EPS were 0.73 and 0.37, respectively. Results showed that S.PEPS and S.EPS had significantly higher scavenging capacities than PEPS and EPS in the ABTS radical scavenging test. Reactive oxygen species and malondialdehyde in H2O2 treated CCD 841 CoN (CCD) and Caco-2 cells were significantly inhibited by PEPS, EPS, S.PEPS and S.EPS compared to the control group. Additionally, S.PEPS and S.EPS significantly improved superoxide dismutase, catalase and glutathione peroxidase activities in H2O2 treated CCD and Caco-2 cells compared to PEPS, EPS and control groups. Results indicated that sulphonation was effective in improving antioxidant activities of both PEPS and EPS. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Novel optimal temperature profile for acidification process of Lactobacillus bulgaricus and Streptococcus thermophilus in yoghurt fermentation using artificial neural network and genetic algorithm.

    Science.gov (United States)

    Gueguim-Kana, E B; Oloke, J K; Lateef, A; Zebaze-Kana, M G

    2007-07-01

    The acidification behavior of Lactobacillus bulgaricus and Streptococcus thermophilus for yoghurt production was investigated along temperature profiles within the optimal window of 38-44 degrees C. For the optimal acidification temperature profile search, an optimization engine module built on a modular artificial neural network (ANN) and genetic algorithm (GA) was used. Fourteen batches of yoghurt fermentations were evaluated using different temperature profiles in order to train and validate the ANN sub-module. The ANN captured the nonlinear relationship between temperature profiles and acidification patterns on training data after 150 epochs. This served as an evaluation function for the GA. The acidification slope of the temperature profile was the performance index. The GA sub-module iteratively evolved better temperature profiles across generations using GA operations. The stopping criterion was met after 11 generations. The optimal profile showed an acidification slope of 0.06117 compared to an initial value of 0.0127 and at a set point sequence of 43, 38, 44, 43, and 39 degrees C. Laboratory evaluation of three replicates of the GA suggested optimum profile of 43, 38, 44, 43, and 39 degrees C gave an average slope of 0.04132. The optimization engine used (to be published elsewhere) could effectively search for optimal profiles of different physico-chemical parameters of fermentation processes.

  6. Comparative Analysis of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) of Streptococcus thermophilus St-I and its Bacteriophage-Insensitive Mutants (BIM) Derivatives.

    Science.gov (United States)

    Li, Wan; Bian, Xin; Evivie, Smith Etareri; Huo, Gui-Cheng

    2016-09-01

    The CRISPR-Cas (CRISPR together with CRISPR-associated proteins) modules are the adaptive immune system, acting as an adaptive and heritable immune system in bacteria and archaea. CRISPR-based immunity acts by integrating short virus sequences in the cell's CRISPR locus, allowing the cell to remember, recognize, and clear infections. In this study, the homology of CRISPRs sequence in BIMs (bacteriophage-insensitive mutants) of Streptococcus thermophilus St-I were analyzed. Secondary structures of the repeats and the PAMs (protospacer-associated motif) of each CRISPR locus were also predicted. Results showed that CRISPR1 has 27 repeat-spacer units, 5 of them had duplicates; CRISPR2 has one repeat-spacer unit; CRISPR3 has 28 repeat-spacer units. Only BIM1 had a new spacer acquisition in CRISPR3, while BIM2 and BIM3 had no new spacers' insertion, thus indicating that while most CRISPR1 were more active than CRISPR3, new spacer acquisition occurred just in CRSPR3 in some situations. These findings will help establish the foundation for the study of CRSPR-Cas systems in lactic acid bacteria.

  7. Nutritional Composition and Protein Profile of Goat Yogurt PE with Double Culture between Streptococcus thermophilus and Lactobacilus species

    Directory of Open Access Journals (Sweden)

    Ismi Kurnia Budiarti

    2013-08-01

    Full Text Available Aim: The aims of this study are to characterize the nutrient compositions and protein profiles of Etawah breed (PE goat yogurt fermented by double cultures . Material and Methods: To accomplish this, we used goat and bovine milk in five treatment groups: (1 fresh milk bovine, (2 goat,(3 milk fermented by L. acidophilus and S. thermophilus (LA + ST, (4 L. bulgaricus and S. thermophilus (LB+ ST,and (5 a comersial mixture. PE goat milk was fermented using 2.5% starting bacterial concentrations at 45oC with a pH ranging from 4.5 to 6.6. Nutrient compositions were measured by proximate analysis.SDS PAGE was conducted using 15% separating and 3% stacking gels. To measure the density of protein bands, we used QuantityOne software. Results: Our results indicated that LA+ST and LB+ST treatments had higher levels of lipids than the control treatment. Conversely, both strain combinations had lower levels of proteins than the control. Organoleptic testing suggests that many attributes (e.g., colour, taste, smell, texture and viscosity differ significantly from the control. Protein profiles revealed that while the LB + ST and commercial cultures contained proteins with a molecular weight of 36 kDa, the LA + ST cultures did not appear to possess this protein.Based on the molecular weight, we suggest that this protein is in the alpha casein group. Conclusion: The protein composition of fermented goat and bovine milk is similiar, but the absence of band with molecular weight 36 kDa from goat milk, LB+ST and mix comercial. [Cukurova Med J 2013; 38(4.000: 681-686

  8. Evaluation of the yield, molar mass of exopolysaccharides, and rheological properties of gels formed during fermentation of milk by Streptococcus thermophilus strains St-143 and ST-10255y.

    Science.gov (United States)

    Khanal, Som N; Lucey, John A

    2017-09-01

    The yield and chemical structures of exopolysaccharides (EPS) produced by many strains of Streptococcus thermophilus have been characterized. However, the kinetics (or production profile) for EPS during milk fermentation is not clear. In this study, we investigated whether any differences existed in the yield and molar mass of EPS when milk was fermented at the same acidification rate by 2 strains of S. thermophilus (St-143 and ST-10255y). The type of EPS produced by these 2 strains is different. Milk samples were analyzed for EPS concentration every 30 min during a fermentation period of 270 min (final pH 4.5) by using a modified quantification method, which was faster and validated for its recovery of added EPS. Rheological properties of milks during fermentation were also analyzed using small-strain dynamic oscillatory rheology. For the determination of molar mass, EPS extracts were isolated by ultrafiltration of whey obtained during fermentation of milk to pH values 5.2, 4.9, 4.7, and 4.5, and molar mass was analyzed using size-exclusion chromatography-multi-angle laser light scattering. During fermentation, both strains appeared to start producing significant amounts of EPS after about ∼150 min, which corresponded to pH ∼5.3, which was close to the point of gelation. During the remainder of the fermentation process (150-270 min), the EPS concentration from strains St-143 and ST-10255y significantly increased from 30 to 72 mg/L and from 26 to 56 mg/L, respectively. The quantity of EPS recovered by our modified method was estimated to represent ∼60% of the total EPS added to milk. The molar mass of EPS produced by both strains appeared to slightly decrease during fermentation. At pH 5.2, EPS from St-143 and ST-10255y had molar masses of 2.9 × 10(6) and 1.4 × 10(6) g/mol, respectively, which decreased to 1.6 × 10(6) and 0.8 × 10(6) g/mol, respectively, when the pH of milk was 4.5. Distinct differences were apparent in the rheological properties of gels

  9. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of a health claim related to a combination of Bifidobacterium logum LA 10, Lactobacillus helveticus LA 102, Lactococcus lactis LA 103 and Streptococcus thermophilus LA 104 and reducing

    DEFF Research Database (Denmark)

    Tetens, Inge

    substantiation of a health claim related to a combination of Bifidobacterium longum LA 101, Lactobacillus helveticus LA 102, Lactococcus lactis LA 103 and Streptococcus thermophilus LA 104 and reducing intestinal discomfort. The food that is the subject of the health claim is a combination of B. longum LA 101, L...

  10. EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2014. Scientific Opinion on the substantiation of a health claim related to a combination of Bifidobacterium longum LA 101, Lactobacillus helveticus LA 102, Lactococcus lactis LA 103 and Streptococcus thermophilus LA 104

    DEFF Research Database (Denmark)

    Tetens, Inge

    2014-01-01

    to a combination of Bifidobacterium longum LA 101, Lactobacillus helveticus LA 102, Lactococcus lactis LA 103 and Streptococcus thermophilus LA 104 and reducing intestinal discomfort. The food that is the subject of the health claim is a combination of four bacterial strains—B. longum LA 101, L. helveticus LA 102...

  11. EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2014. Scientific Opinion on the substantiation of a health claim related to a combination of Bifidobacterium longum LA 101, Lactobacillus helveticus LA 102, Lactococcus lactis LA 103 and Streptococcus thermophilus LA 104

    DEFF Research Database (Denmark)

    Tetens, Inge

    2014-01-01

    to a combination of Bifidobacterium longum LA 101, Lactobacillus helveticus LA 102, Lactococcus lactis LA 103 and Streptococcus thermophilus LA 104 and improvement of bowel function by increasing stool frequency. The food that is the subject of the health claim is a combination of four bacterial strains—B. longum...

  12. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of health claims related to a combination of Lactobacillus acidophilus BCCM/LMG P-18806, Lactobacillus delbrueckii BCCM/LMG P-18805 and Streptococcus thermophilus BCCM/LMG P-18807 and reduction

    DEFF Research Database (Denmark)

    Tetens, Inge

    of Lactobacillus acidophilus BCCM/LMG P-18806, Lactobacillus delbrueckii BCCM/LMG P-18805 and Streptococcus thermophilus BCCM/LMG P-18807 and reduction of gastro-intestinal discomfort, decreasing potentially pathogenic gastro-intestinal microorganisms, improved lactose digestion, and reduction in numbers...... of circulating CD34+ cells. The food constituent that is the subject of the health claim, a combination of L. acidophilus BCCM/LMG P-18806, L. delbrueckii BCCM/LMG P-18805 and S. thermophilus BCCM/LMG P-18807, is sufficiently characterised. The evidence provided did not establish that the proposed claimed effect...... substantiation of the above-mentioned claims. On the basis of the data provided, the Panel concludes that a cause and effect relationship has not been established between the consumption of a combination of L. acidophilus BCCM/LMG P-18806, L. delbrueckii BCCM/LMG P-18805 and S. thermophilus BCCM/LMG P-18807...

  13. The role of electrostatic interactions in the Streptococcus thermophilus adhesion on human erythrocytes in media with different 1:1 electrolyte concentration

    Directory of Open Access Journals (Sweden)

    О. І. Гордієнко

    2015-10-01

    Full Text Available The process of bacterial adhesion is usually discussed in terms of the two-stage sorption model. According to the model, at the first stage the bacteria fastly attaches to the surface by weak physical interactions, while at the second stage irreversible molecular and cellular adhesion process takes place. An important factor, influencing the adhesion processes, is physical-chemical characteristics of the medium, in particular, the presence of monovalent cations therein. The aim of this work is to assess the role of electrostatic component of the intercellular interactions at the first reversible stage of adhesion. Comparison of experimental data of adhesion of lactobacilli S. thermophilus on human erythrocytes and theoretical definition of the Debye radius and the erythrocytes surface potential in the experimental solutions showed that with decreasing ionic strength of the solution the change in the adhesion index in our experiments is fully in line with the theory DLVO predictions.

  14. Assessment of the capability of a gelling complex made of tara gum and the exopolysaccharides produced by the microorganism Streptococcus thermophilus ST10 to prospectively restore the gut physiological barrier: a pilot study.

    Science.gov (United States)

    Del Piano, Mario; Balzarini, Marco; Carmagnola, Stefania; Pagliarulo, Michela; Tari, Roberto; Nicola, Stefania; Deidda, Francesca; Pane, Marco

    2014-01-01

    Leaky gut, or intestinal permeability, is the phenomenon of the gut wall exhibiting increased absorbency. It is pretty well recognised that an altered or damaged bowel lining or gut wall may result from unbalanced diet, parasites, infection, or medications and that this allows substances such as toxins, microbes, undigested food, or waste to leak through. As a natural consequence, this prompts the body to initiate an immune reaction leading to potentially severe health conditions. Different strategies may be used to improve, at least temporarily, the physiological intestinal barrier. The use of specific beneficial microorganisms, such as lactobacilli and bifidobacteria, has been suggested as an innovative tool to counteract an improper level of intestinal permeability. The association of bacteria with specific gelling agents, such as gums, may represent an improvement since these molecules are able to form hydrophilic gels that distribute uniformly over the inner intestinal surface. This pilot study was undertaken to evaluate intestinal permeability in subjects treated with a gelling complex, an association of tara gum and the microorganism Streptococcus thermophilus ST10 (DSM 25246), which has a well-demonstrated in vitro ability to synthesise and secrete exopolysaccharides (EPSs). Twenty-five healthy subjects were enrolled in this human intervention, double-blind, placebo-controlled, pilot trial (age between 21 and 57 y, mean 37.7±11.2). Subjects were then randomised into 2 groups: group A (13 subjects) was given an active formulation containing 250 mg of tara gum and 1 billion viable cells of S. thermophilus ST10, whereas group B (12 subjects) was given a placebo formulation. All the subjects participating in the study were directed to take 1 dose per day for 30 consecutive days. The presence and concentration of exopolysaccharides (EPSs) in the faeces was determined at time 0 (d0), after 30 days of treatment (d30), and at the end of the 2-week follow-up period

  15. Comparative genomics of the dairy isolate Streptococcus macedonicus ACA-DC 198 against related members of the Streptococcus bovis/Streptococcus equinus complex.

    OpenAIRE

    Papadimitriou, Konstantinos; Anastasiou, Rania; Mavrogonatou, Eleni; Blom, Jochen; Papandreou, Nikos; Hamodrakas, Stavros; Ferreira, Stéphanie; Renault, Pierre; Supply, Philip; Pot, Bruno; Tsakalidou, Effie

    2014-01-01

    International audience; BACKGROUND: Within the genus Streptococcus, only Streptococcus thermophilus is used as a starter culture in food fermentations. Streptococcus macedonicus though, which belongs to the Streptococcus bovis/Streptococcus equinus complex (SBSEC), is also frequently isolated from fermented foods mainly of dairy origin. Members of the SBSEC have been implicated in human endocarditis and colon cancer. Here we compare the genome sequence of the dairy isolate S. macedonicus ACA-...

  16. Genome sequence of Streptococcus mutans bacteriophage M102

    OpenAIRE

    van der Ploeg, J R

    2017-01-01

    Bacteriophage M102 is a lytic phage specific for serotype c strains of Streptococcus mutans, a causative agent of dental caries. In this study, the complete genome sequence of M102 was determined. The genome is 31,147 bp in size and contains 41 ORFs. Most of the ORFs encoding putative phage structural proteins show similarity to those from bacteriophages from Streptococcus thermophilus. Bioinformatic analysis indicated that the M102 genome contains an unusual lysis cassette, which encodes a h...

  17. Inhibition of phage infection in capsule-producing Streptococcus ...

    African Journals Online (AJOL)

    SERVER

    2007-10-04

    Oct 4, 2007 ... Prazak A, Murano E, Mercado I, Acuff G (2002). Prevalence of Listeria monocytogenes during production and post harvest processing on cabbage. J. Food Prot. 65: 1728-1734. Quiberoni A, Stiefel J, Reinheimer J (2000). Characterization of phage receptors in Streptococcus thermophilus using purified cell ...

  18. Diversity, Activity, and Evolution of CRISPR Loci in Streptococcus thermophilus▿ †

    OpenAIRE

    Horvath, Philippe; Romero, Dennis A.; Coûté-Monvoisin, Anne-Claire; Richards, Melissa; Deveau, Hélène; Moineau, Sylvain; Boyaval, Patrick; Fremaux, Christophe; Barrangou, Rodolphe

    2007-01-01

    Clustered regularly interspaced short palindromic repeats (CRISPR) are hypervariable loci widely distributed in prokaryotes that provide acquired immunity against foreign genetic elements. Here, we characterize a novel Streptococcus thermophilus locus, CRISPR3, and experimentally demonstrate its ability to integrate novel spacers in response to bacteriophage. Also, we analyze CRISPR diversity and activity across three distinct CRISPR loci in several S. thermophilus strains. We show that both ...

  19. Streptococcus iniae and Streptococcus agalactiae

    Science.gov (United States)

    Streptococcus iniae and S. agalactiae are economically important Gram positive bacterial pathogens of cultured and wild fish with a worldwide distribution. Both bacteria are potential zoonotic pathogens and have been associated most often with infections in immunocompromised people. Streptococcus in...

  20. Diversity of human small intestinal Streptococcus and Veillonella populations.

    Science.gov (United States)

    van den Bogert, Bartholomeus; Erkus, Oylum; Boekhorst, Jos; de Goffau, Marcus; Smid, Eddy J; Zoetendal, Erwin G; Kleerebezem, Michiel

    2013-08-01

    Molecular and cultivation approaches were employed to study the phylogenetic richness and temporal dynamics of Streptococcus and Veillonella populations in the small intestine. Microbial profiling of human small intestinal samples collected from four ileostomy subjects at four time points displayed abundant populations of Streptococcus spp. most affiliated with S. salivarius, S. thermophilus, and S. parasanguinis, as well as Veillonella spp. affiliated with V. atypica, V. parvula, V. dispar, and V. rogosae. Relative abundances varied per subject and time of sampling. Streptococcus and Veillonella isolates were cultured using selective media from ileostoma effluent samples collected at two time points from a single subject. The richness of the Streptococcus and Veillonella isolates was assessed at species and strain level by 16S rRNA gene sequencing and genetic fingerprinting, respectively. A total of 160 Streptococcus and 37 Veillonella isolates were obtained. Genetic fingerprinting differentiated seven Streptococcus lineages from ileostoma effluent, illustrating the strain richness within this ecosystem. The Veillonella isolates were represented by a single phylotype. Our study demonstrated that the small intestinal Streptococcus populations displayed considerable changes over time at the genetic lineage level because only representative strains of a single Streptococcus lineage could be cultivated from ileostoma effluent at both time points. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  1. Effect of a BlpC-based quorum-sensing induction peptide on bacteriocin production in Streptococcus thermophiles

    Science.gov (United States)

    Bacteriocin synthesis in Streptococcus thermophilus is controlled by a complex blp locus. High levels of bacteriocin are produced only if the quorum-sensing regulatory mechanism is activated by the 30mer induction peptide (QSIP) which is embedded in the BlpC protein product of the blpC component. T...

  2. Transferable Denitrification Capability of Thermus thermophilus

    Science.gov (United States)

    Alvarez, Laura; Bricio, Carlos; Blesa, Alba; Hidalgo, Aurelio

    2014-01-01

    Laboratory-adapted strains of Thermus spp. have been shown to require oxygen for growth, including the model strains T. thermophilus HB27 and HB8. In contrast, many isolates of this species that have not been intensively grown under laboratory conditions keep the capability to grow anaerobically with one or more electron acceptors. The use of nitrogen oxides, especially nitrate, as electron acceptors is one of the most widespread capabilities among these facultative strains. In this process, nitrate is reduced to nitrite by a reductase (Nar) that also functions as electron transporter toward nitrite and nitric oxide reductases when nitrate is scarce, effectively replacing respiratory complex III. In many T. thermophilus denitrificant strains, most electrons for Nar are provided by a new class of NADH dehydrogenase (Nrc). The ability to reduce nitrite to NO and subsequently to N2O by the corresponding Nir and Nor reductases is also strain specific. The genes encoding the capabilities for nitrate (nar) and nitrite (nir and nor) respiration are easily transferred between T. thermophilus strains by natural competence or by a conjugation-like process and may be easily lost upon continuous growth under aerobic conditions. The reason for this instability is apparently related to the fact that these metabolic capabilities are encoded in gene cluster islands, which are delimited by insertion sequences and integrated within highly variable regions of easily transferable extrachromosomal elements. Together with the chromosomal genes, these plasmid-associated genetic islands constitute the extended pangenome of T. thermophilus that provides this species with an enhanced capability to adapt to changing environments. PMID:24141123

  3. Comparative genomics of the dairy isolate Streptococcus macedonicus ACA-DC 198 against related members of the Streptococcus bovis/Streptococcus equinus complex.

    Science.gov (United States)

    Papadimitriou, Konstantinos; Anastasiou, Rania; Mavrogonatou, Eleni; Blom, Jochen; Papandreou, Nikos C; Hamodrakas, Stavros J; Ferreira, Stéphanie; Renault, Pierre; Supply, Philip; Pot, Bruno; Tsakalidou, Effie

    2014-04-08

    Within the genus Streptococcus, only Streptococcus thermophilus is used as a starter culture in food fermentations. Streptococcus macedonicus though, which belongs to the Streptococcus bovis/Streptococcus equinus complex (SBSEC), is also frequently isolated from fermented foods mainly of dairy origin. Members of the SBSEC have been implicated in human endocarditis and colon cancer. Here we compare the genome sequence of the dairy isolate S. macedonicus ACA-DC 198 to the other SBSEC genomes in order to assess in silico its potential adaptation to milk and its pathogenicity status. Despite the fact that the SBSEC species were found tightly related based on whole genome phylogeny of streptococci, two distinct patterns of evolution were identified among them. Streptococcus macedonicus, Streptococcus infantarius CJ18 and Streptococcus pasteurianus ATCC 43144 seem to have undergone reductive evolution resulting in significantly diminished genome sizes and increased percentages of potential pseudogenes when compared to Streptococcus gallolyticus subsp. gallolyticus. In addition, the three species seem to have lost genes for catabolizing complex plant carbohydrates and for detoxifying toxic substances previously linked to the ability of S. gallolyticus to survive in the rumen. Analysis of the S. macedonicus genome revealed features that could support adaptation to milk, including an extra gene cluster for lactose and galactose metabolism, a proteolytic system for casein hydrolysis, auxotrophy for several vitamins, an increased ability to resist bacteriophages and horizontal gene transfer events with the dairy Lactococcus lactis and S. thermophilus as potential donors. In addition, S. macedonicus lacks several pathogenicity-related genes found in S. gallolyticus. For example, S. macedonicus has retained only one (i.e. the pil3) of the three pilus gene clusters which may mediate the binding of S. gallolyticus to the extracellular matrix. Unexpectedly, similar findings were

  4. Streptococcus suis

    DEFF Research Database (Denmark)

    Poggenborg, René; Gaïni, Shahin; Kjaeldgaard, Poul

    2008-01-01

    Meningitis and spondylodiscitis caused by Streptococcus suis is a rare disease which is contracted by occupational exposure to pigs. We report a 54-y-old pig-farm worker with S. suis meningitis and septicaemia complicated with thoracal and lumbar spine spondylodiscitis. The S. suis strain involved...

  5. Thermus thermophilus genome analysis: benefits and implications

    Directory of Open Access Journals (Sweden)

    Lioliou Efthimia E

    2004-05-01

    Full Text Available Abstract The genome sequence analysis of Thermus thermophilus HB27, a microorganism with high biotechnological potential, has recently been published. In that report, the chromosomal and the megaplasmid sequence were compared to those of other organisms and discussed on the basis of their physiological and metabolic features. Out of the 2,218 putative genes identified through the large genome sequencing project, a significant number has potential interest for biotechnology. The present communication will discuss the accumulating information on molecules participating in fundamental biological processes or having potential biotechnological importance.

  6. Streptococcus agalactiae

    Science.gov (United States)

    Al-Otaibi, Humoud M; Talea, Mohammed; Kirat, Omar; Stone, Donald U; May, William N; Kozak, Igor

    2016-01-01

    A 25-year-old Syrian male with a previous episode of Stevens-Johnson syndrome with bilateral corneal cicatrization previously underwent surgery for Type 1 Boston Keratoprosthesis (K-Pro). Sixteen months after the K-Pro surgery, the patient presented with decreased vision to hand motion and microbial keratitis of the graft around the K-Pro with purulent discharge. Corneal scrapings were nonrevealing. B-scan in 3 days showed increased debris in the vitreous cavity and thickened retinochoroidal layer. Intravitreal tap and injections of vancomycin and ceftazidime were performed. The vitreous culture revealed β-hemolytic Streptococcus agalactiae ; fungal cultures were negative. Repeat B-scan 3 days later demonstrated decreased vitreous opacity, and the patient felt more comfortable and was without pain. His visual acuity improved to 20/70, ocular findings have been stable for 9 months, and the patient continues to be monitored.

  7. Group B streptococcus - pregnancy

    Science.gov (United States)

    ... 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 ...

  8. Bioactive exopolysaccharides from a S. thermophilus strain: Screening, purification and characterization.

    Science.gov (United States)

    Ren, Wei; Xia, Yongjun; Wang, Guangqiang; Zhang, Hui; Zhu, Song; Ai, Lianzhong

    2016-05-01

    A lactic acid bacteria strain AR333 with high-production of exopolysaccharides (EPS) was screened out from 350 bacteria strains isolated from naturally fermented dairy products. It was identified as Streptococcus thermophilus by morphological observation, physiological and biochemical characteristics, and 16S rDNA sequence determination. The EPS from AR333 were purified through DEAE-Sepharose Fast Flow and Sepharose CL-6B, and the purified fraction was designated as EPS333. In vitro test showed that EPS333 could stimulate macrophage RAW 264.7 to release NO significantly (p<0.05). The further work tried to elucidate the structural features of EPS333 via FT-IR spectrum, high-performance anion exchange chromatography (HPAEC) and high-performance size exclusion chromatography (HPSEC). The results showed that EPS333 was a pure neutral polysaccharide with monosaccharide composition of galactose and glucose in a molar ratio of 6:5. A certain amount of acetyl groups might exist in EPS333 according to the FT-IR spectrum. The molecular weight (Mw) was estimated to be 332 kDa. Current study suggested that the lactic bacteria strain AR333 could be a potential source of immunoregulatory polysaccharide. Copyright © 2016. Published by Elsevier B.V.

  9. 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 ...

  10. Phytotherapy for Streptococcus pyogenes

    National Research Council Canada - National Science Library

    Somayeh Delfani; Reza Mohammadrezaei-Khorramabadi; Saber Abbaszadeh; Nasrollah Naghdi; Somayeh Shahsavari

    2017-01-01

    .... To achieve this purpose, bacterium, Streptococcus pyogenes, and medicinal plants were used as search terms to retrieve relevant publications from the Institute for Scientific Information of Web...

  11. Atomic force microscopic corroboration of bond ageing for adhesion of Streptococcus thermophilus to solid substrata

    NARCIS (Netherlands)

    Vadillo-Rodriguez, V.; Busscher, H.J.; Norde, W.; Vries, de J.

    2004-01-01

    Initial bacterial adhesion is considered to be reversible, but over time the adhesive bond between a bacterium and a substratum surface may strengthen, turning the process into an irreversible state. Microbial desorption has been studied in situ in controlled flow devices as a function of the

  12. Atomic force microscopic corroboration of bond aging for adhesion of Streptococcus thermophilus to solid substrata

    NARCIS (Netherlands)

    Vadillo-Rodrı́guez, Virginia; Busscher, Hendrik; Norde, Willem; de Vries, Jacob; van der Mei, Henny C

    2004-01-01

    Initial bacterial adhesion is considered to be reversible, but over time the adhesive bond between a bacterium and a substratum surface may strengthen, turning the process into an irreversible state. Microbial desorption has been studied in situ in controlled flow devices as a function of the

  13. A novel consortium of Lactobacillus rhamnosus and Streptococcus thermophilus for increased access to functional fermented foods

    NARCIS (Netherlands)

    Kort, Remco; Westerik, Nieke; Mariela Serrano, L.; Douillard, François P.; Gottstein, Willi; Mukisa, Ivan M.; Tuijn, Coosje J.; Basten, Lisa; Hafkamp, Bert; Meijer, Wilco C.; Teusink, Bas; Vos, de Willem; Reid, Gregor; Sybesma, Wilbert

    2015-01-01

    Background: The lactic acid bacterium Lactobacillus rhamnosus GG is the most studied probiotic bacterium with proven health benefits upon oral intake, including the alleviation of diarrhea. The mission of the Yoba for Life foundation is to provide impoverished communities in Africa increased

  14. A novel consortium of Lactobacillus rhamnosus and Streptococcus thermophilus for increased access to functional fermented foods

    NARCIS (Netherlands)

    Kort, R.; Westerik, N.; Mariela Serrano, L.; Douillard, F.P.; Gottstein, W.; Mukisa, I.M.; Tuijn, C.J.; Basten, L.; Hafkamp, B.; Meijer, W.C.; Teusink, B.; Vos, W.M.; Reid, G.; Sybesma, W.

    2015-01-01

    Background: The lactic acid bacterium Lactobacillus rhamnosus GG is the most studied probiotic bacterium with proven health benefits upon oral intake, including the alleviation of diarrhea. The mission of the Yoba for Life foundation is to provide impoverished communities in Africa increased access

  15. Genome Signature Difference between Deinococcus radiodurans and Thermus thermophilus

    Directory of Open Access Journals (Sweden)

    Hiromi Nishida

    2012-01-01

    Full Text Available The extremely radioresistant bacteria of the genus Deinococcus and the extremely thermophilic bacteria of the genus Thermus belong to a common taxonomic group. Considering the distinct living environments of Deinococcus and Thermus, different genes would have been acquired through horizontal gene transfer after their divergence from a common ancestor. Their guanine-cytosine (GC contents are similar; however, we hypothesized that their genomic signatures would be different. Our findings indicated that the genomes of Deinococcus radiodurans and Thermus thermophilus have different tetranucleotide frequencies. This analysis showed that the genome signature of D. radiodurans is most similar to that of Pseudomonas aeruginosa, whereas the genome signature of T. thermophilus is most similar to that of Thermanaerovibrio acidaminovorans. This difference in genome signatures may be related to the different evolutionary backgrounds of the 2 genera after their divergence from a common ancestor.

  16. Production of Recombinant α-Galactosidases in Thermus thermophilus

    Science.gov (United States)

    Fridjonsson, Olafur; Mattes, Ralf

    2001-01-01

    A Thermus thermophilus selector strain for production of thermostable and thermoactive α-galactosidase was constructed. For this purpose, the native α-galactosidase gene (agaT) of T. thermophilus TH125 was inactivated to prevent background activity. In our first attempt, insertional mutagenesis of agaT by using a cassette carrying a kanamycin resistance gene led to bacterial inability to utilize melibiose (α-galactoside) and galactose as sole carbohydrate sources due to a polar effect of the insertional inactivation. A Gal+ phenotype was assumed to be essential for growth on melibiose. In a Gal− background, accumulation of galactose or its metabolite derivatives produced from melibiose hydrolysis could interfere with the growth of the host strain harboring recombinant α-galactosidase. Moreover, the AgaT− strain had to be Kms for establishment of the plasmids containing α-galactosidase genes and the kanamycin resistance marker. Therefore, a suitable selector strain (AgaT− Gal+ Kms) was generated by applying integration mutagenesis in combination with phenotypic selection. To produce heterologous α-galactosidase in T. thermophilus, the isogenes agaA and agaB of Bacillus stearothermophilus KVE36 were cloned into an Escherichia coli-Thermus shuttle vector. The region containing the E. coli plasmid sequence (pUC-derived vector) was deleted before transformation of T. thermophilus with the recombinant plasmids. As a result, transformation efficiency and plasmid stability were improved. However, growth on minimal agar medium containing melibiose was achieved only following random selection of the clones carrying a plasmid-based mutation that had promoted a higher copy number and greater stability of the plasmid. PMID:11526023

  17. Thermus thermophilus Strains Active in Purine Nucleoside Synthesis

    Directory of Open Access Journals (Sweden)

    Marcos Almendros

    2009-03-01

    Full Text Available Several strains of Thermus thermophilus were tested in order to detect purine nucleoside synthase activity using pyrimidine nucleosides as the sugar-donor and adenine or hypoxanthine as bases. High productivity values (t =1 hr were obtained while completely avoiding adenosine-deaminase degradation of the products. N-2-deoxy-ribosyltransferase activity is described for the first time in hyperthermophilic bacteria.

  18. Comparative genome analysis of Streptococcus infantarius subsp. infantarius CJ18, an African fermented camel milk isolate with adaptations to dairy environment

    Science.gov (United States)

    2013-01-01

    Background Streptococcus infantarius subsp. infantarius (Sii) belongs to the Streptococcus bovis/Streptococcus equinus complex associated with several human and animal infections. Sii is a predominant bacterium in spontaneously fermented milk products in Africa. The genome sequence of Sii strain CJ18 was compared with that of other Streptococcus species to identify dairy adaptations including genome decay such as in Streptococcus thermophilus, traits for its competitiveness in spontaneous milk fermentation and to assess potential health risks for consumers. Results The genome of Sii CJ18 harbors several unique regions in comparison to Sii ATCC BAA-102T, among others an enlarged exo- and capsular polysaccharide operon; Streptococcus thermophilus-associated genes; a region containing metabolic and hypothetical genes mostly unique to CJ18 and the dairy isolate Streptococcus gallolyticus subsp. macedonicus; and a second oligopeptide transport operon. Dairy adaptations in CJ18 are reflected by a high percentage of pseudogenes (4.9%) representing genome decay which includes the inactivation of the lactose phosphotransferase system (lacIIABC) by multiple transposases integration. The presence of lacS and lacZ genes is the major dairy adaptation affecting lactose metabolism pathways also due to the disruption of lacIIABC. We constructed mutant strains of lacS, lacZ and lacIIABC and analyzed the resulting strains of CJ18 to confirm the redirection of lactose metabolism via LacS and LacZ. Natural competence genes are conserved in both Sii strains, but CJ18 contains a lower number of CRISPR spacers which indicates a reduced defense capability against alien DNA. No classical streptococcal virulence factors were detected in both Sii strains apart from those involved in adhesion which should be considered niche factors. Sii-specific virulence factors are not described. Several Sii-specific regions encoding uncharacterized proteins provide new leads for virulence analyses and

  19. Comparative genome analysis of Streptococcus infantarius subsp. infantarius CJ18, an African fermented camel milk isolate with adaptations to dairy environment.

    Science.gov (United States)

    Jans, Christoph; Follador, Rainer; Hochstrasser, Mira; Lacroix, Christophe; Meile, Leo; Stevens, Marc J A

    2013-03-22

    Streptococcus infantarius subsp. infantarius (Sii) belongs to the Streptococcus bovis/Streptococcus equinus complex associated with several human and animal infections. Sii is a predominant bacterium in spontaneously fermented milk products in Africa. The genome sequence of Sii strain CJ18 was compared with that of other Streptococcus species to identify dairy adaptations including genome decay such as in Streptococcus thermophilus, traits for its competitiveness in spontaneous milk fermentation and to assess potential health risks for consumers. The genome of Sii CJ18 harbors several unique regions in comparison to Sii ATCC BAA-102T, among others an enlarged exo- and capsular polysaccharide operon; Streptococcus thermophilus-associated genes; a region containing metabolic and hypothetical genes mostly unique to CJ18 and the dairy isolate Streptococcus gallolyticus subsp. macedonicus; and a second oligopeptide transport operon. Dairy adaptations in CJ18 are reflected by a high percentage of pseudogenes (4.9%) representing genome decay which includes the inactivation of the lactose phosphotransferase system (lacIIABC) by multiple transposases integration. The presence of lacS and lacZ genes is the major dairy adaptation affecting lactose metabolism pathways also due to the disruption of lacIIABC.We constructed mutant strains of lacS, lacZ and lacIIABC and analyzed the resulting strains of CJ18 to confirm the redirection of lactose metabolism via LacS and LacZ.Natural competence genes are conserved in both Sii strains, but CJ18 contains a lower number of CRISPR spacers which indicates a reduced defense capability against alien DNA. No classical streptococcal virulence factors were detected in both Sii strains apart from those involved in adhesion which should be considered niche factors. Sii-specific virulence factors are not described. Several Sii-specific regions encoding uncharacterized proteins provide new leads for virulence analyses and investigation of the

  20. Streptococcus anginosus ("Streptococcus milleri"): the unrecognized pathogen.

    Science.gov (United States)

    Ruoff, K L

    1988-01-01

    "Streptococcus milleri" is an unofficial name that has been applied to a group of streptococci which, although basically similar, show various hemolytic, serological, and physiological characteristics. The species name Streptococcus anginosus has recently been recognized as the approved name for these organisms. Streptococci known as "S. milleri" have been implicated as etiologic agents in a variety of serious purulent infections, but because of their heterogeneous characteristics, these organisms may be unrecognized or misidentified by clinical laboratorians. This review describes the bacteriological aspects of organisms known as "S. milleri," their clinical significance, and the problems encountered with their identification in the clinical laboratory. PMID:3060239

  1. Septicemia with Streptococcus pseudopneumoniae

    DEFF Research Database (Denmark)

    Fuursted, Kurt; Littauer, Pia Jeanette; Greve, Thomas

    2016-01-01

    Streptococcus pseudopneumoniae was described in 2004 as a new human pathogen, acknowledged in a range of clinical infections typically associated to the respiratory tract. This report demonstrates that S. pseudopneumoniae has the potential to cause invasive infection. In blood cultures from three...... patients, growth of an atypical Streptococcus pneumoniae (non-capsular, non-serotypeable, optochin susceptible under ambient atmosphere and bile-intermediately soluble) was recovered. All three patients had a history of a haematological disease (myelodysplastic syndrome and multiple myeloma...

  2. Gene Regulation in Streptococcus pneumoniae: interplay between nutrition and virulence

    NARCIS (Netherlands)

    W.T. Hendriksen (Wouter)

    2010-01-01

    textabstractStreptococcus pneumoniae (the pneumococcus) is a Gram-positive bacterium, which belongs to the species of streptococci. Other pathogenic bacteria belonging to this class include Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus suis, Streptococcus uberis, Streptococcus

  3. Pengaruh Variasi Konsentrasi Inulin pada Proses Fermentasi oleh L. acidophilus, L. bulgaricus dan S. thermophillus - (The Inulin Variation Concentration Effect in Fermentation Using L. acidophilus, L. bulgaricus and S. thermophilus

    Directory of Open Access Journals (Sweden)

    Raden Haryo Bimo Setiarto

    2017-06-01

    Full Text Available Prebiotics are food components that can not enzymatically digested, thus it fermented by probiotic bacteria. Inulin is a prebiotic source that widely used in processed food products such as fermented milk. This study aimed to know the variation concentrations effect of prebiotic inulin on the growth of lactic acid bacteria starter yogurt (Lactobacillus acidophillus, Lactobacillus bulgaricus, Streptococcus thermophillus. The growth of those lactic acid bacteries was determined based on OD (Optical Density, Total Plate Count (TPC, total lactic acid content and pH. Inulin concentration of 0.5% (w/v increased the growth of those three bacteries. Reductioned of pH value during inulin fermentation indicated the growth of bacteria that produced lactic acid. L.bulgaricus and S.thermophilus growth rate were more sensitive than L.acidophilus in addition of prebiotic inulin concentration. The growth of those bacteries in MRSB medium supplemented inulin decreased pH around 7.00 into below 5.00 due to organic acids formation.Keywords: Fermentation, Inulin, L.acidophilus, L.bulgaricus, S.thermophilusABSTRAKPrebiotik adalah komponen bahan pangan yang tidak dapat dicerna oleh saluran pencernaan secara enzimatis sehingga akan difermentasi oleh bakteri probiotik di usus besar. Inulin merupakan salah satu sumber prebiotik yang banyak dimanfaatkan dalam produk pangan olahan seperti susu fermentasi. Pemberian inulin pada kadar tertentu perlu diketahui untuk mengetahui jumlah optimal yang diperlukan untuk menjaga kesehatan. Penelitian ini bertujuan untuk mengetahui pengaruh variasi konsentrasi prebiotik inulin terhadap pertumbuhan bakteri asam laktat starter yogurt (Lactobacillus acidophillus, Lactobacillus bulgaricus dan Streptococcus thermophillus. Pengamatan pertumbuhan L. acidophilus, L. bulgaricus dan S. thermophillus dilakukan dengan beberapa cara antara lain perhitungan total sel dengan menggunakan prinsip turbidimetrik OD (Optical Density,  jumlah total

  4. Controlled Human Infection for Vaccination Against Streptococcus Pyogenes

    Science.gov (United States)

    2018-01-21

    Streptococcus Pyogenes Pharyngitis; Streptococcus Pharyngitis; Strep Throat; Streptococcus Pyogenes Infection; Group A Streptococcus: B Hemolytic Pharyngitis; Group A Streptococcal Infection; Gram-Positive Bacterial Infections; Bacterial Infections

  5. Exploring internal features of 16S rRNA gene for identification of clinically relevant species of the genus Streptococcus

    Science.gov (United States)

    2011-01-01

    Background Streptococcus is an economically important genus as a number of species belonging to this genus are human and animal pathogens. The genus has been divided into different groups based on 16S rRNA gene sequence similarity. The variability observed among the members of these groups is low and it is difficult to distinguish them. The present study was taken up to explore 16S rRNA gene sequence to develop methods that can be used for preliminary identification and can supplement the existing methods for identification of clinically-relevant isolates of the genus Streptococcus. Methods 16S rRNA gene sequences belonging to the isolates of S. dysgalactiae, S. equi, S. pyogenes, S. agalactiae, S. bovis, S. gallolyticus, S. mutans, S. sobrinus, S. mitis, S. pneumoniae, S. thermophilus and S. anginosus were analyzed with the purpose to define genetic variability within each species to generate a phylogenetic framework, to identify species-specific signatures and in-silico restriction enzyme analysis. Results The framework based analysis was used to segregate Streptococcus spp. previously identified upto genus level. This segregation was validated using species-specific signatures and in-silico restriction enzyme analysis. 43 uncharacterized Streptococcus spp. could be identified using this approach. Conclusions The markers generated exploring 16S rRNA gene sequences provided useful tool that can be further used for identification of different species of the genus Streptococcus. PMID:21702978

  6. Exploring internal features of 16S rRNA gene for identification of clinically relevant species of the genus Streptococcus.

    Science.gov (United States)

    Lal, Devi; Verma, Mansi; Lal, Rup

    2011-06-25

    Streptococcus is an economically important genus as a number of species belonging to this genus are human and animal pathogens. The genus has been divided into different groups based on 16S rRNA gene sequence similarity. The variability observed among the members of these groups is low and it is difficult to distinguish them. The present study was taken up to explore 16S rRNA gene sequence to develop methods that can be used for preliminary identification and can supplement the existing methods for identification of clinically-relevant isolates of the genus Streptococcus. 16S rRNA gene sequences belonging to the isolates of S. dysgalactiae, S. equi, S. pyogenes, S. agalactiae, S. bovis, S. gallolyticus, S. mutans, S. sobrinus, S. mitis, S. pneumoniae, S. thermophilus and S. anginosus were analyzed with the purpose to define genetic variability within each species to generate a phylogenetic framework, to identify species-specific signatures and in-silico restriction enzyme analysis. The framework based analysis was used to segregate Streptococcus spp. previously identified upto genus level. This segregation was validated using species-specific signatures and in-silico restriction enzyme analysis. 43 uncharacterized Streptococcus spp. could be identified using this approach. The markers generated exploring 16S rRNA gene sequences provided useful tool that can be further used for identification of different species of the genus Streptococcus.

  7. RAPID ARSENITE OXIDATION BY THERMUS AQUATICUS AND THERMUS THERMOPHILUS: FIELD AND LABORATORY INVESTIGATIONS. (R826189)

    Science.gov (United States)

    Thermus aquaticus and Thermus thermophilus, common inhabitants of terrestrial hot springs and thermally polluted domestic and industrial waters, have been found to rapidly oxidize arsenite to arsenate. Field investigations at a hot spring in Yellowstone National Park revealed ...

  8. Structure of the Hydrophilic Domain of Respiratory Complex I from Thermus thermophilus

    National Research Council Canada - National Science Library

    Leonid A. Sazanov; Philip Hinchliffe

    2006-01-01

    ...) of complex I from Thermus thermophilus has been solved at 3.3 angstrom resolution. This subcomplex consists of eight subunits and contains all the redox centers of the enzyme, including nine iron-sulfur clusters...

  9. Emended descriptions and recognition of Streptococcus constellatus, Streptococcus intermedius, and Streptococcus anginosus as distinct species.

    Science.gov (United States)

    Whiley, R A; Beighton, D

    1991-01-01

    Strains currently classified as Streptococcus anginosus include strains previously identified as Streptococcus constellatus (Prevot 1924) Holdeman and Moore 1974, Streptococcus intermedius (Prevot 1925), and "Streptococcus milleri" (Guthof 1956) because these specific epithets were argued to be later synonyms of Streptococcus anginosus (Andrewes and Horder 1906) Smith and Sherman 1938 by Coykendall et al. (Int. J. Syst. Bacteriol. 37:222-228, 1987). However, recent data from DNA-DNA hybridization experiments, whole-cell-derived polypeptide patterns determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and data from phenotypic testing have demonstrated that Streptococcus anginosus strains represent three readily identifiable taxa to which the previously assigned type strains of Streptococcus constellatus (strain NCDO 2226 [= ATCC 27823], Streptococcus intermedius (strain NCDO 2227 [= ATCC 27335], and Streptococcus anginosus (strain NCTC 10713 [= ATCC 33397] have been shown to belong. Therefore, we propose recognition of Streptococcus constellatus (emend.) (type strain NCDO 2226 [= ATCC 27823]), Streptococcus intermedius (emend.) (type strain NCDO 2227 [= ATCC 27335]), and Streptococcus anginosus (emend.) (type strain NCTC 10713 [= ATCC 33397]) as distinct species and propose an emended description of each of these taxa.

  10. Short communication: Viability of culture organisms in honey-enriched acidophilus-bifidus-thermophilus (ABT)-type fermented camel milk.

    Science.gov (United States)

    Varga, L; Süle, J; Nagy, P

    2014-11-01

    The aim of this research was to monitor the survival during refrigerated storage of Lactobacillus acidophilus LA-5 (A), Bifidobacterium animalis ssp. lactis BB-12 (B), and Streptococcus thermophilus CHCC 742/2130 (T) in cultured dairy foods made from camel and, for comparison, cow milks supplemented with black locust (Robinia pseudoacacia L.) honey and fermented by an acidophilus-bifidus-thermophilus (ABT)-type culture. Two liters of dromedary camel milk and 2 L of cow milk were heated to 90 °C and held for 10 min, then cooled to 40 °C. One half of both types of milk was fortified with black locust honey at the rate of 5.0% (wt/vol), whereas the other half was devoid of honey and served as a control. The camel and cow milks with and without honey were subsequently inoculated with ABT-5 culture and were fermented at 37 °C until a pH value of 4.6 was reached. Thereafter, the probiotic fermented milks were cooled to 15 °C in ice water and were each separated into 18 fractions that were transferred in sterile, tightly capped centrifuge tubes. After 24 h of cooling at 8 °C (d 0), the samples were stored at refrigeration temperature (4 °C). Three tubes of all 4 products (i.e., fermented camel and cow milks with and without honey) were taken at each sampling time (i.e., following 0, 7, 14, 21, 28, and 35 d of storage), and the counts of characteristic microorganisms and those of certain spoilage microbes (yeasts, molds, coliforms, Escherichia coli) were enumerated. The entire experimental program was repeated twice. The results showed that addition of black locust honey at 5% to heat-treated camel and cow milks did not influence the growth and survival of starter streptococci during production and subsequent refrigerated storage of fermented ABT milks. In contrast, honey improved retention of viability of B. animalis ssp. lactis BB-12 in the camel milk-based product during storage at 4 °C up to 5 wk. No spoilage organisms were detected in any of the samples tested

  11. Phenotypic differentiation of Streptococcus intermedius, Streptococcus constellatus, and Streptococcus anginosus strains within the "Streptococcus milleri group".

    Science.gov (United States)

    Whiley, R A; Fraser, H; Hardie, J M; Beighton, D

    1990-01-01

    A biochemical scheme was developed by which strains of Streptococcus constellatus, Streptococcus intermedius, and Streptococcus anginosus can reliably be distinguished from within the "Streptococcus milleri group." Strains identified as S. intermedius were differentiated by the ability to produce detectable levels of alpha-glucosidase, beta-galactosidase, beta-D-fucosidase, beta-N-acetylgalactosaminidase, beta-N-acetylglucosaminidase, and sialidase with 4-methylumbelliferyl-linked fluorogenic substrates in microdilution trays after 3 h of incubation at 37 degrees C, together with the production of hyaluronidase. Strains of S. constellatus and S. anginosus were differentiated by the production of alpha-glucosidase and hyaluronidase by the former and the production of beta-glucosidase by the latter. The majority of strains of the S. milleri group obtained from dental plaque were identified as S. intermedius, as were most strains isolated from abscesses of the brain and liver. Strains of S. constellatus and S. anginosus were from a wider variety of infections, both oral and nonoral, than were strains of S. intermedius, with the majority of strains from urogenital infections being identified as S. anginosus. PMID:2380375

  12. Bacteremia with Streptococcus pneumoniae

    DEFF Research Database (Denmark)

    Christensen, J S; Jensen, T G; Kolmos, H J

    2012-01-01

    We conducted a hospital-based cohort study among adult patients with first-time Streptococcus pneumoniae bacteremia (SPB) from 2000 through 2008. Patients were identified in a population-based bacteremia database and followed up for mortality through the Danish Civil Registration System (CRS...

  13. Streptococcus pasteurianus septicemia.

    Science.gov (United States)

    Alex, D; Garvin, D F; Peters, S M

    2013-01-01

    Streptococcus pasteurianus is part of the normal flora of the intestine. It has also been isolated from various infection sites. However, to date it has not been reported as a cause of fulminant septicemia and death. We report the post-mortem findings in a splenectomized hemophiliac patient with cirrhosis and concurrent human immunodeficiency virus (HIV), hepatitis B and hepatitis C infections.

  14. Streptococcus pasteurianus septicemia

    OpenAIRE

    D Alex; D F Garvin; S M Peters

    2013-01-01

    Streptococcus pasteurianus is part of the normal flora of the intestine. It has also been isolated from various infection sites. However, to date it has not been reported as a cause of fulminant septicemia and death. We report the post-mortem findings in a splenectomized hemophiliac patient with cirrhosis and concurrent human immunodeficiency virus (HIV), hepatitis B and hepatitis C infections.

  15. Effects of Argonaute on Gene Expression in Thermus thermophilus.

    Directory of Open Access Journals (Sweden)

    Daan C Swarts

    Full Text Available Eukaryotic Argonaute proteins mediate RNA-guided RNA interference, allowing both regulation of host gene expression and defense against invading mobile genetic elements. Recently, it has become evident that prokaryotic Argonaute homologs mediate DNA-guided DNA interference, and play a role in host defense. Argonaute of the bacterium Thermus thermophilus (TtAgo targets invading plasmid DNA during and after transformation. Using small interfering DNA guides, TtAgo can cleave single and double stranded DNAs. Although TtAgo additionally has been demonstrated to cleave RNA targets complementary to its DNA guide in vitro, RNA targeting by TtAgo has not been demonstrated in vivo.To investigate if TtAgo also has the potential to control RNA levels, we analyzed RNA-seq data derived from cultures of four T. thermophilus strain HB27 variants: wild type, TtAgo knockout (Δago, and either strain transformed with a plasmid. Additionally we determined the effect of TtAgo on expression of plasmid-encoded RNA and plasmid DNA levels.In the absence of exogenous DNA (plasmid, TtAgo presence or absence had no effect on gene expression levels. When plasmid DNA is present, TtAgo reduces plasmid DNA levels 4-fold, and a corresponding reduction of plasmid gene transcript levels was observed. We therefore conclude that TtAgo interferes with plasmid DNA, but not with plasmid-encoded RNA. Interestingly, TtAgo presence stimulates expression of specific endogenous genes, but only when exogenous plasmid DNA was present. Specifically, the presence of TtAgo directly or indirectly stimulates expression of CRISPR loci and associated genes, some of which are involved in CRISPR adaptation. This suggests that TtAgo-mediated interference with plasmid DNA stimulates CRISPR adaptation.

  16. Streptococcus pasteurianus septicemia

    Directory of Open Access Journals (Sweden)

    D Alex

    2013-01-01

    Full Text Available Streptococcus pasteurianus is part of the normal flora of the intestine. It has also been isolated from various infection sites. However, to date it has not been reported as a cause of fulminant septicemia and death. We report the post-mortem findings in a splenectomized hemophiliac patient with cirrhosis and concurrent human immunodeficiency virus (HIV, hepatitis B and hepatitis C infections.

  17. Prevalence and comparison of Streptococcus infantarius subsp. infantarius and Streptococcus gallolyticus subsp. macedonicus in raw and fermented dairy products from East and West Africa

    Science.gov (United States)

    Jans, Christoph; Kaindi, Dasel Wambua Mulwa; Böck, Désirée; Njage, Patrick Murigu Kamau; Kouamé-Sina, Sylvie Mireille; Bonfoh, Bassirou; Lacroix, Christophe; Meile, Leo

    2016-01-01

    Streptococcus infantarius subsp. infantarius (Sii) and Streptococcus gallolyticus subsp. macedonicus are members of the Streptococcus bovis/Streptococcus equinus complex (SBSEC) associated with human infections. SBSEC-related endocarditis was furthermore associated with rural residency in Southern Europe. SBSEC members are increasingly isolated as predominant species from fermented dairy products in Europe, Asia and Africa. African variants of Sii displayed dairy adaptations to lactose metabolism paralleling those of Streptococcus thermophilus including genome decay. In this study, the aim was to assess the prevalence of Sii and possibly other SBSEC members in dairy products of East and West Africa in order to identify their habitat, estimate their importance in dairy fermentation processes and determine geographic areas affected by this potential health risk. Presumptive SBSEC members were isolated on semi-selective M17 and SM agar media. Subsequent genotypic identification of isolates was based on rep-PCR fingerprinting and SBSEC-specific16S rRNA gene PCR assay. Detailed identification was achieved through application of novel primers enhancing the binding stringency in partial groES/groEL gene amplification and subsequent DNA sequencing. The presence of S. thermophilus-like lacS and lacZ genes in the SBSEC isolates was determined to elucidate the prevalence of this dairy adaptation. Isolates (n = 754) were obtained from 72 raw and 95 fermented milk samples from Côte d'Ivoire and Kenya on semi-selective agar media. Colonies of Sii were not detected from raw milk despite high microbial titers of approximately 106 CFU/mL on M17 agar medium. However, after spontaneous milk fermentation Sii was genotypically identified in 94.1% of Kenyan samples and 60.8% of Kenyan isolates. Sii prevalence in Côte d'Ivoire displayed seasonal variations in samples from 32.3% (June) to 40.0% (Dec/Jan) and isolates from 20.5% (June) to 27.7% (Dec/Jan) present at titers of 106–108

  18. Prevalence and comparison of Streptococcus infantarius subsp. infantarius and Streptococcus gallolyticus subsp. macedonicus in raw and fermented dairy products from East and West Africa.

    Science.gov (United States)

    Jans, Christoph; Kaindi, Dasel Wambua Mulwa; Böck, Désirée; Njage, Patrick Murigu Kamau; Kouamé-Sina, Sylvie Mireille; Bonfoh, Bassirou; Lacroix, Christophe; Meile, Leo

    2013-10-15

    Streptococcus infantarius subsp. infantarius (Sii) and Streptococcus gallolyticus subsp. macedonicus are members of the Streptococcus bovis/Streptococcus equinus complex (SBSEC) associated with human infections. SBSEC-related endocarditis was furthermore associated with rural residency in Southern Europe. SBSEC members are increasingly isolated as predominant species from fermented dairy products in Europe, Asia and Africa. African variants of Sii displayed dairy adaptations to lactose metabolism paralleling those of Streptococcus thermophilus including genome decay. In this study, the aim was to assess the prevalence of Sii and possibly other SBSEC members in dairy products of East and West Africa in order to identify their habitat, estimate their importance in dairy fermentation processes and determine geographic areas affected by this potential health risk. Presumptive SBSEC members were isolated on semi-selective M17 and SM agar media. Subsequent genotypic identification of isolates was based on rep-PCR fingerprinting and SBSEC-specific16S rRNA gene PCR assay. Detailed identification was achieved through application of novel primers enhancing the binding stringency in partial groES/groEL gene amplification and subsequent DNA sequencing. The presence of S. thermophilus-like lacS and lacZ genes in the SBSEC isolates was determined to elucidate the prevalence of this dairy adaptation. Isolates (n = 754) were obtained from 72 raw and 95 fermented milk samples from Côte d'Ivoire and Kenya on semi-selective agar media. Colonies of Sii were not detected from raw milk despite high microbial titers of approximately 10(6)CFU/mL on M17 agar medium. However, after spontaneous milk fermentation Sii was genotypically identified in 94.1% of Kenyan samples and 60.8% of Kenyan isolates. Sii prevalence in Côte d'Ivoire displayed seasonal variations in samples from 32.3% (June) to 40.0% (Dec/Jan) and isolates from 20.5% (June) to 27.7% (Dec/Jan) present at titers of 10

  19. Phosphoserine Phosphatase Is Required for Serine and One-Carbon Unit Synthesis in Hydrogenobacter thermophilus.

    Science.gov (United States)

    Kim, Keugtae; Chiba, Yoko; Kobayashi, Azusa; Arai, Hiroyuki; Ishii, Masaharu

    2017-11-01

    Hydrogenobacter thermophilus is an obligate chemolithoautotrophic bacterium of the phylum Aquificae and is capable of fixing carbon dioxide through the reductive tricarboxylic acid (TCA) cycle. The recent discovery of two novel-type phosphoserine phosphatases (PSPs) in H. thermophilus suggests the presence of a phosphorylated serine biosynthesis pathway; however, the physiological role of these novel-type metal-independent PSPs (iPSPs) in H. thermophilus has not been confirmed. In the present study, a mutant strain with a deletion of pspA, the catalytic subunit of iPSPs, was constructed and characterized. The generated mutant was a serine auxotroph, suggesting that the novel-type PSPs and phosphorylated serine synthesis pathway are essential for serine anabolism in H. thermophilus. As an autotrophic medium supplemented with glycine did not support the growth of the mutant, the reversible enzyme serine hydroxymethyltransferase does not appear to synthesize serine from glycine and may therefore generate glycine and 5,10-CH2-tetrahydrofolate (5,10-CH2-THF) from serine. This speculation is supported by the lack of glycine cleavage activity, which is needed to generate 5,10-CH2-THF, in H. thermophilus Determining the mechanism of 5,10-CH2-THF synthesis is important for understanding the fundamental anabolic pathways of organisms, because 5,10-CH2-THF is a major one-carbon donor that is used for the synthesis of various essential compounds, including nucleic and amino acids. The findings from the present experiments using a pspA deletion mutant have confirmed the physiological role of iPSPs as serine producers and show that serine is a major donor of one-carbon units in H. thermophilusIMPORTANCE Serine biosynthesis and catabolism pathways are intimately related to the metabolism of 5,10-CH2-THF, a one-carbon donor that is utilized for the biosynthesis of various essential compounds. For this reason, determining the mechanism of serine synthesis is important for

  20. Genetic Transformation of Streptococcus mutans

    OpenAIRE

    Perry, Dennis; Kuramitsu, Howard K.

    1981-01-01

    Three strains of Streptococcus mutans belonging to serotypes a, c, and f were transformed to streptomycin resistance by deoxyribonucleic acids derived from homologous and heterologous streptomycin-resistant strains of S. mutans and Streptococcus sanguis strain Challis. Homologous transformation of S. mutans was less efficient than heterologous transformation by deoxyribonucleic acids from other strains of S. mutans.

  1. Crystallization and structural studies of components of the protein-synthesizing system from Thermus thermophilus

    Science.gov (United States)

    Garber, M.; Davydova, N.; Eliseikina, I.; Fomenkova, N.; Gryaznova, O.; Gryshkovskaya, I.; Nevskaya, N.; Nikonov, S.; Rak, A.; Sedelnikova, S.; Serganov, A.; Shcherbakov, D.; Tishchenko, S.; Vysotskaya, V.; Zheltonosova, J.; Liljas, A.; Aevarsson, A.; Al-Karadaghi, S.

    1996-10-01

    A long-term program on crystallization and structural studies of the protein synthesis machinery components from an extreme thermophile Thermus thermophilus was set up at the Institute of Protein Research (Russia) about 15 years ago. These studies have recently revealed the structures of elongation factor G, aspartyl-tRNA synthetase and ribosomal proteins S6 and L1. Different components of the protein synthesis machinery from T.thermophilus are also being investigated in other groups and many important results have been obtained recently. Here we describe only some special problems on crystal handling and non-isomorphism that have been overcome during structural studies of EF-G and ribosomal proteins in our group. This paper presents also new data on the crystallization of ribosomal proteins S7, S8, S15, L22 and leucyl-tRNA synthetase from T.thermophilus.

  2. Rapid arsenite oxidation by Thermus aquaticus and Thermus thermophilus: Field and laboratory investigations

    Science.gov (United States)

    Gihring, T.M.; Druschel, G.K.; McCleskey, R.B.; Hamers, R.J.; Banfield, J.F.

    2001-01-01

    Thermus aquaticus and Thermus thermophilus, common inhabitants of terrestrial hot springs and thermally polluted domestic and industrial waters, have been found to rapidly oxidize arsenite to arsenate. Field investigations at a hot spring in Yellowstone National Park revealed conserved total arsenic transport and rapid arsenite oxidation occurring within the drainage channel. This environment was heavily colonized by Thermus aquaticus. In laboratory experiments, arsenite oxidation by cultures of Thermus aquaticus YT1 (previously isolated from Yellowstone National Park) and Thermus thermophilus HB8 was accelerated by a factor of over 100 relative to abiotic controls. Thermus aquaticus and Thermus thermophilus may therefore play a large and previously unrecognized role in determining arsenic speciation and bioavailability in thermal environments.

  3. Multi-site-specific 16S rRNA methyltransferase RsmF from Thermus thermophilus

    DEFF Research Database (Denmark)

    Demirci, Hasan; Larsen, Line H G; Hansen, Trine

    2010-01-01

    Cells devote a significant effort toward the production of multiple modified nucleotides in rRNAs, which fine tune the ribosome function. Here, we report that two methyltransferases, RsmB and RsmF, are responsible for all four 5-methylcytidine (m(5)C) modifications in 16S rRNA of Thermus...... thermophilus. Like Escherichia coli RsmB, T. thermophilus RsmB produces m(5)C967. In contrast to E. coli RsmF, which introduces a single m(5)C1407 modification, T. thermophilus RsmF modifies three positions, generating m(5)C1400 and m(5)C1404 in addition to m(5)C1407. These three residues are clustered near...

  4. Multi-site-specific 16S rRNA Methyltransferase RsmF from Thermus thermophilus

    Energy Technology Data Exchange (ETDEWEB)

    Demirci, H.; Larsen, L; Hansen, T; Rasmussen, A; Cadambi, A; Gregory, S; Kirpekar, F; Jogl, G

    2010-01-01

    Cells devote a significant effort toward the production of multiple modified nucleotides in rRNAs, which fine tune the ribosome function. Here, we report that two methyltransferases, RsmB and RsmF, are responsible for all four 5-methylcytidine (m{sup 5}C) modifications in 16S rRNA of Thermus thermophilus. Like Escherichia coli RsmB, T. thermophilus RsmB produces m{sup 5}C967. In contrast to E. coli RsmF, which introduces a single m{sup 5}C1407 modification, T. thermophilus RsmF modifies three positions, generating m{sup 5}C1400 and m{sup 5}C1404 in addition to m{sup 5}C1407. These three residues are clustered near the decoding site of the ribosome, but are situated in distinct structural contexts, suggesting a requirement for flexibility in the RsmF active site that is absent from the E. coli enzyme. Two of these residues, C1400 and C1404, are sufficiently buried in the mature ribosome structure so as to require extensive unfolding of the rRNA to be accessible to RsmF. In vitro, T. thermophilus RsmF methylates C1400, C1404, and C1407 in a 30S subunit substrate, but only C1400 and C1404 when naked 16S rRNA is the substrate. The multispecificity of T. thermophilus RsmF is potentially explained by three crystal structures of the enzyme in a complex with cofactor S-adenosyl-methionine at up to 1.3 {angstrom} resolution. In addition to confirming the overall structural similarity to E. coli RsmF, these structures also reveal that key segments in the active site are likely to be dynamic in solution, thereby expanding substrate recognition by T. thermophilus RsmF.

  5. "Streptococcus milleri" endocarditis caused by Streptococcus anginosus.

    Science.gov (United States)

    Woo, Patrick C Y; Tse, Herman; Chan, Kai-ming; Lau, Susanna K P; Fung, Ami M Y; Yip, Kam-tong; Tam, Dorothy M W; Ng, Kenneth H L; Que, Tak-lun; Yuen, Kwok-yung

    2004-02-01

    Unlike other viridans streptococci, members of the "Streptococcus milleri group" are often associated with abscess formation, but are only rare causes of infective endocarditis. Although it has been shown that almost all S. intermedius isolates and most S. constellatus isolates, but only 19% of S. anginosus isolates, were associated with abscess formation, no report has addressed the relative importance of the 3 species of the "S. milleri group" in infective endocarditis. During a 5-year period (April 1997 through March 2002), 6 cases of "S. milleri" endocarditis (out of 377 cases of infective endocarditis), that fulfil the Duke's criteria for the diagnosis of infective endocarditis, were encountered. All 6 "S. milleri" isolates were identified as S. anginosus by 16S ribosomal RNA (rRNA) gene sequencing. Three patients had underlying chronic rheumatic heart disease and 1 was an IV drug abuser. Five had monomicrobial bacteremia, and 1 had polymicrobial (S. anginosus, S. mitis, Granulicatella adiacens, and Slackia exigua) bacteremia. Two patients died. None of the 6 isolates were identified by the Vitek system (GPI) or the API system (20 STREP) at >95% confidence. All 6 isolates were sensitive to penicillin G (MIC 0.008-0.064 microg/mL), cefalothin, erythromycin, clindamycin, and vancomycin. Accurate identification to the species level, by 16S rRNA gene sequencing, in cases of bacteremia caused by members of the "S. milleri group", would have direct implication on the underlying disease process, hence guiding diagnosis and treatment. Infective endocarditis should be actively looked for in cases of monomicrobial S. anginosus bacteremia, especially if the organism is recovered in multiple blood cultures.

  6. Multiplex PCR-based identification of Streptococcus canis, Streptococcus zooepidemicus and Streptococcus dysgalactiae subspecies from dogs.

    Science.gov (United States)

    Moriconi, M; Acke, E; Petrelli, D; Preziuso, S

    2017-02-01

    Streptococcus canis (S. canis), Streptococcus equi subspecies zooepidemicus (S. zooepidemicus) and Streptococcus dysgalactiae subspecies (S. dysgalactiae subspecies) are β-haemolytic Gram positive bacteria infecting animals and humans. S. canis and S. zooepidemicus are considered as two of the major zoonotic species of Streptococcus, while more research is needed on S. dysgalactiae subspecies bacteria. In this work, a multiplex-PCR protocol was tested on strains and clinical samples to detect S. canis, S. dysgalactiae subspecies and S. equi subspecies bacteria in dogs. All strains were correctly identified as S. canis, S. equi subspecies or S. dysgalactiae subspecies by the multiplex-PCR. The main Streptococcus species isolated from symptomatic dogs were confirmed S. canis. The multiplex-PCR protocol described is a rapid, accurate and efficient method for identifying S. canis, S. equi subspecies and S. dysgalactiae subspecies in dogs and could be used for diagnostic purposes and for epidemiological studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Purification and characterization of thermophilin T, a novel bacteriocin produced by Streptococcus thermophilus ACA-DC 0040

    NARCIS (Netherlands)

    Aktypis, A.; Kalantzopoulos, G.; Huis Veld,in't J.H.J.; Brink, B. ten

    1998-01-01

    ACA-DC 0040 produced an antimicrobial agent, which was named thermophilin T, active against several lactic acid bacteria strains of different species and food spoilage bacteria, such as Clostridium sporogenes C22/10 and Cl. tyrobutyricum NCDO-1754. The crude antimicrobial compound is sensitive to

  8. [Electron transport chain in a thermophilic methane-oxidizing culture of Methylococcus thermophilus].

    Science.gov (United States)

    Sokolova, I G; Malashenko, Iu R; Romanovskaia, V A

    1981-01-01

    The electron transport chain was studied in the obligate methane oxidizing culture of Methylococcus thermophilus during the oxidation of methanol (the source of carbon) which is an oxidized derivative of methane as well as during the oxidation of hydroxylamine which is an intermediate in the oxidation of ammonium (the source of nitrogen) by Mc. thermophilus cells. Cytochromes a, b and c are involved in electron transport. Cytochrome cco and cytochrome c554 have been isolated from the cell-free extract of Mc. thermophilus and purified. A scheme for electron transport operating in the oxidation of methanol and hydroxylamine is suggested on the basis of studying the characteristics of these cytochromes. Cytochrome a was shown to be a component of terminal oxidase. Cytochromes b are connected with membranes and also found in the composition of hydroxylamine oxidase. Cytochrome cco and, possibly, terminal oxidase (cytochromes a) are involved, in the oxidation of CH3OH by methanol dehydrogenase, in electron transport; cytochrome c554 as well as cytochrome b and c in the composition of hydroxylamine oxidase participate in electron transport in the oxidation of NH2OH by hydroxylamine oxidase. The characteristics of the electron transport system in Mc. thermophilus are discussed.

  9. RNA Targeting by the Type III-A CRISPR-Cas Csm Complex of Thermus thermophilus

    NARCIS (Netherlands)

    Staals, R.H.J.; Zhu, Y.; Taylor, D.W.; Kornfeld, J.E.; Sharma, K.; Barendregt, A.; Koehorst, J.J.; Vlot, M.; Neupane, N.; Varossieau, K.; Sakamoto, K.; Suzuki, T.; Schaap, P.J.; Urlaub, H.; Heck, A.J.R.; Nogales, E.; Doudna, J.A.; Shinkai, A.; Oost, van der J.

    2014-01-01

    CRISPR-Cas is a prokaryotic adaptive immune system that provides sequence-specific defense against foreign nucleic acids. Here we report the structure and function of the effector complex of the Type III-A CRISPR-Cas system of Thermus thermophilus: the Csm complex (TtCsm). TtCsm is composed of five

  10. A reporter gene system for the precise measurement of promoter activity in Thermus thermophilus HB27.

    Science.gov (United States)

    Fujita, Atsushi; Sato, Takaaki; Koyama, Yoshinori; Misumi, Yoshio

    2015-11-01

    We developed a reporter gene system that enables precise analysis of promoter activity in Thermus thermophilus HB27. The reporter vector employs a promoterless β-galactosidase gene of Thermus spp. strain T2. However, T. thermophilus HB27 strain has three genes (TTP0042, TTP0220 and TTP0222) whose products have β-galactosidase activity, which would interfere with correct measurements of promoter activities. Thus, to eliminate this background activity, we disrupted all three of these genes to generate a host strain for measuring promoter expression as β-galactosidase activity. In addition, T. thermophilus strains also produce carotenoids called thermoxanthins that are yellow pigments. To avoid the influence of these carotenoids on the β-galactosidase assay, we also disrupted the phytoene synthase gene (crtB). The reporter gene system developed here is a powerful tool for studying transcriptional activity and the mechanisms that regulate gene expression in T. thermophilus HB27. We also showed that the crtB gene cassette could be used in repeated gene-disruption experiments to screen transformants by colony colour, thus eliminating the need for antibiotic resistance markers.

  11. Thermus thermophilus Glycoside Hydrolase Family 57 Branching Enzyme : Crystal Structure, Mechanism of Action, and Products Formed

    NARCIS (Netherlands)

    Palomo, Marta; Pijning, Tjaard; Booiman, Thijs; Dobruchowska, Justyna M.; Vlist, Jeroen van der; Kralj, Slavko; Planas, Antoni; Loos, Katja; Kamerling, Johannis P.; Dijkstra, Bauke W.; Maarel, Marc J.E.C. van der; Dijkhuizen, Lubbert; Leemhuis, Hans

    2011-01-01

    Branching enzyme (EC 2.4.1.18; glycogen branching enzyme; GBE) catalyzes the formation of alpha 1,6-branching points in glycogen. Until recently it was believed that all GBEs belong to glycoside hydrolase family 13 (GH13). Here we describe the cloning and expression of the Thermus thermophilus

  12. Streptococcus suis infection

    Science.gov (United States)

    Feng, Youjun; Zhang, Huimin; Wu, Zuowei; Wang, Shihua; Cao, Min; Hu, Dan; Wang, Changjun

    2014-01-01

    Streptococcus suis (S. suis) is a family of pathogenic gram-positive bacterial strains that represents a primary health problem in the swine industry worldwide. S. suis is also an emerging zoonotic pathogen that causes severe human infections clinically featuring with varied diseases/syndromes (such as meningitis, septicemia, and arthritis). Over the past few decades, continued efforts have made significant progress toward better understanding this zoonotic infectious entity, contributing in part to the elucidation of the molecular mechanism underlying its high pathogenicity. This review is aimed at presenting an updated overview of this pathogen from the perspective of molecular epidemiology, clinical diagnosis and typing, virulence mechanism, and protective antigens contributing to its zoonosis. PMID:24667807

  13. Mutacins of Streptococcus mutans

    Directory of Open Access Journals (Sweden)

    Regianne Umeko Kamiya

    2011-12-01

    Full Text Available The colonization and accumulation of Streptococcus mutans are influenced by various factors in the oral cavity, such as nutrition and hygiene conditions of the host, salivary components, cleaning power and salivary flow and characteristics related with microbial virulence factors. Among these virulence factors, the ability to synthesize glucan of adhesion, glucan-binding proteins, lactic acid and bacteriocins could modify the infection process and pathogenesis of this species in the dental biofilm. This review will describe the role of mutacins in transmission, colonization, and/or establishment of S. mutans, the major etiological agent of human dental caries. In addition, we will describe the method for detecting the production of these inhibitory substances in vitro (mutacin typing, classification and diversity of mutacins and the regulatory mechanisms related to its synthesis.

  14. Osteomyelitis complicating Streptococcus milleri endocarditis.

    Science.gov (United States)

    Barham, N. J.; Flint, E. J.; Mifsud, R. P.

    1990-01-01

    A patient with osteomyelitis of the spine complicating bacterial endocarditis due to Streptococcus milleri is discussed. To our knowledge, this is the first time this organism has been associated with this complication. Images Figure 1 PMID:2385559

  15. Molecular cloning, sequencing and expression in Escherichia coli cells Thermus thermophilus leucyl-tRNA synthetase

    Directory of Open Access Journals (Sweden)

    Kovalenko O. P.

    2011-12-01

    Full Text Available Aim. Cloning and sequencing of the T. thermophilus leucyl-tRNA synthetase (LeuRSTT followed by the creation of genetically engineered construct for protein expression in E.coli cells and its purification. Methods. Searching for the LeuRSTT gene was performed by Southern blot hybridization with chromosomal DNA, where digoxigenin-labeled PCR fragments of DNA were used as probes. Results. The gene of T. thermophilus HB27 leucyl-tRNA synthetase was cloned and sequenced. The open reading frame encodes a polypeptide chain of 878 amino acid residues in length (molecular mass 101 kDa. Comparison of the amino acid sequence of T. thermophilus LeuRS with that of the enzymes from other organisms showed that LeuRSTT was a part of the group of similar enzymes of prokaryotes, formed by the proteins of protobacteriae, rickettsia and mitochondria of eukaryotes. The resulting phylogenetic tree of LeuRSs reveals dichotomous branching into two lines: prokaryotic/eukaryotic mitochondrial and arhaeal/eukaryotic cytosolic proteins. Differences between prokaryotic and arhaeal branches of the LeuRSs phylogenetic tree are primarily due to the structure of two domains of the enzyme – the editing and the C-terminal. T. thermophilus LeuRS was expressed in E. coli cells by cloning the corresponding gene into pET29b vector. Conclusions. The cloned T. thermophilus leuS gene and expressed recombinant protein will be used for structural and functional studies on LeuRSTT, including X-ray analysis of the enzyme and its mutant forms in complex with different substrates

  16. Streptococcus zooepidemicus infection in sheep.

    Science.gov (United States)

    Stevenson, R G

    1974-07-01

    Fibrinous pericarditis, fibrinous pleuritis and pneumonia associated with Streptococcus zooepidemicus were observed in two lambs in a small flock of sheep. These lesions were reproduced in lambs inoculated intratracheally with Streptococcus zooepidemicus. Clinical signs included pyrexia, serous to mucopurulent nasal discharge, dyspnea and depression followed by death in six to seven days. Histologically the tissue changes were characterized by an acute inflammatory response involving bronchioles and alveoli, fibrinous pleuritis and fibrinous pericarditis.

  17. Colecistitis aguda por Streptococcus constellatus

    OpenAIRE

    M Sandra Gómez-Canosa; Cristina Lijó-Carballeda; Begoña Vázquez-Vázquez; M José Bello-Peón

    2016-01-01

    Presentamos el caso de una paciente de edad avanzada y significativa comorbilidad que se diagnosticó de colecistitis aguda por Streptococcus constellatus. El drenaje de la vesícula biliar por colecistostomía percutánea, asociado a penicilinas, ha conseguido una evolución favorable. We report the case of a patient of advanced age and significant comorbidity diagnosed acute cholecystitis by Streptococcus constellatus. Gallbladder drainage by percutaneous cholecystostomy associated ...

  18. Diversity of Integrative and Conjugative Elements of Streptococcus salivarius and Their Intra- and Interspecies Transfer.

    Science.gov (United States)

    Dahmane, Narimane; Libante, Virginie; Charron-Bourgoin, Florence; Guédon, Eric; Guédon, Gérard; Leblond-Bourget, Nathalie; Payot, Sophie

    2017-07-01

    Integrative and conjugative elements (ICEs) are widespread chromosomal mobile genetic elements which can transfer autonomously by conjugation in bacteria. Thirteen ICEs with a conjugation module closely related to that of ICESt3 of Streptococcus thermophilus were characterized in Streptococcus salivarius by whole-genome sequencing. Sequence comparison highlighted ICE evolution by shuffling of 3 different integration/excision modules (for integration in the 3' end of the fda, rpsI, or rpmG gene) with the conjugation module of the ICESt3 subfamily. Sequence analyses also pointed out a recombination occurring at oriT (likely mediated by the relaxase) as a mechanism of ICE evolution. Despite a similar organization in two operons including three conserved genes, the regulation modules show a high diversity (about 50% amino acid sequence divergence for the encoded regulators and presence of unrelated additional genes) with a probable impact on the regulation of ICE activity. Concerning the accessory genes, ICEs of the ICESt3 subfamily appear particularly rich in restriction-modification systems and orphan methyltransferase genes. Other cargo genes that could confer a selective advantage to the cell hosting the ICE were identified, in particular, genes for bacteriocin synthesis and cadmium resistance. The functionality of 2 ICEs of S. salivarius was investigated. Autonomous conjugative transfer to other S. salivarius strains, to S. thermophilus, and to Enterococcus faecalis was observed. The analysis of the ICE-fda border sequence in these transconjugants allowed the localization of the DNA cutting site of the ICE integrase.IMPORTANCE The ICESt3 subfamily of ICEs appears to be widespread in streptococci and targets diverse chromosomal integration sites. These ICEs carry diverse cargo genes that can confer a selective advantage to the host strain. The maintenance of these mobile genetic elements likely relies in part on self-encoded restriction-modification systems. In

  19. Antimicrobial Resistant Streptococcus pneumoniae

    Directory of Open Access Journals (Sweden)

    B Khanal

    2010-09-01

    Full Text Available Introduction: Pneumococcal infections are important cause of morbidity and mortality. Knowledge of antimicrobial susceptibility patterns plays important role in the selection of appropriate therapy. Present study was undertaken to analyze the susceptibility patterns of pneumococcal isolates against commonly used antimicrobials with special reference to determination of minimum inhibitory concentration (MIC of penicillin in a tertiary care hospital in eastern Nepal. Methods: Twenty-six strains of S. pneumoniae isolated from various clinical specimens submitted to microbiology laboratory were evaluated. All isolates were tested for antimicrobial susceptibility by disk diffusion method. MIC of penicillin was tested by broth dilution method. Results: Of the total isolates 19 (73% were from invasive infections. Seven isolates were resistant to cotrimoxazole. No resistance to penicillin was seen in disk diffusion testing. Less susceptibility to penicillin (MIC 0.1-1.0 mg/L was observed in five (17% isolates. High level resistance to penicillin was not detected. One isolate was multidrug resistant. Conclusions: S. pneumoniaeisolates with intermediate resistance to penicillin prevail in Tertiary Care Hospital in eastern Nepal, causing invasive and noninvasive infections. As intermediate resistance is not detected in routine susceptibility testing, determination of MIC is important. It helps not only in the effective management of life threatening infections but is also essential in continuous monitoring and early detection of resistance. In addition, further study on pneumococcal infections, its antimicrobial resistance profile and correlation with clinical and epidemiological features including serotypes and group prevalence is recommended in future. Keywords: antimicrobial susceptibility pattern, penicillin, Streptococcus pneumoniae.

  20. Antigens of Streptococcus sanguis

    Science.gov (United States)

    Rosan, Burton

    1973-01-01

    An antigenic analysis of the alpha-hemolytic streptococci isolated from dental plaque was performed by use of antisera against a strain of Streptococcus sanguis (M-5) which was isolated from dental plaque. Immunoelectrophoretic and Ouchterlony tests of Rantz and Randall extracts of 45 strains gave positive reactions with the M-5 antisera. These strains represented 60% of the strains tested. The number of antigens which could be identified in these extracts varied from one to five and were designated a to e. The a antigen was found in 36 of the strains tested, including reference strains of S. sanguis and the group H streptococci. The strains reacting with the M-5 antisera were divided into two majors types: type I consisted of 23 strains in which the a antigen was found alone or with one or more of the c, d, and e antigens; type II consisted of 13 strains in which both the a and b antigens were found with or without one or more of the c, d, and e antigens. The remaining strains contained, either singly or in combination, the b, c, d, and e antigens but not the a antigen. Biochemical tests of representatives of each serotype and reference strains indicated that strains reacting with M-5 antisera were S. sanguis. These findings suggest that S. sanguis strains share common physiological and serological properties. Images PMID:4633291

  1. PATOGENESITAS Streptococcus Agalactiae DAN Streptococcus Iniae PADA IKAN NILA (Oreochromis Niloticus) [Pathogenesitas of Streptococcus Agalactiae and Streptococcus Iniae in Nile Tilapia (Oreochromis Niloticus)

    OpenAIRE

    Daenuri, Dudung; Sinaga, Walson Halomoan

    2011-01-01

    The objectives of this study are to test the pathogenicity of Streptococcus agalactiae and Streptococcus iniae in Nile Tilapia(Oreochromis niloticus) A challenge test was carried out in the Laboratory of Semarang Fish Quarantine. The method used in this study was the Completely Randomize Design(CRD) with three bacterial treatments Streptococcus agalactiae, Streptococcus iniae and control, three dose 107 ,108 , 109 with three replications for each treatment. The observed parameters include id...

  2. A Highly Arginolytic Streptococcus Species That Potently Antagonizes Streptococcus mutans.

    Science.gov (United States)

    Huang, Xuelian; Palmer, Sara R; Ahn, Sang-Joon; Richards, Vincent P; Williams, Matthew L; Nascimento, Marcelle M; Burne, Robert A

    2016-01-29

    The ability of certain oral biofilm bacteria to moderate pH through arginine metabolism by the arginine deiminase system (ADS) is a deterrent to the development of dental caries. Here, we characterize a novel Streptococcus strain, designated strain A12, isolated from supragingival dental plaque of a caries-free individual. A12 not only expressed the ADS pathway at high levels under a variety of conditions but also effectively inhibited growth and two intercellular signaling pathways of the dental caries pathogen Streptococcus mutans. A12 produced copious amounts of H2O2 via the pyruvate oxidase enzyme that were sufficient to arrest the growth of S. mutans. A12 also produced a protease similar to challisin (Sgc) of Streptococcus gordonii that was able to block the competence-stimulating peptide (CSP)-ComDE signaling system, which is essential for bacteriocin production by S. mutans. Wild-type A12, but not an sgc mutant derivative, could protect the sensitive indicator strain Streptococcus sanguinis SK150 from killing by the bacteriocins of S. mutans. A12, but not S. gordonii, could also block the XIP (comX-inducing peptide) signaling pathway, which is the proximal regulator of genetic competence in S. mutans, but Sgc was not required for this activity. The complete genome sequence of A12 was determined, and phylogenomic analyses compared A12 to streptococcal reference genomes. A12 was most similar to Streptococcus australis and Streptococcus parasanguinis but sufficiently different that it may represent a new species. A12-like organisms may play crucial roles in the promotion of stable, health-associated oral biofilm communities by moderating plaque pH and interfering with the growth and virulence of caries pathogens. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  3. Metal influence on metallothionein synthesis in the hydrothermal vent mussel Bathymodiolus thermophilus

    OpenAIRE

    Hardivillier, Yann; Denis, Françoise; Demattei, Marie-Véronique; Bustamante, Paco; Laulier, Marc; Cosson, Richard,

    2006-01-01

    International audience; The present study reports on the metallothionein expression in the hydrothermal vent mussel Bathymodiolus thermophilus. Metallothioneins (MT) are proteins involved in intracellular metal regulation and conserved throughout the animal kingdom. The hydrothermal vent environment presents peculiarities (high levels of sulfides and metals, low pH, anoxia) that may have driven associated species to develop original evolutionary ways to face these extreme living conditions. M...

  4. Colecistitis aguda por Streptococcus constellatus

    Directory of Open Access Journals (Sweden)

    M Sandra Gómez-Canosa

    2016-03-01

    Full Text Available Presentamos el caso de una paciente de edad avanzada y significativa comorbilidad que se diagnosticó de colecistitis aguda por Streptococcus constellatus. El drenaje de la vesícula biliar por colecistostomía percutánea, asociado a penicilinas, ha conseguido una evolución favorable. We report the case of a patient of advanced age and significant comorbidity diagnosed acute cholecystitis by Streptococcus constellatus. Gallbladder drainage by percutaneous cholecystostomy associated with penicillins has achieved a favorable outcome.

  5. Occurrence, isolation and DNA identification of Streptococcus ...

    African Journals Online (AJOL)

    ajl yemi

    2011-11-28

    Nov 28, 2011 ... A total of 12 strains were tested by DNA identification analysis and these indigenous isolates were unambiguously ... To our knowledge, this is the first report on the isolation and molecular characterization of. S. thermophilus ..... Identification of lactic acid bacteria isolated from Tarhana, a traditional Turkish.

  6. The halophilic alkalithermophile Natranaerobius thermophilus adapts to multiple environmental extremes using a large repertoire of Na(K)/H antiporters.

    Science.gov (United States)

    Mesbah, Noha M; Cook, Gregory M; Wiegel, Juergen

    2009-10-01

    Natranaerobius thermophilus is an unusual extremophile because it is halophilic, alkaliphilic and thermophilic, growing optimally at 3.5 M Na(+), pH(55 degrees C) 9.5 and 53 degrees C. Mechanisms enabling this tripartite lifestyle are essential for understanding how microorganisms grow under inhospitable conditions, but remain unknown, particularly in extremophiles growing under multiple extremes. We report on the response of N. thermophilus to external pH at high salt and elevated temperature and identify mechanisms responsible for this adaptation. N. thermophilus exhibited cytoplasm acidification, maintaining an unanticipated transmembrane pH gradient of 1 unit over the entire extracellular pH range for growth. N. thermophilus uses two distinct mechanisms for cytoplasm acidification. At extracellular pH values at and below the optimum, N. thermophilus utilizes at least eight electrogenic Na(+)(K(+))/H(+) antiporters for cytoplasm acidification. Characterization of these antiporters in antiporter-deficient Escherichia coli KNabc showed overlapping pH profiles (pH 7.8-10.0) and Na(+) concentrations for activity (K(0.5) values 1.0-4.4 mM), properties that correlate with intracellular conditions of N. thermophilus. As the extracellular pH increases beyond the optimum, electrogenic antiport activity ceases, and cytoplasm acidification is achieved by energy-independent physiochemical effects (cytoplasmic buffering) potentially mediated by an acidic proteome. The combination of these strategies allows N. thermophilus to grow over a range of extracellular pH and Na(+) concentrations and protect biomolecules under multiple extreme conditions.

  7. The halophilic alkalithermophile Natranaerobius thermophilus adapts to multiple environmental extremes using a large repertoire of Na+(K+)/H+ antiporters

    Science.gov (United States)

    Mesbah, Noha M; Cook, Gregory M; Wiegel, Juergen

    2009-01-01

    Natranaerobius thermophilus is an unusual extremophile because it is halophilic, alkaliphilic and thermophilic, growing optimally at 3.5 M Na+, pH55°C 9.5 and 53°C. Mechanisms enabling this tripartite lifestyle are essential for understanding how microorganisms grow under inhospitable conditions, but remain unknown, particularly in extremophiles growing under multiple extremes. We report on the response of N. thermophilus to external pH at high salt and elevated temperature and identify mechanisms responsible for this adaptation. N. thermophilus exhibited cytoplasm acidification, maintaining an unanticipated transmembrane pH gradient of 1 unit over the entire extracellular pH range for growth. N. thermophilus uses two distinct mechanisms for cytoplasm acidification. At extracellular pH values at and below the optimum, N. thermophilus utilizes at least eight electrogenic Na+(K+)/H+ antiporters for cytoplasm acidification. Characterization of these antiporters in antiporter-deficient Escherichia coli KNabc showed overlapping pH profiles (pH 7.8–10.0) and Na+ concentrations for activity (K0.5 values 1.0–4.4 mM), properties that correlate with intracellular conditions of N. thermophilus. As the extracellular pH increases beyond the optimum, electrogenic antiport activity ceases, and cytoplasm acidification is achieved by energy-independent physiochemical effects (cytoplasmic buffering) potentially mediated by an acidic proteome. The combination of these strategies allows N. thermophilus to grow over a range of extracellular pH and Na+ concentrations and protect biomolecules under multiple extreme conditions. PMID:19708921

  8. Recommended conservation of the names Streptococcus sanguis, Streptococcus rattus, Streptococcus cricetus, and seven other names included in the Approved Lists of Bacterial Names. Request for an opinion

    DEFF Research Database (Denmark)

    Kilian, Mogens

    2001-01-01

    With reference to the first Principle of the International Code of Nomenclature of Bacteria, which emphasizes stability of names, it is proposed that the original names Streptococcus sanguis, Streptococcus rattus, Streptococcus cricetus, Erwinia ananas, Eubacterium tarantellus, Lactobacillus sake...

  9. Suicin 3908, a new lantibiotic produced by a strain of Streptococcus suis serotype 2 isolated from a healthy carrier pig.

    Directory of Open Access Journals (Sweden)

    Katy Vaillancourt

    Full Text Available While Streptococcus suis serotype 2 is known to cause severe infections in pigs, it can also be isolated from the tonsils of healthy animals that do not develop infections. We hypothesized that S. suis strains in healthy carrier pigs may have the ability to produce bacteriocins, which may contribute to preventing infections by pathogenic S. suis strains. Two of ten S. suis serotype 2 strains isolated from healthy carrier pigs exhibited antibacterial activity against pathogenic S. suis isolates. The bacteriocin produced by S. suis 3908 was purified to homogeneity using a three-step procedure: ammonium sulfate precipitation, cationic exchange HPLC, and reversed-phase HPLC. The bacteriocin, called suicin 3908, had a low molecular mass; was resistant to heat, pH, and protease treatments; and possessed membrane permeabilization activity. Additive effects were obtained when suicin 3908 was used in combination with penicillin G or amoxicillin. The amino acid sequence of suicin 3908 suggested that it is lantibiotic-related and made it possible to identify a bacteriocin locus in the genome of S. suis D12. The putative gene cluster involved in suicin production by S. suis 3908 was amplified by PCR, and the sequence analysis revealed the presence of nine open reading frames (ORFs, including the structural gene and those required for the modification of amino acids, export, regulation, and immunity. Suicin 3908, which is encoded by the suiA gene, exhibited approximately 50% identity with bovicin HJ50 (Streptococcus bovis, thermophilin 1277 (Streptococcus thermophilus, and macedovicin (Streptococcus macedonicus. Given that S. suis 3908 cannot cause infections in animal models, that it is susceptible to conventional antibiotics, and that it produces a bacteriocin with antibacterial activity against all pathogenic S. suis strains tested, it could potentially be used to prevent infections and to reduce antibiotic use by the swine industry.

  10. Cloning, expression and purification of D-Tyr-tRNATyr-deacylase from Thermus thermophilus

    Directory of Open Access Journals (Sweden)

    Rybak M. Yu.

    2015-06-01

    Full Text Available D-Tyr-tRNATyr-deacylase (DTD is a conservative enzyme, found in all domains of life, which ensures an additional checkpoint in the recycling of misaminoacylated D-Tyr-tRNATyr. DTD is capable of accelerating the hydrolysis of the ester linkage of D-Tyr-tRNATyr producing a free tRNA and D-tyrosine, thereby preventing an incorrect incorporation of D-amino acids into proteins. Deacylase distinguishes between D- and L-aminoacyl moieties and does not hydrolyze L-aminoacylated tRNA. The structural bases of this specificity and the mechanism of D-aminoacyl-tRNA hydrolysis are poorly understood. Aim. To clone D-Tyr-tRNATyr-deacylase from T. thermophilus (DTDTT, optimize the conditions for its expression in E.coli and develop an efficient purification procedure yielding the high quality enzyme suitable for the structural and functional studies. Methods. For amplification of DTD gene from T. thermophilus genomic DNA and its cloning into the pProEXHTb expression vector modern techniques were applied. Purification of the recombinant DTD protein was done with three types of column chromatography. His-tag was cleaved out from DTD by TEV protease. The cleavage was confirmed by Western blot analysis with anti-His-tag antibodies. Molecular weight of purified DTDTT was determined by the gel-filtration. Results. The expression construct pProEXHTb, containing DTD sequence from T. thermophilus, was obtained and successfully expressed in the BL21(DE3pLysS E.coli strain. The protein of interest was purified to homogeneity by the combination of affinity (Ni-NTA, anion-exchange (Q-Sepharose and size-exclusion (Superdex S 200 chromatographies. 2 mg of more than 90% pure recombinant DTD can be obtained from 1 L of bacterial culture. Molecular weight of purified DTD from T. thermophilus was determined to be 32 kDa, suggesting its dimeric structure. Conclusions. The pProEXHTb expression vector can be used for expression of DTD from T. thermophilus. The preparative amounts of

  11. Recombination-deficient Streptococcus sanguis

    Energy Technology Data Exchange (ETDEWEB)

    Daneo-Moore, L.; Volpe, A.

    1985-05-01

    A UV-sensitive derivative was obtained from Streptococcus sanguis Challis. The organism could be transformed with a number of small streptococcal plasmids at frequencies equal to, or 1 logarithm below, the transformation frequencies for the parent organism. However, transformation with chromosomal DNA was greatly impaired in the UV-sensitive derivative.

  12. Gene Repertoire Evolution of Streptococcus pyogenes Inferred from Phylogenomic Analysis with Streptococcus canis and Streptococcus dysgalactiae

    Science.gov (United States)

    Lefébure, Tristan; Richards, Vince P.; Lang, Ping; Pavinski-Bitar, Paulina; Stanhope, Michael J.

    2012-01-01

    Streptococcus pyogenes, is an important human pathogen classified within the pyogenic group of streptococci, exclusively adapted to the human host. Our goal was to employ a comparative evolutionary approach to better understand the genomic events concomitant with S. pyogenes human adaptation. As part of ascertaining these events, we sequenced the genome of one of the potential sister species, the agricultural pathogen S. canis, and combined it in a comparative genomics reconciliation analysis with two other closely related species, Streptococcus dysgalactiae and Streptococcus equi, to determine the genes that were gained and lost during S. pyogenes evolution. Genome wide phylogenetic analyses involving 15 Streptococcus species provided convincing support for a clade of S. equi, S. pyogenes, S. dysgalactiae, and S. canis and suggested that the most likely S. pyogenes sister species was S. dysgalactiae. The reconciliation analysis identified 113 genes that were gained on the lineage leading to S. pyogenes. Almost half (46%) of these gained genes were phage associated and 14 showed significant matches to experimentally verified bacteria virulence factors. Subsequent to the origin of S. pyogenes, over half of the phage associated genes were involved in 90 different LGT events, mostly involving different strains of S. pyogenes, but with a high proportion involving the horse specific pathogen S. equi subsp. equi, with the directionality almost exclusively (86%) in the S. pyogenes to S. equi direction. Streptococcus agalactiae appears to have played an important role in the evolution of S. pyogenes with a high proportion of LGTs originating from this species. Overall the analysis suggests that S. pyogenes adaptation to the human host was achieved in part by (i) the integration of new virulence factors (e.g. speB, and the sal locus) and (ii) the construction of new regulation networks (e.g. rgg, and to some extent speB). PMID:22666370

  13. Adhesion of streptococcus rattus and streptococcus mutans to metal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Branting, C.; Linder, L.E.; Sund, M.-L.; Oden, A.; Wiatr-Adamczak, E.

    1988-01-01

    The adhesion of Streptococcus rattus BHT and Streptococcus mutans IB to metal specimens of amalgam, silver, tin and copper was studied using (6-/sup 3/H) thymidine labeled cells. In the standard assay the metal specimens were suspended by a nylon thread in an adhesion solution containing a chemically defined bacterial growth medium (FMC), sucrose, and radiolabeled bacteria. Maximum amounts of adhering bacteria were obtained after about 100 min of incubation. Saturation of the metal specimens with bacteria was not observed. Both strains also adhered in the absence of sucrose, indicating that glucan formation was not necessary for adhesion. However, in the presence of glucose, adhesion was only 26-45% of that observed in the presence of equimolar sucrose. Sucrose-dependent stimulation of adhesion seemed to be due to increased cell-to-cell adhesion capacity. Isolated radiolabeled water-insoluble and water-soluble polysaccharides produced from sucrose by S. rattus BHT were not adsorbed to the metal surfaces.

  14. Antibiotic Susceptibility of Periodontal Streptococcus Constellatus and Streptococcus Intermedius Clinical Isolates

    NARCIS (Netherlands)

    Rams, Thomas E; Feik, Diane; Mortensen, Joel E; Degener, John E; van Winkelhoff, Arie J

    2014-01-01

    Background: Streptococcus constellatus and Streptococcus intermedius in subgingival dental plaque biofilms may contribute to forms of periodontitis that resist treatment with conventional mechanical root debridement/surgical procedures and may additionally participate in some extraoral infections.

  15. Streptococcus oligofermentans inhibits Streptococcus mutans in biofilms at both neutral pH and cariogenic conditions

    NARCIS (Netherlands)

    Bao, X.; de Soet, J.J.; Tong, H.; Gao, X.; He, L.; van Loveren, C.; Deng, D.M.

    2015-01-01

    Homeostasis of oral microbiota can be maintained through microbial interactions. Previous studies showed that Streptococcus oligofermentans, a non-mutans streptococci frequently isolated from caries-free subjects, inhibited the cariogenic Streptococcus mutans by the production of hydrogen peroxide

  16. Linkage Analyses of Extracellular Glucans from Streptococcus sanguis and Streptococcus mitior

    Science.gov (United States)

    Freedman, M.; Birkhed, D.; Coykendall, A.; Rizzo, D.

    1979-01-01

    Similar α-(1→6) linkage-rich, soluble, extracellular glucans have been isolated from six strains of two genetically distinct groups of Streptococcus sanguis and three strains of Streptococcus mitior. PMID:457265

  17. Acquisition through horizontal gene transfer of plasmid pSMA198 by Streptococcus macedonicus ACA-DC 198 points towards the dairy origin of the species.

    Science.gov (United States)

    Papadimitriou, Konstantinos; Anastasiou, Rania; Maistrou, Eleni; Plakas, Thomas; Papandreou, Nikos C; Hamodrakas, Stavros J; Ferreira, Stéphanie; Supply, Philip; Renault, Pierre; Pot, Bruno; Tsakalidou, Effie

    2015-01-01

    Streptococcus macedonicus is an intriguing streptococcal species whose most frequent source of isolation is fermented foods similarly to Streptococcus thermophilus. However, S. macedonicus is closely related to commensal opportunistic pathogens of the Streptococcus bovis/Streptococcus equinus complex. We analyzed the pSMA198 plasmid isolated from the dairy strain Streptococcus macedonicus ACA-DC 198 in order to provide novel clues about the main ecological niche of this bacterium. pSMA198 belongs to the narrow host range pCI305/pWV02 family found primarily in lactococci and to the best of our knowledge it is the first such plasmid to be reported in streptococci. Comparative analysis of the pSMA198 sequence revealed a high degree of similarity with plasmids isolated from Lactococcus lactis strains deriving from milk or its products. Phylogenetic analysis of the pSMA198 Rep showed that the vast majority of closely related proteins derive from lactococcal dairy isolates. Additionally, cloning of the pSMA198 ori in L. lactis revealed a 100% stability of replication over 100 generations. Both pSMA198 and the chromosome of S. macedonicus exhibit a high percentage of potential pseudogenes, indicating that they have co-evolved under the same gene decay processes. We identified chromosomal regions in S. macedonicus that may have originated from pSMA198, also supporting a long co-existence of the two replicons. pSMA198 was also found in divergent biotypes of S. macedonicus and in strains isolated from dispersed geographic locations (e.g. Greece and Switzerland) showing that pSMA198's acquisition is not a recent event. Here we propose that S. macedonicus acquired plasmid pSMA198 from L. lactis via an ancestral genetic exchange event that took place most probably in milk or dairy products. We provide important evidence that point towards the dairy origin of this species.

  18. Acquisition through horizontal gene transfer of plasmid pSMA198 by Streptococcus macedonicus ACA-DC 198 points towards the dairy origin of the species.

    Directory of Open Access Journals (Sweden)

    Konstantinos Papadimitriou

    Full Text Available Streptococcus macedonicus is an intriguing streptococcal species whose most frequent source of isolation is fermented foods similarly to Streptococcus thermophilus. However, S. macedonicus is closely related to commensal opportunistic pathogens of the Streptococcus bovis/Streptococcus equinus complex.We analyzed the pSMA198 plasmid isolated from the dairy strain Streptococcus macedonicus ACA-DC 198 in order to provide novel clues about the main ecological niche of this bacterium. pSMA198 belongs to the narrow host range pCI305/pWV02 family found primarily in lactococci and to the best of our knowledge it is the first such plasmid to be reported in streptococci. Comparative analysis of the pSMA198 sequence revealed a high degree of similarity with plasmids isolated from Lactococcus lactis strains deriving from milk or its products. Phylogenetic analysis of the pSMA198 Rep showed that the vast majority of closely related proteins derive from lactococcal dairy isolates. Additionally, cloning of the pSMA198 ori in L. lactis revealed a 100% stability of replication over 100 generations. Both pSMA198 and the chromosome of S. macedonicus exhibit a high percentage of potential pseudogenes, indicating that they have co-evolved under the same gene decay processes. We identified chromosomal regions in S. macedonicus that may have originated from pSMA198, also supporting a long co-existence of the two replicons. pSMA198 was also found in divergent biotypes of S. macedonicus and in strains isolated from dispersed geographic locations (e.g. Greece and Switzerland showing that pSMA198's acquisition is not a recent event.Here we propose that S. macedonicus acquired plasmid pSMA198 from L. lactis via an ancestral genetic exchange event that took place most probably in milk or dairy products. We provide important evidence that point towards the dairy origin of this species.

  19. Streptococcus milleri and surgical sepsis.

    Science.gov (United States)

    Tresadern, J. C.; Farrand, R. J.; Irving, M. H.

    1983-01-01

    For many years Viridans streptococci have been considered as commensal organisms in a wide variety of sites in the human body and only regarded as significant pathogens in subacute bacterial endocarditis. However, in recent years some reports have suggested that a particular species, Streptococcus milleri, can be a virulent pathogen, producing life-threatening sepsis particularly in surgical patients. We review here our experience of this organism in 23 general surgical patients over a 3 year period, and postulate that prophylactic use of antibiotic combinations such as gentamicin and metronidazole in patients undergoing colo-rectal surgery may be a factor promoting its emergence as a significant pathogen. Patients with established sepsis due to Streptococcus milleri should be considered for long-term antibiotic therapy as part of the treatment of their abscesses. PMID:6830135

  20. First Isolation of Streptococcus halichoeri and Streptococcus phocae from a Steller Sea Lion (Eumetopias jubatus) in South Korea.

    Science.gov (United States)

    Lee, Kichan; Kim, Ji-Yeon; Jung, Suk Chan; Lee, Hee-Soo; Her, Moon; Chae, Chanhee

    2016-01-01

    Streptococcus species are emerging potential pathogens in marine mammals. We report the isolation and identification of Streptococcus halichoeri and Streptococcus phocae in a Steller sea lion (Eumetopias jubatus) in South Korea.

  1. Hydrolytic enzymes of "Streptococcus milleri".

    Science.gov (United States)

    Ruoff, K L; Ferraro, M J

    1987-01-01

    Seventy-two isolates classified as "Streptococcus milleri" were examined for the presence of various hydrolytic enzymes. While no protein or lipid-degrading activities were demonstrated, some isolates showed DNase and mucopolysaccharide-degrading activities. Beta-hemolytic isolates were more likely to produce these enzymes than were nonhemolytic strains. Isolates of one "S. milleri" biotype (mannitol fermentation positive) were uniformly devoid of all enzyme activities tested. PMID:2958496

  2. Streptococcus agalactiae mastitis: a review.

    OpenAIRE

    Keefe, G P

    1997-01-01

    Streptococcus agalactiae continues to be a major cause of subclinical mastitis in dairy cattle and a source of economic loss for the industry. Veterinarians are often asked to provide information on herd level control and eradication of S. agalactiae mastitis. This review collects and collates relevant publications on the subject. The literature search was conducted in 1993 on the Agricola database. Articles related to S. agalactiae epidemiology, pathogen identification techniques, milk quali...

  3. Streptococcus intermedius, Streptococcus constellatus, and Streptococcus anginosus ("Streptococcus milleri group") are of different clinical importance and are not equally associated with abscess.

    Science.gov (United States)

    Claridge, J E; Attorri, S; Musher, D M; Hebert, J; Dunbar, S

    2001-05-15

    Difficulties in distinguishing organisms of the "Streptococcus milleri group" (SMG; Streptococcus intermedius, Streptococcus constellatus, and Streptococcus anginosus), have caused ambiguity in determining their pathogenic potential. We reviewed 118 cases in which SMG isolates had been identified using 16S rDNA sequence. S. constellatus and S. anginosus were isolated far more frequently than was S. intermedius. Nearly all isolates of S. intermedius and most isolates of S. constellatus, but only 19% of those of S. anginosus, were associated with abscess. Our findings suggest that speciation of the SMG may guide diagnostic evaluation, give insight into the possible role of coinfecting organisms, and help assess the need to search for occult abscess.

  4. Molecular pathogenicity of Streptococcus anginosus.

    Science.gov (United States)

    Asam, D; Spellerberg, B

    2014-08-01

    Streptococcus anginosus and the closely related species Streptococcus constellatus and Streptococcus intermedius, are primarily commensals of the mucosa. The true pathogenic potential of this group has been under-recognized for a long time because of difficulties in correct species identification as well as the commensal nature of these species. In recent years, streptococci of the S. anginosus group have been increasingly found as relevant microbial pathogens in abscesses and blood cultures and they play a pathogenic role in cystic fibrosis. Several international studies have shown a surprisingly high frequency of infections caused by the S. anginosus group. Recent studies and a genome-wide comparative analysis suggested the presence of multiple putative virulence factors that are well-known from other streptococcal species. However, very little is known about the molecular basis of pathogenicity in these bacteria. This review summarizes our current knowledge of pathogenicity factors and their regulation in S. anginosus. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Purification and crystallization of components of the protein-synthesizing system from Thermus thermophilus

    Science.gov (United States)

    Garber, M. B.; Agalarov, S. Ch.; Eliseikina, I. A.; Sedelnikova, S. E.; Tishchenko, S. V.; Shirokov, V. A.; Yusupov, M. M.; Reshetnikova, L. S.; Trakhanov, S. D.; Tukalo, M. A.; Yaremchuk, A. D.

    1991-03-01

    An extreme thermophilic bacterium Thermus thermophilus has been chosen as a source for the isolation of components of the protein-synthesizing system to investigate their structures by X-ray crystallographic methods. The scheme of simultaneous isolation of ribosomes, tRNA, three elongation factors, several aminoacyl-tRNA synthetases and several enzymes has been developed. Methods of purification of ribosomes and individual ribosomal proteins without denaturation were elaborated. Crystals of the elongation factor G, the 70S ribosome, the 30S ribosomal subunit, six ribosomal proteins and three aminoacyl-tRNA synthetases have been obtained. Structural investigations of EF-G and the 70S ribosome are underway.

  6. Streptococcus tangierensis sp. nov. and Streptococcus cameli sp. nov., two novel Streptococcus species isolated from raw camel milk in Morocco.

    Science.gov (United States)

    Kadri, Zaina; Vandamme, Peter; Ouadghiri, Mouna; Cnockaert, Margo; Aerts, Maarten; Elfahime, El Mostafa; Farricha, Omar El; Swings, Jean; Amar, Mohamed

    2015-02-01

    Biochemical and molecular genetic studies were performed on two unidentified Gram-stain positive, catalase and oxidase negative, non-hemolytic Streptococcus-like organisms recovered from raw camel milk in Morocco. Phenotypic characterization and comparative 16S rRNA gene sequencing demonstrated that the two strains were highly different from each other and that they did not correspond to any recognized species of the genus Streptococcus. Phylogenetic analysis based on 16S rRNA gene sequences showed the unidentified organisms each formed a hitherto unknown sub-line within the genus Streptococcus, displaying a close affinity with Streptococcus moroccensis, Streptococcus minor and Streptococcus ovis. DNA G+C content determination, MALDI-TOF mass spectrometry and biochemical tests demonstrated the bacterial isolates represent two novel species. Based on the phenotypic distinctiveness of the new bacteria and molecular genetic evidence, it is proposed to classify the two strains as Streptococcus tangierensis sp. nov., with CCMM B832(T) (=LMG 27683(T)) as the type strain, and Streptococcus cameli sp. nov., with CCMM B834(T) (=LMG 27685(T)) as the type strain.

  7. Antibody binding to Streptococcus mitis and Streptococcus oralis cell fractions.

    Science.gov (United States)

    Wirth, Katherine A; Bowden, George H; Richmond, Dorothy A; Sheridan, Michael J; Cole, Michael F

    2008-02-01

    To determine which cell fraction(s) of Streptococcus mitis biovar 1 serve as the best source of antigens recognized by salivary SIgA antibodies in infants. Whole cells of 38 reference and wild-type isolates of S. mitis, Streptococcus oralis, Streptococcus gordonii, Enterococcus casseliflavus, and Enterococcus faecalis were fractionated into cell walls (CW), protease-treated cell walls (PTCW), cell membranes (CM) and cell protein (CP). Whole cells and these fractions were tested for binding by rabbit anti-S. mitis SK145 and anti-S. oralis SK100 sera, and also by salivary SIgA antibodies from infants and adults. Anti-SK145 and anti-SK100 sera bound whole cells and fractions of all strains of S. mitis and S. oralis variably. Cluster analysis of antibody binding data placed the strains into S. mitis, S. oralis and 'non-S. mitis/non-S. oralis' clusters. Antigens from CW and CM best discriminated S. mitis from S. oralis. CM bound the most infant salivary SIgA antibody and PTCW bound the least. In contrast, adult salivary SIgA antibody bound all of the cell fractions and at higher levels. Presumably the relatively short period of immune stimulation and immunological immaturity in infants, in contrast to adults, result in low levels of salivary SIgA antibody that preferentially bind CM of S. mitis but not PTCW. By utilizing isolated cell walls and membranes as sources of antigens for proteomics it may be possible to identify antigens common to oral streptococci and dissect the fine specificity of salivary SIgA antibodies induced by oral colonization by S. mitis.

  8. Streptococcus salivarius K12 Limits Group B Streptococcus Vaginal Colonization.

    Science.gov (United States)

    Patras, Kathryn A; Wescombe, Philip A; Rösler, Berenice; Hale, John D; Tagg, John R; Doran, Kelly S

    2015-09-01

    Streptococcus agalactiae (group B streptococcus [GBS]) colonizes the rectovaginal tract in 20% to 30% of women and during pregnancy can be transmitted to the newborn, causing severe invasive disease. Current routine screening and antibiotic prophylaxis have fallen short of complete prevention of GBS transmission, and GBS remains a leading cause of neonatal infection. We have investigated the ability of Streptococcus salivarius, a predominant member of the native human oral microbiota, to control GBS colonization. Comparison of the antibacterial activities of multiple S. salivarius strains by use of a deferred-antagonism test showed that S. salivarius strain K12 exhibited the broadest spectrum of activity against GBS. K12 effectively inhibited all GBS strains tested, including disease-implicated isolates from newborns and colonizing isolates from the vaginal tract of pregnant women. Inhibition was dependent on the presence of megaplasmid pSsal-K12, which encodes the bacteriocins salivaricin A and salivaricin B; however, in coculture experiments, GBS growth was impeded by K12 independently of the megaplasmid. We also demonstrated that K12 adheres to and invades human vaginal epithelial cells at levels comparable to GBS. Inhibitory activity of K12 was examined in vivo using a mouse model of GBS vaginal colonization. Mice colonized with GBS were treated vaginally with K12. K12 administration significantly reduced GBS vaginal colonization in comparison to nontreated controls, and this effect was partially dependent on the K12 megaplasmid. Our results suggest that K12 may have potential as a preventative therapy to control GBS vaginal colonization and thereby prevent its transmission to the neonate during pregnancy. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  9. Seeing Streptococcus pneumoniae, a Common Killer Bacteria

    DEFF Research Database (Denmark)

    Kjærgaard, Rikke Schmidt; Andersen, Ebbe Sloth

    2014-01-01

    of the bacteria Streptococcus pneumoniae by use of ink, watercolours and computer graphics. We propose a novel artistic visual rendering of Streptococcus pneumoniae and ask what the value of these kind of representations are compared to traditional scientific data. We ask if drawings and computer...

  10. Epidemiological Significance of the Colonization of Streptococcus ...

    African Journals Online (AJOL)

    Knowledge of Group B Streptococcus (GBS) carriage and infections in Africa is very scanty but few cases have been reported in Nigeria in particular. Streptococcus agalactiae has been reported to cause infections and diseases in non-parturients and adults ranging from bacteremia, osteomylitis, arthritis, and endocarditis to ...

  11. Group A Streptococcus endometritis following medical abortion.

    Science.gov (United States)

    Gendron, Nicolas; Joubrel, Caroline; Nedellec, Sophie; Campagna, Jennifer; Agostini, Aubert; Doucet-Populaire, Florence; Casetta, Anne; Raymond, Josette; Poyart, Claire; Kernéis, Solen

    2014-07-01

    Medical abortion is not recognized as a high-risk factor for invasive pelvic infection. Here, we report two cases of group A Streptococcus (GAS; Streptococcus pyogenes) endometritis following medical abortions with a protocol of oral mifepristone and misoprostol. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  12. (Garlic) and Erythromycin on Streptococcus Pyogenes

    African Journals Online (AJOL)

    Comparative efficacy of garlic and erythromycin on streptococcus pyogenes was carried out in vitro using agar-well diffusion technique. The streptococcus pyogenes used were isolated fromthe conjunctiva of infected patients that visitedAbia StateUniversity,Optometry clinic. The isolated microorganisms were identified and ...

  13. Streptococcus pyogenes toxic-shock syndrome

    OpenAIRE

    Antunes, R.; Diogo, M; Carvalho, A.; Pimentel, T; Oliveira, J.

    2011-01-01

    Recently there has been an exponential increase in invasive infections caused by Streptococcus ß hemolyticcus group A. In about one third of cases they are complicated by toxic shock syndrome, characterized by septic shock and multiorgan failure. The authors, by their rarity, report a case of bacteraemia caused by Streptococcus pyogenes complicated by toxic shock syndrome.

  14. Strategies for improving extracellular lipolytic enzyme production by Thermus thermophilus HB27.

    Science.gov (United States)

    Deive, Francisco J; Carvalho, Elisabete; Pastrana, Lorenzo; Rúa, Maria L; Longo, Maria A; Sanroman, M Angeles

    2009-07-01

    In Thermus thermophilus HB27 cultures the localisation of lipolytic activity is extracellular, intracellular and membrane bound, with low percentage for the former. Therefore, the extracellular secretion must be increased in order to simplify the downstream process and to reduce the economic cost. This study focuses on the design of an innovative operational strategy to increase extracellular lipolytic enzyme production by T. thermophilus HB27 at bioreactor scale. In order to favour its secretion, the effect of several operational variables was evaluated. Among them, the presence of oils in the culture medium leads to improvements in growth and lipolytic enzyme activity. Sunflower oil is the most efficient inducer showing better results when added after 10h of growth. On the other hand, although surfactants lead to an almost complete inhibition of growth and lipolytic enzyme production, their addition along the culture could affect the location of the enzyme. Thus, by addition of surfactants at the stationary phase, a release of intracellular and membrane enzyme which increases the extracellular enzyme proportion is detected. Based on these results, strategies with successive addition of oil and surfactant in several culture phases in shake flask are developed and verified in a laboratory scale stirred tank bioreactor.

  15. Crystallization and preliminary crystallographic analysis of molybdenum-cofactor biosynthesis protein C from Thermus thermophilus

    Energy Technology Data Exchange (ETDEWEB)

    Kanaujia, Shankar Prasad; Ranjani, Chellamuthu Vasuki; Jeyakanthan, Jeyaraman; Baba, Seiki; Chen, Lirong; Liu, Zhi-Jie; Wang, Bi-Cheng; Nishida, Masami; Ebihara, Akio; Shinkai, Akeo; Kuramitsu, Seiki; Shiro, Yoshitsugu; Sekar, Kanagaraj; Yokoyama, Shigeyuki (IIS); (SP8); (Georgia)

    2010-12-03

    The Gram-negative aerobic eubacterium Thermus thermophilus is an extremely important thermophilic microorganism that was originally isolated from a thermal vent environment in Japan. The molybdenum cofactor in this organism is considered to be an essential component required by enzymes that catalyze diverse key reactions in the global metabolism of carbon, nitrogen and sulfur. The molybdenum-cofactor biosynthesis protein C derived from T. thermophilus was crystallized in two different space groups. Crystals obtained using the first crystallization condition belong to the monoclinic space group P2{sub 1}, with unit-cell parameters a = 64.81, b = 109.84, c = 115.19 {angstrom}, {beta} = 104.9{sup o}; the crystal diffracted to a resolution of 1.9 {angstrom}. The other crystal form belonged to space group R32, with unit-cell parameters a = b = 106.57, c = 59.25 {angstrom}, and diffracted to 1.75 {angstrom} resolution. Preliminary calculations reveal that the asymmetric unit contains 12 monomers and one monomer for the crystals belonging to space group P2{sub 1} and R32, respectively.

  16. Metal influence on metallothionein synthesis in the hydrothermal vent mussel Bathymodiolus thermophilus.

    Science.gov (United States)

    Hardivillier, Yann; Denis, Françoise; Demattei, Marie-Véronique; Bustamante, Paco; Laulier, Marc; Cosson, Richard

    2006-07-01

    The present study reports on the metallothionein expression in the hydrothermal vent mussel Bathymodiolus thermophilus. Metallothioneins (MT) are proteins involved in intracellular metal regulation and conserved throughout the animal kingdom. The hydrothermal vent environment presents peculiarities (high levels of sulfides and metals, low pH, anoxia) that may have driven associated species to develop original evolutionary ways to face these extreme living conditions. Mussels were exposed to different metal solutions at the atmospheric pressure. The MT mRNA levels and MT contents were measured in gills and mantles of each exposed mussel. The intracellular metal distribution was estimated in fractions obtained after the centrifugation of tissue homogenates. A few of the tested metals (Ag, Cu, Cd, Hg and Zn) were able to significantly induce MT mRNA levels. Silver was the only one that produced a significant increase of the MT protein level in both mantle and gills. The gills always presented higher MT protein levels than the mantle did, while their MT mRNA levels were similar. Our data show that MT mRNA and MT protein levels do not follow a clear relationship in the gills and mantle of B. thermophilus and we assume that a posttranscriptional control occurs in these mussels.

  17. Complete genome sequence of Hydrogenobacter thermophilus type strain (TK-6T)

    Energy Technology Data Exchange (ETDEWEB)

    Zeytun, Ahmet [Los Alamos National Laboratory (LANL); Sikorski, Johannes [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Nolan, Matt [Joint Genome Institute, Walnut Creek, California; Lapidus, Alla L. [Joint Genome Institute, Walnut Creek, California; Lucas, Susan [Joint Genome Institute, Walnut Creek, California; Han, James [Joint Genome Institute; Tice, Hope [Joint Genome Institute, Walnut Creek, California; Cheng, Jan-Fang [Joint Genome Institute, Walnut Creek, California; Tapia, Roxanne [Los Alamos National Laboratory (LANL); Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Pitluck, Sam [Joint Genome Institute, Walnut Creek, California; Liolios, Konstantinos [Joint Genome Institute, Walnut Creek, California; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Mikhailova, Natalia [U.S. Department of Energy, Joint Genome Institute; Ovchinnikova, Galina [U.S. Department of Energy, Joint Genome Institute; Pati, Amrita [U.S. Department of Energy, Joint Genome Institute; Chen, Amy [Joint Genome Institute, Walnut Creek, California; Palaniappan, Krishna [Joint Genome Institute, Walnut Creek, California; Ngatchou, Olivier Duplex [HZI - Helmholtz Centre for Infection Research, Braunschweig, Germany; Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Chang, Yun-Juan [ORNL; Jeffries, Cynthia [Oak Ridge National Laboratory (ORNL); Han, Cliff [Los Alamos National Laboratory (LANL); Detter, J. Chris [Joint Genome Institute, Walnut Creek, California; Ubler, Susanne [Universitat Regensburg, Regensburg, Germany; Rohde, Manfred [HZI - Helmholtz Centre for Infection Research, Braunschweig, Germany; Tindall, Brian [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Wirth, Reinhard [Universitat Regensburg, Regensburg, Germany; Woyke, Tanja [Joint Genome Institute, Walnut Creek, California; Bristow, James [Joint Genome Institute, Walnut Creek, California; Eisen, Jonathan [Joint Genome Institute, Walnut Creek, California; Markowitz, Victor [Joint Genome Institute, Walnut Creek, California; Hugenholtz, Philip [U.S. Department of Energy, Joint Genome Institute; Klenk, Hans-Peter [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Kyrpides, Nikos C [Joint Genome Institute, Walnut Creek, California

    2011-01-01

    Hydrogenobacter thermophilus Kawasumi et al. 1984 is the type species of the genus Hydrogenobacter. H. thermophilus was the first obligate autotrophic organism reported among aerobic hydrogen-oxidizing bacteria. Strain TK-6T is of interest because of the unusually efficient hydrogen-oxidizing ability of this strain, which results in a faster generation time compared to other autotrophs. It is also able to grow anaerobically using nitrate as an electron acceptor when molecular hydrogen is used as the energy source, and able to aerobically fix CO2 via the reductive tricarboxylic acid cycle. This is the fifth completed genome sequence in the family Aquificaceae, and the second genome sequence determined from a strain derived from the original isolate. Here we describe the features of this organism, together with the complete genome sequence and annotation. The 1,742,932 bp long genome with its 1,899 protein-coding and 49 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

  18. Structure and Activity of the RNA-Targeting Type III-B CRISPR-Cas Complex of Thermus thermophilus

    NARCIS (Netherlands)

    Staals, R.H.J.; Agari, Y.; Maki-Yonekura, S.; Zhu, Y.; Taylor, D.W.; Duijn, van E.; Barendregt, A.; Vlot, M.; Koehorst, J.J.; Sakamoto, K.; Masuda, A.; Dohmae, N.; Schaap, P.J.; Doudna, J.A.; Heck, A.; Yonekura, K.; Oost, van der J.; Shinkai, A.

    2013-01-01

    The CRISPR-Cas system is a prokaryotic host defense system against genetic elements. The Type III-B CRISPR-Cas system of the bacterium Thermus thermophilus, the TtCmr complex, is composed of six different protein subunits (Cmr1-6) and one crRNA with a stoichiometry of Cmr112131445361:crRNA1. The

  19. Structure-based cleavage mechanism of Thermus thermophilus Argonaute DNA guide strand-mediated DNA target cleavage

    NARCIS (Netherlands)

    Sheng, G.; Zhao, H.; Wang, J.; Rao, Y.; Tian, W.; Swarts, D.C.; Oost, van der J.; Patel, D.J.; Wang, Y.

    2014-01-01

    We report on crystal structures of ternary Thermus thermophilus Argonaute (TtAgo) complexes with 5'-phosphorylated guide DNA and a series of DNA targets. These ternary complex structures of cleavage-incompatible, cleavage-compatible, and postcleavage states solved at improved resolution up to 2.2 Å

  20. Streptococcus milleri in the appendix.

    Science.gov (United States)

    Poole, P M; Wilson, G

    1977-01-01

    The appendix was investigated as a possible habitat of Streptococcus milleri. Both normal and inflamed appendices were examined and the isolation rates compared. S. milleri was present in a quarter of the normal appendices and more than half of those associated with apendicitis--a difference that was statistically highly significant. The isolation rates throughout were indepencent of age. There was a pronounced connection between the presence of S. milleri in the appendix and the purulent manifestations of appendicitis. S. milleri was isolated from other abdominal sites associated with appendicitis. The frequency of isolation was increased by culture in an enrichment broth containing nalidixic acid and sulphadimidine. PMID:591633

  1. Streptococcus intermedius, Streptococcus constellatus, and Streptococcus anginosus (the Streptococcus milleri group): association with different body sites and clinical infections.

    Science.gov (United States)

    Whiley, R A; Beighton, D; Winstanley, T G; Fraser, H Y; Hardie, J M

    1992-01-01

    The associations of Streptococcus intermedius, S. constellatus, and S. anginosus (the three species of the S. milleri group) with clinical infections and sites of isolation were investigated by using a simple biochemical scheme to identify a collection of 153 clinical isolates. S. intermedius was associated with abscesses of the brain and liver, while both S. anginosus and S. constellatus were isolated from a wider range of sites and infections. S. anginosus strains predominated in both genitourinary and gastrointestinal sources and exhibited a wider range of phenotypes, particularly in the ability to ferment mannitol and/or raffinose. PMID:1734062

  2. Streptococcus milleri in the appendix.

    Science.gov (United States)

    Poole, P M; Wilson, G

    1977-10-01

    The appendix was investigated as a possible habitat of Streptococcus milleri. Both normal and inflamed appendices were examined and the isolation rates compared. S. milleri was present in a quarter of the normal appendices and more than half of those associated with apendicitis--a difference that was statistically highly significant. The isolation rates throughout were indepencent of age. There was a pronounced connection between the presence of S. milleri in the appendix and the purulent manifestations of appendicitis. S. milleri was isolated from other abdominal sites associated with appendicitis. The frequency of isolation was increased by culture in an enrichment broth containing nalidixic acid and sulphadimidine.

  3. Detection of Streptococcus pneumoniae DNA in blood cultures by PCR.

    OpenAIRE

    Hassan-King, M; Baldeh, I; Secka, O; Falade, A; Greenwood, B

    1994-01-01

    We have developed a PCR assay, with primers derived from the autolysin (lyt) gene, for the detection of Streptococcus pneumoniae DNA in blood cultures. The predicted fragment of 247 bp was detected in all strains of pneumococci, embracing 12 different serotypes that were tested. Although DNA extracted from four viridans streptococci spp. Streptococcus oralis, Streptococcus mitis, Streptococcus sanguis, and Streptococcus parasanguis) gave amplification products, these were quite different from...

  4. Prospective study of Streptococcus milleri hepatic abscess.

    Science.gov (United States)

    Corredoira, J; Casariego, E; Moreno, C; Villanueva, L; López; Varela, J; Rodríguez, A; Alonso, P; Coira, A

    1998-08-01

    Thirty-seven cases of microbiologically demonstrated pyogenic hepatic abscess were observed in a prospective study over a seven-year period. Biliary disease was the most common source of liver abscess (42%). Streptococcus milleri was the most common cause of hepatic abscess, accounting for 51% of the cases. Hepatic abscess is due to Streptococcus milleri clinically distinct from other forms of pyogenic liver abscess due to its torpid nature and the longer duration of its symptoms [42 vs. 11 days]. Occult hepatic abscess should be suspected if the blood culture is positive for Streptococcus milleri, since 28% of bacteremia cases due to Streptococcus milleri stem from hepatic abscesses. It is important to distinguish Streptococcus milleri from other members of the viridans streptococci group, which are frequently isolated as contaminants, but only exceptionally cause hepatic abscess. Unlike other pyogenic hepatic abscesses, those caused by Streptococcus milleri are frequently monomicrobial (79%). In the present study, empirical therapy of pyogenic hepatic abscess always included a drug that is effective against Streptococcus milleri.

  5. Transformation of Streptococcus sanguis Challis with Streptococcus lactis plasmid DNA.

    Science.gov (United States)

    Harlander, S K; McKay, L L

    1984-01-01

    Streptococcus lactis plasmid DNA, which is required for the fermentation of lactose (plasmid pLM2001), and a potential streptococcal cloning vector plasmid (pDB101) which confers resistance to erythromycin were evaluated by transformation into Streptococcus sanguis Challis. Plasmid pLM2001 transformed lactose-negative (Lac-) mutants of S. sanguis with high efficiency and was capable of conferring lactose-metabolizing ability to a mutant deficient in Enzyme IIlac, Factor IIIlac, and phospho-beta-galactosidase of the lactose phosphoenolpyruvate-phosphotransferase system. Plasmid pDB101 was capable of high-efficiency transformation of S. sanguis to antibiotic resistance, and the plasmid could be readily isolated from transformed strains. However, when 20 pLM2001 Lac+ transformants were analyzed by a variety of techniques for the presence of plasmids, none could be detected. In addition, attempts to cure the Lac+ transformants by treatment with acriflavin were unsuccessful. Polyacrylamide gel electrophoresis was used to demonstrate that the transformants had acquired a phospho-beta-galactosidase characteristic of that normally produced by S. lactis and not S. sanguis. It is proposed that the genes required for lactose fermentation may have become stabilized in the transformants due to their integration into the host chromosome. The efficient transformation into and expression of pLM2001 and pDB101 genes in S. sanguis provides a model system which could allow the development of a system for cloning genes from dairy starter cultures into S. sanguis to examine factors affecting their expression and regulation. Images PMID:6435522

  6. Capsular Polysaccharide Expression in Commensal Streptococcus Species: Genetic and Antigenic Similarities to Streptococcus pneumoniae

    National Research Council Canada - National Science Library

    Skov Sørensen, Uffe B; Yao, Kaihu; Yang, Yonghong; Tettelin, Hervé; Kilian, Mogens

    2016-01-01

    Expression of a capsular polysaccharide is considered a hallmark of most invasive species of bacteria, including Streptococcus pneumoniae, in which the capsule is among the principal virulence factors...

  7. The structure of the peripheral stalk of Thermus thermophilus H+-ATPase/synthase

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Lawrence K; Stewart, Alastair G; Donohoe, Mhairi; Bernal, Ricardo A; Stock, Daniela (VCCRI); (New South); (Texas)

    2010-03-22

    Proton-translocating ATPases are ubiquitous protein complexes that couple ATP catalysis with proton translocation via a rotary catalytic mechanism. The peripheral stalks are essential components that counteract torque generated from proton translocation during ATP synthesis or from ATP hydrolysis during proton pumping. Despite their essential role, the peripheral stalks are the least conserved component of the complexes, differing substantially between subtypes in composition and stoichiometry. We have determined the crystal structure of the peripheral stalk of the A-type ATPase/synthase from Thermus thermophilus consisting of subunits E and G. The structure contains a heterodimeric right-handed coiled coil, a protein fold never observed before. We have fitted this structure into the 23 {angstrom} resolution EM density of the intact A-ATPase complex, revealing the precise location of the peripheral stalk and new implications for the function and assembly of proton-translocating ATPases.

  8. Cryo EM structure of intact rotary H+-ATPase/synthase from Thermus thermophilus.

    Science.gov (United States)

    Nakanishi, Atsuko; Kishikawa, Jun-Ichi; Tamakoshi, Masatada; Mitsuoka, Kaoru; Yokoyama, Ken

    2018-01-08

    Proton translocating rotary ATPases couple ATP hydrolysis/synthesis, which occurs in the soluble domain, with proton flow through the membrane domain via a rotation of the common central rotor complex against the surrounding peripheral stator apparatus. Here, we present a large data set of single particle cryo-electron micrograph images of the V/A type H+-rotary ATPase from the bacterium Thermus thermophilus, enabling the identification of three rotational states based on the orientation of the rotor subunit. Using masked refinement and classification with signal subtractions, we obtain homogeneous reconstructions for the whole complexes and soluble V1 domains. These reconstructions are of higher resolution than any EM map of intact rotary ATPase reported previously, providing a detailed molecular basis for how the rotary ATPase maintains structural integrity of the peripheral stator apparatus, and confirming the existence of a clear proton translocation path from both sides of the membrane.

  9. Kinetics and product analysis of the reaction catalysed by recombinant homoaconitase from Thermus thermophilus.

    Science.gov (United States)

    Jia, Yunhua; Tomita, Takeo; Yamauchi, Kazuma; Nishiyama, Makoto; Palmer, David R J

    2006-06-15

    HACN (homoaconitase) is a member of a family of [4Fe-4S] cluster-dependent enzymes that catalyse hydration/dehydration reactions. The best characterized example of this family is the ubiquitous ACN (aconitase), which catalyses the dehydration of citrate to cis-aconitate, and the subsequent hydration of cis-aconitate to isocitrate. HACN is an enzyme from the alpha-aminoadipate pathway of lysine biosynthesis, and has been identified in higher fungi and several archaea and one thermophilic species of bacteria, Thermus thermophilus. HACN catalyses the hydration of cis-homoaconitate to (2R,3S)-homoisocitrate, but the HACN-catalysed dehydration of (R)-homocitrate to cis-homoaconitate has not been observed in vitro. We have synthesized the substrates and putative substrates for this enzyme, and in the present study report the first steady-state kinetic data for recombinant HACN from T. thermophilus using a (2R,3S)-homoisocitrate dehydrogenase-coupled assay. We have also examined the products of the reaction using HPLC. We do not observe HACN-catalysed 'homocitrate dehydratase' activity; however, we have observed that ACN can catalyse the dehydration of (R)-homocitrate to cis-homoaconitate, but HACN is required for subsequent conversion of cis-homoaconitate into homoisocitrate. This suggests that the in vivo process for conversion of homocitrate into homoisocitrate requires two enzymes, in simile with the propionate utilization pathway from Escherichia coli. Surprisingly, HACN does not show any activity when cis-aconitate is substituted for the substrate, even though other enzymes from the alpha-aminoadipate pathway can accept analogous tricarboxylic acid-cycle substrates. The enzyme shows no apparent feedback inhibition by L-lysine.

  10. A novel arsenate reductase from the bacterium Thermus thermophilus HB27: its role in arsenic detoxification.

    Science.gov (United States)

    Del Giudice, Immacolata; Limauro, Danila; Pedone, Emilia; Bartolucci, Simonetta; Fiorentino, Gabriella

    2013-10-01

    Microorganisms living in arsenic-rich geothermal environments act on arsenic with different biochemical strategies, but the molecular mechanisms responsible for the resistance to the harmful effects of the metalloid have only partially been examined. In this study, we investigated the mechanisms of arsenic resistance in the thermophilic bacterium Thermus thermophilus HB27. This strain, originally isolated from a Japanese hot spring, exhibited tolerance to concentrations of arsenate and arsenite up to 20mM and 15mM, respectively; it owns in its genome a putative chromosomal arsenate reductase (TtarsC) gene encoding a protein homologous to the one well characterized from the plasmid pI258 of the Gram+bacterium Staphylococcus aureus. Differently from the majority of microorganisms, TtarsC is part of an operon including genes not related to arsenic resistance; qRT-PCR showed that its expression was four-fold increased when arsenate was added to the growth medium. The gene cloning and expression in Escherichia coli, followed by purification of the recombinant protein, proved that TtArsC was indeed a thioredoxin-coupled arsenate reductase with a kcat/KM value of 1.2×10(4)M(-1)s(-1). It also exhibited weak phosphatase activity with a kcat/KM value of 2.7×10(-4)M(-1)s(-1). The catalytic role of the first cysteine (Cys7) was ascertained by site-directed mutagenesis. These results identify TtArsC as an important component in the arsenic resistance in T. thermophilus giving the first structural-functional characterization of a thermophilic arsenate reductase. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Functional dissection of the multi-domain di-heme cytochrome c(550 from Thermus thermophilus.

    Directory of Open Access Journals (Sweden)

    Sylvain Robin

    Full Text Available In bacteria, oxidation of sulfite to sulfate, the most common strategy for sulfite detoxification, is mainly accomplished by the molybdenum-containing sulfite:acceptor oxidoreductases (SORs. Bacterial SORs are very diverse proteins; they can exist as monomers or homodimers of their core subunit, as well as heterodimers with an additional cytochrome c subunit. We have previously described the homodimeric SOR from Thermus thermophilus HB8 (SOR(TTHB8, identified its physiological electron acceptor, cytochrome c(550, and demonstrated the key role of the latter in coupling sulfite oxidation to aerobic respiration. Herein, the role of this di-heme cytochrome c was further investigated. The cytochrome was shown to be composed of two conformationally independent domains, each containing one heme moiety. Each domain was separately cloned, expressed in E. coli and purified to homogeneity. Stopped-flow experiments showed that: i the N-terminal domain is the only one accepting electrons from SOR(TTHB8; ii the N- and C-terminal domains are in rapid redox equilibrium and iii both domains are able to transfer electrons further to cytochrome c(552, the physiological substrate of the ba(3 and caa(3 terminal oxidases. These findings show that cytochrome c(550 functions as a electron shuttle, without working as an electron wire with one heme acting as the electron entry and the other as the electron exit site. Although contribution of the cytochrome c(550 C-terminal domain to T. thermophilus sulfur respiration seems to be dispensable, we suggest that di-heme composition of the cytochrome physiologically enables storage of the two electrons generated from sulfite oxidation, thereof ensuring efficient contribution of sulfite detoxification to the respiratory chain-mediated energy generation.

  12. Streptococcus pyogenes in Human Plasma

    Science.gov (United States)

    Malmström, Johan; Karlsson, Christofer; Nordenfelt, Pontus; Ossola, Reto; Weisser, Hendrik; Quandt, Andreas; Hansson, Karin; Aebersold, Ruedi; Malmström, Lars; Björck, Lars

    2012-01-01

    Streptococcus pyogenes is a major bacterial pathogen and a potent inducer of inflammation causing plasma leakage at the site of infection. A combination of label-free quantitative mass spectrometry-based proteomics strategies were used to measure how the intracellular proteome homeostasis of S. pyogenes is influenced by the presence of human plasma, identifying and quantifying 842 proteins. In plasma the bacterium modifies its production of 213 proteins, and the most pronounced change was the complete down-regulation of proteins required for fatty acid biosynthesis. Fatty acids are transported by albumin (HSA) in plasma. S. pyogenes expresses HSA-binding surface proteins, and HSA carrying fatty acids reduced the amount of fatty acid biosynthesis proteins to the same extent as plasma. The results clarify the function of HSA-binding proteins in S. pyogenes and underline the power of the quantitative mass spectrometry strategy used here to investigate bacterial adaptation to a given environment. PMID:22117078

  13. Streptococcus pneumoniae and the host cell

    NARCIS (Netherlands)

    Gradstedt, Per Henrik

    2012-01-01

    Streptococcus pneumoniae is een bacterie die in de menselijke keel-neusholte voorkomt. Vaak is zij ongevaarlijk, maar soms kan zij van leefomgeving veranderen en zich als invasieve ziekteverwekker door het lichaam verspreiden. Dan kan de bacterie longontsteking, bloedvergiftiging of

  14. Detection and quantification of Streptococcus pneumoniae from ...

    African Journals Online (AJOL)

    Jane

    2011-10-05

    Oct 5, 2011 ... detection of Streptococcus pneumoniae from clinical respiratory specimens. Initially, 184 respiratory specimens .... ventional bacteriological techniques. Therefore, this is ..... Manual of Clinical Microbiology.9th ed. ASM press.

  15. Role of Streptococcus Anginosus on the formation of dental caries

    Directory of Open Access Journals (Sweden)

    Yetty Herdiyati Nonong

    2011-11-01

    Full Text Available Generally, the etiology of dental caries is the cariogenic properties of bacteria, these are always associated with Streptococcus mutans. Glucosyltransferase fragment (Gtf are also in other strains of Streptococcus such as Streptococcus anginosus, Streptococcus milleri which includes beta hemolysis. Genotypically B Streptococcus anginosus has genetic characteristics that are similar to Streptococcus mutans. The research objective was to determine the existence of Gtf B/C gene as a cause of caries in Streptococcus anginosus. The study was conducted in experimental laboratories with PCR technique by taking a sample of 20 children who had caries. The results showed there was the amplification of Streptococcus anginosus with a level of homology 96%, 97%, and 99%. The results of the Gtf genes amplification fragment B/C provided 600 pb ribbon. The conclusion was Streptococcus anginosus classified as cariogenic bacteria because they had Gtf B/C genes.

  16. Transformation and fusion of Streptococcus faecalis protoplasts.

    OpenAIRE

    Smith, M. D.

    1985-01-01

    Nonconjugative plasmids were transferred by protoplast fusion among Streptococcus faecalis strains and from Streptococcus sanguis to S. faecalis. S. faecalis protoplasts were also transformed with several different plasmids, including the Tn917 delivery vehicle pTV1. Transformation was reproducible, but low in frequency (10(-6) transformants per viable protoplast). A new shuttle vector (pAM610), able to replicate in Escherichia coli and S. faecalis, was constructed and transformed into S. fae...

  17. Streptococcus sanguis endocarditis associated with colonic carcinoma.

    Science.gov (United States)

    Nijjer, Sukhjinder; Dubrey, Simon William

    2010-01-01

    Infective endocarditis caused by Streptococcus bovis is known to be associated with colorectal malignancy. Other less common streptococci, specifically Streptococcus sanguis, can be similarly associated with gastrointestinal carcinoma. We present a case of disseminated colorectal carcinoma occurring after a confirmed S sanguis endocarditis, that required mitral valve surgery. There may be a need for gastrointestinal surveillance in patients presenting with bacteraemia caused by less common streptococci.

  18. Population diversity and dynamics of Streptococcus mitis, Streptococcus oralis, and Streptococcus infantis in the upper respiratory tracts of adults, determined by a nonculture strategy

    DEFF Research Database (Denmark)

    Bek-Thomsen, Malene; Tettelin, H; Hance, I

    2008-01-01

    We reinvestigated the clonal diversity and dynamics of Streptococcus mitis and two other abundant members of the commensal microbiota of the upper respiratory tract, Streptococcus oralis and Streptococcus infantis, to obtain information about the origin of frequently emerging clones in this habitat...

  19. Recommended conservation of the names Streptococcus sanguis, Streptococcus rattus, Streptococcus cricetus, and seven other names included in the Approved Lists of Bacterial Names. Request for an opinion.

    Science.gov (United States)

    Kilian, M

    2001-03-01

    With reference to the first Principle of the International Code of Nomenclature of Bacteria, which emphasizes stability of names, it is proposed that the original names Streptococcus sanguis, Streptococcus rattus, Streptococcus cricetus, Erwinia ananas, Eubacterium tarantellus, Lactobacillus sake, Nitrosococcus oceanus, Pseudomonas betle, Rickettsia canada and Streptomyces rangoon, all included in the Approved Lists of Bacterial Names, be conserved. Request for an Opinion.

  20. The effect of mango and neem extract on four organisms causing dental caries: Streptococcus mutans, Streptococcus salivavius, Streptococcus mitis, and Streptococcus sanguis: an in vitro study.

    Science.gov (United States)

    Prashant, G M; Chandu, G N; Murulikrishna, K S; Shafiulla, M D

    2007-01-01

    Chewing twigs of the mango or neem tree is a common way of cleaning the teeth in the rural and semi-urban population. These twigs are also believed to possess medicinal properties. The present study was conducted to evaluate the antimicrobial effects of these chewing sticks on the microorganisms Streptococcus mutans , Streptococcus salivarius , Streptococcus mitis , and Streptococcus sanguis which are involved in the development of dental caries. An additional objective was to identify an inexpensive, simple, and effective method of preventing and controlling dental caries. The sticks were sun dried, ground into a coarse powder, and weighed into 5 gm, 10 gm, and 50 gm amounts. These were added to 100 ml of deionized distilled water. After soaking for 48 h at 4 degrees C, the water was filtered. The filtrate was inoculated onto blood agar plates containing individual species of microorganisms and incubated at 37 degrees C for 48 h. Mango extract, at 50% concentration, showed maximum zone of inhibition on Streptococcus mitis . Neem extract produced the maximum zone of inhibition on Streptococcus mutans at 50% concentration. Even at 5% concentration neem extract showed some inhibition of growth for all the four species of organisms. A combination of neem and mango chewing sticks may provide the maximum benefit. We recommend the use of both the chewing sticks.

  1. The effect of mango and neem extract on four organisms causing dental caries: Streptococcus mutans, Streptococcus salivavius, Streptococcus mitis, and Streptococcus sanguis: An in vitro study

    Directory of Open Access Journals (Sweden)

    Prashant G

    2007-01-01

    Full Text Available Background and Objectives: Chewing twigs of the mango or neem tree is a common way of cleaning the teeth in the rural and semi-urban population. These twigs are also believed to possess medicinal properties. The present study was conducted to evaluate the antimicrobial effects of these chewing sticks on the microorganisms Streptococcus mutans , Streptococcus salivarius , Streptococcus mitis , and Streptococcus sanguis which are involved in the development of dental caries. An additional objective was to identify an inexpensive, simple, and effective method of preventing and controlling dental caries. Materials and Methods: The sticks were sun dried, ground into a coarse powder, and weighed into 5 gm, 10 gm, and 50 gm amounts. These were added to 100 ml of deionized distilled water. After soaking for 48 h at 4°C, the water was filtered. The filtrate was inoculated onto blood agar plates containing individual species of microorganisms and incubated at 37°C for 48 h. Results: Mango extract, at 50% concentration, showed maximum zone of inhibition on Streptococcus mitis . Neem extract produced the maximum zone of inhibition on Streptococcus mutans at 50% concentration. Even at 5% concentration neem extract showed some inhibition of growth for all the four species of organisms. Interpretation and Conclusion: A combination of neem and mango chewing sticks may provide the maximum benefit. We recommend the use of both the chewing sticks.

  2. Identification and molecular modeling of a family 5 endocellulase from Thermus caldophilus GK24, a cellulolytic strain of Thermus thermophilus

    Directory of Open Access Journals (Sweden)

    Dae-Sil Lee

    2006-12-01

    Full Text Available The genome of T. caldophilus GK24 was recently sequenced and annotated as 14contigs, equivalent to 2.3 mega basepairs (Mbp of DNA. In the current study, we identifieda unique 13.7 kbp DNA sequence, which included the endocellulase gene of T. caldophilusGK24, which did not appear to be present in the complete genomic sequence of the closelyrelated species T. thermophilus HB27 and HB8. Congo-red staining revealed a uniquephenotype of cellulose degradation by strain GK24 that was distinct from other closelyrelated Thermus strains. The results showed that strain GK24 is an aerobic, thermophilic,cellulolytic eubacterium which belongs to the group T. thermophilus. In order to understandthe mechanism of production of cellobiose in T. caldophilus GK24, a three-dimensionalmodel of the endocellulase, TcCel5A, was generated based on known crystal structures.Using this model, we carried out a flexible cellotetraose docking study.

  3. Penetration of Streptococcus sobrinus and Streptococcus sanguinis into dental enamel.

    Science.gov (United States)

    Kneist, Susanne; Nietzsche, Sandor; Küpper, Harald; Raser, Gerhard; Willershausen, Brita; Callaway, Angelika

    2015-10-01

    The aim of this pilot study was to assess the difference in virulence of acidogenic and aciduric oral streptococci in an in vitro caries model using their penetration depths into dental enamel. 30 caries-free extracted molars from 11- to 16-year-olds were cleaned ultrasonically for 1 min with de-ionized water and, after air-drying, embedded in epoxy resin. After 8-h of setting at room temperature, the specimens were ground on the buccal side with SiC-paper 1200 (particle size 13-16 μm). Enamel was removed in circular areas sized 3 mm in diameter; the mean depth of removed enamel was 230 ± 60 μm. 15 specimens each were incubated anaerobically under standardized conditions with 24 h-cultures of Streptococcus sanguinis 9S or Streptococcus sobrinus OMZ 176 in Balmelli broth at 37 ± 2 °C; the pH-values of the broths were measured at the beginning and end of each incubation cycle. After 2, 4, 6, 8, and 10 weeks 3 teeth each were fixed in 2.5% glutaraldehyde in cacodylate buffer for 24 h, washed 3× and dehydrated 30-60min by sequential washes through a series of 30-100% graded ethanol. The teeth were cut in half longitudinally; afterward, two slits were made to obtain fracture surfaces in the infected area. After critical-point-drying the fragments were gold-sputtered and viewed in a scanning electron microscope at magnifications of ×20-20,000. After 10 weeks of incubation, penetration of S. sanguinis of 11.13 ± 24.04 μm below the break edges into the enamel was observed. The invasion of S. sobrinus reached depths of 87.53 ± 76.34 μm. The difference was statistically significant (paired t test: p = 0.033). The experimental penetration depths emphasize the importance of S. sanguinis versus S. sobrinus in the context of the extended ecological plaque hypothesis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Isolation of Streptococcus tigurinus - a novel member of Streptococcus mitis group from a case of periodontitis.

    Science.gov (United States)

    Dhotre, Shree V; Mehetre, Gajanan T; Dharne, Mahesh S; Suryawanshi, Namdev M; Nagoba, Basavraj S

    2014-08-01

    Streptococcus tigurinus is a new member of the Streptococcus viridians group and is closely related to Streptococcus mitis, Streptococcus pneumoniae, Streptococcus pseudopneumoniae, Streptococcus oralis, and Streptococcus infantis. The type strain AZ_3a(T) of S. tigurinus was originally isolated from a patient with infective endocarditis. Accurate identification of S. tigurinus is facilitated only by newer molecular methods like 16S rRNA gene analysis. During the course of study on bacteraemia and infective endocarditis with reference to periodontitis and viridians group of streptococci, a strain of S. tigurinus isolated from subgingival plaque of a patient with periodontitis identified by 16S rRNA gene analysis, which was originally identified as Streptococcus pluranimalium by Vitek 2. Confirmation by 16S rRNA gene analysis showed 99.39% similarity (1476/1485 bp) with S. tigurinus AZ_3a(T) (AORU01000002). To the best of our knowledge, this is the first report of isolation of S. tigurinus from the oral cavity of a periodontitis patient. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  5. Functional variation of the antigen I/II surface protein in Streptococcus mutans and Streptococcus intermedius

    NARCIS (Netherlands)

    Petersen, FC; Assev, S; van der Mei, HC; Busscher, HJ; Scheie, AA

    Although Streptococcus intermedius and Streptococcus mutans are regarded as members of the commensal microflora of the body, S. intermedius is often associated with deep-seated purulent infections, whereas S. mutans is frequently associated with dental caries. In this study, we investigated the

  6. Comparison of transmission dynamics between Streptococcus uberis and Streptococcus agalactiae intramammary infections

    NARCIS (Netherlands)

    Leelahapongsathon, Kansuda; Schukken, Ynte Hein; Pinyopummintr, Tanu; Suriyasathaporn, Witaya

    2016-01-01

    The objectives of study were to determine the transmission parameters (β), durations of infection, and basic reproductive numbers (R0) of both Streptococcus agalactiae and Streptococcus uberis as pathogens causing mastitis outbreaks in dairy herds. A 10-mo longitudinal study was performed using 2

  7. Omp85Tt from Thermus thermophilus HB27 : an Ancestral Type of the Omp85 Protein Family

    OpenAIRE

    Nesper, Jutta; Brosig, Alexander; Ringler, Philippe; Patel, Geetika J.; Müller, Shirley A.; Kleinschmidt, Jörg; Boos, Winfried; Diederichs, Kay; Welte, Wolfram

    2008-01-01

    Proteins belonging to the Omp85 family are involved in the assembly of β-barrel outer membrane proteins or in the translocation of proteins across the outer membrane in bacteria, mitochondria, and chloroplasts. The cell envelope of the thermophilic bacterium Thermus thermophilus HB27 is multilayered, including an outer membrane that is not well characterized. Neither the precise lipid composition nor much about integral membrane proteins is known. The genome of HB27 encodes one Omp85-like pro...

  8. A novel approach to crystallizing proteins with temperature-induction method: GrpE protein from Thermus thermophilus

    Science.gov (United States)

    Kitano, Ken; Motohashi, Ken; Yoshida, Masasuke; Miki, Kunio

    1998-03-01

    GrpE protein from Thermus thermophilus has been crystallized by the use of both 2-methyl-2,4-pentanediol and acetic acid as precipitants. It was found that heat treatment at 40°C was indispensable to obtain single crystals of this protein. Here we report one of the most typical examples of the effective temperature induction method in protein crystallization. In this case, no crystals were obtained if the heat treatment was not employed.

  9. A non-radioactive assay for selenophosphate synthetase activity using recombinant pyruvate pyrophosphate dikinase from Thermus thermophilus HB8.

    Science.gov (United States)

    Kamada, Saho; Okugochi, Takahiro; Asano, Kaori; Tobe, Ryuta; Mihara, Hisaaki; Nemoto, Michiko; Inagaki, Kenji; Tamura, Takashi

    2016-10-01

    Biosynthesis of selenocysteine-containing proteins requires monoselenophosphate, a selenium-donor intermediate generated by selenophosphate synthetase (Sephs). A non-radioactive assay was developed as an alternative to the standard [8-(14)C] AMP-quantifying assay. The product, AMP, was measured using a recombinant pyruvate pyrophosphate dikinase from Thermus thermophilus HB8. The KM and kcat for Sephs2-Sec60Cys were determined to be 26 μM and 0.352 min(-1), respectively.

  10. The role of the PHP domain associated with DNA polymerase X from Thermus thermophilus HB8 in base excision repair.

    Science.gov (United States)

    Nakane, Shuhei; Nakagawa, Noriko; Kuramitsu, Seiki; Masui, Ryoji

    2012-11-01

    Base excision repair (BER) is one of the most commonly used DNA repair pathways involved in genome stability. X-family DNA polymerases (PolXs) play critical roles in BER, especially in filling single-nucleotide gaps. In addition to a polymerase core domain, bacterial PolXs have a polymerase and histidinol phosphatase (PHP) domain with phosphoesterase activity which is also required for BER. However, the role of the PHP domain of PolX in bacterial BER remains unresolved. We found that the PHP domain of Thermus thermophilus HB8 PolX (ttPolX) functions as two types of phosphoesterase in BER, including a 3'-phosphatase and an apurinic/apyrimidinic (AP) endonuclease. Experiments using T. thermophilus HB8 cell lysates revealed that the majority of the 3'-phosphatase and AP endonuclease activities are attributable to the another phosphoesterase in T. thermophilus HB8, endonuclease IV (ttEndoIV). However, ttPolX possesses significant 3'-phosphatase activity in ΔttendoIV cell lysate, indicating possible complementation. Our experiments also reveal that there are only two enzymes that display the 3'-phosphatase activity in the T. thermophilus HB8 cell, ttPolX and ttEndoIV. Furthermore, phenotypic analysis of ΔttpolX, ΔttendoIV, and ΔttpolX/ΔttendoIV using hydrogen peroxide and sodium nitrite supports the hypothesis that ttPolX functions as a backup for ttEndoIV in BER. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Molecular and physiological role of the trehalose-hydrolyzing alpha-glucosidase from Thermus thermophilus HB27.

    Science.gov (United States)

    Alarico, Susana; da Costa, Milton S; Empadinhas, Nuno

    2008-04-01

    Trehalose supports the growth of Thermus thermophilus strain HB27, but the absence of obvious genes for the hydrolysis of this disaccharide in the genome led us to search for enzymes for such a purpose. We expressed a putative alpha-glucosidase gene (TTC0107), characterized the recombinant enzyme, and found that the preferred substrate was alpha,alpha-1,1-trehalose, a new feature among alpha-glucosidases. The enzyme could also hydrolyze the disaccharides kojibiose and sucrose (alpha-1,2 linkage), nigerose and turanose (alpha-1,3), leucrose (alpha-1,5), isomaltose and palatinose (alpha-1,6), and maltose (alpha-1,4) to a lesser extent. Trehalose was not, however, a substrate for the highly homologous alpha-glucosidase from T. thermophilus strain GK24. The reciprocal replacement of a peptide containing eight amino acids in the alpha-glucosidases from strains HB27 (LGEHNLPP) and GK24 (EPTAYHTL) reduced the ability of the former to hydrolyze trehalose and provided trehalose-hydrolytic activity to the latter, showing that LGEHNLPP is necessary for trehalose recognition. Furthermore, disruption of the alpha-glucosidase gene significantly affected the growth of T. thermophilus HB27 in minimal medium supplemented with trehalose, isomaltose, sucrose, or palatinose, to a lesser extent with maltose, but not with cellobiose (not a substrate for the alpha-glucosidase), indicating that the alpha-glucosidase is important for the assimilation of those four disaccharides but that it is also implicated in maltose catabolism.

  12. Molecular and Physiological Role of the Trehalose-Hydrolyzing α-Glucosidase from Thermus thermophilus HB27▿ †

    Science.gov (United States)

    Alarico, Susana; da Costa, Milton S.; Empadinhas, Nuno

    2008-01-01

    Trehalose supports the growth of Thermus thermophilus strain HB27, but the absence of obvious genes for the hydrolysis of this disaccharide in the genome led us to search for enzymes for such a purpose. We expressed a putative α-glucosidase gene (TTC0107), characterized the recombinant enzyme, and found that the preferred substrate was α,α-1,1-trehalose, a new feature among α-glucosidases. The enzyme could also hydrolyze the disaccharides kojibiose and sucrose (α-1,2 linkage), nigerose and turanose (α-1,3), leucrose (α-1,5), isomaltose and palatinose (α-1,6), and maltose (α-1,4) to a lesser extent. Trehalose was not, however, a substrate for the highly homologous α-glucosidase from T. thermophilus strain GK24. The reciprocal replacement of a peptide containing eight amino acids in the α-glucosidases from strains HB27 (LGEHNLPP) and GK24 (EPTAYHTL) reduced the ability of the former to hydrolyze trehalose and provided trehalose-hydrolytic activity to the latter, showing that LGEHNLPP is necessary for trehalose recognition. Furthermore, disruption of the α-glucosidase gene significantly affected the growth of T. thermophilus HB27 in minimal medium supplemented with trehalose, isomaltose, sucrose, or palatinose, to a lesser extent with maltose, but not with cellobiose (not a substrate for the α-glucosidase), indicating that the α-glucosidase is important for the assimilation of those four disaccharides but that it is also implicated in maltose catabolism. PMID:18223075

  13. Identification of a VapBC toxin-antitoxin system in a thermophilic bacterium Thermus thermophilus HB27.

    Science.gov (United States)

    Fan, Yuqi; Hoshino, Takayuki; Nakamura, Akira

    2017-01-01

    There are 12 putative toxin-antitoxin (TA) loci in the Thermus thermophilus HB27 genome, including four VapBC and three HicBA families. Expression of these seven putative toxin genes in Escherichia coli demonstrated that one putative VapC toxin TTC0125 and two putative HicA toxins, TTC1395 and TTC1705, inhibited cell growth, and co-expression with cognate antitoxin genes rescued growth, indicating that these genes function as TA loci. In vitro analysis with the purified TTC0125 and total RNA/mRNA from E. coli and T. thermophilus showed that TTC0125 has RNase activity to rRNA and mRNA; this activity was inhibited by the addition of the purified TTC0126. Translation inhibition assays showed that TTC0125 inhibited protein synthesis by degrading mRNA but not by inactivating ribosomes. Amino acid substitutions of 14 predicted catalytic and conserved residues in VapC toxins to Ala or Asp in TTC0125 indicated that nine residues are important for its in vivo toxin activity and in vitro RNase activity. These data demonstrate that TTC0125-TTC0126 functions as a VapBC TA module and causes growth inhibition by degrading free RNA. This is the first study to identify the function of TA systems in T. thermophilus.

  14. Thermus oshimai JL-2 and T. thermophilus JL-18 genome analysis illuminates pathways for carbon, nitrogen, and sulfur cycling

    Science.gov (United States)

    Murugapiran, Senthil K.; Huntemann, Marcel; Wei, Chia-Lin; Han, James; Detter, J. C.; Han, Cliff; Erkkila, Tracy H.; Teshima, Hazuki; Chen, Amy; Kyrpides, Nikos; Mavrommatis, Konstantinos; Markowitz, Victor; Szeto, Ernest; Ivanova, Natalia; Pagani, Ioanna; Pati, Amrita; Goodwin, Lynne; Peters, Lin; Pitluck, Sam; Lam, Jenny; McDonald, Austin I.; Dodsworth, Jeremy A.; Woyke, Tanja; Hedlund, Brian P.

    2013-01-01

    The complete genomes of Thermus oshimai JL-2 and T. thermophilus JL-18 each consist of a circular chromosome, 2.07 Mb and 1.9 Mb, respectively, and two plasmids ranging from 0.27 Mb to 57.2 kb. Comparison of the T. thermophilus JL-18 chromosome with those from other strains of T. thermophilus revealed a high degree of synteny, whereas the megaplasmids from the same strains were highly plastic. The T. oshimai JL-2 chromosome and megaplasmids shared little or no synteny with other sequenced Thermus strains. Phylogenomic analyses using a concatenated set of conserved proteins confirmed the phylogenetic and taxonomic assignments based on 16S rRNA phylogenetics. Both chromosomes encode a complete glycolysis, tricarboxylic acid (TCA) cycle, and pentose phosphate pathway plus glucosidases, glycosidases, proteases, and peptidases, highlighting highly versatile heterotrophic capabilities. Megaplasmids of both strains contained a gene cluster encoding enzymes predicted to catalyze the sequential reduction of nitrate to nitrous oxide; however, the nitrous oxide reductase required for the terminal step in denitrification was absent, consistent with their incomplete denitrification phenotypes. A sox gene cluster was identified in both chromosomes, suggesting a mode of chemolithotrophy. In addition, nrf and psr gene clusters in T. oshmai JL-2 suggest respiratory nitrite ammonification and polysulfide reduction as possible modes of anaerobic respiration. PMID:24019992

  15. Human milk oligosaccharides inhibit growth of group B Streptococcus

    NARCIS (Netherlands)

    Lin, Ann E; Autran, Chloe A; Szyszka, Alexandra; Escajadillo, Tamara; Huang, Mia; Godula, Kamil; Prudden, Anthony R; Boons, Geert-Jan|info:eu-repo/dai/nl/088245489; Lewis, Amanda L; Doran, Kelly S; Nizet, Victor; Bode, Lars

    2017-01-01

    Streptococcus agalactiae (group B Streptococcus, GBS) is a leading cause of invasive bacterial infections in newborns, typically acquired vertically during childbirth secondary to maternal vaginal colonization. Human milk oligosaccharides (HMOs) have important nutritional and biological activities

  16. Streptococcus pyogenes pili promote pharyngeal cell adhesion and biofilm formation

    National Research Council Canada - National Science Library

    Manetti, Andrea G. O; Zingaretti, Chiara; Falugi, Fabiana; Capo, Sabrina; Bombaci, Mauro; Bagnoli, Fabio; Gambellini, Gabriella; Bensi, Giuliano; Mora, Marirosa; Edwards, Andrew M; Musser, James M; Graviss, Edward A; Telford, John L; Grandi, Guido; Margarit, Immaculada

    2007-01-01

    Group A Streptococcus (GAS, Streptococcus pyogenes ) is a Gram‐positive human pathogen responsible for several acute diseases and autoimmune sequelae that account for half a million deaths worldwide every year...

  17. Streptococcus mutans and cardiovascular diseases

    Directory of Open Access Journals (Sweden)

    Kazuhiko Nakano

    2008-07-01

    Full Text Available Streptococcus mutans, a pathogen of dental caries, is known to be associated with bacteremia and infective endocarditis (IE. The bacterium has been classified into four serotypes, c, e, f, and k, based on the chemical composition of the serotype-specific rhamnose-glucose polymers. Serotype k, recently designated and initially found in blood isolates, features a drastic reduction of glucose side chains attached to the rhamnose backbone. Glucosyltransferases (GTFs, protein antigen (PA, and glucan-binding proteins (Gbps are major surface protein antigens of S. mutans, and in vitro analyses using isogenic mutants without those cell surface proteins showed that a PA-defective mutant had the least susceptibility to phagocytosis. Further, rat experiments demonstrated that infection with such defective mutants resulted in a longer duration of bacteremia, while S. mutans strains without GTFs were isolated from the extirpated heart valve of an IE patient. These results imply that some variation of cell surface components is correlated to the virulence of IE caused by S. mutans. In addition, S. mutans DNA has been frequently identified in cardiovascular specimens at a higher ratio than other periodontal bacteria, indicating its possible involvement in various types of cardiovascular diseases beside bacteremia and IE.

  18. The efficacy of neem extract on four microorganisms responsible for causing dental caries viz Streptococcus mutans, Streptococcus salivarius, Streptococcus mitis and Streptococcus sanguis: an in vitro study.

    Science.gov (United States)

    Chava, Venkateswara Rao; Manjunath, S M; Rajanikanth, A V; Sridevi, N

    2012-11-01

    HISTORY AND OBJECTIVES: From the ancient time, neem used to be the traditional medicine for many diseases and was mainly used for cleaning the oral cavity. The incidence of dental caries was less a few decades ago but now the incidence of caries is very aggressive. This might be due to change in dietary habits, life style and more tendency toward processed food. The objective of this study is to find out the truth that if the neem is really efficacious against caries-inducing microorganisms, mainly Streptococcus mutans, Streptococcus salivarius, Streptococcus mitis and Streptococcus sanguis. The dried neem sticks ground into a coarse powder and weighed into 5, 10 and 50 gm were added to 100 ml of deionized double distilled water. After soaking for 2 days, the water was filtered at 4 °C and the fine filtrate was inoculated onto blood agar plates contains individual species of microorganisms and incubated at 37 °C for 2 days. At maximum concentrations, neem extract has shown the maximum zone of inhibition on Streptococcus mutans. At less concentration, the efficacy of neem has shown some inhibition of growth for all the four species of microorganisms. Neem chewing provides the maximum benefits. Hence, the use of chewing sticks of neem can be recommended.

  19. Silica-Induced Protein (Sip) in Thermophilic Bacterium Thermus thermophilus Responds to Low Iron Availability.

    Science.gov (United States)

    Fujino, Yasuhiro; Nagayoshi, Yuko; Iwase, Makoto; Yokoyama, Takushi; Ohshima, Toshihisa; Doi, Katsumi

    2016-06-01

    Thermus thermophilus HB8 expresses silica-induced protein (Sip) when cultured in medium containing supersaturated silicic acids. Using genomic information, Sip was identified as a Fe(3+)-binding ABC transporter. Detection of a 1-kb hybridized band in Northern analysis revealed that sip transcription is monocistronic and that sip has its own terminator and promoter. The sequence of the sip promoter showed homology with that of the σ(A)-dependent promoter, which is known as a housekeeping promoter in HB8. Considering that sip is transcribed when supersaturated silicic acids are added, the existence of a repressor is presumed. DNA microarray analysis suggested that supersaturated silicic acids and iron deficiency affect Thermus cells similarly, and enhanced sip transcription was detected under both conditions. This suggested that sip transcription was initiated by iron deficiency and that the ferric uptake regulator (Fur) controlled the transcription. Three Fur gene homologues (TTHA0255, TTHA0344, and TTHA1292) have been annotated in the HB8 genome, and electrophoretic mobility shift assays revealed that the TTHA0344 product interacts with the sip promoter region. In medium containing supersaturated silicic acids, free Fe(3+) levels were decreased due to Fe(3+) immobilization on colloidal silica. This suggests that, because Fe(3+) ions are captured by colloidal silica in geothermal water, Thermus cells are continuously exposed to the risk of iron deficiency. Considering that Sip is involved in iron acquisition, Sip production may be a strategy to survive under conditions of low iron availability in geothermal water. The thermophilic bacterium Thermus thermophilus HB8 produces silica-induced protein (Sip) in the presence of supersaturated silicic acids. Sip has homology with iron-binding ABC transporter; however, the mechanism by which Sip expression is induced by silicic acids remains unexplained. We demonstrate that Sip captures iron and its transcription is

  20. Preventing invasive Group B Streptococcus (GBS) disease in South ...

    African Journals Online (AJOL)

    Streptococcus agalactiae is an encapsulated Gram-positive coccus that colonises the gastrointestinal and genito- urinary tracts. This organ ism belongs exclusively to Group B in Lancefield's grouping of Streptococcus species and therefore is referred to as Group B Streptococcus (GBS). Of the ten known serotypes, ...

  1. 21 CFR 866.3740 - Streptococcus spp. serological reagents.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Streptococcus spp. serological reagents. 866.3740... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3740 Streptococcus spp. serological reagents. (a) Identification. Streptococcus spp. serological reagents are devices...

  2. Septicemia caused by Streptococcus canis in a human.

    OpenAIRE

    Bert, F; Lambert-Zechovsky, N

    1997-01-01

    We describe a case of septicemia due to Streptococcus canis in a 77-year-old man. The organism was presumably transmitted from a domestic animal. Ulcers of the lower limbs were the likely portals of entry. The differentiation between Streptococcus canis and Streptococcus dysgalactiae was based on biochemical properties and DNA macrorestriction analysis by pulsed-field gel electrophoresis.

  3. The extent of co-metabolism of glucose and galactose by L. lactis changes with the expression of the lacSZ operon from Streptococcus thermophilus

    DEFF Research Database (Denmark)

    Solem, Christian; Købmann, Brian Jensen; Jensen, Peter Ruhdal

    2008-01-01

    and only glucose was metabolized in glycolysis. Interestingly, strains with low expression of the operon showed a mixed acid metabolism and co-metabolism of galactose and glucose. The lactose flux increased gradually with increasing expression of the lacSZ operon until an optimum was observed...... indicates that lactose transport is not rate-limiting for glycolysis in Loctococcus. Finally, an additional ATP drain was introduced into the fastest growing strain, CS2004, to test whether the ATP demand controlled glycolysis under these conditions, but in fact no increase in glycolytic flux was observed...

  4. ATP-driven calcium transport in membrane vesicles of Streptococcus sanguis. [Streptococcus sanguis; Streptococcus faecalis; Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Houng, H.; Lynn, A.R.; Rosen, B.P.

    1986-11-01

    Calcium transport was investigated in membrane vesicles prepared from the oral bacterium Streptococcus sanguis. Procedures were devised for the preparation of membrane vesicles capable of accumulation /sup 45/Ca/sup 2 +/. Uptake was ATP dependent and did not require a proton motive force. Calcium transport in these vesicles was compared with /sup 45/Ca/sup 2 +/ accumulation in membrane vesicles from Streptococcus faecalis and Escherichia coli. The data support the existence of an ATP-driven calcium pump in S. sanguis similar to that in S. faecalis. This pump, which catalyzes uptake into membrane vesicles, would be responsible for extrusion of calcium from intact cells.

  5. Homology modelling and docking analysis of L-lactate dehydrogenase from Streptococcus thermopilus

    Directory of Open Access Journals (Sweden)

    Vukić Vladimir R.

    2016-01-01

    Full Text Available The aim of this research was to create a three-dimensional model of L-lactate dehydrogenase from the main yoghurt starter culture - Streptococcus thermopilus, to analyse its structural features and investigate substrate binding in the active site. NCBI BlastP was used against the Protein Data Bank database in order to identify the template for construction of homology models. Multiple sequence alignment was performed using the program MUSCULE within the UGENE 1.11.3 program. Homology models were constructed using the program Modeller v. 9.17. The obtained 3D model was verified by Ramachandran plots. Molecular docking simulations were performed using the program Surflex-Dock. The highest sequence similarity was observed with L-lactate dehydrogenase from Lactobacillus casei subsp. casei, with 69% identity. Therefore, its structure (PDB ID: 2ZQY:A was selected as a modelling template for homology modelling. Active residues are by sequence similarity predicted: S. thermophilus - HIS181 and S. aureus - HIS179. Binding energy of pyruvate to L-lactate dehydrogenase of S. thermopilus was - 7.874 kcal/mol. Pyruvate in L-lactate dehydrogenase of S. thermopilus makes H bonds with catalytic HIS181 (1.9 Å, as well as with THR235 (3.6 Å. Although our results indicate similar position of substrates between L-lactate dehydrogenase of S. thermopilus and S. aureus, differences in substrate distances and binding energy values could influence the reaction rate. Based on these results, the L-lactate dehydrogenase model proposed here could be used as a guide for further research, such as transition states of the reaction through molecular dynamics. [Projekat Ministarstva nauke Republike Srbije, br. III 46009

  6. The cell envelope subtilisin-like proteinase is a virulence determinant for Streptococcus suis

    Directory of Open Access Journals (Sweden)

    Gottschalk Marcelo

    2010-02-01

    Full Text Available Abstract Background Streptococcus suis is a major swine pathogen and zoonotic agent that mainly causes septicemia, meningitis, and endocarditis. It has recently been suggested that proteinases produced by S. suis (serotype 2 are potential virulence determinants. In the present study, we screened a S. suis mutant library created by the insertion of Tn917 transposon in order to isolate a mutant deficient in a cell surface proteinase. We characterized the gene and assessed the proteinase for its potential as a virulence factor. Results Two mutants (G6G and M3G possessing a single Tn917 insertion were isolated. The affected gene coded for a protein (SSU0757 that shared a high degree of identity with Streptococccus thermophilus PrtS (95.9% and, to a lesser extent, with Streptococcus agalactiae CspA (49.5%, which are cell surface serine proteinases. The SSU0757 protein had a calculated molecular mass of 169.6 kDa and contained the catalytic triad characteristic of subtilisin family proteinases: motif I (Asp200, motif II (His239, and motif III (Ser568. SSU0757 also had the Gram-positive cell wall anchoring motif (Leu-Pro-X-Thr-Gly at the carboxy-terminus, which was followed by a hydrophobic domain. All the S. suis isolates tested, which belonged to different serotypes, possessed the gene encoding the SSU0757 protein. The two mutants devoid of subtilisin-like proteinase activity had longer generation times and were more susceptible to killing by whole blood than the wild-type parent strain P1/7. The virulence of the G6G and M3G mutants was compared to the wild-type strain in the CD1 mouse model. Significant differences in mortality rates were noted between the P1/7 group and the M3G and G6G groups (p Conclusion In summary, we identified a gene coding for a cell surface subtilisin-like serine proteinase that is widely distributed in S. suis. Evidences were brought for the involvement of this proteinase in S. suis virulence.

  7. Consideraciones sobre elaislamiento en exudados vaginales de Streptococcus morbillorum

    Directory of Open Access Journals (Sweden)

    J.M. F. Egido

    1995-06-01

    Full Text Available De el estúdio de 195 exudados vaginales enviados por el Servicio de Ginecologia de este hospital, durante el período 1988-1990, hemos seleccionado aquellos en los que el cultivo fue positivo para estreptococos, 58 (30% de los cuales 26 (44.8% correspondia a Streptococcus morbillorum, 9 (15.5% a Gardnerella vaginalis, 5 (8.6% a Enterococcus faecalis-durans, y a Streptococcus agalactiae, 3 (5.1% a Streptococcus mitis y Streptococcus mitis, 2 (3-4% a Streptococcus bovis y Streptococcus cremoris y 1 (1.7% a Streptococcus salivarius, Streptococcus equinus y Strptococcus sanguis II respectivamente. En todos los casos se observo antecedentes de actuacción medico- quirurjica en el tracto genital, y en el 52.8% de los casos fuô concomitante con el diagnostico clinico-micologico de candidiasis vaginal. La ideittificaccion bacteriologica se realizo mediante el sistema API 20 STREP (sistema api bioMêríeux GmbH, Nütingen, Alemania dando un patron tipico ("excelente identificacción" para el Streptococcus morbillorum.We have tested 195 vaginal secretions sent by Gynecology Service of this hospital between the years 1988 - 1990. We achieved positive culture for streptococci in 58 (30% of these cultures, 26 (44.8% corresponding to Streptococcus morbillorum 9 (15.5%, to Gardnerella vaginalis 5 (8.6%, to Enterococcus faecalis-durans and to Streptococcus agalactiae, 3 (5.1 % to Streptococcus mitis and milleri 2 (3-4%, to Streptococcus bovis and cremoris, and 1 (1.7% to Streptococcus salivarius, equinus and sanguis II respectively. We previously found that 52.8% of these patients were positive for vaginal candidiasis. The bacteriological identification done by the API 20 STREP System (bioMerieux GmbH, Nútingen, Germanyprovides a typical pattern ("good identification" for the Streptococcus morbillorum.

  8. Electrochemical properties and temperature dependence of a recombinant laccase from Thermus thermophilus.

    Science.gov (United States)

    Liu, Xin; Gillespie, Megan; Ozel, Ayca Demirel; Dikici, Emre; Daunert, Sylvia; Bachas, Leonidas G

    2011-01-01

    The electrochemical properties of a laccase from Thermus thermophilus HB27 (Tth-laccase) were characterized. The gene encoding the laccase was cloned and overexpressed in Escherichia coli. One-step purification of the corresponding apo-enzyme was achieved by nickel-affinity chromatography. Copper was incorporated into the apo-laccase as the cofactor to yield the holo-enzyme. The temperature-dependent catalytic activity of the laccase was investigated by spectrophotometric as well as electrochemical methods. Specifically, the catalytic properties of the enzyme were characterized by employing a photometric assay based on the oxidation of the substrate 2,2-azino-bis-(3-ethylbenzthiazoline-6-sulfonate) (ABTS). The electroactive substrate ABTS can be also monitored by cyclic voltammetry, thus allowing for determination of the enzymatic activity electrochemically. It was found that the recombinant laccase exhibited higher activity as the temperature increased up to 65 °C. Spectroscopic studies of Tth-laccase based on circular dichroism and fluorescence measurements are consistent with a thermally stable secondary structure of the protein.

  9. Engineering the substrate specificity of a thermophilic penicillin acylase from thermus thermophilus.

    Science.gov (United States)

    Torres, Leticia L; Cantero, Angel; del Valle, Mercedes; Marina, Anabel; López-Gallego, Fernando; Guisán, José M; Berenguer, José; Hidalgo, Aurelio

    2013-03-01

    A homologue of the Escherichia coli penicillin acylase is encoded in the genomes of several thermophiles, including in different Thermus thermophilus strains. Although the natural substrate of this enzyme is not known, this acylase shows a marked preference for penicillin K over penicillin G. Three-dimensional models were created in which the catalytic residues and the substrate binding pocket were identified. Through rational redesign, residues were replaced to mimic the aromatic binding site of the E. coli penicillin G acylase. A set of enzyme variants containing between one and four amino acid replacements was generated, with altered catalytic properties in the hydrolyses of penicillins K and G. The introduction of a single phenylalanine residue in position α188, α189, or β24 improved the K(m) for penicillin G between 9- and 12-fold, and the catalytic efficiency of these variants for penicillin G was improved up to 6.6-fold. Structural models, as well as docking analyses, can predict the positioning of penicillins G and K for catalysis and can demonstrate how binding in a productive pose is compromised when more than one bulky phenylalanine residue is introduced into the active site.

  10. Zinc and ATP Binding of the Hexameric AAA-ATPase PilF from Thermus thermophilus

    Science.gov (United States)

    Salzer, Ralf; Herzberg, Martin; Nies, Dietrich H.; Joos, Friederike; Rathmann, Barbara; Thielmann, Yvonne; Averhoff, Beate

    2014-01-01

    The traffic AAA-ATPase PilF is essential for pilus biogenesis and natural transformation of Thermus thermophilus HB27. Recently, we showed that PilF forms hexameric complexes containing six zinc atoms coordinated by conserved tetracysteine motifs. Here we report that zinc binding is essential for complex stability. However, zinc binding is neither required for pilus biogenesis nor natural transformation. A number of the mutants did not exhibit any pili during growth at 64 °C but still were transformable. This leads to the conclusion that type 4 pili and the DNA translocator are distinct systems. At lower growth temperatures (55 °C) the zinc-depleted multiple cysteine mutants were hyperpiliated but defective in pilus-mediated twitching motility. This provides evidence that zinc binding is essential for the role of PilF in pilus dynamics. Moreover, we found that zinc binding is essential for complex stability but dispensable for ATPase activity. In contrast to many polymerization ATPases from mesophilic bacteria, ATP binding is not required for PilF complex formation; however, it significantly increases complex stability. These data suggest that zinc and ATP binding increase complex stability that is important for functionality of PilF under extreme environmental conditions. PMID:25202014

  11. Role of Archaeal HerA Protein in the Biology of the Bacterium Thermus thermophilus

    Directory of Open Access Journals (Sweden)

    Alba Blesa

    2017-04-01

    Full Text Available Intense gene flux between prokaryotes result in high percentage of archaeal genes in the genome of the thermophilic bacteria Thermus spp. Among these archaeal genes a homolog to the Sulfolobus spp. HerA protein appears in all of the Thermus spp. strains so far sequenced (HepA. The role of HepA in Thermus thermophilus HB27 has been analyzed using deletion mutants, and its structure resolved at low resolution by electron microscopy. Recombinant HepA shows DNA-dependent ATPase activity and its structure revealed a double ring, conically-shaped hexamer with an upper diameter of 150 Å and a bottom module of 95 Å. A central pore was detected in the structure that ranges from 13 Å at one extreme, to 30 Å at the other. Mutants lacking HepA show defective natural competence and DNA donation capability in a conjugation-like process termed “transjugation”, and also high sensitivity to UV and dramatic sensitivity to high temperatures. These data support that acquisition of an ancestral archaeal HerA has been fundamental for the adaptation of Thermus spp. to high temperatures.

  12. Effect of C-terminal domain truncation of Thermus thermophilus trehalose synthase on its substrate specificity.

    Science.gov (United States)

    Cho, Chang-Bae; Park, Da-Yeon; Lee, Soo-Bok

    2017-01-01

    The C-terminal domain of the three-domain-comprising trehalose synthase from Thermus thermophilus was truncated in order to study the effect on the enzyme's activity and substrate specificity. Compared with the wild-type (WT) enzyme, the two truncated enzymes (DM1 and DM2) showed lower maltose- and trehalose-converting activities and a different transglycosylation reaction mechanism. In the mutants, the glucose moiety cleaved from the maltose substrate was released from the enzyme and intercepted by external glucose oxidase, preventing the production of trehalose. The WT enzyme, however, retained the glucose in the active site to effectively produce trehalose. In addition, DM1 synthesized much higher amounts of mannose-containing disaccharide trehalose analog (Man-TA) than did the WT and DM2. The results suggest that the C-terminal domain in the WT enzyme is important for retaining the glucose moiety within the active site. The mutant enzymes could be used to produce Man-TA, a postulated inhibitor of gut disaccharidases. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. HU histone-like DNA-binding protein from Thermus thermophilus: structural and evolutionary analyses.

    Science.gov (United States)

    Papageorgiou, Anna C; Adam, Panagiotis S; Stavros, Philemon; Nounesis, George; Meijers, Rob; Petratos, Kyriacos; Vorgias, Constantinos E

    2016-09-01

    The histone-like DNA-binding proteins (HU) serve as model molecules for protein thermostability studies, as they function in different bacteria that grow in a wide range of temperatures and show sequence diversity under a common fold. In this work, we report the cloning of the hutth gene from Thermus thermophilus, the purification and crystallization of the recombinant HUTth protein, as well as its X-ray structure determination at 1.7 Å. Detailed structural and thermodynamic analyses were performed towards the understanding of the thermostability mechanism. The interaction of HUTth protein with plasmid DNA in solution has been determined for the first time with MST. Sequence conservation of an exclusively thermophilic order like Thermales, when compared to a predominantly mesophilic order (Deinococcales), should be subject, to some extent, to thermostability-related evolutionary pressure. This hypothesis was used to guide our bioinformatics and evolutionary studies. We discuss the impact of thermostability adaptation on the structure of HU proteins, based on the detailed evolutionary analysis of the Deinococcus-Thermus phylum, where HUTth belongs. Furthermore, we propose a novel method of engineering thermostable proteins, by combining consensus-based design with ancestral sequence reconstruction. Finally, through the structure of HUTth, we are able to examine the validity of these predictions. Our approach represents a significant advancement, as it explores for the first time the potential of ancestral sequence reconstruction in the divergence between a thermophilic and a mainly mesophilic taxon, combined with consensus-based engineering.

  14. Structural characterization of neutral and acidic glycolipids from Thermus thermophilus HB8.

    Directory of Open Access Journals (Sweden)

    Yasuo Suda

    Full Text Available The structural characterization of glycolipids from Thermus thermophilus HB8 was performed in this study. Two neutral and one acidic glycolipids were extracted and purified by the modified TLC-blotting method, after which their chemical structures were determined by chemical composition analysis, mass spectrometry (MS and nuclear magnetic resonance (NMR spectroscopy. The structure of one of the neutral glycolipids, NGL-A, was Galp(α1-6GlcpNacyl(β1-2Glcp(α1-acyl(2Gro, and the other, NGL-C, was Galf(β1-2Galp(α1-6GlcpNacyl(β1-2Glcp(α1-acyl(2Gro. The structure of NGL-C was identical to that reported previously [Oshima, M. and Ariga, T. (1976 FEBS Lett. 64, 440]. Both neutral glycolipids shared a common structural unit found in the Thermus species. The acyl groups found in NGL-A and NGL-C, iso-type pentadecanoxy and heptadecanoxy fatty acid, were also the same as those found in this species. In contrast, the acidic glycolipid, AGL-B, possessed the structure of N-(((GlcpNAc(α1-acyl(2GroP-2GroAalkylamine. The alkyl group in AGL-B was an iso-type heptadecanyl, suggesting that the iso-type structure of the long alkyl chain is responsible for the thermal stability of the bacteria.

  15. Active site dynamics in NADH oxidase from Thermus thermophilus studied by NMR spin relaxation

    Energy Technology Data Exchange (ETDEWEB)

    Miletti, Teresa; Farber, Patrick J.; Mittermaier, Anthony, E-mail: anthony.mittermaier@mcgill.ca [McGill University, Department of Chemistry (Canada)

    2011-09-15

    We have characterized the backbone dynamics of NADH oxidase from Thermus thermophilus (NOX) using a recently-developed suite of NMR experiments designed to isolate exchange broadening, together with {sup 15}N R{sub 1}, R{sub 1{rho}}, and {l_brace}{sup 1}H{r_brace}-{sup 15}N steady-state NOE relaxation measurements performed at 11.7 and 18.8 T. NOX is a 54 kDa homodimeric enzyme that belongs to a family of structurally homologous flavin reductases and nitroreductases with many potential biotechnology applications. Prior studies have suggested that flexibility is involved in the catalytic mechanism of the enzyme. The active site residue W47 was previously identified as being particularly important, as its level of solvent exposure correlates with enzyme activity, and it was observed to undergo 'gating' motions in computer simulations. The NMR data are consistent with these findings. Signals from W47 are dynamically broadened beyond detection and several other residues in the active site have significant R{sub ex} contributions to transverse relaxation rates. In addition, the backbone of S193, whose side chain hydroxyl proton hydrogen bonds directly with the FMN cofactor, exhibits extensive mobility on the ns-ps timescale. We hypothesize that these motions may facilitate structural rearrangements of the active site that allow NOX to accept both FMN and FAD as cofactors.

  16. Characterisation of the DNA gyrase from the thermophilic eubacterium Thermus thermophilus.

    Science.gov (United States)

    Aung, Htin Lin; Samaranayaka, Chamil U K; Enright, Rochelle; Beggs, Kyle T; Monk, Brian C

    2015-03-01

    DNA gyrase is a type IIA topoisomerase found in bacteria but not in humans. The enzyme is required for bacterial DNA replication and transcription, and is an important antibacterial target that is sensitive to the widely-used fluoroquinolone drugs. Due to the emergence of fluoroquinolone resistance, the discovery of new classes of drugs that target DNA gyrase is urgent. The DNA gyrase holoenzyme is a heterodimer of subunit pairs (A2B2). The 90 kDa A subunits bind, cleave, and rejoin double stranded DNA. The enzyme introduces negative supercoils into closed circular bacterial DNA using ATP hydrolysis catalysed by the 70 kDa B subunits. Subdomains of DNA gyrase subunits have been crystallised for structural analysis and the resulting models used to improve drugs that target the DNA binding region and active site. While crystal structures are available for topoisomerase IV complexes with cleaved DNA, there is none for the complete DNA gyrase complex with substrate DNA bound. Thermophiles offer significant advantages in obtaining stable enzymes for structural and functional studies. In order to develop a capability for drug screening and structure-directed drug discovery we have reconstituted a functional and drug-sensitive DNA gyrase complex using heterologously expressed subunits from the thermophile Thermus thermophilus. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Long-Range PCR Amplification of DNA by DNA Polymerase III Holoenzyme from Thermus thermophilus

    Directory of Open Access Journals (Sweden)

    Wendy Ribble

    2015-01-01

    Full Text Available DNA replication in bacteria is accomplished by a multicomponent replicase, the DNA polymerase III holoenzyme (pol III HE. The three essential components of the pol III HE are the α polymerase, the β sliding clamp processivity factor, and the DnaX clamp-loader complex. We report here the assembly of the functional holoenzyme from Thermus thermophilus (Tth, an extreme thermophile. The minimal holoenzyme capable of DNA synthesis consists of α, β and DnaX (τ and γ, δ and δ′ components of the clamp-loader complex. The proteins were each cloned and expressed in a native form. Each component of the system was purified extensively. The minimum holoenzyme from these five purified subunits reassembled is sufficient for rapid and processive DNA synthesis. In an isolated form the α polymerase was found to be unstable at temperatures above 65°C. We were able to increase the thermostability of the pol III HE to 98°C by addition and optimization of various buffers and cosolvents. In the optimized buffer system we show that a replicative polymerase apparatus, Tth pol III HE, is capable of rapid amplification of regions of DNA up to 15,000 base pairs in PCR reactions.

  18. Hierarchical Control of Nitrite Respiration by Transcription Factors Encoded within Mobile Gene Clusters of Thermus thermophilus.

    Science.gov (United States)

    Alvarez, Laura; Quintáns, Nieves G; Blesa, Alba; Baquedano, Ignacio; Mencía, Mario; Bricio, Carlos; Berenguer, José

    2017-12-01

    Denitrification in Thermus thermophilus is encoded by the nitrate respiration conjugative element (NCE) and nitrite and nitric oxide respiration (nic) gene clusters. A tight coordination of each cluster's expression is required to maximize anaerobic growth, and to avoid toxicity by intermediates, especially nitric oxides (NO). Here, we study the control of the nitrite reductases (Nir) and NO reductases (Nor) upon horizontal acquisition of the NCE and nic clusters by a formerly aerobic host. Expression of the nic promoters PnirS, PnirJ, and PnorC, depends on the oxygen sensor DnrS and on the DnrT protein, both NCE-encoded. NsrR, a nic-encoded transcription factor with an iron-sulfur cluster, is also involved in Nir and Nor control. Deletion of nsrR decreased PnorC and PnirJ transcription, and activated PnirS under denitrification conditions, exhibiting a dual regulatory role never described before for members of the NsrR family. On the basis of these results, a regulatory hierarchy is proposed, in which under anoxia, there is a pre-activation of the nic promoters by DnrS and DnrT, and then NsrR leads to Nor induction and Nir repression, likely as a second stage of regulation that would require NO detection, thus avoiding accumulation of toxic levels of NO. The whole system appears to work in remarkable coordination to function only when the relevant nitrogen species are present inside the cell.

  19. Proton transfer in ba(3) cytochrome c oxidase from Thermus thermophilus.

    Science.gov (United States)

    von Ballmoos, Christoph; Adelroth, Pia; Gennis, Robert B; Brzezinski, Peter

    2012-04-01

    The respiratory heme-copper oxidases catalyze reduction of O(2) to H(2)O, linking this process to transmembrane proton pumping. These oxidases have been classified according to the architecture, location and number of proton pathways. Most structural and functional studies to date have been performed on the A-class oxidases, which includes those that are found in the inner mitochondrial membrane and bacteria such as Rhodobacter sphaeroides and Paracoccus denitrificans (aa(3)-type oxidases in these bacteria). These oxidases pump protons with a stoichiometry of one proton per electron transferred to the catalytic site. The bacterial A-class oxidases use two proton pathways (denoted by letters D and K, respectively), for the transfer of protons to the catalytic site, and protons that are pumped across the membrane. The B-type oxidases such as, for example, the ba(3) oxidase from Thermus thermophilus, pump protons with a lower stoichiometry of 0.5 H(+)/electron and use only one proton pathway for the transfer of all protons. This pathway overlaps in space with the K pathway in the A class oxidases without showing any sequence homology though. Here, we review the functional properties of the A- and the B-class ba(3) oxidases with a focus on mechanisms of proton transfer and pumping. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Proline dehydrogenase from Thermus thermophilus does not discriminate between FAD and FMN as cofactor.

    Science.gov (United States)

    Huijbers, Mieke M E; Martínez-Júlvez, Marta; Westphal, Adrie H; Delgado-Arciniega, Estela; Medina, Milagros; van Berkel, Willem J H

    2017-03-03

    Flavoenzymes are versatile biocatalysts containing either FAD or FMN as cofactor. FAD often binds to a Rossmann fold, while FMN prefers a TIM-barrel or flavodoxin-like fold. Proline dehydrogenase is denoted as an exception: it possesses a TIM barrel-like fold while binding FAD. Using a riboflavin auxotrophic Escherichia coli strain and maltose-binding protein as solubility tag, we produced the apoprotein of Thermus thermophilus ProDH (MBP-TtProDH). Remarkably, reconstitution with FAD or FMN revealed that MBP-TtProDH has no preference for either of the two prosthetic groups. Kinetic parameters of both holo forms are similar, as are the dissociation constants for FAD and FMN release. Furthermore, we show that the holo form of MBP-TtProDH, as produced in E. coli TOP10 cells, contains about three times more FMN than FAD. In line with this flavin content, the crystal structure of TtProDH variant ΔABC, which lacks helices αA, αB and αC, shows no electron density for an AMP moiety of the cofactor. To the best of our knowledge, this is the first example of a flavoenzyme that does not discriminate between FAD and FMN as cofactor. Therefore, classification of TtProDH as an FAD-binding enzyme should be reconsidered.

  1. Site-directed mutation of a laccase from Thermus thermophilus: Effect on the activity profile

    Directory of Open Access Journals (Sweden)

    Liu Xin

    2012-01-01

    Full Text Available A site-directed mutant R453T of a laccase from Thermus thermophilus HB27 (Tth-laccase was constructed in order to investigate the effect on laccase catalytic properties. The mutated gene was cloned and overexpressed in Escherichia coli. Nickel-affinity purification was achieved and followed by copper ion incorporation. The mature mutated enzyme was quantitatively equal to the wild type. A photometric assay based on the oxidation of the substrate 2,2-azino-bis-(3- ethylbenzthiazoline-6-sulfonate (ABTS was employed in comparison with the wild-type Tth-laccase on catalytic properties. The R453T mutant exhibited improvement in substrate affinity and specific activity at room temperature, whereas those parameters were not significantly influenced when the temperature increased up to 65°C or higher. The mutant had better catalytic activity than that of the wild type at acidic pH. Investigated by circular dichroism spectroscopy, the mutant Tth-laccase displayed similar profiles at low and high temperatures.

  2. Mixed Streptococcus pneumoniae and Streptococcus pyogenes meningitis in an immunocompromised adult patient: a case report.

    Science.gov (United States)

    Demerle, Clémence; Ivanov, Vadim; Mercier, Cédric; Costello, Régis; Drancourt, Michel

    2015-11-29

    Community-acquired meningitis is a monomicrobial infection caused by either viruses or bacteria in the vast majority of patients. We report here one exceptional case of a patient with mixed bacterial meningitis due to Streptococcus pneumoniae and Streptococcus pyogenes. We report the case of a 68-year-old immunocompromised Caucasian man suffering from otitis and then meningitis caused by Streptococcus pneumoniae and Streptococcus pyogenes. Bacteria were undistinguishable by direct microscopic examination of the cerebrospinal fluid. He responded well to treatment with cefotaxime and dexamethasone, with no sequelae observed at the 4-month follow-up. This first reported case of mixed S. pneumoniae and S. pyogenes meningitis illustrates the life-threatening consequences of barotrauma in immunocompromised patients suffering from otorhinolaryngeal infections.

  3. Thermus thermophilus as a cell factory for the production of a thermophilic Mn-dependent catalase which fails to be synthesized in an active form in Escherichia coli.

    Science.gov (United States)

    Hidalgo, Aurelio; Betancor, Lorena; Moreno, Renata; Zafra, Olga; Cava, Felipe; Fernández-Lafuente, Roberto; Guisán, José M; Berenguer, José

    2004-07-01

    Thermostable Mn-dependent catalases are promising enzymes in biotechnological applications as H(2)O(2)-detoxifying systems. We cloned the genes encoding Mn-dependent catalases from Thermus thermophilus HB27 and HB8 and a less thermostable mutant carrying two amino acid replacements (M129V and E293G). When the wild-type and mutant genes were overexpressed in Escherichia coli, unmodified or six-His-tagged proteins of the expected size were overproduced as inactive proteins. Several attempts to obtain active forms or to activate the overproduced proteins were unsuccessful, even when soluble and thermostable proteins were used. Therefore, a requirement for a Thermus-specific activation factor was suggested. To overcome this problem, the Mn-dependent catalase genes were overexpressed directly in T. thermophilus under the control of the Pnar promoter. This promoter belongs to a respiratory nitrate reductase from of T. thermophilus HB8, whose transcription is activated by the combined action of nitrate and anoxia. Upon induction in T. thermophilus HB8, a 20- to 30-fold increase in catalase specific activity was observed, whereas a 90- to 110-fold increase was detected when the laboratory strain T. thermophilus HB27::nar was used as the host. The thermostability of the overproduced wild-type catalase was identical to that previously reported for the native enzyme, whereas decreased stability was detected for the mutant derivative. Therefore, our results validate the use of T. thermophilus as an alternative cell factory for the overproduction of thermophilic proteins that fail to be expressed in well-known mesophilic hosts.

  4. Interaction of anti-kojibiose antibody with the lipoteichoic acids from Streptococcus faecalis and Streptococcus faecium.

    OpenAIRE

    Kessler, R E; Duke, J.; Goldstein, I J

    1984-01-01

    Antisera prepared in rabbits by immunization with p-aminophenyl beta-kojibioside conjugated to bovine serum albumin (antikojibiose sera), readily agglutinated whole cells of Streptococcus faecalis or Streptococcus faecium, and showed specific reactions with the lipoteichoic acids (LTAs) of these streptococci by passive hemagglutination, microscale enzyme-linked immunosorbent assay, and crossed immunoelectrophoresis. The interaction of the antikojibiose sera with the LTAs was inhibited best by...

  5. Glucose Uptake by Streptococcus mutans, Streptococcus mitis, and Actinomyces viscosus in the Presence of Human Saliva

    OpenAIRE

    Germaine, Greg, R.; Tellefson, Lois M.

    1982-01-01

    Glucose uptake was examined by using whole-cell suspensions of Streptococcus mutans (strains BHT, Ingbritt, and GS-5), Streptococcus mitis (strains 9811 and 72×41), and Actinomyces viscosus (strains T6 and WVU626) incubated for up to 90 min in 0 to 82% (vol/vol) human whole salivary supernatant. Glucose uptake by the S. mutans strains was completely inhibited at all saliva concentrations. Dithiothreitol (DTT), present during saliva incubation, prevented saliva inhibition. Glucose uptake was a...

  6. Antibacterial activity of Bixa orellana L. (achiote) against Streptococcus mutans and Streptococcus sanguinis

    OpenAIRE

    Medina-Flores, Dyanne; Ulloa-Urizar, Gabriela; Camere-Colarossi, Rosella; Caballero-García, Stefany; Mayta-Tovalino, Frank; del Valle-Mendoza, Juana

    2016-01-01

    Objective To evaluate the cytotoxic and antibacterial effect of Bixa orellana L. (B. orellana) (achiote) methanol extract against Streptococcus mutans (ATCC 25175) (S. mutans) and Streptococcus sanguinis (ATCC 10556) (S. sanguinis). Methods Two methanol extracts of B. orellana were prepared in vitro, from the seeds and leaves. The antibacterial activity of extracts against S. mutans and S. sanguinis was evaluated using the cup-plate agar diffusion method. The minimum inhibitory co...

  7. Streptococcus loxodontisalivarius sp. nov. and Streptococcus saliviloxodontae sp. nov., isolated from oral cavities of elephants.

    Science.gov (United States)

    Saito, Masanori; Shinozaki-Kuwahara, Noriko; Hirasawa, Masatomo; Takada, Kazuko

    2014-09-01

    Four Gram-stain-positive, catalase-negative, coccoid-shaped organisms were isolated from elephant oral cavities. The isolates were tentatively identified as streptococcal species based on the results of biochemical tests. Comparative 16S rRNA gene sequencing studies confirmed the organisms to be members of the genus Streptococcus. Two isolates (NUM 6304(T) and NUM 6312) were related most closely to Streptococcus salivarius with 96.8 % and 93.1 % similarity based on the 16S rRNA gene and the RNA polymerase β subunit encoding gene (rpoB), respectively, and to Streptococcus vestibularis with 83.7 % similarity based on the 60 kDa heat-shock protein gene (groEL). The other two isolates (NUM 6306(T) and NUM 6318) were related most closely to S. vestibularis with 97.0 % and 82.9 % similarity based on the 16S rRNA and groEL genes, respectively, and to S. salivarius with 93.5 % similarity based on the rpoB gene. Based on phylogenetic and phenotypic evidence, these isolates are suggested to represent novel species of the genus Streptococcus, for which the names Streptococcus loxodontisalivarius sp. nov. (type strain NUM 6304(T) = JCM 19287(T) = DSM 27382(T)) and Streptococcus saliviloxodontae sp. nov. (type strain NUM 6306(T) = JCM 19288(T) = DSM 27513(T)) are proposed. © 2014 IUMS.

  8. Streptococcus moroccensis sp. nov. and Streptococcus rifensis sp. nov., isolated from raw camel milk.

    Science.gov (United States)

    Kadri, Zaina; Amar, Mohamed; Ouadghiri, Mouna; Cnockaert, Margo; Aerts, Maarten; El Farricha, Omar; Vandamme, Peter

    2014-07-01

    Two catalase- and oxidase-negative Streptococcus-like strains, LMG 27682(T) and LMG 27684(T), were isolated from raw camel milk in Morocco. Comparative 16S rRNA gene sequencing assigned these bacteria to the genus Streptococcus with Streptococcus rupicaprae 2777-2-07(T) as their closest phylogenetic neighbour (95.9% and 95.7% similarity, respectively). 16S rRNA gene sequence similarity between the two strains was 96.7%. Although strains LMG 27682(T) and LMG 27684(T) shared a DNA-DNA hybridization value that corresponded to the threshold level for species delineation (68%), the two strains could be distinguished by multiple biochemical tests, sequence analysis of the phenylalanyl-tRNA synthase (pheS), RNA polymerase (rpoA) and ATP synthase (atpA) genes and by their MALDI-TOF MS profiles. On the basis of these considerable phenotypic and genotypic differences, we propose to classify both strains as novel species of the genus Streptococcus, for which the names Streptococcus moroccensis sp. nov. (type strain, LMG 27682(T)  = CCMM B831(T)) and Streptococcus rifensis sp. nov. (type strain, LMG 27684(T)  = CCMM B833(T)) are proposed. © 2014 IUMS.

  9. Streptococcus milleri and second trimester abortion.

    Science.gov (United States)

    MacGowan, A P; Terry, P B

    1987-01-01

    Review of 214 fetal necropsies performed in the department of pathology, University of Aberdeen, showed 40 cases of chorioamnionitis or intrauterine pneumonia, five of which were associated with Streptococcus milleri. In two cases there was good evidence to implicate S milleri as the cause of infected abortion while in the other cases its pathogenic role was less clear. PMID:3558861

  10. Bacteriocin and Hemolysin from Streptococcus faecium

    OpenAIRE

    Nakagawa, Shizutoshi; Matsuo, Yoshiyasu

    1981-01-01

    The bacteriocin and hemolysin produced by a Streptococcus faecium strain were partially separated after gel filtration on Ultrogel AcA-22. The molecular weight of bacteriocin was approximately 300,000, and that of hemolysin was 220,000. Non-bacteriocinogenic mutants retained the hemolytic activity. Production of hemolysin required glucose, whereas that of bacteriocin did not.

  11. 9230 FECAL ENTEROCOCCUS/STREPTOCOCCUS GROUPS

    Science.gov (United States)

    In 1903 the genus name Enterococcus was proposed for gram-positive, catalase-negative, coccoid-shaped bacterial of intestinal origin. Several years later, it was suggested that the genus name be changed to Streptococcus because of the organisms' ability to form chains of coccoid...

  12. Antimicrobial activity of propolis against Streptococcus mutans ...

    African Journals Online (AJOL)

    The ethanol extract of propolis (EEP) obtained from beehives of honeybee (Apis mellifera) was investigated for its antimicrobial activities against Streptococcus mutans isolated from dental caries. Agar well diffusion and minimum inhibitory concentration (MIC) determinations were the methods used in this study. The carious ...

  13. Dyrkningsnegativ Streptococcus pneumoniae endokarditis diagnosticeret med polymerasekaedereaktion

    DEFF Research Database (Denmark)

    Rasmussen, Rasmus Vedby; Kemp, Michael; Bangsborg, Jette Marie

    2008-01-01

    A 60-year old man was admitted with sepsis and meningitis of unknown aetiology. Underlying aortic valve endocarditis was diagnosed by echocardiography and severe insufficiency led to aortic valve replacement. Application of broad-range PCR to cusp tissue revealed a DNA product, and a diagnosis of...... of Streptococcus pneumoniae endocarditis was obtained by DNA sequencing....

  14. Detection and quantification of Streptococcus pneumoniae from ...

    African Journals Online (AJOL)

    The aim of this study was to develop a real time polymerase chain reaction (PCR) for quantitative detection of Streptococcus pneumoniae from clinical respiratory specimens. Initially, 184 respiratory specimens from patients with community acquired pneumonia (CAP) (n = 129) and 55 cases with hospital associated ...

  15. Susceptibility Pattern of Nasopharyngeal Isolates of Streptococcus ...

    African Journals Online (AJOL)

    Aims: To determine the rate of nasopharyngeal colonization of Streptococcus pneumoniae among nursery school children in Enugu urban and to determine their antibiotic susceptibility pattern particularly the penicillin resistant strains. Methods: Specimens were collected from the nasopharynx of 385 apparently healthy ...

  16. NEW VIRULENCE FACTORS OF STREPTOCOCCUS PNEUMONIAE

    NARCIS (Netherlands)

    Hermans, Peter Wilhelmus Maria; Bootsma, Jeanette Hester; Burghout, Pieter Jan; Kuipers, Oscar; Bijlsma, Johanna Jacoba Elisabeth; Kloosterman, Tomas Gerrit; Andersen, Christian O.

    2011-01-01

    The present invention provides proteins/genes, which are essential for survival, and consequently, for virulence of Streptococcus pneumoniae in vivo, and thus are ideal vaccine candidates for a vaccine preparation against pneumococcal infection. Further, also antibodies against said protein(s) are

  17. Recurrent Sepsis Caused by Streptococcus pyogenes▿

    OpenAIRE

    Rasmussen, Magnus

    2011-01-01

    I report that a 75-year-old man with severe atherosclerosis experienced two episodes of bacteremia with Streptococcus pyogenes of type emm87. Recurrent sepsis with S. pyogenes is extremely rare, and a foot ulcer was the suspected point of entry. The patient did not develop opsonizing antibodies to the isolate.

  18. Streptococcus constellatus and Prevotella bivia Penile Abscess

    Directory of Open Access Journals (Sweden)

    Sandhya Nalmas

    2007-01-01

    Full Text Available Streptococcus constellatus (S. constellatus is known to cause abscesses in the oral, genitourinary, and gastrointestinal tracts, frequently in association with anaerobic bacteria. We report a rare case of S. constellatus and Prevotella bivia (P. bivia causing a penile abscess, which was successfully treated with surgical drainage and antibiotic treatment.

  19. Streptococcus pneumoniae colonization in remote African Pygmies

    NARCIS (Netherlands)

    Schaumburg, Frieder; Alabi, Abraham; von Eiff, Christof; Flamen, Arnaud; Traore, Hafsatou; Grobusch, Martin Peter; Peters, Georg; Kremsner, Peter Gottfried; van der Linden, Mark

    2013-01-01

    African Pygmies have many risk factors for invasive pneumococcal disease (IPD), such as low socioeconomic status and low quality of health care. We characterized Streptococcus pneumoniae from Gabonese Pygmies and analyzed risk factors for S. pneumoniae carriage to improve prophylaxis and therapy of

  20. PENICILLIN–RESISTANT STREPTOCOCCUS PNEUMONIAE – A ...

    African Journals Online (AJOL)

    This is a review of literature on the epidemiology, mechanism of resistance, laboratory identification, treatment, prevention and control of Penicillin Resistant Pneumococci (PRP), with emphasis on the problems of identification and reporting in developing countries. Key Words: penicillin, Streptococcus pneumoniae, resistant ...

  1. Antimicrobial activity of propolis against Streptococcus mutans

    African Journals Online (AJOL)

    USER

    2010-08-02

    Aug 2, 2010 ... The ethanol extract of propolis (EEP) obtained from beehives of honeybee (Apis mellifera) was investigated for its antimicrobial activities against Streptococcus mutans isolated from dental caries. Agar well diffusion and minimum inhibitory concentration (MIC) determinations were the methods used.

  2. Streptococcus pneumoniae as a Cause of Salpingitis

    OpenAIRE

    Patterson, David; Johnson, Celeste M.; Monif, Gilles R. G.

    1994-01-01

    Background: A case of pneumococcal septicemia associated with laparoscopically documented acute salpingitis is reported. Case: Gram-stained cul-de-sac pus revealed gram-positive encapsulated diplococci. Conclusion: This case coupled with reanalysis of prior genital tract involvement in nonpregnant individuals argues that Streptococcus pneumoniae can mimic gonococcal diseases.

  3. Streptococcus equisimilis Pneumonia in a compromised host.

    OpenAIRE

    Siefkin, A D; Peterson, D L; Hansen, B

    1983-01-01

    A fatal case of Streptococcus equisimilis pneumonia and septicemia is described in a young man with Hodgkin's disease. The disease course consisted of exudative pharyngitis, macular rash, septic shock, disseminated intravascular coagulation, deep vein thrombosis, and pulmonary embolization. S. equisimilis was isolated from blood, throat, and sputum cultures antemortem and from lung cultures at autopsy.

  4. Antibacterial activity of Euphorbia hirta against Streptococcus ...

    African Journals Online (AJOL)

    This investigation was conducted to determine the in-vitro effect of aqueous, ethanol and methanol crude extracts of Euphorbia hirta at concentrations ranging from 10mg/ml – 100mg/ml against three pathogenic bacteria (Streptococcus pneumoniae, Klebsiella pneumoniae and Proteus vulgaris) using cup plate method.

  5. streptococcus pneumoniae , klebsiella pneumoniae proteus vulgaris

    African Journals Online (AJOL)

    DR. AMINU

    ABSTRACT. This investigation was conducted to determine the in-vitro effect of aqueous, ethanol and methanol crude extracts of Euphorbia hirta at concentrations ranging from 10mg/ml – 100mg/ml against three pathogenic bacteria (Streptococcus pneumoniae, Klebsiella pneumoniae and Proteus vulgaris) using cup plate ...

  6. Streptococcus sanguis meningitis: report of a case.

    Science.gov (United States)

    Chotmongkol, Verajit; Panthavasit, Jedsada; Vorachit, Malai

    2002-07-01

    A 35-year-old woman who presented with acute purulent meningitis and hearing loss was reported. No bacteria was seen with Gram' s stain of cerebrospinal fluid (CSF). CSF grew Streptococcus viridans, which was subsequently identified to be S. sanguis. The patient improved after treatment, including hearing.

  7. How Does Streptococcus pneumoniae Invade the Brain?

    NARCIS (Netherlands)

    Iovino, Federico; Seinen, Jolien; Henriques-Normark, Birgitta; van Dijl, Jan Maarten

    Streptococcus pneumoniae (the pneumococcus) is the major cause of bacterial meningitis. The mechanisms by which pneumococci from the bloodstream penetrate the blood-brain barrier to reach the brain are not fully understood. Receptor-mediated adhesion of the bacteria to the brain endothelium is

  8. A comparison of structural and evolutionary attributes of Escherichia coli and Thermus thermophilus small ribosomal subunits: signatures of thermal adaptation.

    Directory of Open Access Journals (Sweden)

    Saurav Mallik

    Full Text Available Here we compare the structural and evolutionary attributes of Thermus thermophilus and Escherichia coli small ribosomal subunits (SSU. Our results indicate that with few exceptions, thermophilic 16S ribosomal RNA (16S rRNA is densely packed compared to that of mesophilic at most of the analogous spatial regions. In addition, we have located species-specific cavity clusters (SSCCs in both species. E. coli SSCCs are numerous and larger compared to T. thermophilus SSCCs, which again indicates densely packed thermophilic 16S rRNA. Thermophilic ribosomal proteins (r-proteins have longer disordered regions than their mesophilic homologs and they experience larger disorder-to-order transitions during SSU-assembly. This is reflected in the predicted higher conformational changes of thermophilic r-proteins compared to their mesophilic homologs during SSU-assembly. This high conformational change of thermophilic r-proteins may help them to associate with the 16S ribosomal RNA with high complementary interfaces, larger interface areas, and denser molecular contacts, compared to those of mesophilic. Thus, thermophilic protein-rRNA interfaces are tightly associated with 16S rRNA than their mesophilic homologs. Densely packed 16S rRNA interior and tight protein-rRNA binding of T. thermophilus (compared to those of E. coli are likely the signatures of its thermal adaptation. We have found a linear correlation between the free energy of protein-RNA interface formation, interface size, and square of conformational changes, which is followed in both prokaryotic and eukaryotic SSU. Disorder is associated with high protein-RNA interface polarity. We have found an evolutionary tendency to maintain high polarity (thereby disorder at protein-rRNA interfaces, than that at rest of the protein structures. However, some proteins exhibit exceptions to this general trend.

  9. Identification of novel esterase-active enzymes from hot environments by use of the host bacterium Thermus thermophilus

    Directory of Open Access Journals (Sweden)

    Benedikt eLeis

    2015-04-01

    Full Text Available Functional metagenomic screening strategies, which are independent of known sequence information, can lead to the identification of truly novel genes and enzymes. Since E. coli has been used exhaustively for this purpose as a host, it is important to establish alternative expression hosts and to use them for functional metagenomic screening for new enzymes. In this study we show that Thermus thermophilus HB27 is an excellent screening host and can be used as an alternative provider of truly novel biocatalysts. In a previous study we constructed the mutant strain BL03 that was no longer able to grow on defined minimal medium supplemented with tributyrin as the sole carbon source and could be used as a host to screen for metagenomic DNA fragments that could complement growth on tributyrin. Several thousand single fosmid clones from thermophilic metagenomic libraries from heated compost and hot spring water samples were subjected to a comparative screening for esterase activity in both T. thermophilus strain BL03 and E. coli EPI300. We scored a greater number of active clones in the thermophilic bacterium than in the mesophilic E. coli. From all clones functionally screened in E. coli, only two thermostable α/β-fold hydrolase enzymes with high amino acid sequence similarity to already characterized enzymes were identifiable. In contrast, five further fosmids were found that conferred lipolytic activities in T. thermophilus. Four open reading frames (ORFs were found which did not share significant similarity to known esterase enzymes. Two of the genes were expressed in both hosts and the novel thermophilic esterases, which based on their primary structures could not be assigned to known esterase or lipase families, were purified and preliminarily characterized. Our work underscores the benefit of using additional screening hosts other than E. coli for the identification of novel biocatalysts with industrial relevance.

  10. Electron transfer among the CuA-, heme b- and a3-centers of Thermus thermophilus cytochrome ba3

    DEFF Research Database (Denmark)

    Farver, Ole; Chen, Ying; Fee, James A

    2006-01-01

    . and Pecht, I. (2006) Rates and equilibrium of CuA to heme a electron transfer in Paracoccus denitrificans cytochrome c oxidase. Biophys. J. 90, 2131-2137]. Investigating this process in the cytochrome ba(3) of Thermus thermophilus (Tt), we now show that MNA(*) also reduces Cu(A) with a subsequent ET......The 1-methyl-nicotinamide radical (MNA(*)), produced by pulse radiolysis has previously been shown to reduce the Cu(A)-site of cytochromes aa(3), a process followed by intramolecular electron transfer (ET) to the heme a but not to the heme a(3) [Farver, O., Grell, E., Ludwig, B., Michel, H...

  11. Regulation of neuraminidase expression in Streptococcus pneumoniae

    Directory of Open Access Journals (Sweden)

    Gualdi Luciana

    2012-09-01

    Full Text Available Abstract Background Sialic acid (N-acetylneuraminic acid; NeuNAc is one of the most important carbohydrates for Streptococcus pneumoniae due of its role as a carbon and energy source, receptor for adhesion and invasion and molecular signal for promotion of biofilm formation, nasopharyngeal carriage and invasion of the lung. Results In this work, NeuNAc and its metabolic derivative N-acetyl mannosamine (ManNAc were used to analyze regulatory mechanisms of the neuraminidase locus expression. Genomic and metabolic comparison to Streptococcus mitis, Streptococcus oralis, Streptococcus gordonii and Streptococcus sanguinis elucidates the metabolic association of the two amino sugars to different parts of the locus coding for the two main pneumococcal neuraminidases and confirms the substrate specificity of the respective ABC transporters. Quantitative gene expression analysis shows repression of the locus by glucose and induction of all predicted transcriptional units by ManNAc and NeuNAc, each inducing with higher efficiency the operon encoding for the transporter with higher specificity for the respective amino sugar. Cytofluorimetric analysis demonstrated enhanced surface exposure of NanA on pneumococci grown in NeuNAc and ManNAc and an activity assay allowed to quantify approximately twelve times as much neuraminidase activity on induced cells as opposed to glucose grown cells. Conclusions The present data increase the understanding of metabolic regulation of the nanAB locus and indicate that experiments aimed at the elucidation of the relevance of neuraminidases in pneumococcal virulence should possibly not be carried out on bacteria grown in glucose containing media.

  12. Functional role of C-terminal domain of Thermus thermophilus leucyl-tRNA synthetase

    Directory of Open Access Journals (Sweden)

    Tukalo M. A.

    2010-11-01

    Full Text Available Aim. To study a role of C-terminal domain of T. thermophilus leucyl-tRNA synthetase (LeuRSTT in the reactions of aminoacylation and editing. Methods. A mutant of LeuRSTT without C- terminal domain (ΔС was obtained by the method of mutagenesis. The kinetic constants in aminoacylation reaction catalyzed by LeuRS and its mutant (ΔС were determined by the methods of equilibrium enzyme kinetics. To evaluate the contribution of C-terminal domain to interaction of the enzyme with tRNALeu, Kd of a complex between tRNA and LeuRSTT and its mutant ΔС was determined by fluorescence titration. Results. The C-terminal domain is shown to play a significant role in the aminoacylation and editing reactions of LeuRSTT and not essential for the activity in the reaction of amino acid activation. The kinetic parameters of aminoacylation of tRNALeu and tRNATyr by LeuRS and ΔС mutant were also determined, their analysis suggests that the C-domain is not critical for the manifestation of specificity of the enzyme in the recognition of homologous RNAs. At the same time a significant influence of the C-terminal domain on the value of catalytic constant was shown. At the domain deletion the kcat value is lower by 152-fold. Conclusion. The C-terminal domain of LeuRSTT is evolutionarily acquired to enhance the rate of catalysis in the aminoacylation and editing reactions, and makes no significant contribution to the specificity of the enzyme in the recognition of tRNA.

  13. Expression, refolding, and characterization of a small laccase from Thermus thermophilus HJ6.

    Science.gov (United States)

    Kim, Han-Woo; Lee, So-Yeong; Park, Hyun; Jeon, Sung-Jong

    2015-10-01

    An open reading frame of the Thermus thermophilus HJ6 hypothetical laccase, which composed of 729 bases, was cloned and expressed as a fusion protein with six histidine residues in Escherichia coli SoluBL21™ cells. The resulting insoluble bodies were separated from cellular debris by centrifugation and solubilized with 6M guanidine HCl. The solubilized protein was refolded by a simple on-column refolding procedure using Ni-chelation affinity chromatography and then the refolded protein was purified by gel filtration chromatography. It showed a single band with a molecular mass of 27kDa in SDS-PAGE. The results from UV-visible absorption and electron paramagnetic resonance (EPR) analysis suggested that the enzyme had the typical copper sites, type-1, 2, and 3 Cu(II) of laccase. The purified enzyme exhibited the laccase activity with the optimal catalytic temperature at 75°C. The optimum pH for the oxidation of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and syringaldazine was 4.5 and 6.0, respectively. The recombinant protein showed high thermostability, and the half-life of heat inactivation was about 50min at 85°C. The enzyme oxidized various known laccase substrates, its lowest Km value being for syringaldazine, highest kcat value for guaiacol, and highest kcat/Km for 2,6-dimethoxy-phenol. The enzyme reaction was strongly inhibited by the metal chelators and the thiol compounds. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Properties and crystal structure of methylenetetrahydrofolate reductase from Thermus thermophilus HB8.

    Directory of Open Access Journals (Sweden)

    Sayaka Igari

    Full Text Available BACKGROUND: Methylenetetrahydrofolate reductase (MTHFR is one of the enzymes involved in homocysteine metabolism. Despite considerable genetic and clinical attention, the reaction mechanism and regulation of this enzyme are not fully understood because of difficult production and poor stability. While recombinant enzymes from thermophilic organisms are often stable and easy to prepare, properties of thermostable MTHFRs have not yet been reported. METHODOLOGY/PRINCIPAL FINDINGS: MTHFR from Thermus thermophilus HB8, a homologue of Escherichia coli MetF, has been expressed in E. coli and purified. The purified MTHFR was chiefly obtained as a heterodimer of apo- and holo-subunits, that is, one flavin adenine dinucleotide (FAD prosthetic group bound per dimer. The crystal structure of the holo-subunit was quite similar to the β(8α(8 barrel of E. coli MTHFR, while that of the apo-subunit was a previously unobserved closed form. In addition, the intersubunit interface of the dimer in the crystals was different from any of the subunit interfaces of the tetramer of E. coli MTHFR. Free FAD could be incorporated into the apo-subunit of the purified Thermus enzyme after purification, forming a homodimer of holo-subunits. Comparison of the crystal structures of the heterodimer and the homodimer revealed different intersubunit interfaces, indicating a large conformational change upon FAD binding. Most of the biochemical properties of the heterodimer and the homodimer were the same, except that the homodimer showed ≈50% activity per FAD-bound subunit in folate-dependent reactions. CONCLUSIONS/SIGNIFICANCE: The different intersubunit interfaces and rearrangement of subunits of Thermus MTHFR may be related to human enzyme properties, such as the allosteric regulation by S-adenosylmethionine and the enhanced instability of the Ala222Val mutant upon loss of FAD. Whereas E. coli MTHFR was the only structural model for human MTHFR to date, our findings suggest

  15. Cloning, overexpression and characterization of a thermostable pullulanase from Thermus thermophilus HB27.

    Science.gov (United States)

    Wu, Huawei; Yu, Xinxin; Chen, Libing; Wu, Guangxu

    2014-03-01

    A gene encoding a special type of pullulanase from Thermus thermophilus HB27 (TTHpu) was cloned. It has an open reading frame of 1428bp encoding a mature protein with a molecular mass of 52kDa. The gene was expressed in Escherichia coli using pHsh and pET28a vectors. The pHsh expression system produced a 3.6-fold higher recombinant pullulanase than pET28a. The recombinant TTHpu was purified to homogeneity by heat treatment and Ni-NTA affinity chromatography. The purified TTHpu exhibited highest activity at pH 6.5 and 70°C. More than 90% activity was retained after incubation at 60-70°C for 2h and the half-life was 2h at 80°C. The stability of the enzyme was in a pH range from 6.0 to 8.0. Manganese at 5mM enhanced its activity up to 298%. The Km and Vmax for the enzyme activity on pullulan were 0.0031mgmL(-1) and 23.8μmolmin(-1), respectively. Unlike the most of pullulan-hydrolyzing enzymes described to date, this enzyme can attack α-1,6- and α-1,4-glycosidic linkages in pullulan, and produce a mixture of maltotriose, maltose and glucose. The enzyme could be further employed for industrial saccharification of starch. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Insight into the transition between the open and closed conformations of Thermus thermophilus carboxypeptidase.

    Science.gov (United States)

    Okai, Masahiko; Yamamura, Akihiro; Hayakawa, Kou; Tsutsui, Shiho; Miyazono, Ken-Ichi; Lee, Woo-Cheol; Nagata, Koji; Inoue, Yumiko; Tanokura, Masaru

    2017-03-18

    Carboxypeptidase cleaves the C-terminal amino acid residue from proteins and peptides. Here, we report the functional and structural characterizations of carboxypeptidase belonging to the M32 family from the thermophilic bacterium Thermus thermophilus HB8 (TthCP). TthCP exhibits a relatively broad specificity for both hydrophilic (neutral and basic) and hydrophobic (aliphatic and aromatic) residues at the C-terminus and shows optimal activity in the temperature range of 75-80 °C and in the pH range of 6.8-7.2. Enzyme activity was significantly enhanced by cobalt or cadmium and was moderately inhibited by Tris at 25 °C. We also determined the crystal structure of TthCP at 2.6 Å resolution. Two dimer types of TthCP are present in the crystal. One type consists of two subunits in different states, open and closed, with a C(α) RMSD value of 2.2 Å; the other type consists of two subunits in the same open state. This structure enables us to compare the open and closed states of an M32 carboxypeptidase. The TthCP subunit can be divided into two domains, L and S, which are separated by a substrate-binding groove. The L and S domains in the open state are almost identical to those in the closed state, with C(α) RMSD values of 0.84 and 0.53 Å, respectively, suggesting that the transition between the open and closed states proceeds with a large hinge-bending motion. The superimposition between the closed states of TthCP and BsuCP, another M32 family member, revealed that most putative substrate-binding residues in the grooves are oriented in the same direction. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Conformational plasticity surrounding the active site of NADH oxidase from Thermus thermophilus.

    Science.gov (United States)

    Miletti, Teresa; Di Trani, Justin; Levros, Louis-Charles; Mittermaier, Anthony

    2015-07-01

    Biotechnological applications of enzymes can involve the use of these molecules under nonphysiological conditions. Thus, it is of interest to understand how environmental variables affect protein structure and dynamics and how this ultimately modulates enzyme function. NADH oxidase (NOX) from Thermus thermophilus exemplifies how enzyme activity can be tuned by reaction conditions, such as temperature, cofactor substitution, and the addition of cosolutes. This enzyme catalyzes the oxidation of reduced NAD(P)H to NAD(P)(+) with the concurrent reduction of O2 to H2O2, with relevance to biosensing applications. It is thermophilic, with an optimum temperature of approximately 65°C and sevenfold lower activity at 25°C. Moderate concentrations (≈1M) of urea and other chaotropes increase NOX activity by up to a factor of 2.5 at room temperature. Furthermore, it is a flavoprotein that accepts either FMN or the much larger FAD as cofactor. We have used nuclear magnetic resonance (NMR) titration and (15)N spin relaxation experiments together with isothermal titration calorimetry to study how NOX structure and dynamics are affected by changes in temperature, the addition of urea and the substitution of the FMN cofactor with FAD. The majority of signals from NOX are quite insensitive to changes in temperature, cosolute addition, and cofactor substitution. However, a small cluster of residues surrounding the active site shows significant changes. These residues are implicated in coupling changes in the solution conditions of the enzyme to changes in catalytic activity. © 2015 The Protein Society.

  18. Crystal Structure of the 30S Ribosomal Subunit from Thermus Thermophilus. Purification, Crystallization and Structure Determination

    Energy Technology Data Exchange (ETDEWEB)

    Clemons, William M.; Brodersen, Ditlev E.; McCutcheonn, John P.; May, Joanna L.C.; Carter, Andrew P.; Morgan-Warren, Robert J.; Wimberly, Brian T.; Ramakrishnan, Venki (MRC); (Utah); (MRC)

    2009-10-07

    We describe the crystallization and structure determination of the 30 S ribosomal subunit from Thermus thermophilus. Previous reports of crystals that diffracted to 10 {angstrom} resolution were used as a starting point to improve the quality of the diffraction. Eventually, ideas such as the addition of substrates or factors to eliminate conformational heterogeneity proved less important than attention to detail in yielding crystals that diffracted beyond 3 {angstrom} resolution. Despite improvements in technology and methodology in the last decade, the structure determination of the 30 S subunit presented some very challenging technical problems because of the size of the asymmetric unit, crystal variability and sensitivity to radiation damage. Some steps that were useful for determination of the atomic structure were: the use of anomalous scattering from the LIII edges of osmium and lutetium to obtain the necessary phasing signal; the use of tunable, third-generation synchrotron sources to obtain data of reasonable quality at high resolution; collection of derivative data precisely about a mirror plane to preserve small anomalous differences between Bijvoet mates despite extensive radiation damage and multi-crystal scaling; the pre-screening of crystals to ensure quality, isomorphism and the efficient use of scarce third-generation synchrotron time; pre-incubation of crystals in cobalt hexaammine to ensure isomorphism with other derivatives; and finally, the placement of proteins whose structures had been previously solved in isolation, in conjunction with biochemical data on protein-RNA interactions, to map out the architecture of the 30 S subunit prior to the construction of a detailed atomic-resolution model.

  19. Parallel pathways for nitrite reduction during anaerobic growth in Thermus thermophilus.

    Science.gov (United States)

    Alvarez, Laura; Bricio, Carlos; Hidalgo, Aurelio; Berenguer, José

    2014-04-01

    Respiratory reduction of nitrate and nitrite is encoded in Thermus thermophilus by the respective transferable gene clusters. Nitrate is reduced by a heterotetrameric nitrate reductase (Nar) encoded along transporters and regulatory signal transduction systems within the nitrate respiration conjugative element (NCE). The nitrite respiration cluster (nic) encodes homologues of nitrite reductase (Nir) and nitric oxide reductase (Nor). The expression and role of the nirSJM genes in nitrite respiration were analyzed. The three genes are expressed from two promoters, one (nirSp) producing a tricistronic mRNA under aerobic and anaerobic conditions and the other (nirJp) producing a bicistronic mRNA only under conditions of anoxia plus a nitrogen oxide. As for its nitrite reductase homologues, NirS is expressed in the periplasm, has a covalently bound heme c, and conserves the heme d1 binding pocket. NirJ is a cytoplasmic protein likely required for heme d1 synthesis and NirS maturation. NirM is a soluble periplasmic homologue of cytochrome c552. Mutants defective in nirS show normal anaerobic growth with nitrite and nitrate, supporting the existence of an alternative Nir in the cells. Gene knockout analysis of different candidate genes did not allow us to identify this alternative Nir protein but revealed the requirement for Nar in NirS-dependent and NirS-independent nitrite reduction. As the likely role for Nar in the process is in electron transport through its additional cytochrome c periplasmic subunit (NarC), we concluded all the Nir activity takes place in the periplasm by parallel pathways.

  20. Properties and Crystal Structure of Methylenetetrahydrofolate Reductase from Thermus thermophilus HB8

    Science.gov (United States)

    Igari, Sayaka; Ohtaki, Akashi; Yamanaka, Yasuaki; Sato, Yuichi; Yohda, Masafumi; Odaka, Masafumi; Noguchi, Keiichi; Yamada, Kazuhiro

    2011-01-01

    Background Methylenetetrahydrofolate reductase (MTHFR) is one of the enzymes involved in homocysteine metabolism. Despite considerable genetic and clinical attention, the reaction mechanism and regulation of this enzyme are not fully understood because of difficult production and poor stability. While recombinant enzymes from thermophilic organisms are often stable and easy to prepare, properties of thermostable MTHFRs have not yet been reported. Methodology/Principal Findings MTHFR from Thermus thermophilus HB8, a homologue of Escherichia coli MetF, has been expressed in E. coli and purified. The purified MTHFR was chiefly obtained as a heterodimer of apo- and holo-subunits, that is, one flavin adenine dinucleotide (FAD) prosthetic group bound per dimer. The crystal structure of the holo-subunit was quite similar to the β8α8 barrel of E. coli MTHFR, while that of the apo-subunit was a previously unobserved closed form. In addition, the intersubunit interface of the dimer in the crystals was different from any of the subunit interfaces of the tetramer of E. coli MTHFR. Free FAD could be incorporated into the apo-subunit of the purified Thermus enzyme after purification, forming a homodimer of holo-subunits. Comparison of the crystal structures of the heterodimer and the homodimer revealed different intersubunit interfaces, indicating a large conformational change upon FAD binding. Most of the biochemical properties of the heterodimer and the homodimer were the same, except that the homodimer showed ≈50% activity per FAD-bound subunit in folate-dependent reactions. Conclusions/Significance The different intersubunit interfaces and rearrangement of subunits of Thermus MTHFR may be related to human enzyme properties, such as the allosteric regulation by S-adenosylmethionine and the enhanced instability of the Ala222Val mutant upon loss of FAD. Whereas E. coli MTHFR was the only structural model for human MTHFR to date, our findings suggest that Thermus MTHFR will

  1. Omp85Tt from Thermus thermophilus HB27: an Ancestral Type of the Omp85 Protein Family▿

    Science.gov (United States)

    Nesper, Jutta; Brosig, Alexander; Ringler, Philippe; Patel, Geetika J.; Müller, Shirley A.; Kleinschmidt, Jörg H.; Boos, Winfried; Diederichs, Kay; Welte, Wolfram

    2008-01-01

    Proteins belonging to the Omp85 family are involved in the assembly of β-barrel outer membrane proteins or in the translocation of proteins across the outer membrane in bacteria, mitochondria, and chloroplasts. The cell envelope of the thermophilic bacterium Thermus thermophilus HB27 is multilayered, including an outer membrane that is not well characterized. Neither the precise lipid composition nor much about integral membrane proteins is known. The genome of HB27 encodes one Omp85-like protein, Omp85Tt, representing an ancestral type of this family. We overexpressed Omp85Tt in T. thermophilus and purified it from the native outer membranes. In the presence of detergent, purified Omp85Tt existed mainly as a monomer, composed of two stable protease-resistant modules. Circular dichroism spectroscopy indicated predominantly β-sheet secondary structure. Electron microscopy of negatively stained lipid-embedded Omp85Tt revealed ring-like structures with a central cavity of ∼1.5 nm in diameter. Single-channel conductance recordings indicated that Omp85Tt forms ion channels with two different conducting states, characterized by conductances of ∼0.4 nS and ∼0.65 nS, respectively. PMID:18456816

  2. Omp85(Tt) from Thermus thermophilus HB27: an ancestral type of the Omp85 protein family.

    Science.gov (United States)

    Nesper, Jutta; Brosig, Alexander; Ringler, Philippe; Patel, Geetika J; Müller, Shirley A; Kleinschmidt, Jörg H; Boos, Winfried; Diederichs, Kay; Welte, Wolfram

    2008-07-01

    Proteins belonging to the Omp85 family are involved in the assembly of beta-barrel outer membrane proteins or in the translocation of proteins across the outer membrane in bacteria, mitochondria, and chloroplasts. The cell envelope of the thermophilic bacterium Thermus thermophilus HB27 is multilayered, including an outer membrane that is not well characterized. Neither the precise lipid composition nor much about integral membrane proteins is known. The genome of HB27 encodes one Omp85-like protein, Omp85(Tt), representing an ancestral type of this family. We overexpressed Omp85(Tt) in T. thermophilus and purified it from the native outer membranes. In the presence of detergent, purified Omp85(Tt) existed mainly as a monomer, composed of two stable protease-resistant modules. Circular dichroism spectroscopy indicated predominantly beta-sheet secondary structure. Electron microscopy of negatively stained lipid-embedded Omp85(Tt) revealed ring-like structures with a central cavity of approximately 1.5 nm in diameter. Single-channel conductance recordings indicated that Omp85(Tt) forms ion channels with two different conducting states, characterized by conductances of approximately 0.4 nS and approximately 0.65 nS, respectively.

  3. Thermus thermophilus as source of thermozymes for biotechnological applications: homologous expression and biochemical characterization of an α-galactosidase.

    Science.gov (United States)

    Aulitto, Martina; Fusco, Salvatore; Fiorentino, Gabriella; Limauro, Danila; Pedone, Emilia; Bartolucci, Simonetta; Contursi, Patrizia

    2017-02-13

    The genus Thermus, which has been considered for a long time as a fruitful source of biotechnological relevant enzymes, has emerged more recently as suitable host to overproduce thermozymes. Among these, α-galactosidases are widely used in several industrial bioprocesses that require high working temperatures and for which thermostable variants offer considerable advantages over their thermolabile counterparts. Thermus thermophilus HB27 strain was used for the homologous expression of the TTP0072 gene encoding for an α-galactosidase (TtGalA). Interestingly, a soluble and active histidine-tagged enzyme was produced in larger amounts (5 mg/L) in this thermophilic host than in Escherichia coli (0.5 mg/L). The purified recombinant enzyme showed an optimal activity at 90 °C and retained more than 40% of activity over a broad range of pH (from 5 to 8). TtGalA is among the most thermoactive and thermostable α-galactosidases discovered so far, thus pointing to T. thermophilus as cell factory for the recombinant production of biocatalysts active at temperature values over 90 °C.

  4. Novel stand-alone RAM domain protein-mediated catalytic control of anthranilate phosphoribosyltransferase in tryptophan biosynthesis in Thermus thermophilus.

    Science.gov (United States)

    Kubota, Tetsuo; Matsushita, Hajime; Tomita, Takeo; Kosono, Saori; Yoshida, Minoru; Kuzuyama, Tomohisa; Nishiyama, Makoto

    2017-01-01

    Regulation of amino acid metabolism (RAM) domains are widely distributed among prokaryotes. In most cases, a RAM domain fuses with a DNA-binding domain to act as a transcriptional regulator. The extremely thermophilic bacterium, Thermus thermophilus, only carries a single gene encoding a RAM domain-containing protein on its genome. This protein is a stand-alone RAM domain protein (SraA) lacking a DNA-binding domain. Therefore, we hypothesized that SraA, which senses amino acids through its RAM domain, may interact with other proteins to modify its functions. In the present study, we identified anthranilate phosphoribosyltransferase (AnPRT), the second enzyme in the tryptophan biosynthetic pathway, as a partner protein that interacted with SraA in T. thermophilus. In the presence of tryptophan, SraA was assembled to a decamer and exhibited the ability to form a stable hetero-complex with AnPRT. An enzyme assay revealed that AnPRT was only inhibited by tryptophan in the presence of SraA. This result suggests a novel feedback control mechanism for tryptophan biosynthesis through an inter-RAM domain interaction in bacteria.

  5. Identification and characterization of preferred DNA-binding sites for the Thermus thermophilus transcriptional regulator FadR.

    Directory of Open Access Journals (Sweden)

    Minwoo Lee

    Full Text Available One of the primary transcriptional regulators of fatty acid homeostasis in many prokaryotes is the protein FadR. To better understand its biological function in the extreme thermophile Thermus thermophilus HB8, we sought to first determine its preferred DNA-binding sequences in vitro using the combinatorial selection method Restriction Endonuclease Protection, Selection, and Amplification (REPSA and then use this information to bioinformatically identify potential regulated genes. REPSA determined a consensus FadR-binding sequence 5´-TTRNACYNRGTNYAA-3´, which was further characterized using quantitative electrophoretic mobility shift assays. With this information, a search of the T. thermophilus HB8 genome found multiple operons potentially regulated by FadR. Several of these were identified as encoding proteins involved in fatty acid biosynthesis and degradation; however, others were novel and not previously identified as targets of FadR. The role of FadR in regulating these genes was validated by physical and functional methods, as well as comparative genomic approaches to further characterize regulons in related organisms. Taken together, our study demonstrates that a systematic approach involving REPSA, biophysical characterization of protein-DNA binding, and bioinformatics can be used to postulate biological roles for potential transcriptional regulators.

  6. In vitro affinity of Deinococcus radiodurans MutS towards mismatched DNA exceeds that of its orthologues from Escherichia coli and Thermus thermophilus.

    Science.gov (United States)

    Banasik, Michał; Stanisławska-Sachadyn, Anna; Hildebrandt, Ewa; Sachadyn, Paweł

    2017-06-20

    The mismatch binding protein MutS is responsible for the recognition of mispaired and unpaired bases, which is the initial step in DNA repair. Among the MutS proteins most extensively studied in vitro are those derived from Thermus thermophilus, Thermus aquaticus and Escherichia coli. Here, we present the first report on the in vitro examination of DNA mismatch binding activity of MutS protein from Deinococcus radiodurans and confront this with the properties of those from E. coli and T. thermophilus. The analyses which included mobility gel-shift assay, colorimetric and qPCR estimation of MutS-bound DNA clearly showed that D. radiodurans MutS exhibited much higher affinity towards mismatched DNA in vitro than its counterparts from E. coli and T. thermophilus. In addition, D. radiodurans MutS displayed a significantly higher specificity of DNA mismatch binding than the two other orthologues. The specificity expressed as the ratio of mismatched to fully complementary DNA bound reached over 4 and 20-fold higher values for D. radiodurans than for T. thermophilus and E. coli MutS, respectively. The results demonstrate mainly the biotechnological potential of D. radiodurans MutS but the in vitro characteristics of the MutS orthologues could reflect substantial differences in DNA mismatch binding activities existing in vivo. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. The role of fructans on dental biofilm formation by Streptococcus sobrinus, Streptococcus mutans, Streptococcus gordonii and Actinomyces viscosus.

    Science.gov (United States)

    Rozen, R; Bachrach, G; Bronshteyn, M; Gedalia, I; Steinberg, D

    2001-02-20

    Dental plaque biofilm plays a pivotal role in the progression of dental diseases. Polysaccharides are of great importance in the ecology of the dental biofilm. We studied the effect of fructans, glucans and a mixture of both fructans and glucans, synthesized in situ by immobilized fructosyltransferase or glucosyltransferase, on the adhesion of Streptococcus sobrinus, Streptococcus mutans, Streptococcus gordonii and Actinomyces viscosus to hydroxyapatite beads coated with human saliva (sHA). The adhesion of A. viscosus to sHA was found to be fructan-dependent. Adhesion of both S. sobrinus and S. mutans was found to be mediated mainly by glucans, while the adhesion of S. gordonii was found to be both glucan- and fructan-dependent. Treatment with fructanase prior to A. viscosus adhesion resulted in a significant reduction in adhesion to sHA, while adhesion of S. sobrinus, S. mutans and S. gordonii was slightly influenced by fructanase treatment. Treatment with fructanase after adhesion of S. gordonii to sHA resulted in a significant reduction in their adhesion to sHA. Our results show that fructans may play a role in the adhesion and colonization of several cariogenic bacteria to sHA, thus contributing to the formation of dental plaque biofilm.

  8. In silico modeling of the type 2 IDI enzymes of Bacillus licheniformis, Pseudomonas stutzeri, Streptococcus pyogenes, and Staphylococcus aureus for virtual screening of potential inhibitors of this therapeutic target.

    Science.gov (United States)

    Torktaz, Ibrahim; Shahbani Zahiri, Hossein; Akbari Noghabi, Kambiz

    2013-02-01

    Isopentenyl diphosphate isomerase is an essential enzyme in those living organisms such as pathogenic strains of Streptococcus and Staphylococcus genera which rely on the Mevalonate pathway for the production of isoprenoids. The pathogens contain type 2 IDI in contrast to human that contains type 1 IDI. Therefore, the type 2 IDI may be a potential target for the therapy of some infectious diseases. In the current study, a virtual screening by docking was performed among 2000 chemicals from CoCoCo library to find a specific inhibitor for type 2 IDIs. To this end, the structures of the type 2 IDIs of Bacillus licheniformis, Pseudomonas stutzeri, Streptococcus pyogenes, and Staphylococcus aureus were molded using comparative modeling and Hidden Markov Model (HMM) based prediction. The predicted models were evaluated based on Q-mean and Prosa score. Molegro Virtual Docker with MolDock scoring function was used for measuring the binding affinity of the found inhibitor to the active site of the models. Also the inhibition effect of the compound was virtually tested on the crystallography-solved structures of the Sulfolobus shibatae and Thermus thermophilus type 2 IDIs as well as the Escherichia coli type 1 IDI. Finally, the inhibition effect of the found inhibitor was virtually tested on the human type 1 IDI. Interestingly, the results suggest that the inhibitor efficiently binds to and inhibits the bacterial IDIs especially the type 2 IDIs of pathogens while it is not inhibiting the human IDI. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Capsular Polysaccharide Expression in Commensal Streptococcus Species

    DEFF Research Database (Denmark)

    Skov Sørensen, Uffe B; Yao, Kaihu; Yang, Yonghong

    2016-01-01

    Expression of a capsular polysaccharide is considered a hallmark of most invasive species of bacteria, including Streptococcus pneumoniae, in which the capsule is among the principal virulence factors and is the basis for successful vaccines. Consequently, it was previously assumed that capsule...... biosynthesis (cps) loci in all strains tested. Truncated cps loci were detected in three strains of S. pseudopneumoniae, in 26% of S. mitis strains, and in a single S. oralis strain. The level of sequence identities of cps locus genes confirmed that the structural polymorphism of capsular polysaccharides in S....... pneumoniae evolved by import of cps fragments from commensal Streptococcus species, resulting in a mosaic of genes of different origins. The demonstrated antigenic identity of at least eight of the numerous capsular polysaccharide structures expressed by commensal streptococci with recognized serotypes of S...

  10. [Neonatal cellulitis caused by group B Streptococcus].

    Science.gov (United States)

    Breinig, S; Roques-Gineste, M; Marcoux, M-O; Bloom, M-C

    2012-10-01

    Dermohypodermitis (cellulitis) in newborn infants and in infants aged up to 3 months is uncommon and often not typical. Because group B Streptococcus is known to induce rapid life-threatening complications, early diagnosis leading to emergency treatment is of utmost importance. We report on the case of a 14-day-old girl, initially admitted for viral bronchiolitis with suspected bacterial pulmonary infection, in the absence of any cutaneous injury. The disease actually was cellulitis of the face, caused by group B Streptococcus. The baby presented with a severe septic clinical condition. Early treatment with antibiotics (intravenous amoxicillin for 10 days) allowed a favorable course, with rapid control of the sepsis and regression of the submandibular tumefaction. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  11. Streptococcus dysgalactiae endocarditis presenting as acute endophthalmitis

    Directory of Open Access Journals (Sweden)

    Angelina Su-Min Yong

    2012-02-01

    Full Text Available Endogenous endophthalmitis is a rare ocular infection affecting the vitreous and/or aqueous humours. It is associated with poor visual prognosis and its commonest endogenous aetiology is infective endocarditis. The causative organisms of endogenous endophthalmitis complicating endocarditis are mainly Group A or B streptococci. The identification of Group C and G streptococci such as Streptococcus dysgalactiae is comparatively uncommon and has only been reported in a few case reports or series. We therefore report a case of infective endocarditis caused by Streptococcus dysgalactiae first presenting with endogenous endophthalmitis, the most likely source being bilateral feet osteomyelitis in a patient with type I diabetes. The patient was treated with a course of intravenous benzylpenicillin, intravitreal antibiotics, bilateral below knee amputations and mitral valve replacement. She survived all surgical procedures and regained partial visual acuity in the affected eye.

  12. Primary psoas abscess due to Streptococcus milleri.

    Science.gov (United States)

    Bagul, Nitin B; Abeysekara, Abeywardana M S; Jacob, Sabu

    2008-02-26

    Primary Psoas abscess (PPA) is an infrequent clinical entity with obscure pathogenesis and vague clinical presentation. High index of clinical suspicion is required for the diagnosis of psoas abscess. We also emphasises the importance of bacteriological confirmation of microorganism involved, although Staphylococcus aureus remains the commonest pathogen. We report an extremely rare case of PPA caused by Streptococcus milleri. Only one case has been reported in literature so far.

  13. Streptococcus mutans, Caries and Simulation Models

    OpenAIRE

    Ouwehand, Arthur C.; Marika Björklund; Forssten, Sofia D.

    2010-01-01

    Dental caries and dental plaque are among the most common diseases worldwide, and are caused by a mixture of microorganisms and food debris. Specific types of acid-producing bacteria, especially Streptococcus mutans, colonize the dental surface and cause damage to the hard tooth structure in the presence of fermentable carbohydrates e.g., sucrose and fructose. This paper reviews the link between S. mutans and caries, as well as different simulation models that are available for studying carie...

  14. Primary psoas abscess due to Streptococcus milleri

    Directory of Open Access Journals (Sweden)

    Abeysekara Abeywardana MS

    2008-02-01

    Full Text Available Abstract Primary Psoas abscess (PPA is an infrequent clinical entity with obscure pathogenesis and vague clinical presentation. High index of clinical suspicion is required for the diagnosis of psoas abscess. We also emphasises the importance of bacteriological confirmation of microorganism involved, although Staphylococcus aureus remains the commonest pathogen. We report an extremely rare case of PPA caused by Streptococcus milleri. Only one case has been reported in literature so far.

  15. Phenotypic, Genotypic, and Antimicrobial Characteristics of Streptococcus halichoeri Isolates from Humans, Proposal To Rename Streptococcus halichoeri as Streptococcus halichoeri subsp. halichoeri, and Description of Streptococcus halichoeri subsp. hominis subsp. nov., a Bacterium Associated with Human Clinical Infections

    National Research Council Canada - National Science Library

    Shewmaker, P L; Whitney, A M; Humrighouse, B W

    2016-01-01

    Phenotypic, genotypic, and antimicrobial characteristics of six phenotypically distinct human clinical isolates that most closely resembled the type strain of Streptococcus halichoeri isolated from a seal are presented...

  16. Invasive Streptococcus viridans sphenoethmoiditis leading to an orbital apex syndrome

    National Research Council Canada - National Science Library

    Lance Bodily; Jenny Yu; Dante Sorrentino; Barton Branstetter

    2017-01-01

    ...: An unusual case of infectious orbital apex syndrome due to contiguous spread of Streptococcus viridans sphenoethmoiditis in a hospitalized, immunosuppressed patient with acute myelogenous leukemia is presented...

  17. Resistance patterns of Streptococcus pneumoniae isolated from the ...

    African Journals Online (AJOL)

    Resistance patterns of Streptococcus pneumoniae isolated from the upper respiratory tract of persons attending various clinics of a University Teaching Hospital in Lagos, Nigeria - a preliminary study.

  18. Consideraciones sobre elaislamiento en exudados vaginales de Streptococcus morbillorum

    Directory of Open Access Journals (Sweden)

    J.M. F. Egido

    1995-06-01

    Full Text Available De el estúdio de 195 exudados vaginales enviados por el Servicio de Ginecologia de este hospital, durante el período 1988-1990, hemos seleccionado aquellos en los que el cultivo fue positivo para estreptococos, 58 (30% de los cuales 26 (44.8% correspondia a Streptococcus morbillorum, 9 (15.5% a Gardnerella vaginalis, 5 (8.6% a Enterococcus faecalis-durans, y a Streptococcus agalactiae, 3 (5.1% a Streptococcus mitis y Streptococcus mitis, 2 (3-4% a Streptococcus bovis y Streptococcus cremoris y 1 (1.7% a Streptococcus salivarius, Streptococcus equinus y Strptococcus sanguis II respectivamente. En todos los casos se observo antecedentes de actuacción medico- quirurjica en el tracto genital, y en el 52.8% de los casos fuô concomitante con el diagnostico clinico-micologico de candidiasis vaginal. La ideittificaccion bacteriologica se realizo mediante el sistema API 20 STREP (sistema api bioMêríeux GmbH, Nütingen, Alemania dando un patron tipico ("excelente identificacción" para el Streptococcus morbillorum.

  19. MALDI-TOF mass spectrometry for differentiation between Streptococcus pneumoniae and Streptococcus pseudopneumoniae.

    Science.gov (United States)

    van Prehn, Joffrey; van Veen, Suzanne Q; Schelfaut, Jacqueline J G; Wessels, Els

    2016-05-01

    We compared the Vitek MS and Microflex MALDI-TOF mass spectrometry platform for species differentiation within the Streptococcus mitis group with PCR assays targeted at lytA, Spn9802, and recA as reference standard. The Vitek MS correctly identified 10/11 Streptococcus pneumoniae, 13/13 Streptococcus pseudopneumoniae, and 12/13 S. mitis/oralis. The Microflex correctly identified 9/11 S. pneumoniae, 0/13 S. pseudopneumoniae, and 13/13 S. mitis/oralis. MALDI-TOF is a powerful tool for species determination within the mitis group. Diagnostic accuracy varies depending on platform and database used. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  20. Genomics, evolution, and molecular epidemiology of the Streptococcus bovis/Streptococcus equinus complex (SBSEC).

    Science.gov (United States)

    Jans, Christoph; Meile, Leo; Lacroix, Christophe; Stevens, Marc J A

    2015-07-01

    The Streptococcus bovis/Streptococcus equinus complex (SBSEC) is a group of human and animal derived streptococci that are commensals (rumen and gastrointestinal tract), opportunistic pathogens or food fermentation associates. The classification of SBSEC has undergone massive changes and currently comprises 7 (sub)species grouped into four branches based on sequences identities: the Streptococcus gallolyticus, the Streptococcus equinus, the Streptococcus infantarius and the Streptococcus alactolyticus branch. In animals, SBSEC are causative agents for ruminal acidosis, potentially laminitis and infective endocarditis (IE). In humans, a strong association was established between bacteraemia, IE and colorectal cancer. Especially the SBSEC-species S. gallolyticus subsp. gallolyticus is an emerging pathogen for IE and prosthetic joint infections. S. gallolyticus subsp. pasteurianus and the S. infantarius branch are further associated with biliary and urinary tract infections. Knowledge on pathogenic mechanisms is so far limited to colonization factors such as pili and biofilm formation. Certain strain variants of S. gallolyticus subsp. macedonicus and S. infantarius subsp. infantarius are associated with traditional dairy and plant-based food fermentations and display traits suggesting safety. However, due to their close relationship to virulent strains, their use in food fermentation has to be critically assessed. Additionally, implementing accurate and up-to-date taxonomy is critical to enable appropriate treatment of patients and risk assessment of species and strains via recently developed multilocus sequence typing schemes to enable comparative global epidemiology. Comparative genomics revealed that SBSEC strains harbour genomics islands (GI) that seem acquired from other streptococci by horizontal gene transfer. In case of virulent strains these GI frequently encode putative virulence factors, in strains from food fermentation the GI encode functions that are

  1. Atomic level description of the domain closure in a dimeric enzyme: thermus thermophilus 3-isopropylmalate dehydrogenase.

    Science.gov (United States)

    Gráczer, Éva; Merli, Angelo; Singh, Rajesh Kumar; Karuppasamy, Manikandan; Závodszky, Péter; Weiss, Manfred S; Vas, Mária

    2011-05-01

    The domain closure associated with the catalytic cycle is described at an atomic level, based on pairwise comparison of the X-ray structures of homodimeric Thermus thermophilus isopropylmalate dehydrogenase (IPMDH), and on their detailed molecular graphical analysis. The structures of the apo-form without substrate and in complex with the divalent metal-ion to 1.8 Å resolution, in complexes with both Mn(2+) and 3-isopropylmalate (IPM), as well as with both Mn(2+) and NADH, were determined at resolutions ranging from 2.0 to 2.5 Å. Single crystal microspectrophotometric measurements demonstrated the presence of a functionally competent protein conformation in the crystal grown in the presence of Mn(2+) and IPM. Structural comparison of the various complexes clearly revealed the relative movement of the two domains within each subunit and allowed the identification of two hinges at the interdomain region: hinge 1 between αd and βF as well as hinge 2 between αh and βE. A detailed analysis of the atomic contacts of the conserved amino acid side-chains suggests a possible operational mechanism of these molecular hinges upon the action of the substrates. The interactions of the protein with Mn(2+) and IPM are mainly responsible for the domain closure: upon binding into the cleft of the interdomain region, the substrate IPM induces a relative movement of the secondary structural elements βE, βF, βG, αd and αh. A further special feature of the conformational change is the movement of the loop bearing the amino acid Tyr139 that precedes the interacting arm of the subunit. The tyrosyl ring rotates and moves by at least 5 Å upon IPM-binding. Thereby, new hydrophobic interactions are formed above the buried isopropyl-group of IPM. Domain closure is then completed only through subunit interactions: a loop of one subunit that is inserted into the interdomain cavity of the other subunit extends the area with the hydrophobic interactions, providing an example of the

  2. In silico assessment of virulence factors in strains of Streptococcus oralis and Streptococcus mitis isolated from patients with Infective Endocarditis

    DEFF Research Database (Denmark)

    Rasmussen, Louise H.; Iversen, Katrine Højholt; Dargis, Rimtas

    2017-01-01

    Streptococcus oralis and Streptococcus mitis belong to the Mitis group, which are mostly commensals in the human oral cavity. Even though S. oralis and S. mitis are oral commensals, they can be opportunistic pathogens causing infective endocarditis. A recent taxonomic re-evaluation of the Mitis...... group has embedded the species Streptococcus tigurinus and Streptococcus dentisani into the species S. oralis as subspecies. In this study, the distribution of virulence factors that contribute to bacterial immune evasion, colonization and adhesion was assessed in clinical strains of S. oralis (subsp...

  3. Occurrence of Transsulfuration in Synthesis of l-Homocysteine in an Extremely Thermophilic Bacterium, Thermus thermophilus HB8

    Science.gov (United States)

    Yamagata, Shuzo; Ichioka, Kazuhito; Goto, Koji; Mizuno, Yasuko; Iwama, Tomonori

    2001-01-01

    A cell extract of an extremely thermophilic bacterium, Thermus thermophilus HB8, cultured in a synthetic medium catalyzed cystathionine γ-synthesis with O-acetyl-l-homoserine and l-cysteine as substrates but not β-synthesis with dl-homocysteine and l-serine (or O-acetyl-l-serine). The amounts of synthesized enzymes metabolizing sulfur-containing amino acids were estimated by determining their catalytic activities in cell extracts. The syntheses of cysthathionine β-lyase (EC 4.4.1.8) and O-acetyl-l-serine sulfhydrylase (EC 4.2.99.8) were markedly repressed by l-methionine supplemented to the medium. l-Cysteine and glutathione, both at 0.5 mM, added to the medium as the sole sulfur source repressed the synthesis of O-acetylserine sulfhydrylase by 55 and 73%, respectively, confirming that this enzyme functions as a cysteine synthase. Methionine employed at 1 to 5 mM in the same way derepressed the synthesis of O-acetylserine sulfhydrylase 2.1- to 2.5-fold. A method for assaying a low concentration of sulfide (0.01 to 0.05 mM) liberated from homocysteine by determining cysteine synthesized with it in the presence of excess amounts of O-acetylserine and a purified preparation of the sulfhydrylase was established. The extract of cells catalyzed the homocysteine γ-lyase reaction, with a specific activity of 5 to 7 nmol/min/mg of protein, but not the methionine γ-lyase reaction. These results suggested that cysteine was also synthesized under the conditions employed by the catalysis of O-acetylserine sulfhydrylase using sulfur of homocysteine derived from methionine. Methionine inhibited O-acetylserine sulfhydrylase markedly. The effects of sulfur sources added to the medium on the synthesis of O-acetylhomoserine sulfhydrylase and the inhibition of the enzyme activity by methionine were mostly understood by assuming that the organism has two proteins having O-acetylhomoserine sulfhydrylase activity, one of which is cystathionine γ-synthase. Although it has been

  4. Occurrence and Evolution of the Paralogous Zinc Metalloproteases IgA1 Protease, ZmpB, ZmpC, and ZmpD in Streptococcus pneumoniae and Related Commensal Species

    Science.gov (United States)

    Bek-Thomsen, Malene; Poulsen, Knud; Kilian, Mogens

    2012-01-01

    ABSTRACT The distribution, genome location, and evolution of the four paralogous zinc metalloproteases, IgA1 protease, ZmpB, ZmpC, and ZmpD, in Streptococcus pneumoniae and related commensal species were studied by in silico analysis of whole genomes and by activity screening of 154 representatives of 20 species. ZmpB was ubiquitous in the Mitis and Salivarius groups of the genus Streptococcus and in the genera Gemella and Granulicatella, with the exception of a fragmented gene in Streptococcus thermophilus, the only species with a nonhuman habitat. IgA1 protease activity was observed in all members of S. pneumoniae, S. pseudopneumoniae, S. oralis, S. sanguinis, and Gemella haemolysans, was variably present in S. mitis and S. infantis, and absent in S. gordonii, S. parasanguinis, S. cristatus, S. oligofermentans, S. australis, S. peroris, and S. suis. Phylogenetic analysis of 297 zmp sequences and representative housekeeping genes provided evidence for an unprecedented selection for genetic diversification of the iga, zmpB, and zmpD genes in S. pneumoniae and evidence of very frequent intraspecies transfer of entire genes and combination of genes. Presumably due to their adaptation to a commensal lifestyle, largely unaffected by adaptive mucosal immune factors, the corresponding genes in commensal streptococci have remained conserved. The widespread distribution and significant sequence diversity indicate an ancient origin of the zinc metalloproteases predating the emergence of the humanoid species. zmpB, which appears to be the ancestral gene, subsequently duplicated and successfully diversified into distinct functions, is likely to serve an important but yet unknown housekeeping function associated with the human host. PMID:23033471

  5. Efficacy of some synthetic antibiotics on Streptococcus pneumoniae ...

    African Journals Online (AJOL)

    Effects of some synthetic antibiotics on Streptococcus pnemoniae and Proteus mirabilis isolated from cultured Clarias gariepinus, an important food fish raised in a concrete tank was carried out to ascertain their remedies on mortalities of the Clarias gariepinus adult fish. Streptococcus pnemoniae and Proteus mirabilis were ...

  6. Prevalence of group b Streptococcus colonization in antenatal ...

    African Journals Online (AJOL)

    97 antenatal clinic attendees were recruited in a study aimed to determine the prevalence of group B streptococcus (Streptococcus agalactiae) among pregnant women at the Queen Elizabeth Central Hospital, Blantyre. Participants were interviewed using a standard questionnaire to gather demographic and other relevant ...

  7. The isolation rate of Staphylococcus and Streptococcus pathogenic ...

    African Journals Online (AJOL)

    Staphylococcus and Streptococcus isolates are among the major pathogens causing different diseases in Ethiopia. The aim of this study was to determine the frequency of isolation and sensitivity pattern of Staphylococcus and Streptococcus against the commonly used antibiotics. A retrospective study was carried out in this ...

  8. Endocarditis caused by Streptococcus canis: an emerging zoonosis?

    Science.gov (United States)

    Lacave, Guillaume; Coutard, Aymeric; Troché, Gilles; Augusto, Sandrine; Pons, Stéphanie; Zuber, Benjamin; Laurent, Virginie; Amara, Marlène; Couzon, Brigitte; Bédos, Jean-Pierre; Pangon, Béatrice; Grimaldi, David

    2016-02-01

    We report a human case of infective endocarditis caused by Streptococcus canis. Identification was carried out from positive blood culture using mass spectrometry and SodA gene sequencing. S. canis related zoonotic invasive infections may have been previously underdiagnosed due to inadequate identification of group G Streptococcus species.

  9. Infection caused by vancomycin-resistant Streptococcus sanguis II.

    Science.gov (United States)

    Shlaes, D M; Marino, J; Jacobs, M R

    1984-01-01

    A patient with bacteremia caused by vancomycin-resistant Streptococcus sanguis II is presented. This rare occurrence suggests that vancomycin may not be a completely reliable antibiotic in the treatment of infections due to viridans species of the genus Streptococcus. Gram-positive isolates from blood and otherwise sterile body fluids should be tested for susceptibility to vancomycin. PMID:6732222

  10. Influence of pH on inhibition of Streptococcus mutans by Streptococcus oligofermentans.

    Science.gov (United States)

    Liu, Ying; Chu, Lei; Wu, Fei; Guo, Lili; Li, Mengci; Wang, Yinghui; Wu, Ligeng

    2014-02-01

    Streptococcus oligofermentans is a novel strain of oral streptococcus that can specifically inhibit the growth of Streptococcus mutans. The aims of this study were to assess the growth of S. oligofermentans and the ability of S. oligofermentans to inhibit growth of Streptococcus mutans at different pH values. Growth inhibition was investigated in vitro using an interspecies competition assay. The 4-aminoantipyine method was used to measure the initial production rate and the total yield of hydrogen peroxide in S. oligofermentans. S. oligofermentans grew best at pH 7.0 and showed the most pronounced inhibitory effect when it was inoculated earlier than S. mutans. In terms of the total yield and the initial production rate of hydrogen peroxide by S. oligofermentans, the effects of the different culture pH values were as follows: pH 7.0 > 6.5 > 6.0 > 7.5 > 5.5 = 8.0 (i.e. there was no significant difference between pH 5.5 and pH 8.0). Environmental pH and the sequence of inoculation significantly affected the ability of S. oligofermentans to inhibit the growth of S. mutans. The degree of inhibition may be attributed to the amount of hydrogen peroxide produced. © 2013 Eur J Oral Sci.

  11. Spring forward with improved Nile tilapia Oreochromis niloticus resistant to Streptococcus iniae and Streptococcus agalactiae IB

    Science.gov (United States)

    Tilapia aquaculture worldwide is valued around US $ 7 billion. Tilapia are an important source of protein for domestic (top 5 most consumed seafoods) and global food security. Two gram postitive bacteria, Streptococcus iniae and S. agalactiae, are responsible for billion dollar losses annually. Gen...

  12. Antimicrobial activity of vanadium chloroperoxidase on planktonic Streptococcus mutans cells and Streptococcus mutans biofilms

    NARCIS (Netherlands)

    Hoogenkamp, M.A.; Crielaard, W.; ten Cate, J.M.; Wever, R.; Hartog, A.F.; Renirie, R.

    2009-01-01

    The aim of this study was to investigate the antimicrobial activity of vanadium chloroperoxidase (VCPO) reaction products on planktonic and biofilm cellsof Streptococcus mutans C180-2. Planktonic and biofilm cells were incubated in a buffered reaction mixture containing VCPO, halide (either chloride

  13. Control of Glycolysis by Glyceraldehyde-3-Phosphate Dehydrogenase in Streptococcus cremoris and Streptococcus lactis

    NARCIS (Netherlands)

    POOLMAN, B; BOSMAN, B; KONINGS, WN

    1987-01-01

    The decreased response of the energy metabolism of lactose-starved Streptococcus cremoris upon readdition of lactose is caused by a decrease of the glycolytic activity. The decrease in glycolysis is accompanied by a decrease in the activities of glyceraldehyde-3-phosphate dehydrogenase and

  14. Identification of a rhodanese-like protein involved in thiouridine biosynthesis in Thermus thermophilus tRNA.

    Science.gov (United States)

    Shigi, Naoki; Asai, Shin-Ichi; Watanabe, Kimitsuna

    2016-12-01

    Incorporation of a sulfur atom into 2-thioribothymidine (s(2) T or 5-methyl-2-thiouridine) at position 54 in thermophile tRNA is accomplished by an elaborate system composed of many proteins which confers thermostability to the translation system. We identified ttuD (tRNA-two-thiouridine D) as a gene for the synthesis of s(2) T54 in Thermus thermophilus. The rhodanese-like protein TtuD enhances the activity of cysteine desulfurases and receives the persulfide generated by cysteine desulfurases in vitro. TtuD also enhances the formation of thiocarboxylated TtuB, the sulfur donor for the tRNA sulfurtransferase TtuA. Since cysteine desulfurases are the first enzymes in the synthesis of s(2) T and other sulfur-containing compounds, TtuD has a role to direct sulfur flow to s(2) T synthesis. © 2016 Federation of European Biochemical Societies.

  15. Streptococcus pneumoniae: the forgotten microorganism in neonatal sepsis.

    Science.gov (United States)

    Rodriguez, Beatriz Fernandez; Mascaraque, Luis Rubio; Fraile, Leticia Ruiz; Perez, Irene Cuadrado; Kuder, Krzysztof

    2015-06-01

    Streptococcus pneumoniae is a rarely cause of neonatal sepsis. Its prevalence is low but with a mortality of 50%. Measures to prevent Streptococcus agalactiae transmission could help to increase Invasive Pneumococcal Disease (IPD) in newborns. Transmission could be from mother intrapartum; or in those cases of late onset sepsis, the community carriers. Systematic vaccination with PCV-7 and PCV-13 has reduced IPD rates. We present a case of a newborn with no perinatal risk factors for infection. In the first 24 hours after surgery of an ovarian cyst, the patient started with bad general condition with fever and regular perfusion. Empiric antibiotic treatment was started. Streptococcus pneumoniae was isolated in blood culture. In neonatal sepsis, we always think in Streptococcus agalactiae. Streptococcus pneumoniae is rare but with a high morbidity and mortality. Systematic vaccination is a measure that has demonstrated a reduction in the incidence of Invasive pneumococcal disease.

  16. Delineation of Streptococcus dysgalactiae, its subspecies, and its clinical and phylogenetic relationship to Streptococcus pyogenes.

    Science.gov (United States)

    Jensen, Anders; Kilian, Mogens

    2012-01-01

    The taxonomic status and structure of Streptococcus dysgalactiae have been the object of much confusion. Bacteria belonging to this species are usually referred to as Lancefield group C or group G streptococci in clinical settings in spite of the fact that these terms lack precision and prevent recognition of the exact clinical relevance of these bacteria. The purpose of this study was to develop an improved basis for delineation and identification of the individual species of the pyogenic group of streptococci in the clinical microbiology laboratory, with a special focus on S. dysgalactiae. We critically reexamined the genetic relationships of the species S. dysgalactiae, Streptococcus pyogenes, Streptococcus canis, and Streptococcus equi, which may share Lancefield group antigens, by phylogenetic reconstruction based on multilocus sequence analysis (MLSA) and 16S rRNA gene sequences and by emm typing combined with phenotypic characterization. Analysis of concatenated sequences of seven genes previously used for examination of viridans streptococci distinguished robust and coherent clusters. S. dysgalactiae consists of two separate clusters consistent with the two recognized subspecies dysgalactiae and equisimilis. Both taxa share alleles with S. pyogenes in several housekeeping genes, which invalidates identification based on single-locus sequencing. S. dysgalactiae, S. canis, and S. pyogenes constitute a closely related branch within the genus Streptococcus indicative of recent descent from a common ancestor, while S. equi is highly divergent from other species of the pyogenic group streptococci. The results provide an improved basis for identification of clinically important pyogenic group streptococci and explain the overlapping spectrum of infections caused by the species associated with humans.

  17. The transjugation machinery of Thermus thermophilus: Identification of TdtA, an ATPase involved in DNA donation.

    Science.gov (United States)

    Blesa, Alba; Baquedano, Ignacio; Quintáns, Nieves G; Mata, Carlos P; Castón, José R; Berenguer, José

    2017-03-01

    In addition to natural competence, some Thermus thermophilus strains show a high rate of DNA transfer via direct cell-to-cell contact. The process is bidirectional and follows a two-step model where the donor cell actively pushes out DNA and the recipient cell employs the natural competence system to take up the DNA, in a hybrid transformation-dependent conjugation process (transjugation). While the DNA uptake machinery is well known as in other bacterial species that undergo transformation, the pushing step of transjugation remains to be characterized. Here we have searched for hypothetical DNA translocases putatively involved in the pushing step of transjugation. Among candidates encoded by T. thermophilus HB27, the TdtA protein was found to be required for DNA pushing but not for DNA pulling during transjugation, without affecting other cellular processes. Purified TdtA shows ATPase activity and oligomerizes as hexamers with a central opening that can accommodate double-stranded DNA. The tdtA gene was found to belong to a mobile 14 kbp-long DNA element inserted within the 3' end of a tRNA gene, flanked by 47 bp direct repeats. The insertion also encoded a homolog of bacteriophage site-specific recombinases and actively self-excised from the chromosome at high frequency to form an apparently non-replicative circular form. The insertion also encoded a type II restriction endonuclease and a NurA-like nuclease, whose activities were required for efficient transjugation. All these data support that TdtA belongs to a new type of Integrative and Conjugative Element which promotes the generalized and efficient transfer of genetic traits that could facilitate its co-selection among bacterial populations.

  18. The transjugation machinery of Thermus thermophilus: Identification of TdtA, an ATPase involved in DNA donation.

    Directory of Open Access Journals (Sweden)

    Alba Blesa

    2017-03-01

    Full Text Available In addition to natural competence, some Thermus thermophilus strains show a high rate of DNA transfer via direct cell-to-cell contact. The process is bidirectional and follows a two-step model where the donor cell actively pushes out DNA and the recipient cell employs the natural competence system to take up the DNA, in a hybrid transformation-dependent conjugation process (transjugation. While the DNA uptake machinery is well known as in other bacterial species that undergo transformation, the pushing step of transjugation remains to be characterized. Here we have searched for hypothetical DNA translocases putatively involved in the pushing step of transjugation. Among candidates encoded by T. thermophilus HB27, the TdtA protein was found to be required for DNA pushing but not for DNA pulling during transjugation, without affecting other cellular processes. Purified TdtA shows ATPase activity and oligomerizes as hexamers with a central opening that can accommodate double-stranded DNA. The tdtA gene was found to belong to a mobile 14 kbp-long DNA element inserted within the 3' end of a tRNA gene, flanked by 47 bp direct repeats. The insertion also encoded a homolog of bacteriophage site-specific recombinases and actively self-excised from the chromosome at high frequency to form an apparently non-replicative circular form. The insertion also encoded a type II restriction endonuclease and a NurA-like nuclease, whose activities were required for efficient transjugation. All these data support that TdtA belongs to a new type of Integrative and Conjugative Element which promotes the generalized and efficient transfer of genetic traits that could facilitate its co-selection among bacterial populations.

  19. Comparative genomics of Thermus thermophilus and Deinococcus radiodurans: divergent routes of adaptation to thermophily and radiation resistance

    Directory of Open Access Journals (Sweden)

    Daly Michael J

    2005-10-01

    Full Text Available Abstract Background Thermus thermophilus and Deinococcus radiodurans belong to a distinct bacterial clade but have remarkably different phenotypes. T. thermophilus is a thermophile, which is relatively sensitive to ionizing radiation and desiccation, whereas D. radiodurans is a mesophile, which is highly radiation- and desiccation-resistant. Here we present an in-depth comparison of the genomes of these two related but differently adapted bacteria. Results By reconstructing the evolution of Thermus and Deinococcus after the divergence from their common ancestor, we demonstrate a high level of post-divergence gene flux in both lineages. Various aspects of the adaptation to high temperature in Thermus can be attributed to horizontal gene transfer from archaea and thermophilic bacteria; many of the horizontally transferred genes are located on the single megaplasmid of Thermus. In addition, the Thermus lineage has lost a set of genes that are still present in Deinococcus and many other mesophilic bacteria but are not common among thermophiles. By contrast, Deinococcus seems to have acquired numerous genes related to stress response systems from various bacteria. A comparison of the distribution of orthologous genes among the four partitions of the Deinococcus genome and the two partitions of the Thermus genome reveals homology between the Thermus megaplasmid (pTT27 and Deinococcus megaplasmid (DR177. Conclusion After the radiation from their common ancestor, the Thermus and Deinococcus lineages have taken divergent paths toward their distinct lifestyles. In addition to extensive gene loss, Thermus seems to have acquired numerous genes from thermophiles, which likely was the decisive contribution to its thermophilic adaptation. By contrast, Deinococcus lost few genes but seems to have acquired many bacterial genes that apparently enhanced its ability to survive different kinds of environmental stresses. Notwithstanding the accumulation of

  20. Flexibility and enzyme activity of NADH oxidase from Thermus thermophilus in the presence of monovalent cations of Hofmeister series.

    Science.gov (United States)

    Tóth, Kamil; Sedlák, Erik; Sprinzl, Mathias; Zoldák, Gabriel

    2008-05-01

    Recently, we have shown that anions of Hofmeister series affect the enzyme activity through modulation of flexibility of its active site. The enzyme activity vs. anion position in Hofmeister series showed an unusual bell-shaped dependence. In the present work, six monovalent cations (Na(+), Gdm(+), NH(4)(+), Li(+), K(+) and Cs(+)) of Hofmeister series with chloride as a counterion have been studied in relation to activity and stability of flavoprotein NADH oxidase from Thermus thermophilus (NOX). With the exception of strongly chaotropic guanidinium cation, cations are significantly less effective in promoting the Hofmeister effect than anions mainly due to repulsive interactions of positive charges around the active site. Thermal denaturations of NOX reveal unfavorable electrostatic interaction at the protein surface that may be shielded to different extent by salts. Michaelis-Menten constants for NADH, accessibility of the active site as reflected by Stern-Volmer constants and activity of NOX at high cation concentrations (1-2 M) show bell-shaped dependences on cation position in Hofmeister series. Our analysis indicates that in the presence of kosmotropic cations the enzyme is more stable and possibly more rigid than in the presence of chaotropic cations. Molecular dynamic (MD) simulations of NOX showed that active site switches between open and closed conformations [J. Hritz, G. Zoldak, E. Sedlak, Cofactor assisted gating mechanism in the active site of NADH oxidase from Thermus thermophilus, Proteins 64 (2006) 465-476]. Enzyme activity, as well as substrate binding, can be regulated by the salt mediated perturbation of the balance between open and closed forms. We propose that compensating effect of accessibility and flexibility of the enzyme active site leads to bell-shaped dependence of the investigated parameters.

  1. [The effect of fluoride on adhesion of Streptococcus mutans and Streptococcus sanguis on the dental pure titanium surface].

    Science.gov (United States)

    Wang, Jue; Qiao, Guang-yan; Shen, Qing-ping; Gu, Kai-kai

    2015-04-01

    This study was to investigate the effect of fluoride on adhesion of Streptococcus mutans and Streptococcus sanguis on the dental pure titanium surface. The adhesion of Streptococcus mutans and Streptococcus sanguis on the dental pure titanium surface were examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay after soaked in artificial saliva containing different concentrations of sodium fluoride for 24 h. Then the surface roughness and surface morphology of the pure titanium were analyzed by atomic force microscope after bacterial adhesion experiments. The data was statistically analyzed by analysis of variance(ANOVA) with SPSS11.0 software package. After soaked in artificial saliva containing different concentrations of sodium fluoride for 24 h, the sequence of OD values showed the adhesion of Streptococcus mutans and Streptococcus sanguis on dental pure titanium surface was 0 g/L sanguis, surface roughness and surface morphology reveal that fluoride aggravates the corrosion of pure titanium, increases the surface roughness, and thus promots the adhesion of Streptococcus mutans and Streptococcus sanguis on the titanium surface.

  2. Pyopneumothorax secondary to Streptococcus milleri infection.

    Science.gov (United States)

    Che Rahim, Mohd Jazman; Mohammad, Nurashikin; Wan Ghazali, Wan Syamimee

    2016-11-23

    We report a case of a 46-year-old Malay woman with underlying hypothyroidism post thyroidectomy who presented with worsening breathlessness, orthopnoea, productive cough and left-sided pleuritic chest pain of 3 days duration. Chest X-ray on admission showed left-sided massive hydropneumothorax. Pleural tapping revealed empyema. A chest tube was inserted immediately. The culture of pleural fluid grew Streptococcus constellatus The patient was treated with antibiotics for a total of 6 weeks and underwent open thoracotomy and decortication during admission. Subsequently, her lung condition improved and there was no evidence of recurrence during follow-up. 2016 BMJ Publishing Group Ltd.

  3. Sodium/proton antiporter in Streptococcus faecalis.

    OpenAIRE

    Kakinuma, Y

    1987-01-01

    Streptococcus faecalis, like other bacteria, accumulates potassium ions and expels sodium ions. This paper is concerned with the pathway of sodium extrusion. Earlier studies (D.L. Heefner and F.M. Harold, Proc. Natl. Acad. Sci. USA 79:2798-2802, 1982) showed that sodium extrusion is effected by a primary, ATP-linked sodium pump. I report here that cells grown under conditions in which sodium ATPase is not induced can still expel sodium ions. This finding suggested the existence of an alternat...

  4. Acid tolerance mechanisms utilized by Streptococcus mutans

    Science.gov (United States)

    Matsui, Robert; Cvitkovitch, Dennis

    2010-01-01

    Since its discovery in 1924 by J Clarke, Streptococcus mutans has been the focus of rigorous research efforts due to its involvement in caries initiation and progression. Its ability to ferment a range of dietary carbohydrates can rapidly drop the external environmental pH, thereby making dental plaque inhabitable to many competing species and can ultimately lead to tooth decay. Acid production by this oral pathogen would prove suicidal if not for its remarkable ability to withstand the acid onslaught by utilizing a wide variety of highly evolved acid-tolerance mechanisms. The elucidation of these mechanisms will be discussed, serving as the focus of this review. PMID:20210551

  5. Ferrous iron transport in Streptococcus mutans

    Energy Technology Data Exchange (ETDEWEB)

    Evans, S.L.; Arcenaeux, J.E.L.; Byers, B.R.; Martin, M.E.; Aranha, H.

    1986-12-01

    Radioiron uptake from /sup 59/FeCl/sub 3/ by Streptococcus mutans OMZ176 was increased by anaerobiosis, sodium ascorbate, and phenazine methosulfate (PMS), although there was a 10-min lag before PMS stimulation was evident. The reductant ascorbate may have provided ferrous iron. The PMS was reduced by the cells, and the reduced PMS then may have generated ferrous iron for transport; reduced PMS also may have depleted dissolved oxygen. It was concluded that S. mutans transports only ferrous iron, utilizing reductants furnished by glucose metabolism to reduce iron prior to its uptake.

  6. Lactational mastitis caused by Streptococcus lactarius.

    Science.gov (United States)

    Tena, Daniel; Fernández, Cristina; López-Garrido, Beatriz; Pérez-Balsalobre, Mercedes; Losa, Cristina; Medina-Pascual, María José; Sáez-Nieto, Juan Antonio

    2016-08-01

    Human infections caused by Streptococcus lactarius have not been previously reported. In the present report, we describe a lactational mastitis caused by this organism. The infection occurred in a 28-year-old breast-feeding female, with a 10-days history of moderate pain on the right breast. The patient was cured after antibiotic treatment with levofloxacin for 21 days. Our case shows that S. lactarius should be considered as a cause of lactational mastitis. The introduction of molecular microbiology techniques can be extremely useful for knowing the implication of streptococci in lactational mastitis. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Necrotizing fasciitis caused by group A streptococcus

    Directory of Open Access Journals (Sweden)

    Mikić Dragan

    2002-01-01

    Full Text Available The first case of the confirmed necrotizing fasciitis caused by Group A Streptococcus in Yugoslavia was presented. Male patient, aged 28, in good health, suddenly developed symptoms and signs of severe infective syndrome and intensive pain in the axillary region. Parenteral antibiotic, substitution and supportive therapy was conducted along with the radical surgical excision of the necrotizing tissue. The patient did not develop streptococcal toxic shock syndrome thanks to the early established diagnosis and timely applied aggressive treatment. He was released from the hospital as completely cured two months after the admission.

  8. Diverse virulent pneumophages infect Streptococcus mitis.

    Directory of Open Access Journals (Sweden)

    Siham Ouennane

    Full Text Available Streptococcus mitis has emerged as one of the leading causes of bacterial endocarditis and is related to Streptococcus pneumoniae. Antibiotic resistance has also increased among strains of S. mitis and S. pneumoniae. Phages are being reinvestigated as alternatives to antibiotics for managing infections. In this study, the two virulent phages Cp-1 (Podoviridae and Dp-1 (Siphoviridae, previously isolated from S. pneumoniae, were found to also infect S. mitis. Microbiological assays showed that both pneumophages could not only replicate in S. mitis but also produced more visible plaques on this host. However, the burst size and phage adsorption data were lower in S. mitis as compared to S. pneumoniae. A comparison of the genomes of each phage grown on both hosts produced identical nucleotide sequences, confirming that the same phages infect both bacterial species. We also discovered that the genomic sequence of podophage Cp-1 of the Félix d'Hérelle collection is different than the previously reported sequence and thus renamed SOCP.

  9. Novel Regulatory Small RNAs in Streptococcus pyogenes

    Science.gov (United States)

    Tesorero, Rafael A.; Yu, Ning; Wright, Jordan O.; Svencionis, Juan P.; Cheng, Qiang; Kim, Jeong-Ho; Cho, Kyu Hong

    2013-01-01

    Streptococcus pyogenes (Group A Streptococcus or GAS) is a Gram-positive bacterial pathogen that has shown complex modes of regulation of its virulence factors to cause diverse diseases. Bacterial small RNAs are regarded as novel widespread regulators of gene expression in response to environmental signals. Recent studies have revealed that several small RNAs (sRNAs) have an important role in S. pyogenes physiology and pathogenesis by regulating gene expression at the translational level. To search for new sRNAs in S. pyogenes, we performed a genomewide analysis through computational prediction followed by experimental verification. To overcome the limitation of low accuracy in computational prediction, we employed a combination of three different computational algorithms (sRNAPredict, eQRNA and RNAz). A total of 45 candidates were chosen based on the computational analysis, and their transcription was analyzed by reverse-transcriptase PCR and Northern blot. Through this process, we discovered 7 putative novel trans-acting sRNAs. Their abundance varied between different growth phases, suggesting that their expression is influenced by environmental or internal signals. Further, to screen target mRNAs of an sRNA, we employed differential RNA sequencing analysis. This study provides a significant resource for future study of small RNAs and their roles in physiology and pathogenesis of S. pyogenes. PMID:23762235

  10. Septic arthritis due to Streptococcus sanguis.

    Science.gov (United States)

    Mandac, Inga; Prkacin, Ingrid; Matovinović, Mirjana Sabljar; Sustercić, Dunja

    2010-06-01

    Septic arthritis may represent a direct invasion of joint space by various microorganisms, including bacteria, viruses and fungi. Although any infectious agent may cause bacterial arthritis, bacterial pathogens are the most significant because of their rapidly destructive nature. We present a case of septic arthritis in a 56-year old male patient due to Streptococcus viridans which is member of the viridans group streptococci. Patient was admitted to Our Hospital presented as fever of unknown origin, losing more than 30 kg of body weight during couple of months, and anemia of chronic disease as paraneoplastic process. He had long history of arterial hypertension and stroke. There was swelling and pain of the right sternoclavicular joint and precordial systolic murmur in physical status. A large diagnostic panel has been made, computerized tomography (CT) of right sternoclavicular joint showed widening of periarticular soft tissue and loss of clavicular corticalis. Cytologic analysis of synovial fluid showed more than 90% of polymorphonuclear leukocytes. There were no crystals on microscopic examination and Gram stain of fluid was negative. Blood cultures were positive for S. sanguis and there was a consideration about possible periodontal disease. Stomatologic examination verified periapical ostitis and extraction of potential cause of infection has been done. Therapy with benzilpenicilline was followed by the gradual improvement of clinical and laboratory parameters. Although viridans group streptococci and Streptococcus sanguis in particular are rare causes of septic arthritis in native joints, they should be considered in the differential diagnosis of periodontal disease.

  11. Cloning of alpha- and beta-galactosidase genes from an extreme thermophile, Thermus strain T2, and their expression in Thermus thermophilus HB27.

    Science.gov (United States)

    Koyama, Y; Okamoto, S; Furukawa, K

    1990-01-01

    The genes encoding thermostable alpha- and beta-galactosidases from an extremely thermophilic bacterium, Thermus strain T2, were cloned in Escherichia coli. The alpha-galactosidase gene was located just downstream from the beta-galactosidase gene. The genes were introduced into Thermus thermophilus HB27 with the aid of Thermus cryptic plasmid pTT8, and beta-galactosidases were expressed constitutively. PMID:2167630

  12. Cloning of alpha- and beta-galactosidase genes from an extreme thermophile, Thermus strain T2, and their expression in Thermus thermophilus HB27.

    OpenAIRE

    Koyama, Y; Okamoto, S.; Furukawa, K.

    1990-01-01

    The genes encoding thermostable alpha- and beta-galactosidases from an extremely thermophilic bacterium, Thermus strain T2, were cloned in Escherichia coli. The alpha-galactosidase gene was located just downstream from the beta-galactosidase gene. The genes were introduced into Thermus thermophilus HB27 with the aid of Thermus cryptic plasmid pTT8, and beta-galactosidases were expressed constitutively.

  13. Liver abscess associated with an oral flora bacterium Streptococcus anginosus

    Directory of Open Access Journals (Sweden)

    Hava Yılmaz

    2012-03-01

    Full Text Available Viridans group Streptococcus, a bacterium of the oral flora has a low-virulence and rarely causes liver abscess. A 40-yearoldmale patient was admitted to the hospital complaining of high fever and malaise. A physical examination revealedpoor oral hygiene; there were caries on many teeth, and he had hepatomegaly. A hepatic abscess was identified inhis abdominal tomography. Streptococcus anginosus was isolated from the drainage material, and the bile ducts werenormal in his MRI cholangiography. An immunocompetent case of liver abscess caused by Streptococcus anginosusoriginated most probably from oral flora is presented here. J Microbiol Infect Dis 2012; 2(1:33-35

  14. Antibacterial synergistic effect of chlorhexidine and hydrogen peroxide against Streptococcus sobrinus, Streptococcus faecalis and Staphylococcus aureus.

    Science.gov (United States)

    Steinberg, D; Heling, I; Daniel, I; Ginsburg, I

    1999-02-01

    Chlorhexidine (CHX) and Hydrogen peroxide (HP) are potent antibacterial agents that are used in controlling dental plaque. However, both agents bear undesired side-effects. We have tested the hypothesis that an antibacterial synergistic effect can occur between the two agents against Streptococcus sobrinus, Streptococcus faecalis and Staphylococcus aureus. We have found that at several combinations of HP and CHX an antibacterial synergistic effect does occur, while at other combinations a on-significant synergism was noticed. No antagonism between the two agents was found in our experimental system. It can be postulated that the mechanism of this synergistic effect is via alteration of the bacterial cell-surface by CHX thereby allowing for an increased amount of HP to penetrate and to react with the intercellular organelles of the bacteria. These results suggest that CHX and HP can be of use in controlling the dental plaque in the oral cavity.

  15. Use of partial budgeting to determine the economic benefits of antibiotic treatment of chronic subclinical mastitis caused by Streptococcus uberis or Streptococcus dysgalactiae

    NARCIS (Netherlands)

    Swinkels, J.M.; Rooijendijk, J.G.A.; Zadoks, R.N.; Hogeveen, H.

    2005-01-01

    The economic effect of lactational antibiotic treatment of chronic subclinical intramammary infections due to Streptococcus uberis or Streptococcus dysgalactiae was explored by means of partial budgeting. Effects at cow level and herd level were modelled, including prevention of clinical mastitis

  16. Comparison of genes required for H2O2 resistance in Streptococcus gordonii and Streptococcus sanguinis

    Science.gov (United States)

    Xu, Yifan; Itzek, Andreas

    2014-01-01

    Hydrogen peroxide (H2O2) is produced by several members of the genus Streptococcus mainly through the pyruvate oxidase SpxB under aerobic growth conditions. The acute toxic nature of H2O2 raises the interesting question of how streptococci cope with intrinsically produced H2O2, which subsequently accumulates in the microenvironment and threatens the closely surrounding population. Here, we investigate the H2O2 susceptibility of oral Streptococcus gordonii and Streptococcus sanguinis and elucidate potential mechanisms of how they protect themselves from the deleterious effect of H2O2. Both organisms are considered primary colonizers and occupy the same intraoral niche making them potential targets for H2O2 produced by other species. We demonstrate that S. gordonii produces relatively more H2O2 and has a greater ability for resistance to H2O2 stress. Functional studies show that, unlike in Streptococcus pneumoniae, H2O2 resistance is not dependent on a functional SpxB and confirms the important role of the ferritin-like DNA-binding protein Dps. However, the observed increased H2O2 resistance of S. gordonii over S. sanguinis is likely to be caused by an oxidative stress protection machinery present even under anaerobic conditions, while S. sanguinis requires a longer period of time for adaptation. The ability to produce more H2O2 and be more resistant to H2O2 might aid S. gordonii in the competitive oral biofilm environment, since it is lower in abundance yet manages to survive quite efficiently in the oral biofilm. PMID:25280752

  17. Reappraisal of the taxonomy of Streptococcus suis serotypes 20, 22 and 26: Streptococcus parasuis sp. nov.

    Science.gov (United States)

    Nomoto, R; Maruyama, F; Ishida, S; Tohya, M; Sekizaki, T; Osawa, Ro

    2015-02-01

    In order to clarify the taxonomic position of serotypes 20, 22 and 26 of Streptococcus suis, biochemical and molecular genetic studies were performed on isolates (SUT-7, SUT-286(T), SUT-319, SUT-328 and SUT-380) reacted with specific antisera of serotypes 20, 22 or 26 from the saliva of healthy pigs as well as reference strains of serotypes 20, 22 and 26. Comparative recN gene sequencing showed high genetic relatedness among our isolates, but marked differences from the type strain S. suis NCTC 10234(T), i.e. 74.8-75.7 % sequence similarity. The genomic relatedness between the isolates and other strains of species of the genus Streptococcus, including S. suis, was calculated using the average nucleotide identity values of whole genome sequences, which indicated that serotypes 20, 22 and 26 should be removed taxonomically from S. suis and treated as a novel genomic species. Comparative sequence analysis revealed 99.0-100 % sequence similarities for the 16S rRNA genes between the reference strains of serotypes 20, 22 and 26, and our isolates. Isolate STU-286(T) had relatively high 16S rRNA gene sequence similarity with S. suis NCTC 10234(T) (98.8 %). SUT-286(T) could be distinguished from S. suis and other closely related species of the genus Streptococcus using biochemical tests. Due to its phylogenetic and phenotypic similarities to S. suis we propose naming the novel species Streptococcus parasuis sp. nov., with SUT-286(T) ( = JCM 30273(T) = DSM 29126(T)) as the type strain. © 2015 IUMS.

  18. Capsular Polysaccharide Expression in Commensal Streptococcus Species: Genetic and Antigenic Similarities to Streptococcus pneumoniae

    OpenAIRE

    Skov Sørensen, Uffe B.; Kaihu Yao; Yonghong Yang; Hervé Tettelin; Mogens Kilian

    2016-01-01

    ABSTRACT Expression of a capsular polysaccharide is considered a hallmark of most invasive species of bacteria, including Streptococcus pneumoniae, in which the capsule is among the principal virulence factors and is the basis for successful vaccines. Consequently, it was previously assumed that capsule production distinguishes S.?pneumoniae from closely related commensals of the mitis group streptococci. Based on antigenic and genetic analyses of 187 mitis group streptococci, including 90 re...

  19. Effect of nicotine on dual-species biofilms of Streptococcus mutans and Streptococcus sanguinis.

    Science.gov (United States)

    Li, Mingyun; Huang, Ruijie; Zhou, Xuedong; Zhang, Keke; Zheng, Xin; Gregory, Richard L

    2014-01-01

    Both Streptococcus mutans and Streptococcus sanguinis are normal bacterial inhabitants of dental plaque. Streptococcus mutans is the major agent causing dental caries. It has been well documented that nicotine affects the growth of S. mutans. This study investigated the effect of nicotine on mono- and dual-species growth of S. mutans and S. sanguinis. The results indicate that nicotine has no significant effect on S. sanguinis grown in either mono- or dual-species biofilms. However, nicotine significantly increased (P mutans in dual-species biofilm formation. In addition, the CFU level of S. sanguinis was higher than S. mutans without nicotine in the culture. With the addition of nicotine, the level of S. mutans biofilm was significantly enhanced as the nicotine concentration increased over the level of S. sanguinis in dual-species biofilm, and we also got the same result from the fluorescence in situ hybridization detecting the two bacteria grown in biofilm formation. The exopolysaccharide (EPS) of S. mutans has also been increased by the increasing nicotine concentration, while the EPS of S. sanguinis was decreased or inhibited by the affected nicotine. The data further confirm that nicotine is able to enhance the growth of S. mutans. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  20. Caries prevalence associated with Streptococcus mutans and Streptococcus sobrinus in Japanese schoolchildren.

    Science.gov (United States)

    Okada, Mitsugi; Kawamura, Makoto; Oda, Yuki; Yasuda, Rie; Kojima, Taro; Kurihara, Hidemi

    2012-09-01

    Streptococcus mutans and Streptococcus sobrinus are known to be associated with dental caries in humans. We used a polymerase chain reaction method to detect S. mutans and S. sobrinus in 128 Japanese schoolchildren and then compared their presence with the dental caries experience. Plaque samples were collected from all erupted tooth sites with a sterile toothbrush, and dental examinations were performed to determine the numbers of decayed and filled teeth in primary (dft) and permanent (DFT) dentition using the WHO caries diagnostic criteria. Fisher's PLSD test was employed to compare caries scores between combinations of the detected bacteria. Streptococcus mutans and S. sobrinus were present in 38.3% and 68.0%, respectively, whereas 14.8% were positive for S. mutans alone, 44.5% for S. sobrinus alone, and 23.5% for both S. mutans and S. sobrinus, with 17.2% negative for both. The DFT, dft, and total (DFT + dft) scores for subjects positive for both S. mutans and S. sobrinus were significantly higher than those positive for S. mutans alone (P mutans and S. sobrinus have a significant higher dental caries experience in both permanent and primary teeth as compared to those with S. mutans alone. © 2012 The Authors. International Journal of Paediatric Dentistry © 2012 BSPD, IAPD and Blackwell Publishing Ltd.

  1. Antimicrobial resistance in Staphylococcus aureus, Streptococcus uberis and Streptococcus dysgalactiae from dairy cows with mastitis.

    Science.gov (United States)

    McDougall, S; Hussein, H; Petrovski, K

    2014-03-01

    To determine the minimal inhibitory concentrations (MIC) of antimicrobials for common mastitis pathogens from dairy cows in New Zealand; and to assess the effect of source of the isolates, i.e. commercial veterinary laboratories or collected as part of research studies; the clinical status of the cow, i.e. subclinical or clinical mastitis; cow age and herd on the distribution of the MIC. Minimal inhibitory concentrations for Staphylococcus aureus (n=364), Streptococcus dysgalactiae (n=65) and Streptococcus uberis (n=102) isolated from milk samples from dairy cows were determined for a variety of antimicrobials using broth microdilution. Isolates of S. aureus were sourced from research studies from both subclinically (n=161) and clinically (n=104) affected cows, as well as from commercial veterinary laboratories (n=101); while all the streptococcal isolates were from commercial laboratories. Resistance was defined using the cut-points provided by the Clinical and Laboratory Standards Institute (CLSI). The distribution of MIC varied among the bacterial species for every antimicrobial tested (pStreptococcus isolates; therefore microbial identification and sensitivity testing would be beneficial when assessing treatment options. The source of the isolates affected the estimated MIC, suggesting that selection of isolates for monitoring of resistance requires care and that use of routine submissions to commercial laboratories to assess antimicrobial resistance patterns may result in biased estimates of prevalence of resistance.

  2. Iatrogenic streptococcus salivarius meningitis: a case report

    Directory of Open Access Journals (Sweden)

    Kristina Praper

    2017-11-01

    Full Text Available We present a case of a 28-year-old patient who underwent spinal anaesthesia for caesarean section, and developed meningitis, Streptococcus salivarius was isolated in the cerebrospinal fluid. The Viridans streptococci are a part of a normal human mouth flora, therefore the patient most likely developed iatrogenic meningitis due to droplet transmission of bacteria intrathecally. We discuss etiology, pathogenesis, clinical presentation, diagnostic tools, treatment and prognosis of meningitis afer intrathecal procedures and we emphasize the importance of strict aseptic technique while performing neuraxial procedures. Iatrogenic meningitis should be considered as a possible differential diagnosis in patients who present with symptoms and signs of meningitis after neuraxial blockade.

  3. Streptococcus pneumoniae, mecanismos de resistencia antimicrobiana

    Directory of Open Access Journals (Sweden)

    Amauri Noda Albelo

    2011-09-01

    Full Text Available El Streptococcus pneumoniae, principal agente causal de la neumonía comunitaria, líder en la etiología de la otitis media y la meningitis, en las últimas 3 décadas ha incrementado, de manera importante, su resistencia a los agentes terapéuticos más utilizados, como los betalactámicos, macrólidos, azálidos y fluroquinolonas. La versatilidad adaptativa del microorganismo le ha permitido crear mecanismos capaces de sobreponerse a cualquiera de estas agresiones terapéuticas con un grado variable de eficacia. Se realiza una revisión de los mecanismos más importantes implicados en la adquisición de resistencia antimicrobiana por S. pneumoniae, y se precisan algunos de los factores de riesgo implicados en infección por S. pneumoniae resistente.

  4. Streptococcus agalactiae infection in tilapia (Oreochromis niloticus

    Directory of Open Access Journals (Sweden)

    Suanyuk, N.

    2005-02-01

    Full Text Available Streptococcus agalactiae was isolated from cultured tilapia in Surat Thani province. Isolates were Gram-positive cocci, catalase negative, alpha-haemolytic and serogroup B. Streptococcal-infected fish showed various swimming abnormalities such as swimming on their side, erratic surface or bottom swimming including serpentine movement, exophthalmia and opacity. Internally, splenomegaly, ascites as well as pale liver discoloration were observed. Fish experimentally infected by peritoneal injection using 101 -108 CFU/ fish showed 20-90% mortality within 10 days and the LD50 was 3.60x101 - 1.72x107 CFU. Haematocrit, haemoglobin, plasma protein and blood cell values of infected and moribund fish were significantly decreased. Histopathological findings included the occurrence of inflammation, cells necrosis, infiltration of lymphocytes and the formation of granulomas in the infected organs.

  5. Streptococcus pyogenes translocates across an epithelial barrier.

    Science.gov (United States)

    Sumitomo, Tomoko

    2017-01-01

    Streptococcus pyogenes is a β-hemolytic organism responsible for a wide variety of human diseases that commonly occur as self-limiting purulent diseases of the pharynx and skin. Although the occurrence of invasive infections by S. pyogenes is rare, mortality rates remain high even with progressive medical therapy. As a prerequisite for causing the severe invasive disease, S. pyogenes must invade underlying sterile tissues by translocating across the epithelial barrier. In this study, streptolysin S and SpeB were identified as the novel factors that facilitate bacterial translocation via degradation of intercellular junctions. Furthermore, we found that S. pyogenes exploits host plasminogen for acceleration of bacterial invasion into deeper tissues via tricellular tight junctions. Here, I would like to show our study on bacterial translocation across the epithelial barrier through paracellular route.

  6. Interaction between human polymorphonuclear leukocytes and Streptococcus milleri group bacteria.

    Science.gov (United States)

    Wanahita, Anna; Goldsmith, Elizabeth A; Musher, Daniel M; Clarridge, Jill E; Rubio, Jose; Krishnan, Bhuvaneswari; Trial, JoAnn

    2002-01-01

    Because Streptococcus milleri group (SMG) bacteria--Streptococcus constellatus, Streptococcus intermedius, and Streptococcus anginosus--exhibit a striking propensity to cause abscesses, the interaction of these organisms with human polymorphonuclear leukocytes (PMNL) was examined. After incubation in pooled normal human serum, SMG stimulated less chemotaxis than did Staphylococcus aureus, in contrast to viridans streptococci, which caused greater chemotaxis than did S. aureus. PMNL ingested greater numbers of SMG and viridans streptococci than S. aureus but killed these organisms more slowly and less completely. Relative resistance to killing by PMNL is expected in organisms that cause abscesses, and inhibition of chemotaxis may contribute to pathogenicity, because delayed arrival of PMNL gives a head start to proliferating bacteria. This study helps explain the capacity of SMG to cause abscesses. It is unclear, however, why viridans streptococci, bacteria that rarely produce abscesses, share some of these same properties.

  7. Antibiotic susceptibilities of genetically characterized Streptococcus milleri group strains.

    Science.gov (United States)

    Tracy, M; Wanahita, A; Shuhatovich, Y; Goldsmith, E A; Clarridge, J E; Musher, D M

    2001-05-01

    Previous studies of the antibiotic susceptibility of Streptococcus milleri group organisms have distinguished among species by using phenotypic techniques. Using 44 isolates that were speciated by 16S rRNA gene sequencing, we studied the MICs and minimum bactericidal concentrations of penicillin, ampicillin, ceftriaxone, and clindamycin for Streptococcus intermedius, Streptococcus constellatus, and Streptococcus anginosus. None of the organisms was resistant to beta-lactam antibiotics, although a few isolates were intermediately resistant; one strain of S. anginosus was tolerant to ampicillin, and another was tolerant to ceftriaxone. Six isolates were resistant to clindamycin, with representation from each of the three species. Relatively small differences in antibiotic susceptibilities among species of the S. milleri group show that speciation is unlikely to be important in selecting an antibiotic to treat infection caused by one of these isolates.

  8. Diversity of human small intestinal Streptococcus and Veillonella populations

    NARCIS (Netherlands)

    Bogert, B. van den; Erkus, O.; Boekhorst, J.; Goffau, M. de; Smid, E.J.; Zoetendal, E.G.; Kleerebezem, M.

    2013-01-01

    Molecular and cultivation approaches were employed to study the phylogenetic richness and temporal dynamics of Streptococcus and Veillonella populations in the small intestine. Microbial profiling of human small intestinal samples collected from four ileostomy subjects at four time points displayed

  9. Anti-Bacterial Activity of Phenolic Compounds against Streptococcus pyogenes

    DEFF Research Database (Denmark)

    Macé, Sabrina; Hansen, Lisbeth Truelstrup; P. Vasantha Rupasinghe, H.

    2017-01-01

    Background: Worldwide, Streptococcus pyogenes is the leading cause of bacterial pharyngitis. To reduce the use of antibiotics, antimicrobial phytochemical-containing remedies, which have long been in use in traditional medicine, may provide new approaches for management of streptococcal pharyngitis...

  10. Diversity of human small intestinal Streptococcus and Veillonella populations

    NARCIS (Netherlands)

    van den Bogert, Bartholomeus; Erkus, Oylum; Boekhorst, Jos; de Goffau, Marcus; Smid, Eddy J.; Zoetendal, Erwin G.; Kleerebezem, Michiel

    Molecular and cultivation approaches were employed to study the phylogenetic richness and temporal dynamics of Streptococcus and Veillonella populations in the small intestine. Microbial profiling of human small intestinal samples collected from four ileostomy subjects at four time points displayed

  11. Quantification of bovine oxylipids during intramammary Streptococcus uberis infection

    Science.gov (United States)

    Streptococcus uberis mastitis results in severe mammary tissue damage in dairy cows due to uncontrolled inflammation. Oxylipids are potent lipid mediators that orchestrate pathogen-induced inflammatory responses, however, changes in oxylipid biosynthesis during S. uberis mastitis are unknown. Thus, ...

  12. Evolution of Streptococcus pneumoniae and its close commensal relatives

    DEFF Research Database (Denmark)

    Kilian, Mogens; Poulsen, Knud; Blomqvist, Trinelise

    2008-01-01

    Streptococcus pneumoniae is a member of the Mitis group of streptococci which, according to 16S rRNA-sequence based phylogenetic reconstruction, includes 12 species. While other species of this group are considered prototypes of commensal bacteria, S. pneumoniae is among the most frequent microbial...... killers worldwide. Population genetic analysis of 118 strains, supported by demonstration of a distinct cell wall carbohydrate structure and competence pheromone sequence signature, shows that S. pneumoniae is one of several hundred evolutionary lineages forming a cluster separate from Streptococcus...... oralis and Streptococcus infantis. The remaining lineages of this distinct cluster are commensals previously collectively referred to as Streptococcus mitis and each represent separate species by traditional taxonomic standard. Virulence genes including the operon for capsule polysaccharide synthesis...

  13. The changing epidemiology of group B streptococcus bloodstream infection

    DEFF Research Database (Denmark)

    Ballard, Mark S; Schønheyder, Henrik C; Knudsen, Jenny Dahl

    2016-01-01

    Background Population-based studies conducted in single regions or countries have identified significant changes in the epidemiology of invasive group B streptococcus (GBS) infection. However, no studies have concurrently compared the epidemiology of GBS infections among multiple different regions...

  14. Carbohydrate-dependent gene regulation in Streptococcus pneumoniae

    NARCIS (Netherlands)

    Afzal, Muhammad

    2015-01-01

    Streptococcus pneumoniae, een Gram-positieve ziekteverwekker voor de mens, kan infecties als longontsteking, meningitis, middenoorontsteking en sepsis veroorzaken en veroorzaakt elk jaar miljoenen sterfgevallen, met name van kinderen en ouderen. Het gedrag van S. pneumoniae kan snel veranderen met

  15. Streptococcus pneumoniae in saliva of Dutch primary school children

    NARCIS (Netherlands)

    Wyllie, Anne L.; Chu, Mei Ling J. N.; Schellens, Mariëlle H. B.; van Engelsdorp Gastelaars, Jody; Jansen, Marc D.; van der Ende, Arie; Bogaert, Debby; Sanders, Elisabeth A. M.; Trzciński, Krzysztof

    2014-01-01

    While nasopharyngeal sampling is the gold standard for the detection of Streptococcus pneumoniae carriage, historically seen, saliva sampling also seems highly sensitive for pneumococcal detection. We investigated S. pneumoniae carriage in saliva from fifty schoolchildren by conventional and

  16. A model of efficiency: stress tolerance by Streptococcus mutans

    National Research Council Canada - National Science Library

    Lemos, Jose A; Burne, Robert A

    2008-01-01

    ... of Dentistry, Gainesville, FL 32610, USA Correspondence José A. Lemos Jose_Lemos{at}urmc.rochester.edu The complete genome sequence of Streptococcus mutans , a bacterial pathogen commonly associated with human dental caries, was published in 2002...

  17. Severe Streptococcus pyogenes infections, United Kingdom, 2003-2004

    National Research Council Canada - National Science Library

    Lamagni, Theresa L; Neal, Shona; Keshishian, Catherine; Alhaddad, Neelam; George, Robert; Duckworth, Georgia; Vuopio-Varkila, Jaana; Efstratiou, Androulla

    2008-01-01

    As part of a Europe-wide initiative to explore current epidemiologic patterns of severe disease caused by Streptococcus pyogenes, the United Kingdom undertook enhanced population-based surveillance during 2003-2004...

  18. The post-vaccine microevolution of invasive Streptococcus pneumoniae

    NARCIS (Netherlands)

    Cremers, A.J.H.; Mobegi, F.M.; Jonge, M.I. de; Hijum, S.A.F.T. van; Meis, J.F.; Hermans, P.W.M.; Ferwerda, G.; Bentley, S.D.; Zomer, A.L.

    2015-01-01

    The 7-valent pneumococcal conjugated vaccine (PCV7) has affected the genetic population of Streptococcus pneumoniae in pediatric carriage. Little is known however about pneumococcal population genomics in adult invasive pneumococcal disease (IPD) under vaccine pressure. We sequenced and serotyped

  19. Exogenous group G Streptococcus endophthalmitis following intravitreal ranibizumab injection

    Directory of Open Access Journals (Sweden)

    Kugu S

    2012-08-01

    Full Text Available Suleyman Kugu,1 Mehmet Sahin Sevim,2 Nilufer Zorlutuna Kaymak,1 Gurkan Erdogan,3 Baran Kandemir,1 Omer Kamil Dogan41Lutfi Kirdar Kartal Training and Research Hospital, Eye Clinic, Istanbul, 2Haydarpasa Numune Training and Research Hospital, Eye Clinic, Istanbul, 3Umraniye Training and Research Hospital, Eye Clinic, Istanbul, 4World Eye Hospital, Eye Clinic, Istanbul, TurkeyAbstract: We report a case of group G Streptococcus endophthalmitis following an intravitreal ranibizumab injection for a choroidal neovascular membrane. Pars plana vitrectomy was applied for endophthalmitis and group G Streptococcus cultures were isolated in the vitreous samples taken from the patient. Twenty-four hours following pars plana vitrectomy the patient underwent myocardial infarction and cardiac arrest. To our knowledge this is the first reported case of group G Streptococcus endophthalmitis following an intravitreal injection.Keywords: group G Streptococcus, endophthalmitis, intravitreal injection

  20. Mechanisms of genome evolution of Streptococcus.

    Science.gov (United States)

    Andam, Cheryl P; Hanage, William P

    2015-07-01

    The genus Streptococcus contains 104 recognized species, many of which are associated with human or animal hosts. A globally prevalent human pathogen in this group is Streptococcus pneumoniae (the pneumococcus). While being a common resident of the upper respiratory tract, it is also a major cause of otitis media, pneumonia, bacteremia and meningitis, accounting for a high burden of morbidity and mortality worldwide. Recent findings demonstrate the importance of recombination and selection in driving the population dynamics and evolution of different pneumococcal lineages, allowing them to successfully evade the impacts of selective pressures such as vaccination and antibiotic treatment. We highlight the ability of pneumococci to respond to these pressures through processes including serotype replacement, capsular switching and horizontal gene transfer (HGT) of antibiotic resistance genes. The challenge in controlling this pathogen also lies in the exceptional genetic and phenotypic variation among different pneumococcal lineages, particularly in terms of their pathogenicity and resistance to current therapeutic strategies. The widespread use of pneumococcal conjugate vaccines, which target only a small subset of the more than 90 pneumococcal serotypes, provides us with a unique opportunity to elucidate how the processes of selection and recombination interact to generate a remarkable level of plasticity and heterogeneity in the pneumococcal genome. These processes also play an important role in the emergence and spread of multi-resistant strains, which continues to pose a challenge in disease control and/or eradication. The application of population of genomic approaches at different spatial and temporal scales will help improve strategies to control this global pathogen, and potentially other pathogenic streptococci. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  1. Evaluation and directed evolution for thermostability improvement of a GH 13 thermostable α-glucosidase from Thermus thermophilus TC11.

    Science.gov (United States)

    Zhou, Cheng; Xue, Yanfen; Ma, Yanhe

    2015-10-21

    Thermal stable α-glucosidases with transglycosylation activity could be applied to the industrial production of oligosaccharides as well as conjugation of sugars to biologically useful materials. Therefore, α-glucosidases isolated from thermophiles have gained attention over the past decade. In this study, the characterization of a highly thermostable α-glucosidase and its thermostability improved mutant from newly isolated strain Thermus thermophilus TC11 were investigated. The recombinant α-glucosidase (TtAG) from Thermus thermophilus TC11 was expressed in Escherichia coli BL21 (DE3) and purified. The purified enzyme had a molecular mass of 184 kDa and consisted of 59-kDa subunits; it showed hydrolytic activity for pNP-α-D-glucopyranoside (pNPG), sucrose, trehalose, panose, and isomaltooligosaccharides and very low activity for maltose. The highest specific activity of 288.96 U/mg was observed for pNPG at 90 °C and pH 5.0; Pb(2+) provided a 20 % activity increase. TtAG was stable at 70 °C for more than 7 h and had a half-life of 195 min at 80 °C and 130 min at 90 °C. Transglycosylation activity was also observed with sucrose and trehalose as substrates. TtAG showed differences on substrate specificity, transglycosylation, multimerization, effects of metal ions and optimal pH from other reported Thermus α-glucosidases. One single-substitution TtAG mutant Q10Y with improved thermostability was also obtained from random mutagenesis library. The site-saturation mutagenesis and structural modelling analysis indicated that Q10Y substitution stabilized TtAG structure via additional hydrogen bonding and hydrophobic interactions. Our findings indicate that TtAG is a highly thermostable and more acidic α-glucosidase distinct from other reported Thermus α-glucosidases. And this work also provides new insights into the catalytic and thermal tolerance mechanisms of α-glucosidases, which may guide molecular engineering of α-glucosidase and other

  2. Presumptive identification of "Streptococcus milleri" in 5 h.

    Science.gov (United States)

    Ruoff, K L; Ferraro, M J

    1986-01-01

    Rapid miniaturized tests for acetoin production, arginine hydrolysis, and sorbitol fermentation were used for presumptive identification of non-beta-hemolytic "Streptococcus milleri" isolates in 5 h. All 77 "S. milleri" strains tested were Voges-Proskauer positive, arginine hydrolysis positive, and sorbitol fermentation negative. On the basis of these reactions, "S. milleri" was differentiated from isolates of other viridans group streptococcal species and from Streptococcus bovis. PMID:3760146

  3. Cariogenicity features of Streptococcus mutans in presence of rubusoside

    OpenAIRE

    Chu, Jinpu; Zhang, Tieting; He, Kexin

    2016-01-01

    Background One promising way of reducing caries is by using sucrose substitutes in food. rubusoside is a prototype sweet substance isolated from the leaves of the plant Rubrus suavissimus S. Lee. (Rosaceae), and is rated sweeter than sucrose. The purpose of this study was to investigate the effects of rubusoside on Streptococcus mutans growth, acidogenicity, and adherence to glass in vitro. Methods The effects of rubusoside on the growth and glass surface adhering of Streptococcus mutans were...

  4. Serotype-specific mortality from invasive Streptococcus pneumoniae disease revisited

    DEFF Research Database (Denmark)

    Martens, Pernille; Worm, Signe Westring; Lundgren, Bettina

    2004-01-01

    Serotype-specific mortality from invasive Streptococcus pneumoniae disease revisited.Martens P, Worm SW, Lundgren B, Konradsen HB, Benfield T. Department of Infectious Diseases 144, Hvidovre University Hospital, DK-2650 Hvidovre, Denmark. pernillemartens@yahoo.com BACKGROUND: Invasive infection...... with Streptococcus pneumoniae (pneumococci) causes significant morbidity and mortality. Case series and experimental data have shown that the capsular serotype is involved in the pathogenesis and a determinant of disease outcome. METHODS: Retrospective review of 464 cases of invasive disease among adults diagnosed...

  5. Balanitis caused by Streptococcus pyogenes: a report of two cases.

    Science.gov (United States)

    Sakuma, S; Komiya, H

    2005-09-01

    Streptococcus pyogenes (the Lancefield group A streptococcus) is a cause of pharyngitis and impetigo. However, it has rarely been implicated as a sexually transmitted pathogen. We herein report two cases of severe balanitis due to S. pyogenes in sexually active men. It is postulated that penile cellulitis developed following the invasion of S. pyogenes through a traumatic abrasion acquired during fellatio performed by commercial sex workers. Both patients were treated successfully with oral administration of penicillin.

  6. Protease production by Streptococcus sanguis associated with subacute bacterial endocarditis.

    OpenAIRE

    Straus, D. C.

    1982-01-01

    A viridans streptococcus (Streptococcus sanguis biotype II) isolated from the blood of a patient with subacute bacterial endocarditis was examined for protease production. In broth culture, extracellular proteolytic enzymes were not produced by this organism until after the early exponential phase of growth, with maximal protease production occurring during the stationary phase. Four distinct proteases were isolated and purified from the supernatant fluids of stationary-phase cultures, employ...

  7. Chemical and botanical characterization of Chilean propolis and biological activity on cariogenic bacteria Streptococcus mutans and Streptococcus sobrinus

    OpenAIRE

    Leticia Barrientos; Herrera, Christian L.; Gloria Montenegro; Ximena Ortega; Jorge Veloz; Marysol Alvear; Alejandro Cuevas; Nicolás Saavedra; Salazar, Luis A.

    2013-01-01

    Propolis is a non-toxic natural substance with multiple pharmacological properties including anti-cancer, antioxidant, fungicidal, antibacterial, antiviral, and anti-inflammatory among others. The aim of this study was to determine the chemical and botanical characterization of Chilean propolis samples and to evaluate their biological activity against the cariogenic bacteria Streptococcus mutans and Streptococcus sobrinus. Twenty propolis samples were obtained from beekeeping producers from t...

  8. Influence of time, toothpaste and saliva in the retention of Streptococcus mutans and Streptococcus sanguinis on different toothbrushes

    OpenAIRE

    SCHMIDT, Julia Caroline; BUX, Miriam; FILIPUZZI-JENNY, Elisabeth; KULIK, Eva Maria; WALTIMO, Tuomas; WEIGER, Roland; WALTER, Clemens

    2014-01-01

    Objectives: The intraoral transmission of cariogenic and periodontopathogenic species seems to be facilitated by contaminated toothbrushes and other oral hygiene devices. The aim of this investigation was to analyze the in vitro retention and survival rate of Streptococcus mutans and Streptococcus sanguinis on different toothbrushes. The impacts of human saliva and antimicrobial toothpaste on these parameters were further evaluated. Material and Methods: Part I: Four toothbrushes (Colgate 3...

  9. Salivary density of Streptococcus mutans and Streptococcus sobrinus and dental caries in children and adolescents with Down syndrome

    OpenAIRE

    SCALIONI, Fl?via; Camila CARRADA; Machado,Fernanda; Karina, DEVITO; Ribeiro, Luiz Cl?udio; CESAR, Dion?ia; RIBEIRO, Rosangela

    2017-01-01

    Abstract Streptococcus mutans and Streptococcus sobrinus are strongly associated with dental caries. However, the relationship between oral streptococci and dental caries in children with Down syndrome is not well characterized. Objective To assess and compare dental caries experience and salivary S. mutans, S. sobrinus, and streptococci counts between groups of Down syndrome and non-Down syndrome children and adolescents. Material and Methods This study included a sample of 30 Down syndrome ...

  10. Development of Primer Sets for Loop-Mediated Isothermal Amplification that Enables Rapid and Specific Detection of Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae

    Directory of Open Access Journals (Sweden)

    Deguo Wang

    2015-05-01

    Full Text Available Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae are the three main pathogens causing bovine mastitis, with great losses to the dairy industry. Rapid and specific loop-mediated isothermal amplification methods (LAMP for identification and differentiation of these three pathogens are not available. With the 16S rRNA gene and 16S-23S rRNA intergenic spacers as targets, four sets of LAMP primers were designed for identification and differentiation of S. dysgalactiae, S. uberis and S. agalactiae. The detection limit of all four LAMP primer sets were 0.1 pg DNA template per reaction, the LAMP method with 16S rRNA gene and 16S-23S rRNA intergenic spacers as the targets can differentiate the three pathogens, which is potentially useful in epidemiological studies.

  11. Development of Primer Sets for Loop-Mediated Isothermal Amplification that Enables Rapid and Specific Detection of Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae.

    Science.gov (United States)

    Wang, Deguo; Liu, Yanhong

    2015-05-26

    Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae are the three main pathogens causing bovine mastitis, with great losses to the dairy industry. Rapid and specific loop-mediated isothermal amplification methods (LAMP) for identification and differentiation of these three pathogens are not available. With the 16S rRNA gene and 16S-23S rRNA intergenic spacers as targets, four sets of LAMP primers were designed for identification and differentiation of S. dysgalactiae, S. uberis and S. agalactiae. The detection limit of all four LAMP primer sets were 0.1 pg DNA template per reaction, the LAMP method with 16S rRNA gene and 16S-23S rRNA intergenic spacers as the targets can differentiate the three pathogens, which is potentially useful in epidemiological studies.

  12. Exploring the proton pump and exit pathway for pumped protons in cytochrome ba3 from Thermus thermophilus

    Science.gov (United States)

    Chang, Hsin-Yang; Choi, Sylvia K.; Vakkasoglu, Ahmet Selim; Chen, Ying; Hemp, James; Fee, James A.; Gennis, Robert B.

    2012-01-01

    The heme-copper oxygen reductases are redox-driven proton pumps. In the current work, the effects of mutations in a proposed exit pathway for pumped protons are examined in the ba3-type oxygen reductase from Thermus thermophilus, leading from the propionates of heme a3 to the interface between subunits I and II. Recent studies have proposed important roles for His376 and Asp372, both of which are hydrogen-bonded to propionate-A of heme a3, and for Glu126II (subunit II), which is hydrogen-bonded to His376. Based on the current results, His376, Glu126II, and Asp372 are not essential for either oxidase activity or proton pumping. In addition, Tyr133, which is hydrogen-bonded to propionate-D of heme a3, was also shown not to be essential for function. However, two mutations of the residues hydrogen-bonded to propionate-A, Asp372Ile and His376Asn, retain high electron transfer activity and normal spectral features but, in different preparations, either do not pump protons or exhibit substantially diminished proton pumping. It is concluded that either propionate-A of heme a3 or possibly the cluster of groups centered about the conserved water molecule that hydrogen-bonds to both propionates-A and -D of heme a3 is a good candidate to be the proton loading site. PMID:22431640

  13. Crystallization and preliminary X-ray analysis of peptidyl-tRNA hydrolase from Thermus thermophilus HB8.

    Science.gov (United States)

    Matsumoto, Ami; Shimizu, Yoshihiro; Takemoto, Chie; Ueda, Takuya; Uchiumi, Toshio; Ito, Kosuke

    2013-03-01

    Peptidyl-tRNA is produced from the ribosome as a result of aborted translation. Peptidyl-tRNA hydrolase cleaves the ester bond between the peptide and the tRNA of peptidyl-tRNA molecules, to recycle tRNA for further rounds of protein synthesis. In this study, peptidyl-tRNA hydrolase from Thermus thermophilus HB8 (TthPth) was crystallized using 2-methyl-2,4-pentanediol as a precipitant. The crystals belonged to the orthorhombic space group P2₁2₁2₁, with unit-cell parameters a=47.45, b=53.92, c=58.67 Å, and diffracted X-rays to atomic resolution (beyond 1.0 Å resolution). The asymmetric unit is expected to contain one TthPth molecule, with a solvent content of 27.13% (VM=1.69 Å3 Da(-1)). The structure is being solved by molecular replacement.

  14. Crystallization and preliminary X-ray diffraction analysis of recombinant phosphoribosylpyrophosphate synthetase from the Thermophilic thermus thermophilus strain HB27

    Science.gov (United States)

    Abramchik, Yu. A.; Timofeev, V. I.; Muravieva, T. I.; Sinitsyna, E. V.; Esipov, R. S.; Kuranova, I. P.

    2017-01-01

    Phosphoribosylpyrophosphate synthetases (PRPP synthetases) are among the key enzymes essential for vital functions of organisms and are involved in the biosynthesis of purine and pyrimidine nucleotides, coenzymes, and the amino acids histidine and tryptophan. These enzymes are used in biotechnology for the combined chemoenzymatic synthesis of natural nucleotide analogs. Recombinant phosphoribosylpyrophosphate synthetase I from the thermophilic strain HB27 of the bacterium Thermus thermophilus ( T. th HB27) has high thermal stability and shows maximum activity at 75°C, due to which this enzyme holds promise for biotechnological applications. In order to grow crystals and study them by X-ray crystallography, an enzyme sample, which was produced using a highly efficient producer strain, was purified by affinity and gel-filtration chromatography. The screening of crystallization conditions was performed by the vapor-diffusion technique. The crystals of the enzyme suitable for X-ray diffraction were grown by the counter-diffusion method through a gel layer. These crystals were used to collect the X-ray diffraction data set at the SPring-8 synchrotron radiation facility (Japan) to 3-Å resolution. The crystals belong to sp. gr. P21 and have the following unitcell parameters: a = 107.7 Å, b = 112.6 Å, c = 110.2 Å, α = γ = 90°, β = 116.6°. The X-ray diffraction data set is suitable for determining the three-dimensional structure of the enzyme at 3.0-Å resolution.

  15. Inactivation and unfolding of protein tyrosine phosphatase from Thermus thermophilus HB27 during urea and guanidine hydrochloride denaturation.

    Directory of Open Access Journals (Sweden)

    Yejing Wang

    Full Text Available The effects of urea and guanidine hydrochloride (GdnHCl on the activity, conformation and unfolding process of protein tyrosine phosphatase (PTPase, a thermostable low molecular weight protein from Thermus thermophilus HB27, have been studied. Enzymatic activity assays showed both urea and GdnHCl resulted in the inactivation of PTPase in a concentration and time-dependent manner. Inactivation kinetics analysis suggested that the inactivation of PTPase induced by urea and GdnHCl were both monophasic and reversible processes, and the effects of urea and GdnHCl on PTPase were similar to that of mixed-type reversible inhibitors. Far-ultraviolet (UV circular dichroism (CD, Tryptophan and 1-anilinonaphthalene -8-sulfonic acid (ANS fluorescence spectral analyses indicated the existence of a partially active and an inactive molten globule-like intermediate during the unfolding processes induced by urea and GdnHCl, respectively. Based on the sequence alignment and the homolog Tt1001 protein structure, we discussed the possible conformational transitions of PTPase induced by urea and GdnHCl and compared the conformations of these unfolding intermediates with the transient states in bovine PTPase and its complex structures in detail. Our results may be able to provide some valuable clues to reveal the relationship between the structure and enzymatic activity, and the unfolding pathway and mechanism of PTPase.

  16. Crystallization and preliminary X-ray diffraction analysis of recombinant phosphoribosylpyrophosphate synthetase from the Thermophilic thermus thermophilus strain HB27

    Energy Technology Data Exchange (ETDEWEB)

    Abramchik, Yu. A. [Russian Academy of Sciences, Shemyakin–Ovchinnikov Institute of Bioorganic Chemistry (Russian Federation); Timofeev, V. I., E-mail: tostars@mail.ru [Russian Academy of Sciences, Shubnikov Institute of Crystallography of Federal Scientific Research Centre “Crystallography and Photonics” (Russian Federation); Muravieva, T. I.; Sinitsyna, E. V.; Esipov, R. S., E-mail: esipov@mx.ibch.ru [Russian Academy of Sciences, Shemyakin–Ovchinnikov Institute of Bioorganic Chemistry (Russian Federation); Kuranova, I. P., E-mail: inna@ns.crys.ras.ru [Russian Academy of Sciences, Shubnikov Institute of Crystallography of Federal Scientific Research Centre “Crystallography and Photonics” (Russian Federation)

    2017-01-15

    Phosphoribosylpyrophosphate synthetases (PRPP synthetases) are among the key enzymes essential for vital functions of organisms and are involved in the biosynthesis of purine and pyrimidine nucleotides, coenzymes, and the amino acids histidine and tryptophan. These enzymes are used in biotechnology for the combined chemoenzymatic synthesis of natural nucleotide analogs. Recombinant phosphoribosylpyrophosphate synthetase I from the thermophilic strain HB27 of the bacterium Thermus thermophilus (T. th HB27) has high thermal stability and shows maximum activity at 75°Ð¡, due to which this enzyme holds promise for biotechnological applications. In order to grow crystals and study them by X-ray crystallography, an enzyme sample, which was produced using a highly efficient producer strain, was purified by affinity and gel-filtration chromatography. The screening of crystallization conditions was performed by the vapor-diffusion technique. The crystals of the enzyme suitable for X-ray diffraction were grown by the counter-diffusion method through a gel layer. These crystals were used to collect the X-ray diffraction data set at the SPring-8 synchrotron radiation facility (Japan) to 3-Å resolution. The crystals belong to sp. gr. P2{sub 1} and have the following unitcell parameters: a = 107.7 Å, b = 112.6 Å, c = 110.2 Å, α = γ = 90°, β = 116.6°. The X-ray diffraction data set is suitable for determining the three-dimensional structure of the enzyme at 3.0-Å resolution.

  17. Exploring the proton pump and exit pathway for pumped protons in cytochrome ba3 from Thermus thermophilus.

    Science.gov (United States)

    Chang, Hsin-Yang; Choi, Sylvia K; Vakkasoglu, Ahmet Selim; Chen, Ying; Hemp, James; Fee, James A; Gennis, Robert B

    2012-04-03

    The heme-copper oxygen reductases are redox-driven proton pumps. In the current work, the effects of mutations in a proposed exit pathway for pumped protons are examined in the ba(3)-type oxygen reductase from Thermus thermophilus, leading from the propionates of heme a(3) to the interface between subunits I and II. Recent studies have proposed important roles for His376 and Asp372, both of which are hydrogen-bonded to propionate-A of heme a(3), and for Glu126(II) (subunit II), which is hydrogen-bonded to His376. Based on the current results, His376, Glu126(II), and Asp372 are not essential for either oxidase activity or proton pumping. In addition, Tyr133, which is hydrogen-bonded to propionate-D of heme a(3), was also shown not to be essential for function. However, two mutations of the residues hydrogen-bonded to propionate-A, Asp372Ile and His376Asn, retain high electron transfer activity and normal spectral features but, in different preparations, either do not pump protons or exhibit substantially diminished proton pumping. It is concluded that either propionate-A of heme a(3) or possibly the cluster of groups centered about the conserved water molecule that hydrogen-bonds to both propionates-A and -D of heme a(3) is a good candidate to be the proton loading site.

  18. Pb2+ Effects on Growth, Lipids, and Protein and DNA Profiles of the Thermophilic Bacterium Thermus Thermophilus

    Directory of Open Access Journals (Sweden)

    Barbara Nicolaus

    2016-12-01

    Full Text Available Extremophiles are organisms able to thrive in extreme environmental conditions and some of them show the ability to survive high doses of heavy metals thanks to defensive mechanisms provided by primary and secondary metabolic products, i.e., extremolytes, lipids, and extremozymes. This is why there is a growing scientific and industrial interest in the use of thermophilic bacteria in a host of tasks, from the environmental detoxification of heavy metal to industrial activities, such as bio-machining and bio-metallurgy. In this work Thermus thermophilus was challenged against increasing Pb2+ concentrations spanning from 0 to 300 ppm in order to ascertain the sensitiveness of this bacteria to the Pb environmental pollution and to give an insight on its heavy metal resistance mechanisms. Analysis of growth parameters, enzyme activities, protein profiles, and lipid membrane modifications were carried out. In addition, genotyping analysis of bacteria grown in the presence of Pb2+, using random amplified polymorphic DNA-PCR and DNA melting evaluation, were also performed. A better knowledge of the response of thermophilic bacteria to the different pollutants, as heavy metals, is necessary for optimizing their use in remediation or decontamination processes.

  19. Characterization of Streptococcus sanguis molecular receptors for Streptococcus mutans binding molecules

    Directory of Open Access Journals (Sweden)

    Deby Kania Tri Putri

    2016-12-01

    Full Text Available Background: Dental caries is a major problem in oral cavity. If dental caries causes cavity, the structure of dental hard tissue will not be reversible because of damage in the structure of the hard tissue. The early pathogenesis mechanism of dental caries is an adhesion interaction between cariogenic Streptococcus mutans microorganisms and tooth surface pellicles. The attachment involves a specific molecular component interaction between the bacterial complement molecules and the surface of the host. Streptococcus sanguis as a dominant ecology at the beginning of bacterial plaque aggregation will colonize the tooth surface earlier than S. mutans. The surface of bacterial cells can express some adesin. The bacteria also can express receptors for adhesins of other bacteria. Specific receptors for adhesions of S. Mutans bacteria are not only found in the pellicles, but also present in pioneer bacteria, such as S. sanguis. Adhesion between those bacteria is called as coagregation. Purpose: This study aimed to analyze the characterization of Streptococcus sanguis molecular receptors for Streptococcus mutans binding molecules. Method: This study used a sonication method for protein isolation of S. mutans and S. sanguis bacterial biofilms, as well as electrophoresis method using 12 % SDS-PAGE gel and Western Blot analysis. Result: Results of the protein profile analysis of S. mutans biofilms using 12% SDS-PAGE showed that there were 17 bands, each of which molecular weights was 212, 140, 81, 65, 61, 48, 45, 44, 40, 39, 33 , 25, 23, 19, 17, 12, and 11 kDa. On the other hand, results of the protein profile analysis of S. sanguis biofilms using 12% SDS-PAGE showed that there were 15 bands, each of which molecular weight was 130, 85, 65, 61, 48, 46, 40, 37, 29, 25, 23, 21, 17, 15, and 12 kDa. And, results of the analysis of S. sanguis receptor molecules using Western blot showed that there were three bands, each of which molecular weight was 130, 85, and

  20. Studies concerning the glucosyltransferase of Streptococcus sanguis.

    Science.gov (United States)

    Vacca Smith, A M; Ng-Evans, L; Wunder, D; Bowen, W H

    2000-01-01

    We have shown in previous studies that the glucosyltransferase (Gtf) enzymes of Streptococcus mutans have distinct properties when adsorbed to a surface. In the present study, we compared the activity of Gtf from Streptococcus sanguis, designated GtfSs, in solution and on the surface of saliva-coated hydroxyapatite (sHA) beads, and determined the ability of its product glucan to support the adherence of oral microorganisms. Gtf from S. sanguis 804 NCTC 10904 was purified from culture supernatant fluids by means of hydroxyapatite chromatography. Enzyme and the substrate were prepared in buffers at pH values from 3.5 to 7.5. Maximum activity of GtfSs occurred between pH 5.5 and pH 6.5, whether in solution or adsorbed onto a surface. The solubilized and insolubilized enzymes showed highest activity at 40 degrees C; activity was reduced by 50(+/-2)% at 20 and 30 degrees C. The enzyme did not form glucans in either phase at 10 or 60 degrees C. The K(m), determined from Lineweaver-Burk plots, for the enzyme in solution was 4.3(+/-0.4) mmol/l sucrose, and the K(m) for the enzyme on sHA beads was 5.0(+/-1.0) mmol/l sucrose. The ability of the GtfSs glucan synthesized on the surface of sHA beads to support the adherence of oral bacteria was investigated. (3)H-thymidine-labeled bacteria (S. mutans GS-5, S. sobrinus 6715, S. sobrinus 6716, S. sanguis 10904, Actinomyces viscosus OMZ105E, A. viscosus 2085, and A. viscosus 2086) were incubated with sHA beads coated with GtfSs glucan. S. mutans GS-5 displayed the highest level of binding numerically. These results show that the GtfSs of S. sanguis is active on sHA beads, that the pH optimum for activity on a surface differs slightly from that in solution, and that its product glucan can support the adherence of oral microorganisms.

  1. Características laboratoriais das ceratites e conjuntivites causadas por Streptococcus sp Laboratorial findings of Streptococcus keratitis and conjunctivitis

    Directory of Open Access Journals (Sweden)

    Helena Parente Solari

    2004-10-01

    Full Text Available OBJETIVOS: Analisar os resultados laboratoriais de conjuntivites e ceratites com cultura positiva para Streptococcus sp, avaliando a incidência das diferentes espécies e os dados dos antibiogramas. MÉTODOS: Estudo retrospectivo de revisão de prontuários de pacientes encaminhados ao laboratório de Doenças Externas do Departamento de Oftalmologia da UNIFESP com resultado de cultivo bacteriano positivo de córnea ou conjuntiva e com identificação de alguma cepa do gênero Streptococcus sp, no período de janeiro de 1995 a dezembro de 2001. Analisou-se idade do paciente, espécie de Streptococcus e os testes de sensibilidade aos seguintes antibióticos: cefalotina, amicacina, gentamicina, tobramicina, ciprofloxacina, lomefloxacina, ofloxacina, norfloxacina e vancomicina. RESULTADOS: As espécies mais encontradas foram Streptococcus pneumoniae e Streptococcus viridans. Com relação aos antibióticos, a sensibilidade foi maior à cefalotina, às quinolonas e à vancomicina. CONCLUSÕES: Considerando-se os antibióticos tópicos comercialmente disponíveis, as quinolonas apresentam melhor espectro de ação quando comparadas aos aminoglicosídios.PURPOSE: To evaluate laboratorial findings of Streptococcus keratitis and conjunctivitis, analyzing the different species and the results of bacterial susceptibility to an antibiotics. METHODS: Retrospective study of the records from the External Disease Laboratory of the Ophthalmology Department of the Federal University of São Paulo, with conjunctival or corneal positive bacterial culture for Streptococcus sp, between January 1995 and December 2001. The collected data were age, Streptococcus species and the bacterial susceptibility to the following antibiotics: cephalotin, amikacin, gentamicin, tobramicin, ciprofloxacin, lomefloxacin, ofloxacin, norfloxacin and vancomicin. RESULTS: The most frequent species were Streptococcus pneumoniae and Streptococcus viridans. Regarding bacterial

  2. Capsular typing of Streptococcus agalactiae (Lancefield group B streptococci) from fish using multiplex PCR and serotyping

    Science.gov (United States)

    Streptococcus spp. including Streptococcus agalactiae (Lancefield group B streptococci) are considered emerging pathogens responsible for approximately $1 billion USD in annual losses to the global tilapia (Oreochromis sp.) aquaculture industry. This study evaluated a published multiplex PCR capsul...

  3. Streptococcus agalactiae clones infecting humans were selected and fixed through the extensive use of tetracycline

    National Research Council Canada - National Science Library

    Da Cunha, Violette; Davies, Mark R; Douarre, Pierre-Emmanuel; Rosinski-Chupin, Isabelle; Margarit, Immaculada; Spinali, Sebastien; Perkins, Tim; Lechat, Pierre; Dmytruk, Nicolas; Sauvage, Elisabeth; Ma, Laurence; Romi, Benedetta; Tichit, Magali; Lopez-Sanchez, Maria-José; Descorps-Declere, Stéphane; Souche, Erika; Buchrieser, Carmen; Trieu-Cuot, Patrick; Moszer, Ivan; Clermont, Dominique; Maione, Domenico; Bouchier, Christiane; McMillan, David J; Parkhill, Julian; Telford, John L; Dougan, Gordan; Walker, Mark J; Holden, Matthew T G; Poyart, Claire; Glaser, Philippe

    2014-01-01

    Streptococcus agalactiae (Group B Streptococcus, GBS) is a commensal of the digestive and genitourinary tracts of humans that emerged as the leading cause of bacterial neonatal infections in Europe and North America during the 1960s...

  4. Comparing the cariogenic species Streptococcus sobrinus and S. mutans on whole genome level

    NARCIS (Netherlands)

    Conrads, G.; de Soet, J.J.; Song, L.; Henne, K.; Sztajer, H.; Wagner-Döbler, I.; Zeng, A.P.

    2014-01-01

    Background: Two closely related species of mutans streptococci, namely Streptococcus mutans and Streptococcus sobrinus, are associated with dental caries in humans. Their acidogenic and aciduric capacity is directly associated with the cariogenic potential of these bacteria. To survive acidic and

  5. Molecular and mathematical epidemiology of Staphylococcus aureus and Streptococcus uberis mastitis in dairy herds

    NARCIS (Netherlands)

    Zadoks, Ruth Nicolet

    2002-01-01

    Mastitis is the most common and costly production disease affecting dairy cows. Staphylococcus aureus and Streptococcus uberis are two major mastitis-causing pathogens. Staphylococcus aureus is traditionally classified as contagious pathogen, while Streptococcus uberis is classified as environmental

  6. Quorum sensing in group A Streptococcus

    Science.gov (United States)

    Jimenez, Juan Cristobal; Federle, Michael J.

    2014-01-01

    Quorum sensing (QS) is a widespread phenomenon in the microbial world that has important implications in the coordination of population-wide responses in several bacterial pathogens. In Group A Streptococcus (GAS), many questions surrounding QS systems remain to be solved pertaining to their function and their contribution to the GAS lifestyle in the host. The QS systems of GAS described to date can be categorized into four groups: regulator gene of glucosyltransferase (Rgg), Sil, lantibiotic systems, and LuxS/AI-2. The Rgg family of proteins, a conserved group of transcription factors that modify their activity in response to signaling peptides, has been shown to regulate genes involved in virulence, biofilm formation and competence. The sil locus, whose expression is regulated by the activity of signaling peptides and a putative two-component system (TCS), has been implicated on regulating genes involved with invasive disease in GAS isolates. Lantibiotic regulatory systems are involved in the production of bacteriocins and their autoregulation, and some of these genes have been shown to target both bacterial organisms as well as processes of survival inside the infected host. Finally AI-2 (dihydroxy pentanedione, DPD), synthesized by the LuxS enzyme in several bacteria including GAS, has been proposed to be a universal bacterial communication molecule. In this review we discuss the mechanisms of these four systems, the putative functions of their targets, and pose critical questions for future studies. PMID:25309879

  7. Paleomicrobiological study in dental calculus: Streptococcus mutans.

    Science.gov (United States)

    Linossier, A; Gajardo, M; Olavarria, J

    1996-01-01

    Morphological types of bacterial remains preserved in ancient tartar of teeth from extinct human groups, which included some communities of coastal gatherers, fishermen, hunters, and farmers, and those practicing a mixed economy, were analyzed. Previous studies have shown the presence of bacteria in ancient tartar. The aim of this work was to determine whether Streptococcus mutans was present in ancient populations (500-12,000 years old). Teeth samples were from ancient skulls obtained from different anthropological collections: the north and south of Chile (before the Spanish conquest), Palencia, Spain, and an eastern Mediterranean region (Levant). Optical microscopy showed Gram positive and Gram negative bacteria. Scanning electron microscopy identified morphological types of bacteria. Transmission electron microscopy enabled categorization of bacterial structures. Fluorescence microscopy helped label and identify S. mutans, using polyclonal antibodies. Bacterial morphotypes were related to different subsistence patterns. Hunters, fishermen, and gatherers had a less diverse flora with bacillary and coccal morphotypes. Agricultural groups showed greater diversity with additional filamentous and spiral morphotypes. The best preserved ultrastructural feature was the cell wall. The existence and colonization capacity of the mutans-like streptococci preserved in tartar was established for the ancient populations studied, with the exception of Cerro Sotta (south of Chile). Hence, their occurrence could not be related to diet or subsistence pattern.

  8. Streptococcus pneumoniae colonization in remote African Pygmies.

    Science.gov (United States)

    Schaumburg, Frieder; Alabi, Abraham; von Eiff, Christof; Flamen, Arnaud; Traore, Hafsatou; Grobusch, Martin Peter; Peters, Georg; Kremsner, Peter Gottfried; van der Linden, Mark

    2013-02-01

    African Pygmies have many risk factors for invasive pneumococcal disease (IPD), such as low socioeconomic status and low quality of health care. We characterized Streptococcus pneumoniae from Gabonese Pygmies and analyzed risk factors for S. pneumoniae carriage to improve prophylaxis and therapy of IPD in this neglected, remotely living African community. Nasopharyngeal carriage of S. pneumoniae, susceptibility, serotypes and risk factors for IPD were assessed in 103 Pygmies in a cross-sectional study. The carriage rate was 37% (n = 38), with the highest proportion (79%, n = 11) in children between two and four years (n = 14). The predominant serotypes were 15A (24%, n = 9), 11A (16%, n = 6) and 6A (13%, n = 5). Non-susceptibility was detected against penicillin (Clinical and Laboratory Standards Institute; CLSI) meningitis breakpoints; (18%, n = 7), trimethoprim/sulfamethoxazole (61%, n = 23), tetracycline (55%, n = 21) and chloramphenicol (3%, n = 1). Among adult participants (n = 51), 69% (n = 35) regularly consumed alcohol and 75% (n = 38) reported to smoke cigarettes. The high proportion of nicotine and drug abuse might increase the risk of IPD. The unusual serotypes challenge a broad coverage by currently marketed vaccines; the broad antibiotic resistance limits the choice of therapy for S. pneumoniae infection.

  9. Generic determinants of Streptococcus colonization and infection.

    Science.gov (United States)

    Nobbs, Angela H; Jenkinson, Howard F; Everett, Dean B

    2015-07-01

    Bacteria within the genus Streptococcus have evolved to become exquisitely adapted to the colonization of humans and other animals. These bacteria predominantly live in harmony with their hosts, but all have capacity to cause disease should prevailing conditions allow. Streptococci express a myriad of colonization and virulence attributes that promote their survival at a variety of ecological sites. Many of these factors are surface-expressed adhesins that exhibit conservation at structural or functional levels across the genus. This reflects the importance of adherence interactions with a multitude of host substrata, such as epithelia or extracellular matrix components, to streptococcal survival. Other important factors are more restricted in their distribution, often conferring pathogenic capabilities associated with immune evasion or host tissue destruction. Evidence suggests that dissemination of these streptococcal attributes has frequently been driven by the movement of genetic material via lateral gene transfer, reflecting ecological pressures. Such recombination events have simultaneously facilitated extensive diversification, resulting in distinct tropisms at the species- or strain- level. These generic determinants offer significant potential as targets for combating streptococcal disease. However, this will depend upon better understanding of their mechanistic basis, and refined mapping of their distribution by epidemiological and metagenomic studies. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Efflux inhibitor suppresses Streptococcus mutans virulence properties.

    Science.gov (United States)

    Zeng, Huihui; Liu, Jia; Ling, Junqi

    2017-04-01

    It is well established that efflux pumps play important roles in bacterial pathogenicity and efflux inhibitors (EIs) have been proved to be effective in suppressing bacterial virulence properties. However, little is known regarding the EI of Streptococcus mutans, a well-known caries-inducing bacterium. In this study, we identified the EI of S. mutans through ethidium bromide efflux assay and investigated how EI affected S. mutans virulence regarding the cariogenicity and stress response. Results indicated that reserpine, the identified EI, suppressed acid tolerance, mutacin production and transformation efficiency of S. mutans, and modified biofilm architecture and extracellular polysaccharide distribution. Suppressed glycosyltransferase activity was also noted after reserpine exposure. The data from quantitative real-time-PCR demonstrated that reserpine significantly altered the expression profile of quorum-sensing and virulence-associated genes. These findings suggest that reserpine represents a promising adjunct anticariogenic agent in that it suppresses virulence properties of S. mutans. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. Phenotypic heterogeneity of Streptococcus mutans in dentin.

    Science.gov (United States)

    Rupf, S; Hannig, M; Breitung, K; Schellenberger, W; Eschrich, K; Remmerbach, T; Kneist, S

    2008-12-01

    Information concerning phenotypic heterogeneity of Streptococcus mutans in carious dentin is sparse. Matrix-assisted laser-desorption/ionization-time-of-flight mass-spectrometry (MALDI-TOF-MS) facilitates the phenotypic differentiation of bacteria to the subspecies level. To verify a supposed influence of restorative treatment on the phenotypic heterogeneity of S. mutans, we isolated and compared a total of 222 S. mutans strains from dentin samples of 21 human deciduous molars during caries excavation (T(1)) and 8 wks (T(2)) after removal of the temporary restoration. Phenotypic heterogeneity was determined by MALDI-TOF-MS and hierarchical clustering. Thirty-six distinct S. mutans phenotypes could be identified. Although indistinguishable phenotypes were found in the same teeth at T(1) and T(2), as well as in different teeth of individual participants, the phenotypic heterogeneity increased significantly, from 1.4 phenotypes per S. mutans-positive dentin sample at T(1) to 2.2 phenotypes at T(2). We attribute this to an adaptation of S. mutans to the modified environment under the restoration following caries excavation.

  12. Molecular typing of Chinese Streptococcus pyogenes isolates.

    Science.gov (United States)

    You, Yuanhai; Wang, Haibin; Bi, Zhenwang; Walker, Mark; Peng, Xianhui; Hu, Bin; Zhou, Haijian; Song, Yanyan; Tao, Xiaoxia; Kou, Zengqiang; Meng, Fanliang; Zhang, Menghan; Bi, Zhenqiang; Luo, Fengji; Zhang, Jianzhong

    2015-06-01

    Streptococcus pyogenes causes human infections ranging from mild pharyngitis and impetigo to serious diseases including necrotizing fasciitis and streptococcal toxic shock syndrome. The objective of this study was to compare molecular emm typing and pulsed field gel electrophoresis (PFGE) with multiple-locus variable-number tandem-repeat analysis (MLVA) for genotyping of Chinese S. pyogenes isolates. Molecular emm typing and PFGE were performed using standard protocols. Seven variable number tandem repeat (VNTR) loci reported in a previous study were used to genotype 169 S. pyogenes geographically-diverse isolates from China isolated from a variety of disease syndromes. Multiple-locus variable-number tandem-repeat analysis provided greater discrimination between isolates when compared to emm typing and PFGE. Removal of a single VNTR locus (Spy2) reduced the sensitivity by only 0.7%, which suggests that Spy2 was not informative for the isolates screened. The results presented support the use of MLVA as a powerful epidemiological tool for genotyping S. pyogenes clinical isolates. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. A Key Enzyme of the NAD+Salvage Pathway in Thermus thermophilus: Characterization of Nicotinamidase and the Impact of Its Gene Deletion at High Temperatures.

    Science.gov (United States)

    Taniguchi, Hironori; Sungwallek, Sathidaphorn; Chotchuang, Phatcharin; Okano, Kenji; Honda, Kohsuke

    2017-09-01

    NAD (NAD + ) is a cofactor related to many cellular processes. This cofactor is known to be unstable, especially at high temperatures, where it chemically decomposes to nicotinamide and ADP-ribose. Bacteria, yeast, and higher organisms possess the salvage pathway for reconstructing NAD + from these decomposition products; however, the importance of the salvage pathway for survival is not well elucidated, except for in pathogens lacking the NAD + de novo synthesis pathway. Herein, we report the importance of the NAD + salvage pathway in the thermophilic bacterium Thermus thermophilus HB8 at high temperatures. We identified the gene encoding nicotinamidase (TTHA0328), which catalyzes the first reaction of the NAD + salvage pathway. This recombinant enzyme has a high catalytic activity against nicotinamide ( K m of 17 μM, k cat of 50 s -1 , k cat / K m of 3.0 × 10 3 s -1 · mM -1 ). Deletion of this gene abolished nicotinamide deamination activity in crude extracts of T. thermophilus and disrupted the NAD + salvage pathway in T. thermophilus Disruption of the salvage pathway led to the severe growth retardation at a higher temperature (80°C), owing to the drastic decrease in the intracellular concentrations of NAD + and NADH. IMPORTANCE NAD + and other nicotinamide cofactors are essential for cell metabolism. These molecules are unstable and decompose, even under the physiological conditions in most organisms. Thermophiles can survive at high temperatures where NAD + decomposition is, in general, more rapid. This study emphasizes that NAD + instability and its homeostasis can be one of the important factors for thermophile survival in extreme temperatures. Copyright © 2017 American Society for Microbiology.

  14. Competition and coexistence between Streptococcus mutans and Streptococcus sanguinis in the dental biofilm.

    Science.gov (United States)

    Kreth, Jens; Merritt, Justin; Shi, Wenyuan; Qi, Fengxia

    2005-11-01

    The human mucosal surface is colonized by the indigenous microflora, which normally maintains an ecological balance among different species. Certain environmental or biological factors, however, may trigger disruption of this balance, leading to microbial diseases. In this study, we used two oral bacterial species, Streptococcus mutans and Streptococcus sanguinis (formerly S. sanguis), as a model to probe the possible mechanisms of competition/coexistence between different species which occupy the same ecological niche. We show that the two species engage in a multitude of antagonistic interactions temporally and spatially; occupation of a niche by one species precludes colonization by the other, while simultaneous colonization by both species results in coexistence. Environmental conditions, such as cell density, nutritional availability, and pH, play important roles in determining the outcome of these interactions. Genetic and biochemical analyses reveal that these interspecies interactions are possibly mediated through a well-regulated production of chemicals, such as bacteriocins (produced by S. mutans) and hydrogen peroxide (produced by S. sanguinis). Consistent with the phenotypic characteristics, production of bacteriocins and H2O2 are regulated by environmental conditions, as well as by juxtaposition of the two species. These sophisticated interspecies interactions could play an essential part in balancing competition/coexistence within multispecies microbial communities.

  15. In Vitro Effect of Zingiber officinale Extract on Growth of Streptococcus mutans and Streptococcus sanguinis

    Directory of Open Access Journals (Sweden)

    Arash Azizi

    2015-01-01

    Full Text Available Background and Objectives. Tooth decay is an infectious disease of microbial origin. Considering the increasing prevalence of antibiotic resistance due to their overuse and also their side effects, medicinal plants are now considered for use against bacterial infections. This study aimed to assess the effects of different concentrations of Zingiber officinale extract on proliferation of Streptococcus mutans and Streptococcus sanguinis in vitro. Materials and Methods. In this experimental study, serial dilutions of the extract were prepared in two sets of 10 test tubes for each bacterium (total of 20. Standard amounts of bacterial suspension were added; 100ƛ of each tube was cultured on prepared solid agar plates and incubated at 37°C for 24 hours. Serial dilutions of the extract were prepared in another 20 tubes and 100ƛ of each tube was added to blood agar culture medium while being prepared. The mixture was transferred to the plates. The bacteria were inoculated on plates and incubated as described. Results. The minimum inhibitory concentration (MIC was 0.02 mg/mL for S. mutans and 0.3 mg/mL for S. sanguinis. The minimum bactericidal concentration (MBC was 0.04 mg for S. mutans and 0.6 mg for S. sanguinis. Conclusion. Zingiber officinale extract has significant antibacterial activity against S. mutans and S. sanguinis cariogenic microorganisms.

  16. Inhibitory effects of antiseptic mouthrinses on Streptococcus mutans, Streptococcus sanguinis and Lactobacillus acidophilus.

    Science.gov (United States)

    Evans, A; Leishman, S J; Walsh, L J; Seow, W K

    2015-06-01

    Oral antiseptics are valuable in controlling oral infections caused by cariogenic bacteria. The aim of this study was to investigate the effects of mouthrinses and pure antiseptic compounds on Streptococcus mutans and non-mutans bacteria (Streptococcus sanguinis and Lactobacillus acidophilus). The agar diffusion assay was employed to determine bacterial growth inhibition. Commercial mouthrinses containing chlorhexidine gluconate (0.2%), cetylpyridinium chloride (0.05%) and sodium fluoride (0.05%) produced statistically similar growth inhibition of S. mutans, S. sanguinis and L. acidophilus (with zones of inhibition ranging from 7.56 ± 0.52 mm to 7.39 ± 0.53 mm, 17.44 ± 0.94 mm to 18.31 ± 0.62 mm and 8.61 ± 1.43 to 8.67 ± 1.43 mm respectively, p > 0.05). The chlorhexidine mouthwash produced the greatest mean growth inhibition of S. sanguinis and S. mutans compared to all other mouthrinses tested (p < 0.01). The minimum concentrations at which inhibition against S. mutans could be detected were chlorhexidine gluconate at 0.005% (wt/vol), cetylpyridinium chloride 0.01% (wt/ vol), povidone iodine 10% (wt/vol) and sodium hypochlorite 0.5% (vol/vol). Chlorhexidine (0.01%), cetylpyridinium chloride (0.01%), povidone iodine (10%) and sodium hypochlorite (0.5%) are effective at inhibiting the growth of S. mutans, S. sanguinis and L. acidophilus. © 2015 Australian Dental Association.

  17. Interaction of anti-kojibiose antibody with the lipoteichoic acids from Streptococcus faecalis and Streptococcus faecium.

    Science.gov (United States)

    Kessler, R E; Duke, J; Goldstein, I J

    1984-10-01

    Antisera prepared in rabbits by immunization with p-aminophenyl beta-kojibioside conjugated to bovine serum albumin (antikojibiose sera), readily agglutinated whole cells of Streptococcus faecalis or Streptococcus faecium, and showed specific reactions with the lipoteichoic acids (LTAs) of these streptococci by passive hemagglutination, microscale enzyme-linked immunosorbent assay, and crossed immunoelectrophoresis. The interaction of the antikojibiose sera with the LTAs was inhibited best by kojibiose [alpha-D-glucopyranosyl-(1----2)-D-glucose], somewhat less by the dextran from which the kojibiose was prepared, and not measurably by maltose [alpha-D-glucopyranosyl-(1----4)-D-glucose]. The sera reacted only minimally in only the most sensitive assay (microscale enzyme-linked immunosorbent assay) with LTA from group A streptococci (this LTA contains a single kojibiosyl residue as part of the glycolipid moiety of the molecule and failed to react with the Lactobacillus fermentum LTA which is substituted with alpha-D-galactopyranosyl-(1----2)-D -glucosyl units.

  18. Peroxidase reaction as a parameter for discrimination of Streptococcus mutans and Streptococcus sobrinus.

    Science.gov (United States)

    Rupf, S; Merte, K; Eschrich, K; Stösser, L; Kneist, S

    2001-01-01

    425 strains of mutans streptococci and 12 reference strains were investigated by membrane fatty acid spectra (MFAS) and peroxidase reaction (PR) after aerobic and anaerobic incubation. 423 strains were identified as Streptococcus mutans. The remaining 2 strains were identified as Streptococcus sobrinus. The PR of 29 strains was doubtful; immediately after anaerobic incubation a negative PR changed into a slightly positive PR. To test the diagnostic value of PR the strains were additionally investigated by means of species-specific polymerase chain reactions (PCR). The species-specific PCRs were developed on the basis of the respective genes of 16S rRNA of the pathogens S. mutans and S. sobrinus. Specificity and sensitivity were tested on reference strains (n = 17) and negative control strains (n = 39). The results of this investigation showed that an anaerobic incubation regime could lead to false-positive (S. mutans) or false-negative (S. sobrinus) PR. The 425 MS strains were classified as either S. mutans (n = 420) or S. sobrinus (n = 5). The findings on the reference strains required a reclassification of S. mutans V 100 into S. sobrinus V 100. Summarising, it is possible now to differentiate strains of mutans streptococci by MFAS and PR after aerobic incubation.

  19. Adherence of Streptococcus mutans and Streptococcus sanguis to salivary components bound to glass.

    Science.gov (United States)

    Stinson, M W; Jinks, D C; Merrick, J M

    1981-01-01

    Adherence of radiolabeled Streptococcus mutans and Streptococcus sanguis to saliva-treated glass surfaces was studied under conditions which minimized bacteria-glass interactions. Treatment of glass with an alkylsilane solution decreased nonspecific bacterial adherence and enhanced adsorption of radiolabeled salivary components to these surfaces. Addition of Triton X-100 to the bacterial suspensions also reduced nonspecific adherence to siliconized glass, but did not affect adherence to salivary components attached to siliconized glass. Calcium stimulated S. mutans adherence to saliva-free glass, but inhibited adherence to saliva-treated glass. S. sanguis adherence to either saliva-free or saliva-treated glass was inhibited slightly at high calcium ion concentrations. Adherence of streptococci to saliva-treated glass exhibited saturation kinetics, and the numbers of binding sites on the experimental salivary pellicle and the affinity constants for bacteria-saliva attachment were determined. Preincubation of the streptococci with whole saliva decreased their capacity to adhere to saliva-treated glass, but not to saliva-free glass. Bacteria adherent to saliva-treated glass surfaces were readily desorbed by washing with saliva. The addition of homologous antisera, ammonium sulfate-precipitated immunoglobulins, or Fab fragments to the bacterial suspensions inhibited cell adherence to saliva-treated glass. PMID:7251139

  20. Postantibiotic effects and postantibiotic sub-MIC effects of amoxicillin on Streptococcus gordonii and Streptococcus sanguis.

    Science.gov (United States)

    Lee, S Y

    2000-10-01

    Amoxicillin is one of the most frequently recommended antibiotics for prophylaxis of infective endocarditis in dental/oral procedures. In this study, the postantibiotic effect (PAE), postantibiotic sub-MIC (PASME) and sub-MIC effect (SME) of amoxicillin on oral streptococci, Streptococcus gordonii and Streptococcus sanguis, which are two of the major etiological agents in infective endocarditis, were investigated. The PAE was induced by 10 x MIC of amoxicillin for 2 h and the antibiotic was eliminated by washing. The PASMEs were studied by addition of 0.1, 0.2 and 0.3 x MICs during the postantibiotic phase of the bacteria, and the SMEs were studied by exposing bacteria to amoxicillin at the sub-MICs only. The PAE of amoxicillin was 2.0 h with S. gordonii DL1 and 0.7 h with S. sanguis MPC1. The PASME and SME of amoxicillin were observed both for S. gordonii DL1 and for S. sanguis MPC1. However, the durations of effects for S. sanguis MPC1 were shorter than those for S. gordonii DL1. The PASME values for both strains increased as the concentration of amoxicillin increased. The PASME values for both strains were substantially longer than the SME values. The present study illustrates the existence of PAE, PASME and SME for amoxicillin against S. gordonii and S. sanguis, thereby extending the pharmacodynamic advantages of amoxicillin for these bacteria in the prophylaxis procedures of infective endocarditis.

  1. Effects of acidification on growth and glycolysis of Streptococcus sanguis and Streptococcus mutans.

    Science.gov (United States)

    Takahashi, N; Horiuchi, M; Yamada, T

    1997-04-01

    After carbohydrate intake, pH in dental plaque decreases rapidly and reaches about 4 within a few minutes. The acidification not only promotes demineralization of tooth surface but can also cause damage to bacteria in dental plaque. We, therefore, investigated the effect of acidification on the dental plaque bacteria Streptococcus sanguis and Streptococcus mutans. At pH 4.0 and 4.2, both growth and glycolytic activities in these streptococci were repressed. Prolonged acidification (for 60 min at pH 4.0) not only repressed both growth and glycolytic activities but also impaired them in S. sanguis cells with concomitant inactivation of the glycolytic enzymes, hexokinase, phosphofructokinase, glyceraldehydephosphate dehydrogenase and enolase. The impaired abilities of glycolysis and growth recovered following incubation at pH 7.0 for 80-90 min, and this was accompanied by reactivation of the glycolytic enzymes. On the other hand, these impairments were not observed in S. mutans cells exposed to prolonged acidification. These results indicate that the low pH frequently occurring in dental plaque may transiently impair streptococcal glycolysis and growth and that S. mutans is more durable to the acidification than S. sanguis.

  2. In Vitro Effect of Zingiber officinale Extract on Growth of Streptococcus mutans and Streptococcus sanguinis.

    Science.gov (United States)

    Azizi, Arash; Aghayan, Shabnam; Zaker, Saeed; Shakeri, Mahdieh; Entezari, Navid; Lawaf, Shirin

    2015-01-01

    Background and Objectives. Tooth decay is an infectious disease of microbial origin. Considering the increasing prevalence of antibiotic resistance due to their overuse and also their side effects, medicinal plants are now considered for use against bacterial infections. This study aimed to assess the effects of different concentrations of Zingiber officinale extract on proliferation of Streptococcus mutans and Streptococcus sanguinis in vitro. Materials and Methods. In this experimental study, serial dilutions of the extract were prepared in two sets of 10 test tubes for each bacterium (total of 20). Standard amounts of bacterial suspension were added; 100ƛ of each tube was cultured on prepared solid agar plates and incubated at 37°C for 24 hours. Serial dilutions of the extract were prepared in another 20 tubes and 100ƛ of each tube was added to blood agar culture medium while being prepared. The mixture was transferred to the plates. The bacteria were inoculated on plates and incubated as described. Results. The minimum inhibitory concentration (MIC) was 0.02 mg/mL for S. mutans and 0.3 mg/mL for S. sanguinis. The minimum bactericidal concentration (MBC) was 0.04 mg for S. mutans and 0.6 mg for S. sanguinis. Conclusion. Zingiber officinale extract has significant antibacterial activity against S. mutans and S. sanguinis cariogenic microorganisms.

  3. Streptococcus mutans and Streptococcus sobrinus are able to adhere and invade human gingival fibroblast cell line.

    Science.gov (United States)

    Berlutti, F; Catizone, A; Ricci, G; Frioni, A; Natalizi, T; Valenti, P; Polimeni, A

    2010-01-01

    Streptococcus mutans and Streptococcus sobrinus, the principal etiologic agents of caries decay of teeth, are generally acquired in oral cavity at the moment of tooth eruption. However, as S. mutans has been detected in oral cavity of predentate children, the eruption of teeth seems not to be a necessary prerequisite, suggesting that this species may be not confined to dental plaque. Here, we evaluate the ability of S. mutans and S. sobrinus in planktonic and biofilm lifestyle to adhere, invade and survive within human gingival fibroblast (HGF-1) cells. Planktonic and biofilm streptococci adhered and invaded host cells to different extents, showing higher efficiencies of biofilm than planktonic counterparts. Moreover, planktonic and biofilm streptococci showed the same percentage of survival within host cells. Transmission electron and confocal microscopy observations confirmed intracellular localization of planktonic and biofilm bacteria. The adhesion, invasion and survival abilities within human oral cells may be considered S. mutans and S. sobrinus virulence mechanisms to colonize and persist in the oral cavity in the absence of tooth surface.

  4. Mutations in conserved helix 69 of 23S rRNA of Thermus thermophilus that affect capreomycin resistance but not posttranscriptional modifications

    DEFF Research Database (Denmark)

    Monshupanee, Tanakarn; Gregory, Steven T; Douthwaite, Stephen

    2008-01-01

    of previously reported capreomycin resistance base substitutions. Capreomycin resistance in other bacteria has been shown to result from inactivation of the TlyA methyltransferase which 2'-O methylates C1920 of 23S rRNA. Inactivation of the tlyA gene in T. thermophilus does not affect its sensitivity...... to capreomycin. Finally, none of the mutations in helix 69 interferes with methylation at C1920 or with pseudouridylation at positions 1911 and 1917. We conclude that the resistance phenotype is a consequence of structural changes introduced by the mutations....

  5. ns-μs Time-Resolved Step-Scan FTIR of ba3 Oxidoreductase from Thermus thermophilus: Protonic Connectivity of w941-w946-w927

    Directory of Open Access Journals (Sweden)

    Antonis Nicolaides

    2016-09-01

    Full Text Available Time-resolved step-scan FTIR spectroscopy has been employed to probe the dynamics of the ba3 oxidoreductase from Thermus thermophilus in the ns-μs time range and in the pH/pD 6–9 range. The data revealed a pH/pD sensitivity of the D372 residue and of the ring-A propionate of heme a3. Based on the observed transient changes a model in which the protonic connectivity of w941-w946-927 to the D372 and the ring-A propionate of heme a3 is described.

  6. 21 CFR 866.3720 - Streptococcus spp. exo-enzyme reagents.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Streptococcus spp. exo-enzyme reagents. 866.3720... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3720 Streptococcus spp. exo-enzyme reagents. (a) Identification. Streptococcus spp. exoenzyme reagents are devices used...

  7. 77 FR 26014 - Prospective Grant of Exclusive License: P4 Peptide From Streptococcus Pneumoniae

    Science.gov (United States)

    2012-05-02

    ... Prospective Grant of Exclusive License: P4 Peptide From Streptococcus Pneumoniae AGENCY: Technology Transfer... polysaccharide vaccine conjugate for prevention of Streptococcus pneumonia infection in humans'') to practice the... ``Functional Epitopes of Streptococcus Pneumoniae PsaA Antigen and Uses Thereof,'' filed 7/ 18/2008, claiming...

  8. Complete genome sequence and comparative genomic analysis of an emerging human pathogen, serotype V Streptococcus agalactiae

    NARCIS (Netherlands)

    Tettelin, H; Masignani, [No Value; Cieslewicz, MJ; Eisen, JA; Peterson, S; Paulsen, IT; Nelson, KE; Margarit, [No Value; Read, TD; Madoff, LC; Beanan, MJ; Brinkac, LM; Daugherty, SC; DeBoy, RT; Durkin, AS; Kolonay, JF; Madupu, R; Lewis, MR; Radune, D; Fedorova, NB; Scanlan, D; Khouri, H; Mulligan, S; Carty, HA; Cline, RT; Van Aken, SE; Gill, J; Scarselli, M; Mora, M; Iacobini, ET; Brettoni, C; Galli, G; Mariani, M; Vegni, F; Maione, D; Rinaudo, D; Rappuoli, R; Telford, JL; Kasper, DL; Grandi, G; Fraser, CM

    2002-01-01

    The 2,160,267 bp genome sequence of Streptococcus agalactiae, the leading cause of bacterial sepsis, pneumonia, and meningitis in neonates in the U.S. and Europe, is predicted to encode 2,175 genes. Genome comparisons among S. agalactiae, Streptococcus pneumoniae, Streptococcus pyogenes, and the

  9. Evaluación antibacteriana de extracto de mosquera (Croton elegans.) frente a: (Staphylococcus aureus ATCC: 25923, Streptococcus pyogenes ATCC: 19615, Streptococcus pneumoniae ATCC: 49619 y Streptococcus mutans ATCC: 25175), patógenos de enfermedades respiratorias

    OpenAIRE

    Ordóñez Rea, Omar Leonardo

    2016-01-01

    In our country there is a variety of medicinal plants some of them without scientific studies and little investigation that is the case of the species Croton elegans, the ethnobotanical use of it allows us to deduce some antimicrobial activity, this being the fundament that determined the essay on some respiratory disease causing bacteria such as: Staphylococcus aureus ATCC 25923 Streptococcus pneumoniae ATCC (49619), Streptococcus mutans ATCC (25175) y Streptococcus pyoge...

  10. Sulfur Metabolism of Hydrogenovibrio thermophilus Strain S5 and Its Adaptations to Deep-Sea Hydrothermal Vent Environment

    Directory of Open Access Journals (Sweden)

    Lijing Jiang

    2017-12-01

    Full Text Available Hydrogenovibrio bacteria are ubiquitous in global deep-sea hydrothermal vents. However, their adaptations enabling survival in these harsh environments are not well understood. In this study, we characterized the physiology and metabolic mechanisms of Hydrogenovibrio thermophilus strain S5, which was first isolated from an active hydrothermal vent chimney on the Southwest Indian Ridge. Physiological characterizations showed that it is a microaerobic chemolithomixotroph that can utilize sulfide, thiosulfate, elemental sulfur, tetrathionate, thiocyanate or hydrogen as energy sources and molecular oxygen as the sole electron acceptor. During thiosulfate oxidation, the strain produced extracellular sulfur globules 0.7–6.0 μm in diameter that were mainly composed of elemental sulfur and carbon. Some organic substrates including amino acids, tryptone, yeast extract, casamino acids, casein, acetate, formate, citrate, propionate, tartrate, succinate, glucose and fructose can also serve as carbon sources, but growth is weaker than under CO2 conditions, indicating that strain S5 prefers to be chemolithoautotrophic. None of the tested organic carbons could function as energy sources. Growth tests under various conditions confirmed its adaption to a mesophilic mixing zone of hydrothermal vents in which vent fluid was mixed with cold seawater, preferring moderate temperatures (optimal 37°C, alkaline pH (optimal pH 8.0, microaerobic conditions (optimal 4% O2, and reduced sulfur compounds (e.g., sulfide, optimal 100 μM. Comparative genomics showed that strain S5 possesses more complex sulfur metabolism systems than other members of genus Hydrogenovibrio. The genes encoding the intracellular sulfur oxidation protein (DsrEF and assimilatory sulfate reduction were first reported in the genus Hydrogenovibrio. In summary, the versatility in energy and carbon sources, and unique physiological properties of this bacterium have facilitated its adaptation to deep

  11. Crystal structure analysis of ornithine transcarbamylase from Thermus thermophilus --HB8 provides insights on the plasticity of the active site.

    Science.gov (United States)

    Sundaresan, Ramya; Ebihara, Akio; Kuramitsu, Seiki; Yokoyama, Shigeyuki; Kumarevel, Thirumananseri; Ponnuraj, Karthe

    2015-09-18

    The enzymatic biosynthesis of L-arginine involves complex, sequential action of many enzymes and ornithine transcarbamylase (OTCase) is one of the essential enzymes in the pathway. In mammals OTCase is part of the urea cycle. Arginine is used in a variety of pharmaceutical and industrial applications and therefore engineering arginine biosynthesis pathway for overproduction of arginine has gained importance. On the other hand, it was found that detrimental mutations in the human OTCase gene resulted clinical hyperammonemia, with subsequent neurological damage. Therefore a better understanding of the structure-function relationship of this enzyme from various sources could be useful for modifying its enzymatic action. Here we report the structure of ornithine transcarbamylase of Thermus thermophilus HB8 (aTtOTCase) at 2.0 Å resolution. On comparison with its homologs, aTtOTCase showed maximum variation at the substrate binding loops namely 80s and SMG/240s loops. The active site geometry of aTtOTCase is unique among its homologs where the side chain of certain residues (Leu57, Arg58 and Arg288) is oriented differently. To study the structural insights of substrate binding in aTtOTCase, docking of carbamoyl phosphate (CP) and ornithine (Orn) was carried out sequentially. Both substrates were unable to bind in a proper orientation in the active site pocket and this could be due to the differently oriented side chains. This suggests that the active site geometry should also undergo fine tuning besides the large structural changes as the enzyme switches from completely open to a substrate bound closed state. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Crystal structure studies of NADP{sup +} dependent isocitrate dehydrogenase from Thermus thermophilus exhibiting a novel terminal domain

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S.M. [Department of Studies in Physics, University of Mysore, Mysore 570 006 (India); Pampa, K.J. [Department of Studies in Microbiology, University of Mysore, Mysore 570 006 (India); Manjula, M. [Department of Studies in Physics, University of Mysore, Mysore 570 006 (India); Abdoh, M.M.M. [Department of Physics, Faculty of Science, An-Najah National University, Nablus, West Bank, Palestine (Country Unknown); Kunishima, Naoki [Advanced Protein Crystallography Research Group, RIKEN SPring-8 Center, Harima Institute, Hyogo 679-5148 (Japan); Lokanath, N.K., E-mail: lokanath@physics.uni-mysore.ac.in [Department of Studies in Physics, University of Mysore, Mysore 570 006 (India)

    2014-06-20

    Highlights: • We determined the structure of isocitrate dehydrogenase with citrate and cofactor. • The structure reveals a unique novel terminal domain involved in dimerization. • Clasp domain shows significant difference, and catalytic residues are conserved. • Oligomerization of the enzyme is quantized with subunit-subunit interactions. • Novel domain of this enzyme is classified as subfamily of the type IV. - Abstract: NADP{sup +} dependent isocitrate dehydrogenase (IDH) is an enzyme catalyzing oxidative decarboxylation of isocitrate into oxalosuccinate (intermediate) and finally the product α-ketoglutarate. The crystal structure of Thermus thermophilus isocitrate dehydrogenase (TtIDH) ternary complex with citrate and cofactor NADP{sup +} was determined using X-ray diffraction method to a resolution of 1.80 Å. The overall fold of this protein was resolved into large domain, small domain and a clasp domain. The monomeric structure reveals a novel terminal domain involved in dimerization, very unique and novel domain when compared to other IDH’s. And, small domain and clasp domain showing significant differences when compared to other IDH’s of the same sub-family. The structure of TtIDH reveals the absence of helix at the clasp domain, which is mainly involved in oligomerization in other IDH’s. Also, helices/beta sheets are absent in the small domain, when compared to other IDH’s of the same sub family. The overall TtIDH structure exhibits closed conformation with catalytic triad residues, Tyr144-Asp248-Lys191 are conserved. Oligomerization of the protein is quantized using interface area and subunit–subunit interactions between protomers. Overall, the TtIDH structure with novel terminal domain may be categorized as a first structure of subfamily of type IV.

  13. Maribacter thermophilus sp. nov., isolated from an algal bloom in an intertidal zone, and emended description of the genus Maribacter.

    Science.gov (United States)

    Hu, Jing; Yang, Qi-Qi; Ren, Yi; Zhang, Wen-Wu; Zheng, Gang; Sun, Cong; Pan, Jie; Zhu, Xu-Fen; Zhang, Xin-Qi; Wu, Min

    2015-01-01

    A novel facultatively anaerobic, Gram-stain-negative bacterium, designated strain HT7-2(T), was isolated from Ulva prolifera collected from the intertidal zone of Qingdao sea area, China, during its bloom. Cells were rod-shaped (1.9-3.5×0.4-0.6 µm), non-sporulating and motile by gliding. Strain HT7-2(T) was able to grow at 4-50 °C (optimum 40-42 °C), pH 5.5-8.5 (optimum pH 7.0), 0-8 % (w/v) NaCl (optimum 2-3 %) and 0.5-10 % (w/v) sea salts (optimum 2.5 %). The genomic DNA G+C content was 38.8 mol%. The phylogenetic analysis based on 16S rRNA gene sequences revealed that strain HT7-2(T) belonged to the genus Maribacter with sequence similarity values of 94.5-96.6 %, and was most closely related to Maribacter aestuarii GY20(T) (96.6%). Chemotaxonomic analysis showed that the main isoprenoid quinone was MK-6 and the major fatty acids were iso-C15:0 and unknown equivalent chain-length 13.565. The polar lipids of strain HT7-2(T) consisted of one phosphatidylethanolamine, four unidentified lipids and one unidentified aminolipid. On the basis of the phenotypic, phylogenetic and chemotaxonomic characteristics, strain HT7-2(T) ( =CGMCC 1.12207(T) =JCM 18466(T)) is concluded to represent a novel species of the genus Maribacter, for which the name Maribacter thermophilus sp. nov. is proposed. An emended description of the genus Maribacter is also proposed. © 2015 IUMS.

  14. Streptococcus gordonii septic arthritis : two cases and review of literature

    Directory of Open Access Journals (Sweden)

    Yombi Jean cyr

    2012-09-01

    Full Text Available Abstract Background Despite advances in antimicrobial and surgical therapy, septic arthritis remains a rheumatologic emergency that can lead to rapid joint destruction and irreversible loss of function. In adults, Staphylococcus aureus is the most common microorganism isolated from native joints. Streptococcus gordonii is a prominent member of the viridans group of oral bacteria and is among the bacteria most frequently identified as being primary agent of subacute bacterial endocarditis. To the best of our knowledge, Streptococcus gordonii has not yet been described as agent of septic arthritis. Case Presentation We describe here two cases of septic arthritis due to Streptococcus gordonii. It gives us an opportunity to review epidemiology, diagnosis criteria and management of septic arthritis. Conclusion Although implication of S. gordonii as aetiologic agent of subacute endocarditis is well known, this organism is a rare cause of septic arthritis. In this case, the exclusion of associated endocarditis is warranted.

  15. [Bilateral breast bacterial cellulite secondary to Streptococcus agalactiae septicemia].

    Science.gov (United States)

    Conscience, I; Perceau, G; Le Berruyer, P-Y; Bernard, P

    2006-02-01

    We report a case of group B streptococcal septicemia of digestive origin with secondary bilateral breast dermal-hypodermal localization. A 71 year-old woman with a past history of bilateral breast cancer treated by conservation therapy was hospitalized because of the sudden occurrence of two clearly delimited, inflammatory, dermal-hypodermal cutaneous plaques located on each breast, associated with fever (39 degrees C), 4 days after a colonoscopy. Further investigations eliminated carcinomatous mastitis and blood cultures were positive for group B beta-hemolytic streptococcus (Streptococcus agalactiae). Histological examination of a sigmoid polyp revealed a tubular adenocarcinoma. We report the first documented case of secondary dermal-hypodermal bacterial skin infection (cellulitis) due to group B beta-hemolytic streptococcus. The occurrence after colonoscopy examination, chronology of clinical features, bilaterality and positive blood cultures are arguments in favor of the secondary nature of the skin infection process.

  16. An outbreak of Streptococcus pneumoniae in an Italian nursing home.

    Directory of Open Access Journals (Sweden)

    Riccardo Papalia

    2015-09-01

    Full Text Available Streptococcus pneumoniae is the main cause of community-acquired pneumonia worldwide; pneumonia occurs sporadically in most cases, but rare outbreaks have been reported. We  describe an outbreak occurred in a 21-guests nursing home for elders in Aosta (Italy; outbreak occurred in april 2014 over a 2 weeks period, resulting in 12 out 20 guests affected (all with high fever and respiratory symptoms, two deaths (at home, nine patients referred  to Hospital Emergency Room, and eight admissions. Urinary streptococcus antigen was positive in seven out of eight patient tested. None of the nursing home guests were vaccinated against Streptococcus pneumoniaeThe Hospital Medical Direction and Public Health Service gave support and adopted strategies to contain the outbreak spread.We underline the need for pneumococcal vaccination in nursing homes/ Long-term care facilities; accurate check of hygiene behaviours in those setting is also mandatory.   

  17. Chlorophyll mediated photodynamic inactivation of blue laser on Streptococcus mutans

    Science.gov (United States)

    Astuti, Suryani Dyah; Zaidan, A.; Setiawati, Ernie Maduratna; Suhariningsih

    2016-03-01

    Photodynamic inactivation is an inactivation method in microbial pathogens that utilize light and photosensitizer. This study was conducted to investigate photodynamic inactivation effects of low intensity laser exposure with various dose energy on Streptococcus mutans bacteria. The photodynamic inactivation was achieved with the addition of chlorophyll as photosensitizers. To determine the survival percentage of Streptococcus mutans bacteria after laser exposure, the total plate count method was used. For this study, the wavelength of the laser is 405 nm and variables of energy doses are 1.44, 2.87, 4.31, 5.74, 7.18, and 8.61 in J/cm2. The results show that exposure to laser with energy dose of 7.18 J/cm2 has the best photodynamic inactivation with a decrease of 78% in Streptococcus

  18. [Streptococcus intermedius: a rare cause of brain abscess in children].

    Science.gov (United States)

    Jouhadi, Z; Sadiki, H; Hafid, I; Najib, J

    2013-03-01

    Streptococcus intermedius is a member of the Streptococcus anginosus group, also known as the Streptococcus milleri group. Although this is a commensal agent of the mouth and upper airways, it has been recognized as an important pathogen in the formation of abscesses. However, it has rarely been involved in the formation of brain abscess in children. We report 4 pediatric cases of brain abscess caused by S. intermedius. Three boys and 1 girl, all aged over 2 years, were admitted for a febrile meningeal syndrome and seizures, caused by a S. intermedius brain abscess. Diagnosis was obtained by brain imaging combined with culture of cerebrospinal fluid. The outcome was favorable after antibiotic therapy and abscess puncture. S. intermedius should be considered a potential pathogen involved in the development of brain abscess in children. Copyright © 2013. Published by Elsevier SAS.

  19. Nonencapsulated Streptococcus pneumoniae: Emergence and Pathogenesis

    Directory of Open Access Journals (Sweden)

    Lance E. Keller

    2016-05-01

    Full Text Available While significant protection from pneumococcal disease has been achieved by the use of polysaccharide and polysaccharide-protein conjugate vaccines, capsule-independent protection has been limited by serotype replacement along with disease caused by nonencapsulated Streptococcus pneumoniae (NESp. NESp strains compose approximately 3% to 19% of asymptomatic carriage isolates and harbor multiple antibiotic resistance genes. Surface proteins unique to NESp enhance colonization and virulence despite the lack of a capsule even though the capsule has been thought to be required for pneumococcal pathogenesis. Genes for pneumococcal surface proteins replace the capsular polysaccharide (cps locus in some NESp isolates, and these proteins aid in pneumococcal colonization and otitis media (OM. NESp strains have been isolated from patients with invasive and noninvasive pneumococcal disease, but noninvasive diseases, specifically, conjunctivitis (85% and OM (8%, are of higher prevalence. Conjunctival strains are commonly of the so-called classical NESp lineages defined by multilocus sequence types (STs ST344 and ST448, while sporadic NESp lineages such as ST1106 are more commonly isolated from patients with other diseases. Interestingly, sporadic lineages have significantly higher rates of recombination than classical lineages. Higher rates of recombination can lead to increased acquisition of antibiotic resistance and virulence factors, increasing the risk of disease and hindering treatment. NESp strains are a significant proportion of the pneumococcal population, can cause disease, and may be increasing in prevalence in the population due to effects on the pneumococcal niche caused by pneumococcal vaccines. Current vaccines are ineffective against NESp, and further research is necessary to develop vaccines effective against both encapsulated and nonencapsulated pneumococci.

  20. Effect of irradiation on the streptococcus mutans

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Ki Dong; Kim, Gyu Tae; Choi, Yong Suk; Hwang, Eui Hwan [Kyung Hee Univ., Seoul (Korea, Republic of)

    2007-03-15

    To observe direct effect of irradiation on cariogenic Streptococcus mutans. S. mutans GS5 was exposed to irradiation with a single absorbed dose of 10, 20, 30, and 40 Gy. Viability and changes in antibiotic sensitivity, morphology, transcription of virulence factors, and protein profile of bacterium after irradiation were examined by pour plate, disc diffusion method, Transmission electron microscopy. RT-PCR, and SDS-PAGE, respectively. After irradiation with 10 and 20 Gy, viability of S. mutans was reduced. Further increase in irradiation dose, however, did not affect the viability of the remaining cells of S. mutans. Irradiated S. mutans was found to have become sensitive to antibiotics. In particular, the bacterium irradiated with 40 Gy increased its susceptibility to cefotaxime, penicillin, and tetracycline. Under the transmission electron microscope, number of morphologically abnormal cells was increased as the irradiation dose was increased. S. mutans irradiated with 10 Gy revealed a change in the cell wall and cell membrane. As irradiation dose was increased. a higher number of cells showed thickened cell wall and cell membrane and lysis, and appearance of ghost cells was noticeable. In RT-PCR, no difference was detected in expression of gtfB and spaP between cells with and without irradiation of 40 Gy. In SDS-PAGE, proteins with higher molecular masses were gradually diminished as irradiation dose was increased. These results suggest that irradiation affects the cell integrity of S. mutans, as observed by SDS-PAGE, and as manifested by the change in cell morphology, antibiotic sensitivity, and eventually viability of the bacterium.

  1. Thermoregulation of Capsule Production by Streptococcus pyogenes

    Science.gov (United States)

    Kang, Song Ok; Wright, Jordan O.; Tesorero, Rafael A.; Lee, Hyunwoo; Beall, Bernard; Cho, Kyu Hong

    2012-01-01

    The capsule of Streptococcus pyogenes serves as an adhesin as well as an anti-phagocytic factor by binding to CD44 on keratinocytes of the pharyngeal mucosa and the skin, the main entry sites of the pathogen. We discovered that S. pyogenes HSC5 and MGAS315 strains are further thermoregulated for capsule production at a post-transcriptional level in addition to the transcriptional regulation by the CovRS two-component regulatory system. When the transcription of the hasABC capsular biosynthetic locus was de-repressed through mutation of the covRS system, the two strains, which have been used for pathogenesis studies in the laboratory, exhibited markedly increased capsule production at sub-body temperature. Employing transposon mutagenesis, we found that CvfA, a previously identified membrane-associated endoribonuclease, is required for the thermoregulation of capsule synthesis. The mutation of the cvfA gene conferred increased capsule production regardless of temperature. However, the amount of the capsule transcript was not changed by the mutation, indicating that a post-transcriptional regulator mediates between CvfA and thermoregulated capsule production. When we tested naturally occurring invasive mucoid strains, a high percentage (11/53, 21%) of the strains exhibited thermoregulated capsule production. As expected, the mucoid phenotype of these strains at sub-body temperature was due to mutations within the chromosomal covRS genes. Capsule thermoregulation that exhibits high capsule production at lower temperatures that occur on the skin or mucosal surface potentially confers better capability of adhesion and invasion when S. pyogenes penetrates the epithelial surface. PMID:22615992

  2. Capsular Polysaccharide Expression in Commensal Streptococcus Species: Genetic and Antigenic Similarities to Streptococcus pneumoniae.

    Science.gov (United States)

    Skov Sørensen, Uffe B; Yao, Kaihu; Yang, Yonghong; Tettelin, Hervé; Kilian, Mogens

    2016-11-15

    Expression of a capsular polysaccharide is considered a hallmark of most invasive species of bacteria, including Streptococcus pneumoniae, in which the capsule is among the principal virulence factors and is the basis for successful vaccines. Consequently, it was previously assumed that capsule production distinguishes S. pneumoniae from closely related commensals of the mitis group streptococci. Based on antigenic and genetic analyses of 187 mitis group streptococci, including 90 recognized serotypes of S. pneumoniae, we demonstrated capsule production by the Wzy/Wzx pathway in 74% of 66 S. mitis strains and in virtually all tested strains of S. oralis (subspecies oralis, dentisani, and tigurinus) and S. infantis Additional analyses of genomes of S. cristatus, S. parasanguinis, S. australis, S. sanguinis, S. gordonii, S. anginosus, S. intermedius, and S. constellatus revealed complete capsular biosynthesis (cps) loci in all strains tested. Truncated cps loci were detected in three strains of S. pseudopneumoniae, in 26% of S. mitis strains, and in a single S. oralis strain. The level of sequence identities of cps locus genes confirmed that the structural polymorphism of capsular polysaccharides in S. pneumoniae evolved by import of cps fragments from commensal Streptococcus species, resulting in a mosaic of genes of different origins. The demonstrated antigenic identity of at least eight of the numerous capsular polysaccharide structures expressed by commensal streptococci with recognized serotypes of S. pneumoniae raises concerns about potential misidentifications in addition to important questions concerning the consequences for vaccination and host-parasite relationships both for the commensals and for the pathogen. Expression of a capsular polysaccharide is among the principal virulence factors of Streptococcus pneumoniae and is the basis for successful vaccines against infections caused by this important pathogen. Contrasting with previous

  3. Streptococcus equi subsp zooepidemicus Invades and Survives in Epithelial Cells

    DEFF Research Database (Denmark)

    Skive, Bolette; Rohde, Manfred; Molinari, Gabriella

    2017-01-01

    Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) is an opportunistic pathogen of several species including humans. S. zooepidemicus is found on mucus membranes of healthy horses, but can cause acute and chronic endometritis. Recently S. zooepidemicus was found able to reside in the endo......Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) is an opportunistic pathogen of several species including humans. S. zooepidemicus is found on mucus membranes of healthy horses, but can cause acute and chronic endometritis. Recently S. zooepidemicus was found able to reside...

  4. Draft Genome Sequence of Type Strain Streptococcus gordonii ATCC 10558

    DEFF Research Database (Denmark)

    Rasmussen, Louise Hesselbjerg; Dargis, Rimtas; Christensen, Jens Jørgen Elmer

    2016-01-01

    Streptococcus gordonii ATCC 10558T was isolated from a patient with infective endocarditis in 1946 and announced as a type strain in 1989. Here, we report the 2,154,510-bp draft genome sequence of S. gordonii ATCC 10558T. This sequence will contribute to knowledge about the pathogenesis of infect......Streptococcus gordonii ATCC 10558T was isolated from a patient with infective endocarditis in 1946 and announced as a type strain in 1989. Here, we report the 2,154,510-bp draft genome sequence of S. gordonii ATCC 10558T. This sequence will contribute to knowledge about the pathogenesis...

  5. Molecular Epidemiology and Genomics of Group A Streptococcus

    Science.gov (United States)

    Bessen, Debra E.; McShan, W. Michael; Nguyen, Scott V.; Shetty, Amol; Agrawal, Sonia; Tettelin, Hervé

    2014-01-01

    Streptococcus pyogenes (group A streptococcus; GAS) is a strict human pathogen with a very high prevalence worldwide. This review highlights the genetic organization of the species and the important ecological considerations that impact its evolution. Recent advances are presented on the topics of molecular epidemiology, population biology, molecular basis for genetic change, genome structure and genetic flux, phylogenomics and closely related streptococcal species, and the long- and short-term evolution of GAS. The application of whole genome sequence data to addressing key biological questions is discussed. PMID:25460818

  6. Species identification of Streptococcus bovis group isolates causing bacteremia

    DEFF Research Database (Denmark)

    Agergaard, Charlotte N; Knudsen, Elisa; Dargis, Rimtas

    2017-01-01

    This study compared two MALDI-TOF MS systems (Biotyper and VITEK MS) on clinical Streptococcus bovis group isolates (n=66). The VITEK MS gave fewer misidentifications and a higher rate of correct identifications than the Biotyper. Only the identification of S. lutetiensis by the VITEK MS was reli......This study compared two MALDI-TOF MS systems (Biotyper and VITEK MS) on clinical Streptococcus bovis group isolates (n=66). The VITEK MS gave fewer misidentifications and a higher rate of correct identifications than the Biotyper. Only the identification of S. lutetiensis by the VITEK MS...

  7. Genetic differentiation across the Western Pacific populations of the hydrothermal vent bivalve Bathymodiolus spp. and the Eastern Pacific (13°N) population of Bathymodiolus thermophilus

    Science.gov (United States)

    Moraga, Dario; Jollivet, Didier; Denis, Françoise

    1994-10-01

    Deep-sea mussels, closely related to the Bathymodiolus genus and individuals of Bathymodiolus thermophilus, were collected on hydrothermal vents of the Lau and North-Fiji back-arc basins (Western Pacific) and at 13°N on the East Pacific Rise, respectively. Separate tissue homogenates were submitted to starch gel electrophoresis in order to study the genetic structure of the populations at 11 enzyme loci. Significant departures from the Hardy-Weinberg equilibrium were found at Aat-1, Gpi and Pgm loci without any location specificity. All the observed departures corresponded to heterozygote deficiencies that are common in mollusc bivalves. The genetic variability of these mussels was low in all samples, especially for the North-Fiji population. The genetic distances measured between populations demonstrated that significant genetic differentiation occurs between the Western Pacific mussel populations and the Eastern Pacific B. thermophilus, whereas gene flow appeared to be maintained between the two back-arc basins. The presence of both shared heterozygotes and genetic distances found between the western and the eastern populations do not allow us to separate these allopatric forms as distinct sibling species.

  8. Different effects of MglA and MglB on pilus-mediated functions and natural competence in Thermus thermophilus.

    Science.gov (United States)

    Salzer, Ralf; Joos, Friederike; Averhoff, Beate

    2015-03-01

    The thermophilic bacterium Thermus thermophilus is known for its high natural competence. Uptake of DNA is mediated by a DNA translocator that shares components with type IV pili. Localization and function of type IV pili in other bacteria depend on the cellular localization at the poles of the bacterium, a process that involves MglA and MglB. T. thermophilus contains homologs of MglA and MglB. The genes encoding MglA and MglB were deleted and the physiology of the mutants was studied. Deletion of the genes individually or in tandem had no effect on pili formation but pili lost their localization at the poles. The mutants abolished pilus-mediated functions such as twitching motility and adherence but had no effect on uptake of DNA by natural competence. These data demonstrate that MglA and MglB are dispensable for natural transformation and are consistent with the hypothesis that uptake of DNA does not depend on type IV pili or their cellular localization.

  9. Structural Rearrangements in the Active Site of the Thermus thermophilus 16S rRNA Methyltransferase KsgA in a Binary Complex with 5'-Methylthioadenosine

    Energy Technology Data Exchange (ETDEWEB)

    Demirci, H.; Belardinelli, R; Seri, E; Gregory, S; Gualerzi, C; Dahlberg, A; Jogl, G

    2009-01-01

    Posttranscriptional modification of ribosomal RNA (rRNA) occurs in all kingdoms of life. The S-adenosyl-l-methionine-dependent methyltransferase KsgA introduces the most highly conserved rRNA modification, the dimethylation of A1518 and A1519 of 16S rRNA. Loss of this dimethylation confers resistance to the antibiotic kasugamycin. Here, we report biochemical studies and high-resolution crystal structures of KsgA from Thermus thermophilus. Methylation of 30S ribosomal subunits by T. thermophilus KsgA is more efficient at low concentrations of magnesium ions, suggesting that partially unfolded RNA is the preferred substrate. The overall structure is similar to that of other methyltransferases but contains an additional ?-helix in a novel N-terminal extension. Comparison of the apoenzyme with complex structures with 5?-methylthioadenosine or adenosine bound in the cofactor-binding site reveals novel features when compared with related enzymes. Several mobile loop regions that restrict access to the cofactor-binding site are observed. In addition, the orientation of residues in the substrate-binding site indicates that conformational changes are required for binding two adjacent residues of the substrate rRNA.

  10. Agricultural wastes as substrates for β-glucosidase production by Talaromyces thermophilus: Role of these enzymes in enhancing waste paper saccharification.

    Science.gov (United States)

    Mallek-Fakhfakh, Hanen; Fakhfakh, Jawhar; Masmoudi, Najla; Rezgui, Fatma; Gargouri, Ali; Belghith, Hafedh

    2017-04-21

    In the present study, we investigated a potent extracellular β-glucosidases secreted by the thermophilic fungal strain AX4 of Talaromyces thermophilus, isolated from Tunisian soil samples. This strain was selected referring to the highest thermostability of its β-glucosidases compared to the other fungal isolates. The β-glucosidase production was investigated by submerged fermentation. The optimal temperature and initial pH for maximum β-glucosidase production were 50°C and 7.0, respectively. Several carbon sources were assayed for their effects on β-glucosidase production, significant yields were obtained in media containing lactose 1% (3.0 ± 0.36 U/ml) and wheat bran 2% (4.0 ± 0.4 U/ml). The combination of wheat bran at 2% and lactose at 0.8% as carbon source enhanced β-glucosidase production, which reached 8.5 ± 0.28 U/ml. Furthermore, the β-glucosidase-rich enzymatic juice of T. thermophilus exhibited significant synergism with Trichoderma reesei (Rut C30) cellulases for pretreated waste paper (PWP) hydrolysis. Interestingly, the use of this optimal enzymatic cocktail increased 4.23 fold the glucose yield after saccharification of waste paper. A maximum sugar yield (94%) was reached when using low substrate (2%) and enzyme loading (EC1).

  11. Crystallization and preliminary X-ray diffraction study of recombinant adenine phosphoribosyltransferase from the thermophilic bacterium Thermus thermophilus strain HB27

    Science.gov (United States)

    Sinitsyna, E. V.; Timofeev, V. I.; Tuzova, E. S.; Kostromina, M. A.; Murav'eva, T. I.; Esipov, R. S.; Kuranova, I. P.

    2017-07-01

    Adenine phosphoribosyltransferase (APRT) belongs to the type I phosphoribosyltransferase family and catalyzes the formation of adenosine monophosphate via transfer of the 5-phosphoribosyl group from phosphoribosyl pyrophosphate to the nitrogen atom N9 of the adenine base. Proteins of this family are involved in a salvage pathway of nucleotide synthesis, thus providing purine base utilization and maintaining the optimal level of purine bases in the body. Adenine phosphoribosyltransferase from the extremely thermophilic Thermus thermophilus strain HB27 was produced using a highly efficient E. coli producer strain and was then purified by affinity and gel-filtration chromatography. This enzyme was successfully employed as a catalyst for the cascade biosynthesis of biologically important nucleotides. The screening of crystallization conditions for recombinant APRT from T. thermophilus HB27 was performed in order to determine the enzyme structure by X-ray diffraction. The crystallization conditions, which were found by the vapor-diffusion technique, were then optimized to apply the counter-diffusion technique. The crystals of the enzyme were grown by the capillary counter-diffusion method. The crystals belong to sp. gr. P1211 and have the following unitcell parameters: a = 69.86 Å, b = 82.16 Å, c = 91.39 Å, α = γ = 90°, β = 102.58°. The X-ray diffraction data set suitable for the determination of the APRT structure at 2.6 Å resolution was collected from the crystals at the SPring-8 synchrotron facility (Japan).

  12. Potential role of Thermus thermophilus and T. oshimai in high rates of nitrous oxide (N2O) production in ∼80 °C hot springs in the US Great Basin.

    Science.gov (United States)

    Hedlund, B P; McDonald, A I; Lam, J; Dodsworth, J A; Brown, J R; Hungate, B A

    2011-11-01

    Ambient nitrous oxide (N(2)O) emissions from Great Boiling Spring (GBS) in the US Great Basin depended on temperature, with the highest flux, 67.8 ± 2.6 μmol N(2)O-N m(-2) day(-1) , occurring in the large source pool at 82 °C. This rate of N(2)O production contrasted with negligible production from nearby soils and was similar to rates from soils and sediments impacted with agricultural fertilizers. To investigate the source of N(2)O, a variety of approaches were used to enrich and isolate heterotrophic micro-organisms, and isolates were screened for nitrate reduction ability. Nitrate-respiring isolates were identified by 16S rRNA gene sequencing as Thermus thermophilus (31 isolates) and T. oshimai (three isolates). All isolates reduced nitrate to N(2)O but not to dinitrogen and were unable to grow with N(2)O as a terminal electron acceptor. Representative T. thermophilus and T. oshimai strains contained genes with 96-98% and 93% DNA identity, respectively, to the nitrate reductase catalytic subunit gene (narG) of T. thermophilus HB8. These data implicate T. thermophilus and T. oshimai in high flux of N(2)O in GBS and raise questions about the genetic basis of the incomplete denitrification pathway in these organisms and on the fate of biogenic N(2)O in geothermal environments. © 2011 Blackwell Publishing Ltd.

  13. Capsular Polysaccharide Expression in Commensal Streptococcus Species: Genetic and Antigenic Similarities to Streptococcus pneumoniae

    Directory of Open Access Journals (Sweden)

    Uffe B. Skov Sørensen

    2016-11-01

    Full Text Available Expression of a capsular polysaccharide is considered a hallmark of most invasive species of bacteria, including Streptococcus pneumoniae, in which the capsule is among the principal virulence factors and is the basis for successful vaccines. Consequently, it was previously assumed that capsule production distinguishes S. pneumoniae from closely related commensals of the mitis group streptococci. Based on antigenic and genetic analyses of 187 mitis group streptococci, including 90 recognized serotypes of S. pneumoniae, we demonstrated capsule production by the Wzy/Wzx pathway in 74% of 66 S. mitis strains and in virtually all tested strains of S. oralis (subspecies oralis, dentisani, and tigurinus and S. infantis. Additional analyses of genomes of S. cristatus, S. parasanguinis, S. australis, S. sanguinis, S. gordonii, S. anginosus, S. intermedius, and S. constellatus revealed complete capsular biosynthesis (cps loci in all strains tested. Truncated cps loci were detected in three strains of S. pseudopneumoniae, in 26% of S. mitis strains, and in a single S. oralis strain. The level of sequence identities of cps locus genes confirmed that the structural polymorphism of capsular polysaccharides in S. pneumoniae evolved by import of cps fragments from commensal Streptococcus species, resulting in a mosaic of genes of different origins. The demonstrated antigenic identity of at least eight of the numerous capsular polysaccharide structures expressed by commensal streptococci with recognized serotypes of S. pneumoniae raises concerns about potential misidentifications in addition to important questions concerning the consequences for vaccination and host-parasite relationships both for the commensals and for the pathogen.

  14. Antibiotic susceptibility of periodontal Streptococcus constellatus and Streptococcus intermedius clinical isolates.

    Science.gov (United States)

    Rams, Thomas E; Feik, Diane; Mortensen, Joel E; Degener, John E; van Winkelhoff, Arie J

    2014-12-01

    Streptococcus constellatus and Streptococcus intermedius in subgingival dental plaque biofilms may contribute to forms of periodontitis that resist treatment with conventional mechanical root debridement/surgical procedures and may additionally participate in some extraoral infections. Because systemic antibiotics are often used in these clinical situations, and little is known of the antibiotic susceptibility of subgingival isolates of these two bacterial species, this study determined the in vitro susceptibility to six antibiotics of fresh S. constellatus and S. intermedius clinical isolates from human periodontitis lesions. A total of 33 S. constellatus and 17 S. intermedius subgingival strains, each recovered from separate patients with severe chronic periodontitis (n = 50) before treatment, were subjected to antibiotic gradient strip susceptibility testing with amoxicillin, azithromycin, clindamycin, ciprofloxacin, and doxycycline on blood-supplemented Mueller-Hinton agar and to the inhibitory effects of metronidazole at 16 mg/L in an enriched Brucella blood agar dilution assay. Clinical and Laboratory Standards Institute and European Committee on Antimicrobial Susceptibility Testing interpretative standards were used to assess the results. Clindamycin was the most active antibiotic against S. constellatus (minimum inhibitory concentration at 90% [MIC90] 0.25 mg/L), and amoxicillin was most active against S. intermedius (MIC90 0.125 mg/L). A total of 30% of the S. constellatus and S. intermedius clinical isolates were resistant in vitro to doxycycline, 98% were only intermediate in susceptibility to ciprofloxacin, and 90% were resistant to metronidazole at 16 mg/L. Subgingival S. constellatus and S. intermedius exhibited variable antibiotic susceptibility profiles, potentially complicating empirical selection of periodontitis antibiotic therapy in patients who are species positive.

  15. Streptococcus pneumoniae, mecanismos de resistencia antimicrobiana Streptococcus pneumoniae, mechanisms of antimicrobial resistance

    Directory of Open Access Journals (Sweden)

    Amauri Noda Albelo

    2011-09-01

    Full Text Available El Streptococcus pneumoniae, principal agente causal de la neumonía comunitaria, líder en la etiología de la otitis media y la meningitis, en las últimas 3 décadas ha incrementado, de manera importante, su resistencia a los agentes terapéuticos más utilizados, como los betalactámicos, macrólidos, azálidos y fluroquinolonas. La versatilidad adaptativa del microorganismo le ha permitido crear mecanismos capaces de sobreponerse a cualquiera de estas agresiones terapéuticas con un grado variable de eficacia. Se realiza una revisión de los mecanismos más importantes implicados en la adquisición de resistencia antimicrobiana por S. pneumoniae, y se precisan algunos de los factores de riesgo implicados en infección por S. pneumoniae resistente.The Streptococcus pneumoniae, the main causal agent of community pneumonia, leader in the etiology of the otitis media and the meningitis, during the past three decades has increase in a significant way its resistance to the more used therapeutic agents including the beta-lactamase, macrolides, azalides and fluroquinolones. Adaptive versatility of the microorganism allows it to create mechanisms able to overcome to any of these therapeutical aggressions with a variable degree of effectiveness. Authors made a review of the more important mechanisms involved in acquisition of the antimicrobial resistance by S. pneumoniae and some of risk factors involved in the infection due to resistant S. pneumoniae are specified.

  16. Streptococcus oligofermentans Inhibits Streptococcus mutans in Biofilms at Both Neutral pH and Cariogenic Conditions.

    Science.gov (United States)

    Bao, Xudong; de Soet, Johannes Jacob; Tong, Huichun; Gao, Xuejun; He, Libang; van Loveren, Cor; Deng, Dong Mei

    2015-01-01

    Homeostasis of oral microbiota can be maintained through microbial interactions. Previous studies showed that Streptococcus oligofermentans, a non-mutans streptococci frequently isolated from caries-free subjects, inhibited the cariogenic Streptococcus mutans by the production of hydrogen peroxide (HP). Since pH is a critical factor in caries formation, we aimed to study the influence of pH on the competition between S. oligofermentans and S. mutans in biofilms. To this end, S. mutans and S. oligofermentans were inoculated alone or mixed at 1:1 ratio in buffered biofilm medium in a 96-well active attachment model. The single- and dual-species biofilms were grown under either constantly neutral pH or pH-cycling conditions. The latter includes two cycles of 8 h neutral pH and 16 h pH 5.5, used to mimic cariogenic condition. The 48 h biofilms were analysed for the viable cell counts, lactate and HP production. The last two measurements were carried out after incubating the 48 h biofilms in buffers supplemented with 1% glucose (pH 7.0) for 4 h. The results showed that S. oligofermentans inhibited the growth of S. mutans in dual-species biofilms under both tested pH conditions. The lactic acid production of dual-species biofilms was significantly lower than that of single-species S. mutans biofilms. Moreover, dual-species and single-species S. oligofermentans biofilms grown under pH-cycling conditions (with a 16 h low pH period) produced a significantly higher amount of HP than those grown under constantly neutral pH. In conclusion, S. oligofermentans inhibited S. mutans in biofilms not only under neutral pH, but also under pH-cycling conditions, likely through HP production. S. oligofermentans may be a compelling probiotic candidate against caries.

  17. Inhibition of Streptococcus mutans Biofilm Formation by Streptococcus salivarius FruA▿

    Science.gov (United States)

    Ogawa, Ayako; Furukawa, Soichi; Fujita, Shuhei; Mitobe, Jiro; Kawarai, Taketo; Narisawa, Naoki; Sekizuka, Tsuyoshi; Kuroda, Makoto; Ochiai, Kuniyasu; Ogihara, Hirokazu; Kosono, Saori; Yoneda, Saori; Watanabe, Haruo; Morinaga, Yasushi; Uematsu, Hiroshi; Senpuku, Hidenobu

    2011-01-01

    The oral microbial flora consists of many beneficial species of bacteria that are associated with a healthy condition and control the progression of oral disease. Cooperative interactions between oral streptococci and the pathogens play important roles in the development of dental biofilms in the oral cavity. To determine the roles of oral streptococci in multispecies biofilm development and the effects of the streptococci in biofilm formation, the active substances inhibiting Streptococcus mutans biofilm formation were purified from Streptococcus salivarius ATCC 9759 and HT9R culture supernatants using ion exchange and gel filtration chromatography. Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry analysis was performed, and the results were compared to databases. The S. salivarius HT9R genome sequence was determined and used to indentify candidate proteins for inhibition. The candidates inhibiting biofilms were identified as S. salivarius fructosyltransferase (FTF) and exo-beta-d-fructosidase (FruA). The activity of the inhibitors was elevated in the presence of sucrose, and the inhibitory effects were dependent on the sucrose concentration in the biofilm formation assay medium. Purified and commercial FruA from Aspergillus niger (31.6% identity and 59.6% similarity to the amino acid sequence of FruA from S. salivarius HT9R) completely inhibited S. mutans GS-5 biofilm formation on saliva-coated polystyrene and hydroxyapatite surfaces. Inhibition was induced by decreasing polysaccharide production, which is dependent on sucrose digestion rather than fructan digestion. The data indicate that S. salivarius produces large quantities of FruA and that FruA alone may play an important role in multispecies microbial interactions for sucrose-dependent biofilm formation in the oral cavity. PMID:21239559

  18. In silico analysis of the competition between Streptococcus sanguinis and Streptococcus mutans in the dental biofilm.

    Science.gov (United States)

    Valdebenito, B; Tullume-Vergara, P O; González, W; Kreth, J; Giacaman, R A

    2017-12-13

    During dental caries, the dental biofilm modifies the composition of the hundreds of involved bacterial species. Changing environmental conditions influence competition. A pertinent model to exemplify the complex interplay of the microorganisms in the human dental biofilm is the competition between Streptococcus sanguinis and Streptococcus mutans. It has been reported that children and adults harbor greater numbers of S. sanguinis in the oral cavity, associated with caries-free teeth. Conversely, S. mutans is predominant in individuals with a high number of carious lesions. Competition between both microorganisms stems from the production of H2 O2 by S. sanguinis and mutacins, a type of bacteriocins, by S. mutans. There is limited evidence on how S. sanguinis survives its own H2 O2 levels, or if it has other mechanisms that might aid in the competition against S. mutans, nonetheless. We performed a genomic and metabolic pathway comparison, coupled with a comprehensive literature review, to better understand the competition between these two species. Results indicated that S. sanguinis can outcompete S. mutans by the production of an enzyme capable of metabolizing H2 O2 . S. mutans, however, lacks the enzyme and is susceptible to the peroxide from S. sanguinis. In addition, S. sanguinis can generate energy through gluconeogenesis and seems to have evolved different communication mechanisms, indicating that novel proteins may be responsible for intra-species communication. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. The novel species Streptococcus tigurinus and its association with oral infection.

    Science.gov (United States)

    Zbinden, Andrea; Bostanci, Nagihan; Belibasakis, Georgios N

    2015-01-01

    Streptococcus tigurinus is a novel species of viridans streptococci, shown to cause severe invasive infections such as infective endocarditis, spondylodiscitis and meningitis. S. tigurinus belongs to the Streptococcus mitis group and is most closely related to Streptococcus mitis, Streptococcus oralis, Streptococcus pneumoniae, Streptococcus pseudopneumoniae and Streptococcus infantis. The presence of S. tigurinus in the human oral cavity has been documented, including in patients with periodontal disease. This review addresses the available scientific knowledge on S. tigurinus and its association with closely related streptococci, and discusses its putative involvement in common oral infections. While there is as yet no strong evidence on the involvement of S. tigurinus with oral infections, its presence in the oral cavity and its association with endocarditis warrants special attention for a link between oral and systemic infection.

  20. Fluoroquinolone-resistant Streptococcus agalactiae: epidemiology and mechanism of resistance.

    Science.gov (United States)

    Wehbeh, Wehbeh; Rojas-Diaz, Roberto; Li, Xinying; Mariano, Noriel; Grenner, Louise; Segal-Maurer, Sorana; Tommasulo, Barbara; Drlica, Karl; Urban, Carl; Rahal, James J

    2005-06-01

    Quinolone-resistant Streptococcus agalactiae bacteria were recovered from single-patient isolates and found to contain mutations in the gyrase and topoisomerase IV genes. Pulsed-field gel electrophoresis demonstrated that four isolates from the same long-term care facility were closely related; in seven cases, quinolone-resistant Haemophilus influenzae and S. agalactiae bacteria were isolated from the same patient.

  1. Fluoroquinolone-Resistant Streptococcus agalactiae: Epidemiology and Mechanism of Resistance

    OpenAIRE

    Wehbeh, Wehbeh; Rojas-Diaz, Roberto; Li, Xinying; Mariano, Noriel; Grenner, Louise; Segal-Maurer, Sorana; Tommasulo, Barbara; Drlica, Karl; Urban, Carl; Rahal, James J.

    2005-01-01

    Quinolone-resistant Streptococcus agalactiae bacteria were recovered from single-patient isolates and found to contain mutations in the gyrase and topoisomerase IV genes. Pulsed-field gel electrophoresis demonstrated that four isolates from the same long-term care facility were closely related; in seven cases, quinolone-resistant Haemophilus influenzae and S. agalactiae bacteria were isolated from the same patient.

  2. Detection of Streptococcus iniae and Lactococcus garvieae by ...

    African Journals Online (AJOL)

    Streptococcosis is one of the most important bacterial diseases in farmed salmonid fishes. Streptococcus iniae and Lactococcus garvieae are known as the major pathogens of streptococcosis and lactococcosis in the rainbow trout, Oncorhynchus mykiss. The present study accomplished the detection of the two mentioned ...

  3. Antibiotic resistant profile of Streptococcus pneumoniae from the ...

    African Journals Online (AJOL)

    Background: Antimicrobial resistance in Streptococcus pneumoniae has compromised the effectiveness of therapy for pneumococcal diseases and asymptomatic nasopharyngeal carriers play an important role in transmission of resistant strains. Method: Eighty-eight volunteer students attending 2 secondary schools in Jos, ...

  4. A Visual Review of the Human Pathogen Streptococcus pneumoniae

    DEFF Research Database (Denmark)

    Engholm, Ditte Høyer; Kilian, Mogens; Goodsell, David

    2017-01-01

    Being the principal causative agent of bacterial pneumonia, otitis media, meningitis and septicemia, the bacterium Streptococcus pneumoniae is a major global health problem. To highlight the molecular basis of this problem, we have portrayed essential biological processes of the pneumococcal life...

  5. Thalamic abscess caused by a rare pathogen: streptococcus ...

    African Journals Online (AJOL)

    Streptococcus constellatus is a microorganism that lives commensally in the oropharyngeal region, urogenital region, and intestinal tract. However, it can cause infection in patients with certain predisposing factors. Rarely, this microorganism can cause a brain abscess. Thalamic localization of brain abscesses is much rarer ...

  6. Streptococcus milleri causing infection in man | Millar | South African ...

    African Journals Online (AJOL)

    We describe the microbiological and morphological characteristics of 151 strains of Streptococcus milleri isolated during the course of routine bacteriological investigations. Although these strains formed a fairly heterogeneous group, several constant features were identified which typify the species. Strept. milleri emerged ...

  7. Rate of isolation of streptococcus species from children with ...

    African Journals Online (AJOL)

    Background: Streptococcus species are among the commonest bacterial causes of childhood morbidity in developing countries. Streptococcal diseases in children have not been as well characterized in Nigeria as it has been in industrialized countries. The rudimentary nature of public health surveillance makes the true ...

  8. Cations and oxidative stress response in Streptococcus pneumoniae

    NARCIS (Netherlands)

    Farshchi Andisi, Vahid

    2013-01-01

    Streptococcus pneumoniae is a bacterium, which colonizes the human nasopharynx and can cause serious disease, such as pneumonia, otitis media, meningitis, and bacteremia. Generally, groups at risk for invasive pneumococcal disease are young children, elderly and immuno-compromised patients, both in

  9. Diversity of Streptococcus mutans strains in bacterial interspecies interactions

    NARCIS (Netherlands)

    Li, X.; Hoogenkamp, M.A.; Ling, J.; Crielaard, W.; Deng, D.M.

    2014-01-01

    Biofilms are matrix-enclosed microbial population adhere to each other and to surfaces. Compared to planktonic bacterial cells, biofilm cells show much higher levels of antimicrobial resistance. We aimed to investigate Streptococcus mutans strain diversity in biofilm formation and chlorhexidine

  10. Escherichia coli, Streptococcus pneumoniae, 4(1.2%)

    African Journals Online (AJOL)

    INTRODUCTION. Bacterial conjunctivitis is common and affects all age groups. They are mainly caused by bacteria such as. Streptococcus pneumoniae, Haemophilus influenzae , Staphylo- coccus aureus and Neisseria gonorrhoeae in the normal host. In the new born, who often get this infection from the vaginal fluids of ...

  11. Effect of 10% sodium ascorbate on Streptococcus mutans ...

    African Journals Online (AJOL)

    Sodium ascorbate has been suggested to modify bleaching agents' side effects especially on composite resin bonding to dental hard tissues. The aim of the present study was to evaluate the effect of 10% sodium ascorbate on Streptococcus mutans adherence to bleached enamel surfaces. Sixty enamel slabs from bovine ...

  12. Maternal vaginorectal colonization by Group B Streptococcus and ...

    African Journals Online (AJOL)

    Background: Group B streptococcus (GBS) and Listeria monocytogenes are members of the normal microbes of the female genital tract. During labour GBS and Listeria monocytogenes may infect the new-borns, leading to neonatal sepsis and meningitis. So far, there is no report on prevalence of GBS and Listeria ...

  13. Antimicrobial Drug Use and Macrolide-Resistant Streptococcus pyogenes, Belgium

    OpenAIRE

    Van Heirstraeten, Liesbet; Coenen, Samuel; Lammens, Christine; Hens, Niel; Goossens, Herman; Malhotra-Kumar, Surbhi

    2012-01-01

    In Belgium, decreasing macrolide, lincosamide, streptogramins B, and tetracycline use during 1997–2007 correlated significantly with decreasing macrolide-resistant Streptococcus pyogenes during 1999–2009. Maintaining drug use below a critical threshold corresponded with low-level macrolide-resistant S. pyogenes and an increased number of erm(A)-harboring emm77 S. pyogenes with low fitness costs.

  14. Lysozyme Resistance in Streptococcus suis Is Highly Variable and Multifactorial

    NARCIS (Netherlands)

    Wichgers, P.J.; Weeghel, van C.; Rebel, J.M.J.; Smits, M.A.; Putten, van J.P.M.; Smith, H.E.

    2012-01-01

    Background Streptococcus suis is an important infectious agent for pigs and occasionally for humans. The host innate immune system plays a key role in preventing and eliminating S. suis infections. One important constituent of the innate immune system is the protein lysozyme, which is present in a

  15. Anti-Streptococcus pyogenes Activity of Selected Medicinal Plant ...

    African Journals Online (AJOL)

    Trop J Pharm Res, August 2013;12 (4): 538. Table 1 (contd.): Antibacterial activity of selected Thai medicinal plants against Streptococcus pyogenes NPRC 101. Botanical species. Family. Voucher no. Plant part. Extract yield (%). Inhibiti on zonea. (mm). MIC/MBC. (µg/ml). Rhodomyrtus tomentosa (Aiton) Hassk. Myrtaceae.

  16. Molecular epidemiology and population structure of bovine Streptococcus uberis

    DEFF Research Database (Denmark)

    Rato, M G; Bexiga, R; Nunes, S F

    2008-01-01

    The molecular epidemiology and population structure of 30 bovine subclinical mastitis field isolates of Streptococcus uberis, collected from 6 Portuguese herds (among 12 farms screened) during 2002 and 2003, were examined by using pulsed-field gel electrophoresis (PFGE) for clustering of the isol...

  17. Bacteriuria with group B streptococcus and preterm birth

    DEFF Research Database (Denmark)

    Khalil, M. R.; Uldbjerg, N.; Thorsen, P.

    2015-01-01

    Objectives: Preterm delivery (PTD) contributes to 70% of all perinatal deaths and nearly 50% of permanent neurological damages in children. Treatment and follow-up to prevent recolonization in pregnant women with Group B Streptococcus (GBS) in the urine may reduce the frequency of PTD...

  18. Outbreak of Streptococcus pneumoniae in a Psychiatric Unit

    Centers for Disease Control (CDC) Podcasts

    2012-11-02

    Dr. Katherine Fleming-Dutra, an epidemiologist at CDC, discusses her investigation of a Streptococcus pneumoniae outbreak in a pediatric psychiatric unit.  Created: 11/2/2012 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID); National Center for Immunization and Respiratory Diseases (NCIRD).   Date Released: 11/5/2012.

  19. Erythromycin-nonsusceptible Streptococcus pneumoniae in Children, 1999–2001

    OpenAIRE

    McEllistrem, M. Catherine; Adams, Jennifer M.; Shutt, Kathleen; Sanza, Laurie T.; Facklam, Richard R.; Whitney, Cynthia G.; Jorgensen, James H.; Harrison, Lee H.

    2005-01-01

    After increasing from 1995 to 1999, invasive erythromycin-nonsusceptible Streptococcus pneumoniae rates per 100,000 decreased 53.6% in children from Baltimore, Maryland (US), from 1999 to 2001, which was partially attributed to strains related to the mefE-carrying England14-9 clone. The decline in infection rates was likely due to the pneumococcal 7-valent conjugate vaccine.

  20. Host-pathogen interaction during Streptococcus pneumoniae colonization and infection

    NARCIS (Netherlands)

    D. Bogaert (Debby)

    2004-01-01

    markdownabstract__Abstract__ Streptococcus pneumoniae was discovered by Sternberg and Pasteur in 1880. It took another six years to discover that this microorganism, called the pneumococcus, was the actual cause of bacterial pneumonia . Subsequently, this bacterium has been shown to provoke an