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Sample records for gram-positive spore-forming bacterium

  1. Spore-Forming Bacteria that Resist Sterilization

    Science.gov (United States)

    LaDuc, Myron; Venkateswaran, Kasthuri

    2003-01-01

    A report presents a phenotypic and genotypic characterization of a bacterial species that has been found to be of the genus Bacillus and has been tentatively named B. odysseensis because it was isolated from surfaces of the Mars Odyssey spacecraft as part of continuing research on techniques for sterilizing spacecraft to prevent contamination of remote planets by terrestrial species. B. odysseensis is a Gram-positive, facultatively anaerobic, rod-shaped bacterium that forms round spores. The exosporium has been conjectured to play a role in the elevated resistance to sterilization. Research on the exosporium is proposed as a path toward improved means of sterilization, medical treatment, and prevention of biofouling.

  2. Jeotgalibacillus soli sp. nov., a Gram-stain-positive bacterium isolated from soil.

    Science.gov (United States)

    Cunha, Sofia; Tiago, Igor; Paiva, Gabriel; Nobre, Fernanda; da Costa, Milton S; Veríssimo, António

    2012-03-01

    A Gram-staining-positive, motile, rod-shaped, spore-forming bacterium, designated P9(T), was isolated from soil in Portugal. This organism was aerobic and catalase- and oxidase-positive. It had an optimum growth temperature of about 35 °C and an optimum growth pH of about 8.0-8.5, and grew in medium with 0-9% (w/v) NaCl. The cell-wall peptidoglycan was of the A1α type, with L-lysine as the diagnostic diamino acid. The major respiratory quinone was menaquinone 7 (MK-7) and the major fatty acids were anteiso-C(15:0) (45.4%), iso-C(15:0) (22.0%) and anteiso-C(17:0) (11.2%). The genomic DNA G+C content was about 39.4 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain P9(T) was most closely related to Jeotgalibacillus campisalis DSM 18983(T) (96.8%) and Jeotgalibacillus marinus DSM 1297(T) (96.5%). These two recognized species formed a coherent cluster with strain P9(T) that was supported by a bootstrap value of 99%. On the basis of the phylogenetic analysis and physiological and biochemical characteristics, strain P9(T) (=DSM 23228(T)=LMG 25523(T)) represents a novel species of the genus Jeotgalibacillus, for which the name Jeotgalibacillus soli sp. nov. is proposed.

  3. A pathway closely related to the (D)-tagatose pathway of gram-negative enterobacteria identified in the gram-positive bacterium Bacillus licheniformis.

    Science.gov (United States)

    Van der Heiden, Edwige; Delmarcelle, Michaël; Lebrun, Sarah; Freichels, Régine; Brans, Alain; Vastenavond, Christian M; Galleni, Moreno; Joris, Bernard

    2013-06-01

    We report the first identification of a gene cluster involved in d-tagatose catabolism in Bacillus licheniformis. The pathway is closely related to the d-tagatose pathway of the Gram-negative bacterium Klebsiella oxytoca, in contrast to the d-tagatose 6-phosphate pathway described in the Gram-positive bacterium Staphylococcus aureus.

  4. A Pathway Closely Related to the d-Tagatose Pathway of Gram-Negative Enterobacteria Identified in the Gram-Positive Bacterium Bacillus licheniformis

    OpenAIRE

    Van der Heiden, Edwige; Delmarcelle, Michaël; Lebrun, Sarah; Freichels, Régine; Brans, Alain; Vastenavond, Christian M.; Galleni, Moreno; Joris, Bernard

    2013-01-01

    We report the first identification of a gene cluster involved in d-tagatose catabolism in Bacillus licheniformis. The pathway is closely related to the d-tagatose pathway of the Gram-negative bacterium Klebsiella oxytoca, in contrast to the d-tagatose 6-phosphate pathway described in the Gram-positive bacterium Staphylococcus aureus.

  5. A Pathway Closely Related to the d-Tagatose Pathway of Gram-Negative Enterobacteria Identified in the Gram-Positive Bacterium Bacillus licheniformis

    Science.gov (United States)

    Van der Heiden, Edwige; Lebrun, Sarah; Freichels, Régine; Brans, Alain; Vastenavond, Christian M.; Galleni, Moreno; Joris, Bernard

    2013-01-01

    We report the first identification of a gene cluster involved in d-tagatose catabolism in Bacillus licheniformis. The pathway is closely related to the d-tagatose pathway of the Gram-negative bacterium Klebsiella oxytoca, in contrast to the d-tagatose 6-phosphate pathway described in the Gram-positive bacterium Staphylococcus aureus. PMID:23524682

  6. Microbiological method for radiation sterilization (III). Development of identification software of spore-forming bacteria by using BBL CRYSTAL GP identification kit

    International Nuclear Information System (INIS)

    Hironiwa, Takayuki; Yamamoto, Yoko; Koshikawa, Tomihiko

    2004-01-01

    The part III in this title series describes the development of software for identification of spore-forming bacteria using the commercially available BBL CRYSTAL GP Identification Kit (Becton, Dickinson and Co., Ltd.), which is essentially for identification of Gram positive bacteria and is not always suitable for the spore-former in the radiation sterilization of medical devices. Isolation and identification of a spore-forming bacterium have to be confirmed by phase-contrast microscopy. The bacteria cultured overnight are to be inoculated in the Kit and cultured for 18-24 hr at 35-37 deg C with the lid attached by substrates for identification. Here, 30 substrates and probability of positive reactions to the substrates have been tested for spore-formers to make the computer software for final identification. The system is possible to identify 13 spp. of Bacillus, 4 of Paenibacillus, 2 of Brevibaccilus and 1 of Virgibacillus, which are the usual bioburden. For possible misidentification, re-isolation of the bacterium, prolonged culture, concentrated inoculation and re-consideration for ranking of identification the software provides are necessary as well as other identification approaches. Thus, as described in this series, the radio-resistance of, and radiation dose for, the bioburden can be evaluated more easily than hitherto, with use of the kits in radiation sterilization. (N.I.)

  7. Salirhabdus euzebyi gen. nov., sp. nov., a Gram-positive, halotolerant bacterium isolated from a sea salt evaporation pond.

    Science.gov (United States)

    Albuquerque, Luciana; Tiago, Igor; Rainey, Fred A; Taborda, Marco; Nobre, M Fernanda; Veríssimo, António; da Costa, Milton S

    2007-07-01

    A low-G+C, Gram-positive bacterium, designated CVS-14(T), was recovered from a sea salt evaporation pond on the island of Sal in the Cape Verde Archipelago. This organism was catalase- and oxidase-positive. Cells were motile, spore-forming aerobic rods, with an optimum growth temperature of about 35-40 degrees C and optimum pH between 7.0 and 8.5. Optimal growth occurred in media containing 4-6 % (w/v) NaCl, although the organism was able to grow in medium without added NaCl and in medium containing 16 % NaCl. The cell-wall peptidoglycan was of A1 gamma type and the major respiratory quinone was menaquinone 7 (MK-7). Major fatty acids were iso-15 : 0, anteiso-15 : 0, iso-17 : 0 and anteiso-17 : 0. The DNA G+C content was 37.0 mol%. Phylogenetic analysis of the 16S rRNA gene sequence indicated that strain CVS-14(T) formed a distinct new branch within the radiation of the moderately halophilic bacilli group, forming a separate lineage from species of the genera Salinibacillus, Paucisalibacillus, Oceanobacillus, Lentibacillus and Virgibacillus. Strain CVS-14(T) showed 16S rRNA gene pairwise similarity values of approximately 95 % with species of the genus Salinibacillus. On the basis of morphological, physiological, chemotaxonomic and phylogenetic characteristics, strain CVS-14(T) is considered to represent a novel species in a new genus, for which the name Salirhabdus euzebyi gen. nov., sp. nov. is proposed. The type strain is CVS-14(T) (=LMG 22839(T)=CIP 108577(T)).

  8. Expression of a Clostridium perfringens genome-encoded putative N-acetylmuramoyl-L-alanine amidase as a potential antimicrobial to control the bacterium

    Science.gov (United States)

    Clostridium perfringens is a Gram-positive, spore-forming anaerobic bacterium that plays a substantial role in non-foodborne human, animal and avian diseases as well as human foodborne disease. Previously discovered C. perfringens bacteriophage lytic enzyme amino acid sequences were utilized to iden...

  9. Structure, diversity and evolution of protein toxins from spore-forming entomopathogenic bacteria

    NARCIS (Netherlands)

    Maagd, de R.A.; Bravo, A.; Berry, C.; Crickmore, N.; Schnepf, H.E.

    2003-01-01

    Gram-positive spore-forming entomopathogenic bacteria can utilize a large variety of protein toxins to help them invade, infect, and finally kill their hosts, through their action on the insect midgut. These toxins belong to a number of homology groups containing a diversity of protein structures

  10. Desulfotomaculum arcticum sp. nov., a novel spore-forming, moderately thermophilic, sulfate-reducing bacterium isolated from a permanently cold fjord sediment of Svalbard

    DEFF Research Database (Denmark)

    Vandieken, Verona; Knoblauch, Christian; Jørgensen, Bo Barker

    2006-01-01

    Strain 15T is a novel spore-forming, sulfate-reducing bacterium isolated from a permanently cold fjord sediment of Svalbard. Sulfate could be replaced by sulfite or thiosulfate. Hydrogen, formate, lactate, propionate, butyrate, hexanoate, methanol, ethanol, propanol, butanol, pyruvate, malate...

  11. LEVELS AND TYPES OF AEROBIC SPORE FORMING BACTERIA ...

    African Journals Online (AJOL)

    The four companies whose packaged product were studied had an average plate total spore counts as follows: Company A=6.2x 103; Company B= 3.1x 104; Company C= 6.0x 104 and Company D= 3.1x102 colony forming units per gram, respectively. Identification tests showed that among the aerobic spore formers were ...

  12. Isolation and characterization of Caldicellulosiruptor lactoaceticus sp. nov., an extremely thermophilic, cellulolytic, anaerobic bacterium

    DEFF Research Database (Denmark)

    Mladenovska, Zuzana; Mathrani, Indra M.; Ahring, Birgitte Kiær

    1995-01-01

    An anaerobic, extremely thermophilic, cellulolytic, non-spore-forming bacterium, strain 6A, was isolated from an alkaline hot spring in Hverageroi, Iceland. The bacterium was non-motile, rod-shaped (1.5-3.5 x 0.7 mu m) and occurred singly, in pairs or in chains and stained gram-negative. The growth...

  13. Methods for targetted mutagenesis in gram-positive bacteria

    Science.gov (United States)

    Yang, Yunfeng

    2014-05-27

    The present invention provides a method of targeted mutagenesis in Gram-positive bacteria. In particular, the present invention provides a method that effectively integrates a suicide integrative vector into a target gene in the chromosome of a Gram-positive bacterium, resulting in inactivation of the target gene.

  14. ["Candidatus contubernalis alkalaceticum," an obligately syntrophic alkaliphilic bacterium capable of anaerobic acetate oxidation in a coculture with Desulfonatronum cooperativum].

    Science.gov (United States)

    Zhilina, T N; Zavarzina, D G; Kolganova, T V; Turova, T P; Zavarzin, G A

    2005-01-01

    From the silty sediments of the Khadyn soda lake (Tuva), a binary sulfidogenic bacterial association capable of syntrophic acetate oxidation at pH 10.0 was isolated. An obligately syntrophic, gram-positive, spore-forming alkaliphilic rod-shaped bacterium performs acetate oxidation in a syntrophic association with a hydrogenotrophic, alkaliphilic sulfate-reducing bacterium; the latter organism was previously isolated and characterized as the new species Desulfonatronum cooperativum. Other sulfate-reducing bacteria of the genera Desulfonatronum and Desulfonatronovibrio can also act as the hydrogenotrophic partner. Apart from acetate, the syntrophic culture can oxidize ethanol, propanol, isopropanol, serine, fructose, and isobutyric acid. Selective amplification of 16S rRNA gene fragments of the acetate-utilizing syntrophic component of the binary culture was performed; it was found to cluster with clones of uncultured gram-positive bacteria within the family Syntrophomonadaceae. The acetate-oxidizing bacterium is thus the first representative of this cluster obtained in a laboratory culture. Based on its phylogenetic position, the new acetate-oxidizing syntrophic bacterium is proposed to be assigned, in a Candidate status, to a new genus and species: "Candidatus Contubernalis alkalaceticum."

  15. Amino acids in cell wall of Gram-positive bacterium Micrococcus sp. hsn08 with flocculation activity on Chlorella vulgaris biomass.

    Science.gov (United States)

    Li, Yi; Xu, Yanting; Zheng, Tianling; Wang, Hailei

    2018-02-01

    The aim of this work was to investigate the flocculation mechanism by Gram-positive bacterium, Micrococcus sp. hsn08 as a means for harvesting Chlorella vulgaris biomass. Bacterial cells of Micrococcus sp. hsn08 were added into algal culture to harvest algal cells through direct contacting with algae to form flocs. Viability dependence test confirmed that flocculation activity does not depend on live bacteria, but on part of the peptidoglycan. The further investigation has determined that amino acids in cell wall play an important role to flocculate algal cells. Positively charged calcium can combine bacterial and algal cells together, and form a bridge between them, thereby forming the flocs, suggesting that ions bridging is the main flocculation mechanism. These results suggest that bacterial cells of Micrococcus sp. hsn08 can be applied to harvest microalgae biomass with the help of amino acids in cell wall. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. A Clostridium difficile-Specific, Gel-Forming Protein Required for Optimal Spore Germination

    Directory of Open Access Journals (Sweden)

    M. Lauren Donnelly

    2017-01-01

    Full Text Available Clostridium difficile is a Gram-positive spore-forming obligate anaerobe that is a leading cause of antibiotic-associated diarrhea worldwide. In order for C. difficile to initiate infection, its aerotolerant spore form must germinate in the gut of mammalian hosts. While almost all spore-forming organisms use transmembrane germinant receptors to trigger germination, C. difficile uses the pseudoprotease CspC to sense bile salt germinants. CspC activates the related subtilisin-like protease CspB, which then proteolytically activates the cortex hydrolase SleC. Activated SleC degrades the protective spore cortex layer, a step that is essential for germination to proceed. Since CspC incorporation into spores also depends on CspA, a related pseudoprotease domain, Csp family proteins play a critical role in germination. However, how Csps are incorporated into spores remains unknown. In this study, we demonstrate that incorporation of the CspC, CspB, and CspA germination regulators into spores depends on CD0311 (renamed GerG, a previously uncharacterized hypothetical protein. The reduced levels of Csps in gerG spores correlate with reduced responsiveness to bile salt germinants and increased germination heterogeneity in single-spore germination assays. Interestingly, asparagine-rich repeat sequences in GerG’s central region facilitate spontaneous gel formation in vitro even though they are dispensable for GerG-mediated control of germination. Since GerG is found exclusively in C. difficile, our results suggest that exploiting GerG function could represent a promising avenue for developing C. difficile-specific anti-infective therapies.

  17. Probing interaction of Gram-positive and Gram-negative bacterial cells with ZnO nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Aanchal; Bhargava, Richa; Poddar, Pankaj, E-mail: p.poddar@ncl.res.in

    2013-04-01

    In the present work, the physiological effects of the ZnO nanorods on the Gram positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli and Aerobacter aerogenes) bacterial cells have been studied. The analysis of bacterial growth curves for various concentrations of ZnO nanorods indicates that Gram positive and Gram negative bacterial cells show inhibition at concentrations of ∼ 64 and ∼ 256 μg/mL respectively. The marked difference in susceptibility towards nanorods was also validated by spread plate and disk diffusion methods. In addition, the scanning electron micrographs show a clear damage to the cells via changed morphology of the cells from rod to coccoid etc. The confocal optical microscopy images of these cells also demonstrate the reduction in live cell count in the presence of ZnO nanorods. These, results clearly indicate that the antibacterial activity of ZnO nanorods is higher towards Gram positive bacterium than Gram negative bacterium which indicates that the structure of the cell wall might play a major role in the interaction with nanostructured materials and shows high sensitivity to the particle concentration. Highlights: ► Effect of ZnO nanorods on the growth cycles of four bacterial strains. ► A relation has been established between growth rate of bacteria and concentration. ► Serious damage in the morphology of bacterial cells in the presence of ZnO nanorods. ► Microscopic studies to see the time dependent effect on bacterial cells.

  18. Intestinimonas butyriciproducens gen. nov., sp. nov., a novel butyrate-producing bacterium from the mouse intestine

    NARCIS (Netherlands)

    Kläring, K.; Hanske, L.; Bui, T.P.N.; Charrier, C.; Blaut, M.; Haller, D.; Plugge, C.M.; Clavel, T.

    2013-01-01

    Whilst creating a bacterial collection of strains from the mouse intestine, we isolated a Gram-negative, spore-forming, non-motile and strictly anaerobic rod-shaped bacterium from the caecal content of a TNFdeltaARE mouse. The isolate, referred to as strain SRB-521-5-IT, was originally cultured on a

  19. Thermotoga lettingae sp. nov. : a novel thermophilic, methanol-degrading bacterium isolated from a thermophilic anaerobic reactor

    NARCIS (Netherlands)

    Balk, M.; Weijma, J.; Stams, A.J.M.

    2002-01-01

    A novel, anaerobic, non-spore-forming, mobile, Gram-negative, thermophilic bacterium, strain TMO(T), was isolated from a thermophilic sulfate-reducing bioreactor operated at 65 degrees C with methanol as the sole substrate. The G C content of the DNA of strain TMO(T) was 39.2 molÐThe optimum pH,

  20. Formation and characterization of non-growth states in Clostridium thermocellum: spores and L-forms

    Directory of Open Access Journals (Sweden)

    Mearls Elizabeth B

    2012-08-01

    Full Text Available Abstract Background Clostridium thermocellum is an anaerobic thermophilic bacterium that exhibits high levels of cellulose solublization and produces ethanol as an end product of its metabolism. Using cellulosic biomass as a feedstock for fuel production is an attractive prospect, however, growth arrest can negatively impact ethanol production by fermentative microorganisms such as C. thermocellum. Understanding conditions that lead to non-growth states in C. thermocellum can positively influence process design and culturing conditions in order to optimize ethanol production in an industrial setting. Results We report here that Clostridium thermocellum ATCC 27405 enters non-growth states in response to specific growth conditions. Non-growth states include the formation of spores and a L-form-like state in which the cells cease to grow or produce the normal end products of metabolism. Unlike other sporulating organisms, we did not observe sporulation of C. thermocellum in low carbon or nitrogen environments. However, sporulation did occur in response to transfers between soluble and insoluble substrates, resulting in approximately 7% mature spores. Exposure to oxygen caused a similar sporulation response. Starvation conditions during continuous culture did not result in spore formation, but caused the majority of cells to transition to a L-form state. Both spores and L-forms were determined to be viable. Spores exhibited enhanced survival in response to high temperature and prolonged storage compared to L-forms and vegetative cells. However, L-forms exhibited faster recovery compared to both spores and stationary phase cells when cultured in rich media. Conclusions Both spores and L-forms cease to produce ethanol, but provide other advantages for C. thermocellum including enhanced survival for spores and faster recovery for L-forms. Understanding the conditions that give rise to these two different non-growth states, and the implications that

  1. Thermaerobacter litoralis sp. nov., a strictly aerobic and thermophilic bacterium isolated from a coastal hydrothermal field

    DEFF Research Database (Denmark)

    Tanaka, Reiji; Kawaichi, Satoshi; Nishimura, Hiroshi

    2006-01-01

    A novel thermophilic bacterium, strain KW1T, was isolated from a coastal hydrothermal field on the Satsuma Peninsula, Kagoshima Prefecture, Japan. The variably Gram-stained cells were motile rods with flagella, did not form spores and proliferated at 52-78°C (optimum, 70°C), pH 5-8 (optimum, pH 7...

  2. Microbacter margulisiae gen. nov., sp. nov., a novel propionigenic bacterium isolated from sediments of an acid rock drainage pond

    NARCIS (Netherlands)

    Sanchez Andrea, I.; Luis Sanz, J.; Stams, A.J.M.

    2014-01-01

    A novel anaerobic propionigenic bacterium, strain ADRIT, was isolated from sediment of an acid rock drainage environment (Tinto River, Spain). Cells were small (0.4-0.6 x 1-1.7 µm), non-motile and non-spore forming rods. Cells possessed a Gram-negative cell wall structure and were vancomycin

  3. Gelria glutamica gen. nov., sp. a thermophilic oligately syntrophic glutamate-degrading anaerobe

    NARCIS (Netherlands)

    Plugge, C.M.; Balk, M.; Zoetendal, E.G.; Stams, A.J.M.

    2002-01-01

    A novel anaerobic, Gram-positive, thermophilic, spore-forming, obligately syntrophic, glutamate-degrading bacterium, strain TGO(T), was isolated from a propionate-oxidizing methanogenic enrichment culture. The axenic culture was obtained by growing the bacterium on pyruvate. Cells were rod-shaped

  4. Detection, cloning and bioinformatics analysis of vip1/vip2 genes ...

    African Journals Online (AJOL)

    Bio-insecticides based on the spore forming bacterium, Bacillus thuringiensis (Bt) have been used for commercial scale for the past 40 years. Bt is a Gram-positive soil bacterium that forms insecticidal crystal proteins (ICPs) during sporulation; it has been characterized as an insect pathogen. Vegetative insecticidal protein ...

  5. Evaluation of gram-chromotrope kinyoun staining technique: its effectiveness in detecting microsporidial spores in fecal specimens.

    Science.gov (United States)

    Salleh, Fatmah M; Al-Mekhlafi, Abdulsalam M; Nordin, Anisah; Yasin, 'Azlin M; Al-Mekhlafi, Hesham M; Moktar, Norhayati

    2011-01-01

    This study was conducted to evaluate the modification of the usual Gram-chromotrope staining technique developed in-house known as Gram-chromotrope Kinyoun (GCK) in comparison with the Weber Modified Trichrome (WMT) staining technique; as the reference technique. Two hundred and ninety fecal specimens received by the Microbiology Diagnostic Laboratory of Hospital Universiti Kebangsaan Malaysia were examined for the presence of microsporidial spores. The sensitivity and specificity of GCK compared to the reference technique were 98% and 98.3%, respectively. The positive and negative predictive values were 92.5% and 99.6%, respectively. The agreement between the reference technique and the GCK staining technique was statistically significant by Kappa statistics (K = 0.941, P staining technique has high sensitivity and specificity in the detection of microsporidial spores in fecal specimens. Hence, it is recommended to be used in the diagnosis of intestinal microsporidiosis. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Man and pigs: sharing the same C. difficile

    NARCIS (Netherlands)

    Keessen, E.C.

    2013-01-01

    Clostridium difficile is an anaerobic spore forming gram-positive bacterium. Infection with C. difficile may lead in humans to symptomless carriership, but may also lead to diarrhea varying in severity from mild to life-threatening pseudomembraneous colitis. C. difficile spores can survive for long

  7. Widespread abundance of functional bacterial amyloid in Mycolata and other Gram-positive bacteria

    DEFF Research Database (Denmark)

    Jordal, Peter Bruun; Dueholm, Morten Simonsen; Larsen, Poul

    2009-01-01

    extracellular fibrils were also produced. In three cases, FuBA was only revealed after extensive removal of extracellular material by saponification, indicating an integrated attachment within the cellular envelope. Spores from species within the genera Streptomyces, Bacillus and Nocardia were all coated...... analysis. We conclude that amyloid is widespread among Gram-positive bacteria and may in many species constitute a hitherto overlooked integral part of the spores and the cellular envelope....

  8. c-di-GMP Regulates Various Phenotypes and Insecticidal Activity of Gram-Positive Bacillus thuringiensis

    Directory of Open Access Journals (Sweden)

    Yang Fu

    2018-02-01

    Full Text Available C-di-GMP has been well investigated to play significant roles in the physiology of many Gram-negative bacteria. However, its effect on Gram-positive bacteria is less known. In order to more understand the c-di-GMP functions in Gram-positive bacteria, we have carried out a detailed study on the c-di-GMP-metabolizing enzymes and their physiological functions in Bacillus thuringiensis, a Gram-positive entomopathogenic bacterium that has been applied as an insecticide successfully. We performed a systematic study on the ten putative c-di-GMP-synthesizing enzyme diguanylate cyclases (DGCs and c-di-GMP-degrading enzyme phosphodiesterases (PDEs in B. thuringiensis BMB171, and artificially elevated the intracellular c-di-GMP level in BMB171 by deleting one or more pde genes. We found increasing level of intracellular c-di-GMP exhibits similar activities as those in Gram-negative bacteria, including altered activities in cell motility, biofilm formation, and cell-cell aggregation. Unexpectedly, we additionally found a novel function exhibited by the increasing level of c-di-GMP to promote the insecticidal activity of this bacterium against Helicoverpa armigera. Through whole-genome transcriptome profile analyses, we found that 4.3% of the B. thuringiensis genes were differentially transcribed when c-di-GMP level was increased, and 77.3% of such gene products are involved in some regulatory pathways not reported in other bacteria to date. In summary, our study represents the first comprehensive report on the c-di-GMP-metabolizing enzymes, their effects on phenotypes, and the transcriptome mediated by c-di-GMP in an important Gram-positive bacterium.

  9. Lysinibacillus louembei sp. nov., a spore-forming bacterium isolated from Ntoba Mbodi, alkaline fermented leaves of cassava from the Republic of the Congo

    DEFF Research Database (Denmark)

    Ouoba, Labia Irène I.; Mbozo, Alain B. Vouidibio; Thorsen, Line

    2015-01-01

    . xylanilyticus DSM 23493T and L. odysseyi DSM 18869T was 41%, 16% and 15%, respectively. The internal transcribed spacer-PCR profile of the isolate was different from those of closely related bacteria. The cellwall peptidoglycan type was A4α, L-Lys-D-Asp and the major fatty acids were iso-C15:0, anteiso-C15......Investigation of the microbial diversity of Ntoba Mbodi, an African food made from the alkaline fermentation of cassava leaves, revealed the presence of a Gram-positive, catalase-positive, aerobic, motile and rod-shaped endospore-forming bacterium (NM73) with unusual phenotypic and genotypic......:0, anteiso-C17:0 and iso-C17:0 and iso-C17:1ω10c. The polar lipids included phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphoaminolipid, aminolipid, two phospholipids and two unknown lipids. The predominant menaquinones were MK-7 and MK-6.Ribose was the only whole-cell sugar...

  10. Insights into the extremotolerance of Acinetobacter radioresistens 50v1, a gram-negative bacterium isolated from the Mars Odyssey spacecraft.

    Science.gov (United States)

    McCoy, K B; Derecho, I; Wong, T; Tran, H M; Huynh, T D; La Duc, M T; Venkateswaran, K; Mogul, R

    2012-09-01

    The microbiology of the spacecraft assembly process is of paramount importance to planetary exploration, as the biological contamination that can result from remote-enabled spacecraft carries the potential to impact both life-detection experiments and extraterrestrial evolution. Accordingly, insights into the mechanisms and range of extremotolerance of Acinetobacter radioresistens 50v1, a Gram-negative bacterium isolated from the surface of the preflight Mars Odyssey orbiter, were gained by using a combination of microbiological, enzymatic, and proteomic methods. In summary, A. radioresistens 50v1 displayed a remarkable range of survival against hydrogen peroxide and the sequential exposures of desiccation, vapor and plasma phase hydrogen peroxide, and ultraviolet irradiation. The survival is among the highest reported for non-spore-forming and Gram-negative bacteria and is based upon contributions from the enzyme-based degradation of H(2)O(2) (catalase and alkyl hydroperoxide reductase), energy management (ATP synthase and alcohol dehydrogenase), and modulation of the membrane composition. Together, the biochemical and survival features of A. radioresistens 50v1 support a potential persistence on Mars (given an unintended or planned surface landing of the Mars Odyssey orbiter), which in turn may compromise the scientific integrity of future life-detection missions.

  11. Handling technique of spore-forming bacteria in radiation sterilization. 1. Preparation of spores

    International Nuclear Information System (INIS)

    Koshikawa, Tomihiko

    1994-01-01

    This paper deals with a handling technique of spore-forming bacteria in radiation sterilization. An explanation is given under three sections: (1) life cycle of spore-forming bacteria, medium to form bacterial spores, and colony and purification methods of bacterial spores; (2) methods for measuring the number of bacterial spores and resistance against gamma radiation (D values); and (3) a test method for identifying spore-forming bacteria and a simple identification method. (N.K.)

  12. Higher order structure in the 3'-minor domain of small subunit ribosomal RNAs from a gram negative bacterium, a gram positive bacterium and a eukaryote

    DEFF Research Database (Denmark)

    Douthwaite, S; Christensen, A; Garrett, R A

    1983-01-01

    of additional higher order structure in the renatured free RNA. It can be concluded that a high level of conservation of higher order structure has occurred during the evolution of the gram negative and gram positive eubacteria and the eukaryote in both the double helical regions and the "unstructured" regions...

  13. Aliidiomarina haloalkalitolerans sp. nov., a marine bacterium isolated from coastal surface seawater

    Digital Repository Service at National Institute of Oceanography (India)

    Srinivas, T.N.R.; Nupur; AnilKumar, P.

    A novel Gram-negative, rod shaped, motile, non-sporing strictly aerobic bacterium, designated strain AK5 sup(T), was isolated from a sea water sample collected near Visakhapatnam coast, Bay of Bengal, India. Colonies on marine agar were circular, 3...

  14. Fermentation of glycolate by a pure culture of a strictly anaerobic gram-positive bacterium belonging to the family Lachnospiraceae.

    Science.gov (United States)

    Janssen, Peter H; Hugenholtz, Philip

    2003-05-01

    The component bacteria of a three-membered mixed culture able to ferment glycolate to acetate, propionate and CO(2) were isolated in pure culture. All three strains were strict anaerobes that, on the basis of comparative 16S rRNA gene sequence analysis, belonged to the order Clostridiales in the phylum Firmicutes (low G+C gram-positive bacteria). Two of the strains were not involved in glycolate metabolism. The third, the glycolate-fermenting strain 19gly4 (DSM 11261), was related to members of the family Lachnospiraceae. The cells of strain 19gly4 were oval- to lemon-shaped, 0.85 microm long and 0.65 microm in diameter, occurring singly, in pairs, or in chains of up to 30 cells. Strain 19gly4 fermented glycolate or fumarate to acetate, succinate, and CO(2). Hydrogen was not formed, and strain 19gly4 was able to grow on glycolate in pure culture without any syntrophic hydrogen transfer and without the use of an external electron acceptor. There was no evidence for homoacetogenic metabolism. This bacterium therefore differs in metabolism from previously reported glycolate-utilising anaerobes.

  15. Spore-Forming Thermophilic Bacterium within Artificial Meteorite Survives Entry into the Earth's Atmosphere on FOTON-M4 Satellite Landing Module.

    Science.gov (United States)

    Slobodkin, Alexander; Gavrilov, Sergey; Ionov, Victor; Iliyin, Vyacheslav

    2015-01-01

    One of the key conditions of the lithopanspermia hypothesis is that microorganisms situated within meteorites could survive hypervelocity entry from space through the Earth's atmosphere. So far, all experimental proof of this possibility has been based on tests with sounding rockets which do not reach the transit velocities of natural meteorites. We explored the survival of the spore-forming thermophilic anaerobic bacterium, Thermoanaerobacter siderophilus, placed within 1.4-cm thick basalt discs fixed on the exterior of a space capsule (the METEORITE experiment on the FOTON-M4 satellite). After 45 days of orbital flight, the landing module of the space vehicle returned to Earth. The temperature during the atmospheric transit was high enough to melt the surface of basalt. T. siderophilus survived the entry; viable cells were recovered from 4 of 24 wells loaded with this microorganism. The identity of the strain was confirmed by 16S rRNA gene sequence and physiological tests. This is the first report on the survival of a lifeform within an artificial meteorite after entry from space orbit through Earth's atmosphere at a velocity that closely approached the velocities of natural meteorites. The characteristics of the artificial meteorite and the living object applied in this study can serve as positive controls in further experiments on testing of different organisms and conditions of interplanetary transport.

  16. Spore-Forming Thermophilic Bacterium within Artificial Meteorite Survives Entry into the Earth's Atmosphere on FOTON-M4 Satellite Landing Module.

    Directory of Open Access Journals (Sweden)

    Alexander Slobodkin

    Full Text Available One of the key conditions of the lithopanspermia hypothesis is that microorganisms situated within meteorites could survive hypervelocity entry from space through the Earth's atmosphere. So far, all experimental proof of this possibility has been based on tests with sounding rockets which do not reach the transit velocities of natural meteorites. We explored the survival of the spore-forming thermophilic anaerobic bacterium, Thermoanaerobacter siderophilus, placed within 1.4-cm thick basalt discs fixed on the exterior of a space capsule (the METEORITE experiment on the FOTON-M4 satellite. After 45 days of orbital flight, the landing module of the space vehicle returned to Earth. The temperature during the atmospheric transit was high enough to melt the surface of basalt. T. siderophilus survived the entry; viable cells were recovered from 4 of 24 wells loaded with this microorganism. The identity of the strain was confirmed by 16S rRNA gene sequence and physiological tests. This is the first report on the survival of a lifeform within an artificial meteorite after entry from space orbit through Earth's atmosphere at a velocity that closely approached the velocities of natural meteorites. The characteristics of the artificial meteorite and the living object applied in this study can serve as positive controls in further experiments on testing of different organisms and conditions of interplanetary transport.

  17. Study of the antibacterial effects of chitosans on Bacillus cereus (and its spores) by atomic force microscopy imaging and nanoindentation

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Joao C. [Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Rua Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal); Eaton, Peter, E-mail: peter.eaton@fc.up.pt [REQUIMTE, Departamento de Quimica, Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto (Portugal); Gomes, Ana M.; Pintado, Manuela E.; Xavier Malcata, F. [Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Rua Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal)

    2009-07-15

    Bacillus cereus is a Gram-positive, spore-forming bacterium that is widely distributed in nature. Its intrinsic thermal resistance coupled with the extraordinary resistance against common food preservation techniques makes it one of the most frequent food-poisoning microorganisms causing both intoxications and infections. In order to control B. cereus growth/sporulation, and hence minimize the aforementioned hazards, several antimicrobial compounds have been tested. The aim of this work was to assess by atomic force microscopy (AFM) the relationship between the molecular weight (MW) of chitosan and its antimicrobial activity upon both vegetative and resistance forms of B. cereus. The use of AFM imaging studies helped us to understand how chitosans with different MW act differently upon B. cereus. Higher MW chitosans (628 and 100 kDa) surrounded both forms of B. cereus cells by forming a polymer layer-which eventually led to the death of the vegetative form by preventing the uptake of nutrients yet did not affect the spores since these can survive for extended periods without nutrients. Chitooligosaccharides (COS) (<3 kDa), on the other hand, provoked more visible damages in the B. cereus vegetative form-most probably due to the penetration of the cells by the COS. The use of COS by itself on B. cereus spores was not enough for the destruction of a large number of cells, but it may well weaken the spore structure and its ability to contaminate, by inducing exosporium loss.

  18. Study of the antibacterial effects of chitosans on Bacillus cereus (and its spores) by atomic force microscopy imaging and nanoindentation

    International Nuclear Information System (INIS)

    Fernandes, Joao C.; Eaton, Peter; Gomes, Ana M.; Pintado, Manuela E.; Xavier Malcata, F.

    2009-01-01

    Bacillus cereus is a Gram-positive, spore-forming bacterium that is widely distributed in nature. Its intrinsic thermal resistance coupled with the extraordinary resistance against common food preservation techniques makes it one of the most frequent food-poisoning microorganisms causing both intoxications and infections. In order to control B. cereus growth/sporulation, and hence minimize the aforementioned hazards, several antimicrobial compounds have been tested. The aim of this work was to assess by atomic force microscopy (AFM) the relationship between the molecular weight (MW) of chitosan and its antimicrobial activity upon both vegetative and resistance forms of B. cereus. The use of AFM imaging studies helped us to understand how chitosans with different MW act differently upon B. cereus. Higher MW chitosans (628 and 100 kDa) surrounded both forms of B. cereus cells by forming a polymer layer-which eventually led to the death of the vegetative form by preventing the uptake of nutrients yet did not affect the spores since these can survive for extended periods without nutrients. Chitooligosaccharides (COS) (<3 kDa), on the other hand, provoked more visible damages in the B. cereus vegetative form-most probably due to the penetration of the cells by the COS. The use of COS by itself on B. cereus spores was not enough for the destruction of a large number of cells, but it may well weaken the spore structure and its ability to contaminate, by inducing exosporium loss.

  19. The complete genome sequence of the Gram-positive bacterium Bacillus subtilis

    NARCIS (Netherlands)

    Kunst, F; Ogasawara, N; Moszer, [No Value; Albertini, AM; Alloni, G; Azevedo, [No Value; Bertero, MG; Bessieres, P; Bolotin, A; Borchert, S; Borriss, R; Boursier, L; Brans, A; Brignell, SC; Bron, S; Brouillet, S; Bruschi, CV; Caldwell, B; Capuano, [No Value; Carter, NM; Choi, SK; Codani, JJ; Connerton, IF; Cummings, NJ; Daniel, RA; Denizot, F; Devine, KM; Dusterhoft, A; Ehrlich, SD; Emmerson, PT; Entian, KD; Errington, J; Fabret, C; Ferrari, E; Foulger, D; Fujita, M; Fujita, Y; Fuma, S; Galizzi, A; Galleron, N; Ghim, SY; Glaser, P; Goffeau, A; Golightly, EJ; Grandi, G; Guiseppi, G; Guy, BJ; Haga, K; Haiech, J; Harwood, CR; Henaut, A; Hilbert, H; Holsappel, S; Hosono, S; Hullo, MF; Itaya, M; Jones, L; Joris, B; Karamata, D; Kasahara, Y; KlaerrBlanchard, M; Klein, C; Kobayashi, Y; Koetter, P; Koningstein, G; Krogh, S; Kumano, M; Kurita, K; Lapidus, A; Lardinois, S; Lauber, J; Lazarevic, [No Value; Lee, SM; Levine, A; Liu, H; Masuda, S; Mauel, C; Medigue, C; Medina, N; Mellado, RP; Mizuno, M; Moestl, D; Nakai, S; Noback, M; Noone, D; OReilly, M; Ogawa, K; Ogiwara, A; Oudega, B; Park, SH; Parro, [No Value; Pohl, TM; Portetelle, D; Porwollik, S; Prescott, AM; Presecan, E; Pujic, P; Purnelle, B; Rapoport, G; Rey, M; Reynolds, S; Rieger, M; Rivolta, C; Rocha, E; Roche, B; Rose, M; Sadaie, Y; Sato, T; Scanlan, E; Schleich, S; Schroeter, R; Scoffone, F; Sekiguchi, J; Sekowska, A; Seror, SJ; Serror, P; Shin, BS; Soldo, B; Sorokin, A; Tacconi, E; Takagi, T; Takahashi, H; Takemaru, K; Takeuchi, M; Tamakoshi, A; Tanaka, T; Terpstra, P; Tognoni, A; Tosato, [No Value; Uchiyama, S; Vandenbol, M; Vannier, F; Vassarotti, A; Viari, A; Wambutt, R; Wedler, E; Wedler, H; Weitzenegger, T; Winters, P; Wipat, A; Yamamoto, H; Yamane, K; Yasumoto, K; Yata, K; Yoshida, K; Yoshikawa, HF; Zumstein, E; Yoshikawa, H; Danchin, A

    1997-01-01

    Bacillus subtilis is the best-characterized member of the Gram-positive bacteria. Its genome of 4,214,810 base pairs comprises 4,100 protein-coding genes. Of these protein-coding genes, 53% are represented once, while a quarter of the genome corresponds to several gene families that have been

  20. Desulfotomaculum spp. and related Gram-positive sulfate-reducing bacteria in deep subsurface environments.

    Directory of Open Access Journals (Sweden)

    Thomas eAullo

    2013-12-01

    Full Text Available Gram-positive spore-forming sulfate reducers and particularly members of the genus Desulfotomaculum are commonly found in the subsurface biosphere by culture based and molecular approaches. Due to their metabolic versatility and their ability to persist as endospores. Desulfotomaculum spp. are well adapted for colonizing environments through a slow sedimentation process. Because of their ability to grow autotrophically (H2/CO2 and produce sulfide or acetate, these microorganisms may play key roles in deep lithoautotrophic microbial communities. Available data about Desulfotomaculum spp. and related species from studies carried out from deep freshwater lakes, marine sediments, oligotrophic and organic rich deep geological settings are discussed in this review.

  1. Glycosaminoglycans are involved in pathogen adherence to corneal epithelial cells differently for Gram-positive and Gram-negative bacteria

    Directory of Open Access Journals (Sweden)

    Beatriz García

    2016-11-01

    Full Text Available The epithelium of the cornea is continuously exposed to pathogens, and adhesion to epithelial cells is regarded as an essential first step in bacterial pathogenesis. In this article, the involvement of glycosaminoglycans in the adhesion of various pathogenic bacteria to corneal epithelial cells is analyzed. All microorganisms use glycosaminoglycans as receptors, but arranged in different patterns depending on the Gram-type of the bacterium. The heparan sulfate chains of syndecans are the main receptors, though other molecular species also seem to be involved, particularly in Gram-negative bacteria. Adherence is inhibited differentially by peptides, including heparin binding sequences, indicating the participation of various groups of Gram-positive and -negative adhesins. The length of the saccharides produces a major effect, and low molecular weight chains inhibit the binding of Gram-negative microorganisms but increase the adherence of Gram-positives. Pathogen adhesion appears to occur preferentially through sulfated domains, and is very dependent on N- and 6-O-sulfation of the glucosamine residue and, to a lesser extent, 2-O sulfation of uronic acid. These data show the differential use of corneal receptors, which could facilitate the development of new anti-infective strategies.

  2. Different Use of Cell Surface Glycosaminoglycans As Adherence Receptors to Corneal Cells by Gram Positive and Gram Negative Pathogens

    Science.gov (United States)

    García, Beatriz; Merayo-Lloves, Jesús; Rodríguez, David; Alcalde, Ignacio; García-Suárez, Olivia; Alfonso, José F.; Baamonde, Begoña; Fernández-Vega, Andrés; Vazquez, Fernando; Quirós, Luis M.

    2016-01-01

    The epithelium of the cornea is continuously exposed to pathogens, and adhesion to epithelial cells is regarded as an essential first step in bacterial pathogenesis. In this article, the involvement of glycosaminoglycans in the adhesion of various pathogenic bacteria to corneal epithelial cells is analyzed. All microorganisms use glycosaminoglycans as receptors, but arranged in different patterns depending on the Gram-type of the bacterium. The heparan sulfate chains of syndecans are the main receptors, though other molecular species also seem to be involved, particularly in Gram-negative bacteria. Adherence is inhibited differentially by peptides, including heparin binding sequences, indicating the participation of various groups of Gram-positive, and -negative adhesins. The length of the saccharides produces a major effect, and low molecular weight chains inhibit the binding of Gram-negative microorganisms but increase the adherence of Gram-positives. Pathogen adhesion appears to occur preferentially through sulfated domains, and is very dependent on N- and 6-O-sulfation of the glucosamine residue and, to a lesser extent, 2-O sulfation of uronic acid. These data show the differential use of corneal receptors, which could facilitate the development of new anti-infective strategies. PMID:27965938

  3. Distribution of Paenibacillus larvae spores inside honey bee colonies and its relevance for diagnosis.

    Science.gov (United States)

    Gillard, M; Charriere, J D; Belloy, L

    2008-09-01

    One of the most important factors affecting the development of honey bee colonies is infectious diseases such as American foulbrood (AFB) caused by the spore forming Gram-positive bacterium Paenibacillus larvae. Colony inspections for AFB clinical symptoms are time consuming. Moreover, diseased cells in the early stages of the infection may easily be overlooked. In this study, we investigated whether it is possible to determine the sanitary status of a colony based on analyses of different materials collected from the hive. We analysed 237 bee samples and 67 honey samples originating from 71 colonies situated in 13 apiaries with clinical AFB occurrences. We tested whether a difference in spore load among bees inside the whole hive exists and which sample material related to its location inside the hive was the most appropriate for an early AFB diagnosis based on the culture method. Results indicated that diagnostics based on analysis of honey samples and bees collected at the hive entrance are of limited value as only 86% and 83%, respectively, of samples from AFB-symptomatic colonies were positive. Analysis of bee samples collected from the brood nest, honey chamber, and edge frame allowed the detection of all colonies showing AFB clinical symptoms. Microbiological analysis showed that more than one quarter of samples collected from colonies without AFB clinical symptoms were positive for P. larvae. Based on these results, we recommend investigating colonies by testing bee samples from the brood nest, edge frame or honey chamber for P. larvae spores.

  4. Identification of Multiple Soluble Fe(III Reductases in Gram-Positive Thermophilic Bacterium Thermoanaerobacter indiensis BSB-33

    Directory of Open Access Journals (Sweden)

    Subrata Pal

    2014-01-01

    Full Text Available Thermoanaerobacter indiensis BSB-33 has been earlier shown to reduce Fe(III and Cr(VI anaerobically at 60°C optimally. Further, the Gram-positive thermophilic bacterium contains Cr(VI reduction activity in both the membrane and cytoplasm. The soluble fraction prepared from T. indiensis cells grown at 60°C was found to contain the majority of Fe(III reduction activity of the microorganism and produced four distinct bands in nondenaturing Fe(III reductase activity gel. Proteins from each of these bands were partially purified by chromatography and identified by mass spectrometry (MS with the help of T. indiensis proteome sequences. Two paralogous dihydrolipoamide dehydrogenases (LPDs, thioredoxin reductase (Trx, NADP(H-nitrite reductase (Ntr, and thioredoxin disulfide reductase (Tdr were determined to be responsible for Fe(III reductase activity. Amino acid sequence and three-dimensional (3D structural similarity analyses of the T. indiensis Fe(III reductases were carried out with Cr(VI reducing proteins from other bacteria. The two LPDs and Tdr showed very significant sequence and structural identity, respectively, with Cr(VI reducing dihydrolipoamide dehydrogenase from Thermus scotoductus and thioredoxin disulfide reductase from Desulfovibrio desulfuricans. It appears that in addition to their iron reducing activity T. indiensis LPDs and Tdr are possibly involved in Cr(VI reduction as well.

  5. Gram-positive bacteria persisting in the food production environment

    DEFF Research Database (Denmark)

    Knøchel, Susanne; Harmsen, Morten; Knudsen, Bettina

    2008-01-01

    Many gram-positive bacteria are able to form aggregates or biofilms and resist external stress factors and some gram-positive pathogenic bacteria such as Listeria monocytogenes and Bacillus cereus may persist in the food production environment for extended periods. Most research has focussed...

  6. Lipoquinones of some spore-forming rods, lactic-acid bacteria and actinomycetes.

    Science.gov (United States)

    Hess, A; Holländer, R; Mannheim, W

    1979-11-01

    The respiratory quinones of 73 strains of Gram-positive bacteria including spore-forming rods, lactic-acid bacteria and actinomyctes were examined. Menaquinones with seven isoprenoid units (MK-7) were the main quinone type found in representatives of the genus Bacillus and in Sporolactobacillus inulinus. However, a strain of B. thuringiensis produced MK-8 in addition to MK-7, and strains of B. lentus and B. pantothenticus appeared to produce MK-9 and MK-8, respectively, with no MK-7. In the clostridia and lactic-acid bacteria, no quinones were found, except in Pediococcus cerevisiae NCTC 8066 and Lactobacillus casei subsp. rhamnosus ATCC 7469, which contained menaquinones, and Streptococcus faecalis NCTC 775 and HIM 478-1, which contained demethylmenaquinones, in relatively low concentrations. Menaquinones were also found in the actinomycetes (except Actinomyces odontolyticus and Bifidobacterium bifidum which did not produce any quinones) and in Protaminobacter alboflavus ATCC 8458, the so-called Actinobacillus actinoides ATCC 15900 and Noguchia granulosis NCTC 10559.

  7. Enzymes produced by halotolerant spore-forming gram-positive bacterial strains isolated from a resting habitat (Restinga de Jurubatiba) in Rio de Janeiro, Brazil: focus on proteases.

    Science.gov (United States)

    D Santos, Anderson Fragoso; Pacheco, Clarissa Almeida; Valle, Roberta D Santos; Seldin, Lucy; D Santos, André Luis Souza

    2014-12-01

    The screening for hydrolases-producing, halotolerant, and spore-forming gram-positive bacteria from the root, rhizosphere, and non-rhizosphere soil of Blutaparon portulacoides, a plant found in the Restinga de Jurubatiba located at the northern region of Rio de Janeiro State, Brazil, resulted in the isolation of 22 strains. These strains were identified as Halobacillus blutaparonensis (n = 2), Oceanobacillus picturae (n = 5), and Oceanobacillus iheyensis (n = 15), and all showed the ability to produce different extracellular enzymes. A total of 20 isolates (90.9 %) showed activity for protease, 5 (22.7 %) for phytase, 3 (13.6 %) for cellulase, and 2 (9.1 %) for amylase. Some bacterial strains were capable of producing three (13.6 %) or two (9.1 %) distinct hydrolytic enzymes. However, no bacterial strain with ability to produce esterase and DNase was observed. The isolate designated M9, belonging to the species H. blutaparonensis, was the best producer of protease and also yielded amylase and phytase. This strain was chosen for further studies regarding its protease activity. The M9 strain produced similar amounts of protease when grown either without or with different NaCl concentrations (from 0.5 to 10 %). A simple inspection of the cell-free culture supernatant by gelatin-sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed the presence of three major alkaline proteases of 40, 50, and 70 kDa, which were fully inhibited by phenylmethylsulfonyl fluoride (PMSF) and tosyl-L-phenylalanine chloromethyl ketone (TPCK) (two classical serine protease inhibitors). The secreted proteases were detected in a wide range of temperature (from 4 to 45 °C) and their hydrolytic activities were stimulated by NaCl (up to 10 %). The serine proteases produced by the M9 strain cleaved gelatin, casein, albumin, and hemoglobin, however, in different extensions. Collectively, these results suggest the potential use of the M9 strain in biotechnological

  8. Live-imaging of Bacillus subtilis spore germination and outgrowth

    NARCIS (Netherlands)

    Pandey, R.

    2014-01-01

    Spores of Gram-positive bacteria such as Bacillus and Clostridium cause huge economic losses to the food industry. In food products, spores survive under food preservation conditions and subsequent germination and outgrowth eventually causes food spoilage. Therefore efforts are being made to

  9. Microbiological method for radiation sterilization (II). Identification procedure of gram positive bacteria by using BBL CRYSTAL GP identification kit

    International Nuclear Information System (INIS)

    Koshikawa, Tomihiko

    2004-01-01

    The part II in this title series describes details of the commercially available BBL CRYSTAL GP Identification Kit with the software (Becton, Dickinson and Co., Ltd.), by which identification of Gram positive bacteria as well as their number becoming easier in the radiation sterilization of medical devices. Isolation of a bacterium has to be confirmed by microscopy and its Gram positive property, by the Gram staining. The exponentially growing bacteria are to be inoculated in the Kit and cultured for 18-24 hr at 37 deg C with the lid attached by substrates for identification. Reactions to substrates are to be judged by CRYSTAL auto-reader, which is further to be searched by the computer software (code-book) for final identification. For possible misidentification, re-isolation of the bacterium, prolonged culture, concentrated inoculation and re-consideration for ranking of identification the software provides are necessary as well as other identification approaches. Representative bacteria as the bioburden are spp. of Bacilli, Corynebacteria, Staphylococci and Micrococci. (N.I.)

  10. Comparative Proteomic Analysis of Desulfotomaculum reducens MI-1: Insights into the Metabolic Versatility of a Gram-positive Sulfate and Metal-reducing Bacterium

    Directory of Open Access Journals (Sweden)

    Anne Elyse Otwell

    2016-02-01

    Full Text Available The proteomes of the metabolically versatile and poorly characterized Gram-positive bacterium Desulfotomaculum reducens MI-1 were compared across four cultivation conditions including sulfate reduction, soluble Fe(III reduction, insoluble Fe(III reduction, and pyruvate fermentation. Collectively across conditions, we observed at high confidence ~38% of genome-encoded proteins. Here, we focus on proteins that display significant differential abundance on conditions tested. To the best of our knowledge, this is the first full-proteome study focused on a Gram-positive organism grown either on sulfate or metal-reducing conditions. Several proteins with uncharacterized function encoded within heterodisulfide reductase (hdr-containing loci were upregulated on either sulfate (Dred_0633-4, Dred_0689-90, and Dred_1325-30 or Fe(III-citrate-reducing conditions (Dred_0432-3 and Dred_1778-84. Two of these hdr-containing loci display homology to recently described flavin-based electron bifurcation (FBEB pathways (Dred_1325-30 and Dred_1778-84. Additionally, we propose that a cluster of proteins, which is homologous to a described FBEB lactate dehydrogenase (LDH complex, is performing lactate oxidation in D. reducens (Dred_0367-9. Analysis of the putative sulfate reduction machinery in D. reducens revealed that most of these proteins are constitutively expressed across cultivation conditions tested. In addition, peptides from the single multiheme c-type cytochrome (MHC in the genome were exclusively observed on the insoluble Fe(III condition, suggesting that this MHC may play a role in reduction of insoluble metals.

  11. Discrimination of Spore-Forming Bacilli Using spoIVA

    Science.gov (United States)

    Venkateswaran, Kasthuri; LaDuc, Myron; Stuecker, Tara

    2009-01-01

    A method of discriminating between spore-forming and non-spore-forming bacteria is based on a combination of simultaneous sporulation-specific and non-sporulation-specific quantitative polymerase chain reactions (Q-PCRs). The method was invented partly in response to the observation that for the purposes of preventing or reducing biological contamination affecting many human endeavors, ultimately, only the spore-forming portions of bacterial populations are the ones that are problematic (or, at least, more problematic than are the non-spore-forming portions). In some environments, spore-forming bacteria constitute small fractions of the total bacterial populations. The use of sporulation-specific primers in Q-PCR affords the ability to assess the spore-forming fraction of a bacterial population present in an environment of interest. This assessment can provide a more thorough and accurate understanding of the bacterial contamination in the environment, thereby making it possible to focus contamination- testing, contamination-prevention, sterilization, and decontamination resources more economically and efficiently. The method includes the use of sporulation-specific primers in the form of designed, optimized deoxyribonucleic acid (DNA) oligonucleotides specific for the bacterial spoIVA gene (see table). [In "spoIVA," "IV" signifies Roman numeral four and the entire quoted name refers to gene A for the fourth stage of sporulation.] These primers are mixed into a PCR cocktail with a given sample of bacterial cells. A control PCR cocktail into which are mixed universal 16S rRNA primers is also prepared. ["16S rRNA" denotes a ribosomal ribonucleic acid (rRNA) sequence that is common to all organisms.] Following several cycles of heating and cooling according to the PCR protocol to amplify amounts of DNA molecules, the amplification products can be analyzed to determine the types of bacterial cells present within the samples. If the amplification product is strong

  12. Molecular evolution of the nif gene cluster carrying nifI1 and nifI2 genes in the Gram-positive phototrophic bacterium Heliobacterium chlorum.

    Science.gov (United States)

    Enkh-Amgalan, Jigjiddorj; Kawasaki, Hiroko; Seki, Tatsuji

    2006-01-01

    A major nif cluster was detected in the strictly anaerobic, Gram-positive phototrophic bacterium Heliobacterium chlorum. The cluster consisted of 11 genes arranged within a 10 kb region in the order nifI1, nifI2, nifH, nifD, nifK, nifE, nifN, nifX, fdx, nifB and nifV. The phylogenetic position of Hbt. chlorum was the same in the NifH, NifD, NifK, NifE and NifN trees; Hbt. chlorum formed a cluster with Desulfitobacterium hafniense, the closest neighbour of heliobacteria based on the 16S rRNA phylogeny, and two species of the genus Geobacter belonging to the Deltaproteobacteria. Two nifI genes, known to occur in the nif clusters of methanogenic archaea between nifH and nifD, were found upstream of the nifH gene of Hbt. chlorum. The organization of the nif operon and the phylogeny of individual and concatenated gene products showed that the Hbt. chlorum nif operon carrying nifI genes upstream of the nifH gene was an intermediate between the nif operon with nifI downstream of nifH (group II and III of the nitrogenase classification) and the nif operon lacking nifI (group I). Thus, the phylogenetic position of Hbt. chlorum nitrogenase may reflect an evolutionary stage of a divergence of the two nitrogenase groups, with group I consisting of the aerobic diazotrophs and group II consisting of strictly anaerobic prokaryotes.

  13. Bio sorption of some Rare Earth Elements and Yttrium by Gram Positive and Gram Negative Bacteria

    International Nuclear Information System (INIS)

    Ibrahim, H.A.

    2012-01-01

    The separate bio sorption of the REEs La, Sm, Eu and Dy together with yttrium upon the Gram positive bacteria Bacillus subtilis (B.subtilis) and Bacillus Licheniformis (B. Licheniformis),the Gram negative bacterium Escherichia coli (E. coli ) and Saccharomyces cervisiae (Yeast) was studied. The revelant factors of ph 1-6, contact time (30-180 min), the initial rare earth concentration (50-200 mg/l) have been studied. The amount of the accumulated element was strongly affected by its concentration.In addition, bio sorptive fractionation of Y and the studied REEs from a solution containing a mixture of these elements was also studied. From the obtained data, it was found that Langmuir isotherm model for both B.licheniformis and E.coli gives a best fit for the studied elements over the working range of concentration (50-200 mg/I). Transmission electron microscopy exhibited accumulation throughout the bacterial cell with some granular deposits in both the cell periphery and cytoplasm

  14. Septicemia caused by the gram-negative bacterium CDC IV c-2 in an immunocompromised human.

    OpenAIRE

    Dan, M; Berger, S A; Aderka, D; Levo, Y

    1986-01-01

    A 37-year-old man with plasma cell leukemia developed nonfatal septicemia caused by the gram-negative bacterium CDC IV c-2. Recovery followed appropriate treatment with antibiotics. The biochemical features of this organism are reviewed.

  15. Desulfotomaculum arcticum sp nov., a novel spore-formin, moderately thermophilic, sulfate-reducing bacterium isolated from a permanently cold fjord sediment of Svalbard

    DEFF Research Database (Denmark)

    Vandieken, V.; Knoblauch, C.; Jørgensen, BB

    2006-01-01

    Strain 15 T is a novel spore-forming, sulfate-reducing bacterium isolated from a permanently cold fjord sediment of Svalbard. Sulfate could be replaced by sulfite or thiosulfate. Hydrogen, formate, lactate, propionate, butyrate, hexanoate, methanol, ethanol, propanol, butanol, pyruvate, malate, s...... related to Desulfotomaculum thermosapovorans MLF(T) (93-5% 16S rRNA gene sequence similarity). Strain 15 T represents a novel species, for which the name Desulfotomaculurn arcticum sp. nov. is proposed. The type strain is strain 15 T (=DSM 17038(T)=jCM 12923(T))....

  16. Procalcitonin levels in gram-positive, gram-negative, and fungal bloodstream infections.

    Science.gov (United States)

    Leli, Christian; Ferranti, Marta; Moretti, Amedeo; Al Dhahab, Zainab Salim; Cenci, Elio; Mencacci, Antonella

    2015-01-01

    Procalcitonin (PCT) can discriminate bacterial from viral systemic infections and true bacteremia from contaminated blood cultures. The aim of this study was to evaluate PCT diagnostic accuracy in discriminating Gram-positive, Gram-negative, and fungal bloodstream infections. A total of 1,949 samples from patients with suspected bloodstream infections were included in the study. Median PCT value in Gram-negative (13.8 ng/mL, interquartile range (IQR) 3.4-44.1) bacteremias was significantly higher than in Gram-positive (2.1 ng/mL, IQR 0.6-7.6) or fungal (0.5 ng/mL, IQR 0.4-1) infections (P Gram-negatives from Gram-positives at the best cut-off value of 10.8 ng/mL and an AUC of 0.944 (95% CI 0.919-0.969, P Gram-negatives from fungi at the best cut-off of 1.6 ng/mL. Additional results showed a significant difference in median PCT values between Enterobacteriaceae and nonfermentative Gram-negative bacteria (17.1 ng/mL, IQR 5.9-48.5 versus 3.5 ng/mL, IQR 0.8-21.5; P Gram-negative from Gram-positive and fungal bloodstream infections. Nevertheless, its utility to predict different microorganisms needs to be assessed in further studies.

  17. Gram-negative, but not Gram-positive, bacteria elicit strong PGE2 production in human monocytes.

    Science.gov (United States)

    Hessle, Christina C; Andersson, Bengt; Wold, Agnes E

    2003-12-01

    Gram-positive and Gram-negative bacteria induce different cytokine patterns in human mononuclear cells. We have seen that Gram-positives preferentially induce IL-12 and TNF-alpha, whereas Gram-negatives induce more IL-10, IL-6, and IL-8. In this study, we compared the capacity of these two groups of bacteria to induce PGE2. Monocytes stimulated with Gram-negative bacterial species induced much more PGE2 than did Gram-positive bacteria (5600 +/- 330 vs. 1700 +/- 670 pg/mL, p Gram-positive and Gram-negative bacteria. We suggest that Gram-positive and Gram-negative bacteria may stimulate different innate effector functions; Gram-positive bacteria promoting cell-mediated effector functions whereas Gram-negative bacteria inducing mediators inhibiting the same.

  18. (Per)chlorate reduction by an acetogenic bacterium, Sporomusa sp., isolated from an underground gas storage.

    KAUST Repository

    Balk, Melike

    2010-08-03

    A mesophilic bacterium, strain An4, was isolated from an underground gas storage reservoir with methanol as substrate and perchlorate as electron acceptor. Cells were Gram-negative, spore-forming, straight to curved rods, 0.5-0.8 microm in diameter, and 2-8 microm in length, growing as single cells or in pairs. The cells grew optimally at 37 degrees C, and the pH optimum was around 7. Strain An4 converted various alcohols, organic acids, fructose, acetoin, and H(2)/CO(2) to acetate, usually as the only product. Succinate was decarboxylated to propionate. The isolate was able to respire with (per)chlorate, nitrate, and CO(2). The G+C content of the DNA was 42.6 mol%. Based on the 16S rRNA gene sequence analysis, strain An4 was most closely related to Sporomusa ovata (98% similarity). The bacterium reduced perchlorate and chlorate completely to chloride. Key enzymes, perchlorate reductase and chlorite dismutase, were detected in cell-free extracts.

  19. (Per)chlorate reduction by an acetogenic bacterium, Sporomusa sp., isolated from an underground gas storage.

    KAUST Repository

    Balk, Melike; Mehboob, Farrakh; van Gelder, Antonie H; Rijpstra, W Irene C; Damsté , Jaap S Sinninghe; Stams, Alfons J M

    2010-01-01

    A mesophilic bacterium, strain An4, was isolated from an underground gas storage reservoir with methanol as substrate and perchlorate as electron acceptor. Cells were Gram-negative, spore-forming, straight to curved rods, 0.5-0.8 microm in diameter, and 2-8 microm in length, growing as single cells or in pairs. The cells grew optimally at 37 degrees C, and the pH optimum was around 7. Strain An4 converted various alcohols, organic acids, fructose, acetoin, and H(2)/CO(2) to acetate, usually as the only product. Succinate was decarboxylated to propionate. The isolate was able to respire with (per)chlorate, nitrate, and CO(2). The G+C content of the DNA was 42.6 mol%. Based on the 16S rRNA gene sequence analysis, strain An4 was most closely related to Sporomusa ovata (98% similarity). The bacterium reduced perchlorate and chlorate completely to chloride. Key enzymes, perchlorate reductase and chlorite dismutase, were detected in cell-free extracts.

  20. Procalcitonin Levels in Gram-Positive, Gram-Negative, and Fungal Bloodstream Infections

    Directory of Open Access Journals (Sweden)

    Christian Leli

    2015-01-01

    Full Text Available Procalcitonin (PCT can discriminate bacterial from viral systemic infections and true bacteremia from contaminated blood cultures. The aim of this study was to evaluate PCT diagnostic accuracy in discriminating Gram-positive, Gram-negative, and fungal bloodstream infections. A total of 1,949 samples from patients with suspected bloodstream infections were included in the study. Median PCT value in Gram-negative (13.8 ng/mL, interquartile range (IQR 3.4–44.1 bacteremias was significantly higher than in Gram-positive (2.1 ng/mL, IQR 0.6–7.6 or fungal (0.5 ng/mL, IQR 0.4–1 infections (P<0.0001. Receiver operating characteristic analysis showed an area under the curve (AUC for PCT of 0.765 (95% CI 0.725–0.805, P<0.0001 in discriminating Gram-negatives from Gram-positives at the best cut-off value of 10.8 ng/mL and an AUC of 0.944 (95% CI 0.919–0.969, P<0.0001 in discriminating Gram-negatives from fungi at the best cut-off of 1.6 ng/mL. Additional results showed a significant difference in median PCT values between Enterobacteriaceae and nonfermentative Gram-negative bacteria (17.1 ng/mL, IQR 5.9–48.5 versus 3.5 ng/mL, IQR 0.8–21.5; P<0.0001. This study suggests that PCT may be of value to distinguish Gram-negative from Gram-positive and fungal bloodstream infections. Nevertheless, its utility to predict different microorganisms needs to be assessed in further studies.

  1. Indole and 3-indolylacetonitrile inhibit spore maturation in Paenibacillus alvei

    Directory of Open Access Journals (Sweden)

    Cho Moo

    2011-05-01

    Full Text Available Abstract Background Bacteria use diverse signaling molecules to ensure the survival of the species in environmental niches. A variety of both Gram-positive and Gram-negative bacteria produce large quantities of indole that functions as an intercellular signal controlling diverse aspects of bacterial physiology. Results In this study, we sought a novel role of indole in a Gram-positive bacteria Paenibacillus alvei that can produce extracellular indole at a concentration of up to 300 μM in the stationary phase in Luria-Bertani medium. Unlike previous studies, our data show that the production of indole in P. alvei is strictly controlled by catabolite repression since the addition of glucose and glycerol completely turns off the indole production. The addition of exogenous indole markedly inhibits the heat resistance of P. alvei without affecting cell growth. Observation of cell morphology with electron microscopy shows that indole inhibits the development of spore coats and cortex in P. alvei. As a result of the immature spore formation of P. alvei, indole also decreases P. alvei survival when exposed to antibiotics, low pH, and ethanol. Additionally, indole derivatives also influence the heat resistance; for example, a plant auxin, 3-indolylacetonitrile dramatically (2900-fold decreased the heat resistance of P. alvei, while another auxin 3-indoleacetic acid had a less significant influence on the heat resistance of P. alvei. Conclusions Together, our results demonstrate that indole and plant auxin 3-indolylacetonitrile inhibit spore maturation of P. alvei and that 3-indolylacetonitrile presents an opportunity for the control of heat and antimicrobial resistant spores of Gram-positive bacteria.

  2. Selenoproteins in Archaea and Gram-positive bacteria.

    Science.gov (United States)

    Stock, Tilmann; Rother, Michael

    2009-11-01

    Selenium is an essential trace element for many organisms by serving important catalytic roles in the form of the 21st co-translationally inserted amino acid selenocysteine. It is mostly found in redox-active proteins in members of all three domains of life and analysis of the ever-increasing number of genome sequences has facilitated identification of the encoded selenoproteins. Available data from biochemical, sequence, and structure analyses indicate that Gram-positive bacteria synthesize and incorporate selenocysteine via the same pathway as enterobacteria. However, recent in vivo studies indicate that selenocysteine-decoding is much less stringent in Gram-positive bacteria than in Escherichia coli. For years, knowledge about the pathway of selenocysteine synthesis in Archaea and Eukarya was only fragmentary, but genetic and biochemical studies guided by analysis of genome sequences of Sec-encoding archaea has not only led to the characterization of the pathways but has also shown that they are principally identical. This review summarizes current knowledge about the metabolic pathways of Archaea and Gram-positive bacteria where selenium is involved, about the known selenoproteins, and about the respective pathways employed in selenoprotein synthesis.

  3. Isolation and characterization of a new hydrogen-utilizing bacterium from the rumen.

    Science.gov (United States)

    Rieu-Lesme, F; Fonty, G; Doré, J

    1995-01-01

    A new H2/CO2-utilizing acetogenic bacterium was isolated from the rumen of a mature deer. This is the first report of a spore-forming Gram-negative bacterial species from the rumen. The organism was a strictly anaerobic, motile rod and was able to grow autotrophically on hydrogen and carbon dioxide. Acetate was the major product detected. Glucose, fructose and lactate were also fermented heterotrophically. The optimum pH for growth was 7.0-7.5, and the optimum temperature was 37-42 degrees C. Yeast extract was required for growth and rumen fluid was highly stimulatory. The DNA base ratio was 52.9 +/- 0.5 mol% G+C. On the basis of these characteristics and fermentation products, the isolate was considered to be different from acetogenic bacteria described previously.

  4. Spore Coat Architecture of Clostridium novyi-NT spores

    Energy Technology Data Exchange (ETDEWEB)

    Plomp, M; McCafferey, J; Cheong, I; Huang, X; Bettegowda, C; Kinzler, K; Zhou, S; Vogelstein, B; Malkin, A

    2007-05-07

    Spores of the anaerobic bacterium Clostridium novyi-NT are able to germinate in and destroy hypoxic regions of tumors in experimental animals. Future progress in this area will benefit from a better understanding of the germination and outgrowth processes that are essential for the tumorilytic properties of these spores. Towards this end, we have used both transmission electron microscopy and atomic force microscopy to determine the structure of dormant as well as germinating spores. We found that the spores are surrounded by an amorphous layer intertwined with honeycomb parasporal layers. Moreover, the spore coat layers had apparently self-assembled and this assembly was likely to be governed by crystal growth principles. During germination and outgrowth, the honeycomb layers as well as the underlying spore coat and undercoat layers sequentially dissolved until the vegetative cell was released. In addition to their implications for understanding the biology of C. novyi-NT, these studies document the presence of proteinaceous growth spirals in a biological organism.

  5. Synergistic action of cinnamaldehyde with silver nanoparticles against spore-forming bacteria: a case for judicious use of silver nanoparticles for antibacterial applications

    Directory of Open Access Journals (Sweden)

    Ghosh IN

    2013-12-01

    Full Text Available Indro Neil Ghosh,1,* Supriya Deepak Patil,1,* Tarun Kumar Sharma,1,2 Santosh Kumar Srivastava,1 Ranjana Pathania,1 Naveen Kumar Navani11Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, 2Center for Biodesign and Diagnostics, Translational Health Science and Technology Institute, Gurgaon Haryana, India*These authors contributed equally to this workAbstract: Silver has long been advocated as an effective antimicrobial. However, toxicity issues with silver have led to limited use of silver in nanoform, especially for food preservation. With the aim of exploring combinatorial options that could increase the antibacterial potency of silver nanoparticles and reduce the effective dosage of silver, we evaluated the extent of synergy that a combination of silver nanoparticles and an essential oil representative (cinnamaldehyde could offer. A battery of gram-positive and gram-negative bacterial strains was utilized for antibacterial assays, and extents of synergism were calculated from fractional inhibitory concentration indices. The activity of nanoparticles was greatly enhanced when utilized in the presence of cinnamaldehyde. We observed combinatorial effects that were strongly additive against all the bacterial strains tested, and genuine synergy was found against spore forming Bacillus cereus and Clostridium perfringens – bacterial strains associated with release of cytotoxins in contaminated food and known for their persistence. Bacterial kill curve analysis revealed a very fast bactericidal action when a combination of two agents was used. The electron and atomic force microscopy also revealed extensive damage to the bacterial cell envelop in the presence of both agents. We also performed hemolysis assays to investigate and approximate the extent of toxicity exhibited by the two agents, and observed no adverse effect at the concentrations required for synergy. This study shows that safe levels of silver in

  6. How bacterial cell division might cheat turgor pressure - a unified mechanism of septal division in Gram-positive and Gram-negative bacteria.

    Science.gov (United States)

    Erickson, Harold P

    2017-08-01

    An important question for bacterial cell division is how the invaginating septum can overcome the turgor force generated by the high osmolarity of the cytoplasm. I suggest that it may not need to. Several studies in Gram-negative bacteria have shown that the periplasm is isoosmolar with the cytoplasm. Indirect evidence suggests that this is also true for Gram-positive bacteria. In this case the invagination of the septum takes place within the uniformly high osmotic pressure environment, and does not have to fight turgor pressure. A related question is how the V-shaped constriction of Gram-negative bacteria relates to the plate-like septum of Gram-positive bacteria. I collected evidence that Gram-negative bacteria have a latent capability of forming plate-like septa, and present a model in which septal division is the basic mechanism in both Gram-positive and Gram-negative bacteria. © 2017 WILEY Periodicals, Inc.

  7. Genome sequence of Desulfitobacterium hafniense DCB-2, a Gram-positive anaerobe capable of dehalogenation and metal reduction

    Directory of Open Access Journals (Sweden)

    Kim Sang-Hoon

    2012-02-01

    Full Text Available Abstract Background The genome of the Gram-positive, metal-reducing, dehalorespiring Desulfitobacterium hafniense DCB-2 was sequenced in order to gain insights into its metabolic capacities, adaptive physiology, and regulatory machineries, and to compare with that of Desulfitobacterium hafniense Y51, the phylogenetically closest strain among the species with a sequenced genome. Results The genome of Desulfitobacterium hafniense DCB-2 is composed of a 5,279,134-bp circular chromosome with 5,042 predicted genes. Genome content and parallel physiological studies support the cell's ability to fix N2 and CO2, form spores and biofilms, reduce metals, and use a variety of electron acceptors in respiration, including halogenated organic compounds. The genome contained seven reductive dehalogenase genes and four nitrogenase gene homologs but lacked the Nar respiratory nitrate reductase system. The D. hafniense DCB-2 genome contained genes for 43 RNA polymerase sigma factors including 27 sigma-24 subunits, 59 two-component signal transduction systems, and about 730 transporter proteins. In addition, it contained genes for 53 molybdopterin-binding oxidoreductases, 19 flavoprotein paralogs of the fumarate reductase, and many other FAD/FMN-binding oxidoreductases, proving the cell's versatility in both adaptive and reductive capacities. Together with the ability to form spores, the presence of the CO2-fixing Wood-Ljungdahl pathway and the genes associated with oxygen tolerance add flexibility to the cell's options for survival under stress. Conclusions D. hafniense DCB-2's genome contains genes consistent with its abilities for dehalogenation, metal reduction, N2 and CO2 fixation, anaerobic respiration, oxygen tolerance, spore formation, and biofilm formation which make this organism a potential candidate for bioremediation at contaminated sites.

  8. Comparison of hand hygiene procedures for removing Bacillus cereus spores.

    Science.gov (United States)

    Sasahara, Teppei; Hayashi, Shunji; Hosoda, Kouichi; Morisawa, Yuji; Hirai, Yoshikazu

    2014-01-01

    Bacillus cereus is a spore-forming bacterium. B. cereus occasionally causes nosocomial infections, in which hand contamination with the spores plays an important role. Therefore, hand hygiene is the most important practice for controlling nosocomial B. cereus infections. This study aimed to determine the appropriate hand hygiene procedure for removing B. cereus spores. Thirty volunteers' hands were experimentally contaminated with B. cereus spores, after which they performed 6 different hand hygiene procedures. We compared the efficacy of the procedures in removing the spores from hands. The alcohol-based hand-rubbing procedures scarcely removed them. The soap washing procedures reduced the number of spores by more than 2 log10. Extending the washing time increased the spore-removing efficacy of the washing procedures. There was no significant difference in efficacy between the use of plain soap and antiseptic soap. Handwashing with soap is appropriate for removing B. cereus spores from hands. Alcohol-based hand-rubbing is not effective.

  9. Transformation of gram positive bacteria by sonoporation

    Science.gov (United States)

    Yang, Yunfeng; Li, Yongchao

    2014-03-11

    The present invention provides a sonoporation-based method that can be universally applied for delivery of compounds into Gram positive bacteria. Gram positive bacteria which can be transformed by sonoporation include, for example, Bacillus, Streptococcus, Acetobacterium, and Clostridium. Compounds which can be delivered into Gram positive bacteria via sonoporation include nucleic acids (DNA or RNA), proteins, lipids, carbohydrates, viruses, small organic and inorganic molecules, and nano-particles.

  10. Positive role of peptidoglycan breaks in lactococcal biofilm formation

    NARCIS (Netherlands)

    Mercier, C; Durrieu, C; Briandet, R; Domakova, E; Tremblay, J; Buist, G; Kulakauskas, S

    2002-01-01

    Bacterial attachment to solid matrices depends on adhesive molecules present on the cell surface. Here we establish a positive correlation between peptidoglycan (PG) breaks, rather than particular molecules, and biofilm-forming capacity in the Gram-positive bacterium Lactococcus lactis. The L.

  11. Handling technique of spore-forming bacteria in radiation sterilization. 2. Determination of numbers and radiation resistance of spores

    International Nuclear Information System (INIS)

    Koshikawa, Tomihiko

    1994-01-01

    Stepwise ten-fold dilution of bacterial solution is required in the determination of bacterial spores. For this, the selection of diluted solution is important according to the purpose of experiment. First, the preparation of suspension of bacterial spores and selection of diluted solution are presented. Then, a method for determining the number of bacterial spores in materials is outlined in terms of dilution methods of bacterial solution (shaking and homogenization) and application method of diluted solution to the plating medium. Finally, a method for determining radiation resistance of spore-forming bacteria is explained according to the measurement conditions (suspension of bacterial spores and filters applied with bacterial spores). (N.K.)

  12. Handling technique of spore-forming bacteria in radiation sterilization. 2. Determination of numbers and radiation resistance of spores

    Energy Technology Data Exchange (ETDEWEB)

    Koshikawa, Tomihiko [Japan Radioisotope Association, Shiga (Japan). Koka Laboratory

    1994-12-01

    Stepwise ten-fold dilution of bacterial solution is required in the determination of bacterial spores. For this, the selection of diluted solution is important according to the purpose of experiment. First, the preparation of suspension of bacterial spores and selection of diluted solution are presented. Then, a method for determining the number of bacterial spores in materials is outlined in terms of dilution methods of bacterial solution (shaking and homogenization) and application method of diluted solution to the plating medium. Finally, a method for determining radiation resistance of spore-forming bacteria is explained according to the measurement conditions (suspension of bacterial spores and filters applied with bacterial spores). (N.K.).

  13. Diagnosing periprosthetic infection: false-positive intraoperative Gram stains.

    Science.gov (United States)

    Oethinger, Margret; Warner, Debra K; Schindler, Susan A; Kobayashi, Hideo; Bauer, Thomas W

    2011-04-01

    Intraoperative Gram stains have a reported low sensitivity but high specificity when used to help diagnose periprosthetic infections. In early 2008, we recognized an unexpectedly high frequency of apparent false-positive Gram stains from revision arthroplasties. The purpose of this report is to describe the cause of these false-positive test results. We calculated the sensitivity and specificity of all intraoperative Gram stains submitted from revision arthroplasty cases during a 3-month interval using microbiologic cultures of the same samples as the gold standard. Methods of specimen harvesting, handling, transport, distribution, specimen processing including tissue grinding/macerating, Gram staining, and interpretation were studied. After a test modification, results of specimens were prospectively collected for a second 3-month interval, and the sensitivity and specificity of intraoperative Gram stains were calculated. The retrospective review of 269 Gram stains submitted from revision arthroplasties indicated historic sensitivity and specificity values of 23% and 92%, respectively. Systematic analysis of all steps of the procedure identified Gram-stained but nonviable bacteria in commercial broth reagents used as diluents for maceration of periprosthetic membranes before Gram staining and culture. Polymerase chain reaction and sequencing showed mixed bacterial DNA. Evaluation of 390 specimens after initiating standardized Millipore filtering of diluent fluid revealed a reduced number of positive Gram stains, yielding 9% sensitivity and 99% specificity. Clusters of false-positive Gram stains have been reported in other clinical conditions. They are apparently rare related to diagnosing periprosthetic infections but have severe consequences if used to guide treatment. Even occasional false-positive Gram stains should prompt review of laboratory methods. Our observations implicate dead bacteria in microbiologic reagents as potential sources of false-positive Gram

  14. Microbial culturomics to isolate halophilic bacteria from table salt: genome sequence and description of the moderately halophilic bacterium Bacillus salis sp. nov.

    Science.gov (United States)

    Seck, E H; Diop, A; Armstrong, N; Delerce, J; Fournier, P-E; Raoult, D; Khelaifia, S

    2018-05-01

    Bacillus salis strain ES3 T (= CSUR P1478 = DSM 100598) is the type strain of B. salis sp. nov. It is an aerobic, Gram-positive, moderately halophilic, motile and spore-forming bacterium. It was isolated from commercial table salt as part of a broad culturomics study aiming to maximize the culture conditions for the in-depth exploration of halophilic bacteria in salty food. Here we describe the phenotypic characteristics of this isolate, its complete genome sequence and annotation, together with a comparison with closely related bacteria. Phylogenetic analysis based on 16S rRNA gene sequences indicated 97.5% similarity with Bacillus aquimaris, the closest species. The 8 329 771 bp long genome (one chromosome, no plasmids) exhibits a G+C content of 39.19%. It is composed of 18 scaffolds with 29 contigs. Of the 8303 predicted genes, 8109 were protein-coding genes and 194 were RNAs. A total of 5778 genes (71.25%) were assigned a putative function.

  15. Detection and Antibiotic Susceptibility Pattern of Biofilm Producing Gram Positive and Gram Negative Bacteria Isolated From a Tertiary Care Hospital of Pakistan

    Directory of Open Access Journals (Sweden)

    Iqbal, M.

    2011-01-01

    Full Text Available Microorganisms adhere to non-living material or living tissue, and form biofilms made up of extracellular polymers/slime. Biofilm-associated microorganisms behave differently from free-floating bacteria with respect to growth rates and ability to resist antimicrobial treatments and therefore pose a public health problem. The objective of this study is to detect the prevalence of biofilm producers among Gram positive and Gram negative bacteria isolated from clinical specimens, and to study their antimicrobial susceptibility pattern. The study was carried out from October 2009 to March 2010, at the Department of Microbiology, Army Medical College/ National University of Sciences and Technology (NUST, Rawalpindi, Pakistan. Clinical specimens were received from various wards of a tertiary care hospital. These were dealt by standard microbiological procedures. Gram positive and Gram negative bacteria isolated were subjected to biofilm detection by congo red agar method (CRA. Antimicrobial susceptibility testing of those isolates, which showed positive results (slime production, was done according to the Kirby-Bauer disc diffusion technique. A total of 150 isolates were tested for the production of biofilm/slime. Among them, 81 isolates showed positive results. From these 81, 51 were Gram positive and 30 were Gram negative. All the 81(54% slime producers showed reduced susceptibility to majority of antibiotics. Bacterial biofilms are an important virulence factor associated with chronic nosocomial infection. Detection of biofilm forming organisms can help in appropriate antibiotic choice.

  16. Sediminibacillus massiliensis sp. nov., a moderately halophilic, Gram-positive bacterium isolated from a stool sample of a young Senegalese man.

    Science.gov (United States)

    Senghor, Bruno; Bassène, Hubert; Khelaifia, Saber; Robert, Catherine; Fournier, Pierre-Edouard; Ruimy, Raymond; Sokhna, Cheikh; Raoult, Didier; Lagier, Jean-Christophe

    2018-07-01

    A Gram-positive, moderately halophilic bacterium, referred to as strain Marseille-P3518 T , was isolated from a stool sample with 2% NaCl concentration from a healthy 15-year-old male living in Dielmo, a village in Senegal. Cells are aerobic, rod-shaped and motile and display endospore formation. Strain Marseille-P3518 T can grow in a medium with 0-20% (w/v) sodium chloride (optimally at 5-7.5% w/v). The major fatty acids were 12-methyl-tetradecanoic acid (45.8%), 13-methyl-tetradecanoic acid (26.9%) and 12-methyl-tridecanoic acid (12.8%). The genome is 4,347,479 bp long with 42.1% G+C content. It contains 4282 protein-coding and 107 RNA genes. Phylogenetic analysis based on 16S rRNA gene sequence comparisons showed that strain Marseille-P3518 T is a member of the Bacillaceae family and is closely related to Sediminibacillus albus (97.4% gene sequence similarity). Strain Marseille-P3518 T was clearly differentiated from its phylogenetic neighbors on the basis of phenotypic and genotypic features. Strain Marseille-P3518 T is, therefore, considered to be a novel representative of the genus Sediminibacillus, for which the name Sediminibacillus massiliensis sp. nov. is proposed, and the type strain is Marseille-P3518 T (CSUR P3518T, DSM69894).

  17. A Disulfide Bond-forming Machine Is Linked to the Sortase-mediated Pilus Assembly Pathway in the Gram-positive Bacterium Actinomyces oris*

    Science.gov (United States)

    Reardon-Robinson, Melissa E.; Osipiuk, Jerzy; Chang, Chungyu; Wu, Chenggang; Jooya, Neda; Joachimiak, Andrzej; Das, Asis; Ton-That, Hung

    2015-01-01

    Export of cell surface pilins in Gram-positive bacteria likely occurs by the translocation of unfolded precursor polypeptides; however, how the unfolded pilins gain their native conformation is presently unknown. Here, we present physiological studies to demonstrate that the FimA pilin of Actinomyces oris contains two disulfide bonds. Alanine substitution of cysteine residues forming the C-terminal disulfide bridge abrogates pilus assembly, in turn eliminating biofilm formation and polymicrobial interaction. Transposon mutagenesis of A. oris yielded a mutant defective in adherence to Streptococcus oralis, and revealed the essential role of a vitamin K epoxide reductase (VKOR) gene in pilus assembly. Targeted deletion of vkor results in the same defects, which are rescued by ectopic expression of VKOR, but not a mutant containing an alanine substitution in its conserved CXXC motif. Depletion of mdbA, which encodes a membrane-bound thiol-disulfide oxidoreductase, abrogates pilus assembly and alters cell morphology. Remarkably, overexpression of MdbA or a counterpart from Corynebacterium diphtheriae, rescues the Δvkor mutant. By alkylation assays, we demonstrate that VKOR is required for MdbA reoxidation. Furthermore, crystallographic studies reveal that A. oris MdbA harbors a thioredoxin-like fold with the conserved CXXC active site. Consistently, each MdbA enzyme catalyzes proper disulfide bond formation within FimA in vitro that requires the catalytic CXXC motif. Because the majority of signal peptide-containing proteins encoded by A. oris possess multiple Cys residues, we propose that MdbA and VKOR constitute a major folding machine for the secretome of this organism. This oxidative protein folding pathway may be a common feature in Actinobacteria. PMID:26170452

  18. A Disulfide Bond-forming Machine Is Linked to the Sortase-mediated Pilus Assembly Pathway in the Gram-positive Bacterium Actinomyces oris.

    Science.gov (United States)

    Reardon-Robinson, Melissa E; Osipiuk, Jerzy; Chang, Chungyu; Wu, Chenggang; Jooya, Neda; Joachimiak, Andrzej; Das, Asis; Ton-That, Hung

    2015-08-28

    Export of cell surface pilins in Gram-positive bacteria likely occurs by the translocation of unfolded precursor polypeptides; however, how the unfolded pilins gain their native conformation is presently unknown. Here, we present physiological studies to demonstrate that the FimA pilin of Actinomyces oris contains two disulfide bonds. Alanine substitution of cysteine residues forming the C-terminal disulfide bridge abrogates pilus assembly, in turn eliminating biofilm formation and polymicrobial interaction. Transposon mutagenesis of A. oris yielded a mutant defective in adherence to Streptococcus oralis, and revealed the essential role of a vitamin K epoxide reductase (VKOR) gene in pilus assembly. Targeted deletion of vkor results in the same defects, which are rescued by ectopic expression of VKOR, but not a mutant containing an alanine substitution in its conserved CXXC motif. Depletion of mdbA, which encodes a membrane-bound thiol-disulfide oxidoreductase, abrogates pilus assembly and alters cell morphology. Remarkably, overexpression of MdbA or a counterpart from Corynebacterium diphtheriae, rescues the Δvkor mutant. By alkylation assays, we demonstrate that VKOR is required for MdbA reoxidation. Furthermore, crystallographic studies reveal that A. oris MdbA harbors a thioredoxin-like fold with the conserved CXXC active site. Consistently, each MdbA enzyme catalyzes proper disulfide bond formation within FimA in vitro that requires the catalytic CXXC motif. Because the majority of signal peptide-containing proteins encoded by A. oris possess multiple Cys residues, we propose that MdbA and VKOR constitute a major folding machine for the secretome of this organism. This oxidative protein folding pathway may be a common feature in Actinobacteria. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. The Causes of Post-Operative Meningitis: The Comparison Of Gram-Negative and Gram-Positive Pathogens.

    Science.gov (United States)

    Kurtaran, Behice; Kuscu, Ferit; Ulu, Aslihan; Inal, Ayse Seza; Komur, Suheyla; Kibar, Filiz; Cetinalp, Nuri Eralp; Ozsoy, Kerem Mazhar; Arslan, Yusuf Kemal; Aksu, Hasan Salih; Tasova, Yesim

    2017-06-20

    In this study, we aim to determine the microbiological etiology in critically ill neurosurgical patients with nosocomial meningitis (NM) and show the impact of Gram-negative rods and differences of patient's characteristics, clinical and prognostic measures between Gram-negative and Gram-positive meningitis. In this prospective, one center study we reviewed all adult patients hospitalized during a 12-year period and identified pathogens isolated from post-neurosurgical cases of NM. Demographic, clinical, and treatment characteristics were noted from the medical records. Of the 134 bacterial NM patients, 78 were male and 56 were female, with a mean age of 46±15.9 and median age of 50 (18-80) years. 141 strains isolated; 82 (58.2%) were Gram negative, 59 (41.8%) were Gram positive. Most common isolated microorganism was Acinetobacter baumannii (%34.8). In comparison of mortality data shows that the patients who have meningitis with Gram-negative pathogens have higher mortality than with Gram positives (p=0.034). The duration between surgery and meningitis was shorter in Gram negative meningitis cases compared to others (p=0.045) but the duration between the diagnosis and death was shorter in Gram-positive meningitis cases compared to Gram negatives (p= 0.017). CSF protein and lactate level were higher and glucose level was lower in cases of NM with Gram negatives (p value were respectively, 0.022, 0.039 and 0.049). As conclusions; in NM, Gram-negative pathogens were seen more frequently; A.baumanni was the predominant pathogen; and NM caused by Gram negatives had worse clinical and laboratory characteristic and prognostic outcome than Gram positives.

  20. Polymers for binding of the gram-positive oral pathogen Streptococcus mutans

    Science.gov (United States)

    Magennis, Eugene P.; Francini, Nora; Mastrotto, Francesca; Catania, Rosa; Redhead, Martin; Fernandez-Trillo, Francisco; Bradshaw, David; Churchley, David; Winzer, Klaus; Alexander, Cameron

    2017-01-01

    Streptococcus mutans is the most significant pathogenic bacterium implicated in the formation of dental caries and, both directly and indirectly, has been associated with severe conditions such as multiple sclerosis, cerebrovascular and peripheral artery disease. Polymers able to selectively bind S. mutans and/or inhibit its adhesion to oral tissue in a non-lethal manner would offer possibilities for addressing pathogenicity without selecting for populations resistant against bactericidal agents. In the present work two libraries of 2-(dimethylamino)ethyl methacrylate (pDMAEMA)-based polymers were synthesized with various proportions of either N,N,N-trimethylethanaminium cationic- or sulfobetaine zwitterionic groups. These copolymers where initially tested as potential macromolecular ligands for S. mutans NCTC 10449, whilst Escherichia coli MG1655 was used as Gram-negative control bacteria. pDMAEMA-derived materials with high proportions of zwitterionic repeating units were found to be selective for S. mutans, in both isolated and S. mutans–E. coli mixed bacterial cultures. Fully sulfobetainized pDMAEMA was subsequently found to bind/cluster preferentially Gram-positive S. mutans and S. aureus compared to Gram negative E. coli and V. harveyi. A key initial stage of S. mutans pathogenesis involves a lectin-mediated adhesion to the tooth surface, thus the range of potential macromolecular ligands was further expanded by investigating two glycopolymers bearing α-mannopyranoside and β-galactopyranoside pendant units. Results with these polymers indicated that preferential binding to either S. mutans or E. coli can be obtained by modulating the glycosylation pattern of the chosen multivalent ligands without incurring unacceptable cytotoxicity in a model gastrointestinal cell line. Overall, our results allowed to identify a structure–property relationship for the potential antimicrobial polymers investigated, and suggest that preferential binding to Gram-positive S

  1. Physiological Ecology of Clostridium glycolicum RD-1, an Aerotolerant Acetogen Isolated from Sea Grass Roots

    OpenAIRE

    Küsel, Kirsten; Karnholz, Arno; Trinkwalter, Tanja; Devereux, Richard; Acker, Georg; Drake, Harold L.

    2001-01-01

    An anaerobic, H2-utilizing bacterium, strain RD-1, was isolated from the highest growth-positive dilution series of a root homogenate prepared from the sea grass Halodule wrightii. Cells of RD-1 were gram-positive, spore-forming, motile rods that were linked by connecting filaments. Acetate was produced in stoichiometries indicative of an acetyl coenzyme A (acetyl-CoA) pathway-dependent metabolism when RD-1 utilized H2-CO2, formate, lactate, or pyruvate. Growth on sugars or ethylene glycol yi...

  2. Effects of Phosphorelay Perturbations on Architecture, Sporulation, and Spore Resistance in Biofilms of Bacillus subtilis

    NARCIS (Netherlands)

    Veening, JW; Kuipers, OP; Brul, S; Hellingwerf, KJ; Kort, R

    The spore-forming bacterium Bacillus subtilis is able to form highly organized multicellular communities called biofilms. This coordinated bacterial behavior is often lost in domesticated or laboratory strains as a result of planktonic growth in rich media for many generations. However, we show here

  3. Using Thermal Inactivation Kinetics to Calculate the Probability of Extreme Spore Longevity: Implications for Paleomicrobiology and Lithopanspermia

    Science.gov (United States)

    Nicholson, Wayne L.

    2003-12-01

    Thermal inactivation kinetics with extrapolation were used to model the survival probabilities of spores of various Bacillus species over time periods of millions of years at the historical ambient temperatures (25-40 °) encountered within the 250 million-year-old Salado formation, from which the putative ancient spore-forming bacterium Salibacillus marismortui strain 2-9-3 was recovered. The model indicated extremely low-to-moderate survival probabilities for spores of mesophiles, but surprisingly high survival probabilities for thermophilic spores. The significance of the results are discussed in terms of the survival probabilities of (i) terrestrial spores in ancient geologic samples and (ii) spores transported between planets within impact ejecta.

  4. Identification of a Novel Lipoprotein Regulator of Clostridium difficile Spore Germination.

    Directory of Open Access Journals (Sweden)

    Kelly A Fimlaid

    2015-10-01

    Full Text Available Clostridium difficile is a Gram-positive spore-forming pathogen and a leading cause of nosocomial diarrhea. C. difficile infections are transmitted when ingested spores germinate in the gastrointestinal tract and transform into vegetative cells. Germination begins when the germinant receptor CspC detects bile salts in the gut. CspC is a subtilisin-like serine pseudoprotease that activates the related CspB serine protease through an unknown mechanism. Activated CspB cleaves the pro-SleC zymogen, which allows the activated SleC cortex hydrolase to degrade the protective cortex layer. While these regulators are essential for C. difficile spores to outgrow and form toxin-secreting vegetative cells, the mechanisms controlling their function have only been partially characterized. In this study, we identify the lipoprotein GerS as a novel regulator of C. difficile spore germination using targeted mutagenesis. A gerS mutant has a severe germination defect and fails to degrade cortex even though it processes SleC at wildtype levels. Using complementation analyses, we demonstrate that GerS secretion, but not lipidation, is necessary for GerS to activate SleC. Importantly, loss of GerS attenuates the virulence of C. difficile in a hamster model of infection. Since GerS appears to be conserved exclusively in related Peptostreptococcaeace family members, our results contribute to a growing body of work indicating that C. difficile has evolved distinct mechanisms for controlling the exit from dormancy relative to B. subtilis and other spore-forming organisms.

  5. Mid-infrared spectroscopic assessment of nanotoxicity in gram-negative vs. gram-positive bacteria.

    Science.gov (United States)

    Heys, Kelly A; Riding, Matthew J; Strong, Rebecca J; Shore, Richard F; Pereira, M Glória; Jones, Kevin C; Semple, Kirk T; Martin, Francis L

    2014-03-07

    Nanoparticles appear to induce toxic effects through a variety of mechanisms including generation of reactive oxygen species (ROS), physical contact with the cell membrane and indirect catalysis due to remnants from manufacture. The development and subsequent increasing usage of nanomaterials has highlighted a growing need to characterize and assess the toxicity of nanoparticles, particularly those that may have detrimental health effects such as carbon-based nanomaterials (CBNs). Due to interactions of nanoparticles with some reagents, many traditional toxicity tests are unsuitable for use with CBNs. Infrared (IR) spectroscopy is a non-destructive, high throughput technique, which is unhindered by such problems. We explored the application of IR spectroscopy to investigate the effects of CBNs on Gram-negative (Pseudomonas fluorescens) and Gram-positive (Mycobacterium vanbaalenii PYR-1) bacteria. Two types of IR spectroscopy were compared: attenuated total reflection Fourier-transform infrared (ATR-FTIR) and synchrotron radiation-based FTIR (SR-FTIR) spectroscopy. This showed that Gram-positive and Gram-negative bacteria exhibit differing alterations when exposed to CBNs. Gram-positive bacteria appear more resistant to these agents and this may be due to the protection afforded by their more sturdy cell wall. Markers of exposure also vary according to Gram status; Amide II was consistently altered in Gram-negative bacteria and carbohydrate altered in Gram-positive bacteria. ATR-FTIR and SR-FTIR spectroscopy could both be applied to extract biochemical alterations induced by each CBN that were consistent across the two bacterial species; these may represent potential biomarkers of nanoparticle-induced alterations. Vibrational spectroscopy approaches may provide a novel means of fingerprinting the effects of CBNs in target cells.

  6. Thusin, a novel two-component lantibiotic with potent antimicrobial activity against several Gram-positive pathogens

    Directory of Open Access Journals (Sweden)

    Bingyue Xin

    2016-07-01

    Full Text Available Due to the rapidly increasing prevalence of multidrug-resistant bacterial strains, the need for new antimicrobial drugs to treat infections has become urgent. Bacteriocins, which are antimicrobial peptides of bacterial origin, are considered potential alternatives to conventional antibiotics and have attracted widespread attention in recent years. Among these bacteriocins, lantibiotics, especially two-component lantibiotics, exhibit potent antimicrobial activity against some clinically relevant Gram-positive pathogens and have potential applications in the pharmaceutical industry. In this study, we characterized a novel two-component lantibiotic termed thusin that consists of Thsα, Thsβ and Thsβ' (mutation of Thsβ, A14G and that was isolated from a B. thuringiensis strain BGSC 4BT1. Thsα and Thsβ (or Thsβ' exhibit optimal antimicrobial activity at a 1:1 ratio and act sequentially to affect target cells, and they are all highly thermostable (100°C for 30 min and pH tolerant (pH 2.0 to 9.0. Thusin shows remarkable efficacy against all tested Gram-positive bacteria and greater activities than two known lantibiotics thuricin 4A-4 and ticin A4, and one antibiotic vancomycin against various bacterial pathogens (Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus (MRSA, Staphylococcus sciuri, Enterococcus faecalis, and Streptococcus pneumoniae. Moreover, thusin is also able to inhibit the outgrowth of Bacillus cereus spores. The potent antimicrobial activity of thusin against some Gram-positive pathogens indicates that it has potential for the development of new drugs.

  7. Gram positive and Gram negative bacteria differ in their sensitivity to cold plasma

    Science.gov (United States)

    Mai-Prochnow, Anne; Clauson, Maryse; Hong, Jungmi; Murphy, Anthony B.

    2016-12-01

    Cold atmospheric-pressure plasma (CAP) is a relatively new method being investigated for antimicrobial activity. However, the exact mode of action is still being explored. Here we report that CAP efficacy is directly correlated to bacterial cell wall thickness in several species. Biofilms of Gram positive Bacillus subtilis, possessing a 55.4 nm cell wall, showed the highest resistance to CAP, with less than one log10 reduction after 10 min treatment. In contrast, biofilms of Gram negative Pseudomonas aeruginosa, possessing only a 2.4 nm cell wall, were almost completely eradicated using the same treatment conditions. Planktonic cultures of Gram negative Pseudomonas libanensis also had a higher log10 reduction than Gram positive Staphylococcus epidermidis. Mixed species biofilms of P. aeruginosa and S. epidermidis showed a similar trend of Gram positive bacteria being more resistant to CAP treatment. However, when grown in co-culture, Gram negative P. aeruginosa was more resistant to CAP overall than as a mono-species biofilm. Emission spectra indicated OH and O, capable of structural cell wall bond breakage, were present in the plasma. This study indicates that cell wall thickness correlates with CAP inactivation times of bacteria, but cell membranes and biofilm matrix are also likely to play a role.

  8. Type I and Type II mechanisms of antimicrobial photodynamic therapy: an in vitro study on gram-negative and gram-positive bacteria.

    Science.gov (United States)

    Huang, Liyi; Xuan, Yi; Koide, Yuichiro; Zhiyentayev, Timur; Tanaka, Masamitsu; Hamblin, Michael R

    2012-08-01

    Antimicrobial photodynamic therapy (APDT) employs a non-toxic photosensitizer (PS) and visible light, which in the presence of oxygen produce reactive oxygen species (ROS), such as singlet oxygen ((1) O(2), produced via Type II mechanism) and hydroxyl radical (HO(.), produced via Type I mechanism). This study examined the relative contributions of (1) O(2) and HO(.) to APDT killing of Gram-positive and Gram-negative bacteria. Fluorescence probes, 3'-(p-hydroxyphenyl)-fluorescein (HPF) and singlet oxygen sensor green reagent (SOSG) were used to determine HO(.) and (1) O(2) produced by illumination of two PS: tris-cationic-buckminsterfullerene (BB6) and a conjugate between polyethylenimine and chlorin(e6) (PEI-ce6). Dimethylthiourea is a HO(.) scavenger, while sodium azide (NaN(3)) is a quencher of (1) O(2). Both APDT and killing by Fenton reaction (chemical generation of HO(.)) were carried out on Gram-positive bacteria (Staphylococcus aureus and Enterococcus faecalis) and Gram-negative bacteria (Escherichia coli, Proteus mirabilis, and Pseudomonas aeruginosa). Conjugate PEI-ce6 mainly produced (1) O(2) (quenched by NaN(3)), while BB6 produced HO(.) in addition to (1) O(2) when NaN(3) potentiated probe activation. NaN(3) also potentiated HPF activation by Fenton reagent. All bacteria were killed by Fenton reagent but Gram-positive bacteria needed a higher concentration than Gram-negatives. NaN(3) potentiated Fenton-mediated killing of all bacteria. The ratio of APDT killing between Gram-positive and Gram-negative bacteria was 2 or 4:1 for BB6 and 25:1 for conjugate PEI-ce6. There was a NaN(3) dose-dependent inhibition of APDT killing using both PEI-ce6 and BB6 against Gram-negative bacteria while NaN(3) almost failed to inhibit killing of Gram-positive bacteria. Azidyl radicals may be formed from NaN(3) and HO(.). It may be that Gram-negative bacteria are more susceptible to HO(.) while Gram-positive bacteria are more susceptible to (1) O(2). The differences in Na

  9. Distribution of multi-resistant Gram-negative versus Gram-positive bacteria in the hospital inanimate environment.

    Science.gov (United States)

    Lemmen, S W; Häfner, H; Zolldann, D; Stanzel, S; Lütticken, R

    2004-03-01

    We prospectively studied the difference in detection rates of multi-resistant Gram-positive and multi-resistant Gram-negative bacteria in the inanimate environment of patients harbouring these organisms. Up to 20 different locations around 190 patients were surveyed. Fifty-four patients were infected or colonized with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant enterococci (VRE) and 136 with multi-resistant Gram-negative bacteria. The environmental detection rate for MRSA or VRE was 24.7% (174/705 samples) compared with 4.9% (89/1827 samples) for multi-resistant Gram-negative bacteria (PGram-positive bacteria were isolated more frequently than Gram-negatives from the hands of patients (PGram-positive and Gram-negative isolates. Our results suggest that the inanimate environment serves as a secondary source for MRSA and VRE, but less so for Gram-negative bacteria. Thus, strict contact isolation in a single room with complete barrier precautions is recommended for MRSA or VRE; however, for multi-resistant Gram-negative bacteria, contact isolation with barrier precautions for close contact but without a single room seems sufficient. This benefits not only the patients, but also the hospital by removing some of the strain placed on already over-stretched resources.

  10. Isolation of Clostridium difficile and Detection of A and B Toxins Encoding Genes

    OpenAIRE

    Abbas Ali Imani Fooladi; Sadegh Rahmati; Jalil Falah Mehr Abadi; Raheleh Halabian; Hamid Sedighian; Mohammad Javad Soltanpour; Mohsen Rahimi

    2014-01-01

    Background: Clostridium difficile is the most important anaerobic, gram positive, spore forming bacillus which is known as a prevalent factor leading to antibiotic associated diarrheas and is the causative agent of pseudomembrane colitis. The role of this bacterium along with the over use of antibiotics have been proved to result in colitis. The major virulence factors of these bacteria are the A and B toxins. Objectives: The purpose of this study was to isolate C. difficile from sto...

  11. Evaluation of Inhibitory and Lethal Effects of Aqueous, Ethanolic and Hydroalcoholic Extracts of Aerial Parts of Salvia chorassanica against Some Gram-negative and Gram-positive Bacteria in Vitro

    Directory of Open Access Journals (Sweden)

    Azam Mehraban

    2016-05-01

    Full Text Available Abstract Background and Objectives: Development of bacterial resistance to antibiotics has led to an increased tendency to development of new more effective and non-toxic antimicrobial compounds. In this study, the inhibitory and lethal effects of aqueous, ethanolic, and hydroalcoholic extracts of aerial parts of Salvia chorassanica were evaluated against Listeria monocytogenes, Bacillus cereus, Salmonella typhi, and Escherichia coli O:157. Methods: In this study, Kirby–Bauer disk diffusion method was used to evaluate antimicrobial activity. In this method, bacteria were cultivated as grass culture in Mueller Hinton Agar (MHA media. To determine the minimum inhibitory concentration and minimum bactericidal concentration, micro-dilution method with ELISA and addition of phenyl tetrazolium chloride reagent, were used. Data were analyzed using one-way ANOVA and Duncan’s test at the significance level of p<0.05. Results: The highest diameter of inhibition in agar diffusion method was related to hydroalcoholic extract of aerial parts of Salvia chorassanica against Gram-positive bacteria Bacillus cereus. The amount of calculated MIC of hydro-alcoholic extract for Gram-positive bacteria was 30mg/ml. This amount was the lowest among other measured MIC. Conclusion: Based on the results of this study, Gram-negative bacteria showed more resistance to different extracts of aerial parts of Salvia chorassanica as compared to Gram-positive bacteria, so that Salmonella typhi was found to be the most resistant bacterium among the tested bacteria.

  12. An optimized staining technique for the detection of Gram positive and Gram negative bacteria within tissue.

    Science.gov (United States)

    Becerra, Sandra C; Roy, Daniel C; Sanchez, Carlos J; Christy, Robert J; Burmeister, David M

    2016-04-12

    Bacterial infections are a common clinical problem in both acute and chronic wounds. With growing concerns over antibiotic resistance, treatment of bacterial infections should only occur after positive diagnosis. Currently, diagnosis is delayed due to lengthy culturing methods which may also fail to identify the presence of bacteria. While newer costly bacterial identification methods are being explored, a simple and inexpensive diagnostic tool would aid in immediate and accurate treatments for bacterial infections. Histologically, hematoxylin and eosin (H&E) and Gram stains have been employed, but are far from optimal when analyzing tissue samples due to non-specific staining. The goal of the current study was to develop a modification of the Gram stain that enhances the contrast between bacteria and host tissue. A modified Gram stain was developed and tested as an alternative to Gram stain that improves the contrast between Gram positive bacteria, Gram negative bacteria and host tissue. Initially, clinically relevant strains of Pseudomonas aeruginosa and Staphylococcus aureus were visualized in vitro and in biopsies of infected, porcine burns using routine Gram stain, and immunohistochemistry techniques involving bacterial strain-specific fluorescent antibodies as validation tools. H&E and Gram stain of serial biopsy sections were then compared to a modification of the Gram stain incorporating a counterstain that highlights collagen found in tissue. The modified Gram stain clearly identified both Gram positive and Gram negative bacteria, and when compared to H&E or Gram stain alone provided excellent contrast between bacteria and non-viable burn eschar. Moreover, when applied to surgical biopsies from patients that underwent burn debridement this technique was able to clearly detect bacterial morphology within host tissue. We describe a modification of the Gram stain that provides improved contrast of Gram positive and Gram negative microorganisms within host

  13. Microbial culturomics to isolate halophilic bacteria from table salt: genome sequence and description of the moderately halophilic bacterium Bacillus salis sp. nov.

    Directory of Open Access Journals (Sweden)

    E.H. Seck

    2018-05-01

    Full Text Available Bacillus salis strain ES3T (= CSUR P1478 = DSM 100598 is the type strain of B. salis sp. nov. It is an aerobic, Gram-positive, moderately halophilic, motile and spore-forming bacterium. It was isolated from commercial table salt as part of a broad culturomics study aiming to maximize the culture conditions for the in-depth exploration of halophilic bacteria in salty food. Here we describe the phenotypic characteristics of this isolate, its complete genome sequence and annotation, together with a comparison with closely related bacteria. Phylogenetic analysis based on 16S rRNA gene sequences indicated 97.5% similarity with Bacillus aquimaris, the closest species. The 8 329 771 bp long genome (one chromosome, no plasmids exhibits a G+C content of 39.19%. It is composed of 18 scaffolds with 29 contigs. Of the 8303 predicted genes, 8109 were protein-coding genes and 194 were RNAs. A total of 5778 genes (71.25% were assigned a putative function. Keywords: Bacillus salis, culturomics, genome, halophilic bacteria, human gut, taxonogenomics

  14. Raman Spectroscopy of Xylitol Uptake and Metabolism in Gram-Positive and Gram-Negative Bacteria▿

    Science.gov (United States)

    Palchaudhuri, Sunil; Rehse, Steven J.; Hamasha, Khozima; Syed, Talha; Kurtovic, Eldar; Kurtovic, Emir; Stenger, James

    2011-01-01

    Visible-wavelength Raman spectroscopy was used to investigate the uptake and metabolism of the five-carbon sugar alcohol xylitol by Gram-positive viridans group streptococcus and the two extensively used strains of Gram-negative Escherichia coli, E. coli C and E. coli K-12. E. coli C, but not E. coli K-12, contains a complete xylitol operon, and the viridans group streptococcus contains an incomplete xylitol operon used to metabolize the xylitol. Raman spectra from xylitol-exposed viridans group streptococcus exhibited significant changes that persisted even in progeny grown from the xylitol-exposed mother cells in a xylitol-free medium for 24 h. This behavior was not observed in the E. coli K-12. In both viridans group streptococcus and the E. coli C derivative HF4714, the metabolic intermediates are stably formed to create an anomaly in bacterial normal survival. The uptake of xylitol by Gram-positive and Gram-negative pathogens occurs even in the presence of other high-calorie sugars, and its stable integration within the bacterial cell wall may discontinue bacterial multiplication. This could be a contributing factor for the known efficacy of xylitol when taken as a prophylactic measure to prevent or reduce occurrences of persistent infection. Specifically, these bacteria are causative agents for several important diseases of children such as pneumonia, otitis media, meningitis, and dental caries. If properly explored, such an inexpensive and harmless sugar-alcohol, alone or used in conjunction with fluoride, would pave the way to an alternative preventive therapy for these childhood diseases when the causative pathogens have become resistant to modern medicines such as antibiotics and vaccine immunotherapy. PMID:21037297

  15. The Toll pathway underlies host sexual dimorphism in resistance to both Gram-negative and Gram-positive bacteria in mated Drosophila.

    Science.gov (United States)

    Duneau, David F; Kondolf, Hannah C; Im, Joo Hyun; Ortiz, Gerardo A; Chow, Christopher; Fox, Michael A; Eugénio, Ana T; Revah, J; Buchon, Nicolas; Lazzaro, Brian P

    2017-12-21

    Host sexual dimorphism is being increasingly recognized to generate strong differences in the outcome of infectious disease, but the mechanisms underlying immunological differences between males and females remain poorly characterized. Here, we used Drosophila melanogaster to assess and dissect sexual dimorphism in the innate response to systemic bacterial infection. We demonstrated sexual dimorphism in susceptibility to infection by a broad spectrum of Gram-positive and Gram-negative bacteria. We found that both virgin and mated females are more susceptible than mated males to most, but not all, infections. We investigated in more detail the lower resistance of females to infection with Providencia rettgeri, a Gram-negative bacterium that naturally infects D. melanogaster. We found that females have a higher number of phagocytes than males and that ablation of hemocytes does not eliminate the dimorphism in resistance to P. rettgeri, so the observed dimorphism does not stem from differences in the cellular response. The Imd pathway is critical for the production of antimicrobial peptides in response to Gram-negative bacteria, but mutants for Imd signaling continued to exhibit dimorphism even though both sexes showed strongly reduced resistance. Instead, we found that the Toll pathway is responsible for the dimorphism in resistance. The Toll pathway is dimorphic in genome-wide constitutive gene expression and in induced response to infection. Toll signaling is dimorphic in both constitutive signaling and in induced activation in response to P. rettgeri infection. The dimorphism in pathway activation can be specifically attributed to Persephone-mediated immune stimulation, by which the Toll pathway is triggered in response to pathogen-derived virulence factors. We additionally found that, in absence of Toll signaling, males become more susceptible than females to the Gram-positive Enterococcus faecalis. This reversal in susceptibility between male and female Toll

  16. Evolution of exploitative interactions during diversification in Bacillus subtilis biofilms

    DEFF Research Database (Denmark)

    Dragoš, Anna; Lakshmanan, Nivedha; Martin, Marivic

    2018-01-01

    variants. These variants can settle in alternative biofilm niches and develop new types of interactions that greatly influence population productivity. Here, we explore the evolutionary diversification of pellicle biofilms of the Gram positive, spore-forming bacterium Bacillus subtilis. We discover that......-similarly to other species-B. subtilis diversifies into distinct colony variants. These variants dramatically differ in biofilm formation abilities and expression of biofilm-related genes. In addition, using a quantitative approach, we reveal striking differences in surface complexity and hydrophobicity...

  17. Nioella nitratireducens gen. nov., sp. nov., a novel member of the family Rhodobacteraceae isolated from Azorean Island

    Digital Repository Service at National Institute of Oceanography (India)

    Rajasabapathy, R.; Mohandass, C; Yoon, J; Dastager, S.G.; Liu, Q.; Khieu, T.-N.; Son, C; Li, W.-J; Colaco, A.

    A novel Gram-negative, non-spore forming, rod-shaped aerobic bacterium, designated SSW136T, was isolated from a surface seawater sample collected at Espalamaca (in Faial Island), Azores. Growth was found to occur from 10 to 37 °C, pH 6...

  18. Organo-Selenium Coatings Inhibit Gram-Negative and Gram-Positive Bacterial Attachment to Ophthalmic Scleral Buckle Material.

    Science.gov (United States)

    Tran, Phat; Arnett, Avery; Jarvis, Courtney; Mosley, Thomas; Tran, Khien; Hanes, Rob; Webster, Dan; Mitchell, Kelly; Dominguez, Leo; Hamood, Abdul; Reid, Ted W

    2017-09-01

    Biofilm formation is a problem for solid and sponge-type scleral buckles. This can lead to complications that require removal of the buckle, and result in vision loss due to related ocular morbidity, primarily infection, or recurrent retinal detachment. We investigate the ability of a covalent organo-selenium coating to inhibit biofilm formation on a scleral buckle. Sponge and solid Labtican brand scleral buckles were coated with organo-selenium coupled to a silyation reagent. Staphylococcus aureus biofilm formation was monitored by a standard colony-forming unit assay and the confocal laser scanning microscopy, while Pseudomonas aeruginosa biofilm formation was examined by scanning electron microscopy. Stability studies were done, by soaking in phosphate buffer saline (PBS) at room temperature for 2 months. Toxicity against human corneal epithelial cell was examined by growing the cells in the presence of organo-selenium-coated scleral buckles. The organo-selenium coating inhibited biofilm formation by gram-negative and gram-positive bacteria. The buckle coatings also were shown to be fully active after soaking in PBS for 2 months. The organo-selenium coatings had no effect on the viability of human corneal epithelial cells. Organo-selenium can be used to covalently coat a scleral buckle, which is stable and inhibits biofilm formation for gram-negative and gram-positive bacteria. The organo-selenium buckle coating was stable and nontoxic to cell culture. This technology provides a means to inhibit bacterial attachment to devices attached to the eye, without damage to ocular cells.

  19. Glass bead transformation method for gram-positive bacteria

    OpenAIRE

    Rattanachaikunsopon, Pongsak; Phumkhachorn, Parichat

    2009-01-01

    A simple, inexpensive and reproducible transformation method was developed for Gram-positive bacteria. It was based on agitation of bacterial protoplasts with glass beads in the presence of DNA and polyethylene glycol. By using this method, introduction of pGK12 into protoplasts of several strains of Gram-positive bacteria was achieved.

  20. Comparative activity of ceftobiprole against Gram-positive and Gram-negative isolates from Europe and the Middle East: the CLASS study.

    Science.gov (United States)

    Rossolini, Gian M; Dryden, Matthew S; Kozlov, Roman S; Quintana, Alvaro; Flamm, Robert K; Läuffer, Jörg M; Lee, Emma; Morrissey, Ian; CLASS Study Group

    2011-01-01

    to assess the in vitro activity of ceftobiprole and comparators against a recent collection of Gram-positive and Gram-negative pathogens, in order to detect potential changes in susceptibility patterns, and to evaluate the Etest assay for ceftobiprole susceptibility testing. contemporary Gram-positive and Gram-negative isolates (excluding extended-spectrum β-lactamase-producing isolates) from across Europe and the Middle East were collected, and their susceptibility to ceftobiprole, vancomycin, teicoplanin, linezolid, ceftazidime and cefepime was assessed using the Etest method. Quality testing [using Etest and broth microdilution (BMD)] was conducted at a central reference laboratory. some 5041 Gram-positive and 4026 Gram-negative isolates were included. Against Gram-positive isolates overall, ceftobiprole had the lowest MIC50 (0.5 mg/L), compared with 1 mg/L for its comparators (vancomycin, teicoplanin and linezolid). Against methicillin-resistant Staphylococcus aureus, all four agents had a similar MIC90 (2 mg/L), but ceftobiprole had a 4-fold better MIC90 (0.5 mg/L) against methicillin-susceptible strains. Only 38 Gram-positive isolates were confirmed as ceftobiprole resistant. Among Gram-negative strains, 86.9%, 91.7% and 95.2% were susceptible to ceftobiprole, ceftazidime and cefepime, respectively. Pseudomonas aeruginosa was less susceptible to all three antimicrobials than any other Gram-negative pathogen. There was generally good agreement between local Etest results and those obtained at the reference laboratory (for ceftobiprole: 86.8% with Gram-negatives; and 94.7% with Gram-positives), as well as between results obtained by BMD and Etest methods (for ceftobiprole: 98.2% with Gram-negatives; and 98.4% with Gram-positives). ceftobiprole exhibits in vitro activity against a wide range of Gram-positive and Gram-negative pathogens, including multidrug-resistant strains. No changes in its known susceptibility profile were identified.

  1. Prognostic factors and monomicrobial necrotizing fasciitis: gram-positive versus gram-negative pathogens

    Directory of Open Access Journals (Sweden)

    Hsu Wei-Hsiu

    2011-01-01

    Full Text Available Abstract Background Monomicrobial necrotizing fasciitis is rapidly progressive and life-threatening. This study was undertaken to ascertain whether the clinical presentation and outcome for patients with this disease differ for those infected with a gram-positive as compared to gram-negative pathogen. Methods Forty-six patients with monomicrobial necrotizing fasciitis were examined retrospectively from November 2002 to January 2008. All patients received adequate broad-spectrum antibiotic therapy, aggressive resuscitation, prompt radical debridement and adjuvant hyperbaric oxygen therapy. Eleven patients were infected with a gram-positive pathogen (Group 1 and 35 patients with a gram-negative pathogen (Group 2. Results Group 2 was characterized by a higher incidence of hemorrhagic bullae and septic shock, higher APACHE II scores at 24 h post-admission, a higher rate of thrombocytopenia, and a higher prevalence of chronic liver dysfunction. Gouty arthritis was more prevalent in Group 1. For non-survivors, the incidences of chronic liver dysfunction, chronic renal failure and thrombocytopenia were higher in comparison with those for survivors. Lower level of serum albumin was also demonstrated in the non-survivors as compared to those in survivors. Conclusions Pre-existing chronic liver dysfunction, chronic renal failure, thrombocytopenia and hypoalbuminemia, and post-operative dependence on mechanical ventilation represent poor prognostic factors in monomicrobial necrotizing fasciitis. Patients with gram-negative monobacterial necrotizing fasciitis present with more fulminant sepsis.

  2. Protamine-induced permeabilization of cell envelopes of gram-positive and gram-negative bacteria

    DEFF Research Database (Denmark)

    Johansen, Charlotte; Verheul, A.; Gram, Lone

    1997-01-01

    carboxyfluorescein and ATP after 2 to 5 min. Maximum antibacterial activity was reached at alkaline pH and in the absence of divalent cations. The efficient permeabilization of cell envelopes of both gram-positive and gram-negative bacteria suggests that protamine causes a general disruption of the cell envelope...

  3. Clostridium perfringens Sporulation and Sporulation-Associated Toxin Production

    Science.gov (United States)

    Li, Jihong; Paredes-Sabja, Daniel; Sarker, Mahfuzur R.; McClane, Bruce A.

    2015-01-01

    The ability of Clostridium perfringens to form spores plays a key role during the transmission of this Gram-positive bacterium to cause disease. Of particular note, the spores produced by food poisoning strains are often exceptionally resistant to food environment stresses such as heat, cold and preservatives, which likely facilitates their survival in temperature-abused foods. The exceptional resistance properties of spores made by most type A food poisoning strains and some type C foodborne disease strains involves their production of a variant small acid soluble protein-4 that binds more tightly to spore DNA compared to the small acid soluble protein-4 made by most other C. perfringens strains. Sporulation and germination by C. perfringens and Bacillus spp. share both similarities and differences. Finally, sporulation is essential for production of C. perfringens enterotoxin, which is responsible for the symptoms of C. perfringens type A food poisoning, the second most common bacterial foodborne disease in the USA. During this foodborne disease, C. perfringens is ingested with food and then, using sporulation-specific alternate sigma factors, this bacterium sporulates and produces the enterotoxin in the intestines. PMID:27337447

  4. Efforts to identify spore forming bacillus

    Energy Technology Data Exchange (ETDEWEB)

    Zuleiha, M.S.; Hilmy, N. (National Atomic Energy Agency, Jakarta (Indonesia). Pasar Djumat Research Centre)

    1982-04-01

    Efforts to identify 47 species of radioresistant spore forming bacillus sp. isolated from locally produced medical devices have been carried out. The identifications was conducted using 19 kinds of biochemical tests and compared to species to bacillus subtilis W. T.; bacillus pumilus E 601 and bacillus sphaericus Csub(I)A. The results showed that bacillus sp. examined could be divided into 6 groups, i.e. bacillus cereus; bacillus subtilis; bacillus stearothermophylus; bacillus coagulans; bacillus sphaericus and bacillus circulans.

  5. Efforts to identify spore forming bacillus

    International Nuclear Information System (INIS)

    Zuleiha, M.S.; Hilmy, Nazly

    1982-01-01

    Efforts to identify 47 species of radioresistant spore forming bacillus sp. isolated from locally produced medical devices have been carried out. The identifications was conducted using 19 kinds of biochemical tests and compared to species to bacillus subtilis W. T.; bacillus pumilus E 601 and bacillus sphaericus Csub(I)A. The results showed that bacillus sp. examined could be divided into 6 groups, i.e. bacillus cereus; bacillus subtilis; bacillus stearothermophylus; bacillus coagulans; bacillus sphaericus and bacillus circulans. (author)

  6. Thermoanaerobacter mathranii sp. nov., an ethanol-producing, extremely thermophilic anaerobic bacterium from a hot spring in Iceland

    DEFF Research Database (Denmark)

    Larsen, L.; Nielsen, P.; Ahring, B.K.

    1997-01-01

    The extremely thermophilic ethanol-producing strain A3 was isolated from a hot spring in Iceland, The cells were rod-shaped, motile, and had terminal spores: cells from the mid-to-late exponential growth phase stained gram-variable but had a gram-positive cell wall structure when viewed...

  7. Defining a role for Hfq in Gram-positive bacteria

    DEFF Research Database (Denmark)

    Nielsen, Jesper Sejrup; Lei, Lisbeth Kristensen; Ebersbach, Tine

    2010-01-01

    Small trans-encoded RNAs (sRNAs) modulate the translation and decay of mRNAs in bacteria. In Gram-negative species, antisense regulation by trans-encoded sRNAs relies on the Sm-like protein Hfq. In contrast to this, Hfq is dispensable for sRNA-mediated riboregulation in the Gram-positive species......-dependent and -independent mechanisms, thus adding another layer of complexity to sRNA-mediated riboregulation in Gram-positive species....

  8. Roseovarius azorensis sp. nov., isolated from seawater at Espalamaca, Azores

    Digital Repository Service at National Institute of Oceanography (India)

    Rajasabapathy, R.; Mohandass, C; Dastager, S.G.; Liu, Q.; Khieu, T.-N.; Son, C; Li, W.-J; Colaco, A.

    A Gram-negative, motile, non-spore forming, rod shaped aerobic bacterium, designated strain SSW084T, was isolated from a surface seawater sample collected at Espalamaca (38°33`N; 28°39`W), Azores. Growth was found to occur from 15 to 40...

  9. PHYLOGENETIC ANALYSIS AND AUTECOLOGY OF SPORE-FORMING BACTERIA FROM HYPERSALINE ENVIRONMENTS.

    Science.gov (United States)

    Gladka, G V; Romanovskaya, V A; Tashyreva, H O; Tashyrev, O B

    2015-01-01

    Multi-resistant to extreme factors spore-forming bacteria of Bacillus genus are isolated from hypersaline environments of the Crimea (Ukraine) and the Dead Sea (Israel). Phylogenetic analysis showed distinction of dominating extremophilic culturable species in studied regions. In Crimean environments they are B. mojavensis and B. simplex, in the Dead Sea ecosystem--B. subtilis subsp. spizizenii, B. subtilis subsp. subtilis, B. licheniformis and B. simplex. Isolates are simultaneously halotolerant and resistant to UV radiation. Strains isolated from the Dead Sea and the Crimea environments were resistant to UV: LD90 and LD99.99 made 100-170 J/m2 and 750-1500 J/m2 respectively. Spores showed higher UV-resistance (LD99.99-2500 J/m2) than the vegetative cells. However the number of spores made 0.02-0.007% of the whole cell population, and should not significantly affect the UV LD99.99 value. Isolates of both environments were halotolerant in the range of 0.1-10% NaCl and thermotolerant in the range of 20-50 °C, and didn't grow at 15 °C. Survival strategy of spore-forming bacteria from hypersaline environments under high UV radiation level can be performed by spore formation which minimize cell damage as well as efficient DNA-repair systems that remove damages.

  10. Antiadhesion agents against Gram-positive pathogens.

    Science.gov (United States)

    Cascioferro, Stella; Cusimano, Maria Grazia; Schillaci, Domenico

    2014-01-01

    A fundamental step of Gram-positive pathogenesis is the bacterial adhesion to the host tissue involving interaction between bacterial surface molecules and host ligands. This review is focused on antivirulence compounds that target Gram-positive adhesins and on their potential development as therapeutic agents alternative or complementary to conventional antibiotics in the contrast of pathogens. In particular, compounds that target the sortase A, wall theicoic acid inhibitors, carbohydrates able to bind bacterial proteins and proteins capable of influencing the bacterial adhesion, were described. We further discuss the advantages and disadvantages of this strategy in the development of novel antimicrobials and the future perspective of this research field still at its first steps.

  11. Contamination pathways of spore-forming bacteria in a vegetable cannery.

    Science.gov (United States)

    Durand, Loïc; Planchon, Stella; Guinebretiere, Marie-Hélène; André, Stéphane; Carlin, Frédéric; Remize, Fabienne

    2015-06-02

    Spoilage of low-acid canned food during prolonged storage at high temperatures is caused by heat resistant thermophilic spores of strict or facultative bacteria. Here, we performed a bacterial survey over two consecutive years on the processing line of a French company manufacturing canned mixed green peas and carrots. In total, 341 samples were collected, including raw vegetables, green peas and carrots at different steps of processing, cover brine, and process environment samples. Thermophilic and highly-heat-resistant thermophilic spores growing anaerobically were counted. During vegetable preparation, anaerobic spore counts were significantly decreased, and tended to remain unchanged further downstream in the process. Large variation of spore levels in products immediately before the sterilization process could be explained by occasionally high spore levels on surfaces and in debris of vegetable combined with long residence times in conditions suitable for growth and sporulation. Vegetable processing was also associated with an increase in the prevalence of highly-heat-resistant species, probably due to cross-contamination of peas via blanching water. Geobacillus stearothermophilus M13-PCR genotypic profiling on 112 isolates determined 23 profile-types and confirmed process-driven cross-contamination. Taken together, these findings clarify the scheme of contamination pathway by thermophilic spore-forming bacteria in a vegetable cannery. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Antimicrobial Activity of Carbon Nanoparticles Isolated from Natural Sources against Pathogenic Gram-Negative and Gram-Positive Bacteria

    International Nuclear Information System (INIS)

    Varghese, S.; Jose, S.; Varghese, S.; Kuriakose, S.; Jose, S.

    2013-01-01

    This paper describes the isolation of carbon nanoparticles (CNPs) from kitchen soot, characterization of the CNPs by UV/visible spectroscopy, SEM and XRD, and their antimicrobial action. The antibacterial activity of the isolated carbon nanoparticles was tested against various pathogenic bacterial strains such as Gram-negative Proteus refrigere and Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus and Streptococcus haemolyticus. The inhibition zones were measured, and it was found that the carbon nanoparticles isolated from natural sources are active against these Gram-negative and Gram-positive bacterial strains

  13. One-day pulsed-field gel electrophoresis protocol for rapid determination of emetic Bacillus cereus isolates.

    Science.gov (United States)

    Kaminska, Paulina S; Fiedoruk, Krzysztof; Jankowska, Dominika; Mahillon, Jacques; Nowosad, Karol; Drewicka, Ewa; Zambrzycka, Monika; Swiecicka, Izabela

    2015-04-01

    Bacillus cereus, the Gram-positive and spore-forming ubiquitous bacterium, may cause emesis as the result of food intoxication with cereulide, a heat-stable emetic toxin. Rapid determination of cereulide-positive B. cereus isolates is of highest importance due to consequences of this intoxication for human health and life. Here we present a 1-day pulsed-field gel electrophoresis for emetic B. cereus isolates, which allows rapid and efficient determination of their genomic relatedness and helps determining the source of intoxication in case of outbreaks caused by these bacilli. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Phosphatases modulate the bistable sporulation gene expression pattern in Bacillus subtilis

    NARCIS (Netherlands)

    Veening, JW; Hamoen, LW; Kuipers, OP

    Spore formation in the Gram- positive bacterium Bacillus subtilis is a last resort adaptive response to starvation. To initiate sporulation, the key regulator in this process, Spo0A, needs to be activated by the so-called phosphorelay. Within a sporulating culture of B. subtilis, some cells initiate

  15. DNA fingerprinting of spore-forming bacterial isolates, using Bacillus ...

    African Journals Online (AJOL)

    Bc-repetitive extragenic palindromic polymerase chain reaction (Bc-Rep PCR) analysis was conducted on seven Bacillus thuringiensis isolates accessed from the Deutsche Sammlung von Mikroorganismen und Zellkulturen (DSMZ) culture collection and on five local isolates of entomopathogenic spore-forming bacteria.

  16. Gram-positive rods prevailing in teeth with apical periodontitis undergoing root canal treatment.

    Science.gov (United States)

    Chávez de Paz, L E; Molander, A; Dahlén, G

    2004-09-01

    To identify Gram-positive rods from root canals of teeth with apical periodontitis and to examine their associations with other species. Consecutive root canal samples (RCSs) from 139 teeth undergoing root canal treatment were analyzed prospectively for cultivable microbes. Gram-positive rods in the first RCS submitted after chemo-mechanical preparation were categorised to genus level by selective media and gas-liquid chromatography (GLC), and identified to species level by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Associations between organisms were measured by odds ratios (OR). In the first samples submitted a total of 158 Gram-positive rods, 115 Gram-positive cocci, 26 Gram-negative rods and 9 Gram-negative cocci, were identified. At genus levels Gram-positive rods were classified into: Lactobacillus spp. (38%), Olsenella spp. (18%), Propionibacterium spp. (13%), Actinomyces spp. (12%), Bifidobacterium spp. (13%) and Eubacterium spp. (6%). The most frequent species were Olsenella uli, Lactobacillus paracasei and Propionibacterium propionicum. In subsequent samples taken during treatment, Gram-positive rods were also identified, although the number of strains was considerably reduced. Positive associations were observed between members of the genus lactobacilli and Gram-positive cocci (OR>2). Olsenella uli and Lactobacillus spp. predominated over other Gram-positive rods. A possible association exists between Lactobacillus spp. and Gram-positive cocci in root canals of teeth with apical periodontitis receiving treatment.

  17. Clostridium botulinum Spores Found in Honey from Small Apiaries in Poland

    Directory of Open Access Journals (Sweden)

    Wojtacka Joanna

    2016-12-01

    Full Text Available A total of 102 honey samples collected from small apiaries (≤ 20 hives in Poland were analysed for the presence of Clostridium botulinum spores. The samples were prepared using the dilution centrifugation method and cultured in parallel in cooked meat medium (CMM and tripticase peptone glucose yeast (TPGY enrichment broths. Identification of toxin types A, B, and E of Clostridium botulinum strains was performed with the use of the multiplex PCR method. Positive samples were also subjected to quantitative analysis with the use of Clostridium botulinum Isolation Agar Base (CBAB. The prevalence analysis showed 22 (21.6% samples contaminated with C. botulinum spores. The major serotype detected was botulin neurotoxin type A – 16 (72.7% whereas type B was found in 3 (13.6% honey samples and type E also only in 3 (13.6% honey samples. Dual-toxin-producing strains were noted. The average quantity of spores in PCR - C. botulinum positive samples was 190 in 1 gram of honey.

  18. Selective bowel decontamination results in gram-positive translocation.

    Science.gov (United States)

    Jackson, R J; Smith, S D; Rowe, M I

    1990-05-01

    Colonization by enteric gram-negative bacteria with subsequent translocation is believed to be a major mechanism for infection in the critically ill patient. Selective bowel decontamination (SBD) has been used to control gram-negative infections by eliminating these potentially pathogenic bacteria while preserving anaerobic and other less pathogenic organisms. Infection with gram-positive organisms and anaerobes in two multivisceral transplant patients during SBD led us to investigate the effect of SBD on gut colonization and translocation. Twenty-four rats received enteral polymixin E, tobramycin, amphotericin B, and parenteral cefotaxime for 7 days (PTA + CEF); 23 received parenteral cefotaxime alone (CEF), 19 received the enteral antibiotics alone (PTA), 21 controls received no antibiotics. Cecal homogenates, mesenteric lymph node (MLN), liver, and spleen were cultured. Only 8% of the PTA + CEF group had gram-negative bacteria in cecal culture vs 52% CEF, 84% PTA, and 100% in controls. Log Enterococcal colony counts were higher in the PTA + CEF group (8.0 + 0.9) vs controls (5.4 + 0.4) P less than 0.01. Translocation of Enterococcus to the MLN was significantly increased in the PTA + CEF group (67%) vs controls (0%) P less than 0.01. SBD effectively eliminates gram-negative organisms from the gut in the rat model. Overgrowth and translocation of Enterococcus suggests that infection with gram-positive organisms may be a limitation of SBD.

  19. Dustborne and airborne gram-positive and gram-negative bacteria in high versus low ERMI homes

    Science.gov (United States)

    The study aimed at investigating Gram-positive and Gram-negative bacteria in moldy and non-moldy homes, as defined by the home's Environmental Relative Moldiness Index (ERMI) value. The ERMI values were determined from floor dust samples in 2010 and 2011 and homes were classified...

  20. Gram-positive and gram-negative bacteria induce different patterns of cytokine production in human mononuclear cells irrespective of taxonomic relatedness.

    Science.gov (United States)

    Skovbjerg, Susann; Martner, Anna; Hynsjö, Lars; Hessle, Christina; Olsen, Ingar; Dewhirst, Floyd E; Tham, Wilhelm; Wold, Agnes E

    2010-01-01

    Upon bacterial stimulation, tissue macrophages produce a variety of cytokines that orchestrate the immune response that clears the infection. We have shown that Gram-positives induce higher levels of interleukin-12 (IL-12), interferon-gamma (IFN-gamma), and tumor necrosis factor (TNF) from human peripheral blood mononuclear cells (PBMCs) than do Gram-negatives, which instead induce more of IL-6, IL-8, and IL-10. Here, we study whether these patterns follows or crosses taxonomic borders. PBMCs from blood donors were incubated with UV-inactivated bacteria representing 37 species from five phyla. IL-12, TNF, IL-1beta, IL-6, IL-8, and IL-10 were measured in the supernatants after 24 h and IFN-gamma after 5 days. Irrespective of phylogenetic position, Gram-positive bacteria induced much more IL-12 (nine times more on average) and IFN-gamma (seven times), more TNF (three times), and slightly more IL-1beta (1.5 times) than did Gram-negatives, which instead induced more IL-6 (1.5 times), IL-8 (1.9 times), and IL-10 (3.3 times) than did Gram-positives. A notable exception was the Gram-positive Listeria monocytogenes, which induced very little IL-12, IFN-gamma, and TNF. The results confirm the fundamental difference in innate immune responses to Gram-positive and Gram-negative bacteria, which crosses taxonomic borders and probably reflects differences in cell wall structure.

  1. Bioengineered nisin A derivatives with enhanced activity against both Gram positive and Gram negative pathogens.

    Directory of Open Access Journals (Sweden)

    Des Field

    Full Text Available Nisin is a bacteriocin widely utilized in more than 50 countries as a safe and natural antibacterial food preservative. It is the most extensively studied bacteriocin, having undergone decades of bioengineering with a view to improving function and physicochemical properties. The discovery of novel nisin variants with enhanced activity against clinical and foodborne pathogens has recently been described. We screened a randomized bank of nisin A producers and identified a variant with a serine to glycine change at position 29 (S29G, with enhanced efficacy against S. aureus SA113. Using a site-saturation mutagenesis approach we generated three more derivatives (S29A, S29D and S29E with enhanced activity against a range of Gram positive drug resistant clinical, veterinary and food pathogens. In addition, a number of the nisin S29 derivatives displayed superior antimicrobial activity to nisin A when assessed against a range of Gram negative food-associated pathogens, including E. coli, Salmonella enterica serovar Typhimurium and Cronobacter sakazakii. This is the first report of derivatives of nisin, or indeed any lantibiotic, with enhanced antimicrobial activity against both Gram positive and Gram negative bacteria.

  2. Bioengineered Nisin A Derivatives with Enhanced Activity against Both Gram Positive and Gram Negative Pathogens

    Science.gov (United States)

    Field, Des; Begley, Maire; O’Connor, Paula M.; Daly, Karen M.; Hugenholtz, Floor; Cotter, Paul D.; Hill, Colin; Ross, R. Paul

    2012-01-01

    Nisin is a bacteriocin widely utilized in more than 50 countries as a safe and natural antibacterial food preservative. It is the most extensively studied bacteriocin, having undergone decades of bioengineering with a view to improving function and physicochemical properties. The discovery of novel nisin variants with enhanced activity against clinical and foodborne pathogens has recently been described. We screened a randomized bank of nisin A producers and identified a variant with a serine to glycine change at position 29 (S29G), with enhanced efficacy against S. aureus SA113. Using a site-saturation mutagenesis approach we generated three more derivatives (S29A, S29D and S29E) with enhanced activity against a range of Gram positive drug resistant clinical, veterinary and food pathogens. In addition, a number of the nisin S29 derivatives displayed superior antimicrobial activity to nisin A when assessed against a range of Gram negative food-associated pathogens, including E. coli, Salmonella enterica serovar Typhimurium and Cronobacter sakazakii. This is the first report of derivatives of nisin, or indeed any lantibiotic, with enhanced antimicrobial activity against both Gram positive and Gram negative bacteria. PMID:23056510

  3. Marinicella sediminis sp. nov., isolated from marine sediment

    Science.gov (United States)

    A novel heterotrophic, Gram-stain-negative, aerobic, rod-shaped, pale yellow, non-motile and non-spore-forming bacterium, designated as strain F2**T, was isolated from the marine sediment collected from Weihai coastal, Shandong Province, PR China. Optimal growth occurred at 33 °C (range 10–37 °C), w...

  4. Discovery of novel cell wall-active compounds using P ywaC, a sensitive reporter of cell wall stress, in the model gram-positive bacterium Bacillus subtilis.

    Science.gov (United States)

    Czarny, T L; Perri, A L; French, S; Brown, E D

    2014-06-01

    The emergence of antibiotic resistance in recent years has radically reduced the clinical efficacy of many antibacterial treatments and now poses a significant threat to public health. One of the earliest studied well-validated targets for antimicrobial discovery is the bacterial cell wall. The essential nature of this pathway, its conservation among bacterial pathogens, and its absence in human biology have made cell wall synthesis an attractive pathway for new antibiotic drug discovery. Herein, we describe a highly sensitive screening methodology for identifying chemical agents that perturb cell wall synthesis, using the model of the Gram-positive bacterium Bacillus subtilis. We report on a cell-based pilot screen of 26,000 small molecules to look for cell wall-active chemicals in real time using an autonomous luminescence gene cluster driven by the promoter of ywaC, which encodes a guanosine tetra(penta)phosphate synthetase that is expressed under cell wall stress. The promoter-reporter system was generally much more sensitive than growth inhibition testing and responded almost exclusively to cell wall-active antibiotics. Follow-up testing of the compounds from the pilot screen with secondary assays to verify the mechanism of action led to the discovery of 9 novel cell wall-active compounds. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  5. Taxonomic characterization of the cellulose-degrading bacterium NCIB 10462

    Energy Technology Data Exchange (ETDEWEB)

    Dees, C.; Ringleberg, D.; Scott, T.C. [Oak Ridge National Lab., TN (United States); Phelps, T. [Univ. of Tennessee, Knoxville, TN (United States)

    1994-06-01

    The gram negative cellulase-producing bacterium NCIB 10462 has been previously named Pseudomonas fluorescens subsp. or var. cellulosa. Since there is renewed interest in cellulose-degrading bacteria for use in bioconversion of cellulose to chemical feed stocks and fuels, we re-examined the characteristics of this microorganism to determine its proper taxonomic characterization and to further define it`s true metabolic potential. Metabolic and physical characterization of NCIB 10462 revealed that this was an alkalophilic, non-fermentative, gram negative, oxidase positive, motile, cellulose-degrading bacterium. The aerobic substrate utilization profile of this bacterium was found to have few characteristics consistent with a classification of P. fluorescens with a very low probability match with the genus Sphingomonas. Total lipid analysis did not reveal that any sphingolipid bases are produced by this bacterium. NCIB 10462 was found to grow best aerobically but also grows well in complex media under reducing conditions. NCIB 10462 grew slowly under full anaerobic conditions on complex media but growth on cellulosic media was found only under aerobic conditions. Total fatty acid analysis (MIDI) of NCIB 10462 failed to group this bacterium with a known pseudomonas species. However, fatty acid analysis of the bacteria when grown at temperatures below 37{degrees}C suggest that the organism is a pseudomonad. Since a predominant characteristic of this bacterium is it`s ability to degrade cellulose, we suggest it be called Pseudomonas cellulosa.

  6. Pollen and spores of terrestrial plants

    Science.gov (United States)

    Bernhardt, Christopher E.; Willard, Debra A.; Shennan, Ian; Long, Antony J.; Horton, Benjamin P.

    2015-01-01

    Pollen and spores are valuable tools in reconstructing past sea level and climate because of their ubiquity, abundance, and durability as well as their reciprocity with source vegetation to environmental change (Cronin, 1999; Traverse, 2007; Willard and Bernhardt, 2011). Pollan is found in many sedimentary environments, from freshwater to saltwater, terrestrial to marine. It can be abundant in a minimal amount of sample material, for example half a gram, as concentrations can be as high as four million grains per gram (Traverse, 2007). The abundance of pollen in a sample lends it to robust statistical analysis for the quantitative reconstruction of environments. The outer cell wall is resistant to decay in sediments and allows palynomorphs (pollen and spores) to record changes in plant communities and sea level over millions of years. These characteristics make pollen and spores a powerful tool to use in sea-level research.This chapter describes the biology of pollen and spores and how they are transported and preserved in sediments. We present a methodology for isolating pollen from sediments and a general language and framework to identify pollen as well as light micrographs of a selection of common pollen grains, We then discuss their utility in sea-level research.

  7. The Na+ transport in gram-positive bacteria defect in the Mrp antiporter complex measured with 23Na nuclear magnetic resonance.

    Science.gov (United States)

    Górecki, Kamil; Hägerhäll, Cecilia; Drakenberg, Torbjörn

    2014-01-15

    (23)Na nuclear magnetic resonance (NMR) has previously been used to monitor Na(+) translocation across membranes in gram-negative bacteria and in various other organelles and liposomes using a membrane-impermeable shift reagent to resolve the signals resulting from internal and external Na(+). In this work, the (23)Na NMR method was adapted for measurements of internal Na(+) concentration in the gram-positive bacterium Bacillus subtilis, with the aim of assessing the Na(+) translocation activity of the Mrp (multiple resistance and pH) antiporter complex, a member of the cation proton antiporter-3 (CPA-3) family. The sodium-sensitive growth phenotype observed in a B. subtilis strain with the gene encoding MrpA deleted could indeed be correlated to the inability of this strain to maintain a lower internal Na(+) concentration than an external one. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Hygiene Aspects of the Biogas Process with Emphasis on Spore-Forming Bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Bagge, Elisabeth

    2009-07-01

    Biogas is a renewable source of energy which can be obtained from processing of biowaste. The digested residues can be used as fertiliser. Biowaste intended for biogas production contains pathogenic micro-organisms. A pre-pasteurisation step at 70 deg C for 60 min before anaerobic digestion reduces non spore-forming bacteria such as Salmonella spp. To maintain the standard of the digested residues it must be handled in a strictly hygienic manner to avoid recontamination and re-growth of bacteria. The risk of contamination is particularly high when digested residues are transported in the same vehicles as the raw material. However, heat treatment at 70 deg C for 60 min will not reduce spore-forming bacteria such as Bacillus spp. and Clostridium spp. Spore-forming bacteria, including those that cause serious diseases, can be present in substrate intended for biogas production. The number of species and the quantity of Bacillus spp. and Clostridium spp. in manure, slaughterhouse waste and in samples from different stages during the biogas process were investigated. The number of species of clostridia seemed to decrease following digestion, likewise the quantity. However, Bacillus spp. seemed to pass unaffected through the biogas process. In laboratory-scale experiments the effects on clostridia during pasteurisation and digestion were investigated. Pathogenic clostridia were inoculated in substrates from homogenisation tanks and digester tanks. The inoculated clostridia remained after pasteurisation, but the impacts of digestion differ between different species. Culture followed by identification of C. chauvoei by PCR in samples from cattle died from blackleg, is faster and safer than culture followed by biochemical identification of C. chauvoei. However, for environmental samples the PCR method is not practically applicable for detection of C. chauvoei. To avoid spreading of diseases via biogas plants when digested residues are spread on arable land, a pasteurisation

  9. Antibacterial Activity of Silver-Graphene Quantum Dots Nanocomposites Against Gram-Positive and Gram-Negative Bacteria

    Science.gov (United States)

    Habiba, Khaled (Inventor); Makarov, Vladimir (Inventor); Weiner, Brad R (Inventor); Morell, Gerardo (Inventor)

    2018-01-01

    The invention provides a composite of silver nanoparticles decorated with graphene quantum dots (Ag-GQDs) using pulsed laser synthesis. The nanocomposites were functionalized with polyethylene glycol (PEG). A concentration of 150 .mu.g/mL of Ag-GQDs, a non-toxic level for human cells, exhibits strong antibacterial activity against both Gram-Positive and Gram-Negative Bacteria.

  10. Description of a bacterium associated with redmouth disease of rainbow trout (Salmo gairdneri)

    Science.gov (United States)

    Ross, A.J.; Rucker, R.R.; Ewing, W.H.

    1966-01-01

    A description was given of a gram-negative, peritrichously flagellated, fermentative bacterium that was isolated on numerous occasions from kidney tissues of rainbow trout (Salmo gairdneri) afflicted with redmouth disease. Although the bacteria apparently were members of the family Enterobacteriaceae, it was impossible to determine their taxonomic position within the family with certainty. Hence it was recommended that their taxonomic position remain sub judice for the present. As a temporary designation RM bacterium was used. Redmouth disease was transmitted from infected to normal fish through the medium of water.

  11. Parapiptadenia rigida MYCORRHIZATION WITH SPORES OF Scleroderma citrinum

    Directory of Open Access Journals (Sweden)

    Gerusa Pauli Kist Steffen

    2017-06-01

    Full Text Available Ectomycorrhizal fungal inoculation in forestry seedlings aids plant establishment and growth in the field. The objectives of this study were: to determine the mycorrhizal capacity of the ectomycorrhizal fungus Scleroderma citrinum in Parapiptadenia rigida (red angico seedlings and to evaluate the viability of a mycorrhizal inoculation technique for forest seedlings involving the use of spores. Mature spores were inoculated in the substrate (75% soil and 25% carbonized rice husk, totaling 1.5 grams of fungal spores per liter of substrate. P. rigida seeds were sown in substrates inoculated or not inoculated with fungal spores in presence or absence of Pinus echinata and Eucalyptus citriodora essential oil: not inoculated (T1, inoculated (T2, inoculated more pine essential oil (T3, inoculated more eucalyptus essential oil (T4. Seedlings of Pinus elliottii were used for a positive control of mycorrhizal inoculation (T5 and not inoculated (T6 with fungal spores. At 90 days after sowing, the base stem diameter, height, fresh and dry weight of shoots and roots, percentage of root colonization and Dickson Index were determined. The presence of fungal structures in P. rigida and P. elliottii roots inoculated with S. citrinum spores was observed, demonstrating the occurrence of an ectomycorrhizal association. The application of pine and eucalyptus essential oils in the substrate increased the percentage of ectomycorrhizal colonization in P. rigida seedlings. The addition of S. citrinum mature spores in the substrate used for seedling production is a viable practice for ectomycorrhizal inoculation and it can be used in forest nurseries in controlled mycorrhization programs.

  12. RNases and Helicases in Gram-Positive Bacteria.

    Science.gov (United States)

    Durand, Sylvain; Condon, Ciaran

    2018-04-01

    RNases are key enzymes involved in RNA maturation and degradation. Although they play a crucial role in all domains of life, bacteria, archaea, and eukaryotes have evolved with their own sets of RNases and proteins modulating their activities. In bacteria, these enzymes allow modulation of gene expression to adapt to rapidly changing environments. Today, >20 RNases have been identified in both Escherichia coli and Bacillus subtilis , the paradigms of the Gram-negative and Gram-positive bacteria, respectively. However, only a handful of these enzymes are common to these two organisms and some of them are essential to only one. Moreover, although sets of RNases can be very similar in closely related bacteria such as the Firmicutes Staphylococcus aureus and B. subtilis , the relative importance of individual enzymes in posttranscriptional regulation in these organisms varies. In this review, we detail the role of the main RNases involved in RNA maturation and degradation in Gram-positive bacteria, with an emphasis on the roles of RNase J1, RNase III, and RNase Y. We also discuss how other proteins such as helicases can modulate the RNA-degradation activities of these enzymes.

  13. Peptidoglycan architecture of Gram-positive bacteria by solid-state NMR.

    Science.gov (United States)

    Kim, Sung Joon; Chang, James; Singh, Manmilan

    2015-01-01

    Peptidoglycan is an essential component of cell wall in Gram-positive bacteria with unknown architecture. In this review, we summarize solid-state NMR approaches to address some of the unknowns in the Gram-positive bacteria peptidoglycan architecture: 1) peptidoglycan backbone conformation, 2) PG-lattice structure, 3) variations in the peptidoglycan architecture and composition, 4) the effects of peptidoglycan bridge-length on the peptidoglycan architecture in Fem mutants, 5) the orientation of glycan strands with respect to the membrane, and 6) the relationship between the peptidoglycan structure and the glycopeptide antibiotic mode of action. Solid-state NMR analyses of Staphylococcus aureus cell wall show that peptidoglycan chains are surprisingly ordered and densely packed. The peptidoglycan disaccharide backbone adopts 4-fold screw helical symmetry with the disaccharide unit periodicity of 40Å. Peptidoglycan lattice in the S. aureus cell wall is formed by cross-linked PG stems that have parallel orientations. The structural characterization of Fem-mutants of S. aureus with varying lengths of bridge structures suggests that the PG-bridge length is an important determining factor for the PG architecture. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Nucleotide sequence alignment of hdcA from Gram-positive bacteria.

    Science.gov (United States)

    Diaz, Maria; Ladero, Victor; Redruello, Begoña; Sanchez-Llana, Esther; Del Rio, Beatriz; Fernandez, Maria; Martin, Maria Cruz; Alvarez, Miguel A

    2016-03-01

    The decarboxylation of histidine -carried out mainly by some gram-positive bacteria- yields the toxic dietary biogenic amine histamine (Ladero et al. 2010 〈10.2174/157340110791233256〉 [1], Linares et al. 2016 〈http://dx.doi.org/10.1016/j.foodchem.2015.11.013〉〉 [2]). The reaction is catalyzed by a pyruvoyl-dependent histidine decarboxylase (Linares et al. 2011 〈10.1080/10408398.2011.582813〉 [3]), which is encoded by the gene hdcA. In order to locate conserved regions in the hdcA gene of Gram-positive bacteria, this article provides a nucleotide sequence alignment of all the hdcA sequences from Gram-positive bacteria present in databases. For further utility and discussion, see 〈http://dx.doi.org/ 10.1016/j.foodcont.2015.11.035〉〉 [4].

  15. Nanoparticle targeting of Gram-positive and Gram-negative bacteria for magnetic-based separations of bacterial pathogens

    Science.gov (United States)

    Lu, Hoang D.; Yang, Shirley S.; Wilson, Brian K.; McManus, Simon A.; Chen, Christopher V. H.-H.; Prud'homme, Robert K.

    2017-04-01

    Antimicrobial resistance is a healthcare problem of increasing significance, and there is increasing interest in developing new tools to address bacterial infections. Bacteria-targeting nanoparticles hold promise to improve drug efficacy, compliance, and safety. In addition, nanoparticles can also be used for novel applications, such as bacterial imaging or bioseperations. We here present the use of a scalable block-copolymer-directed self-assembly process, Flash NanoPrecipitation, to form zinc(II)-bis(dipicolylamine) modified nanoparticles that bind to both Gram-positive and Gram-negative bacteria with specificity. Particles have tunable surface ligand densities that change particle avidity and binding efficacy. A variety of materials can be encapsulated into the core of the particles, such as optical dyes or iron oxide colloids, to produce imageable and magnetically active bacterial targeting constructs. As a proof-of-concept, these particles are used to bind and separate bacteria from solution in a magnetic column. Magnetic manipulation and separation would translate to a platform for pathogen identification or removal. These magnetic and targeted nanoparticles enable new methods to address bacterial infections.

  16. Marinobacter nitratireducens sp. nov., a halophilic and lipolytic bacterium isolated from coastal surface sea water

    Digital Repository Service at National Institute of Oceanography (India)

    Bhumika, V.; Ravinder, K.; Korpole, S.; Srinivas, T.N.R.; AnilKumar, P.

    A novel Gram-stain-negative, rod-shaped, motile bacterium, designated strain AK21T , was isolated from coastal surface sea water at Visakhapatnam, India. The strain was positive for oxidase, catalase, lipase, L-proline arylamidase...

  17. Global transcriptome analysis of spore formation in Myxococcus xanthus reveals a locus necessary for cell differentiation

    Directory of Open Access Journals (Sweden)

    Treuner-Lange Anke

    2010-04-01

    Full Text Available Abstract Background Myxococcus xanthus is a Gram negative bacterium that can differentiate into metabolically quiescent, environmentally resistant spores. Little is known about the mechanisms involved in differentiation in part because sporulation is normally initiated at the culmination of a complex starvation-induced developmental program and only inside multicellular fruiting bodies. To obtain a broad overview of the sporulation process and to identify novel genes necessary for differentiation, we instead performed global transcriptome analysis of an artificial chemically-induced sporulation process in which addition of glycerol to vegetatively growing liquid cultures of M. xanthus leads to rapid and synchronized differentiation of nearly all cells into myxospore-like entities. Results Our analyses identified 1 486 genes whose expression was significantly regulated at least two-fold within four hours of chemical-induced differentiation. Most of the previously identified sporulation marker genes were significantly upregulated. In contrast, most genes that are required to build starvation-induced multicellular fruiting bodies, but which are not required for sporulation per se, were not significantly regulated in our analysis. Analysis of functional gene categories significantly over-represented in the regulated genes, suggested large rearrangements in core metabolic pathways, and in genes involved in protein synthesis and fate. We used the microarray data to identify a novel operon of eight genes that, when mutated, rendered cells unable to produce viable chemical- or starvation-induced spores. Importantly, these mutants displayed no defects in building fruiting bodies, suggesting these genes are necessary for the core sporulation process. Furthermore, during the starvation-induced developmental program, these genes were expressed in fruiting bodies but not in peripheral rods, a subpopulation of developing cells which do not sporulate

  18. Cystic neutrophilic granulomatous mastitis: an underappreciated pattern strongly associated with gram-positive bacilli.

    Science.gov (United States)

    Renshaw, Andrew A; Derhagopian, Robert P; Gould, Edwin W

    2011-09-01

    Although granulomatous lobular mastitis is associated with gram-positive bacilli such as Corynebacterium, this association is not well known. We report 3 cases of mastitis caused by gram-positive bacilli. All 3 abscesses were suppurative with distinct enlarged cystic spaces in which rare gram-positive bacilli were identified. Two cases were also granulomatous. Cultures in all 3 cases were negative. All 3 patients recovered after biopsy and tetracycline-based therapy. Infection in the breast by gram-positive bacilli is associated with a distinct histologic pattern, including cystic spaces in the setting of neutrophilic/granulomatous inflammation that can be recognized and should prompt careful search for the organism within enlarged vacuoles.

  19. Long-term cryopreservation of non-spore-forming fungi in Microbank™ beads for plant pathological investigations.

    Science.gov (United States)

    Lakshman, Dilip K; Singh, Vimla; Camacho, Manuel E

    2018-05-01

    Long-term preservation of experimental fungi without genetic, morphological, and pathogenic changes is of paramount importance in mycological and plant pathological investigations. Several cryogenic and non-cryogenic methods are available for the preservation of fungi, but the methods can be cumbersome, hazardous, expensive, and often not suitable for long-term storage of non-spore-forming (sterile) fungi. A method of preservation of spore-forming fungi in commercially available porous beads (Micrbank™) under cryogenic condition was successfully tested for three non-spore-forming basidiomycetes genera: Rhizoctonia solani (teleomorph: Thanatephorus cucumeris) (n = 19), Ceratobasidium species (n = 1), and Waitea circinata (n = 3), and a non-spore forming ascomycetes, Sclerotinia sclerotiorum (n = 1). For comparison, spore-forming ascomycetous fungi, Alternaria alternata (n = 1), Bauveria basiana (n = 2), Botrytis cinerea (n = 1), Fusarium oxysporum f.sp. gladiolii (n = 1), Trichoderma spp. (n = 3), and Thielaviopsis basicola (n = 2) were also cryopreserved in Microbank beads. Viable fungal isolates of all test species were retrieved after five years of storage at -80 °C, which was longer than the viabilities of the corresponding isolates cryopreserved in agar plugs or colonized wheat seeds. Fungi revived from the Microbank beads maintained identical morphology and cultural characteristics of the parent isolates. Randomly selected Rhizoctonia isolates revived from the Microbank beads maintained respective pathological properties of the parent isolates; also, no mutation was detected in the internal transcribed spacer (ITS) ribosomal DNA when compared with respective cultures maintained at ambient temperature. This finding demonstrated the utility of cryopreservation in Microbank beads as a convenient alternative to conventional long-term preservation of a wide group of fungal cultures for plant pathological investigations

  20. Pleural effusion adenosine deaminase: a candidate biomarker to discriminate between Gram-negative and Gram-positive bacterial infections of the pleural space

    Directory of Open Access Journals (Sweden)

    Ruolin Li

    2016-05-01

    Full Text Available OBJECTIVES: Delay in the treatment of pleural infection may contribute to its high mortality. In this retrospective study, we aimed to evaluate the diagnostic accuracy of pleural adenosine deaminase in discrimination between Gram-negative and Gram-positive bacterial infections of the pleural space prior to selecting antibiotics. METHODS: A total of 76 patients were enrolled and grouped into subgroups according to Gram staining: 1 patients with Gram-negative bacterial infections, aged 53.2±18.6 years old, of whom 44.7% had empyemas and 2 patients with Gram-positive bacterial infections, aged 53.5±21.5 years old, of whom 63.1% had empyemas. The pleural effusion was sampled by thoracocentesis and then sent for adenosine deaminase testing, biochemical testing and microbiological culture. The Mann-Whitney U test was used to examine the differences in adenosine deaminase levels between the groups. Correlations between adenosine deaminase and specified variables were also quantified using Spearman’s correlation coefficient. Moreover, receiver operator characteristic analysis was performed to evaluate the diagnostic accuracy of pleural effusion adenosine deaminase. RESULTS: Mean pleural adenosine deaminase levels differed significantly between Gram-negative and Gram-positive bacterial infections of the pleural space (191.8±32.1 U/L vs 81.0±16.9 U/L, p<0.01. The area under the receiver operator characteristic curve was 0.689 (95% confidence interval: 0.570, 0.792, p<0.01 at the cutoff value of 86 U/L. Additionally, pleural adenosine deaminase had a sensitivity of 63.2% (46.0-78.2%; a specificity of 73.7% (56.9-86.6%; positive and negative likelihood ratios of 2.18 and 0.50, respectively; and positive and negative predictive values of 70.6% and 66.7%, respectively. CONCLUSIONS: Pleural effusion adenosine deaminase is a helpful alternative biomarker for early and quick discrimination of Gram-negative from Gram-positive bacterial infections of the

  1. Citreicella manganoxidans sp. nov., a novel manganese oxidizing bacterium isolated from a shallow water hydrothermal vent in Espalamaca (Azores)

    Digital Repository Service at National Institute of Oceanography (India)

    Rajasabapathy, R.; Mohandass, C; Dastager, S.G.; Liu, Q.; Li, W.-J; Colaco, A.

    A Gram-stain negative, non-motile, non-spore forming, aerobic and rod or narrow lemon-shaped bacterial strain, VSW210T, was isolated from surface seawater in a shallow water hydrothermal vent region in Espalamaca (Azores). Strain VSW210...

  2. Isolation of non-sporing anaerobic rods from infections in children.

    Science.gov (United States)

    Brook, I

    1996-07-01

    From 1974 to 1994, 2033 microbiological specimens from children were submitted for cultures for anaerobic bacteria. Fifty-seven isolates of Bifidobacterium spp. were obtained from 55 (3%) children, 67 isolates of Eubacterium spp. from 65 (3%) children and 41 isolates of Lactobacillus spp. from 40 (2%) children. Most Bifidobacterium isolates were from chronic otitis media, abscesses, peritonitis, aspiration pneumonia and paronychia. Most Eubacterium isolates were from abscesses, peritonitis, decubitus ulcers and bites. Lactobacillus spp. were mainly isolated from abscesses, aspiration pneumonia, bacteraemia and conjunctivitis. Most (> 90%) infections from which these species were isolated were polymicrobial and yielded a mixture of aerobic and anaerobic bacteria. The organisms most commonly isolated with the non-sporing anaerobic gram-positive rods were Peptostreptococcus spp., Bacteroides spp., pigmented Prevotella and Porphyromonas spp., Fusobacterium spp., Staphylococcus aureus and Escherichia coli. Most Bacteroides spp. and E. coli were isolated from intra-abdominal infection and skin and soft tissue infection around the rectal area, whereas most Prevotella, Porphyromonas and Fusobacterium isolates were from oropharyngeal, pulmonary and head and neck sites. The predisposing conditions associated with the isolation of non-sporing anaerobic gram-positive rods were previous surgery, malignancy, steroid therapy and immunodeficiency. Antimicrobial therapy was given to 149 (83%) of the 160 patients, in conjunction with surgical drainage or correction of pathology in 89 (56%).

  3. Factors influencing the inactivation of Alicyclobacillus acidoterrestris spores exposed to high hydrostatic pressure in apple juice

    Science.gov (United States)

    Sokołowska, B.; Skąpska, S.; Fonberg-Broczek, M.; Niezgoda, J.; Chotkiewicz, M.; Dekowska, A.; Rzoska, S. J.

    2013-03-01

    Alicyclobacillus acidoterrestris, a thermoacidophilic and spore-forming bacterium, survives the typical pasteurization process and can cause the spoilage of juices, producing compounds associated with disinfectant-like odour (guaiacol, 2,6 - dibromophenol, 2,6 - dichlorophenol). Therefore, the use of other more effective techniques such as high hydrostatic pressure (HHP) is considered for preserving juices. The aim of this study was to search for factors affecting the resistance of A. acidoterrestris spores to HHP. The baroprotective effect of increased solute concentration in apple juice on A. acidoterrestris spores during high pressure processing was observed. During the 45 min pressurization (200 MPa, 50°C) of the spores in concentrated apple juice (71.1°Bx), no significant changes were observed in their number. However, in the juices with a soluble solids content of 35.7, 23.6 and 11.2°Bx, the reduction in spores was 1.3-2.4 log, 2.6-3.3 log and 2.8-4.0 log, respectively. No clear effect of age of spores on the survival under high pressure conditions was found. Spores surviving pressurization and subjected to subsequent HHP treatment showed increased resistance to pressure, by even as much as 2.0 log.

  4. Draft Genome Sequence of the Sulfate-Reducing Bacterium Desulfotomaculum copahuensis Strain CINDEFI1 Isolated from the Geothermal Copahue System, Neuqu?n, Argentina

    OpenAIRE

    Willis Poratti, Graciana; Yaakop, Amira Suriaty; Chan, Chia Sing; Urbieta, M. Sof?a; Chan, Kok-Gan; Ee, Robson; Tan-Guan-Sheng, Adrian; Goh, Kian Mau; Donati, Edgardo R.

    2016-01-01

    Desulfotomaculum copahuensis strain CINDEFI1 is a novel spore-forming sulfate-reducing bacterium isolated from the Copahue volcano area, Argentina. Here, we present its draft genome in which we found genes related with the anaerobic respiration of sulfur compounds similar to those present in the Copahue environment.

  5. Radiosensitivity of spores of Paenibacillus larvae ssp. larvae in honey

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Wanderley Mendes de [Ministerio da Agricultura, Pecuaria e Abastecimento, Rio de Janeiro, RJ (Brazil). Servico de Inspecao de Produtos de Origem Animal]. E-mail: sipa-rj@agricultura.gov.br; Vital, Helio de Carvalho [Centro Tecnologico do Exercito CTEx, Rio de Janeiro, RJ (Brazil). Div. de Defesa Quimica, Biologica e Nuclear]. E-mail: vital@ctex.eb.br; Schuch, Dulce Maria Tocchetto [Ministerio da Agricultura, Pecuaria e Abastecimento, Porto Alegre, RS (Brazil)]. E-mail: micro-lara-rs@agricultura.gov.br

    2007-07-01

    Irradiation, usually used in combination with other conventional methods of conservation, has been proven to be an efficient tool to ensure the safety of many types of foods by destroying pathogenic microorganisms and extending their shelf-lives. This work has investigated the efficacy of gamma irradiation to inactivate spores of the bacterium Paenibacillus larvae that causes the 'American foulbrood', a highly contagious disease still exotic in Brazil that kills bees and contaminates honey, preventing its commercialization and causing great economical losses. In this study, 60 g samples of two types of honey inoculated with 3.5x10{sup 3} spores/mL of that bacterium were irradiated with doses of 0, 5, 7.5, 10, 12.5 and 15 kGy and counted. The analyses indicated a mean reduction of 97.5{+-}0.7% in the number of viable spores exposed to 5 kGy. The application of doses of 7.5 kGy or higher yielded no viable spores above the detection threshold (10/mL). In addition the value of D{sub 10} (3.1{+-}0.3 kGy) was estimated and the logarithm of the population of viable spores of Paenibacillus larvae subsp. larvae was determined as linear and quadratic polynomial functions of the radiation dose. The results indicated that the dose of 10 kGy could be insufficient to assure complete sterilization of honey in some cases while suggesting that 25 kGy would perform such task adequately. (author)

  6. Cellular reprogramming by gram-positive bacterial components: a review.

    LENUS (Irish Health Repository)

    Buckley, Julliette M

    2012-02-03

    LPS tolerance has been the focus of extensive scientific and clinical research over the last several decades in an attempt to elucidate the sequence of changes that occur at a molecular level in tolerized cells. Tolerance to components of gram-positive bacterial cell walls such as bacterial lipoprotein and lipoteichoic acid is a much lesser studied, although equally important, phenomenon. This review will focus on cellular reprogramming by gram-positive bacterial components and examines the alterations in cell surface receptor expression, changes in intracellular signaling, gene expression and cytokine production, and the phenomenon of cross-tolerance.

  7. Antimicrobial activity of metal oxide nanoparticles against Gram-positive and Gram-negative bacteria: a comparative study

    Directory of Open Access Journals (Sweden)

    Azam A

    2012-12-01

    Full Text Available Ameer Azam,1,2 Arham S Ahmed,2 Mohammad Oves,3 Mohammad S Khan,3 Sami S Habib,1 Adnan Memic11Centre of Nanotechnology, King Abdulaziz University, Jeddah, Saudi Arabia; 2Centre of Excellence in Materials Science (Nanomaterials, 3Department of Agricultural Microbiology, Aligarh Muslim University, Aligarh, IndiaBackground: Nanomaterials have unique properties compared to their bulk counterparts. For this reason, nanotechnology has attracted a great deal of attention from the scientific community. Metal oxide nanomaterials like ZnO and CuO have been used industrially for several purposes, including cosmetics, paints, plastics, and textiles. A common feature that these nanoparticles exhibit is their antimicrobial behavior against pathogenic bacteria. In this report, we demonstrate the antimicrobial activity of ZnO, CuO, and Fe2O3 nanoparticles against Gram-positive and Gram-negative bacteria.Methods and results: Nanosized particles of three metal oxides (ZnO, CuO, and Fe2O3 were synthesized by a sol–gel combustion route and characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, and transmission electron microscopy techniques. X-ray diffraction results confirmed the single-phase formation of all three nanomaterials. The particle sizes were observed to be 18, 22, and 28 nm for ZnO, CuO, and Fe2O3, respectively. We used these nanomaterials to evaluate their antibacterial activity against both Gram-negative (Escherichia coli and Pseudomonas aeruginosa and Gram-positive (Staphylococcus aureus and Bacillus subtilis bacteria.Conclusion: Among the three metal oxide nanomaterials, ZnO showed greatest antimicrobial activity against both Gram-positive and Gram-negative bacteria used in this study. It was observed that ZnO nanoparticles have excellent bactericidal potential, while Fe2O3 nanoparticles exhibited the least bactericidal activity. The order of antibacterial activity was demonstrated to be the following: ZnO > CuO > Fe2O3

  8. Mechanistic antimicrobial approach of extracellularly synthesized silver nanoparticles against gram positive and gram negative bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Tamboli, Dhawal P.; Lee, Dae Sung, E-mail: daesung@knu.ac.kr

    2013-09-15

    Highlights: • Bacterial extracelluar enzymes stabilized the silver nanoparticles (AgNPs). • AgNPs formation was characterized by analytical techniques such as UV–vis, TEM, and FTIR. • AgNPs showed obvious antimicrobial activity against both gram positive and gram negative microorganisms. • A mechanism of AgNPs’ antimicrobial activity was proposed. -- Abstract: The development of eco-friendly and reliable processes for the synthesis of nanoparticles has attracted considerable interest in nanotechnology. In this study, an extracellular enzyme system of a newly isolated microorganism, Exiguobacterium sp. KNU1, was used for the reduction of AgNO{sub 3} solutions to silver nanoparticles (AgNPs). The extracellularly biosynthesized AgNPs were characterized by UV–vis spectroscopy, Fourier transform infra-red spectroscopy and transmission electron microscopy. The AgNPs were approximately 30 nm (range 5–50 nm) in size, well-dispersed and spherical. The AgNPs were evaluated for their antimicrobial effects on different gram negative and gram positive bacteria using the minimum inhibitory concentration method. Reasonable antimicrobial activity against Salmonella typhimurium, Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus was observed. The morphological changes occurred in all the microorganisms tested. In particular, E. coli exhibited DNA fragmentation after being treated with the AgNPs. Finally, the mechanism for their bactericidal activity was proposed according to the results of scanning electron microscopy and single cell gel electrophoresis.

  9. Mechanistic antimicrobial approach of extracellularly synthesized silver nanoparticles against gram positive and gram negative bacteria

    International Nuclear Information System (INIS)

    Tamboli, Dhawal P.; Lee, Dae Sung

    2013-01-01

    Highlights: • Bacterial extracelluar enzymes stabilized the silver nanoparticles (AgNPs). • AgNPs formation was characterized by analytical techniques such as UV–vis, TEM, and FTIR. • AgNPs showed obvious antimicrobial activity against both gram positive and gram negative microorganisms. • A mechanism of AgNPs’ antimicrobial activity was proposed. -- Abstract: The development of eco-friendly and reliable processes for the synthesis of nanoparticles has attracted considerable interest in nanotechnology. In this study, an extracellular enzyme system of a newly isolated microorganism, Exiguobacterium sp. KNU1, was used for the reduction of AgNO 3 solutions to silver nanoparticles (AgNPs). The extracellularly biosynthesized AgNPs were characterized by UV–vis spectroscopy, Fourier transform infra-red spectroscopy and transmission electron microscopy. The AgNPs were approximately 30 nm (range 5–50 nm) in size, well-dispersed and spherical. The AgNPs were evaluated for their antimicrobial effects on different gram negative and gram positive bacteria using the minimum inhibitory concentration method. Reasonable antimicrobial activity against Salmonella typhimurium, Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus was observed. The morphological changes occurred in all the microorganisms tested. In particular, E. coli exhibited DNA fragmentation after being treated with the AgNPs. Finally, the mechanism for their bactericidal activity was proposed according to the results of scanning electron microscopy and single cell gel electrophoresis

  10. Impact of spores on the comparative efficacies of five antibiotics for treatment of Bacillus anthracis in an in vitro hollow fiber pharmacodynamic model.

    Science.gov (United States)

    Louie, Arnold; VanScoy, Brian D; Brown, David L; Kulawy, Robert W; Heine, Henry S; Drusano, George L

    2012-03-01

    Bacillus anthracis, the bacterium that causes anthrax, is an agent of bioterrorism. The most effective antimicrobial therapy for B. anthracis infections is unknown. An in vitro pharmacodynamic model of B. anthracis was used to compare the efficacies of simulated clinically prescribed regimens of moxifloxacin, linezolid, and meropenem with the "gold standards," doxycycline and ciprofloxacin. Treatment outcomes for isogenic spore-forming and non-spore-forming strains of B. anthracis were compared. Against spore-forming B. anthracis, ciprofloxacin, moxifloxacin, linezolid, and meropenem reduced the B. anthracis population by 4 log(10) CFU/ml over 10 days. Doxycycline reduced the population of this B. anthracis strain by 5 log(10) CFU/ml (analysis of variance [ANOVA] P = 0.01 versus other drugs). Against an isogenic non-spore-forming strain, meropenem killed the vegetative B. anthracis the fastest, followed by moxifloxacin and ciprofloxacin and then doxycycline. Linezolid offered the lowest bacterial kill rate. Heat shock studies using the spore-producing B. anthracis strain showed that with moxifloxacin, ciprofloxacin, and meropenem therapies the total population was mostly spores, while the population was primarily vegetative bacteria with linezolid and doxycycline therapies. Spores have a profound impact on the rate and extent of killing of B. anthracis. Against spore-forming B. anthracis, the five antibiotics killed the total (spore and vegetative) bacterial population at similar rates (within 1 log(10) CFU/ml of each other). However, bactericidal antibiotics killed vegetative B. anthracis faster than bacteriostatic drugs. Since only vegetative-phase B. anthracis produces the toxins that may kill the infected host, the rate and mechanism of killing of an antibiotic may determine its overall in vivo efficacy. Further studies are needed to examine this important observation.

  11. A Mathematical Model of Intra-Colony Spread of American Foulbrood in European Honeybees (Apis mellifera L..

    Directory of Open Access Journals (Sweden)

    Eduardo O Jatulan

    Full Text Available American foulbrood (AFB is one of the severe infectious diseases of European honeybees (Apis mellifera L. and other Apis species. This disease is caused by a gram-positive, spore-forming bacterium Paenibacillus larvae. In this paper, a compartmental (SI framework model is constructed to represent the spread of AFB within a colony. The model is analyzed to determine the long-term fate of the colony once exposed to AFB spores. It was found out that without effective and efficient treatment, AFB infection eventually leads to colony collapse. Furthermore, infection thresholds were predicted based on the stability of the equilibrium states. The number of infected cell combs is one of the factors that drive disease spread. Our results can be used to forecast the transmission timeline of AFB infection and to evaluate the control strategies for minimizing a possible epidemic.

  12. Daptomycin treatment in Gram-positive vascular graft infections

    Directory of Open Access Journals (Sweden)

    Francisco Arnaiz de las Revillas

    2018-03-01

    Full Text Available Background: Daptomycin is a bactericidal antibiotic approved for the treatment of skin and soft tissue infections and right-side endocarditis. However, there is a lack of published data outlining its usefulness in vascular graft infections (VGI. The aim of this study was to describe the clinical experience of daptomycin use in the treatment of VGI caused by Gram-positive bacteria. Methods: This was a retrospective cohort study of patients diagnosed with VGI receiving daptomycin at a tertiary care hospital during the period January 2010 to December 2012. Results: Of a total 1066 consecutive patients who had undergone vascular grafts (VG, 25 were diagnosed with VGI. Fifteen of these patients (11 prosthetic VG, three autologous VG, one both types received daptomycin (median dose 6.7 mg/kg/day, range 4.1–7.1 mg/kg/day; median age 69 years, range 45–83 years; 80% male. The infected bypass was removed in 13 cases. The most common reason for selecting daptomycin was kidney failure (53%. The Gram-positive organisms isolated were coagulase-negative Staphylococcus (n = 10, Staphylococcus aureus (n = 3 (two methicillin-resistant S. aureus, Enterococcus faecium (n = 2, and Enterococcus faecalis (n = 1. The mean follow-up was 69 months (interquartile range 48–72 months. Ten patients (66.7% achieved complete healing of the VGI. A recurrence of the infection was observed in 100% of patients in whom the bypass was not removed. Among patients who did not achieve complete healing, one needed a supracondylar amputation and one died as a consequence of infection. Five patients received treatment with rifampicin in addition to daptomycin and they were all cured. Conclusions: The use of daptomycin and surgery for Gram-positive VGI was effective and well tolerated, and this may be a good alternative for the treatment of VGI in patients with peripheral arterial disease in whom renal insufficiency is common. Keywords: Daptomycin, Gram-positive, Vascular

  13. Clinical update on linezolid in the treatment of Gram-positive bacterial infections

    Science.gov (United States)

    Ager, Sally; Gould, Kate

    2012-01-01

    Gram-positive pathogens are a significant cause of morbidity and mortality in both community and health care settings. Glycopeptides have traditionally been the antibiotics of choice for multiresistant Gram-positive pathogens but there are problems with their use, including the emergence of glycopeptide-resistant strains, tissue penetration, and achieving and monitoring adequate serum levels. Newer antibiotics such as linezolid, a synthetic oxazolidinone, are available for the treatment of resistant Gram-positive bacteria. Linezolid is active against a wide range of Gram-positive bacteria and has been generally available for the treatment of Gram-positive infections since 2000. There are potential problems with linezolid use, including its bacteriostatic action and the relatively high incidence of reported adverse effects, particularly with long-term use. Long-term use may also be complicated by the development of resistance. However, linezolid has been shown to be clinically useful in the treatment of several serious infections where traditionally bacteriocidal agents have been required and many of its adverse effects are reversible on cessation. It has also been shown to be a cost-effective treatment option in several studies, with its high oral bioavailability allowing an early change from intravenous to oral formulations with consequent earlier patient discharge and lower inpatient costs. PMID:22787406

  14. Oceanospirillum nioense sp. nov., a marine bacterium isolated from sediment sample of Palk bay, India

    Digital Repository Service at National Institute of Oceanography (India)

    Krishna, K.K.; Bhumika, V.; Thomas, M.; AnilKumar, P.; Srinivas, T.N.R.

    A novel Gram-negative, spiral shaped, motile bacterium, designated strain NIO-S6T, was isolated from a sediment sample collected from Offshore Rameswaram, Tamilnadu, India. Strain NIO-S6 sup(T) was found to be positive for oxidase, DNase and lysine...

  15. Genome analysis of the Anerobic Thermohalophilic bacterium Halothermothrix orenii

    Energy Technology Data Exchange (ETDEWEB)

    Mavromatis, Konstantinos; Ivanova, Natalia; Anderson, Iain; Lykidis, Athanasios; Hooper, Sean D.; Sun, Hui; Kunin, Victor; Lapidus, Alla; Hugenholtz, Philip; Patel, Bharat; Kyrpides, Nikos C.

    2008-11-03

    Halothermothirx orenii is a strictly anaerobic thermohalophilic bacterium isolated from sediment of a Tunisian salt lake. It belongs to the order Halanaerobiales in the phylum Firmicutes. The complete sequence revealed that the genome consists of one circular chromosome of 2578146 bps encoding 2451 predicted genes. This is the first genome sequence of an organism belonging to the Haloanaerobiales. Features of both Gram positive and Gram negative bacteria were identified with the presence of both a sporulating mechanism typical of Firmicutes and a characteristic Gram negative lipopolysaccharide being the most prominent. Protein sequence analyses and metabolic reconstruction reveal a unique combination of strategies for thermophilic and halophilic adaptation. H. orenii can serve as a model organism for the study of the evolution of the Gram negative phenotype as well as the adaptation under thermohalophilic conditions and the development of biotechnological applications under conditions that require high temperatures and high salt concentrations.

  16. DMPD: Cellular reprogramming by gram-positive bacterial components: a review. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16885502 Cellular reprogramming by gram-positive bacterial components: a review. Bu...(.csml) Show Cellular reprogramming by gram-positive bacterial components: a review. PubmedID 16885502 Title... Cellular reprogramming by gram-positive bacterial components: a review. Authors

  17. Development of bioprocess for high density cultivation yield of the probiotic Bacillus coagulans and its spores

    Directory of Open Access Journals (Sweden)

    Kavita R. Pandey

    2016-09-01

    Full Text Available Bacillus coagulans is a spore forming lactic acid bacterium. Spore forming bacteria, have been extensively studied and commercialized as probiotics. Probiotics are produced by fermentation technology. There is a limitation to biomass produced by conventional modes of fermentation. With the great demand generated by range of probiotic products, biomass is becoming very valuable for several pharmaceutical, dairy and probiotic companies. Thus, there is a need to develop high cell density cultivation processes for enhanced biomass accumulation. The bioprocess development was carried out in 6.6 L bench top lab scale fermentor. Four different cultivation strategies were employed to develop a bioprocess for higher growth and sporulation efficiencies of probiotic B. coagulans. Batch fermentation of B. coagulans yielded 18 g L-1 biomass (as against 8.0 g L-1 productivity in shake flask with 60% spore efficiency. Fed-batch cultivation was carried out for glucose, which yielded 25 g L-1 of biomass. C/N ratio was very crucial in achieving higher spore titres. Maximum biomass yield recorded was 30 g L-1, corresponding to 3.8 × 1011 cells mL-1 with 81% of cells in sporulated stage. The yield represents increment of 85 times the productivity and 158 times the spore titres relative to the highest reported values for high density cultivation of B. coagulans.

  18. Enterobacter siamensis sp. nov., a transglutaminase-producing bacterium isolated from seafood processing wastewater in Thailand.

    Science.gov (United States)

    Khunthongpan, Suwannee; Bourneow, Chaiwut; H-Kittikun, Aran; Tanasupawat, Somboon; Benjakul, Soottawat; Sumpavapol, Punnanee

    2013-01-01

    A novel strain of Enterobacter, C2361(T), a Gram-negative, non-spore-forming, rod-shaped and facultative anaerobic bacterium with the capability to produce transglutaminase, was isolated from seafood processing wastewater collected from a treatment pond of a seafood factory in Songkhla Province, Thailand. Phylogenetic analyses and phenotypic characteristics, including chemotaxonomic characteristics, showed that the strain was a member of the genus Enterobacter. The 16S rRNA gene sequence similarities between strain C2361(T) and Enterobacter cloacae subsp. cloacae ATCC 13047(T) and Enterobacter cloacae subsp. dissolvens LMG 2683(T) were 97.5 and 97.5%, respectively. Strain C2361(T) showed a low DNA-DNA relatedness with the above-mentioned species. The major fatty acids were C16:0, C17:0cyclo and C14:0. The DNA G+C content was 53.0 mol%. On the basis of the polyphasic evidence gathered in this study, it should be classified as a novel species of the genus Enterobacter for which the name Enterobacter siamensis sp. nov. is proposed. The type strain is C2361(T) (= KCTC 23282(T) = NBRC 107138(T)).

  19. Flavobacterium nitratireducens sp. nov., an amylolytic bacterium of the family Flavobacteriaceae isolated from coastal surface seawater

    Digital Repository Service at National Institute of Oceanography (India)

    Nupur; Bhumika, V.; Srinivas, T.N.R.; AnilKumar, P.

    A novel Gram-negative, rod-shaped, non-motile bacterium, designated strain N1 sup(T), was isolated from a marine water sample collected from the sea shore, Bay of Bengal, Visakhapatnam, India. The strain was positive for starch hydrolysis, nitrate...

  20. Brockia lithotrophica gen. nov., sp. nov., an anaerobic thermophilic bacterium from a terrestrial hot spring.

    Science.gov (United States)

    Perevalova, Anna A; Kublanov, Ilya V; Baslerov, R V; Zhang, Gengxin; Bonch-Osmolovskaya, Elizaveta A

    2013-02-01

    A novel thermophilic bacterium, strain Kam1851(T), was isolated from a terrestrial hot spring of the Uzon Caldera, Kamchatka Peninsula, Russia. Cells of strain Kam1851(T) were spore-forming rods with a gram-positive type of cell wall. Growth was observed between 46 and 78 °C, and pH 5.5-8.5. The optimal growth (doubling time, 6.0 h) was at 60-65 °C and pH 6.5. The isolate was an obligate anaerobe growing in pre-reduced medium only. It grew on mineral medium with molecular hydrogen or formate as electron donors, and elemental sulfur, thiosulfate or polysulfide as electron acceptors. The main cellular fatty acids were C(16 : 0) (34.2 %), iso-C(16 : 0) (18 %), C(18 : 0) (12.8 %) and iso-C(17 : 0) (11.1 %). The G+C content of the genomic DNA of strain Kam1851(T) was 63 mol%. 16S rRNA gene sequence analysis showed that strain Kam1851(T) belonged to the order Thermoanaerobacterales, but it was not closely related to representatives of any genera with validly published names. The most closely related strains, which had no more than 89.2 % sequence similarity, were members of the genera Ammonifex and Caldanaerobacter. On the basis of its phylogenetic position and novel phenotypic features, isolate Kam1851(T) is proposed to represent a novel species in a new genus, Brockia lithotrophica gen. nov., sp. nov.; the type strain of Brockia lithotrophica is Kam1851(T) ( = DSM 22653(T) = VKM B-2685(T)).

  1. The structural bases of long-term anabiosis in non-spore-forming bacteria

    Science.gov (United States)

    Suzina, Natalia E.; Mulyukin, Andrey L.; Dmitriev, Vladimir V.; Nikolaev, Yury A.; Shorokhova, Anna P.; Bobkova, Yulia S.; Barinova, Ekaterina S.; Plakunov, Vladimir K.; El-Registan, Galina I.; Duda, Vitalii I.

    2006-01-01

    Peculiarities of the structural organization in non-spore-forming bacteria associated with long-term anabiosis were revealed both in laboratory cultures and in natural populations isolated from 1 3-Myr-old Eastern Siberian permafrost and tundra soil. Different advanced methods were used, including (a) high-resolution electron microscopy; (b) simulation of in situ conditions in the laboratory by varying the composition of growth medium and cultivation conditions; (c) low-temperature fractionation to isolate and concentrate microbial cells from natural soils; (d) comparative morphological analysis of microbial cells in model cultures and natural soils (in situ). Under laboratory conditions, the intense formation of resting cells by representatives of various taxa of eubacteria and halophilic archaea occurred in 2 9-month-old cultures grown in carbon-, nitrogen-, or phosphorus-limited media, in starved cell suspensions in the presence of sodium silicate, or on soil agar. Among resting cells, we revealed cystlike forms having a complicated structure and common features. These included a thick capsule; a thickened and multiprofile cell wall; the presence of large intramembrane particles on PF- and EF-fracture surfaces; fine-grained or lumpy cytoplasm; and a condensed nucleoid. The general morphological properties, ultrastructural organization, physiological features of cystlike cells, and their ability to germinate under the appropriate conditions suggest the existence of constitutive dormancy in non-spore-forming bacteria. It was found that the majority of microorganisms in permafrost and tundra soil are cystlike cells, very similar to those in laboratory cultures. Anabiotic (resting) cystlike cells are responsible for the survival of non-spore-formers in extreme Earth habitats and may be regarded as possible analogs of extraterrestrial forms of microbial life.

  2. Biocidal Energetic Materials for the Destruction of Spore Forming Bacteria

    Science.gov (United States)

    2015-07-01

    agent (GA). During a reaction the GA generates nucleation sites that promote the formation of bubbles. As the reaction wave passes, the gas pockets...studies have shown iodine producing reactive materials are effective against spore forming bacteria, but are sensitive to the relative humidity in the...testing environment. Results from tests run in relative high humidity environments show a decreased ability of iodine to effectively neutralize

  3. Caldicellulosiruptor obsidiansis sp. nov., an anaerobic, extremely thermophilic, cellulolytic bacterium isolated from Obsidian Pool, Yellowstone National Park.

    Science.gov (United States)

    Hamilton-Brehm, Scott D; Mosher, Jennifer J; Vishnivetskaya, Tatiana; Podar, Mircea; Carroll, Sue; Allman, Steve; Phelps, Tommy J; Keller, Martin; Elkins, James G

    2010-02-01

    A novel, obligately anaerobic, extremely thermophilic, cellulolytic bacterium, designated OB47(T), was isolated from Obsidian Pool, Yellowstone National Park, WY. The isolate was a nonmotile, non-spore-forming, Gram-positive rod approximately 2 microm long by 0.2 microm wide and grew at temperatures between 55 and 85 degrees C, with the optimum at 78 degrees C. The pH range for growth was 6.0 to 8.0, with values of near 7.0 being optimal. Growth on cellobiose produced the fastest specific growth rate at 0.75 h(-1). The organism also displayed fermentative growth on glucose, maltose, arabinose, fructose, starch, lactose, mannose, sucrose, galactose, xylose, arabinogalactan, Avicel, xylan, filter paper, processed cardboard, pectin, dilute acid-pretreated switchgrass, and Populus. OB47(T) was unable to grow on mannitol, fucose, lignin, Gelrite, acetate, glycerol, ribose, sorbitol, carboxymethylcellulose, and casein. Yeast extract stimulated growth, and thiosulfate, sulfate, nitrate, and sulfur were not reduced. Fermentation end products were mainly acetate, H2, and CO2, although lactate and ethanol were produced in 5-liter batch fermentations. The G+C content of the DNA was 35 mol%, and sequence analysis of the small subunit rRNA gene placed OB47(T) within the genus Caldicellulosiruptor. Based on its phylogenetic and phenotypic properties, the isolate is proposed to be designated Caldicellulosiruptor obsidiansis sp. nov. and OB47 is the type strain (ATCC BAA-2073).

  4. Caldicellulosiruptor obsidiansis sp. nov., an Anaerobic, Extremely Thermophilic, Cellulolytic Bacterium Isolated from Obsidian Pool, Yellowstone National Park▿

    Science.gov (United States)

    Hamilton-Brehm, Scott D.; Mosher, Jennifer J.; Vishnivetskaya, Tatiana; Podar, Mircea; Carroll, Sue; Allman, Steve; Phelps, Tommy J.; Keller, Martin; Elkins, James G.

    2010-01-01

    A novel, obligately anaerobic, extremely thermophilic, cellulolytic bacterium, designated OB47T, was isolated from Obsidian Pool, Yellowstone National Park, WY. The isolate was a nonmotile, non-spore-forming, Gram-positive rod approximately 2 μm long by 0.2 μm wide and grew at temperatures between 55 and 85°C, with the optimum at 78°C. The pH range for growth was 6.0 to 8.0, with values of near 7.0 being optimal. Growth on cellobiose produced the fastest specific growth rate at 0.75 h−1. The organism also displayed fermentative growth on glucose, maltose, arabinose, fructose, starch, lactose, mannose, sucrose, galactose, xylose, arabinogalactan, Avicel, xylan, filter paper, processed cardboard, pectin, dilute acid-pretreated switchgrass, and Populus. OB47T was unable to grow on mannitol, fucose, lignin, Gelrite, acetate, glycerol, ribose, sorbitol, carboxymethylcellulose, and casein. Yeast extract stimulated growth, and thiosulfate, sulfate, nitrate, and sulfur were not reduced. Fermentation end products were mainly acetate, H2, and CO2, although lactate and ethanol were produced in 5-liter batch fermentations. The G+C content of the DNA was 35 mol%, and sequence analysis of the small subunit rRNA gene placed OB47T within the genus Caldicellulosiruptor. Based on its phylogenetic and phenotypic properties, the isolate is proposed to be designated Caldicellulosiruptor obsidiansis sp. nov. and OB47 is the type strain (ATCC BAA-2073). PMID:20023107

  5. Genome analysis of the anaerobic thermohalophilic bacterium Halothermothrix orenii.

    Directory of Open Access Journals (Sweden)

    Konstantinos Mavromatis

    Full Text Available Halothermothirx orenii is a strictly anaerobic thermohalophilic bacterium isolated from sediment of a Tunisian salt lake. It belongs to the order Halanaerobiales in the phylum Firmicutes. The complete sequence revealed that the genome consists of one circular chromosome of 2578146 bps encoding 2451 predicted genes. This is the first genome sequence of an organism belonging to the Haloanaerobiales. Features of both Gram positive and Gram negative bacteria were identified with the presence of both a sporulating mechanism typical of Firmicutes and a characteristic Gram negative lipopolysaccharide being the most prominent. Protein sequence analyses and metabolic reconstruction reveal a unique combination of strategies for thermophilic and halophilic adaptation. H. orenii can serve as a model organism for the study of the evolution of the Gram negative phenotype as well as the adaptation under thermohalophilic conditions and the development of biotechnological applications under conditions that require high temperatures and high salt concentrations.

  6. From Genome to Function: Systematic Analysis of the Soil Bacterium Bacillus Subtilis

    Science.gov (United States)

    Crawshaw, Samuel G.; Wipat, Anil

    2001-01-01

    Bacillus subtilis is a sporulating Gram-positive bacterium that lives primarily in the soil and associated water sources. Whilst this bacterium has been studied extensively in the laboratory, relatively few studies have been undertaken to study its activity in natural environments. The publication of the B. subtilis genome sequence and subsequent systematic functional analysis programme have provided an opportunity to develop tools for analysing the role and expression of Bacillus genes in situ. In this paper we discuss analytical approaches that are being developed to relate genes to function in environments such as the rhizosphere. PMID:18628943

  7. Removal of dissolved heavy metals and radionuclides by microbial spores

    International Nuclear Information System (INIS)

    Revis, N.W.; Hadden, C.T.; Edenborn, H.

    1997-01-01

    Microbial systems have been shown to remove specific heavy metals from contaminated aqueous waste to levels acceptable to EPA for environmental release. However, systems capable of removing a variety of heavy metals from aqueous waste to environmentally acceptable levels remain to be reported. The present studies were performed to determine the specificity of spores of the bacterium Bacillus megaterium for the adsorption of dissolved metals and radionuclides from aqueous waste. The spores effectively adsorbed eight heavy metals from a prepared metal mix and from a plating rinse waste to EPA acceptable levels for waste water. These results suggest that spores have multiple binding sites for the adsorption of heavy metals. Spores were also effective in adsorbing the radionuclides 85 strontium and 197 cesium. The presence of multiple sites in spores for the adsorption of heavy metals and radionuclides makes this biosorbent a good candidate for the treatment of aqueous wastes associated with the plating and nuclear industries. 17 refs., 4 tabs

  8. A classification system for plasmids from Enterococci and other Gram-positive bacteria

    DEFF Research Database (Denmark)

    Jensen, Lars Bogø; Garcia-Migura, Lourdes; Valenzuela, Antonio Jesus Sanchez

    2010-01-01

    A classification system for plasmids isolated from enterococci and other Gram-positive bacteria was developed based on 111 published plasmid sequences from enterococci and other Gram-positive bacteria; mostly staphylococci. Based on PCR amplification of conserved areas of the replication initiating....... Furthermore, conjugation experiments were performed obtaining 30 transconjugants when selecting for antimicrobial resistance. Among them 19 gave no positive amplicons indicating presence of rep-families not tested for in this experimental setup....

  9. In vitro activity of XF-73, a novel antibacterial agent, against antibiotic-sensitive and -resistant Gram-positive and Gram-negative bacterial species.

    Science.gov (United States)

    Farrell, David J; Robbins, Marion; Rhys-Williams, William; Love, William G

    2010-06-01

    The antibacterial activity of XF-73, a dicationic porphyrin drug, was investigated against a range of Gram-positive and Gram-negative bacteria with known antibiotic resistance profiles, including resistance to cell wall synthesis, protein synthesis, and DNA and RNA synthesis inhibitors as well as cell membrane-active antibiotics. Antibiotic-sensitive strains for each of the bacterial species tested were also included for comparison purposes. XF-73 was active [minimum inhibitory concentration (MIC) 0.25-4 mg/L] against all of the Gram-positive bacteria tested, irrespective of the antibiotic resistance profile of the isolates, suggesting that the mechanism of action of XF-73 is unique compared with the major antibiotic classes. Gram-negative activity was lower (MIC 1 mg/L to > 64 mg/L). Minimum bactericidal concentration data confirmed that the activity of XF-73 was bactericidal. Time-kill kinetics against healthcare-associated and community-associated meticillin-resistant Staphylococcus aureus isolates demonstrated that XF-73 was rapidly bactericidal, with > 5 log(10) kill obtained after 15 min at 2 x MIC, the earliest time point sampled. The post-antibiotic effect (PAE) for XF-73 under conditions where the PAE for vancomycin was 5.4 h. XF-73 represents a novel broad-spectrum Gram-positive antibacterial drug with potentially beneficial characteristics for the treatment and prevention of Gram-positive bacterial infections. 2010. Published by Elsevier B.V.

  10. Stable transformation of the gram-positive phytopathogenic bacterium Clavibacter michiganensis subsp. sepedonicus with several cloning vectors.

    OpenAIRE

    Laine, M J; Nakhei, H; Dreier, J; Lehtilä, K; Meletzus, D; Eichenlaub, R; Metzler, M C

    1996-01-01

    In this paper we describe transformation of Clavibacter michiganensis subsp. sepedonicus, the potato ring rot bacterium, with plasmid vectors. Three of the plasmids used, pDM100, pDM302, and pDM306, contain the origin of replication from pCM1, a native plasmid of C. michiganensis subsp. michiganensis. We constructed two new cloning vectors, pHN205 and pHN216, by using the origin of replication of pCM2, another native plasmid of C. michiganensis subsp. michiganensis. Plasmids pDM302, pHN205, a...

  11. Neither Single nor a Combination of Routine Laboratory Parameters can Discriminate between Gram-positive and Gram-negative Bacteremia

    Science.gov (United States)

    Ratzinger, Franz; Dedeyan, Michel; Rammerstorfer, Matthias; Perkmann, Thomas; Burgmann, Heinz; Makristathis, Athanasios; Dorffner, Georg; Loetsch, Felix; Blacky, Alexander; Ramharter, Michael

    2015-01-01

    Adequate early empiric antibiotic therapy is pivotal for the outcome of patients with bloodstream infections. In clinical practice the use of surrogate laboratory parameters is frequently proposed to predict underlying bacterial pathogens; however there is no clear evidence for this assumption. In this study, we investigated the discriminatory capacity of predictive models consisting of routinely available laboratory parameters to predict the presence of Gram-positive or Gram-negative bacteremia. Major machine learning algorithms were screened for their capacity to maximize the area under the receiver operating characteristic curve (ROC-AUC) for discriminating between Gram-positive and Gram-negative cases. Data from 23,765 patients with clinically suspected bacteremia were screened and 1,180 bacteremic patients were included in the study. A relative predominance of Gram-negative bacteremia (54.0%), which was more pronounced in females (59.1%), was observed. The final model achieved 0.675 ROC-AUC resulting in 44.57% sensitivity and 79.75% specificity. Various parameters presented a significant difference between both genders. In gender-specific models, the discriminatory potency was slightly improved. The results of this study do not support the use of surrogate laboratory parameters for predicting classes of causative pathogens. In this patient cohort, gender-specific differences in various laboratory parameters were observed, indicating differences in the host response between genders. PMID:26522966

  12. Draft Genome Sequence of the Efficient Bioflocculant-Producing Bacterium Paenibacillus sp. Strain A9

    Science.gov (United States)

    Liu, Jin-liang; Hu, Xiao-min

    2013-01-01

    Paenibacillus sp. strain A9 is an important bioflocculant-producing bacterium, isolated from a soil sample, and is pale pink-pigmented, aerobic, and Gram-positive. Here, we report the draft genome sequence and the initial findings from a preliminary analysis of strain A9, which is a novel species of Paenibacillus. PMID:23618713

  13. PCR detection of thermophilic spore-forming bacteria involved in canned food spoilage.

    Science.gov (United States)

    Prevost, S; Andre, S; Remize, F

    2010-12-01

    Thermophilic bacteria that form highly heat-resistant spores constitute an important group of spoilage bacteria of low-acid canned food. A PCR assay was developed in order to rapidly trace these bacteria. Three PCR primer pairs were designed from rRNA gene sequences. These primers were evaluated for the specificity and the sensitivity of detection. Two primer pairs allowed detection at the species level of Geobacillus stearothermophilus and Moorella thermoacetica/thermoautrophica. The other pair allowed group-specific detection of anaerobic thermophilic bacteria of the genera Thermoanaerobacterium, Thermoanaerobacter, Caldanerobium and Caldanaerobacter. After a single enrichment step, these PCR assays allowed the detection of 28 thermophiles from 34 cans of spoiled low-acid food. In addition, 13 ingredients were screened for the presence of these bacteria. This PCR assay serves as a detection method for strains able to spoil low-acid canned food treated at 55°C. It will lead to better reactivity in the canning industry. Raw materials and ingredients might be qualified not only for quantitative spore contamination, but also for qualitative contamination by highly heat-resistant spores.

  14. Diversity of pigmented Gram-positive bacteria associated with marine macroalgae from Antarctica.

    Science.gov (United States)

    Leiva, Sergio; Alvarado, Pamela; Huang, Ying; Wang, Jian; Garrido, Ignacio

    2015-12-01

    Little is known about the diversity and roles of Gram-positive and pigmented bacteria in Antarctic environments, especially those associated with marine macroorganisms. This work is the first study about the diversity and antimicrobial activity of culturable pigmented Gram-positive bacteria associated with marine Antarctic macroalgae. A total of 31 pigmented Gram-positive strains were isolated from the surface of six species of macroalgae collected in the King George Island, South Shetland Islands. On the basis of 16S rRNA gene sequence similarities ≥99%, 18 phylotypes were defined, which were clustered into 11 genera of Actinobacteria (Agrococcus, Arthrobacter, Brachybacterium, Citricoccus, Kocuria, Labedella, Microbacterium, Micrococcus, Rhodococcus, Salinibacterium and Sanguibacter) and one genus of the Firmicutes (Staphylococcus). It was found that five isolates displayed antimicrobial activity against a set of macroalgae-associated bacteria. The active isolates were phylogenetically related to Agrococcus baldri, Brachybacterium rhamnosum, Citricoccus zhacaiensis and Kocuria palustris. The results indicate that a diverse community of pigmented Gram-positive bacteria is associated with Antartic macroalgae and suggest its potential as a promising source of antimicrobial and pigmented natural compounds. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. Gram-Positive Uropathogens, Polymicrobial Urinary Tract Infection, and the Emerging Microbiota of the Urinary Tract.

    Science.gov (United States)

    Kline, Kimberly A; Lewis, Amanda L

    2016-04-01

    Gram-positive bacteria are a common cause of urinary-tract infection (UTI), particularly among individuals who are elderly, pregnant, or who have other risk factors for UTI. Here we review the epidemiology, virulence mechanisms, and host response to the most frequently isolated Gram-positive uropathogens: Staphylococcus saprophyticus, Enterococcus faecalis, and Streptococcus agalactiae. We also review several emerging, rare, misclassified, and otherwise underreported Gram-positive pathogens of the urinary tract including Aerococcus, Corynebacterium, Actinobaculum, and Gardnerella. The literature strongly suggests that urologic diseases involving Gram-positive bacteria may be easily overlooked due to limited culture-based assays typically utilized for urine in hospital microbiology laboratories. Some UTIs are polymicrobial in nature, often involving one or more Gram-positive bacteria. We herein review the risk factors and recent evidence for mechanisms of bacterial synergy in experimental models of polymicrobial UTI. Recent experimental data has demonstrated that, despite being cleared quickly from the bladder, some Gram-positive bacteria can impact pathogenic outcomes of co-infecting organisms. When taken together, the available evidence argues that Gram-positive bacteria are important uropathogens in their own right, but that some can be easily overlooked because they are missed by routine diagnostic methods. Finally, a growing body of evidence demonstrates that a surprising variety of fastidious Gram-positive bacteria may either reside in or be regularly exposed to the urinary tract and further suggests that their presence is widespread among women, as well as men. Experimental studies in this area are needed; however, there is a growing appreciation that the composition of bacteria found in the bladder could be a potentially important determinant in urologic disease, including susceptibility to UTI.

  16. Gram-negative and -positive bacteria differentiation in blood culture samples by headspace volatile compound analysis.

    Science.gov (United States)

    Dolch, Michael E; Janitza, Silke; Boulesteix, Anne-Laure; Graßmann-Lichtenauer, Carola; Praun, Siegfried; Denzer, Wolfgang; Schelling, Gustav; Schubert, Sören

    2016-12-01

    Identification of microorganisms in positive blood cultures still relies on standard techniques such as Gram staining followed by culturing with definite microorganism identification. Alternatively, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry or the analysis of headspace volatile compound (VC) composition produced by cultures can help to differentiate between microorganisms under experimental conditions. This study assessed the efficacy of volatile compound based microorganism differentiation into Gram-negatives and -positives in unselected positive blood culture samples from patients. Headspace gas samples of positive blood culture samples were transferred to sterilized, sealed, and evacuated 20 ml glass vials and stored at -30 °C until batch analysis. Headspace gas VC content analysis was carried out via an auto sampler connected to an ion-molecule reaction mass spectrometer (IMR-MS). Measurements covered a mass range from 16 to 135 u including CO2, H2, N2, and O2. Prediction rules for microorganism identification based on VC composition were derived using a training data set and evaluated using a validation data set within a random split validation procedure. One-hundred-fifty-two aerobic samples growing 27 Gram-negatives, 106 Gram-positives, and 19 fungi and 130 anaerobic samples growing 37 Gram-negatives, 91 Gram-positives, and two fungi were analysed. In anaerobic samples, ten discriminators were identified by the random forest method allowing for bacteria differentiation into Gram-negative and -positive (error rate: 16.7 % in validation data set). For aerobic samples the error rate was not better than random. In anaerobic blood culture samples of patients IMR-MS based headspace VC composition analysis facilitates bacteria differentiation into Gram-negative and -positive.

  17. Physico-Chemical-Managed Killing of Penicillin-Resistant Static and Growing Gram-Positive and Gram-Negative Vegetative Bacteria

    Science.gov (United States)

    Richmond, Robert Chaffee (Inventor); Schramm, Jr., Harry F. (Inventor); Defalco, Francis G. (Inventor); Farris, III, Alex F. (Inventor)

    2012-01-01

    Systems and methods for the use of compounds from the Hofmeister series coupled with specific pH and temperature to provide rapid physico-chemical-managed killing of penicillin-resistant static and growing Gram-positive and Gram-negative vegetative bacteria. The systems and methods represent the more general physico-chemical enhancement of susceptibility for a wide range of pathological macromolecular targets to clinical management by establishing the reactivity of those targets to topically applied drugs or anti-toxins.

  18. Draft Genome Sequence of the Sulfate-Reducing Bacterium Desulfotomaculum copahuensis Strain CINDEFI1 Isolated from the Geothermal Copahue System, Neuquén, Argentina.

    Science.gov (United States)

    Willis Poratti, Graciana; Yaakop, Amira Suriaty; Chan, Chia Sing; Urbieta, M Sofía; Chan, Kok-Gan; Ee, Robson; Tan-Guan-Sheng, Adrian; Goh, Kian Mau; Donati, Edgardo R

    2016-08-18

    Desulfotomaculum copahuensis strain CINDEFI1 is a novel spore-forming sulfate-reducing bacterium isolated from the Copahue volcano area, Argentina. Here, we present its draft genome in which we found genes related with the anaerobic respiration of sulfur compounds similar to those present in the Copahue environment. Copyright © 2016 Willis Poratti et al.

  19. The Luna stain, an improved selective stain for detection of microsporidian spores in histologic sections

    Science.gov (United States)

    Peterson, Tracy S.; Spitsbergen, Jan M.; Feist, Stephen W.; Kent, Michael L.

    2014-01-01

    Microsporidia in histologic sections are most often diagnosed by observing spores in host tissues. Spores are easy to identify if they occur in large aggregates or xenomas when sections are stained with hematoxylin and eosin (H&E). However, individual spores are not frequently detected in host tissues with conventional H&E staining, particularly if spores are scattered within the tissues, areas of inflammation or small spores in nuclei (i.e., Nucleospora salmonis). Hence, a variety of selective stains that enhance visualization of spores are recommended. We discovered that the Luna stain, used to highlight eosinophils, red blood cells and chitin in arthropods and other invertebrates, also stains spores of Pseudoloma neurophilia. We compared this stain to the Gram, Fite’s acid fast, Giemsa, and H&E stains on eight aquatic microsporidian organisms that were readily available in our two laboratories: Loma salmonae, Glugea anomala, Pseudoloma neurophilia, Pleistophora hyphessobryconis, Pleistophora vermiformis, Glugea sp., Steinhausia mytilovum and an unidentified microsporidian from E. sinensis, UK. Based on tinctorial properties and background staining, the Luna stain performed better for detection of 6 of the 8 microsporidia. Gram stain was superior for the two microsporidia from invertebrates, Steinhausia mytilovum and the unidentified microsporidian from E. sinensis. PMID:21848126

  20. A simple identification method for spore-forming bacteria showing high resistance against γ-rays

    International Nuclear Information System (INIS)

    Koshikawa, Tomihiko; Sone, Koji; Kobayashi, Toshikazu

    1993-01-01

    A simple identification method was developed for spore-forming bacteria which are highly resistant against γ-rays. Among 23 species of Bacillus studied, the spores of Bacillus megaterium, B. cereus, B. thuringiensis, B. pumilus and B. aneurinolyticus showed high resistance against γ-rays as compared with other spores of Bacillus species. Combination of the seven kinds of biochemical tests, namely, the citrate utilization test, nitrate reduction test, starch hydrolysis test, Voges-Proskauer reaction test, gelatine hydrolysis test, mannitol utilization test and xylose utilization test showed a characteristic pattern for each species of Bacillus. The combination pattern of each the above tests with a few supplementary test, if necessary, was useful to identify Bacillus species showing high radiation resistance against γ-rays. The method is specific for B. megaterium, B. thuringiensis and B. pumilus, and highly selective for B. aneurinolyticus and B. cereus. (author)

  1. Anoxybacillus vitaminiphilus sp. nov., a strictly aerobic and moderately thermophilic bacterium isolated from a hot spring.

    Science.gov (United States)

    Zhang, Xin-Qi; Zhang, Zhen-Li; Wu, Nan; Zhu, Xu-Fen; Wu, Min

    2013-11-01

    A strictly aerobic, Gram-stain-positive, motile and spore-forming bacterium, strain 3nP4(T), was isolated from the Puge hot spring located in the south-western geothermal area of China. Strain 3nP4(T) grew at 38-66 °C (optimum 57-60 °C), at pH 6.0-9.3 (optimum 7.0-7.5) and with 0-4 % (w/v) NaCl (optimum 0-0.5 %). Phylogenetic analysis of 16S rRNA gene sequences, as well as DNA-DNA relatedness values, indicated that the isolate represents a novel species of the genus Anoxybacillus, related most closely to Anoxybacillus voinovskiensis DSM 12111(T). Strain 3nP4(T) had diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and one unidentified phospholipid as major polar lipids and iso-C15 : 0 and iso-C17 : 0 as major fatty acids, which are both typical chemotaxonomic characteristics of the genus Anoxybacillus. The mean DNA G+C content of strain 3nP4(T) was 39.2±0.95 mol% (HPLC). A distinctive characteristic of the novel isolate was its extreme reliance on vitamin mixture or yeast extract for growth. Based on data from this taxonomic study using a polyphasic approach, strain 3nP4(T) is considered to represent a novel species of the genus Anoxybacillus, for which the name Anoxybacillus vitaminiphilus sp. nov. is proposed. The type strain is 3nP4(T) ( = CGMCC 1.8979(T) = JCM 16594(T)).

  2. Complete genome sequence of the industrial bacterium Bacillus licheniformis and comparisons with closely related Bacillus species

    Science.gov (United States)

    Rey, Michael W; Ramaiya, Preethi; Nelson, Beth A; Brody-Karpin, Shari D; Zaretsky, Elizabeth J; Tang, Maria; de Leon, Alfredo Lopez; Xiang, Henry; Gusti, Veronica; Clausen, Ib Groth; Olsen, Peter B; Rasmussen, Michael D; Andersen, Jens T; Jørgensen, Per L; Larsen, Thomas S; Sorokin, Alexei; Bolotin, Alexander; Lapidus, Alla; Galleron, Nathalie; Ehrlich, S Dusko; Berka, Randy M

    2004-01-01

    Background Bacillus licheniformis is a Gram-positive, spore-forming soil bacterium that is used in the biotechnology industry to manufacture enzymes, antibiotics, biochemicals and consumer products. This species is closely related to the well studied model organism Bacillus subtilis, and produces an assortment of extracellular enzymes that may contribute to nutrient cycling in nature. Results We determined the complete nucleotide sequence of the B. licheniformis ATCC 14580 genome which comprises a circular chromosome of 4,222,336 base-pairs (bp) containing 4,208 predicted protein-coding genes with an average size of 873 bp, seven rRNA operons, and 72 tRNA genes. The B. licheniformis chromosome contains large regions that are colinear with the genomes of B. subtilis and Bacillus halodurans, and approximately 80% of the predicted B. licheniformis coding sequences have B. subtilis orthologs. Conclusions Despite the unmistakable organizational similarities between the B. licheniformis and B. subtilis genomes, there are notable differences in the numbers and locations of prophages, transposable elements and a number of extracellular enzymes and secondary metabolic pathway operons that distinguish these species. Differences include a region of more than 80 kilobases (kb) that comprises a cluster of polyketide synthase genes and a second operon of 38 kb encoding plipastatin synthase enzymes that are absent in the B. licheniformis genome. The availability of a completed genome sequence for B. licheniformis should facilitate the design and construction of improved industrial strains and allow for comparative genomics and evolutionary studies within this group of Bacillaceae. PMID:15461803

  3. Antimicrobial Activities of Leaf Extracts of Guava (Psidium guajava L.) on Two Gram-Negative and Gram-Positive Bacteria

    Science.gov (United States)

    Biswas, Bipul; Rogers, Kimberly; McLaughlin, Fredrick; Yadav, Anand

    2013-01-01

    Aim. To determine the antimicrobial potential of guava (Psidium guajava) leaf extracts against two gram-negative bacteria (Escherichia coli and Salmonella enteritidis) and two gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) which are some of foodborne and spoilage bacteria. The guava leaves were extracted in four different solvents of increasing polarities (hexane, methanol, ethanol, and water). The efficacy of these extracts was tested against those bacteria through a well-diffusion method employing 50 μL leaf-extract solution per well. According to the findings of the antibacterial assay, the methanol and ethanol extracts of the guava leaves showed inhibitory activity against gram-positive bacteria, whereas the gram-negative bacteria were resistant to all the solvent extracts. The methanol extract had an antibacterial activity with mean zones of inhibition of 8.27 and 12.3 mm, and the ethanol extract had a mean zone of inhibition of 6.11 and 11.0 mm against B. cereus and S. aureus, respectively. On the basis of the present finding, guava leaf-extract might be a good candidate in the search for a natural antimicrobial agent. This study provides scientific understanding to further determine the antimicrobial values and investigate other pharmacological properties. PMID:24223039

  4. Antimicrobial Activities of Leaf Extracts of Guava (Psidium guajava L. on Two Gram-Negative and Gram-Positive Bacteria

    Directory of Open Access Journals (Sweden)

    Bipul Biswas

    2013-01-01

    Full Text Available Aim. To determine the antimicrobial potential of guava (Psidium guajava leaf extracts against two gram-negative bacteria (Escherichia coli and Salmonella enteritidis and two gram-positive bacteria (Staphylococcus aureus and Bacillus cereus which are some of foodborne and spoilage bacteria. The guava leaves were extracted in four different solvents of increasing polarities (hexane, methanol, ethanol, and water. The efficacy of these extracts was tested against those bacteria through a well-diffusion method employing 50 μL leaf-extract solution per well. According to the findings of the antibacterial assay, the methanol and ethanol extracts of the guava leaves showed inhibitory activity against gram-positive bacteria, whereas the gram-negative bacteria were resistant to all the solvent extracts. The methanol extract had an antibacterial activity with mean zones of inhibition of 8.27 and 12.3 mm, and the ethanol extract had a mean zone of inhibition of 6.11 and 11.0 mm against B. cereus and S. aureus, respectively. On the basis of the present finding, guava leaf-extract might be a good candidate in the search for a natural antimicrobial agent. This study provides scientific understanding to further determine the antimicrobial values and investigate other pharmacological properties.

  5. Isolation and characterization of a new CO-utilizing strain, Thermoanaerobacter thermohydrosulfuricus subsp. carboxydovorans, isolated from a geothermal spring in Turkey.

    KAUST Repository

    Balk, Melike

    2009-08-23

    A novel anaerobic, thermophilic, Gram-positive, spore-forming, and sugar-fermenting bacterium (strain TLO) was isolated from a geothermal spring in Ayaş, Turkey. The cells were straight to curved rods, 0.4-0.6 microm in diameter and 3.5-10 microm in length. Spores were terminal and round. The temperature range for growth was 40-80 degrees C, with an optimum at 70 degrees C. The pH optimum was between 6.3 and 6.8. Strain TLO has the capability to ferment a wide variety of mono-, di-, and polysaccharides and proteinaceous substrates, producing mainly lactate, next to acetate, ethanol, alanine, H(2), and CO(2). Remarkably, the bacterium was able to grow in an atmosphere of up to 25% of CO as sole electron donor. CO oxidation was coupled to H(2) and CO(2) formation. The G + C content of the genomic DNA was 35.1 mol%. Based on 16S rRNA gene sequence analysis and the DNA-DNA hybridization data, this bacterium is most closely related to Thermoanaerobacter thermohydrosulfuricus and Thermoanaerobacter siderophilus (99% similarity for both). However, strain TLO differs from Thermoanaerobacter thermohydrosulfuricus in important aspects, such as CO-utilization and lipid composition. These differences led us to propose that strain TLO represents a subspecies of Thermoanaerobacter thermohydrosulfuricus, and we therefore name it Thermoanaerobacter thermohydrosulfuricus subsp. carboxydovorans.

  6. Isolation and characterization of a new CO-utilizing strain, Thermoanaerobacter thermohydrosulfuricus subsp. carboxydovorans, isolated from a geothermal spring in Turkey.

    KAUST Repository

    Balk, Melike; Heilig, Hans G H J; van Eekert, Miriam H A; Stams, Alfons J M; Rijpstra, Irene C; Sinninghe-Damsté , Jaap S; de Vos, Willem M; Kengen, Servé W M

    2009-01-01

    A novel anaerobic, thermophilic, Gram-positive, spore-forming, and sugar-fermenting bacterium (strain TLO) was isolated from a geothermal spring in Ayaş, Turkey. The cells were straight to curved rods, 0.4-0.6 microm in diameter and 3.5-10 microm in length. Spores were terminal and round. The temperature range for growth was 40-80 degrees C, with an optimum at 70 degrees C. The pH optimum was between 6.3 and 6.8. Strain TLO has the capability to ferment a wide variety of mono-, di-, and polysaccharides and proteinaceous substrates, producing mainly lactate, next to acetate, ethanol, alanine, H(2), and CO(2). Remarkably, the bacterium was able to grow in an atmosphere of up to 25% of CO as sole electron donor. CO oxidation was coupled to H(2) and CO(2) formation. The G + C content of the genomic DNA was 35.1 mol%. Based on 16S rRNA gene sequence analysis and the DNA-DNA hybridization data, this bacterium is most closely related to Thermoanaerobacter thermohydrosulfuricus and Thermoanaerobacter siderophilus (99% similarity for both). However, strain TLO differs from Thermoanaerobacter thermohydrosulfuricus in important aspects, such as CO-utilization and lipid composition. These differences led us to propose that strain TLO represents a subspecies of Thermoanaerobacter thermohydrosulfuricus, and we therefore name it Thermoanaerobacter thermohydrosulfuricus subsp. carboxydovorans.

  7. Non-contiguous finished genome sequence and description of Streptococcus varani sp. nov.

    Directory of Open Access Journals (Sweden)

    S. Bakour

    2016-05-01

    Full Text Available Strain FF10T (= CSUR P1489 = DSM 100884 was isolated from the oral cavity of a lizard (Varanus niloticus in Dakar, Senegal. Here we used a polyphasic study including phenotypic and genomic analyses to describe the strain FF10T. Results support strain FF10T being a Gram-positive coccus, facultative anaerobic bacterium, catalase-negative, non-motile and non-spore forming. The sequenced genome counts 2.46 Mb with one chromosome but no plasmid. It exhibits a G+C content of 40.4% and contains 2471 protein-coding and 45 RNA genes. On the basis of these data, we propose the creation of Streptococcus varani sp. nov.

  8. Evaluation of surface contamination of bacteria in various dental clinics with special reference to obligate and facultative anaerobic spore bearing bacilli

    Directory of Open Access Journals (Sweden)

    Kannan I, Jessica Yolanda Jeevitha, Sambandam Cecilia, Jayalakshmi M, Premavathy RK and Shantha S

    2014-07-01

    Full Text Available Introduction: The occupational health and safety is an important prerequisite in dental clinic setup for well being of both the doctor and patient. Both the patient and dentist are always at the risk of infections. Aim and objectives: There is no proper literature on the survey of bacterial spores, especially of Clostridium species in dental clinics. Hence an attempt has been made in the present pilot study to evaluate the surface contamination with special reference to bacterial spores. Materials and methods: Various dental clinics from Chennai city, India were selected for the present study. Samples were collected from two clinics each from endodontic, prosthodontic, orthodontic, and periodontic. In each clinic important places were selected for sampling. The samples were collected in the form of swabs. The swabs thus obtained were inoculated into Robertson Cooked Meat Medium and was incubated in anaerobic condition at 370C for 7 days. Each day the tubes were examined for turbidity and colour change and were noted. At the end of 7th day the smear was prepared from each tube and gram staining was performed. The gram stained slides were examined microscopically for the presence of spore bearing bacilli especially with special reference to terminal spore bearing bacilli. Results and conclusion: From the present study it is clear that the dental clinics invariably posses a lot of aerobic and anaerobic spores irrespective of stringent disinfection procedures. Hence it is mandatory for the dental clinics to undergo periodical microbiological surveillance and to take proper steps in the control of bacterial spores.

  9. Nicotinoprotein methanol dehydrogenase enzymes in Gram-positive methylotrophic bacteria

    NARCIS (Netherlands)

    Hektor, Harm J.; Kloosterman, Harm; Dijkhuizen, Lubbert

    2000-01-01

    A novel type of alcohol dehydrogenase enzyme has been characterized from Gram-positive methylotrophic (Bacillus methanolicus, the actinomycetes Amycolatopsis methanolica and Mycobacterium gastri) and non-methylotrophic bacteria (Rhodococcus strains). Its in vivo role is in oxidation of methanol and

  10. In vitro activity of daptomycin against clinical isolates of Gram-positive bacteria.

    Science.gov (United States)

    Piper, Kerryl E; Steckelberg, James M; Patel, Robin

    2005-08-01

    We determined the activity of daptomycin, a recently FDA-approved antimicrobial agent, against clinical isolates of Gram-positive bacteria, including viridans group streptococci (16 Streptococcus mitis species group, 12 S. mutans species group, 9 S. anginosus species group, 8 S. sanguinis species group, 5 S. salivarius species group) from patients with infective endocarditis, 32 methicillin-resistant Staphylococcus aureus, 32 high-level penicillin-resistant Streptococcus pneumoniae, 38 vancomycin-resistant enterococci (including 1 linezolid-resistant isolate), and the following unusual Gram-positive bacteria: 3 Listeria monocytogenes, 4 Erysipelothrix rhusiopathiae, 9 Corynebacterium species, 10 Abiotrophia/Granulicatella species, 2 Rothia (Stomatococcus) mucilaginosus, and 4 Gemella morbillorum. Daptomycin minimum inhibitory concentration (MIC)(90) values for the viridans group streptococci, methicillin-resistant S. aureus, penicillin-resistant S. pneumoniae, and Enterococcus species were 0.5, 0.5, endocarditis as well as against several types of unusual Gram-positive bacteria that can cause endocarditis.

  11. Regulatory RNAs in Bacillus subtilis: a Gram-Positive Perspective on Bacterial RNA-Mediated Regulation of Gene Expression

    Science.gov (United States)

    Mars, Ruben A. T.; Nicolas, Pierre; Denham, Emma L.

    2016-01-01

    SUMMARY Bacteria can employ widely diverse RNA molecules to regulate their gene expression. Such molecules include trans-acting small regulatory RNAs, antisense RNAs, and a variety of transcriptional attenuation mechanisms in the 5′ untranslated region. Thus far, most regulatory RNA research has focused on Gram-negative bacteria, such as Escherichia coli and Salmonella. Hence, there is uncertainty about whether the resulting insights can be extrapolated directly to other bacteria, such as the Gram-positive soil bacterium Bacillus subtilis. A recent study identified 1,583 putative regulatory RNAs in B. subtilis, whose expression was assessed across 104 conditions. Here, we review the current understanding of RNA-based regulation in B. subtilis, and we categorize the newly identified putative regulatory RNAs on the basis of their conservation in other bacilli and the stability of their predicted secondary structures. Our present evaluation of the publicly available data indicates that RNA-mediated gene regulation in B. subtilis mostly involves elements at the 5′ ends of mRNA molecules. These can include 5′ secondary structure elements and metabolite-, tRNA-, or protein-binding sites. Importantly, sense-independent segments are identified as the most conserved and structured potential regulatory RNAs in B. subtilis. Altogether, the present survey provides many leads for the identification of new regulatory RNA functions in B. subtilis. PMID:27784798

  12. Regulatory RNAs in Bacillus subtilis: a Gram-Positive Perspective on Bacterial RNA-Mediated Regulation of Gene Expression.

    Science.gov (United States)

    Mars, Ruben A T; Nicolas, Pierre; Denham, Emma L; van Dijl, Jan Maarten

    2016-12-01

    Bacteria can employ widely diverse RNA molecules to regulate their gene expression. Such molecules include trans-acting small regulatory RNAs, antisense RNAs, and a variety of transcriptional attenuation mechanisms in the 5' untranslated region. Thus far, most regulatory RNA research has focused on Gram-negative bacteria, such as Escherichia coli and Salmonella. Hence, there is uncertainty about whether the resulting insights can be extrapolated directly to other bacteria, such as the Gram-positive soil bacterium Bacillus subtilis. A recent study identified 1,583 putative regulatory RNAs in B. subtilis, whose expression was assessed across 104 conditions. Here, we review the current understanding of RNA-based regulation in B. subtilis, and we categorize the newly identified putative regulatory RNAs on the basis of their conservation in other bacilli and the stability of their predicted secondary structures. Our present evaluation of the publicly available data indicates that RNA-mediated gene regulation in B. subtilis mostly involves elements at the 5' ends of mRNA molecules. These can include 5' secondary structure elements and metabolite-, tRNA-, or protein-binding sites. Importantly, sense-independent segments are identified as the most conserved and structured potential regulatory RNAs in B. subtilis. Altogether, the present survey provides many leads for the identification of new regulatory RNA functions in B. subtilis. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  13. Diesel degradation and biosurfactant production by Gram-positive ...

    African Journals Online (AJOL)

    The ability of Gram-positive bacteria to degrade diesel increased in a comparable trend as its biosurfactant production increased. The E24 index was highest at 87.6% for isolate D9. Isolates D2, D9 and D10, were identified as Paenibacillus sp. whilst isolate DJLB was found to belong to Stenotrophomonas sp. This study ...

  14. Multi-location gram-positive and gram-negative bacterial protein subcellular localization using gene ontology and multi-label classifier ensemble.

    Science.gov (United States)

    Wang, Xiao; Zhang, Jun; Li, Guo-Zheng

    2015-01-01

    It has become a very important and full of challenge task to predict bacterial protein subcellular locations using computational methods. Although there exist a lot of prediction methods for bacterial proteins, the majority of these methods can only deal with single-location proteins. But unfortunately many multi-location proteins are located in the bacterial cells. Moreover, multi-location proteins have special biological functions capable of helping the development of new drugs. So it is necessary to develop new computational methods for accurately predicting subcellular locations of multi-location bacterial proteins. In this article, two efficient multi-label predictors, Gpos-ECC-mPLoc and Gneg-ECC-mPLoc, are developed to predict the subcellular locations of multi-label gram-positive and gram-negative bacterial proteins respectively. The two multi-label predictors construct the GO vectors by using the GO terms of homologous proteins of query proteins and then adopt a powerful multi-label ensemble classifier to make the final multi-label prediction. The two multi-label predictors have the following advantages: (1) they improve the prediction performance of multi-label proteins by taking the correlations among different labels into account; (2) they ensemble multiple CC classifiers and further generate better prediction results by ensemble learning; and (3) they construct the GO vectors by using the frequency of occurrences of GO terms in the typical homologous set instead of using 0/1 values. Experimental results show that Gpos-ECC-mPLoc and Gneg-ECC-mPLoc can efficiently predict the subcellular locations of multi-label gram-positive and gram-negative bacterial proteins respectively. Gpos-ECC-mPLoc and Gneg-ECC-mPLoc can efficiently improve prediction accuracy of subcellular localization of multi-location gram-positive and gram-negative bacterial proteins respectively. The online web servers for Gpos-ECC-mPLoc and Gneg-ECC-mPLoc predictors are freely accessible

  15. Electron Beam Irradiation Dose Dependently Damages the Bacillus Spore Coat and Spore Membrane

    Directory of Open Access Journals (Sweden)

    S. E. Fiester

    2012-01-01

    Full Text Available Effective control of spore-forming bacilli begs suitable physical or chemical methods. While many spore inactivation techniques have been proven effective, electron beam (EB irradiation has been frequently chosen to eradicate Bacillus spores. Despite its widespread use, there are limited data evaluating the effects of EB irradiation on Bacillus spores. To study this, B. atrophaeus spores were purified, suspended in sterile, distilled water, and irradiated with EB (up to 20 kGy. Irradiated spores were found (1 to contain structural damage as observed by electron microscopy, (2 to have spilled cytoplasmic contents as measured by spectroscopy, (3 to have reduced membrane integrity as determined by fluorescence cytometry, and (4 to have fragmented genomic DNA as measured by gel electrophoresis, all in a dose-dependent manner. Additionally, cytometry data reveal decreased spore size, increased surface alterations, and increased uptake of propidium iodide, with increasing EB dose, suggesting spore coat alterations with membrane damage, prior to loss of spore viability. The present study suggests that EB irradiation of spores in water results in substantial structural damage of the spore coat and inner membrane, and that, along with DNA fragmentation, results in dose-dependent spore inactivation.

  16. Endocarditis : Effects of routine echocardiography during Gram-positive bacteraemia

    NARCIS (Netherlands)

    Vos, F J; Bleeker-Rovers, C P; Sturm, P D; Krabbe, P F M; van Dijk, A P J; Oyen, W J G; Kullberg, B J

    2011-01-01

    BACKGROUND: Despite firm recommendations to perform echocardiography in high-risk patients with Gram-positive bacteraemia, routine echocardiography is not embedded in daily practice in many settings. The aim of this study was to evaluate whether a regime including routine echocardiography results in

  17. Linezolid: a promising option in the treatment of Gram-positives.

    Science.gov (United States)

    Zahedi Bialvaei, Abed; Rahbar, Mohammad; Yousefi, Mehdi; Asgharzadeh, Mohammad; Samadi Kafil, Hossein

    2017-02-01

    Linezolid, an oxazolidinone antimicrobial agent that acts by inhibiting protein synthesis in a unique fashion, is used in the treatment of community-acquired pneumonia, skin and soft-tissue infections and other infections caused by Gram-positive bacteria including VRE and methicillin-resistant staphylococci. Currently, linezolid resistance among these pathogens remains low, commonly linezolid susceptibility testing for this important agent and should be taken into account when considering its therapeutic use. Considering the importance of linezolid in the treatment of infections caused by Gram-positive bacteria, this review was undertaken to optimize the clinical use of this antibiotic. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. Revival and Identification of Bacterial Spores in 25- to 40-Million-Year-Old Dominican Amber

    Science.gov (United States)

    Cano, Raul J.; Borucki, Monica K.

    1995-05-01

    A bacterial spore was revived, cultured, and identified from the abdominal contents of extinct bees preserved for 25 to 40 million years in buried Dominican amber. Rigorous surface decontamination of the amber and aseptic procedures were used during the recovery of the bacterium. Several lines of evidence indicated that the isolated bacterium was of ancient origin and not an extant contaminant. The characteristic enzymatic, biochemical, and 16S ribosomal DNA profiles indicated that the ancient bacterium is most closely related to extant Bacillus sphaericus.

  19. Microbiological Synthesis of 2H-Labeled Phenylalanine, Alanine, Valine, and Leucine/Isoleucine with Different Degrees of Deuterium Enrichment by the Gram-Positive Facultative Methylotrophic Bacterium Вrevibacterium Methylicum

    Directory of Open Access Journals (Sweden)

    Oleg V. Mosin, PhD¹

    2013-06-01

    Full Text Available The microbiological synthesis of [2H]amino acids was performed by the conversion of low molecular weight substrates ([U-2H]MeOH and 2H2O using the Gram-positive aerobic facultative methylotrophic bacterium Brevibacterium methylicum, an L-phenylalanine producer, realizing the NAD+ dependent methanol dehydrogenase (EC 1.6.99.3 variant of the ribulose-5-monophosphate (RuMP cycle of carbon assimilation. In this process, the adapted cells of the methylotroph with enhanced growth characteristics were used on a minimal salt medium M9, supplemented with 2% (v/v [U-2H]MeOH and an increasing gradient of 2Н2O concentration from 0; 24.5, 49.0; 73.5 up to 98% (v/v 2Н2O. Alanine, valine, and leucine/isoleucine were produced and accumulated exogeneously in quantities of 5–6 mol, in addition to the main product of biosynthesis. This method enables the production of [2Н]amino acids with different degrees of deuterium enrichment, depending on the 2Н2O concentration in the growth medium, from 17 at.% 2Н (on the growth medium with 24.5 % (v/v 2Н2О up to 75 at.% 2Н (on the growth medium with 98 % (v/v 2Н2О. This has been confirmed with the data from the electron impact (EI mass spectrometry analysis of the methyl ethers of N-dimethylamino(naphthalene-5-sulfochloride [2H]amino acids under these experimental conditions.

  20. Fighting infections due to multidrug-resistant Gram-positive pathogens.

    Science.gov (United States)

    Cornaglia, G

    2009-03-01

    Growing bacterial resistance in Gram-positive pathogens means that what were once effective and inexpensive treatments for infections caused by these bacteria are now being seriously questioned, including penicillin and macrolides for use against pneumococcal infections and-in hospitals-oxacillin for use against staphylococcal infections. As a whole, multidrug-resistant (MDR) Gram-positive pathogens are rapidly becoming an urgent and sometimes unmanageable clinical problem. Nevertheless, and despite decades of research into the effects of antibiotics, the actual risk posed to human health by antibiotic resistance has been poorly defined; the lack of reliable data concerning the outcomes resulting from antimicrobial resistance stems, in part, from problems with study designs and the methods used in resistence determination. Surprisingly little is known, too, about the actual effectiveness of the many types of intervention aimed at controlling antibiotic resistance. New antibiotics active against MDR Gram-positive pathogens have been recently introduced into clinical practice, and the antibiotic pipeline contains additional compounds at an advanced stage of development, including new glycopeptides, new anti-methicillin-resistant Staphylococcus aureus (MRSA) beta-lactams, and new diaminopyrimidines. Many novel antimicrobial agents are likely to be niche products, endowed with narrow antibacterial spectra and/or targeted at specific clinical problems. Therefore, an important educational goal will be to change the current, long-lasting attitudes of both physicians and customers towards broad-spectrum and multipurpose compounds. Scientific societies, such as the European Society of Clinical Microbiology and Infectious Diseases (ESCMID), must play a leading role in this process.

  1. Morphological characterization of several strains of the rice-pathogenic bacterium Burkholderia glumae in North Sumatra

    Science.gov (United States)

    Hasibuan, M.; Safni, I.; Lisnawita; Lubis, K.

    2018-02-01

    Burkholderia glumae is a quarantine seed-borne bacterial pathogen causing panicle blight disease on rice. This pathogen has been detected in some locations in Java, and recently, farmers in North Sumatra have reported rice yield loss with symptoms similar with those on rice infeced by the rice-pathogenic bacterium B. glumae. This research was aimed to isolate several bacterial strains from several rice varieties in various locations in North Sumatra and characterize the morphology of the strains to detect and identify the unknown bacterial strains presumably B. glumae. Several rice seed varieties were collected from Medan and Deli Serdang Districts. The seed samples were extracted, isolated and purified, then grown in semi-selective media PPGA. The morphological characteristics of the bacterial strains were determined including Gram staining, bacterial colony’s and bacterial cell’s morphology. The results showed that of eleven strains isolated, two strains were Gram negative and nine strains were Gram positive. On the basis of colony morphology, all strains had circular form, flat elevation and cream colour while the colony margin varied, i.e. entire and undulate. Most strains had bacillus/rod shape (8 strains) and only 3 strains were coccus.

  2. The Exosporium of B.cereus Contains a Binding Site for gC1qR/p33: Implication in Spore Attachment and/or Entry.

    Energy Technology Data Exchange (ETDEWEB)

    GHEBREHIWET,B.; TANTRAL, L.; TITMUS, M.A.; PANESSA-WARREN, B.J.; TORTORA, G.T.; WONG, S.S.; WARREN, J.B.

    2008-01-01

    B. cereus, is a member of a genus of aerobic, gram-positive, spore-forming rod-like bacilli, which includes the deadly, B. anthracis. Preliminary experiments have shown that gC1qR binds to B.cereus spores that have been attached to microtiter plates. The present studies were therefore undertaken, to examine if cell surface gC1qR plays a role in B.cereus spore attachment and/or entry. Monolayers of human colon carcinoma (Caco-2) and lung cells were grown to confluency on 6 mm coverslips in shell vials with gentle swirling in a shaker incubator. Then, 2 {micro}l of a suspension of strain SB460 B.cereus spores (3x10{sup 8}/ml, in sterile water), were added and incubated (1-4 h; 36{sup 0} C) in the presence or absence of anti-gC1qR mAb-carbon nanoloops. Examination of these cells by EM revealed that: (1) When B. cereus endospores contacted the apical Caco-2 cell surface, or lung cells, gClqR was simultaneously detectable, indicating upregulation of the molecule. (2) In areas showing spore contact with the cell surface, gClqR expression was often adjacent to the spores in association with microvilli (Caco-2 cells) or cytoskeletal projections (lung cells). (3) Furthermore, the exosporia of the activated and germinating spores were often decorated with mAb-nanoloops. These observations were further corroborated by experiments in which B.cereus spores were readily taken up by monocytes and neutrophils, and this uptake was partially inhibited by mAb 60.11, which recognizes the C1q binding site on gC1qR. Taken together, the data suggest a role, for gC1qR at least in the initial stages of spore attachment and/or entry.

  3. Gram staining.

    Science.gov (United States)

    Coico, Richard

    2005-10-01

    Named after Hans Christian Gram who developed the method in 1884, the Gram stain allows one to distinguish between Gram-positive and Gram-negative bacteria on the basis of differential staining with a crystal violet-iodine complex and a safranin counterstain. The cell walls of Gram-positive organisms retain this complex after treatment with alcohol and appear purple, whereas gram-negative organisms decolorize following such treatment and appear pink. The method described here is useful for assessing bacterial contamination of tissue culture samples or for examining the Gram stain status and morphological features of bacteria isolated from mixed or isolated bacterial cultures.

  4. BACILLUS-METHANOLICUS SP-NOV, A NEW SPECIES OF THERMOTOLERANT, METHANOL-UTILIZING, ENDOSPORE-FORMING BACTERIA

    NARCIS (Netherlands)

    ARFMAN, N; DIJKHUIZEN, L; KIRCHHOF, G; LUDWIG, W; SCHLEIFER, KH; BULYGINA, ES; CHUMAKOV, KM; GOVORUKHINA, NI; TROTSENKO, YA; WHITE, D; SHARP, RJ

    The generic position of 14 strains of gram-positive bacteria able to use methanol as a growth substrate was determined. All are obligately aerobic, thermotolerant organisms that are able to grow at temperatures of 35 to 60-degrees-C. Nine of the strains produce oval spores at a

  5. Rapid and reliable identification of Gram-negative bacteria and Gram-positive cocci by deposition of bacteria harvested from blood cultures onto the MALDI-TOF plate.

    Science.gov (United States)

    Barnini, Simona; Ghelardi, Emilia; Brucculeri, Veronica; Morici, Paola; Lupetti, Antonella

    2015-06-18

    Rapid identification of the causative agent(s) of bloodstream infections using the matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) methodology can lead to increased empirical antimicrobial therapy appropriateness. Herein, we aimed at establishing an easier and simpler method, further referred to as the direct method, using bacteria harvested by serum separator tubes from positive blood cultures and placed onto the polished steel target plate for rapid identification by MALDI-TOF. The results by the direct method were compared with those obtained by MALDI-TOF on bacteria isolated on solid media. Identification of Gram-negative bacilli was 100 % concordant using the direct method or MALDI-TOF on isolated bacteria (96 % with score > 2.0). These two methods were 90 % concordant on Gram-positive cocci (32 % with score > 2.0). Identification by the SepsiTyper method of Gram-positive cocci gave concordant results with MALDI-TOF on isolated bacteria in 87 % of cases (37 % with score > 2.0). The direct method herein developed allows rapid identification (within 30 min) of Gram-negative bacteria and Gram-positive cocci from positive blood cultures and can be used to rapidly report reliable and accurate results, without requiring skilled personnel or the use of expensive kits.

  6. Acid and bile tolerance of spore-forming lactic acid bacteria.

    Science.gov (United States)

    Hyronimus, B; Le Marrec, C; Sassi, A H; Deschamps, A

    2000-11-01

    Criteria for screening probiotics such as bile tolerance and resistance to acids were studied with 13 spore-forming lactic acid producing bacteria. Different strains of Sporolactobacillus, Bacillus laevolacticus, Bacillus racemilacticus and Bacillus coagulans grown in MRS broth were subjected to low pH conditions (2, 2.5 and 3) and increasing bile concentrations. Among these microorganisms, Bacillus laevolacticus DSM 6475 and all Sporolactobacillus strains tested except Sporolactobacillus racemicus IAM 12395, were resistant to pH 3. Only Bacillus racemilacticus and Bacillus coagulans strains were tolerant to bile concentrations over 0.3% (w/v).

  7. Description of Clostridium phoceensis sp. nov., a new species within the genus Clostridium

    Directory of Open Access Journals (Sweden)

    M. Hosny

    2016-11-01

    Full Text Available Clostridium phoceensis sp. nov., strain GD3T (= CSUR P1929 = DSM 100334 is the type strain of C. phoceensis sp. nov., a new species within the genus Clostridium. This strain was isolated from the gut microbiota of a 28-year-old healthy French man. C. phoceensis is a Gram-negative, spore-forming, nonmotile, strictly anaerobic bacterium. We describe its complete genome sequence and annotation, together with its phenotypic characteristics.

  8. Cytokine profile in severe gram-positive and gram-negative abdominal sepsis

    Science.gov (United States)

    Surbatovic, Maja; Popovic, Nada; Vojvodic, Danilo; Milosevic, Ivan; Acimovic, Gordana; Stojicic, Milan; Veljovic, Milic; Jevdjic, Jasna; Djordjevic, Dragan; Radakovic, Sonja

    2015-01-01

    Sepsis is a principal cause of death in critical care units worldwide and consumes considerable healthcare resources. The aim of our study was to determine whether the early cytokine profile can discriminate between Gram-positive and Gram-negative bacteraemia (GPB and GNB, respectively) and to assess the prognostic value regarding outcome in critically ill patients with severe abdominal sepsis. The outcome measure was hospital mortality. Blood samples were obtained from 165 adult patients with confirmed severe abdominal sepsis. Levels of the proinflammatory mediators TNF-α, IL-8, IL-12 and IFN-γ and the anti-inflammatory mediators IL-1ra, IL-4, IL-10 and TGF-β1 were determined and correlated with the nature of the bacteria isolated from the blood culture and outcome. The cytokine profile in our study indicated that the TNF-α levels were 2-fold, IL-8 were 3.3-fold, IFN-γ were 13-fold, IL-1ra were 1.05-fold, IL-4 were 1.4-fold and IL-10 were 1.83-fold higher in the GNB group compared with the GPB group. The TNF-α levels were 4.7-fold, IL-8 were 4.6-fold, IL-1ra were 1.5-fold and IL-10 were 3.3-fold higher in the non-survivors compared with the survivors. PMID:26079127

  9. Characterization of newly isolated Lactobacillus delbrueckii-like strain MF-07 isolated from chicken and its role in isoflavone biotransformation.

    Science.gov (United States)

    Iqbal, Muhammad Farooq; Zhu, Wei-Yun

    2009-02-01

    Cecal microbiota of chicken was screened for bacteria involved in the biotransformation of isoflavones. A new facultative anaerobic bacterium, capable of deglycosylation of the isoflavone genistin, was isolated and identified as a Lactobacillus delbrueckii-like strain. The isolate MF-07 was Gram-positive, facultatively anaerobic, catalase negative, non-spore-forming, nonmotile and a straight rod. The polyphasic taxonomic data, along with 16S rRNA gene sequence comparison, demonstrated that the isolate MF-07 was most closely related to L. delbrueckii group of the Lactobacillus genus. Considerable amounts of genistein were accumulated with genistin as a substrate within the first 12 h of fermentation. Formononetin and daidzein were not metabolized. The influence of several carbon sources on the growth of the isolate MF-07 and biotransformation of genistin was also investigated. This is the first study in which an anaerobic Lactobacillus bacterium from the chicken intestinal tract that metabolizes genistin to produce its bioactive metabolite was identified and characterized.

  10. Bacillus methanolicus sp. nov., a New Species of Thermotolerant, Methanol-Utilizing, Endospore-Forming Bacteria

    NARCIS (Netherlands)

    Arfman, Nico; Dijkhuizen, Lubbert; Kirchhof, Gudrun; Ludwig, Wolfgang; Schleifer, Karl-Heinz; Bulygina, Eugenia S.; Chumakov, Konstantin M.; Govorukhina, Natalya I.; Trotsenko, Yuri A.; White, Duncan; Sharp, Richard J.

    1992-01-01

    The generic position of 14 strains of gram-positive bacteria able to use methanol as a growth substrate was determined. All are obligately aerobic, thermotolerant organisms that are able to grow at temperatures of 35 to 60°C. Nine of the strains produce oval spores at a subterminal-to-central

  11. Extreme Ionizing-Radiation-Resistant Bacterium

    Science.gov (United States)

    Vaishampayan, Parag A.; Venkateswaran, Kasthuri J.; Schwendner, Petra

    2013-01-01

    potential for transfer, and subsequent proliferation, on another solar body such as Mars and Europa. These organisms are more likely to escape planetary protection assays, which only take into account presence of spores. Hence, presences of extreme radiation-resistant Deinococcus in the cleanroom facility where spacecraft are assembled pose a serious risk for integrity of life-detection missions. The microorganism described herein was isolated from the surfaces of the cleanroom facility in which the Phoenix Lander was assembled. The isolated bacterial strain was subjected to a comprehensive polyphasic analysis to characterize its taxonomic position. This bacterium exhibits very low 16SrRNA similarity with any other environmental isolate reported to date. Both phenotypic and phylogenetic analyses clearly indicate that this isolate belongs to the genus Deinococcus and represents a novel species. The name Deinococcus phoenicis was proposed after the Phoenix spacecraft, which was undergoing assembly, testing, and launch operations in the spacecraft assembly facility at the time of isolation. D. phoenicis cells exhibited higher resistance to ionizing radiation (cobalt-60; 14 kGy) than the cells of the D. radiodurans (5 kGy). Thus, it is in the best interest of NASA to thoroughly characterize this organism, which will further assess in determining the potential for forward contamination. Upon the completion of genetic and physiological characteristics of D. phoenicis, it will be added to a planetary protection database to be able to further model and predict the probability of forward contamination.

  12. The Conserved Spore Coat Protein SpoVM Is Largely Dispensable in Clostridium difficile Spore Formation.

    Science.gov (United States)

    Ribis, John W; Ravichandran, Priyanka; Putnam, Emily E; Pishdadian, Keyan; Shen, Aimee

    2017-01-01

    The spore-forming bacterial pathogen Clostridium difficile is a leading cause of health care-associated infections in the United States. In order for this obligate anaerobe to transmit infection, it must form metabolically dormant spores prior to exiting the host. A key step during this process is the assembly of a protective, multilayered proteinaceous coat around the spore. Coat assembly depends on coat morphogenetic proteins recruiting distinct subsets of coat proteins to the developing spore. While 10 coat morphogenetic proteins have been identified in Bacillus subtilis , only two of these morphogenetic proteins have homologs in the Clostridia : SpoIVA and SpoVM. C. difficile SpoIVA is critical for proper coat assembly and functional spore formation, but the requirement for SpoVM during this process was unknown. Here, we show that SpoVM is largely dispensable for C. difficile spore formation, in contrast with B. subtilis . Loss of C. difficile SpoVM resulted in modest decreases (~3-fold) in heat- and chloroform-resistant spore formation, while morphological defects such as coat detachment from the forespore and abnormal cortex thickness were observed in ~30% of spoVM mutant cells. Biochemical analyses revealed that C. difficile SpoIVA and SpoVM directly interact, similarly to their B. subtilis counterparts. However, in contrast with B. subtilis , C. difficile SpoVM was not essential for SpoIVA to encase the forespore. Since C. difficile coat morphogenesis requires SpoIVA-interacting protein L (SipL), which is conserved exclusively in the Clostridia , but not the more broadly conserved SpoVM, our results reveal another key difference between C. difficile and B. subtilis spore assembly pathways. IMPORTANCE The spore-forming obligate anaerobe Clostridium difficile is the leading cause of antibiotic-associated diarrheal disease in the United States. When C. difficile spores are ingested by susceptible individuals, they germinate within the gut and

  13. Amplifiable DNA from Gram-negative and Gram-positive bacteria by a low strength pulsed electric field method

    Science.gov (United States)

    Vitzthum, Frank; Geiger, Georg; Bisswanger, Hans; Elkine, Bentsian; Brunner, Herwig; Bernhagen, Jürgen

    2000-01-01

    An efficient electric field-based procedure for cell disruption and DNA isolation is described. Isoosmotic suspensions of Gram-negative and Gram-positive bacteria were treated with pulsed electric fields of Pulses had an exponential decay waveform with a time constant of 3.4 µs. DNA yield was linearly dependent on time or pulse number, with several thousand pulses needed. Electrochemical side-effects and electrophoresis were minimal. The lysates contained non-fragmented DNA which was readily amplifiable by PCR. As the method was not limited to samples of high specific resistance, it should be applicable to physiological fluids and be useful for genomic and DNA diagnostic applications. PMID:10734214

  14. A Synthetic Dual Drug Sideromycin Induces Gram-Negative Bacteria To Commit Suicide with a Gram-Positive Antibiotic.

    Science.gov (United States)

    Liu, Rui; Miller, Patricia A; Vakulenko, Sergei B; Stewart, Nichole K; Boggess, William C; Miller, Marvin J

    2018-05-10

    Many antibiotics lack activity against Gram-negative bacteria because they cannot permeate the outer membrane or suffer from efflux and, in the case of β-lactams, are degraded by β-lactamases. Herein, we describe the synthesis and studies of a dual drug conjugate (1) of a siderophore linked to a cephalosporin with an attached oxazolidinone. The cephalosporin component of 1 is rapidly hydrolyzed by purified ADC-1 β-lactamase to release the oxazolidinone. Conjugate 1 is active against clinical isolates of Acinetobacter baumannii as well as strains producing large amounts of ADC-1 β-lactamase. Overall, the results are consistent with siderophore-mediated active uptake, inherent activity of the delivered dual drug, and in the presence of β-lactamases, intracellular release of the oxazolidinone upon cleavage of the cephalosporin to allow the freed oxazolidinone to inactivate its target. The ultimate result demonstrates that Gram-positive oxazolidinone antibiotics can be made to be effective against Gram-negative bacteria by β-lactamase triggered release.

  15. Complete genome sequence of Coraliomargarita akajimensis type strain (04OKA010-24T)

    Energy Technology Data Exchange (ETDEWEB)

    Mavromatis, Konstantinos; Abt, Birte; Brambilla, Evelyne; Lapidus, Alla; Copeland, Alex; Desphande, Shweta; Nolan, Matt; Lucas, Susan; Tice, Hope; Cheng, Jan-Fang; Han, Cliff; Detter, John C.; Woyke, Tanja; Goodwin, Lynne; Pitluck, Sam; Held, Brittany; Brettin, Thomas; Tapia, Roxanne; Ivanova, Natalia; Mikhailova, Natalia; Pati, Amrita; Liolios, Konstantinos; Chen, Amy; Palaniappan, Krishna; Land, Miriam; Hauser, Loren; Chang, Yun-Juan; Jeffries, Cynthia D.; Rohde, Manfred; G& #246; ker, Markus; Bristow, James; Eisen, Jonathan A.; Markowitz, Victor; Hugenholtz, Philip; Klenk, Hans-Peter; Kyrpides, Nikos C.

    2010-06-25

    Coraliomargarita akajimensis Yoon et al. 2007 the type species of the genus Coraliomargarita. C. akajimensis is an obligately aerobic, Gram-negative, non-spore-forming, non-motile, spherical bacterium which was isolated from seawater surrounding the hard coral Galaxea fascicularis. C. akajimensis organism is of special interest because of its phylogenetic position in a genomically purely studied area in the bacterial diversity. Here we describe the features of this organism, together with the complete genome sequence, and annotation. This is the first complete genome sequence of a member of the family Puniceicoccaceae. The 3,750,771 bp long genome with its 3,137 protein-coding and 55 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

  16. Comparative activity of tigecycline and tetracycline on Gram-negative and Gram-positive bacteria revealed by a multicentre study in four North European countries

    DEFF Research Database (Denmark)

    Nilsson, Lennart E; Frimodt-Møller, Niels; Vaara, Martti

    2011-01-01

    This study involves a multicentre surveillance of tigecycline and tetracycline activity against Gram-negative and Gram-positive bacteria from primary care centres (PCCs), general hospital wards (GHWs) and intensive care units (ICUs) in Denmark (n = 9), Finland (n = 10), Norway (n = 7) and Sweden (n...

  17. Isolation of an unidentified pink-pigmented bacterium in a clinical specimen.

    OpenAIRE

    Odugbemi, T; Nwofor, C; Joiner, K T

    1988-01-01

    An unidentified pink-pigmented bacterium isolated from a clinical specimen is reported. The organism was oxidase, urease, and catalase positive; it grew on Thayer-Martin and MacConkey media. The isolate is possibly similar to an unnamed taxon (G.L. Gilardi and Y.C. Faur, J. Clin. Microbiol. 20:626-629, 1984); however, it had unique characteristics of nonmotility with no flagellum detectable and was a gram-negative coccoid with a few rods in pairs and negative for starch hydrolysis.

  18. Isolation of an unidentified pink-pigmented bacterium in a clinical specimen.

    Science.gov (United States)

    Odugbemi, T; Nwofor, C; Joiner, K T

    1988-05-01

    An unidentified pink-pigmented bacterium isolated from a clinical specimen is reported. The organism was oxidase, urease, and catalase positive; it grew on Thayer-Martin and MacConkey media. The isolate is possibly similar to an unnamed taxon (G.L. Gilardi and Y.C. Faur, J. Clin. Microbiol. 20:626-629, 1984); however, it had unique characteristics of nonmotility with no flagellum detectable and was a gram-negative coccoid with a few rods in pairs and negative for starch hydrolysis.

  19. High quality draft genome sequence of the moderately halophilic bacterium Pontibacillus yanchengensis Y32(T) and comparison among Pontibacillus genomes.

    Science.gov (United States)

    Huang, Jing; Qiao, Zi Xu; Tang, Jing Wei; Wang, Gejiao

    2015-01-01

    Pontibacillus yanchengensis Y32(T) is an aerobic, motile, Gram-positive, endospore-forming, and moderately halophilic bacterium isolated from a salt field. In this study, we describe the features of P. yanchengensis strain Y32(T) together with a comparison with other four Pontibacillus genomes. The 4,281,464 bp high-quality-draft genome of strain Y32(T) is arranged into 153 contigs containing 3,965 protein-coding genes and 77 RNA encoding genes. The genome of strain Y32(T) possesses many genes related to its halophilic character, flagellar assembly and chemotaxis to support its survival in a salt-rich environment.

  20. Caenorhabditis elegans Predation on Bacillus anthracis: Decontamination of Spore Contaminated Soil with Germinants and Nematodes.

    Science.gov (United States)

    Schelkle, Bettina; Choi, Young; Baillie, Leslie W; Richter, William; Buyuk, Fatih; Celik, Elif; Wendling, Morgan; Sahin, Mitat; Gallagher, Theresa

    2017-01-01

    Remediation of Bacillus anthracis -contaminated soil is challenging and approaches to reduce overall spore levels in environmentally contaminated soil or after intentional release of the infectious disease agent in a safe, low-cost manner are needed. B. anthracis spores are highly resistant to biocides, but once germinated they become susceptible to traditional biocides or potentially even natural predators such as nematodes in the soil environment. Here, we describe a two-step approach to reducing B. anthracis spore load in soil during laboratory trials, whereby germinants and Caenorhabditis elegans nematodes are applied concurrently. While the application of germinants reduced B. anthracis spore load by up to four logs depending on soil type, the addition of nematodes achieved a further log reduction in spore count. These laboratory based results suggest that the combined use of nematodes and germinants could represent a promising approach for the remediation of B. anthracis spore contaminated soil. Originality-Significance Statement: This study demonstrates for the first time the successful use of environmentally friendly decontamination methods to inactivate Bacillus anthracis spores in soil using natural predators of the bacterium, nematode worms.

  1. Antibacterial properties of biosurfactants against selected Gram-positive and -negative bacteria.

    Science.gov (United States)

    Díaz De Rienzo, Mayri A; Stevenson, Paul; Marchant, Roger; Banat, Ibrahim M

    2016-01-01

    The antibacterial properties and ability to disrupt biofilms of biosurfactants (rhamnolipids, sophorolipids) and sodium dodecyl sulphate (SDS) in the presence and absence of selected organic acids were investigated. Pseudomonas aeruginosa PAO1 was inhibited by sophorolipids and SDS at concentrations >5% v/v, and the growth of Escherichia coli NCTC 10418 was also inhibited by sophorolipids and SDS at concentrations >5% and 0.1% v/v, respectively. Bacillus subtilis NCTC 10400 was inhibited by rhamnolipids, sophorolipids and SDS at concentrations >0.5% v/v of all three; the same effect was observed with Staphylococcus aureus ATCC 9144. The ability to attach to surfaces and biofilm formation of P. aeruginosa PAO1, E. coli NCTC 10418 and B. subtilis NCTC 10400 was inhibited by sophorolipids (1% v/v) in the presence of caprylic acid (0.8% v/v). In the case of S. aureus ATCC 9144, the best results were obtained using caprylic acid on its own. It was concluded that sophorolipids are promising compounds for the inhibition/disruption of biofilms formed by Gram-positive and Gram-negative microorganisms and this activity can be enhanced by the presence of booster compounds such as caprylic acid. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Natranaerobaculum magadiense gen. nov., sp. nov., an anaerobic, alkalithermophilic bacterium from soda lake sediment.

    Science.gov (United States)

    Zavarzina, Daria G; Zhilina, Tatyana N; Kuznetsov, Boris B; Kolganova, Tatyana V; Osipov, Georgy A; Kotelev, Mikhail S; Zavarzin, Georgy A

    2013-12-01

    An obligately alkaliphilic, anaerobic, thermo- and halotolerant, spore-forming bacterium was isolated from sediments of soda lake Magadi (Kenya) and designated strain Z-1001(T). Cells of strain Z-1001(T) were straight, Gram-positive rods, slowly motile. Strain Z-1001(T) was found to be an obligate anaerobe. It grew within a pH range from 7.5 to 10.7 with an optimum at 9.25-9.5 (at 40 °C), a temperature range from 20 to 57 °C with an optimum at 45-50 °C, and a NaCl concentration range from 0 to 1.55 M with an optimum at 1.2-1.4 M. Peptides, such as meat and yeast extracts, peptone and tryptone, were fermented by Z-1001(T). Carbohydrates did not support growth. With yeast extract as an electron donor, strain Z-1001(T) reduced S(2)O(3)(2-), NO(-)(3), AsO(3-)(4), Fe(III) citrate and anthraquinone-2,6-disulfonate (AQDS) as electron acceptors. The isolate was able to grow oligotrophically with a very small amount of yeast extract: 0.03 g l(-1). The main fatty acids were C16 : 0, C16 : 1ω7c, C18 : 0 and C18 : 1ω9. The DNA G+C content of the isolate was 35.6 mol%. 16S rRNA gene sequence analysis showed that strain Z-1001(T) is a member of family Natranaerobiaceae, clustering with the type strain of Natranaerobius thermophilus (95.8-96.0 % sequence similarity). On the basis of physiological and phylogenetic data it is proposed that strain Z-1001(T) ( = DSM 24923(T) = VKM B-2666(T)) represents a novel genus and species, Natranaerobaculum magadiense gen. nov., sp. nov.

  3. The combined effect of high pressure and nisin or lysozyme on the inactivation of Alicyclobacillus acidoterrestris spores in apple juice

    Science.gov (United States)

    Sokołowska, B.; Skąpska, S.; Fonberg-Broczek, M.; Niezgoda, J.; Chotkiewicz, M.; Dekowska, A.; Rzoska, S.

    2012-03-01

    Alicyclobacillus acidoterrestris, a thermoacidophilic and spore-forming bacterium is one of the important target micro-organisms in the quality control of acidic canned foods. High pressure pasteurization (HPP) at 50°C was used for the inactivation of A. acidoterrestris spores in apple juice. Pressure applied both in a continuous and oscillatory mode gave the best results when 200 MPa was used. Increasing the pressure to 500 MPa, as well as lowering its value to 100 MPa, had an adverse effect on the effectiveness of the process. The best results were achieved with the use of a combined treatment, involving oscillatory pressurization at 200 MPa, followed by holding the sample for 60 min at atmospheric pressure and subsequent pressurization at 500 MPa, resulting in a reduction in the spore count of 6.15 log. Nisin significantly enhanced the effect of HPP at 300 MPa. Using pressure of 200 MPa for 45 min with a nisin concentration of 250 IU/mL enabled total spore inactivation (over 6 log). No significant effect of lysozyme at a concentration of 0.05 and 0.1 mg/L at 300 MPa was observed.

  4. Inhibitory effect of indole analogs against Paenibacillus larvae, the causal agent of American foulbrood disease.

    Science.gov (United States)

    Alvarado, Israel; Margotta, Joseph W; Aoki, Mai M; Flores, Fernando; Agudelo, Fresia; Michel, Guillermo; Elekonich, Michelle M; Abel-Santos, Ernesto

    2017-09-01

    Paenibacillus larvae, a Gram-positive bacterium, causes American foulbrood (AFB) in honey bee larvae (Apis mellifera Linnaeus [Hymenoptera: Apidae]). P. larvae spores exit dormancy in the gut of bee larvae, the germinated cells proliferate, and ultimately bacteremia kills the host. Hence, spore germination is a required step for establishing AFB disease. We previously found that P. larvae spores germinate in response to l-tyrosine plus uric acid in vitro. Additionally, we determined that indole and phenol blocked spore germination. In this work, we evaluated the antagonistic effect of 35 indole and phenol analogs and identified strong inhibitors of P. larvae spore germination in vitro. We further tested the most promising candidate, 5-chloroindole, and found that it significantly reduced bacterial proliferation. Finally, feeding artificial worker jelly containing anti-germination compounds to AFB-exposed larvae significantly decreased AFB infection in laboratory-reared honey bee larvae. Together, these results suggest that inhibitors of P. larvae spore germination could provide another method to control AFB. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  5. Diverse supramolecular structures formed by self‐assembling proteins of the B acillus subtilis spore coat

    Science.gov (United States)

    Jiang, Shuo; Wan, Qiang; Krajcikova, Daniela; Tang, Jilin; Tzokov, Svetomir B.; Barak, Imrich

    2015-01-01

    Summary Bacterial spores (endospores), such as those of the pathogens C lostridium difficile and B acillus anthracis, are uniquely stable cell forms, highly resistant to harsh environmental insults. B acillus subtilis is the best studied spore‐former and we have used it to address the question of how the spore coat is assembled from multiple components to form a robust, protective superstructure. B . subtilis coat proteins (CotY, CotE, CotV and CotW) expressed in E scherichia coli can arrange intracellularly into highly stable macro‐structures through processes of self‐assembly. Using electron microscopy, we demonstrate the capacity of these proteins to generate ordered one‐dimensional fibres, two‐dimensional sheets and three‐dimensional stacks. In one case (CotY), the high degree of order favours strong, cooperative intracellular disulfide cross‐linking. Assemblies of this kind could form exquisitely adapted building blocks for higher‐order assembly across all spore‐formers. These physically robust arrayed units could also have novel applications in nano‐biotechnology processes. PMID:25872412

  6. Management practices and forage quality affecting the contamination of milk with anaerobic spore-forming bacteria.

    Science.gov (United States)

    Zucali, Maddalena; Bava, Luciana; Colombini, Stefania; Brasca, Milena; Decimo, Marilù; Morandi, Stefano; Tamburini, Alberto; Crovetto, G Matteo

    2015-04-01

    Anaerobic spore-forming bacteria (ASFB) in milk derive from the farm environment, and the use of silages and management practices are the main responsible of milk ASFB contamination. The aim of this study was to evaluate the relationships between feeding, milking routine and cow hygiene and milk and Grana Padano cheese (produced with and without lysozyme) ASFB contamination. The study involved 23 dairy farms. ASFB in corn silage were on average 2.34 ± 0.87 log10 MPN g(-1). For grass, Italian ryegrass and alfalfa, ASFB (log10 MPN g(-1)) were numerically higher for silages (3.22) than hays (2.85). The use of corn silages of high quality (high lactic and acetic acids concentrations) decreased the milk ASFB contamination, whilst the use of herbage silages did not affect it. The presence (>40%) of cows with dirty udders increased the ASFB contamination of milk, while forestripping had a positive effect (-9% ASFB). Ripened Grana Padano had an ASFB count below the analytical limit; Clostridium tyrobutyricum DNA was found only in wheels produced without lysozyme, which also showed late blowing. The factors increasing milk spore contamination were corn silage quality, cow udder hygiene and inadequate milking routine. Late blowing was present only in cheeses without lysozyme. © 2014 Society of Chemical Industry.

  7. Understanding the interaction between an obligate hyperparasitic bacterium, Pasteuria penetrans and its obligate plant-parasitic nematode host, Meloidogyne spp.

    Science.gov (United States)

    Davies, Keith G

    2009-01-01

    Pasteuria penetrans is an endospore-forming bacterium, which is a hyperparasite of root-knot nematodes Meloidogyne spp. that are economically important pests of a wide range of crops. The life cycle of the bacterium and nematode are described with emphasis on the bacterium's potential as a biocontrol agent. Two aspects that currently prohibit the commercial development of the bacterium as a biocontrol agent are the inability to culture it outside its host and its host specificity. Vegetative growth of the bacterium is possible in vitro; however, getting the vegetative stages of the bacterium to enter sporogenesis has been problematic. Insights from genomic survey sequences regarding the role of cation concentration and the phosphorylation of Spo0F have proved useful in inducing vegetative bacteria to sporulate. Similarly, genomic data have also proved useful in understanding the attachment of endospores to the cuticle of infective nematode juveniles, and a Velcro-like model of spore attachment is proposed that involves collagen-like fibres on the surface of the endospore interacting with mucins on the nematode cuticle. Ecological studies of the interactions between Daphnia and Pasteuria ramosa are examined and similarities are drawn between the co-evolution of virulence in the Daphnia system and that of plant-parasitic nematodes.

  8. Trans-generational Immune Priming Protects the Eggs Only against Gram-Positive Bacteria in the Mealworm Beetle

    Science.gov (United States)

    Dubuffet, Aurore; Zanchi, Caroline; Boutet, Gwendoline; Moreau, Jérôme; Teixeira, Maria; Moret, Yannick

    2015-01-01

    In many vertebrates and invertebrates, offspring whose mothers have been exposed to pathogens can exhibit increased levels of immune activity and/or increased survival to infection. Such phenomena, called “Trans-generational immune priming” (TGIP) are expected to provide immune protection to the offspring. As the offspring and their mother may share the same environment, and consequently similar microbial threats, we expect the immune molecules present in the progeny to be specific to the microbes that immune challenged the mother. We provide evidence in the mealworm beetle Tenebrio molitor that the antimicrobial activity found in the eggs is only active against Gram-positive bacteria, even when females were exposed to Gram-negative bacteria or fungi. Fungi were weak inducers of TGIP while we obtained similar levels of anti-Gram-positive activity using different bacteria for the maternal challenge. Furthermore, we have identified an antibacterial peptide from the defensin family, the tenecin 1, which spectrum of activity is exclusively directed toward Gram-positive bacteria as potential contributor to this antimicrobial activity. We conclude that maternal transfer of antimicrobial activity in the eggs of T. molitor might have evolved from persistent Gram-positive bacterial pathogens between insect generations. PMID:26430786

  9. Trans-generational Immune Priming Protects the Eggs Only against Gram-Positive Bacteria in the Mealworm Beetle.

    Directory of Open Access Journals (Sweden)

    Aurore Dubuffet

    2015-10-01

    Full Text Available In many vertebrates and invertebrates, offspring whose mothers have been exposed to pathogens can exhibit increased levels of immune activity and/or increased survival to infection. Such phenomena, called "Trans-generational immune priming" (TGIP are expected to provide immune protection to the offspring. As the offspring and their mother may share the same environment, and consequently similar microbial threats, we expect the immune molecules present in the progeny to be specific to the microbes that immune challenged the mother. We provide evidence in the mealworm beetle Tenebrio molitor that the antimicrobial activity found in the eggs is only active against Gram-positive bacteria, even when females were exposed to Gram-negative bacteria or fungi. Fungi were weak inducers of TGIP while we obtained similar levels of anti-Gram-positive activity using different bacteria for the maternal challenge. Furthermore, we have identified an antibacterial peptide from the defensin family, the tenecin 1, which spectrum of activity is exclusively directed toward Gram-positive bacteria as potential contributor to this antimicrobial activity. We conclude that maternal transfer of antimicrobial activity in the eggs of T. molitor might have evolved from persistent Gram-positive bacterial pathogens between insect generations.

  10. Subcellular localization for Gram positive and Gram negative bacterial proteins using linear interpolation smoothing model.

    Science.gov (United States)

    Saini, Harsh; Raicar, Gaurav; Dehzangi, Abdollah; Lal, Sunil; Sharma, Alok

    2015-12-07

    Protein subcellular localization is an important topic in proteomics since it is related to a protein׳s overall function, helps in the understanding of metabolic pathways, and in drug design and discovery. In this paper, a basic approximation technique from natural language processing called the linear interpolation smoothing model is applied for predicting protein subcellular localizations. The proposed approach extracts features from syntactical information in protein sequences to build probabilistic profiles using dependency models, which are used in linear interpolation to determine how likely is a sequence to belong to a particular subcellular location. This technique builds a statistical model based on maximum likelihood. It is able to deal effectively with high dimensionality that hinders other traditional classifiers such as Support Vector Machines or k-Nearest Neighbours without sacrificing performance. This approach has been evaluated by predicting subcellular localizations of Gram positive and Gram negative bacterial proteins. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Daptomycin: a novel lipopeptide antibiotic against Gram-positive pathogens

    Directory of Open Access Journals (Sweden)

    Andres Beiras-Fernandez

    2010-08-01

    Full Text Available Andres Beiras-Fernandez1,*, Ferdinand Vogt1,*, Ralf Sodian1, Florian Weis21Department of Cardiac Surgery, University Hospital Großhadern, Ludwig-Maximilian-University, Munich, Germany; 2Department of Anesthesiology, University Hospital Großhadern, Ludwig-Maximilian-University, Munich, Germany *Andres Beiras-Fernandez and Ferdinand Vogt contributed equally to this paperAbstract: The aim of this review is to summarize the historical background of drug resistance of Gram-positive pathogens as well as to describe in detail the novel lipopeptide antibiotic daptomycin. Pharmacological and pharmacokinetic aspects are reviewed and the current clinical use of daptomycin is presented. Daptomycin seems to be a reliable drug in the treatment of complicated skin and skin structure infections, infective right-sided endocarditis, and bacteremia caused by Gram-positive agents. Its unique mechanism of action and its low resistance profile, together with its rapid bactericidal action make it a favorable alternative to vancomycin in multi-drug resistant cocci. The role of daptomycin in the treatment of prosthetic material infections, osteomyelitis, and urogenital infections needs to be evaluated in randomized clinical trials.Keywords: daptomycin, multi-drug resistance, methicillin-resistant Staphylococcus aureus (MRSA, pneumonia, urinary tract infection, left-sided endocarditis

  12. Isolation and characterization of a mesophilic heavy-metals-tolerant sulfate-reducing bacterium Desulfomicrobium sp. from an enrichment culture using phosphogypsum as a sulfate source

    International Nuclear Information System (INIS)

    Azabou, Samia; Mechichi, Tahar; Patel, Bharat K.C.; Sayadi, Sami

    2007-01-01

    A sulfate-reducing bacterium, was isolated from a 6 month trained enrichment culture in an anaerobic media containing phosphogypsum as a sulfate source, and, designated strain SA2. Cells of strain SA2 were rod-shaped, did not form spores and stained Gram-negative. Phylogenetic analysis of the 16S rRNA gene sequence of the isolate revealed that it was related to members of the genus Desulfomicrobium (average sequence similarity of 98%) with Desulfomicrobium baculatum being the most closely related (sequence similarity of 99%). Strain SA2 used thiosulfate, sulfate, sulfite and elemental sulfur as electron acceptors and produced sulfide. Strain SA2 reduced sulfate contained in 1-20 g/L phosphogypsum to sulfide with reduction of sulfate contained in 2 g/L phosphogypsum being the optimum concentration. Strain SA2 grew with metalloid, halogenated and non-metal ions present in phosphogypsum and with added high concentrations of heavy metals (125 ppm Zn and 100 ppm Ni, W, Li and Al). The relative order for the inhibitory metal concentrations, based on the IC 50 values, was Cu, Te > Cd > Fe, Co, Mn > F, Se > Ni, Al, Li > Zn

  13. Sporosalibacterium faouarense gen. nov., sp. nov., a moderately halophilic bacterium isolated from oil-contaminated soil.

    Science.gov (United States)

    Rezgui, Raja; Ben Ali Gam, Zouhaier; Ben Hamed, Said; Fardeau, Marie-Laure; Cayol, Jean-Luc; Maaroufi, Abderrazak; Labat, Marc

    2011-01-01

    A novel strictly anaerobic, moderately halophilic and mesophilic bacterium, designated strain SOL3f37(T), was isolated from a hydrocarbon-polluted soil surrounding a deep petroleum environment located in south Tunisia. Cells of strain SOL3f37(T) stained Gram-positive and were motile, straight and spore-forming. Strain SOL3f37(T) had a typical Gram-positive-type cell-wall structure, unlike the thick, multilayered cell wall of its closest relative Clostridiisalibacter paucivorans. The major fatty acids were iso-C(15 : 0) (41 %), iso-C(14 : 0) 3-OH and/or iso-C(15 : 0) dimethyl acetal (21.6 %), iso-C(13 : 0) (4.4 %), anteiso-C(15 : 0) (3.9 %) and iso-C(15 : 1) (2.8 %). Strain SOL3f37(T) grew between 20 and 48 °C (optimum 40 °C) and at pH 6.2-8.1 (optimum pH 6.9). Strain SOL3f37(T) required at least 0.5 NaCl l(-1) and grew in the presence of NaCl concentrations up to 150 g l(-1) (optimum 40 g l(-1)). Yeast extract (2 g l(-1)) was required for degradation of pyruvate, fumarate, fructose, glucose and mannitol. Also, strain SOL3f37(T) grew heterotrophically on yeast extract, peptone and bio-Trypticase, but was unable to grow on Casamino acids. Sulfate, thiosulfate, sulfite, elemental sulfur, fumarate, nitrate and nitrite were not reduced. The DNA G+C content was 30.7 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain SOL3f37(T) was a member of the family Clostridiaceae in the order Clostridiales; strain SOL3f37(T) was related to members of various genera of the family Clostridiaceae. It exhibited highest 16S rRNA gene sequence similarity (93.4 %) with Clostridiisalibacter paucivorans 37HS60(T), 91.8 % with Thermohalobacter berrensis CTT3(T) and 91.7 % with Caloranaerobacter azorensis MV1087(T). On the basis of genotypic, phenotypic and phylogenetic data, it is suggested that strain SOL3f37(T) represents a novel species in a new genus. The name Sporosalibacterium faouarense gen. nov., sp. nov. is

  14. Toxigenic potential and heat survival of spore-forming bacteria isolated from bread and ingredients.

    Science.gov (United States)

    De Bellis, Palmira; Minervini, Fiorenza; Di Biase, Mariaelena; Valerio, Francesca; Lavermicocca, Paola; Sisto, Angelo

    2015-03-16

    Fifty-four spore-forming bacterial strains isolated from bread ingredients and bread, mainly belonging to the genus Bacillus (including Bacillus cereus), together with 11 reference strains were investigated to evaluate their cytotoxic potential and heat survival in order to ascertain if they could represent a risk for consumer health. Therefore, we performed a screening test of cytotoxic activity on HT-29 cells using bacterial culture filtrates after growing bacterial cells in Brain Heart Infusion medium and in the bread-based medium Bread Extract Broth (BEB). Moreover, immunoassays and PCR analyses, specifically targeting already known toxins and related genes of B. cereus, as well as a heat spore inactivation assay were carried out. Despite of strain variability, the results clearly demonstrated a high cytotoxic activity of B. cereus strains, even if for most of them it was significantly lower in BEB medium. Cytotoxic activity was also detected in 30% of strains belonging to species different from B. cereus, although, with a few exceptions (e.g. Bacillus simplex N58.2), it was low or very low. PCR analyses detected the presence of genes involved in the production of NHE, HBL or CytK toxins in B. cereus strains, while genes responsible for cereulide production were not detected. Production of NHE and HBL toxins was also confirmed by specific immunoassays only for B. cereus strains even if PCR analyses revealed the presence of related toxin genes also in some strains of other species. Viable spore count was ascertained after a heat treatment simulating the bread cooking process. Results indicated that B. amyloliquefaciens strains almost completely survived the heat treatment showing less than 2 log-cycle reductions similarly to two strains of B. cereus group III and single strains belonging to Bacillus subtilis, Bacillus mojavensis and Paenibacillus spp. Importantly, spores from strains of the B. cereus group IV exhibited a thermal resistance markedly lower than B

  15. Live cell imaging of germination and outgrowth of individual Bacillus subtilis spores; the effect of heat stress quantitatively analyzed with SporeTracker

    NARCIS (Netherlands)

    Pandey, R.; ter Beek, A.; Vischer, N.O.E.; Smelt, J.P.P.M.; Brul, S.; Manders, E.M.M.

    2013-01-01

    Spore-forming bacteria are a special problem for the food industry as some of them are able to survive preservation processes. Bacillus spp. spores can remain in a dormant, stress resistant state for a long period of time. Vegetative cells are formed by germination of spores followed by a more

  16. Inactivation dynamics of 222 nm krypton-chlorine excilamp irradiation on Gram-positive and Gram-negative foodborne pathogenic bacteria.

    Science.gov (United States)

    Kang, Jun-Won; Kim, Sang-Soon; Kang, Dong-Hyun

    2018-07-01

    The object of this study was to elucidate the bactericidal mechanism of a 222 nm Krypton Chlorine (KrCl) excilamp compared with that of a 254 nm Low Pressure mercury (LP Hg) lamp. The KrCl excilamp had higher bactericidal capacity against Gram-positive pathogenic bacteria (Staphylococcus aureus and L. monocytogenes) and Gram-negative pathogenic bacteria (S. Typhimurium and E. coli O157:H7) than did the LP Hg lamp when cell suspensions in PBS were irradiated with each type of UV lamp. It was found out that the KrCl excilamp induced cell membrane damage as a form of depolarization. From the study of respiratory chain dehydrogenase activity and the lipid peroxidation assay, it was revealed that cell membrane damage was attributed to inactivation of enzymes related to generation of membrane potential and occurrence of lipid peroxidation. Direct absorption of UV radiation which led to photoreaction through formation of an excited state was one of the causes inducing cell damage. Additionally, generation of ROS and thus occurrence of secondary damage can be another cause. The LP Hg lamp only induced damage to DNA but not to other components such as lipids or proteins. This difference was derived from differences of UV radiation absorption by cellular materials. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Tribolium castaneum defensins are primarily active against Gram-positive bacteria

    Czech Academy of Sciences Publication Activity Database

    Tonk, M.; Knorr, E.; Cabezas-Cruz, A.; Valdés, James J.; Kollewe, C.; Vilcinskas, A.

    2015-01-01

    Roč. 132, NOV 2015 (2015), s. 208-215 ISSN 0022-2011 R&D Projects: GA MŠk(CZ) EE2.3.30.0032 Institutional support: RVO:60077344 Keywords : Antimicrobial peptides * Defensin * Innate immunity * Insects * Tribolium castaneum * Gram-positive bacteria Subject RIV: EI - Biotechnology ; Bionics Impact factor: 2.198, year: 2015

  18. Quantification of Nonproteolytic Clostridium botulinum Spore Loads in Food Materials.

    Science.gov (United States)

    Barker, Gary C; Malakar, Pradeep K; Plowman, June; Peck, Michael W

    2016-01-04

    We have produced data and developed analysis to build representations for the concentration of spores of nonproteolytic Clostridium botulinum in materials that are used during the manufacture of minimally processed chilled foods in the United Kingdom. Food materials are categorized into homogenous groups which include meat, fish, shellfish, cereals, fresh plant material, dairy liquid, dairy nonliquid, mushroom and fungi, and dried herbs and spices. Models are constructed in a Bayesian framework and represent a combination of information from a literature survey of spore loads from positive-control experiments that establish a detection limit and from dedicated microbiological tests for real food materials. The detection of nonproteolytic C. botulinum employed an optimized protocol that combines selective enrichment culture with multiplex PCR, and the majority of tests on food materials were negative. Posterior beliefs about spore loads center on a concentration range of 1 to 10 spores kg(-1). Posterior beliefs for larger spore loads were most significant for dried herbs and spices and were most sensitive to the detailed results from control experiments. Probability distributions for spore loads are represented in a convenient form that can be used for numerical analysis and risk assessments. Copyright © 2016 Barker et al.

  19. Hydrothermal vents in Lake Tanganyika harbor spore-forming thermophiles with extremely rapid growth

    DEFF Research Database (Denmark)

    Elsgaard, Lars; Prieur, Daniel

    2010-01-01

    A thermophilic anaerobic bacterium was isolated from a sublacustrine hydrothermal vent site in Lake Tanganyika (East Africa) with recorded fluid temperatures of 66–103 °C and pH values of 7.7–8.9. The bacterium (strain TR10) was rod-shaped, about 1 by 5 μm in size, and readily formed distal...... and peptone. The optimum temperature for growth was 60 °C, while minimum and maximum temperatures were 40 and 75 °C. The pH response was alkalitolerant with optimum pH at 7.4 and 8.5 depending on the growth medium. The distinct feature of rapid proliferation and endospore formation may allow the novel...

  20. Alkaliphilus crotonatoxidans sp. nov., a strictly anaerobic, crotonate-dismutating bacterium isolated from a methanogenic environment.

    Science.gov (United States)

    Cao, Xianhua; Liu, Xiaoli; Dong, Xiuzhu

    2003-07-01

    Two bacterial strains were isolated from methanogenic butyrate-oxidizing mixed cultures. The cells were straight to slightly curved, gram-positive rods that were motile by means of multiple flagella and formed endospores. Growth was observed in the temperature range 15-45 degrees C (optimum 37 degrees C) and pH range 5.5-9.0 (optimum pH 7.5). The novel isolates were strictly anaerobic chemo-organotrophs capable of utilizing yeast extract, peptone, tryptone and a variety of sugars and organic acids, but not glucose. None of the accessory electron acceptors tested (elemental sulfur, thiosulfate or fumarate) improved growth, except crotonate, which was dismutated to butyrate and acetate. The G + C content of the DNA of one of the isolates, strain B11-2T, was 30.6 mol%. Phylogenetic analysis based on 16S rDNA sequence similarity between strain B11-2T and some other strictly anaerobic, spore-forming bacteria indicated that the novel isolates represented a species in cluster XI within the low-GC gram-positive bacteria, being most closely related to Alkaliphilus transvaalensis JCM 10712T. DNA-DNA relatedness between strain B11-2T and A. transvaalensis JCM 10712T was 21%. On the basis of physiological and molecular properties, and cellular fatty acid and cell wall compositions, the novel isolates are proposed to represent a novel species of the genus Alkaliphilus, for which the name Alkaliphilus crotonatoxidans is proposed (type strain B11-2T=AS 1.2897T=JCM 11672T).

  1. European surveillance study on antimicrobial susceptibility of Gram-positive anaerobic cocci

    DEFF Research Database (Denmark)

    Brazier, J; Chmelar, D; Dubreuil, L

    2008-01-01

    Gram-positive anaerobic cocci (GPAC) are a heterogeneous group of microorganisms frequently isolated from local and systemic infections. In this study, the antimicrobial susceptibilities of clinical strains isolated in 10 European countries were investigated. After identification of 299 GPAC...

  2. Características morfo-tintoriales en el ciclo celular de Acinetobacter baumannii por los métodos de Gram y 4’, 6-diamidino-2’-fenilindol, dihidrocloruro | Morphological and staining characteristics in cell cycle of Acinetobacter baumannii by the methods of Gram and 4´, 6-diamidino-2´-phenylindole, dihydrochloride

    Directory of Open Access Journals (Sweden)

    Evelin Flores Hernández

    2017-11-01

    Full Text Available Several studies have reported variations in bacterial staining by Gram, which are associated with the content of nucleic acids in the bacterial cell cycle. In order to give continuity to the microscopical studies pertaining to the bacterial cell cycle, the morphological and staining characteristics were evaluated by Gram and 4', 6-diamidino-2'-phenylindole, dihydrochloride (DAPI in the cell cycle of Acinetobacter baumannii. From the synchronic cultures of 4 strains of A. baumannii, the cell cycle was studied incubating them in aerobiosis at 30ºC, taking aliquots every 5 min for 2 h. In turn, the respective extensions were made and stained with Gram and DAPI for their posterior microscopical study. In the statistical analysis Fischer's test was used to associate morphological and the staining characteristics by Gram and DAPI. In 74% of cycle times, the cocoid form predominated and 67% in the negative Gram staining. When determining the mean and standard deviation of bacterial morphological values, it was observed that between 15 and 55 min the bacterium initiates a new cell cycle, decreasing its diameter and length. There was a statistically significant association (p < 0.05 between the lax and compact appearance of the material with the light and intense fluorescent, respectively; likewise, between the strong Gram positive character and the intense fluorescence. It is concluded that in the Gram positive reaction, the DNA is possibly involved and that the purple material of compact and lax aspect observed by Gram staining in the bacterial cytoplasm correspond to the nucleoid and the morphological changes obey to the cellular growth process. These findings contribute to explain the mechanism of Gram staining, as well as its variability and the pleomorphism observed in this bacterial genus.

  3. Detection and differentiation of bacterial spores in a mineral matrix by Fourier transform infrared spectroscopy (FTIR and chemometrical data treatment

    Directory of Open Access Journals (Sweden)

    Brandes Ammann Andrea

    2011-07-01

    Full Text Available Abstract Background Fourier transform infrared spectroscopy (FTIR has been used as analytical tool in chemistry for many years. In addition, FTIR can also be applied as a rapid and non-invasive method to detect and identify microorganisms. The specific and fingerprint-like spectra allow - under optimal conditions - discrimination down to the species level. The aim of this study was to develop a fast and reproducible non-molecular method to differentiate pure samples of Bacillus spores originating from different species as well as to identify spores in a simple matrix, such as the clay mineral, bentonite. Results We investigated spores from pure cultures of seven different Bacillus species by FTIR in reflection or transmission mode followed by chemometrical data treatment. All species investigated (B. atrophaeus, B. brevis, B. circulans, B. lentus, B. megaterium, B. subtilis, B. thuringiensis are typical aerobic soil-borne spore formers. Additionally, a solid matrix (bentonite and mixtures of benonite with spores of B. megaterium at various wt/wt ratios were included in the study. Both hierarchical cluster analysis and principal component analysis of the spectra along with multidimensional scaling allowed the discrimination of different species and spore-matrix-mixtures. Conclusions Our results show that FTIR spectroscopy is a fast method for species-level discrimination of Bacillus spores. Spores were still detectable in the presence of the clay mineral bentonite. Even a tenfold excess of bentonite (corresponding to 2.1 × 1010 colony forming units per gram of mineral matrix still resulted in an unambiguous identification of B. megaterium spores.

  4. Outcomes of single organism peritonitis in peritoneal dialysis: gram negatives versus gram positives in the Network 9 Peritonitis Study.

    Science.gov (United States)

    Bunke, C M; Brier, M E; Golper, T A

    1997-08-01

    The use of the "peritonitis rate" in the management of patients undergoing peritoneal dialysis is assuming importance in comparing the prowess of facilities, care givers and new innovations. For this to be a meaningful outcome measure, the type of infection (causative pathogen) must have less clinical significance than the number of infections during a time interval. The natural history of Staphylococcus aureus, pseudomonas, and fungal peritonitis would not support that the outcome of an episode of peritonitis is independent of the causative pathogen. Could this concern be extended to other more frequently occurring pathogens? To address this, the Network 9 Peritonitis Study identified 530 episodes of single organism peritonitis caused by a gram positive organism and 136 episodes caused by a single non-pseudomonal gram negative (NPGN) pathogen. Coincidental soft tissue infections (exit site or tunnel) occurred equally in both groups. Outcomes of peritonitis were analyzed by organism classification and by presence or absence of a soft tissue infection. NPGN peritonitis was associated with significantly more frequent catheter loss, hospitalization, and technique failure and was less likely to resolve regardless of the presence or absence of a soft tissue infection. Hospitalization and death tended to occur more frequently with enterococcal peritonitis than with other gram positive peritonitis. The outcomes in the NPGN peritonitis group were significantly worse (resolution, catheter loss, hospitalization, technique failure) compared to coagulase negative staphylococcal or S. aureus peritonitis, regardless of the presence or absence of a coincidental soft tissue infection. Furthermore, for the first time, the poor outcomes of gram negative peritonitis are shown to be independent of pseudomonas or polymicrobial involvement or soft tissue infections. The gram negative organism appears to be the important factor. In addition, the outcome of peritonitis caused by S. aureus

  5. High positive predictive value of Gram stain on catheter-drawn blood samples for the diagnosis of catheter-related bloodstream infection in intensive care neonates.

    Science.gov (United States)

    Deleers, M; Dodémont, M; Van Overmeire, B; Hennequin, Y; Vermeylen, D; Roisin, S; Denis, O

    2016-04-01

    Catheter-related bloodstream infections (CRBSIs) remain a leading cause of healthcare-associated infections in preterm infants. Rapid and accurate methods for the diagnosis of CRBSIs are needed in order to implement timely and appropriate treatment. A retrospective study was conducted during a 7-year period (2005-2012) in the neonatal intensive care unit of the University Hospital Erasme to assess the value of Gram stain on catheter-drawn blood samples (CDBS) to predict CRBSIs. Both peripheral samples and CDBS were obtained from neonates with clinically suspected CRBSI. Gram stain, automated culture and quantitative cultures on blood agar plates were performed for each sample. The paired quantitative blood culture was used as the standard to define CRBSI. Out of 397 episodes of suspected CRBSIs, 35 were confirmed by a positive ratio of quantitative culture (>5) or a colony count of CDBS culture >100 colony-forming units (CFU)/mL. All but two of the 30 patients who had a CDBS with a positive Gram stain were confirmed as having a CRBSI. Seven patients who had a CDBS with a negative Gram stain were diagnosed as CRBSI. The sensitivity, specificity, positive predictive value and negative predictive value of Gram stain on CDBS were 80, 99.4, 93.3 and 98.1 %, respectively. Gram staining on CDBS is a viable method for rapidly (<1 h) detecting CRBSI without catheter withdrawal.

  6. Akkermansia glycaniphila sp. nov., an anaerobic mucin-degrading bacterium isolated from reticulated python faeces.

    Science.gov (United States)

    Ouwerkerk, Janneke P; Aalvink, Steven; Belzer, Clara; de Vos, Willem M

    2016-11-01

    A Gram-stain-negative, non-motile, strictly anaerobic, oval-shaped, non-spore-forming bacterium (strain PytT) was isolated from reticulated python faeces. Strain PytT was capable of using mucin as sole carbon, energy and nitrogen source. Cells could grow singly, in pairs, and were also found to aggregate. Scanning electron microscopy revealed the presence of filamentous structures connecting individual bacterial cells. Strain PytT could grow on a limited number of single sugars, including N-acetylglucosamine, N-acetylgalactosamine, glucose, lactose and galactose, but only when a plentiful protein source was provided. Phylogenetic analysis based on 16S rRNA gene sequencing showed strain PytT to belong to the Verrucomicrobiae class I, family Akkermansiaceae, genus Akkermansia, with Akkermansia muciniphila MucT as the closest relative (94.4 % sequence similarity). DNA-DNA hybridization revealed low relatedness of 28.3 % with A. muciniphila MucT. The G+C content of DNA from strain PytT was 58.2 mol%. The average nucleotide identity (ANI) of the genome of strain PytT compared to the genome of strain MucT was 79.7 %. Chemotaxonomic data supported the affiliation of strain PytT to the genus Akkermansia. Based on phenotypic, phylogenetic and genetic characteristics, strain PytT represents a novel species of the genus Akkermansia, for which the name Akkermansia glycaniphila sp. nov. is proposed. The type strain is PytT (=DSM 100705T=CIP 110913T).

  7. Methods for Confirming the Gram Reaction of Gram-variable Bacillus Species Isolated from Tobacco

    Directory of Open Access Journals (Sweden)

    Morin A

    2014-12-01

    Full Text Available Bacillus is a predominant genus of bacteria isolated from tobacco. The Gram stain is the most commonly used and most important of all diagnostic staining techniques in microbiology. In order to help confirm the Gram positivity of Bacillus isolates from tobacco, three methods using the chemical differences of the cell wall and membrane of Gram-positive and Gram-negative bacteria were investigated: the KOH (potassium hydroxide, the LANA (L-alanine-4-nitroanilide, and the vancomycin susceptibility tests. When colonies of Gram-negative bacteria are treated with 3% KOH solution, a slimy suspension is produced, probably due to destruction of the cell wall and liberation of deoxyribonucleic acid (DNA. Gram-positive cell walls resist KOH treatment. The LANA test reveals the presence of a cell wall aminopeptidase that hydrolyzes the L-alanine-4-nitroanilide in Gram-negative bacteria. This enzyme is absent in Gram-positive bacteria. Vancomycin is a glycopeptide antibiotic inhibiting the cell wall peptido-glycan synthesis of Gram-positive microorganisms. Absence of lysis with KOH, absence of hydrolysis of LANA, and susceptibility to vancomycin were used with the Gram reaction to confirm the Gram positivity of various Bacillus species isolated from tobacco. B. laevolacticus excepted, all Bacillus species tested showed negative reactions to KOH and LANA tests, and all species were susceptible to vancomycin (5 and 30 µg.

  8. Antibacterial Activity of Different Plant Extracts and Phenolic Phytochemicals Tested on Paenibacillus Larvae Bacteria

    Directory of Open Access Journals (Sweden)

    Liviu Mărghitaş

    2011-10-01

    Full Text Available Paenibacillus larvae, a Gram-positive and spore-forming bacterium is responsible for American foulbrood disease inbees. The antimicrobial activity of different plant extracts and phenolic phytochemical was evaluated onPaenibacillus larvae bacteria. In addition possible correlation with antioxidant activity of the same plant extracts wasstudied. Extracts of the following plants were utilized: Achillea millefolium (yarrow, Ocimum basilicum (basil,Thymus vulgaris (thyme and Urtica dioica (nettle. The extracts that showed antimicrobial activity were later testedto determine the Minimal Inhibitory Concentration (MIC. Although nettle present the lowest polyphenolic contentcompared with the other plant extracts, exhibit the highest antimicrobial activity, measured as the inhibition zoneusing Mueller-Hinton agar plates. Basil presented both polyphenolic content and antimicrobial activity at higherlevels, while thyme had the lowest antimicrobial activity, even it present high amount of polyphenols.

  9. Emergence of a New Population of Rathayibacter toxicus: An Ecologically Complex, Geographically Isolated Bacterium

    OpenAIRE

    Arif, Mohammad; Busot, Grethel Y.; Mann, Rachel; Rodoni, Brendan; Liu, Sanzhen; Stack, James P.

    2016-01-01

    Rathayibacter toxicus is a gram-positive bacterium that infects the floral parts of several Poaceae species in Australia. Bacterial ooze is often produced on the surface of infected plants and bacterial galls are produced in place of seed. R. toxicus is a regulated plant pathogen in the U.S. yet reliable detection and diagnostic tools are lacking. To better understand this geographically-isolated plant pathogen, genetic variation as a function of geographic location, host species, and date of...

  10. Optimization of linezolid treatment regimens for Gram-positive bacterial infections based on pharmacokinetic/pharmacodynamic analysis.

    Science.gov (United States)

    Yang, Minjie; Zhang, Jing; Chen, Yuancheng; Liang, Xiaoyu; Guo, Yan; Yu, Jicheng; Zhu, Demei; Zhang, Yingyuan

    2017-01-01

    To optimize linezolid treatment regimens for Gram-positive bacterial infections based on pharmacokinetic/pharmacodynamic analysis. The minimum inhibitory concentration (MIC) distribution of 572 Gram-positive strains from patients with clinically confirmed infections was analyzed. Using the Monte Carlo simulation method, the cumulative fraction of response and probability of target attainment were determined for linezolid regimens of 600 mg q.12h and q.8h Results: Linezolid dosage of 600 mg q.12h yielded >90% cumulative fraction of response and probability of target attainment for staphylococcal infections with an MIC of ≤1 mg/l, enterococcal infections with higher MIC values required 600 mg q.8h. Linezolid 600 mg q.12h is still the clinically recommended empirical dosage for Gram-positive bacterial infections. However, as bacterial MICs increase, 600 mg q.8h may be required to achieve better efficacy.

  11. Thermincola carboxydiphila gen. nov., sp. nov., a novel anaerobic, carboxydotrophic, hydrogenogenic bacterium from a hot spring of the Lake Baikal area.

    Science.gov (United States)

    Sokolova, Tatyana G; Kostrikina, Nadezhda A; Chernyh, Nikolai A; Kolganova, Tatjana V; Tourova, Tatjana P; Bonch-Osmolovskaya, Elizaveta A

    2005-09-01

    A novel anaerobic, thermophilic, alkalitolerant bacterium, strain 2204(T), was isolated from a hot spring of the Baikal Lake region. The cells of strain 2204(T) were straight rods of variable length, Gram-positive with an S-layer, motile with one to two lateral flagella, and often formed aggregates of 3-15 cells. The isolate was shown to be an obligate anaerobe oxidizing CO and producing equimolar quantities of H(2) and CO(2) according to the equation CO+H(2)O-->CO(2)+H(2). No organic substrates were used as energy sources. For lithotrophic growth on CO, 0.2 g acetate or yeast extract l(-1) was required but did not support growth in the absence of CO. Growth was observed in the temperature range 37-68 degrees C, the optimum being 55 degrees C. The pH range for growth was 6.7-9.5, the optimum pH being 8.0. The generation time under optimal conditions was 1.3 h. The DNA G+C content was 45 mol%. Penicillin, erythromycin, streptomycin, rifampicin, vancomycin and tetracycline completely inhibited both growth and CO utilization by strain 2204(T). Thus, isolate 2204(T) was found to be the first known moderately thermophilic and alkalitolerant H(2)-producing anaerobic carboxydotroph. The novel bacterium fell within the cluster of the family Peptococcaceae within the low-G+C-content Gram-positive bacteria, where it formed a separate branch. On the basis of morphological, physiological and phylogenetic features, strain 2204(T) should be assigned to a novel genus and species, for which the name Thermincola carboxydiphila gen. nov., sp. nov. is proposed. The type strain is strain 2204(T) (=DSM 17129(T)=VKM B-2283(T)=JCM 13258(T)).

  12. Electrochemical reduction of oxygen catalyzed by a wide range of bacteria including Gram-positive

    Energy Technology Data Exchange (ETDEWEB)

    Cournet, Amandine [Universite de Toulouse, UPS, LU49, Adhesion Bacterienne et Formation de Biofilms, 35 chemin des Maraichers, 31 062 Toulouse cedex 09 (France); Laboratoire de Genie Chimique CNRS, Universite de Toulouse, 4 allee Emile Monso, BP 84234, 31432 Toulouse cedex 04 (France); Delia, Marie-Line; Bergel, Alain [Laboratoire de Genie Chimique CNRS, Universite de Toulouse, 4 allee Emile Monso, BP 84234, 31432 Toulouse cedex 04 (France); Roques, Christine; Berge, Mathieu [Universite de Toulouse, UPS, LU49, Adhesion Bacterienne et Formation de Biofilms, 35 chemin des Maraichers, 31 062 Toulouse cedex 09 (France)

    2010-04-15

    Most bacteria known to be electrochemically active have been harvested in the anodic compartments of microbial fuel cells (MFCs) and are able to use electrodes as electron acceptors. The reverse phenomenon, i.e. using solid electrodes as electron donors, is not so widely studied. To our knowledge, most of the electrochemically active bacteria are Gram-negative. The present study implements a transitory electrochemical technique (cyclic voltammetry) to study the microbial catalysis of the electrochemical reduction of oxygen. It is demonstrated that a wide range of aerobic and facultative anaerobic bacteria are able to catalyze oxygen reduction. Among these electroactive bacteria, several were Gram-positive. The transfer of electrons was direct since no activity was obtained with the filtrate. These findings, showing a widespread property among bacteria including Gram-positive ones, open new and interesting routes in the field of electroactive bacteria research. (author)

  13. Absence of transient elevated uv resistance during germination of Bacillus subtilis spores lacking small, acid-soluble spore proteins α and β

    International Nuclear Information System (INIS)

    Setlow, B.; Setlow, P.

    1988-01-01

    Dormant spores of various Bacillus species are much more resistant to UV irradiation than are the corresponding vegetative cells. This elevated spore UV resistance appears to have two causes. First, UV irradiation of spores does not produce the pyrimidine dimers formed in vegetative-cell DNA, but rather produces several other photoproducts, the most predominant of which is termed the spore photoproduct, a 5-thyminyl-5,6-dihydrothymine adduct (1, 10). Second, spores have at least two mechanisms which efficiently repair this spore photoproduct during spore germination, including one which monomerizes the adduct back to two thymines. This study shows that germinating spores of bacillus subtilis mutants which lack small, acid-soluble spore proteins α and β did not exhibit the transient elevated UV resistance seen during germination of wild-type spores

  14. Noncontiguous finished genome sequence and description of Paenibacillus ihumii sp. nov. strain AT5

    Directory of Open Access Journals (Sweden)

    A.H. Togo

    2016-03-01

    Full Text Available Paenibacillus ihumii sp. nov. strain AT5 (= CSUR 1981 = DSM 100664 is the type strain of P. ihumii. This bacterium was isolated from a stool sample from a morbidly obese French patient using the culturomics approach. The genome of this Gram-negative, facultative anaerobic, motile and spore-forming bacillus is 5 924 686 bp long. Genomic analysis identified 253 (5% of 3812 genes as ORFans and at least 2599 (50.03% of 5194 orthologous proteins not shared with the closest phylogenetic species.

  15. Human anthrax as a re-emerging disease.

    Science.gov (United States)

    Doganay, Mehmet; Demiraslan, Hayati

    2015-01-01

    Anthrax is primarily a disease of herbivores and the etiological agent is B. anthracis which is a gram-positive, aerobic, spore-forming, and rod shaped bacterium. Bacillus anthracis spores are highly resistant to heat, pressure, ultraviolet and ionizing radiation, chemical agents and disinfectants. For these reasons, B. anthracis spores are an attractive choice as biological agents for the use of bioweapon and/or bioterrorism. Soil is the main reservoir for the infectious agent. The disease most commonly affects wild and domestic mammals. Human are secondarily infected by contact with infected animals and contaminated animal products or directly expose to B. anthracis spores. Anthrax occurs worldwide. This infection is still endemic or hyperendemic in both animals and humans in some part of areas of the world; particularly in Middle East, West Africa, Central Asia, some part of India, South America. However, some countries are claiming free of anthrax, and anthrax has become a re-emerging disease in western countries with the intentional outbreak. Currently, anthrax is classified according to its setting as (1) naturally occurring anthrax, (2) bioterrorism-related anthrax. Vast majority of human anthrax are occurring as naturally occurring anthrax in the world. It is also a threaten disease for western countries. The aim of this paper is to review the relevant patents, short historical perspective, microbiological and epidemiological features, clinical presentations and treatment.

  16. Recovery of vancomycin-resistant gram-positive cocci from children.

    OpenAIRE

    Green, M; Wadowsky, R M; Barbadora, K

    1990-01-01

    A cross-sectional survey of vancomycin-resistant gram-positive cocci (VRGPC) in the feces of children was initiated after several bacteremic infections with these organisms occurred at our hospital. A selective medium consisting of colistin-nalidixic acid agar, 5% sheep blood, vancomycin (5 mg/liter), and amphotericin B (8 mg/liter) was developed to isolate VRGPC. A single stool specimen submitted to the clinical microbiology laboratory from each of 48 patients was inoculated onto the medium....

  17. The regulated synthesis of a Bacillus anthracis spore coat protein that affects spore surface properties.

    Science.gov (United States)

    Aronson, A; Goodman, B; Smith, Z

    2014-05-01

    Examine the regulation of a spore coat protein and the effects on spore properties. A c. 23 kDa band in coat/exosporial extracts of Bacillus anthracis Sterne spores varied in amount depending upon the conditions of sporulation. It was identified by MALDI as a likely orthologue of ExsB of Bacillus cereus. Little if any was present in an exosporial preparation with a location to the inner coat/cortex region established by spore fractionation and immunogold labelling of electron micrograph sections. Because of its predominant location in the inner coat, it has been renamed Cotγ. It was relatively deficient in spores produced at 37°C and when acidic fermentation products were produced a difference attributable to transcriptional regulation. The deficiency or absence of Cotγ resulted in a less robust exosporium positioned more closely to the coat. These spores were less hydrophobic and germinated somewhat more rapidly. Hydrophobicity and appearance were rescued in the deletion strain by introduction of the cotγ gene. The deficiency or lack of a protein largely found in the inner coat altered spore hydrophobicity and surface appearance. The regulated synthesis of Cotγ may be a paradigm for other spore coat proteins with unknown functions that modulate spore properties in response to environmental conditions. © 2014 The Society for Applied Microbiology.

  18. Metabolic versatility of Gram-positive microbial isolates from contaminated river sediments

    International Nuclear Information System (INIS)

    Narancic, Tanja; Djokic, Lidija; Kenny, Shane T.; O’Connor, Kevin E.; Radulovic, Vanja; Nikodinovic-Runic, Jasmina; Vasiljevic, Branka

    2012-01-01

    Highlights: ► Thirty-four isolated Gram-positive bacteria could degrade wide range of aromatic pollutants. ► Nine isolates could grow in the presence of extremely high levels of heavy metals. ► Twelve isolates accumulated polyphosphate, 3 polyhydroxybutyrate, 4 exopolysaccharides. ► The incidence of multiple antibiotic resistance markers among isolates was low. - Abstract: Gram-positive bacteria from river sediments affected by the proximity of a petrochemical industrial site were isolated and characterized with respect to their ability to degrade a wide range of aromatic compounds. In this study we identified metabolically diverse Gram-positive bacteria capable of growth on wide range aromatic compounds in the presence of heavy metals and with the ability to accumulate biopolymers. Thirty-four isolates that were able to use 9 or more common aromatic pollutants, such as benzene, biphenyl, naphthalene etc. as a sole source of carbon and energy included members of Bacillus, Arthrobacter, Rhodococcus, Gordonia, Streptomyces, and Staphylococcus genus. Rhodococcus sp. TN105, Gordonia sp. TN103 and Arthrobacter sp. TN221 were identified as novel strains. Nine isolates were able to grow in the presence of one or more metals (mercury, cadmium, nickel) at high concentration (100 mM). Seven isolates could degrade 15 different aromatic compounds and could grow in the presence of one or more heavy metals. Two of these isolates were resistant to multiple antibiotics including erythromycin and nalidixic acid. One third of isolates could accumulate at least one biopolymer. Twelve isolates (mainly Bacillus sp. and Arthrobacter sp.) accumulated polyphosphate, 3 Bacillus sp. accumulated polyhydroxybutyrate, while 4 isolates could accumulate exopolysaccharides.

  19. A Flexible Binding Site Architecture Provides New Insights into CcpA Global Regulation in Gram-Positive Bacteria.

    Science.gov (United States)

    Yang, Yunpeng; Zhang, Lu; Huang, He; Yang, Chen; Yang, Sheng; Gu, Yang; Jiang, Weihong

    2017-01-24

    poorly explored for the diversity of CcpA-mediated catabolite regulation. Here, we discovered a novel flexible CcpA-binding site architecture (cre var ) that is highly variable in both length and base composition but follows certain principles, providing new insights into how CcpA can differentially recognize a variety of target genes to form a complicated regulatory network. A comprehensive search further revealed the wide distribution of cre var sites in Gram-positive bacteria, indicating it may have a universal function. This finding is the first to characterize such a highly flexible transcription factor-binding site architecture, which would be valuable for deeper understanding of CcpA-mediated global catabolite regulation in bacteria. Copyright © 2017 Yang et al.

  20. Exact closed-form expression for the inverse moments of one-sided correlated Gram matrices

    KAUST Repository

    Elkhalil, Khalil

    2016-08-15

    In this paper, we derive a closed-form expression for the inverse moments of one sided-correlated random Gram matrices. Such a question is mainly motivated by applications in signal processing and wireless communications for which evaluating this quantity is a question of major interest. This is for instance the case of the best linear unbiased estimator, in which the average estimation error corresponds to the first inverse moment of a random Gram matrix.

  1. Exact closed-form expression for the inverse moments of one-sided correlated Gram matrices

    KAUST Repository

    Elkhalil, Khalil; Kammoun, Abla; Al-Naffouri, Tareq Y.; Alouini, Mohamed-Slim

    2016-01-01

    In this paper, we derive a closed-form expression for the inverse moments of one sided-correlated random Gram matrices. Such a question is mainly motivated by applications in signal processing and wireless communications for which evaluating this quantity is a question of major interest. This is for instance the case of the best linear unbiased estimator, in which the average estimation error corresponds to the first inverse moment of a random Gram matrix.

  2. Over a Decade of recA and tly Gene Sequence Typing of the Skin Bacterium Propionibacterium acnes: What Have We Learnt?

    Directory of Open Access Journals (Sweden)

    Andrew McDowell

    2017-12-01

    Full Text Available The Gram-positive, anaerobic bacterium Propionibacterium acnes forms part of the normal microbiota on human skin and mucosal surfaces. While normally associated with skin health, P. acnes is also an opportunistic pathogen linked with a range of human infections and clinical conditions. Over the last decade, our knowledge of the intraspecies phylogenetics and taxonomy of this bacterium has increased tremendously due to the introduction of DNA typing schemes based on single and multiple gene loci, as well as whole genomes. Furthermore, this work has led to the identification of specific lineages associated with skin health and human disease. In this review we will look back at the introduction of DNA sequence typing of P. acnes based on recA and tly loci, and then describe how these methods provided a basic understanding of the population genetic structure of the bacterium, and even helped characterize the grapevine-associated lineage of P. acnes, known as P. acnes type Zappe, which appears to have undergone a host switch from humans-to-plants. Particular limitations of recA and tly sequence typing will also be presented, as well as a detailed discussion of more recent, higher resolution, DNA-based methods to type P. acnes and investigate its evolutionary history in greater detail.

  3. Silver-doped manganese dioxide and trioxide nanoparticles inhibit both gram positive and gram negative pathogenic bacteria.

    Science.gov (United States)

    Kunkalekar, R K; Prabhu, M S; Naik, M M; Salker, A V

    2014-01-01

    Palladium, ruthenium and silver-doped MnO2 and silver doped Mn2O3 nanoparticles were synthesized by simple co-precipitation technique. SEM-TEM analysis revealed the nano-size of these synthesized samples. XPS data illustrates that Mn is present in 4+ and 3+ oxidation states in MnO2 and Mn2O3 respectively. Thermal analysis gave significant evidence for the phase changes with increasing temperature. Antibacterial activity of these synthesized nanoparticles on three Gram positive bacterial cultures (Staphylococcus aureus ATCC 6538, Streptococcus epidermis ATCC 12228, Bacillus subtilis ATCC 6633) and three Gram negative cultures (Escherichia coli ATCC 8739, Salmonella abony NCTC 6017 and Klebsiella pneumoniae ATCC 1003) was investigated using a disc diffusion method and live/dead assay. Only Ag-doped MnO2 and Ag-doped Mn2O3 nanoparticles showed antibacterial property against all six-test bacteria but Ag-doped MnO2 was found to be more effective than Ag-doped Mn2O3. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Isolation and Characterization of Acetate-Utilizing Anaerobes from a Freshwater Sediment.

    Science.gov (United States)

    Scholten, J.C.M.; Stams, A.J.M.

    2000-12-01

    Acetate-degrading anaerobic microorganisms in freshwater sediment were quantified by the most probable number technique. From the highest dilutions a methanogenic, a sulfate-reducing, and a nitrate-reducing microorganism were isolated with acetate as substrate. The methanogen (culture AMPB-Zg) was non-motile and rod-shaped with blunted ends (0.5-1 mm x 3-4 mm long). Doubling times with acetate at 30-35 degrees C were 5.6-8.1 days. The methanogen grew only on acetate. Analysis of the 16S rRNA sequence showed that AMPB-Zg is closely related to Methanosaeta concilii. The isolated sulfate-reducing bacterium (strain ASRB-Zg) was rod-shaped with pointed ends (0.5-0.7 mm x 1.5-3.5 mm long), weakly motile, spore forming, and gram positive. At the optimum growth temperature of 30 degrees C the doubling times with acetate were 3.9-5.3 days. The bacterium grew on a range of organic acids, such as acetate, butyrate, fumarate, and benzoate, but did not grow autotrophically with H2, CO2, and sulfate. The closest relative of strain ASRB-Zg is Desulfotomaculum acetoxidans. The nitrate-reducing bacterium (strain ANRB-Zg) was rod-shaped (0.5-0.7 mm x 0.7-1 mm long), weakly motile, and gram negative. Optimum growth with acetate occurred at 20-25 degrees C. The bacterium grew on a range of organic substrates, such as acetate, butyrate, lactate, and glucose, and did grow autotrophically with H2, CO2, and oxygen but not with nitrate. In the presence of acetate and nitrate, thiosulfate was oxidized to sulfate. Phylogenetically, the closest relative of strain ANRB-Zg is Variovorax paradoxus.

  5. Identification of aerobic Gram-positive bacilli by use of Vitek MS.

    Science.gov (United States)

    Navas, Maria; Pincus, David H; Wilkey, Kathy; Sercia, Linda; LaSalvia, Margaret; Wilson, Deborah; Procop, Gary W; Richter, Sandra S

    2014-04-01

    The accuracy of Vitek MS mass spectrometric identifications was assessed for 206 clinically significant isolates of aerobic Gram-positive bacilli representing 20 genera and 38 species. The Vitek MS identifications were correct for 85% of the isolates (56.3% to the species level, 28.6% limited to the genus level), with misidentifications occurring for 7.3% of the isolates.

  6. In vitro activities of dalbavancin and nine comparator agents against anaerobic gram-positive species and corynebacteria.

    Science.gov (United States)

    Goldstein, Ellie J C; Citron, Diane M; Merriam, C Vreni; Warren, Yumi; Tyrrell, Kerin; Fernandez, Helen T

    2003-06-01

    Dalbavancin is a novel semisynthetic glycopeptide with enhanced activity against gram-positive species. Its comparative in vitro activities and those of nine comparator agents, including daptomycin, vancomycin, linezolid, and quinupristin-dalfopristin, against 290 recent gram-positive clinical isolates strains, as determined by the NCCLS agar dilution method, were studied. The MICs of dalbavancin at which 90% of various isolates tested were inhibited were as follows: Actinomyces spp., 0.5 microg/ml; Clostridium clostridioforme, 8 microg/ml; C. difficile, 0.25 microg/ml; C. innocuum, 0.25 microg/ml; C. perfringens, 0.125 microg/ml; C. ramosum, 1 microg/ml; Eubacterium spp., 1 microg/ml; Lactobacillus spp., >32 microg/ml, Propionibacterium spp., 0.5 microg/ml; and Peptostreptococcus spp., 0.25 microg/ml. Dalbavancin was 1 to 3 dilutions more active than vancomycin against most strains. Dalbavancin exhibited excellent activity against gram-positive strains tested and warrants clinical evaluation.

  7. Complete genome sequence of Beutenbergia cavernae type strain (HKI 0122T)

    Energy Technology Data Exchange (ETDEWEB)

    Land, Miriam; Pukall, Rudiger; Abt, Birte; Goker, Markus; Rohde, Manfred; Glavina Del Rio, Tijana; Tice, Hope; Copeland, Alex; Cheng, Jan-Fang; Lucas, Susan; Chen, Feng; Nolan, Matt; Bruce, David; Goodwin, Lynne; Pitluck, Sam; Ivanova, Natalia; Mavrommatis, Konstantinos; Ovchinnikova, Galina; Pati, Amrita; Chen, Amy; Palaniappan, Krishna; Hauser, Loren; Chang, Yun-Juan; Jefferies, Cynthia C.; Saunders, Elizabeth; Brettin, Thomas; Detter, John C.; Han, Cliff; Chain, Patrick; Bristow, James; Eisen, Jonathan A.; Markowitz, Victor; Hugenholtz, Philip; Kyrpides, Nikos C.; Klenk, Hans-Peter; Lapidus, Alla

    2009-05-20

    Beutenbergia cavernae (Groth et al. 1999) is the type species of the genus and is of phylogenetic interest because of its isolated location in the actinobacterial suborder Micrococcineae. B. cavernae HKI 0122T is a Gram-positive, non-motile, non-spore-forming bacterium isolated from a cave in Guangxi (China). B. cavernae grows best under aerobic conditions and shows a rod-coccus growth cycle. Its cell wall peptidoglycan contains the diagnostic L-lysine - L-glutamate interpeptide bridge. Here we describe the features of this organism, together with the complete genome sequence, and annotation. This is the first completed genome sequence from the poorly populated micrococcineal family Beutenbergiaceae, and this 4,669,183 bp long single replicon genome with its 4225 protein-coding and 53 RNA genes is part of the Genomic Encyclopedia of Bacteria and Archaea project.

  8. Impact of Serine/Threonine Protein Kinases on the Regulation of Sporulation in Bacillus subtilis.

    Science.gov (United States)

    Pompeo, Frédérique; Foulquier, Elodie; Galinier, Anne

    2016-01-01

    Bacteria possess many kinases that catalyze phosphorylation of proteins on diverse amino acids including arginine, cysteine, histidine, aspartate, serine, threonine, and tyrosine. These protein kinases regulate different physiological processes in response to environmental modifications. For example, in response to nutritional stresses, the Gram-positive bacterium Bacillus subtilis can differentiate into an endospore; the initiation of sporulation is controlled by the master regulator Spo0A, which is activated by phosphorylation. Spo0A phosphorylation is carried out by a multi-component phosphorelay system. These phosphorylation events on histidine and aspartate residues are labile, highly dynamic and permit a temporal control of the sporulation initiation decision. More recently, another kind of phosphorylation, more stable yet still dynamic, on serine or threonine residues, was proposed to play a role in spore maintenance and spore revival. Kinases that perform these phosphorylation events mainly belong to the Hanks family and could regulate spore dormancy and spore germination. The aim of this mini review is to focus on the regulation of sporulation in B. subtilis by these serine and threonine phosphorylation events and the kinases catalyzing them.

  9. Dose-Dependent Antimicrobial Activity of Silver Nanoparticles on Polycaprolactone Fibers against Gram-Positive and Gram-Negative Bacteria

    Directory of Open Access Journals (Sweden)

    Erick Pazos-Ortiz

    2017-01-01

    Full Text Available The adhesion ability and adaptability of bacteria, coupled with constant use of the same bactericides, have made the increase in the diversity of treatments against infections necessary. Nanotechnology has played an important role in the search for new ways to prevent and treat infections, including the use of metallic nanoparticles with antibacterial properties. In this study, we worked on the design of a composite of silver nanoparticles (AgNPS embedded in poly-epsilon-caprolactone nanofibers and evaluated its antimicrobial properties against various Gram-positive and Gram-negative microorganisms associated with drug-resistant infections. Polycaprolactone-silver composites (PCL-AgNPs were prepared in two steps. The first step consisted in the reduction in situ of Ag+ ions using N,N-dimethylformamide (DMF in tetrahydrofuran (THF solution, and the second step involved the simple addition of polycaprolactone before electrospinning process. Antibacterial activity of PCL-AgNPs nanofibers against E. coli, S. mutans, K. pneumoniae, S. aureus, P. aeruginosa, and B. subtilis was evaluated. Results showed sensibility of E. coli, K. pneumoniae, S. aureus, and P. aeruginosa, but not for B. subtilis and S. mutans. This antimicrobial activity of PCL-AgNPs showed significant positive correlations associated with the dose-dependent effect. The antibacterial property of the PCL/Ag nanofibers might have high potential medical applications in drug-resistant infections.

  10. Adaptation of the spore discharge mechanism in the basidiomycota.

    Directory of Open Access Journals (Sweden)

    Jessica L Stolze-Rybczynski

    Full Text Available Spore discharge in the majority of the 30,000 described species of Basidiomycota is powered by the rapid motion of a fluid droplet, called Buller's drop, over the spore surface. In basidiomycete yeasts, and phytopathogenic rusts and smuts, spores are discharged directly into the airflow around the fungal colony. Maximum discharge distances of 1-2 mm have been reported for these fungi. In mushroom-forming species, however, spores are propelled over much shorter ranges. In gilled mushrooms, for example, discharge distances of <0.1 mm ensure that spores do not collide with opposing gill surfaces. The way in which the range of the mechanism is controlled has not been studied previously.In this study, we report high-speed video analysis of spore discharge in selected basidiomycetes ranging from yeasts to wood-decay fungi with poroid fruiting bodies. Analysis of these video data and mathematical modeling show that discharge distance is determined by both spore size and the size of the Buller's drop. Furthermore, because the size of Buller's drop is controlled by spore shape, these experiments suggest that seemingly minor changes in spore morphology exert major effects upon discharge distance.This biomechanical analysis of spore discharge mechanisms in mushroom-forming fungi and their relatives is the first of its kind and provides a novel view of the incredible variety of spore morphology that has been catalogued by traditional taxonomists for more than 200 years. Rather than representing non-selected variations in micromorphology, the new experiments show that changes in spore architecture have adaptive significance because they control the distance that the spores are shot through air. For this reason, evolutionary modifications to fruiting body architecture, including changes in gill separation and tube diameter in mushrooms, must be tightly linked to alterations in spore morphology.

  11. Blue green alga mediated synthesis of gold nanoparticles and its antibacterial efficacy against Gram positive organisms

    Energy Technology Data Exchange (ETDEWEB)

    Uma Suganya, K.S. [Centre for Ocean Research, Sathyabama University, Chennai 600 119 (India); Govindaraju, K., E-mail: govindtu@gmail.com [Centre for Ocean Research, Sathyabama University, Chennai 600 119 (India); Ganesh Kumar, V.; Stalin Dhas, T.; Karthick, V. [Centre for Ocean Research, Sathyabama University, Chennai 600 119 (India); Singaravelu, G. [Nanoscience Division, Department of Zoology, Thiruvalluvar University, Vellore 632115 (India); Elanchezhiyan, M. [Department of Microbiology, Dr ALM Post Graduate Institute of Basic Medical Sciences, University of Madras, Chennai 600113 (India)

    2015-02-01

    Biofunctionalized gold nanoparticles (AuNPs) play an important role in design and development of nanomedicine. Synthesis of AuNPs from biogenic materials is environmentally benign and possesses high bacterial inhibition and bactericidal properties. In the present study, blue green alga Spirulina platensis protein mediated synthesis of AuNPs and its antibacterial activity against Gram positive bacteria is discussed. AuNPs were characterized using Ultraviolet–visible (UV–vis) spectroscopy, Fluorescence spectroscopy, Fourier Transform-Infrared (FTIR) spectroscopy, Raman spectroscopy, High Resolution-Transmission Electron Microscopy (HR-TEM) and Energy Dispersive X-ray analysis (EDAX). Stable, well defined AuNPs of smaller and uniform shape with an average size of ∼ 5 nm were obtained. The antibacterial efficacy of protein functionalized AuNPs were tested against Gram positive organisms Bacillus subtilis and Staphylococcus aureus. - Highlights: • Size controlled synthesis of gold nanoparticles from blue green alga Spirulina platensis • Stability of gold nanoparticles at different temperatures • Potent antibacterial efficacy against Gram positive organisms.

  12. Inhibition of various gram-positive and gram-negative bacteria growth on selenium nanoparticle coated paper towels.

    Science.gov (United States)

    Wang, Qi; Larese-Casanova, Philip; Webster, Thomas J

    2015-01-01

    There are wide spread bacterial contamination issues on various paper products, such as paper towels hanging in sink splash zones or those used to clean surfaces, filter papers used in water and air purifying systems, and wrappings used in the food industry; such contamination may lead to the potential spread of bacteria and consequent severe health concerns. In this study, selenium nanoparticles were coated on normal paper towel surfaces through a quick precipitation method, introducing antibacterial properties to the paper towels in a healthy way. Their effectiveness at preventing biofilm formation was tested in bacterial assays involving Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus epidermidis. The results showed significant and continuous bacteria inhibition with about a 90% reduction from 24 to 72 hours for gram-positive bacteria including S. aureus and S. epidermidis. The selenium coated paper towels also showed significant inhibition of gram-negative bacteria like P. aeruginosa and E. coli growth at about 57% and 84%, respectively, after 72 hours of treatment. Therefore, this study established a promising selenium-based antibacterial strategy to prevent bacterial growth on paper products, which may lead to the avoidance of bacteria spreading and consequent severe health concerns.

  13. In vitro activity of tigecycline and comparator agents against a global collection of Gram-negative and Gram-positive organisms: tigecycline Evaluation and Surveillance Trial 2004 to 2007.

    Science.gov (United States)

    Garrison, Mark W; Mutters, Reinier; Dowzicky, Michael J

    2009-11-01

    The Tigecycline Evaluation and Surveillance Trial began in 2004 to monitor the in vitro activity of tigecycline and comparator agents against a global collection of Gram-negative and Gram-positive pathogens. Against Gram negatives (n = 63 699), tigecycline MIC(90)'s ranged from 0.25 to 2 mg/L for Escherichia coli, Haemophilus influenzae, Acinetobacter baumannii, Klebsiella oxytoca, Enterobacter cloacae, Klebsiella pneumoniae, and Serratia marcescens (but was > or =32 for Pseudomonas aeruginosa). Against Gram-positive organisms (n = 32 218), tigecycline MIC(90)'s were between 0.06 and 0.25 mg/L for Streptococcus pneumoniae, Enterococcus faecium, Streptococcus agalactiae, Staphylococcus aureus, and Enterococcus faecalis. The in vitro activity of tigecycline was maintained against resistant phenotypes, including multidrug-resistant A. baumannii (9.2% of isolates), extended-spectrum beta-lactamase-producing E. coli (7.0%) and K. pneumoniae (14.0%), beta-lactamase-producing H. influenzae (22.2%), methicillin-resistant S. aureus (44.5%), vancomycin-resistant E. faecium (45.9%) and E. faecalis (2.8%), and penicillin-resistant S. pneumoniae (13.8%). Tigecycline represents a welcome addition to the armamentarium against difficult to treat organisms.

  14. Numerically Stable Evaluation of Moments of Random Gram Matrices With Applications

    KAUST Repository

    Elkhalil, Khalil; Kammoun, Abla; Al-Naffouri, Tareq Y.; Alouini, Mohamed-Slim

    2017-01-01

    This paper focuses on the computation of the positive moments of one-side correlated random Gram matrices. Closed-form expressions for the moments can be obtained easily, but numerical evaluation thereof is prone to numerical stability, especially in high-dimensional settings. This letter provides a numerically stable method that efficiently computes the positive moments in closed-form. The developed expressions are more accurate and can lead to higher accuracy levels when fed to moment based-approaches. As an application, we show how the obtained moments can be used to approximate the marginal distribution of the eigenvalues of random Gram matrices.

  15. Numerically Stable Evaluation of Moments of Random Gram Matrices With Applications

    KAUST Repository

    Elkhalil, Khalil

    2017-07-31

    This paper focuses on the computation of the positive moments of one-side correlated random Gram matrices. Closed-form expressions for the moments can be obtained easily, but numerical evaluation thereof is prone to numerical stability, especially in high-dimensional settings. This letter provides a numerically stable method that efficiently computes the positive moments in closed-form. The developed expressions are more accurate and can lead to higher accuracy levels when fed to moment based-approaches. As an application, we show how the obtained moments can be used to approximate the marginal distribution of the eigenvalues of random Gram matrices.

  16. Gram staining for the treatment of peritonsillar abscess.

    Science.gov (United States)

    Takenaka, Yukinori; Takeda, Kazuya; Yoshii, Tadashi; Hashimoto, Michiko; Inohara, Hidenori

    2012-01-01

    Objective. To examine whether Gram staining can influence the choice of antibiotic for the treatment of peritonsillar abscess. Methods. Between 2005 and 2009, a total of 57 cases of peritonsillar abscess were analyzed with regard to cultured bacteria and Gram staining. Results. Only aerobes were cultured in 16% of cases, and only anaerobes were cultured in 51% of cases. Mixed growth of aerobes and anaerobes was observed in 21% of cases. The cultured bacteria were mainly aerobic Streptococcus, anaerobic Gram-positive cocci, and anaerobic Gram-negative rods. Phagocytosis of bacteria on Gram staining was observed in 9 cases. The bacteria cultured from these cases were aerobic Streptococcus, anaerobic Gram-positive cocci, and anaerobic Gram-negative rods. The sensitivity of Gram staining for the Gram-positive cocci and Gram-negative rods was 90% and 64%, respectively. The specificity of Gram staining for the Gram-positive cocci and Gram-negative rods was 62% and 76%, respectively. Most of the Gram-positive cocci were sensitive to penicillin, but some of anaerobic Gram-negative rods were resistant to penicillin. Conclusion. When Gram staining shows only Gram-positive cocci, penicillin is the treatment of choice. In other cases, antibiotics effective for the penicillin-resistant organisms should be used.

  17. First described case of prosthetic joint infection with Clostridium disporicum.

    Science.gov (United States)

    McBride, Joseph A; Sterkel, Alana K; Rehrauer, William M; Smith, Jeannina A

    2017-12-01

    An orthopedic hardware infection with Clostridium disporicum is described. C. disporicum is a gram positive anaerobic bacillus which can contain two subterminal spores. C. disporicum had not previously been reported in musculoskeletal infections. Gram stains demonstrating gram positive bacilli with two subterminal spores should alert practitioners to the possibility of C. disporicum infection. Published by Elsevier Ltd.

  18. Disruption and analysis of the clpB, clpC, and clpE genes in Lactococcus lactis: ClpE, a new Clp family in gram-positive bacteria

    DEFF Research Database (Denmark)

    Ingmer, Hanne; Vogensen, Finn K.; Hammer, Karin

    1999-01-01

    In the genome of the gram-positive bacterium Lactococcus lactis MG1363, we have identified three genes (clpC, clpE, and clpB) which encode Clp proteins containing two conserved ATP binding domains. The proteins encoded by two of the genes belong to the previously described ClpB and ClpC families....... The clpE gene, however, encodes a member of a new Clp protein family that is characterized by a short N-terminal domain including a putative zinc binding domain (-CX2CX22CX2C-). Expression of the 83-kDa ClpE protein as well as of the two proteins encoded by clpB was strongly induced by heat shock and...... was shown to participate in the degradation of randomly folded proteins in L. lactis, could be necessary for degrading proteins generated by certain types of stress....

  19. Transformation and Stability of Cloned Polysaccharidase Genes in Gram-Positive Bacteria

    OpenAIRE

    EKİNCİ, Mehmet Sait

    2014-01-01

    Polysaccharidase genes from rumen bacteria were transferred to and expressed in ruminal and non-ruminal Gram-positive bacteria. The transformation efficiency and genetic stability of polysaccharidase genes in bacteria from different habitats were investigated. PCR amplification of cloned polysaccharidase genes from Escherichia coli, Lactococcus lactis, Enterococcus faecalis, Streptococcus sanguis and S. bovis strain 26 showed that rearrangement of plasmid and the gene fragment did not occur. ...

  20. Rational approaches to the therapy of nosocomial infections caused by gram-positive microorganisms in cancer p

    Directory of Open Access Journals (Sweden)

    V. V. Aginova

    2017-01-01

    Full Text Available Nosocomial infections caused by gram-positive organisms, including Staphylococcus aureus and enterococci (Enterococcus faecium and Enterococcus faecalis are steadily increasing in almost all clinics around the world. Cancer patients have a higher risk of hospital-acquired infections than non-cancer patients. Cancer patients are immunosuppressed due to increased use of broad-spectrum antibiotics and chemotherapy drugs, radiation therapy, surgery and use of steroids. This paper presents an analysis of resistance of gram-positive bacterial pathogens to antimicrobial agents to determine treatment strategy for cancer patients.

  1. Isolation and identification of a bacterium from marine shrimp digestive tract: A new degrader of starch and protein

    Science.gov (United States)

    Li, Jiqiu; Tan, Beiping; Mai, Kangsen

    2011-09-01

    It is a practical approach to select candidate probiotic bacterial stains on the basis of their special traits. Production of digestive enzyme was used as a trait to select a candidate probiotic bacterial strain in this study. In order to select a bacterium with the ability to degrade both starch and protein, an ideal bacterial strain STE was isolated from marine shrimp ( Litopenaeus vannamei) intestines by using multiple selective media. The selected isolate STE was identified on the basis of its morphological, physiological, and biochemical characteristics as well as molecular analyses. Results of degradation experiments confirmed the ability of the selected isolate to degrade both starch and casein. The isolate STE was aerobic, Gram-negative, rod-shaped, motile and non-spore-forming, and had catalase and oxidase activities but no glucose fermentation activity. Among the tested carbon/nitrogen sources, only Tween40, alanyl-glycine, aspartyl-glycine, and glycyl-l-glutamic acid were utilized by the isolate STE. Results of homology comparison analyses of the 16S rDNA sequences showed that the isolate STE had a high similarity to several Pseudoalteromonas species and, in the phylogenetic tree, grouped with P. ruthenica with maximum bootstrap support (100%). In conclusion, the isolate STE was characterized as a novel strain belonging to the genus Pseudoalteromonas. This study provides a further example of a probiotic bacterial strain with specific characteristics isolated from the host gastrointestinal tract.

  2. [Anthrax due to deliberate infection

    NARCIS (Netherlands)

    Dissel, J.T. van; Kullberg, B.J.; Berg, P.C. van den; Steenbergen, J.E. van

    2001-01-01

    Anthrax is a zoonosis which is particularly prevalent in cattle, goats and sheep and is caused by Bacillus anthracis, a Gram-positive spore forming aerobic microorganism. The endospores can survive outside of the body for many decades. The natural form of anthrax has a cutaneous, pulmonary and

  3. Differential staining of bacteria: gram stain.

    Science.gov (United States)

    Moyes, Rita B; Reynolds, Jackie; Breakwell, Donald P

    2009-11-01

    In 1884, Hans Christian Gram, a Danish doctor, developed a differential staining technique that is still the cornerstone of bacterial identification and taxonomic division. This multistep, sequential staining protocol separates bacteria into four groups based on cell morphology and cell wall structure: Gram-positive cocci, Gram-negative cocci, Gram-positive rods, and Gram-negative rods. The Gram stain is useful for assessing bacterial contamination of tissue culture samples or for examining the Gram stain status and morphological features of bacteria isolated from mixed or isolated bacterial cultures. (c) 2009 by John Wiley & Sons, Inc.

  4. Antibacterial activity of sphingoid bases and fatty acids against Gram-positive and Gram-negative bacteria.

    Science.gov (United States)

    Fischer, Carol L; Drake, David R; Dawson, Deborah V; Blanchette, Derek R; Brogden, Kim A; Wertz, Philip W

    2012-03-01

    There is growing evidence that the role of lipids in innate immunity is more important than previously realized. How lipids interact with bacteria to achieve a level of protection, however, is still poorly understood. To begin to address the mechanisms of antibacterial activity, we determined MICs and minimum bactericidal concentrations (MBCs) of lipids common to the skin and oral cavity--the sphingoid bases D-sphingosine, phytosphingosine, and dihydrosphingosine and the fatty acids sapienic acid and lauric acid--against four Gram-negative bacteria and seven Gram-positive bacteria. Exact Kruskal-Wallis tests of these values showed differences among lipid treatments (P 500 μg/ml). Sapienic acid (MBC range, 31.3 to 375.0 μg/ml) was active against Streptococcus sanguinis, Streptococcus mitis, and Fusobacterium nucleatum but not active against Escherichia coli, Staphylococcus aureus, S. marcescens, P. aeruginosa, Corynebacterium bovis, Corynebacterium striatum, and Corynebacterium jeikeium (MBC > 500 μg/ml). Lauric acid (MBC range, 6.8 to 375.0 μg/ml) was active against all bacteria except E. coli, S. marcescens, and P. aeruginosa (MBC > 500 μg/ml). Complete killing was achieved as early as 0.5 h for some lipids but took as long as 24 h for others. Hence, sphingoid bases and fatty acids have different antibacterial activities and may have potential for prophylactic or therapeutic intervention in infection.

  5. Food sensing: selection and characterization of DNA aptamers to Alicyclobacillus spores for trapping and detection from orange juice.

    Science.gov (United States)

    Hünniger, Tim; Fischer, Christin; Wessels, Hauke; Hoffmann, Antonia; Paschke-Kratzin, Angelika; Haase, Ilka; Fischer, Markus

    2015-03-04

    The quality of the beverage industry's products has to be constantly monitored to fulfill consumers' high expectations. The thermo-acidophilic Gram-positive Alicyclobacillus spp. are not pathogenic, but their heat-resistant endospores can survive juice-processing conditions and have become a major economic concern for the fruit juice industry. Current detection methods rely on cultivation, isolation, and organism identification, which can take up to a week, resulting in economic loss. This work presents the selection and identification of DNA aptamers targeting Alicyclobacillus spores by spore-SELEX (systematic evolution of ligands by exponential enrichment) in orange-juice-simulating buffer. The selection process was verified by various techniques, including flow cytometric binding assays, radioactive binding assays, and agarose gel electrophoresis. The subsequent aptamer characterization included the determination of dissociations constants and selectivity by different techniques, such as surface plasmon resonance spectroscopy and fluorescence microscopy. In summary, 10 different aptamers with an affinity to Alicyclobacillus spp. have been developed, analyzed, and characterized in terms of affinity and specificity.

  6. A synbio approach for selection of highly expressed gene variants in Gram-positive bacteria.

    Science.gov (United States)

    Ferro, Roberto; Rennig, Maja; Hernández-Rollán, Cristina; Daley, Daniel O; Nørholm, Morten H H

    2018-03-08

    The market for recombinant proteins is on the rise, and Gram-positive strains are widely exploited for this purpose. Bacillus subtilis is a profitable host for protein production thanks to its ability to secrete large amounts of proteins, and Lactococcus lactis is an attractive production organism with a long history in food fermentation. We have developed a synbio approach for increasing gene expression in two Gram-positive bacteria. First of all, the gene of interest was coupled to an antibiotic resistance gene to create a growth-based selection system. We then randomised the translation initiation region (TIR) preceding the gene of interest and selected clones that produced high protein titres, as judged by their ability to survive on high concentrations of antibiotic. Using this approach, we were able to significantly increase production of two industrially relevant proteins; sialidase in B. subtilis and tyrosine ammonia lyase in L. lactis. Gram-positive bacteria are widely used to produce industrial enzymes. High titres are necessary to make the production economically feasible. The synbio approach presented here is a simple and inexpensive way to increase protein titres, which can be carried out in any laboratory within a few days. It could also be implemented as a tool for applications beyond TIR libraries, such as screening of synthetic, homologous or domain-shuffled genes.

  7. Peptidoglycan Recycling in Gram-Positive Bacteria Is Crucial for Survival in Stationary Phase

    Science.gov (United States)

    Borisova, Marina; Gaupp, Rosmarie; Duckworth, Amanda; Schneider, Alexander; Dalügge, Désirée; Mühleck, Maraike; Deubel, Denise; Unsleber, Sandra; Yu, Wenqi; Muth, Günther; Bischoff, Markus; Götz, Friedrich

    2016-01-01

    ABSTRACT Peptidoglycan recycling is a metabolic process by which Gram-negative bacteria reutilize up to half of their cell wall within one generation during vegetative growth. Whether peptidoglycan recycling also occurs in Gram-positive bacteria has so far remained unclear. We show here that three Gram-positive model organisms, Staphylococcus aureus, Bacillus subtilis, and Streptomyces coelicolor, all recycle the sugar N-acetylmuramic acid (MurNAc) of their peptidoglycan during growth in rich medium. They possess MurNAc-6-phosphate (MurNAc-6P) etherase (MurQ in E. coli) enzymes, which are responsible for the intracellular conversion of MurNAc-6P to N-acetylglucosamine-6-phosphate and d-lactate. By applying mass spectrometry, we observed accumulation of MurNAc-6P in MurNAc-6P etherase deletion mutants but not in either the isogenic parental strains or complemented strains, suggesting that MurQ orthologs are required for the recycling of cell wall-derived MurNAc in these bacteria. Quantification of MurNAc-6P in ΔmurQ cells of S. aureus and B. subtilis revealed small amounts during exponential growth phase (0.19 nmol and 0.03 nmol, respectively, per ml of cells at an optical density at 600 nm [OD600] of 1) but large amounts during transition (0.56 nmol and 0.52 nmol) and stationary (0.53 nmol and 1.36 nmol) phases. The addition of MurNAc to ΔmurQ cultures greatly increased the levels of intracellular MurNAc-6P in all growth phases. The ΔmurQ mutants of S. aureus and B. subtilis showed no growth deficiency in rich medium compared to the growth of the respective parental strains, but intriguingly, they had a severe survival disadvantage in late stationary phase. Thus, although peptidoglycan recycling is apparently not essential for the growth of Gram-positive bacteria, it provides a benefit for long-term survival. PMID:27729505

  8. Expression and characterization of a novel spore wall protein from ...

    African Journals Online (AJOL)

    Microsporidia are obligate intracellular, eukaryotic, spore-forming parasites. The environmentally resistant spores, which harbor a rigid cell wall, are critical for their survival outside their host cells and host-to-host transmission. The spore wall comprises two major layers: the exospore and the endospore. In Nosema ...

  9. Sterilization of beehive material with a double inductively coupled low pressure plasma

    International Nuclear Information System (INIS)

    Priehn, M; Leichert, L I; Denis, B; Awakowicz, P; Aumeier, P; Kirchner, W H

    2016-01-01

    American Foulbrood is a severe, notifiable disease of the honey bee. It is caused by infection of bee larvae with spores of the gram-positive bacterium Paenibacillus larvae . Spores of this organism are found in high numbers in an infected hive and are highly resistant to physical and chemical inactivation methods. The procedures to rehabilitate affected apiaries often result in the destruction of beehive material. In this study we assess the suitability of a double inductively coupled low pressure plasma as a non-destructive, yet effective alternative inactivation method for bacterial spores of the model organism Bacillus subtilis on beehive material. Plasma treatment was able to effectively remove spores from wax, which, under protocols currently established in veterinary practice, normally is destroyed by ignition or autoclaved for sterilization. Spores were removed from wooden surfaces with efficacies significantly higher than methods currently used in veterinary practice, such as scorching by flame treatment. In addition, we were able to non-destructively remove spores from the highly delicate honeycomb wax structures, potentially making treatment of beehive material with double inductively coupled low pressure plasma part of a fast and reliable method to rehabilitate infected bee colonies with the potential to re-use honeycombs. (paper)

  10. Anoxybacillus kamchatkensis subsp. asaccharedens subsp. nov., a thermophilic bacterium isolated from a hot spring in Batman.

    Science.gov (United States)

    Gul-Guven, Reyhan; Guven, Kemal; Poli, Annarita; Nicolaus, Barbara

    2008-12-01

    A new thermophilic spore-forming strain KG8(T) was isolated from the mud of Taslidere hot spring in Batman. Strain KG8(T) was aerobe, Gram-positive, rod-shaped, motile, occurring in pairs or filamentous. Growth was observed from 35-65 degrees C (optimum 55 degrees C) and at pH 5.5-9.5 (optimum pH 7.5). It was capable of utilizing starch, growth was observed until 3% NaCl (w/v) and it was positive for nitrate reduction. On the basis of 16S rRNA gene sequence similarity, strain KG8(T) was shown to be related most closely to Anoxybacillus species. Chemotaxonomic data (major isoprenoid quinone-menaquinone-7; major fatty acid-iso-C15:0 and iso-C17:0) supported the affiliation of strain KG8(T) to the genus Anoxybacillus. The results of DNA-DNA hybridization, physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain KG8(T). Based on these results we propose assigning a novel subspecies of Anoxybacillus kamchatkensis, to be named Anoxybacillus kamchatkensis subsp. asaccharedens subsp. nov. with the type strain KG8(T) (DSM 18475(T)=CIP 109280(T)).

  11. Investigation of spore forming bacterial flooding for enhanced oil recovery in a North Sea chalk Reservoir

    DEFF Research Database (Denmark)

    Halim, Amalia Yunita; Nielsen, Sidsel Marie; Eliasson Lantz, Anna

    2015-01-01

    Little has been done to study microbial enhanced oil recovery (MEOR) in chalk reservoirs. The present study focuses on core flooding experiments designed to see microbial plugging and its effect on oil recovery. A pressure tapped core holder was used for this purpose. A spore forming bacteria...... Bacillus licheniformis 421 was used as it was shown to be a good candidate in a previous study. Bacterial spore can penetrate deeper into the chalk rock, squeezing through the pore throats. Our results showed that injection of B. licheniformis 421 as a tertiary oil recovery method, in the residual oil...... saturation state, was able to produce additionally 1.0-2.3% original oil in place (OOIP) in homogeneous cores and 6.9-8.8% OOIP in heterogeneous cores. In addition, the pressure gradient was much higher in the heterogeneous cores, which confirms that bacterial selective plugging plays an important role...

  12. Flavins mediate extracellular electron transfer in Gram-positive Bacillus megaterium strain LLD-1

    DEFF Research Database (Denmark)

    You, Le-Xing; Liu, Li-Dan; Xiao, Yong

    2018-01-01

    The extracellular electron transfer (EET) mechanism of an isolated Gram-positive Bacillus megaterium strain (LLD-1), identified by 16S rRNA gene sequencing and physiological analysis, was investigated in the present study. The electrochemical activity of strain LLD-1 was confirmed by electrochemi...

  13. Plutonium uptake by a soil fungus and transport to its spores

    International Nuclear Information System (INIS)

    Beckert, W.F.; Au, F.H.F.

    1976-01-01

    Three concentrations of plutonium-238 nitrate, citrate and dioxide were each added to separate plates of malt agar buffered to pH 2.5 and 5.5 to determine the uptake of plutonium from these chemical forms and concentrations by a common soil fungus, Aspergillus niger. After inoculation and incubation, the aerial spores of Aspergillus niger were collected using a technique that excluded the possibility of cross-contamination of the spores by the culture media or by mycelial fragments. 238 Pu was taken up from all three chemical forms and transported to the aerial spores of Aspergillus niger at each concentration and at both pH levels. The specific activities of the spores grown at pH 5.5 were generally at least twice those of the spores grown at pH 2.5. The uptake of plutonium from the dioxide form was about one-third of that from the nitrate and citrate forms at both pH levels. The term 'transport factor' is used as a means to compare the transport of plutonium from the media to the fungal spores; the concentration-independent transport factor is defined as the specific activity of the spores divided by the specific activity of the dry culture medium. Though the transport factors were less than 1, which indicates discrimination against the transport of 238 Pu from the culture media to the spores, these findings suggest that this common soil fungus may be solubilizing soil-deposited plutonium and rendering it more biologically available for higher plants and animals. (author)

  14. The Effect of Charge at the Surface of Silver Nanoparticles on Antimicrobial Activity against Gram-Positive and Gram-Negative Bacteria: A Preliminary Study

    International Nuclear Information System (INIS)

    Abbaszadegan, A.; Ghahramani, Y.; Nabavizadeh, M.; Gholami, A.; Hemmateenejad, I.; Dorostkar, S.; Sharghi, H.

    2014-01-01

    The bactericidal efficiency of various positively and negatively charged silver nanoparticles has been extensively evaluated in literature, but there is no report on efficacy of neutrally charged silver nanoparticles. The goal of this study is to evaluate the role of electrical charge at the surface of silver nanoparticles on antibacterial activity against a panel of microorganisms. Three different silver nanoparticles were synthesized by different methods, providing three different electrical surface charges (positive, neutral, and negative). The antibacterial activity of these nanoparticles was tested against gram-positive (i.e., Staphylococcus aureus, Streptococcus mutans, and Streptococcus pyogenes) and gram-negative (i.e., Escherichia coli and Proteus vulgaris) bacteria. Well diffusion and micro-dilution tests were used to evaluate the bactericidal activity of the nanoparticles. According to the obtained results, the positively-charged silver nanoparticles showed the highest bactericidal activity against all microorganisms tested. The negatively charged silver nanoparticles had the least and the neutral nanoparticles had intermediate antibacterial activity. The most resistant bacteria were Proteus vulgaris. We found that the surface charge of the silver nanoparticles was a significant factor affecting bactericidal activity on these surfaces. Although the positively charged nanoparticles showed the highest level of effectiveness against the organisms tested, the neutrally charged particles were also potent against most bacterial species.

  15. Gram-positive bacteria as an antigen topically applied into gingival sulcus of immunized rat accelerates periodontal destruction.

    Science.gov (United States)

    Nagano, F; Kaneko, T; Yoshinaga, Y; Ukai, T; Kuramoto, A; Nakatsu, S; Oshino, K; Ichimura, I; Hara, Y

    2013-08-01

    Periodontitis is generally accepted to relate to gram-negative bacteria, and the host defense system influences its onset and progression. However, little is known about the relation between gram-positive bacteria and periodontitis. In this study, we topically applied gram-positive and gram-negative bacterial suspensions to the gingival sulcus in rats after immunization, and then histopathologically examined their influence on periodontal destruction. Rats previously immunized with heat-treated and sonicated Staphylococcus aureus or Aggregatibacter actinomycetemcomitans were used as immunized groups. The non-immunized group received only sterile phosphate-buffered saline. In each animal, S. aureus or A. actinomycetemcomitans suspension was applied topically to the palatal gingival sulcus of first molars every 24 h for 10 d. Blood samples were collected and the serum level of anti-S. aureus or anti-A. actinomycetemcomitans immunoglobulin G (IgG) antibodies was determined by enzyme-linked immunosorbent assay. The first molar regions were resected and observed histopathologically. Osteoclasts were stained with tartrate-resistant acid phosphatase (TRAP). The formation of immune complexes was confirmed by immunohistological staining of C1qB. Serum levels of anti-S. aureus and anti-A. actinomycetemcomitans IgG antibodies in the immunized groups were significantly higher than those in the non-immunized groups were. The loss of attachment, increase in apical migration of the junctional epithelium, and decreases in alveolar bone level and number of TRAP-positive multinuclear cells in each immunized group were significantly greater than in each non-immunized group. The presence of C1qB was observed in the junctional epithelium and adjacent connective tissue in the immunized groups. Heat-treated and sonicated S. aureus and A. actinomycetemcomitans induced attachment loss in rats immunized with their suspensions. Our results suggest that not only gram-negative but also gram-positive

  16. [Microbial resistance to formaldehyde. I. Comparative quantitative studies in some selected species of vegetative bacteria, bacterial spores, fungi, bacteriophages and viruses].

    Science.gov (United States)

    Spicher, G; Peters, J

    1976-12-01

    The resistence of different microorganisms to formaldehyde was determined. As test objects served gram-negative and gram-positive vegetative germs (Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella paratyphi-B, Staphylococcus aureus, Streptococcus faecalis), bacterial spores (Bacillus cereus, Bacillus pumilus, Bacillus stearothermophilus, Bacillus subtilis), fungi (Aspergillus niger, Candida albicans), bacteriophages (Escherichia coli phages, T1, T2, T3), and viruses (adenovirus, poliomyelitis virus, vaccinia virus). For the studies, suspensions of germs were exposed at identical temperature (20 degrees C) and pH (7.0). The microbicidal effect of formaldehyde was measured by the decrease of the proportion of germs capable of multiplication in the suspension (lg (N/N0); where: N0 equals initial number of germs capable of multiplication; N equals number of germs capable of multiplication after exposure to formaldehyde). For all germs the dependence of the microbicidal effect on the concentration of formaldehyde was determined. In all experiments, the duration of exposure was two hours. Pseudomonas aeruginosa, Klebsiella pneumoniae, and Salmonella paratyphi-B were found to be more susceptible than Staphylococcus aureus (vf. Fig. 1 A). The strains of Pseudomonas aeruginosa used were widely varying as to their susceptibility. To obtain equal microbicidal effects, concentrations of formaldehyde almost three times as high had to be used for the most resistant strain than were necessary for the most susceptible strain of Pseudomonas aeruginosa. All strains of Klebsiella pneumoniae examined were found to have an identical resistence to formaldehyde. Streptococcus faecalis was even more resistant to formaldehyde than Staphylococcus aureus. In the case of Streptococcus faecalis, a concentration of formaldehyde about three times as high had to be used to obtain microbicidal effects of identical magnitude. For the killing of Candida albicans cells concentrations of

  17. Contribution of fungal spores to particulate matter in a tropical rainforest

    International Nuclear Information System (INIS)

    Zhang Ting; Chan Chuenyu; Zhang Yinan; Zhang Zhisheng; Lin Mang; Sang Xuefang; Engling, Guenter; Li, Y D; Li, Yok-Sheung

    2010-01-01

    The polyols arabitol and mannitol, recently proposed as source tracers for fungal spores, were used in this study to estimate fungal contributions to atmospheric aerosol. Airborne particulate matter (PM 2.5 and PM 10 ) was collected at Jianfengling Mountain, a tropical rainforest on Hainan Island situated off the south China coast, during spring and analyzed for arabitol and mannitol by high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD). The average concentrations of arabitol and mannitol exhibited high values with averages of 7.0 and 16.0 ng m -3 respectively in PM 2.5 and 44.0 and 71.0 ng m -3 in PM 10 . The two tracers correlated well with each other, especially in the coarse mode aerosol (PM 2.5-10 ), indicating they were mainly associated with coarse aerosol particles and had common sources. Arabitol and mannitol in PM 10 showed significant positive correlations with relative humidity, as well as positive correlations with average temperature, suggesting a wet emissions mechanism of biogenic aerosol in the form of fungal spores. We made estimations of the contribution of fungal spores to ambient PM mass and to organic carbon, based on the observed ambient concentrations of these two tracers. The relative contributions of fungal spores to the PM 10 mass were estimated to range from 1.6 to 18.2%, with a rather high mean value of 7.9%, and the contribution of fungal spores to organic carbon in PM 10 ranged from 4.64 to 26.1%, with a mean value of 12.1%, implying that biological processes are important sources of atmospheric aerosol.

  18. Genome sequence of the pattern forming Paenibacillus vortex bacterium reveals potential for thriving in complex environments

    NARCIS (Netherlands)

    Sirota-Madi, A.; Olender, T.; Helman, Y.; Ingham, C.; Brainis, I.; Roth, D.; Hagi, E.; Brodsky, L.; Leshkowitz, D.; Galatenko, V.; Nikolaev, V.; Mugasimangalam, R.C.; Bransburg-Zabary, S.; Gutnick, D.L.; Lancet, D.; Ben-Jacob, E.

    2010-01-01

    Background: The pattern-forming bacterium Paenibacillus vortex is notable for its advanced social behavior, which is reflected in development of colonies with highly intricate architectures. Prior to this study, only two other Paenibacillus species (Paenibacillus sp. JDR-2 and Paenibacillus larvae)

  19. Adsorption of β-galactosidase of Alicyclobacillus acidocaldarius on wild type and mutants spores of Bacillus subtilis

    Directory of Open Access Journals (Sweden)

    Sirec Teja

    2012-08-01

    Full Text Available Abstract Background The Bacillus subtilis spore has long been used as a surface display system with potential applications in a variety of fields ranging from mucosal vaccine delivery, bioremediation and biocatalyst development. More recently, a non-recombinant approach of spore display has been proposed and heterologous proteins adsorbed on the spore surface. We used the well-characterized β-galactosidase from the thermoacidophilic bacterium Alicyclobacillus acidocaldarius as a model to study enzyme adsorption, to analyze whether and how spore-adsorption affects the properties of the enzyme and to improve the efficiency of the process. Results We report that purified β-galactosidase molecules were adsorbed to purified spores of a wild type strain of B. subtilis retaining ca. 50% of their enzymatic activity. Optimal pH and temperature of the enzyme were not altered by the presence of the spore, that protected the adsorbed β-galactosidase from exposure to acidic pH conditions. A collection of mutant strains of B. subtilis lacking a single or several spore coat proteins was compared to the isogenic parental strain for the adsorption efficiency. Mutants with an altered outermost spore layer (crust were able to adsorb 60-80% of the enzyme, while mutants with a severely altered or totally lacking outer coat adsorbed 100% of the β-galactosidase molecules present in the adsorption reaction. Conclusion Our results indicate that the spore surface structures, the crust and the outer coat layer, have an negative effect on the adhesion of the β-galactosidase. Electrostatic forces, previously suggested as main determinants of spore adsorption, do not seem to play an essential role in the spore-β-galactosidase interaction. The analysis of mutants with altered spore surface has shown that the process of spore adsorption can be improved and has suggested that such improvement has to be based on a better understanding of the spore surface structure

  20. Structural modifications of bacterial lipopolysaccharide that facilitate Gram-negative bacteria evasion of host innate immunity

    Directory of Open Access Journals (Sweden)

    Motohiro eMatsuura

    2013-05-01

    Full Text Available Bacterial lipopolysaccharide (LPS, a cell wall component characteristic of Gram-negative bacteria, is a representative pathogen-associated molecular pattern that allows mammalian cells to recognize bacterial invasion and trigger innate immune responses. The polysaccharide moiety of LPS primary plays protective roles for bacteria such as prevention from complement attacks or camouflage with common host carbohydrate residues. The lipid moiety, termed lipid A, is recognized by the Toll-like receptor 4 (TLR4/MD-2 complex, which transduces signals for activation of host innate immunity. The basic structure of lipid A is a glucosamine disaccharide substituted by phosphate groups and acyl groups. Lipid A with 6 acyl groups (hexa-acylated form has been indicated to be a strong stimulator of the TLR4/MD-2 complex. This type of lipid A is conserved among a wide variety of Gram-negative bacteria, and those bacteria are easily recognized by host cells for activation of defensive innate immune responses. Modifications of the lipid A structure to less-acylated forms have been observed in some bacterial species, and those forms are poor stimulators of the TLR4/MD-2 complex. Such modifications are thought to facilitate bacterial evasion of host innate immunity, thereby enhancing pathogenicity. This hypothesis is supported by studies of Yersinia pestis LPS, which contains hexa-acylated lipid A when the bacterium grows at 27ºC (the temperature of the vector flea, and shifts to contain less-acylated forms when grown at the human body temperature of 37ºC. This alteration of lipid A forms following transmission of Y. pestis from fleas to humans contributes predominantly to the virulence of this bacterium over other virulence factors. A similar role for less-acylated lipid A forms has been indicated in some other bacterial species, such as Francisella tularensis, Helicobacter pylori, and Porphyromonas gingivalis, and further studies to explore this concept are

  1. Life in Darwin's dust: intercontinental transport and survival of microbes in the nineteenth century.

    Science.gov (United States)

    Gorbushina, Anna A; Kort, Renate; Schulte, Anette; Lazarus, David; Schnetger, Bernhard; Brumsack, Hans-Jürgen; Broughton, William J; Favet, Jocelyne

    2007-12-01

    Charles Darwin, like others before him, collected aeolian dust over the Atlantic Ocean and sent it to Christian Gottfried Ehrenberg in Berlin. Ehrenberg's collection is now housed in the Museum of Natural History and contains specimens that were gathered at the onset of the Industrial Revolution. Geochemical analyses of this resource indicated that dust collected over the Atlantic in 1838 originated from the Western Sahara, while molecular-microbiological methods demonstrated the presence of many viable microbes. Older samples sent to Ehrenberg from Barbados almost two centuries ago also contained numbers of cultivable bacteria and fungi. Many diverse ascomycetes, and eubacteria were found. Scanning electron microscopy and cultivation suggested that Bacillus megaterium, a common soil bacterium, was attached to historic sand grains, and it was inoculated onto dry sand along with a non-spore-forming control, the Gram-negative soil bacterium Rhizobium sp. NGR234. On sand B. megaterium quickly developed spores, which survived for extended periods and even though the numbers of NGR234 steadily declined, they were still considerable after months of incubation. Thus, microbes that adhere to Saharan dust can live for centuries and easily survive transport across the Atlantic.

  2. Isolation and characterization of a radiation resistant thermophilic bacterium from radon hot spring

    International Nuclear Information System (INIS)

    Liang Xinle; Yang Long; Zhang Hong; Zhang Lei

    2011-01-01

    A radiation resistant and thermophilic bacterium strain R4-33 was isolated from radon hot spring water samples, pretreated with 60 Co γ-rays and UV irradiation. Tests on morphological, physiological and biochemical characters, fatty acid compositions, (G + C) mol% contents, and 16S rDNA sequencing were conducted. The results showed that strain R4-33 was of rod-shape, Gram-negative, atrichous, and endospore-forming. The optimum growth temperature and pH were 60 ℃ and 7.5, respectively. The strain utilized glucose, maltose and trehalose as carbon sources, and hydrolyzed casein and starch. Its catalase positive. The strain was sensitive to penicillin, neomycin, erythromycin, vancomycin, streptomycin, gentamycin, amikacin and ampicillin. The major cellular fatty acids were C 14:1 (48.8%) and C 15:1 (15.2%). The (G + C) mol% content of DNA was 58.2%. Phylogenetic tree based on 16S rDNA sequence showed R4-33 shared highly similarity to those of species in genus Anoxybacillus, especially to that of Anoxybacillus gonensis (99.5%). Based on the above, the strain R4-33 was proposed to the evolution branch of Anoxybacillus and designated as Anoxybacillu sp. R4-33. The UV and γ-radiation tests showed that the strain R4-33 had an ability of resistance to UV of 396 J/m 2 and 60 Co γ-rays irradiation of 14.0 kGy, indicating that the strain was a radiation resistant and thermophilic bacterium. (authors)

  3. Endocarditis associated with cardiac catheterization due to a Gram-positive coccus designated Micrococcus mucilaginosus incertae sedis.

    Science.gov (United States)

    Rubin, S J; Lyons, R W; Murcia, A J

    1978-01-01

    A gram-positive coccus, presently named Micrococcus mucilaginosus incertae sedis, was isolated from 14 blood cultures from a patient with endocarditis. The first positive blood culture was drawn 5 days after the patient underwent cardiac catheterization. PMID:670378

  4. Vermin on pig farms are vectors for Clostridium difficile PCR ribotypes 078 and 045

    NARCIS (Netherlands)

    Burt, S.A.; Siemeling, L.; Kuijper, E.J.; Lipman, L.J.A.

    2012-01-01

    Clostridium difficile is a gram positive, spore forming, toxin producing, anaerobic bacteria and an opportunistic pathogen for Man and many animal species, causing diarrhea in young piglets. Piglets probably become colonized from the environment. To investigate the possible spread and transmission

  5. Loktanella spp. Gb03 as an algicidal bacterium, isolated from the culture of Dinoflagellate Gambierdiscus belizeanus.

    Science.gov (United States)

    Bloh, Anmar Hameed; Usup, Gires; Ahmad, Asmat

    2016-02-01

    Bacteria associated with harmful algal blooms can play a crucial role in regulating algal blooms in the environment. This study aimed at isolating and identifying algicidal bacteria in Dinoflagellate culture and to determine the optimum growth requirement of the algicidal bacteria, Loktanella sp. Gb-03. The Dinoflagellate culture used in this study was supplied by Professor Gires Usup's Laboratory, School of Environmental and Natural Resources Sciences, Faculty of Science and Technology, University Kebangsaan Malaysia, Malaysia. The culture was used for the isolation of Loktanella sp., using biochemical tests, API 20 ONE kits. The fatty acid content of the isolates and the algicidal activity were further evaluated, and the phenotype was determined through the phylogenetic tree. Gram-negative, non-motile, non-spore-forming, short rod-shaped, aerobic bacteria (Gb01, Gb02, Gb03, Gb04, Gb05, and Gb06) were isolated from the Dinoflagellate culture. The colonies were pink in color, convex with a smooth surface and entire edge. The optimum growth temperature for the Loktanella sp. Gb03 isolate was determined to be 30°C, in 1% of NaCl and pH7. Phylogenetic analysis based on 16S rRNA gene sequences showed that the bacterium belonged to the genus Loktanella of the class Alphaproteobacteria and formed a tight cluster with the type strain of Loktanella pyoseonensis (97.0% sequence similarity). On the basis of phenotypic, phylogenetic data and genetic distinctiveness, strain Gb-03, were placed in the genus Loktanella as the type strain of species. Moreover, it has algicidal activity against seven toxic Dinoflagellate. The algicidal property of the isolated Loktanella is vital, especially where biological control is needed to mitigate algal bloom or targeted Dinoflagellates.

  6. A synbio approach for selection of highly expressed gene variants in Gram-positive bacteria

    DEFF Research Database (Denmark)

    Ferro, Roberto; Rennig, Maja; Hernández Rollán, Cristina

    2018-01-01

    with a long history in food fermentation. We have developed a synbio approach for increasing gene expression in two Gram-positive bacteria. First of all, the gene of interest was coupled to an antibiotic resistance gene to create a growth-based selection system. We then randomised the translation initiation...... region (TIR) preceding the gene of interest and selected clones that produced high protein titres, as judged by their ability to survive on high concentrations of antibiotic. Using this approach, we were able to significantly increase production of two industrially relevant proteins; sialidase in B....... subtilis and tyrosine ammonia lyase in L. lactis. Gram-positive bacteria are widely used to produce industrial enzymes. High titres are necessary to make the production economically feasible. The synbio approach presented here is a simple and inexpensive way to increase protein titres, which can be carried...

  7. Microbial enhanced heavy oil recovery by the aid of inhabitant spore-forming bacteria: an insight review.

    Science.gov (United States)

    Shibulal, Biji; Al-Bahry, Saif N; Al-Wahaibi, Yahya M; Elshafie, Abdulkader E; Al-Bemani, Ali S; Joshi, Sanket J

    2014-01-01

    Crude oil is the major source of energy worldwide being exploited as a source of economy, including Oman. As the price of crude oil increases and crude oil reserves collapse, exploitation of oil resources in mature reservoirs is essential for meeting future energy demands. As conventional recovery methods currently used have become less efficient for the needs, there is a continuous demand of developing a new technology which helps in the upgradation of heavy crude oil. Microbial enhanced oil recovery (MEOR) is an important tertiary oil recovery method which is cost-effective and eco-friendly technology to drive the residual oil trapped in the reservoirs. The potential of microorganisms to degrade heavy crude oil to reduce viscosity is considered to be very effective in MEOR. Earlier studies of MEOR (1950s) were based on three broad areas: injection, dispersion, and propagation of microorganisms in petroleum reservoirs; selective degradation of oil components to improve flow characteristics; and production of metabolites by microorganisms and their effects. Since thermophilic spore-forming bacteria can thrive in very extreme conditions in oil reservoirs, they are the most suitable organisms for the purpose. This paper contains the review of work done with thermophilic spore-forming bacteria by different researchers.

  8. Microbial Enhanced Heavy Oil Recovery by the Aid of Inhabitant Spore-Forming Bacteria: An Insight Review

    Directory of Open Access Journals (Sweden)

    Biji Shibulal

    2014-01-01

    Full Text Available Crude oil is the major source of energy worldwide being exploited as a source of economy, including Oman. As the price of crude oil increases and crude oil reserves collapse, exploitation of oil resources in mature reservoirs is essential for meeting future energy demands. As conventional recovery methods currently used have become less efficient for the needs, there is a continuous demand of developing a new technology which helps in the upgradation of heavy crude oil. Microbial enhanced oil recovery (MEOR is an important tertiary oil recovery method which is cost-effective and eco-friendly technology to drive the residual oil trapped in the reservoirs. The potential of microorganisms to degrade heavy crude oil to reduce viscosity is considered to be very effective in MEOR. Earlier studies of MEOR (1950s were based on three broad areas: injection, dispersion, and propagation of microorganisms in petroleum reservoirs; selective degradation of oil components to improve flow characteristics; and production of metabolites by microorganisms and their effects. Since thermophilic spore-forming bacteria can thrive in very extreme conditions in oil reservoirs, they are the most suitable organisms for the purpose. This paper contains the review of work done with thermophilic spore-forming bacteria by different researchers.

  9. Stable transformation of the gram-positive phytopathogenic bacterium Clavibacter michiganensis subsp. sepedonicus with several cloning vectors.

    Science.gov (United States)

    Laine, M J; Nakhei, H; Dreier, J; Lehtilä, K; Meletzus, D; Eichenlaub, R; Metzler, M C

    1996-05-01

    In this paper we describe transformation of Clavibacter michiganensis subsp. sepedonicus, the potato ring rot bacterium, with plasmid vectors. Three of the plasmids used, pDM100, pDM302, and pDM306, contain the origin of replication from pCM1, a native plasmid of C. michiganensis subsp. michiganensis. We constructed two new cloning vectors, pHN205 and pHN216, by using the origin of replication of pCM2, another native plasmid of C. michiganensis subsp. michiganensis. Plasmids pDM302, pHN205, and pHN216 were stably maintained without antibiotic selection in various strains of C. michiganensis subsp. sepedonicus. We observed that for a single plasmid, different strains of C. michiganensis subsp. sepedonicus showed significantly different transformation efficiencies. We also found unexplained strain-to-strain differences in stability with various plasmid constructions containing different arrangements of antibiotic resistance genes and origins of replication. We examined the effect of a number of factors on transformation efficiency. The best transformation efficiencies were obtained when C. michiganensis subsp. sepedonicus cells were grown on DM agar plates, harvested during the early exponential growth phase, and used fresh (without freezing) for electroporation. The maximal transformation efficiency obtained was 4.6 x 10(4) CFU/microgram of pHN216 plasmid DNA. To demonstrate the utility of this transformation system, we cloned a beta-1,4-endoglucanase-encoding gene from C. michiganensis subsp. sepedonicus into pHN216. When this construction, pHN216:C8, was electroporated into competent cells of a cellulase-deficient mutant, it restored cellulase production to almost wild-type levels.

  10. Zymomonas mobilis: a bacterium for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Baratti, J.C.; Bu' Lock, J.D.

    1986-01-01

    Zymomonas mobilis is a facultative anaerobic gram negative bacterium first isolated in tropical countries from alcoholic beverages like the African palm wine, the Mexican pulque and also as a contaminant of cider (cider sickness) or beer in the European countries. It is one of the few facultative anaerobic bacteria degrading glucose by the Entner-Doudoroff pathway usually found in strictly aerobic microorganisms. Some work was devoted to this bacterium in the 50s and 60s and was reviewed by Swings and De Ley in their classical paper published in 1977. During the 70s there was very little work on the bacterium until 1979 and the first report by the Australian group of P.L. Rogers on the great potentialities of Z. mobilis for ethanol production. At that time the petroleum crisis had led the developed countries to search for alternative fuel from renewable resources. The Australian group clearly demonstrated the advantages of the bacterium compared to the yeasts traditionally used for the alcoholic fermentation. As a result, there was a considerable burst in the Zymomonas literature which started from nearly zero in the late 70s to attain 70 papers published in the field in 1984. In this article, papers published from 1982 to 1986 are reviewed.

  11. The comparison of pyrosequencing molecular Gram stain, culture, and conventional Gram stain for diagnosing orthopaedic infections.

    Science.gov (United States)

    Kobayashi, Naomi; Bauer, Thomas W; Tuohy, Marion J; Lieberman, Isador H; Krebs, Viktor; Togawa, Daisuke; Fujishiro, Takaaki; Procop, Gary W

    2006-08-01

    We have developed a combined real-time PCR and pyrosequencing assay that successfully differentiated the vast majority of gram-positive and gram-negative bacteria when bacterial isolates were tested. The purpose of this study was to evaluate this assay on clinical specimens obtained from orthopedic surgeries, and to prospectively compare the results of "molecular Gram stain" with culture and conventional direct Gram stain. Forty-five surgical specimens were obtained from patients who underwent orthopedic surgery procedures. The DNA was extracted and a set of broad-range PCR primers that targeted a part of the 16S rDNA gene was used for pan-bacterial PCR. The amplicons were submitted for pyrosequencing and the resulting molecular Gram stain characteristics were recorded. Culture and direct Gram staining were performed using standard methods for all cases. Surgical specimens were reviewed histologically for all cases that had a discrepancy between culture and molecular results. There was an 86.7% (39/45) agreement between the traditional and molecular methods. In 12/14 (85.7%) culture-proven cases of bacterial infection, molecular Gram stain characteristics were in agreement with the culture results, while the conventional Gram stain result was in agreement only for five cases (35.7%). In the 31 culture negative cases, 27 cases were also PCR negative, whereas 4 were PCR positive. Three of these were characterized as gram negative and one as gram positive by this molecular method. Molecular determination of the Gram stain characteristics of bacteria that cause orthopedic infections may be achieved, in most instances, by this method. Further studies are necessary to understand the clinical importance of PCR-positive/culture-negative results.

  12. Cyclic Di-GMP Binding by an Assembly ATPase (PilB2) and Control of Type IV Pilin Polymerization in the Gram-Positive Pathogen Clostridium perfringens.

    Science.gov (United States)

    Hendrick, William A; Orr, Mona W; Murray, Samantha R; Lee, Vincent T; Melville, Stephen B

    2017-05-15

    The Gram-positive pathogen Clostridium perfringens possesses type IV pili (TFP), which are extracellular fibers that are polymerized from a pool of pilin monomers in the cytoplasmic membrane. Two proteins that are essential for pilus functions are an assembly ATPase (PilB) and an inner membrane core protein (PilC). Two homologues each of PilB and PilC are present in C. perfringens , called PilB1/PilB2 and PilC1/PilC2, respectively, along with four pilin proteins, PilA1 to PilA4. The gene encoding PilA2, which is considered the major pilin based on previous studies, is immediately downstream of the pilB2 and pilC2 genes. Purified PilB2 had ATPase activity, bound zinc, formed hexamers even in the absence of ATP, and bound the second messenger molecule cyclic di-GMP (c-di-GMP). Circular dichroism spectroscopy of purified PilC2 indicated that it retained its predicted degree of alpha-helical secondary structure. Even though no direct interactions between PilB2 and PilC2 could be detected in vivo or in vitro even in the presence of c-di-GMP, high levels of expression of a diguanylate cyclase from C. perfringens (CPE1788) stimulated polymerization of PilA2 in a PilB2- and PilC2-dependent manner. These results suggest that PilB2 activity is controlled by c-di-GMP levels in vivo but that PilB2-PilC2 interactions are either transitory or of low affinity, in contrast to results reported previously from in vivo studies of the PilB1/PilC1 pair in which PilC1 was needed for polar localization of PilB1. This is the first biochemical characterization of a c-di-GMP-dependent assembly ATPase from a Gram-positive bacterium. IMPORTANCE Type IV pili (TFP) are protein fibers involved in important bacterial functions, including motility, adherence to surfaces and host cells, and natural transformation. All clostridia whose genomes have been sequenced show evidence of the presence of TFP. The genetically tractable species Clostridium perfringens was used to study proteins involved in

  13. Enzyme-driven Bacillus spore coat degradation leading to spore killing.

    Science.gov (United States)

    Mundra, Ruchir V; Mehta, Krunal K; Wu, Xia; Paskaleva, Elena E; Kane, Ravi S; Dordick, Jonathan S

    2014-04-01

    The bacillus spore coat confers chemical and biological resistance, thereby protecting the core from harsh environments. The primarily protein-based coat consists of recalcitrant protein crosslinks that endow the coat with such functional protection. Proteases are present in the spore coat, which play a putative role in coat degradation in the environment. However these enzymes are poorly characterized. Nonetheless given the potential for proteases to catalyze coat degradation, we screened 10 commercially available proteases for their ability to degrade the spore coats of B. cereus and B. anthracis. Proteinase K and subtilisin Carlsberg, for B. cereus and B. anthracis spore coats, respectively, led to a morphological change in the otherwise impregnable coat structure, increasing coat permeability towards cortex lytic enzymes such as lysozyme and SleB, thereby initiating germination. Specifically in the presence of lysozyme, proteinase K resulted in 14-fold faster enzyme induced germination and exhibited significantly shorter lag times, than spores without protease pretreatment. Furthermore, the germinated spores were shown to be vulnerable to a lytic enzyme (PlyPH) resulting in effective spore killing. The spore surface in response to proteolytic degradation was probed using scanning electron microscopy (SEM), which provided key insights regarding coat degradation. The extent of coat degradation and spore killing using this enzyme-based pretreatment approach is similar to traditional, yet far harsher, chemical decoating methods that employ detergents and strong denaturants. Thus the enzymatic route reduces the environmental burden of chemically mediated spore killing, and demonstrates that a mild and environmentally benign biocatalytic spore killing is achievable. © 2013 Wiley Periodicals, Inc.

  14. Initiation of chromosomal replication in predatory bacterium Bdellovibrio bacteriovorus

    Directory of Open Access Journals (Sweden)

    Lukasz Makowski

    2016-11-01

    Full Text Available Bdellovibrio bacteriovorus is a small Gram-negative predatory bacterium that attacks other Gram-negative bacteria, including many animal, human, and plant pathogens. This bacterium exhibits a peculiar biphasic life cycle during which two different types of cells are produced: non-replicating highly motile cells (the free-living phase and replicating cells (the intracellular-growth phase. The process of chromosomal replication in B. bacteriovorus must therefore be temporally and spatially regulated to ensure that it is coordinated with cell differentiation and cell cycle progression. Recently, B. bacteriovorus has received considerable research interest due to its intriguing life cycle and great potential as a prospective antimicrobial agent. Although we know that chromosomal replication in bacteria is mainly regulated at the initiation step, no data exists about this process in B. bacteriovorus. We report the first characterization of key elements of initiation of chromosomal replication – DnaA protein and oriC region from the predatory bacterium, B. bacteriovorus. In vitro studies using different approaches demonstrate that the B. bacteriovorus oriC (BdoriC is specifically bound and unwound by the DnaA protein. Sequence comparison of the DnaA-binding sites enabled us to propose a consensus sequence for the B. bacteriovorus DnaA box (5’-NN(A/TTCCACA-3’. Surprisingly, in vitro analysis revealed that BdoriC is also bound and unwound by the host DnaA proteins (relatively distantly related from B. bacteriovorus. We compared the architecture of the DnaA–oriC complexes (orisomes in homologous (oriC and DnaA from B. bacteriovorus and heterologous (BdoriC and DnaA from prey, E. coli or P. aeruginosa systems. This work provides important new entry points toward improving our understanding of the initiation of chromosomal replication in this predatory bacterium.

  15. Fate of ingested Clostridium difficile spores in mice.

    Directory of Open Access Journals (Sweden)

    Amber Howerton

    Full Text Available Clostridium difficile infection (CDI is a leading cause of antibiotic-associated diarrhea, a major nosocomial complication. The infective form of C. difficile is the spore, a dormant and resistant structure that forms under stress. Although spore germination is the first committed step in CDI onset, the temporal and spatial distribution of ingested C. difficile spores is not clearly understood. We recently reported that CamSA, a synthetic bile salt analog, inhibits C. difficile spore germination in vitro and in vivo. In this study, we took advantage of the anti-germination activity of bile salts to determine the fate of ingested C. difficile spores. We tested four different bile salts for efficacy in preventing CDI. Since CamSA was the only anti-germinant tested able to prevent signs of CDI, we characterized CamSa's in vitro stability, distribution, and cytotoxicity. We report that CamSA is stable to simulated gastrointestinal (GI environments, but will be degraded by members of the natural microbiota found in a healthy gut. Our data suggest that CamSA will not be systemically available, but instead will be localized to the GI tract. Since in vitro pharmacological parameters were acceptable, CamSA was used to probe the mouse model of CDI. By varying the timing of CamSA dosage, we estimated that C. difficile spores germinated and established infection less than 10 hours after ingestion. We also showed that ingested C. difficile spores rapidly transited through the GI tract and accumulated in the colon and cecum of CamSA-treated mice. From there, C. difficile spores were slowly shed over a 96-hour period. To our knowledge, this is the first report of using molecular probes to obtain disease progression information for C. difficile infection.

  16. Demequina lutea sp. nov., isolated from a high Arctic permafrost soil

    DEFF Research Database (Denmark)

    Finster, Kai; Herbert, Rodney Andrew; Kjeldsen, Kasper Urup

    2009-01-01

    Two Gram-stain-positive, pigmented, non-motile, non-spore-forming, pleomorphic, rod-shaped bacteria (strains SV45T and SV47), isolated from a permafrost soil collected from the Adventdalen valley, Spitsbergen, northern Norway, have been characterized taxonomically using a polyphasic approach...

  17. Clostridium botulinum group I strain genotyping by 15-locus multilocus variable-number tandem-repeat analysis

    NARCIS (Netherlands)

    Fillo, S.; Giordani, F.; Anniballi, F.; Gorgé, O.; Ramisse, V.; Vergnaud, G.; Riehm, J.M.; Scholz, H.C.; Splettstoesser, W.D.; Kieboom, J.; Olsen, J.-S.; Fenicia, L.; Lista, F.

    2011-01-01

    Clostridium botulinum is a taxonomic designation that encompasses a broad variety of spore-forming, Gram-positive bacteria producing the botulinum neurotoxin (BoNT). C. botulinum is the etiologic agent of botulism, a rare but severe neuroparalytic disease. Fine-resolution genetic characterization of

  18. The rapid isolation of mutants of some Gram-positive bacteria

    International Nuclear Information System (INIS)

    Dijkhuizen, L.; Keijer, L.

    1981-01-01

    In this communication the authors describe a method for isolating at high frequency independent mutants of a number of Gram-positive bacteria. The method was originally developed for use with an Arthrobacter sp. and appears to work best with this and other coryneform bacteria. All the bacteria used were from the culture collections maintained at the University of Warwick or the Centre for Applied Microbiological Research. For mutagenesis using UV light, cells were grown in complex media and used while still in the logarithmic phase of growth. Details of the irradiation procedure are given in the text. (Auth.)

  19. The Mechanisms of Virulence Regulation by Small Noncoding RNAs in Low GC Gram-Positive Pathogens

    Directory of Open Access Journals (Sweden)

    Stephanie Pitman

    2015-12-01

    Full Text Available The discovery of small noncoding regulatory RNAs (sRNAs in bacteria has grown tremendously recently, giving new insights into gene regulation. The implementation of computational analysis and RNA sequencing has provided new tools to discover and analyze potential sRNAs. Small regulatory RNAs that act by base-pairing to target mRNAs have been found to be ubiquitous and are the most abundant class of post-transcriptional regulators in bacteria. The majority of sRNA studies has been limited to E. coli and other gram-negative bacteria. However, examples of sRNAs in gram-positive bacteria are still plentiful although the detailed gene regulation mechanisms behind them are not as well understood. Strict virulence control is critical for a pathogen’s survival and many sRNAs have been found to be involved in that process. This review outlines the targets and currently known mechanisms of trans-acting sRNAs involved in virulence regulation in various gram-positive pathogens. In addition, their shared characteristics such as CU interaction motifs, the role of Hfq, and involvement in two-component regulators, riboswitches, quorum sensing, or toxin/antitoxin systems are described.

  20. Effect of silver/copper and copper oxide nanoparticle powder on growth of Gram-negative and Gram-positive bacteria and their toxicity against the normal human dermal fibroblasts

    International Nuclear Information System (INIS)

    Peszke, Jerzy; Nowak, Anna; Szade, Jacek; Szurko, Agnieszka; Zygadło, Dorota; Michałowska, Marlena; Krzyściak, Paweł; Zygoń, Patrycja; Ratuszna, Alicja; Ostafin, Marek M.

    2016-01-01

    Engineered nanomaterials, especially metallic nanoparticles, are the most popular system applied in daily life products. The study of their biological and toxicity properties seems to be indispensable. In this paper, we present results of biological activity of Ag/Cu nanoparticles. These nanoparticles show more promising killing/inhibiting properties on Gram-negative bacteria than for Gram-positive ones. The Gram-negative bacteria show strong effect already at the concentration of 1 ppm after 15 min of incubation. Moreover, in vitro tests of toxicity made on normal human dermal fibroblast cultures showed that after 72 h of incubation with Ag/Cu nanoparticles, they are less toxic then Cu 2 O/CuO nanoparticles.

  1. Effect of silver/copper and copper oxide nanoparticle powder on growth of Gram-negative and Gram-positive bacteria and their toxicity against the normal human dermal fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Peszke, Jerzy; Nowak, Anna, E-mail: ana.maria.nowak@gmail.com; Szade, Jacek; Szurko, Agnieszka; Zygadło, Dorota; Michałowska, Marlena [University of Silesia, A. Chelkowski Institute of Physics (Poland); Krzyściak, Paweł [Jagiellonian University Medical College, Department of Mycology Chair of Microbiology (Poland); Zygoń, Patrycja [Czestochowa University of Technology, Institute of Materials Engineering (Poland); Ratuszna, Alicja [University of Silesia, A. Chelkowski Institute of Physics (Poland); Ostafin, Marek M. [Department of Microbiology University of Agriculture (Poland)

    2016-12-15

    Engineered nanomaterials, especially metallic nanoparticles, are the most popular system applied in daily life products. The study of their biological and toxicity properties seems to be indispensable. In this paper, we present results of biological activity of Ag/Cu nanoparticles. These nanoparticles show more promising killing/inhibiting properties on Gram-negative bacteria than for Gram-positive ones. The Gram-negative bacteria show strong effect already at the concentration of 1 ppm after 15 min of incubation. Moreover, in vitro tests of toxicity made on normal human dermal fibroblast cultures showed that after 72 h of incubation with Ag/Cu nanoparticles, they are less toxic then Cu{sub 2}O/CuO nanoparticles.

  2. Spore formation and toxin production in Clostridium difficile biofilms.

    Science.gov (United States)

    Semenyuk, Ekaterina G; Laning, Michelle L; Foley, Jennifer; Johnston, Pehga F; Knight, Katherine L; Gerding, Dale N; Driks, Adam

    2014-01-01

    The ability to grow as a biofilm can facilitate survival of bacteria in the environment and promote infection. To better characterize biofilm formation in the pathogen Clostridium difficile, we established a colony biofilm culture method for this organism on a polycarbonate filter, and analyzed the matrix and the cells in biofilms from a variety of clinical isolates over several days of biofilm culture. We found that biofilms readily formed in all strains analyzed, and that spores were abundant within about 6 days. We also found that extracellular DNA (eDNA), polysaccharide and protein was readily detected in the matrix of all strains, including the major toxins A and/or B, in toxigenic strains. All the strains we analyzed formed spores. Apart from strains 630 and VPI10463, which sporulated in the biofilm at relatively low frequencies, the frequencies of biofilm sporulation varied between 46 and 65%, suggesting that variations in sporulation levels among strains is unlikely to be a major factor in variation in the severity of disease. Spores in biofilms also had reduced germination efficiency compared to spores obtained by a conventional sporulation protocol. Transmission electron microscopy revealed that in 3 day-old biofilms, the outermost structure of the spore is a lightly staining coat. However, after 6 days, material that resembles cell debris in the matrix surrounds the spore, and darkly staining granules are closely associated with the spores surface. In 14 day-old biofilms, relatively few spores are surrounded by the apparent cell debris, and the surface-associated granules are present at higher density at the coat surface. Finally, we showed that biofilm cells possess 100-fold greater resistance to the antibiotic metronidazole then do cells cultured in liquid media. Taken together, our data suggest that C. difficile cells and spores in biofilms have specialized properties that may facilitate infection.

  3. Spore formation and toxin production in Clostridium difficile biofilms.

    Directory of Open Access Journals (Sweden)

    Ekaterina G Semenyuk

    Full Text Available The ability to grow as a biofilm can facilitate survival of bacteria in the environment and promote infection. To better characterize biofilm formation in the pathogen Clostridium difficile, we established a colony biofilm culture method for this organism on a polycarbonate filter, and analyzed the matrix and the cells in biofilms from a variety of clinical isolates over several days of biofilm culture. We found that biofilms readily formed in all strains analyzed, and that spores were abundant within about 6 days. We also found that extracellular DNA (eDNA, polysaccharide and protein was readily detected in the matrix of all strains, including the major toxins A and/or B, in toxigenic strains. All the strains we analyzed formed spores. Apart from strains 630 and VPI10463, which sporulated in the biofilm at relatively low frequencies, the frequencies of biofilm sporulation varied between 46 and 65%, suggesting that variations in sporulation levels among strains is unlikely to be a major factor in variation in the severity of disease. Spores in biofilms also had reduced germination efficiency compared to spores obtained by a conventional sporulation protocol. Transmission electron microscopy revealed that in 3 day-old biofilms, the outermost structure of the spore is a lightly staining coat. However, after 6 days, material that resembles cell debris in the matrix surrounds the spore, and darkly staining granules are closely associated with the spores surface. In 14 day-old biofilms, relatively few spores are surrounded by the apparent cell debris, and the surface-associated granules are present at higher density at the coat surface. Finally, we showed that biofilm cells possess 100-fold greater resistance to the antibiotic metronidazole then do cells cultured in liquid media. Taken together, our data suggest that C. difficile cells and spores in biofilms have specialized properties that may facilitate infection.

  4. Pseudomonas aestus sp. nov., a plant growth-promoting bacterium isolated from mangrove sediments.

    Science.gov (United States)

    Vasconcellos, Rafael L F; Santos, Suikinai Nobre; Zucchi, Tiago Domingues; Silva, Fábio Sérgio Paulino; Souza, Danilo Tosta; Melo, Itamar Soares

    2017-10-01

    Strain CMAA 1215 T , a Gram-reaction-negative, aerobic, catalase positive, polarly flagellated, motile, rod-shaped (0.5-0.8 × 1.3-1.9 µm) bacterium, was isolated from mangrove sediments, Cananéia Island, Brazil. Analysis of the 16S rRNA gene sequences showed that strain CMAA 1215 T forms a distinct phyletic line within the Pseudomonas putida subclade, being closely related to P. plecoglossicida ATCC 700383 T , P. monteilii NBRC 103158 T , and P. taiwanensis BCRC 17751 T of sequence similarity of 98.86, 98.73, and 98.71%, respectively. Genomic comparisons of the strain CMAA 1215 T with its closest phylogenetic type strains using average nucleotide index (ANI) and DNA:DNA relatedness approaches revealed 84.3-85.3% and 56.0-63.0%, respectively. A multilocus sequence analysis (MLSA) performed concatenating 16S rRNA, gyrB and rpoB gene sequences from the novel species was related with Pseudomonas putida subcluster and formed a new phylogenetic lineage. The phenotypic, physiological, biochemical, and genetic characteristics support the assignment of CMAA 1215 T to the genus Pseudomonas, representing a novel species. The name Pseudomonas aestus sp.nov. is proposed, with CMAA 1215 T (=NRRL B-653100 T  = CBMAI 1962 T ) as the type strain.

  5. Experience With Rapid Microarray-Based Diagnostic Technology and Antimicrobial Stewardship for Patients With Gram-Positive Bacteremia.

    Science.gov (United States)

    Neuner, Elizabeth A; Pallotta, Andrea M; Lam, Simon W; Stowe, David; Gordon, Steven M; Procop, Gary W; Richter, Sandra S

    2016-11-01

    OBJECTIVE To describe the impact of rapid diagnostic microarray technology and antimicrobial stewardship for patients with Gram-positive blood cultures. DESIGN Retrospective pre-intervention/post-intervention study. SETTING A 1,200-bed academic medical center. PATIENTS Inpatients with blood cultures positive for Staphylococcus aureus, Enterococcus faecalis, E. faecium, Streptococcus pneumoniae, S. pyogenes, S. agalactiae, S. anginosus, Streptococcus spp., and Listeria monocytogenes during the 6 months before and after implementation of Verigene Gram-positive blood culture microarray (BC-GP) with an antimicrobial stewardship intervention. METHODS Before the intervention, no rapid diagnostic technology was used or antimicrobial stewardship intervention was undertaken, except for the use of peptide nucleic acid fluorescent in situ hybridization and MRSA agar to identify staphylococcal isolates. After the intervention, all Gram-positive blood cultures underwent BC-GP microarray and the antimicrobial stewardship intervention consisting of real-time notification and pharmacist review. RESULTS In total, 513 patients with bacteremia were included in this study: 280 patients with S. aureus, 150 patients with enterococci, 82 patients with stretococci, and 1 patient with L. monocytogenes. The number of antimicrobial switches was similar in the pre-BC-GP (52%; 155 of 300) and post-BC-GP (50%; 107 of 213) periods. The time to antimicrobial switch was significantly shorter in the post-BC-GP group than in the pre-BC-GP group: 48±41 hours versus 75±46 hours, respectively (P<.001). The most common antimicrobial switch was de-escalation and time to de-escalation, was significantly shorter in the post-BC-GP group than in the pre-BC-GP group: 53±41 hours versus 82±48 hours, respectively (P<.001). There was no difference in mortality or hospital length of stay as a result of the intervention. CONCLUSIONS The combination of a rapid microarray diagnostic test with an antimicrobial

  6. Dehalogenimonas formicexedens sp. nov., a chlorinated alkane-respiring bacterium isolated from contaminated groundwater.

    Science.gov (United States)

    Key, Trent A; Bowman, Kimberly S; Lee, Imchang; Chun, Jongsik; Albuquerque, Luciana; da Costa, Milton S; Rainey, Fred A; Moe, William M

    2017-05-01

    A strictly anaerobic, Gram-stain-negative, non-spore-forming bacterium designated NSZ-14T, isolated from contaminated groundwater in Louisiana (USA), was characterized using a polyphasic approach. Strain NSZ-14T reductively dehalogenated a variety of polychlorinated aliphatic alkanes, producing ethene from 1,2-dichloroethane, propene from 1,2-dichloropropane, a mixture of cis- and trans-1,2-dichloroethene from 1,1,2,2-tetrachloroethane, vinyl chloride from 1,1,2-trichloroethane and allyl chloride (3-chloro-1-propene) from 1,2,3-trichloropropane. Formate or hydrogen could both serve as electron donors. Dechlorination occurred between pH 5.5 and 7.5 and over a temperature range of 20-37 °C. Major cellular fatty acids included C18 : 1ω9c, C14 : 0 and C16 : 0. 16S rRNA gene sequence-based phylogenetic analysis indicated that the strain clusters within the class Dehalococcoidia of the phylum Chloroflexi, most closely related to but distinct from type strains of the species Dehalogenimonas alkenigignens (97.63 % similarity) and Dehalogenimonas lykanthroporepellens (95.05 %). A complete genome sequence determined for strain NSZ-14T revealed a DNA G+C content of 53.96 mol%, which was corroborated by HPLC (54.1±0.2 mol% G+C). Genome-wide comparisons based on average nucleotide identity by orthology and estimated DNA-DNA hybridization values combined with phenotypic and chemotaxonomic traits and phylogenetic analysis indicate that strain NSZ-14T represents a novel species within the genus Dehalogenimonas, for which the name Dehalogenimonas formicexedens sp. nov. is proposed. The type strain is NSZ-14T (=HAMBI 3672T=JCM 19277T=VKM B-3058T). An emended description of Dehalogenimonas alkenigignens is also provided.

  7. Antimicrobial resistance in Gram-positive bacteria from Timorese River Buffalo (Bubalus bubalis) skin microbiota.

    Science.gov (United States)

    Oliveira, Manuela; Monteiro, José L; Rana, Sílvia; Vilela, Cristina L

    2010-06-01

    The Timorese River Buffalo (Bubalus bubalis) plays a major role in the East Timor economy, as it is an important source of animal protein in human nutrition. They are widely spread throughout the country and are in direct contact with the populations. In spite of this proximity, information on their microbiota is scarce. This work aimed at characterizing the skin microbiota of the East Timorese River Buffalo and its antimicrobial resistance profile. Skin swab samples were taken from 46 animals in surveys conducted in three farms located in "Suco de Nairete", Lospalos district, during July and August 2006. Bacteria were isolated and identified according to conventional microbiological procedures. A total of 456 isolates were obtained, including Gram-positive (n = 243) and Gram-negative (n = 213) bacteria. Due to their importance as potential pathogens and as vehicles for antimicrobial resistance transmission, Gram-positive cocci (n = 27) and bacilli (n = 77) isolates were further characterized, and their antimicrobial resistance profile determined by the disk diffusion method according to the Clinical and Laboratory Standards Institute guidelines. This study shows the high bacterial diversity of B. bubalis skin microbiota, representing an important first step towards understanding its importance and epidemiologic role in animal health. It also points out the potential role of these animals as vectors of antimicrobial resistant bacteria dissemination and the importance of antimicrobial resistance monitoring in developing countries.

  8. Bacillus endozanthoxylicus sp. nov., an endophytic bacterium isolated from Zanthoxylum bungeanum Maxim leaves.

    Science.gov (United States)

    Ma, Li; Xi, Jia-Qin; Cao, Yong-Hong; Wang, Xiao-Yan; Zheng, Shuai-Chao; Yang, Cheng-Gang; Yang, Ling-Ling; Mi, Qi-Li; Li, Xue-Mei; Zhu, Ming-Liang; Mo, Ming-He

    2017-10-01

    A Gram-stain-positive, rod-shaped, motile bacterium, designated as 1404 T , was isolated from leaves of Chinese red pepper (Huajiao) (Zanthoxylum bungeanum Maxim) collected from Gansu, north-west China. Spores were not observed under a range of conditions. Strain 1404 T was observed to grow at 15-45 °C and pH 6.0-10.0 and in presence of 0-5 % (w/v) NaCl concentration. The cell wall of strain 1404 T was found to contain meso-diaminopimelic acid, and the predominant respiratory quinone was identified as MK-7. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an unidentified phospholipid as well as three unidentified polar lipids. The major fatty acids profile of strain 1404 T consisted of iso-C15 : 0 (25.6 %), anteiso-C15 : 0 (18.4 %) and iso-C14 : 0 (12.1 %). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain 1404 T was affiliated to the genus Bacillus and was closely related to Bacillusoryzisoli 1DS3-10 T , Bacillusbenzoevorans DSM 5391 T and Bacilluscirculans DSM 11 T with sequence similarity of 98.3, 98.2 and 96.9 %, respectively. The G+C content of the genomic DNA was determined to be 39.4 mol%. DNA-DNA hybridization values indicated that relatedness between strain 1404 T and the type strains of closely related species of the genus Bacillus was below 41 %. Therefore, on the basis of the data from the polyphasic taxonomic study presented, strain 1404 T represents a novel species of the genus Bacillus, for which the name proposed is Bacillus endozanthoxylicus sp. nov. The type strain is 1404 T (=CCTCC AB 2017021 T =KCTC 33827 T ).

  9. Chitin Degradation Proteins Produced by the Marine Bacterium Vibrio harveyi Growing on Different Forms of Chitin.

    Science.gov (United States)

    Svitil, A L; Chadhain, S; Moore, J A; Kirchman, D L

    1997-02-01

    Relatively little is known about the number, diversity, and function of chitinases produced by bacteria, even though chitin is one of the most abundant polymers in nature. Because of the importance of chitin, especially in marine environments, we examined chitin-degrading proteins in the marine bacterium Vibrio harveyi. This bacterium had a higher growth rate and more chitinase activity when grown on (beta)-chitin (isolated from squid pen) than on (alpha)-chitin (isolated from snow crab), probably because of the more open structure of (beta)-chitin. When exposed to different types of chitin, V. harveyi excreted several chitin-degrading proteins into the culture media. Some chitinases were present with all of the tested chitins, while others were unique to a particular chitin. We cloned and identified six separate chitinase genes from V. harveyi. These chitinases appear to be unique based on DNA restriction patterns, immunological data, and enzyme activity. This marine bacterium and probably others appear to synthesize separate chitinases for efficient utilization of different forms of chitin and chitin by-products.

  10. New crystal forms of NTPDase1 from the bacterium Legionella pneumophila

    International Nuclear Information System (INIS)

    Zebisch, Matthias; Schäfer, Petra; Lauble, Peter; Sträter, Norbert

    2013-01-01

    The soluble NTPDase1 from L. pneumophila was crystallized in six crystal forms and the structure was solved using a sulfur SAD approach. Nucleoside triphosphate diphosphohydrolases (NTPDases) are a large class of nucleotidases that hydrolyze the (γ/β)- and (β/α)-anhydride bonds of nucleoside triphosphates and diphosphates, respectively. NTPDases are found throughout the eukaryotic domain. In addition, a very small number of members can be found in bacteria, most of which live as parasites of eukaryotic hosts. NTPDases of intracellular and extracellular parasites are emerging as important regulators for the survival of the parasite. To deepen the knowledge of the structure and function of this enzyme class, recombinant production of the NTPDase1 from the bacterium Legionella pneumophila has been established. The protein could be crystallized in six crystal forms, of which one has been described previously. The crystals diffracted to resolutions of between 1.4 and 2.5 Å. Experimental phases determined by a sulfur SAD experiment using an orthorhombic crystal form produced an interpretable electron-density map

  11. Distinction of Gram-positive and -negative bacteria using a colorimetric microbial viability assay based on the reduction of water-soluble tetrazolium salts with a selection medium.

    Science.gov (United States)

    Tsukatani, Tadayuki; Suenaga, Hikaru; Higuchi, Tomoko; Shiga, Masanobu; Noguchi, Katsuya; Matsumoto, Kiyoshi

    2011-01-01

    Bacteria are fundamentally divided into two groups: Gram-positive and Gram-negative. Although the Gram stain and other techniques can be used to differentiate these groups, some issues exist with traditional approaches. In this study, we developed a method for differentiating Gram-positive and -negative bacteria using a colorimetric microbial viability assay based on the reduction of the tetrazolium salt {2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt} (WST-8) via 2-methyl-1,4-napthoquinone with a selection medium. We optimized the composition of the selection medium to allow the growth of Gram-negative bacteria while inhibiting the growth of Gram-positive bacteria. When the colorimetric viability assay was carried out in a selection medium containing 0.5µg/ml crystal violet, 5.0 µg/ml daptomycin, and 5.0µg/ml vancomycin, the reduction in WST-8 by Gram-positive bacteria was inhibited. On the other hand, Gram-negative bacteria produced WST-8-formazan in the selection medium. The proposed method was also applied to determine the Gram staining characteristics of bacteria isolated from various foodstuffs. There was good agreement between the results obtained using the present method and those obtained using a conventional staining method. These results suggest that the WST-8 colorimetric assay with selection medium is a useful technique for accurately differentiating Gram-positive and -negative bacteria.

  12. Protection of Bacillus pumilus spores by catalases.

    Science.gov (United States)

    Checinska, Aleksandra; Burbank, Malcolm; Paszczynski, Andrzej J

    2012-09-01

    Bacillus pumilus SAFR-032, isolated at spacecraft assembly facilities of the National Aeronautics and Space Administration Jet Propulsion Laboratory, is difficult to kill by the sterilization method of choice, which uses liquid or vapor hydrogen peroxide. We identified two manganese catalases, YjqC and BPUM_1305, in spore protein extracts of several B. pumilus strains by using PAGE and mass spectrometric analyses. While the BPUM_1305 catalase was present in six of the B. pumilus strains tested, YjqC was not detected in ATCC 7061 and BG-B79. Furthermore, both catalases were localized in the spore coat layer along with laccase and superoxide dismutase. Although the initial catalase activity in ATCC 7061 spores was higher, it was less stable over time than the SAFR-032 enzyme. We propose that synergistic activity of YjqC and BPUM_1305, along with other coat oxidoreductases, contributes to the enhanced resistance of B. pumilus spores to hydrogen peroxide. We observed that the product of the catalase reaction, gaseous oxygen, forms expanding vesicles on the spore surface, affecting the mechanical integrity of the coat layer, resulting in aggregation of the spores. The accumulation of oxygen gas and aggregations may play a crucial role in limiting further exposure of Bacilli spore surfaces to hydrogen peroxide or other toxic chemicals when water is present.

  13. Diversity and abundance of sulfate-reducing microorganisms in the sulfate and methane zones of a marine sediment, Black Sea RID A-8182-2008

    DEFF Research Database (Denmark)

    Leloup, Julie; Loy, Alexander; Knab, Nina J.

    2007-01-01

    branching sequences which might represent Gram-positive spore-forming sulfate- and/or sulfite-reducing microorganisms. We thus hypothesize that terminal carbon mineralization in surface sediments of the Black Sea is largely due to the sulfate reduction activity of previously hidden SRM. Although these novel...

  14. Secretory phospholipase A2 in dromedary tears: a host defense against staphylococci and other gram-positive bacteria.

    Science.gov (United States)

    Ben Bacha, Abir; Abid, Islem

    2013-03-01

    The best known physiologic function of secreted phospholipase A2 (sPLA2) group IIA (sPLA2-IIA) is defense against bacterial infection through hydrolytic degradation of bacterial membrane phospholipids. In fact, sPLA2-IIA effectively kills Gram-positive bacteria and to a lesser extent Gram-negative bacteria and is considered a major component of the eye's innate immune defense system. The antibacterial properties of sPLA2 have been demonstrated in rabbit and human tears. In this report, we have analyzed the bactericidal activity of dromedary tears and the subsequently purified sPLA2 on several Gram-positive bacteria. Our results showed that the sPLA2 displays a potent bactericidal activity against all the tested bacteria particularly against the Staphylococcus strains when tested in the ionic environment of tears. There is a synergic action of the sPLA2 with lysozyme when added to the bacteria culture prior to sPLA2. Interestingly, lysozyme purified from dromedary tears showed a significant bactericidal activity against Listeria monocytogene and Staphylococcus epidermidis, whereas the one purified from human tears displayed no activity against these two strains. We have also demonstrated that Ca(2+) is crucial for the activity of dromedary tear sPLA2 and to a less extent Mg(2+) ions. Given the presence of sPLA2 in tears and intestinal secretions, this enzyme may play a substantial role in innate mucosal and systemic bactericidal defenses against Gram-positive bacteria.

  15. The study of antibacterial activity and stability of dyed cotton fabrics modified with different forms of silver

    Directory of Open Access Journals (Sweden)

    Lazić Vesna

    2012-01-01

    Full Text Available This study compares the effect of colloidal silver nanoparticles and commercial RUCO-BAC AGP agent with silver chloride as an active component on antibacterial activity of dyed cotton fabrics. Cotton fabrics were dyed with vat dyes Bezanthren olive T and Bezanthren grey FFB. Antibacterial activity of silver loaded dyed cotton fabrics was tested against Gram-positive bacterium Staphylococcus aureus and Gram-negative bacterium Escherichia coli. Unlike RUCO-BAC AGP synthesized silver nanoparticles deposited onto dyed cotton fabrics provided maximum bacteria reduction independently of applied dye. The stability of modified cotton fabrics was analyzed in artificial sweat at pH 5.5 and 8.0. Approximately the same amount of silver was released from differently modified cotton fabrics in artificial sweat. Larger amount of silver was released in the sweat at pH 8.0.

  16. The origin of a derived superkingdom: how a gram-positive bacterium crossed the desert to become an archaeon

    Directory of Open Access Journals (Sweden)

    Bourne Philip E

    2011-02-01

    Full Text Available Abstract Background The tree of life is usually rooted between archaea and bacteria. We have previously presented three arguments that support placing the root of the tree of life in bacteria. The data have been dismissed because those who support the canonical rooting between the prokaryotic superkingdoms cannot imagine how the vast divide between the prokaryotic superkingdoms could be crossed. Results We review the evidence that archaea are derived, as well as their biggest differences with bacteria. We argue that using novel data the gap between the superkingdoms is not insurmountable. We consider whether archaea are holophyletic or paraphyletic; essential to understanding their origin. Finally, we review several hypotheses on the origins of archaea and, where possible, evaluate each hypothesis using bioinformatics tools. As a result we argue for a firmicute ancestry for archaea over proposals for an actinobacterial ancestry. Conclusion We believe a synthesis of the hypotheses of Lake, Gupta, and Cavalier-Smith is possible where a combination of antibiotic warfare and viral endosymbiosis in the bacilli led to dramatic changes in a bacterium that resulted in the birth of archaea and eukaryotes. Reviewers This article was reviewed by Patrick Forterre, Eugene Koonin, and Gáspár Jékely

  17. Characterization of a Neochlamydia-like Bacterium Associated with Epitheliocystis in Cultured Artic Char Salvelinus alpinus

    Science.gov (United States)

    Infections of branchial epithelium by intracellular gram-negative bacteria, termed epitheliocystis, have limited culture of Arctic char (Salvelinus alpinus). To characterize a bacterium associated with epitheliocystis in cultured char, gills were sampled for histopathologic examination, conventional...

  18. Colwellia agarivorans sp. nov., an agar-digesting marine bacterium isolated from coastal seawater

    Science.gov (United States)

    A novel Gram-stain-negative, facultatively anaerobic, yellowish and agar-digesting marine bacterium, designated strain QM50**T, was isolated from coastal seawater in an aquaculture site near Qingdao, China. Phylogenetic analysis based on 16S rDNA sequences revealed that the novel isolate represented...

  19. Treatment of gram-positive deep sternal wound infections in cardiac surgery -experiences with daptomycin-

    Directory of Open Access Journals (Sweden)

    Coskun Kasim O

    2011-09-01

    Full Text Available Abstract The reported incidence of deep sternal wound infection (DSWI after cardiac surgery is 0.4-5% with Staphylococcus aureus being the most common pathogen isolated from infected wound sternotomies and bacteraemic blood cultures. This infection is associated with a higher morbidity and mortality than other known aetiologies. Little is reported about the optimal antibiotic management. The aim of the study is to quantify the application of daptomycin treatment of DSWI due to gram-positive organisms post cardiac surgery. We performed an observational analysis in 23 cases of post sternotomy DSWI with gram-positive organisms February 2009 and September 2010. When the wound appeared viable and the microbiological cultures were negative, the technique of chest closure was individualised to the patient. The incidence of DSWI was 1.46%. The mean dose of daptomycin application was 4.4 ± 0.9 mg/kg/d and the average duration of the daptomycin application was 14.47 ± 7.33 days. In 89% of the patients VAC therapy was used. The duration from daptomycin application to sternal closure was 18 ± 13.9 days. The parameters of infection including, fibrinogen (p = 0.03, white blood cell count (p = 0.001 and C-reactive protein (p = 0.0001 were significantly reduced after daptomycin application. We had no mortality and wound healing was successfully achieved in all patients. Treatment of DSWI due to gram-positive organisms with a daptomycin-containing antibiotic regimen is safe, effective and promotes immediate improvement of local wound conditions. Based on these observations, daptomycin may offer a new treatment option for expediting surgical management of DSWI after cardiac surgery.

  20. Administration of Brevibacillus laterosporus spores as a poultry feed additive to inhibit house fly development in feces: a new eco-sustainable concept.

    Science.gov (United States)

    Ruiu, L; Satta, A; Floris, I

    2014-03-01

    The success of a microbial pesticide application against house flies developing in manure should accomplish the uniform mixing of active ingredients with this breeding medium, thus enhancing residual effects. The oral administration of the entomopathogenic bacterium Brevibacillus laterosporus to caged poultry species allows the homogeneous incorporation of its active ingredients with fly breeding media. Feces from treated broilers or hens show toxicity against exposed fly adults and larvae. Insecticidal effects are concentration-dependent with a lethal median concentration (LC50) value of 1.34 × 10(8) and 0.61 × 10(8) spores/g of feces for adults and larvae, respectively. Manure toxicity against flies was maintained as long as chickens were fed a diet containing adequate concentrations of B. laterosporus spores. Toxicity significantly decreased after spore administration to birds was interrupted. When poultry diet contained 10(10) spores/g, mortality of flies reared on feces exceeded 80%. The use of B. lateroporus spores as a feed additive in poultry production systems fostering a more integrated approach to farming is discussed.

  1. Atmospheric mold spore counts in relation to meteorological parameters

    Science.gov (United States)

    Katial, R. K.; Zhang, Yiming; Jones, Richard H.; Dyer, Philip D.

    Fungal spore counts of Cladosporium, Alternaria, and Epicoccum were studied during 8 years in Denver, Colorado. Fungal spore counts were obtained daily during the pollinating season by a Rotorod sampler. Weather data were obtained from the National Climatic Data Center. Daily averages of temperature, relative humidity, daily precipitation, barometric pressure, and wind speed were studied. A time series analysis was performed on the data to mathematically model the spore counts in relation to weather parameters. Using SAS PROC ARIMA software, a regression analysis was performed, regressing the spore counts on the weather variables assuming an autoregressive moving average (ARMA) error structure. Cladosporium was found to be positively correlated (Pmodel was derived for Cladosporium spore counts using the annual seasonal cycle and significant weather variables. The model for Alternaria and Epicoccum incorporated the annual seasonal cycle. Fungal spore counts can be modeled by time series analysis and related to meteorological parameters controlling for seasonallity; this modeling can provide estimates of exposure to fungal aeroallergens.

  2. Marine Bacteria from Danish Coastal Waters Show Antifouling Activity against the Marine Fouling Bacterium Pseudoalteromonas sp. Strain S91 and Zoospores of the Green Alga Ulva australis Independent of Bacteriocidal Activity

    DEFF Research Database (Denmark)

    Bernbom, Nete; Ng, Yoke Yin; Kjelleberg, Staffan

    2011-01-01

    , representing the major taxonomic groups, different seasons, and isolation strategies, were tested for antiadhesive effect against the marine biofilm-forming bacterium Pseudoalteromonas sp. strain S91 and zoospores of the green alga Ulva australis. The antiadhesive effects were assessed by quantifying...... the number of strain S91 or Ulva spores attaching to a preformed biofilm of each of the 22 strains. The strongest antifouling activity was found in Pseudoalteromonas strains. Biofilms of Pseudoalteromonas piscicida, Pseudoalteromonas tunicata, and Pseudoalteromonas ulvae prevented Pseudoalteromonas S91 from...

  3. The role of heat resistance in thermorestoration of hydrated bacterial spores

    International Nuclear Information System (INIS)

    Friedman, Y.S.; Grecz, N.

    1973-01-01

    This study for the first time presents evidence of the distinct role played in thermorestoration by cellular determinants such as the resistance to heat and radiation, and the ionic state of spores. In the past only radiochemical determinants associated with radical annealment have been studied in hydrated systems. The basic heat resistance of spores plays a significant role in the precipitous drop in spore survival due to 0.45 Mrad radiation plus heat above 65-75 0 C for B.cereus and 75-95 0 C for B.stearothermophilus. The effect of the spores radiation resistance was not distinct except in the frozen state and at the saturation plateau of thermorestoration where the radiation resistant B.cereus showed ca. 1 log cycle higher survival than the radiation sensitive B.stearothermophilus. When spores are chemically converted into their H + and Ca ++ ionic forms, the H + spores are distinctly more responsive than Ca ++ spores to processes of radical annealment responsible for thermorestoration in hydrated spore systems. At temperatures of extensive thermorestoration of water radicals, H + spores showed higher survival than Ca ++ spores. (F.J.)

  4. Bacillus nealsonii sp. nov., isolated from a spacecraft-assembly facility, whose spores are gamma-radiation resistant

    Science.gov (United States)

    Venkateswaran, Kasthuri; Kempf, Michael; Chen, Fei; Satomi, Masataka; Nicholson, Wayne; Kern, Roger

    2003-01-01

    One of the spore-formers isolated from a spacecraft-assembly facility, belonging to the genus Bacillus, is described on the basis of phenotypic characterization, 16S rDNA sequence analysis and DNA-DNA hybridization studies. It is a Gram-positive, facultatively anaerobic, rod-shaped eubacterium that produces endospores. The spores of this novel bacterial species exhibited resistance to UV, gamma-radiation, H2O2 and desiccation. The 18S rDNA sequence analysis revealed a clear affiliation between this strain and members of the low G+C Firmicutes. High 16S rDNA sequence similarity values were found with members of the genus Bacillus and this was supported by fatty acid profiles. The 16S rDNA sequence similarity between strain FO-92T and Bacillus benzoevorans DSM 5391T was very high. However, molecular characterizations employing small-subunit 16S rDNA sequences were at the limits of resolution for the differentiation of species in this genus, but DNA-DNA hybridization data support the proposal of FO-92T as Bacillus nealsonii sp. nov. (type strain is FO-92T =ATCC BAAM-519T =DSM 15077T).

  5. Size matters for violent discharge height and settling speed of Sphagnum spores: important attributes for dispersal potential.

    Science.gov (United States)

    Sundberg, Sebastian

    2010-02-01

    Initial release height and settling speed of diaspores are biologically controlled components which are key to modelling wind dispersal. Most Sphagnum (peat moss) species have explosive spore liberation. In this study, how capsule and spore sizes affect the height to which spores are propelled were measured, and how spore size and spore number of discharged particles relate to settling speed in the aspherical Sphagnum spores. Spore discharge and spore cloud development were filmed in a closed chamber (nine species). Measurements were taken from snapshots at three stages of cloud development. Settling speed of spores (14 species) and clusters were timed in a glass tube. The maximum discharge speed measured was 3.6 m s(-1). Spores reached a maximum height of 20 cm (average: 15 cm) above the capsule. The cloud dimensions at all stages were related positively to capsule size (R(2) = 0.58-0.65). Thus species with large shoots (because they have large capsules) have a dispersal advantage. Half of the spores were released as singles and the rest as clusters (usually two to four spores). Single spores settled at 0.84-1.86 cm s(-1), about 52 % slower than expected for spherical spores with the same diameters. Settling speed displayed a positive curvilinear relationship with spore size, close to predictions by Stokes' law for spherical spores with 68 % of the actual diameters. Light-coloured spores settled slower than dark spores. Settling speed of spore clusters agrees with earlier studies. Effective spore discharge and small, slowly settling spores appear particularly important for species in forested habitats. The spore discharge heights in Sphagnum are among the greatest for small, wind-dispersed propagules. The discharge heights and the slow settling of spores affect dispersal distances positively and may help to explain the wide distribution of most boreal Sphagnum species.

  6. Streptococcus mutans: a new Gram-positive paradigm?

    Science.gov (United States)

    Quivey, Robert G.; Koo, Hyun; Abranches, Jacqueline

    2013-01-01

    Despite the enormous contributions of the bacterial paradigms Escherichia coli and Bacillus subtilis to basic and applied research, it is well known that no single organism can be a perfect representative of all other species. However, given that some bacteria are difficult, or virtually impossible, to cultivate in the laboratory, that some are recalcitrant to genetic and molecular manipulation, and that others can be extremely dangerous to manipulate, the use of model organisms will continue to play an important role in the development of basic research. In particular, model organisms are very useful for providing a better understanding of the biology of closely related species. Here, we discuss how the lifestyle, the availability of suitable in vitro and in vivo systems, and a thorough understanding of the genetics, biochemistry and physiology of the dental pathogen Streptococcus mutans have greatly advanced our understanding of important areas in the field of bacteriology such as interspecies biofilms, competence development and stress responses. In this article, we provide an argument that places S. mutans, an organism that evolved in close association with the human host, as a novel Gram-positive model organism. PMID:23393147

  7. Changes of the Quinolones Resistance to Gram-positive Cocci Isolated during the Past 8 Years in the First Bethune Hospital

    Science.gov (United States)

    Xu, Jiancheng; Chen, Qihui; Yao, Hanxin; Zhou, Qi

    This study was to investigate the quinolones resistance to gram-positive cocci isolated in the First Bethune Hospital during the past 8 years. Disk diffusion test was used to study the antimicrobial resistance. The data were analyzed by WHONET 5 software according to Clinical and Laboratory Standards Institute (CLSI). The rates of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococci (MRCNS) were 50.8%∼83.3% and 79.4%∼81.5%during the past 8 years, respectively. In recent 8 years, the quinolones resistance to gram-positive cocci had increased. Monitoring of the quinolones resistance to gram-positive cocci should be strengthened. The change of the antimicrobial resistance should be investigated in order to guide rational drug usage in the clinic and prevent bacterial strain of drug resistance from being transmitted.

  8. Mechanism of action of recombinant acc-royalisin from royal jelly of Asian honeybee against gram-positive bacteria.

    Directory of Open Access Journals (Sweden)

    Lirong Shen

    Full Text Available The antibacterial activity of royalisin, an antimicrobial peptide from the royal jelly produced by honeybees, has been addressed extensively. However, its mechanism of action remains unclear. In this study, a recombinant royalisin, RAcc-royalisin from the royal jelly of Asian honeybee Apis cerana cerana, was expressed by fusing with glutathione S-transferase (GST in Escherichia coli BL21, isolated and purified. The agar dilution assays with inhibition zone showed that RAcc-royalisin, similar to nisin, inhibits the growth of Gram-positive bacteria. The antibacterial activity of RAcc-royalisin was associated with its concentration, and was weakened by heat treatment ranging from 55°C to 85°C for 15 min. Both RAcc-royalisin and nisin exhibited the minimum inhibitory concentrations (MIC of 62.5 µg/ml, 125 µg/ml, and 250 µg/ml against Gram-positive bacterial strains, Bacillus subtilis and Micrococcus flavus and Staphyloccocus aureus in the microplate assay, respectively. However, RAcc-royalisin did not show antimicrobial activity against tested Gram-negative bacterial and fungal strains. The antibacterial activity of RAcc-royalisin agrees well with the decrease in bacterial cell hydrophobicity, the leakage of 260-nm absorbing materials, and the observation by transmission electron microscopy, all indicating that RAcc-royalisin induced the disruption and dysfunction of cell walls and membranes. This is the first report detailing the antibacterial mechanism of royalisin against Gram-positive bacteria, and provides insight into the application of recombinant royalisin in food and pharmaceutical industries as an antimicrobial agent.

  9. High-Resolution Spore Coat Architecture and Assembly of Bacillus Spores

    Energy Technology Data Exchange (ETDEWEB)

    Malkin, A J; Elhadj, S; Plomp, M

    2011-03-14

    Elucidating the molecular architecture of bacterial and cellular surfaces and its structural dynamics is essential to understanding mechanisms of pathogenesis, immune response, physicochemical interactions, environmental resistance, and provide the means for identifying spore formulation and processing attributes. I will discuss the application of in vitro atomic force microscopy (AFM) for studies of high-resolution coat architecture and assembly of several Bacillus spore species. We have demonstrated that bacterial spore coat structures are phylogenetically and growth medium determined. We have proposed that strikingly different species-dependent coat structures of bacterial spore species are a consequence of sporulation media-dependent nucleation and crystallization mechanisms that regulate the assembly of the outer spore coat. Spore coat layers were found to exhibit screw dislocations and two-dimensional nuclei typically observed on inorganic and macromolecular crystals. This presents the first case of non-mineral crystal growth patterns being revealed for a biological organism, which provides an unexpected example of nature exploiting fundamental materials science mechanisms for the morphogenetic control of biological ultrastructures. We have discovered and validated, distinctive formulation-specific high-resolution structural spore coat and dimensional signatures of B. anthracis spores (Sterne strain) grown in different formulation condition. We further demonstrated that measurement of the dimensional characteristics of B. anthracis spores provides formulation classification and sample matching with high sensitivity and specificity. I will present data on the development of an AFM-based immunolabeling technique for the proteomic mapping of macromolecular structures on the B. anthracis surfaces. These studies demonstrate that AFM can probe microbial surface architecture, environmental dynamics and the life cycle of bacterial and cellular systems at near

  10. A Trojan-Horse Strategy Including a Bacterial Suicide Action for the Efficient Use of a Specific Gram-Positive Antibiotic on Gram-Negative Bacteria.

    Science.gov (United States)

    Schalk, Isabelle J

    2018-05-10

    In the alarming context of rising bacterial antibiotic resistance, there is an urgent need to discover new antibiotics or increase and/or enlarge the activity of those currently in use. The need for new antibiotics is even more urgent in the case of Gram-negative bacteria, such as Acinetobacter, Pseudomonas, and Enterobacteria, which have become resistant to many antibiotics and have an outer membrane with very low permeability to drugs. Vectorization of antibiotics using siderophores may be a solution to bypass such a bacterial wall: the drugs use the iron transporters of the outer membrane as gates to enter bacteria in a Trojan-horse strategy. Designing siderophore-antibiotics that can cross outer membranes has become almost routine, but their transport across the inner membrane is still a limiting step, as well as a strategy that allows dissociation of the antibiotic from the siderophore once inside the bacteria. Liu et al. ( J. Med. Chem. 2018 , DOI: 10.1021/acs.jmedchem.8b00218 ) report the synthesis of a siderophore-cephalosporin compound and demonstrate that β-lactams, such as cephalosporins, can serve as β-lactamase-triggered releasable linkers to allow intracellular delivery of Gram-positive antibiotics to Gram-negative bacteria.

  11. Antibacterial activity and interactions of plant essential oil combinations against Gram-positive and Gram-negative bacteria

    Directory of Open Access Journals (Sweden)

    Cristina Anamaria Semeniuc

    2017-04-01

    Full Text Available The aim of this study was to compare the antibacterial effects of several essential oils (EOs alone and in combination against different Gram-positive and Gram-negative bacteria associated with food products. Parsley, lovage, basil, and thyme EOs, as well as their mixtures (1:1, v/v, were tested against Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Salmonella typhimurium. The inhibitory effects ranged from strong (thyme EO against E. coli to no inhibition (parsley EO against P. aeruginosa. Thyme EO exhibited strong (against E. coli, moderate (against S. typhimurium and B. cereus, or mild inhibitory effects (against P. aeruginosa and S. aureus, and basil EO showed mild (against E. coli and B. cereus or no inhibitory effects (against S. typhimurium, P. aeruginosa, and S. aureus. Parsley and lovage EOs revealed no inhibitory effects against all tested strains. Combinations of lovage/thyme and basil/thyme EOs displayed antagonistic effects against all bacteria, parsley/thyme EOs against B. cereus, S. aureus, P. aeruginosa, and E. coli, and lovage/basil EOs against B. cereus and E. coli. Combinations of parsley/lovage and parsley/basil EOs exhibited indifferent effects against all bacteria. The combination of lovage/basil EO showed indifferent effect against S. aureus, P. aeruginosa, and S. typhimurium, and the combination parsley/thyme EO against S. typhimurium. Thyme EO has the highest percentage yield and antibacterial potential from all tested formulations; its combination with parsley, lovage, and basil EOs determines a reduction of its antibacterial activity. Hence, it is recommended to be used alone as the antibacterial agent.

  12. Miniaturized bead-beating device to automate full DNA sample preparation processes for gram-positive bacteria.

    Science.gov (United States)

    Hwang, Kyu-Youn; Kwon, Sung Hong; Jung, Sun-Ok; Lim, Hee-Kyun; Jung, Won-Jong; Park, Chin-Sung; Kim, Joon-Ho; Suh, Kahp-Yang; Huh, Nam

    2011-11-07

    We have developed a miniaturized bead-beating device to automate nucleic acids extraction from Gram-positive bacteria for molecular diagnostics. The microfluidic device was fabricated by sandwiching a monolithic flexible polydimethylsiloxane (PDMS) membrane between two glass wafers (i.e., glass-PDMS-glass), which acted as an actuator for bead collision via its pneumatic vibration without additional lysis equipment. The Gram-positive bacteria, S. aureus and methicillin-resistant S. aureus, were captured on surface-modified glass beads from 1 mL of initial sample solution and in situ lyzed by bead-beating operation. Then, 10 μL or 20 μL of bacterial DNA solution was eluted and amplified successfully by real-time PCR. It was found that liquid volume fraction played a crucial role in determining the cell lysis efficiency in a confined chamber by facilitating membrane deflection and bead motion. The miniaturized bead-beating operation disrupted most of S. aureus within 3 min, which turned out to be as efficient as the conventional benchtop vortexing machine or the enzyme-based lysis technique. The effective cell concentration was significantly enhanced with the reduction of initial sample volume by 50 or 100 times. Combination of such analyte enrichment and in situ bead-beating lysis provided an excellent PCR detection sensitivity amounting to ca. 46 CFU even for the Gram-positive bacteria. The proposed bead-beating microdevice is potentially useful as a nucleic acid extraction method toward a PCR-based sample-to-answer system. This journal is © The Royal Society of Chemistry 2011

  13. Phylogenetic placement of two species known only from resting spores

    DEFF Research Database (Denmark)

    Hajek, Ann E; Gryganskyi, Andrii; Bittner, Tonya

    2016-01-01

    resting spores, Zoophthora independentia, infecting Tipula (Lunatipula) submaculata in New York State, is now described as a new species and Tarichium porteri, described in 1942, which infects Tipula (Triplicitipula) colei in Tennessee, is transferred to the genus Zoophthora. We have shown that use......Molecular methods were used to determine the generic placement of two species of Entomophthorales known only from resting spores. Historically, these species would belong in the form-genus Tarichium, but this classification provides no information about phylogenetic relationships. Using DNA from...... of molecular methods can assist with determination of the phylogenetic relations of specimens within the form-genus Tarichium for an already described species and a new species for which only resting spores are available....

  14. Determination of the irradiation dose for the inhibition (D-10 radiation doses) of some gram negative and gram positive bacteria in peptone saline water

    International Nuclear Information System (INIS)

    Ayhan, H.; Tutluer, H.

    1994-01-01

    Determination of the irradiation dose for the inhibition of some pathogenic bacteria which cause food poisoning and spoilage were aimed. For this purpose, Salmonella typhi, Salmonella typhimurium,Salmonella enteridits,Klebsiella pneumonia, Pseudomonas fluorescence,Proteus vulgaris, Aeromonas hydrophila ,(gram-negative bacteria) and Bacillus cereus, Staphylococcus aureus strain 24,Staphylococcus aureus ATCC 6538 P,Staphylococcus epidermidis strain 115 and Clostridium perfringens A4TTK,(gram-positive bacteria) were used.Sensitivity of above mentioned bacteria to gamma rays (source Cs-137) was examined in saline with 0.1% peptone at different temperatures.Survivor plots (log.10 number of survivors versus dose) were determined by regression analysis of the data.Decimal reduction doses (D values in kGy) were calculated as the slope obtained from the regression analysis

  15. Isolation of highly active monoclonal antibodies against multiresistant gram-positive bacteria.

    Directory of Open Access Journals (Sweden)

    Friederike S Rossmann

    Full Text Available Multiresistant nosocomial pathogens often cause life-threatening infections that are sometimes untreatable with currently available antibiotics. Staphylococci and enterococci are the predominant Gram-positive species associated with hospital-acquired infections. These infections often lead to extended hospital stay and excess mortality. In this study, a panel of fully human monoclonal antibodies was isolated from a healthy individual by selection of B-cells producing antibodies with high opsonic killing against E. faecalis 12030. Variable domains (VH and VL of these immunoglobulin genes were amplified by PCR and cloned into an eukaryotic expression vector containing the constant domains of a human IgG1 molecule and the human lambda constant domain. These constructs were transfected into CHO cells and culture supernatants were collected and tested by opsonophagocytic assay against E. faecalis and S. aureus strains (including MRSA. At concentrations of 600 pg/ml, opsonic killing was between 40% and 70% against all strains tested. Monoclonal antibodies were also evaluated in a mouse sepsis model (using S. aureus LAC and E. faecium, a mouse peritonitis model (using S. aureus Newman and LAC and a rat endocarditis model (using E. faecalis 12030 and were shown to provide protection in all models at a concentration of 4 μg/kg per animal. Here we present a method to produce fully human IgG1 monoclonal antibodies that are opsonic in vitro and protective in vivo against several multiresistant Gram-positive bacteria. The monoclonal antibodies presented in this study are significantly more effective compared to another monoclonal antibody currently in clinical trials.

  16. Spore-to-spore agar culture of the myxomycete Physarum globuliferum.

    Science.gov (United States)

    Liu, Pu; Wang, Qi; Li, Yu

    2010-02-01

    The ontogeny of the myxomycete Physarum globuliferum was observed on corn meal agar and hanging drop cultures without adding sterile oat flakes, bacteria or other microorganisms. Its complete life cycle including spore germination, myxamoebae, swarm cells, plasmodial development, and maturity of fructifications was demonstrated. Details of spore-to-spore development are described and illustrated.

  17. Thermal Inactivation of Bacillus anthracis Spores Using Rapid Resistive Heating

    Science.gov (United States)

    2016-03-24

    agents. There is motivation for using thermal decontamination of B.a. spores for agent defeat scenarios. Spore-forming microorganisms are much...the top soil on Gruinard Island for over 40 years after the British detonated experimental anthrax bombs on the island during World War II (U.S

  18. Flow cytometric evaluation of physico-chemical impact on Gram-positive and Gram-negative bacteria

    Science.gov (United States)

    Fröhling, Antje; Schlüter, Oliver

    2015-01-01

    Since heat sensitivity of fruits and vegetables limits the application of thermal inactivation processes, new emerging inactivation technologies have to be established to fulfill the requirements of food safety without affecting the produce quality. The efficiency of inactivation treatments has to be ensured and monitored. Monitoring of inactivation effects is commonly performed using traditional cultivation methods which have the disadvantage of the time span needed to obtain results. The aim of this study was to compare the inactivation effects of peracetic acid (PAA), ozonated water (O3), and cold atmospheric pressure plasma (CAPP) on Gram-positive and Gram-negative bacteria using flow cytometric methods. E. coli cells were completely depolarized after treatment (15 s) with 0.25% PAA at 10°C, and after treatment (10 s) with 3.8 mg l−1 O3 at 12°C. The membrane potential of CAPP treated cells remained almost constant at an operating power of 20 W over a time period of 3 min, and subsequently decreased within 30 s of further treatment. Complete membrane permeabilization was observed after 10 s O3 treatment, but treatment with PAA and CAPP did not completely permeabilize the cells within 2 and 4 min, respectively. Similar results were obtained for esterase activity. O3 inactivates cellular esterase but esterase activity was detected after 4 min CAPP treatment and 2 min PAA treatment. L. innocua cells and P. carotovorum cells were also permeabilized instantaneously by O3 treatment at concentrations of 3.8 ± 1 mg l−1. However, higher membrane permeabilization of L. innocua and P. carotovorum than of E. coli was observed at CAPP treatment of 20 W. The degree of bacterial damage due to the inactivation processes is highly dependent on treatment parameters as well as on treated bacteria. Important information regarding the inactivation mechanisms can be obtained by flow cytometric measurements and this enables the definition of critical process parameters. PMID

  19. Flow cytometric evaluation of physico-chemical impact on Gram-positive and Gram-negative bacteria

    Directory of Open Access Journals (Sweden)

    Antje eFröhling

    2015-09-01

    Full Text Available Since heat sensitivity of fruits and vegetables limits the application of thermal inactivation processes, new emerging inactivation technologies have to be established to fulfil the requirements of food safety without affecting the produce quality. The efficiency of inactivation treatments has to be ensured and monitored. Monitoring of inactivation effects is commonly performed using traditional cultivation methods which have the disadvantage of the time span needed to obtain results.The aim of this study was to compare the inactivation effects of peracetic acid (PAA, ozonated water (O3 and cold atmospheric pressure plasma (CAPP on Gram-positive and Gram-negative bacteria using flow cytometric methods. E. coli cells were completely depolarized after treatment (15 s with 0.25 % PAA at 10 °C, and after treatment (10 s with 3.8 mg l-1 O3 at 12°C. The membrane potential of CAPP treated cells remained almost constant at an operating power of 20 W over a time period of 3 min, and subsequently decreased within 30 s of further treatment. Complete membrane permeabilization was observed after 10 s O3 treatment, but treatment with PAA and CAPP did not completely permeabilize the cells within 2 min and 4 min, respectively. Similar results were obtained for esterase activity. O3 inactivates cellular esterase but esterase activity was detected after 4 min CAPP treatment and 2 min PAA treatment. L. innocua cells and P. carotovorum cells were also permeabilized instantaneously by O3 treatment at concentrations of 3.8 ± 1 mg l-1. However, higher membrane permeabilization of L. innocua and P. carotovorum than of E. coli was observed at CAPP treatment of 20 W. The degree of bacterial damage due to the inactivation processes is highly dependent on treatment parameters as well as on treated bacteria. Important information regarding the inactivation mechanisms can be obtained by flow cytometric measurements and this enables the definition of critical process

  20. With respect to coefficient of linear thermal expansion, bacterial vegetative cells and spores resemble plastics and metals, respectively.

    Science.gov (United States)

    Nakanishi, Koichi; Kogure, Akinori; Fujii, Takenao; Kokawa, Ryohei; Deuchi, Keiji; Kuwana, Ritsuko; Takamatsu, Hiromu

    2013-10-09

    If a fixed stress is applied to the three-dimensional z-axis of a solid material, followed by heating, the amount of thermal expansion increases according to a fixed coefficient of thermal expansion. When expansion is plotted against temperature, the transition temperature at which the physical properties of the material change is at the apex of the curve. The composition of a microbial cell depends on the species and condition of the cell; consequently, the rate of thermal expansion and the transition temperature also depend on the species and condition of the cell. We have developed a method for measuring the coefficient of thermal expansion and the transition temperature of cells using a nano thermal analysis system in order to study the physical nature of the cells. The tendency was seen that among vegetative cells, the Gram-negative Escherichia coli and Pseudomonas aeruginosa have higher coefficients of linear expansion and lower transition temperatures than the Gram-positive Staphylococcus aureus and Bacillus subtilis. On the other hand, spores, which have low water content, overall showed lower coefficients of linear expansion and higher transition temperatures than vegetative cells. Comparing these trends to non-microbial materials, vegetative cells showed phenomenon similar to plastics and spores showed behaviour similar to metals with regards to the coefficient of liner thermal expansion. We show that vegetative cells occur phenomenon of similar to plastics and spores to metals with regard to the coefficient of liner thermal expansion. Cells may be characterized by the coefficient of linear expansion as a physical index; the coefficient of linear expansion may also characterize cells structurally since it relates to volumetric changes, surface area changes, the degree of expansion of water contained within the cell, and the intensity of the internal stress on the cellular membrane. The coefficient of linear expansion holds promise as a new index for

  1. Evaluation of the LightCycler Staphylococcus M GRADE kits on positive blood cultures that contained gram-positive cocci in clusters.

    Science.gov (United States)

    Shrestha, Nabin K; Tuohy, Marion J; Padmanabhan, Ravindran A; Hall, Gerri S; Procop, Gary W

    2005-12-01

    We evaluated the Roche LightCycler Staphylococcus M(GRADE) kits to differentiate between Staphylococcus aureus and coagulase-negative staphylococci in blood cultures growing clusters of gram-positive cocci. Testing 100 bottles (36 containing S. aureus), the assay was 100% sensitive and 98.44% specific for S. aureus and 100% sensitive and specific for coagulase-negative staphylococci.

  2. Distinction of broken cellular wall Ganoderma lucidum spores and G. lucidum spores using FTIR microspectroscopy

    Science.gov (United States)

    Chen, Xianliang; Liu, Xingcun; Sheng, Daping; Huang, Dake; Li, Weizu; Wang, Xin

    2012-11-01

    In this paper, FTIR microspectroscopy was used to identify broken cellular wall Ganoderma lucidum spores and G. lucidum spores. For IR spectra, broken cellular wall G. lucidum spores and G. lucidum spores were mainly different in the regions of 3000-2800, 1660-1600, 1400-1200 and 1100-1000 cm-1. For curve fitting, the results showed the differences in the protein secondary structures and the polysaccharide structures/content between broken cellular wall G. lucidum spores and G. lucidum spores. Moreover, the value of A1078/A1741 might be a potentially useful factor to distinguish broken cellular wall G. lucidum spores from G. lucidum spores. Additionally, FTIR microspectroscopy could identify broken cellular wall G. lucidum spores and G. lucidum spores accurately when it was combined with hierarchical cluster analysis. The result suggests FTIR microspectroscopy is very simple and efficient for distinction of broken cellular wall G. lucidum spores and G. lucidum spores. The result also indicates FTIR microspectroscopy may be useful for TCM identification.

  3. Generation of multiple cell types in Bacillus subtilis.

    Science.gov (United States)

    Lopez, Daniel; Vlamakis, Hera; Kolter, Roberto

    2009-01-01

    Bacillus subtilis is a Gram-positive bacterium that is well known for its ability to differentiate into metabolically inactive spores that are highly resistant to environmental stresses. In fact, populations of genetically identical B. subtilis comprise numerous distinct cell types. In addition to spores, cells can become genetically competent, motile, produce extracellular matrix or degradative enzymes, or secrete toxins that allow them to cannibalize their neighbors. Many of the cell fates listed above appear to be mutually exclusive. In this review, we discuss how individual cells within a population control their gene expression to ensure that proper regulation of differentiation occurs. These different cell fates are regulated by an intricate network that relies primarily on the activity of three major transcriptional regulators: Spo0A, DegU, and ComK. While individual cells must choose distinct cell fates, the population as a whole exhibits a spectrum of phenotypes whose diversity may increase fitness.

  4. Clostridium difficile infection: molecular pathogenesis and novel therapeutics

    Science.gov (United States)

    Rineh, Ardeshir; Kelso, Michael J; Vatansever, Fatma; Tegos, George P; Hamblin, Michael R

    2015-01-01

    The Gram-positive anaerobic bacterium Clostridium difficile produces toxins A and B, which can cause a spectrum of diseases from pseudomembranous colitis to C. difficile-associated diarrhea. A limited number of C. difficile strains also produce a binary toxin that exhibits ADP ribosyltransferase activity. Here, the structure and the mechanism of action of these toxins as well as their role in disease are reviewed. Nosocomial C. difficile infection is often contracted in hospital when patients treated with antibiotics suffer a disturbance in normal gut microflora. C. difficile spores can persist on dry, inanimate surface for months. Metronidazole and oral vancomycin are clinically used for treatment of C. difficile infection but clinical failure and concern about promotion of resistance are motivating the search for novel non-antibiotic therapeutics. Methods for controlling both toxins and spores, replacing gut microflora by probiotics or fecal transplant, and killing bacteria in the anaerobic gut by photodynamic therapy are discussed. PMID:24410618

  5. Noncontiguous finished genome sequence and description of Planococcus massiliensis sp. nov., a moderately halophilic bacterium isolated from the human gut

    Directory of Open Access Journals (Sweden)

    E.H. Seck

    2016-03-01

    Full Text Available We propose the main phenotypic characteristics and the complete genome sequence and annotation of Planococcus massiliensis strain ES2T (= CSUR P1103 = DSM 28915, the type strain of P. massiliensis sp. nov., isolated from a faeces sample collected from a healthy Senegalese man. It is an aerobic, Gram-positive, moderately halophilic, motile and rod-shaped bacterium. The 3 357 017 bp long genome exhibits a G+C content of 46.0% and contains 3357 protein-coding genes and 48 RNA genes.

  6. Limitations in the use of Drosophila melanogaster as a model host for gram-positive bacterial infection

    DEFF Research Database (Denmark)

    Jensen, Rikke Lind; Pedersen, K.S.; Loeschcke, V

    2007-01-01

    resistance respectively, were subjected to infection by L. monocytogenes, S. aureus and E. coli. Mortality rates were comparable with that of the Oregon R strain. Conclusions: Use of the injection method shows the limitation of D. melanogaster as a model host for gram-positive bacteria as opportunistic......Aims: To examine sensitivities of various Drosophila melanogaster strains towards human pathogenic and nonpathogenic gram-positive bacteria. Methods and Results: The D. melanogaster Oregon R strain was infected by injecting the thorax with a needle containing Escherichia coli (negative control...... with the negative control. Infection with L. innocua, B. subtilis or C. maltaromaticum also resulted in a high fly mortality, whereas Lact. plantarum and P. acidilactici resulted in a slightly increased mortality. Four additional D. melanogaster lines, three of which had been selected for heat, cold and desiccation...

  7. Influence of selected variables on transport of plutonium to spores of Aspergillus niger

    International Nuclear Information System (INIS)

    Au, F.H.F.; Beckert, W.F.

    1975-01-01

    Studies were carried out on the influences of different chemical forms and concentrations of Pu at two hydrogen ion concentrations of the culture medium on uptake and transport of 238 Pu to the spores of Aspergillus niger. Results indicated that Pu, when added to the culture medium as dioxide microspheres, nitrate, or citrate complex, was transported to the spores, and that an almost linear relationship existed between transport and concentration. Raising the pH of the culture medium from 2.5 to 5.5 generally increased transport of Pu to spores for all three chemical forms. At Pu concentrations of 224 pCi/g in the culture media, and for both pH 2.5 and 5.5, transport of Pu to spores was approximately three times as high from the nitrate or citrate form as from the dioxide microspheres. (auth)

  8. Distinction of broken cellular wall Ganoderma lucidum spores and G. lucidum spores using FTIR microspectroscopy.

    Science.gov (United States)

    Chen, Xianliang; Liu, Xingcun; Sheng, Daping; Huang, Dake; Li, Weizu; Wang, Xin

    2012-11-01

    In this paper, FTIR microspectroscopy was used to identify broken cellular wall Ganoderma lucidum spores and G. lucidum spores. For IR spectra, broken cellular wall G. lucidum spores and G. lucidum spores were mainly different in the regions of 3000-2800, 1660-1600, 1400-1200 and 1100-1000 cm(-1). For curve fitting, the results showed the differences in the protein secondary structures and the polysaccharide structures/content between broken cellular wall G. lucidum spores and G. lucidum spores. Moreover, the value of A1078/A1741 might be a potentially useful factor to distinguish broken cellular wall G. lucidum spores from G. lucidum spores. Additionally, FTIR microspectroscopy could identify broken cellular wall G. lucidum spores and G. lucidum spores accurately when it was combined with hierarchical cluster analysis. The result suggests FTIR microspectroscopy is very simple and efficient for distinction of broken cellular wall G. lucidum spores and G. lucidum spores. The result also indicates FTIR microspectroscopy may be useful for TCM identification. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Arbuscular mycorrhizal fungi spore propagation using single spore as starter inoculum and a plant host.

    Science.gov (United States)

    Selvakumar, G; Shagol, C C; Kang, Y; Chung, B N; Han, S G; Sa, T M

    2018-06-01

    The propagation of pure cultures of arbuscular mycorrhizal fungal (AMF) is an essential requirement for their large-scale agricultural application and commercialization as biofertilizers. The present study aimed to propagate AMF using the single-spore inoculation technique and compare their propagation ability with the known reference spores. Arbuscular mycorrhizal fungal spores were collected from salt-affected Saemangeum reclaimed soil in South Korea. The technique involved inoculation of sorghum-sudangrass (Sorghum bicolor L.) seedlings with single, healthy spores on filter paper followed by the transfer of successfully colonized seedlings to 1-kg capacity pots containing sterilized soil. After the first plant cycle, the contents were transferred to 2·5-kg capacity pots containing sterilized soil. Among the 150 inoculated seedlings, only 27 seedlings were colonized by AMF spores. After 240 days, among the 27 seedlings, five inoculants resulted in the production of over 500 spores. The 18S rDNA sequencing of spores revealed that the spores produced through single-spore inoculation method belonged to Gigaspora margarita, Claroideoglomus lamellosum and Funneliformis mosseae. Furthermore, indigenous spore F. mosseae M-1 reported a higher spore count than the reference spores. The AMF spores produced using the single-spore inoculation technique may serve as potential bio-inoculants with an advantage of being more readily adopted by farmers due to the lack of requirement of a skilled technique in spore propagation. The results of the current study describe the feasible and cost-effective method to mass produce AMF spores for large-scale application. The AMF spores obtained from this method can effectively colonize plant roots and may be easily introduced to the new environment. © 2018 The Society for Applied Microbiology.

  10. Characterization of an Hfq dependent antisense sRNA in the Gram-positive human pathogen Listeria monocytogenes

    DEFF Research Database (Denmark)

    Nielsen, Jesper Sejrup; Lei Kristensen, Lisbeth; Hanghøj Chrisitansen, Mie

    between sRNA and target mRNA rely on the RNA chaperone Hfq. Hfq is a ubiquitous protein found in almost all genres of bacterial life. However, so far its role as an RNA chaperone has only been described in Gram-negative species such as Escherichia coli and Salmonella (Vogel, J. 2009). We previously...... identified several Hfq-binding sRNAs in the Gram-positive human pathogen L. monocytogenes (Christiansen et al 2006). Through bioinformatics, we have identified a number of candidate targets for one of these sRNAs (LhrA). Here, we present the characterization of one of these targets. Our results suggest...

  11. Characterization of the Lactobacillus isolated from different curd ...

    African Journals Online (AJOL)

    Lactic acid bacteria are commonly found in the fermented dairy products. Lactobacillus is a genus of lactic acid bacteria and described as heterogeneous group of regular, non-spore forming, gram-positive, rod shaped, non-motile bacteria and absence of catalase enzyme. The aim of this study was to isolate Lactobacillus ...

  12. New and improved? A review of novel antibiotics for Gram-positive bacteria.

    Science.gov (United States)

    Abbas, M; Paul, M; Huttner, A

    2017-10-01

    The number of antibiotics in the pipeline targeting Gram-positive pathogens has increased in recent years. This narrative review aims to provide a summary of existing evidence on efficacy, microbiological spectrum and safety of novel systemic antibiotics that have either recently been licensed or completed phase III trials, and possess activity predominantly against Gram-positive organisms. A review of the published literature via the MEDLINE database was performed. In addition, ongoing trials were identified through a search of the clinical trial registration platform clinicaltrials.gov, and when necessary, pharmaceutical companies responsible for the development of the drug were contacted for further information. Data on development, microbiological spectrum, pharmacokinetic/pharmacodynamic properties, clinical efficacy, safety and cost are presented for the new cephalosporins ceftaroline and ceftobiprole; the lipoglycopeptides dalbavancin, oritavancin and telavancin; the fluoroquinolones delafloxacin, nemonoxacin and zabofloxacin; the dihydrofolate-reductase inhibitor iclaprim; the pleuromutilin lefamulin; and the tetracycline omadacycline. Although promising, these new antibiotics have so far been tested in non-severe infections whose treatment is generally uncomplicated and whose aetiologies were not predominantly multidrug-resistant pathogens. None of the new antibiotics have shown superiority to standard care, and none have been investigated for patient-relevant outcomes. Safety and pharmacokinetic data continue to be lacking. How these new drugs are to be integrated into the current armamentarium remains to be established. Copyright © 2017 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  13. Effect of sporulation medium on wet-heat resistance and structure of Alicyclobacillus acidoterrestris DSM 3922-type strain spores and modeling of the inactivation kinetics in apple juice.

    Science.gov (United States)

    Molva, Celenk; Baysal, Ayse Handan

    2014-10-17

    Alicyclobacillus acidoterrestris is a spoilage bacterium in fruit juices leading to high economic losses. The present study evaluated the effect of sporulation medium on the thermal inactivation kinetics of A. acidoterrestris DSM 3922 spores in apple juice (pH3.82±0.01; 11.3±0.1 °Brix). Bacillus acidocaldarius agar (BAA), Bacillus acidoterrestris agar (BATA), malt extract agar (MEA), potato dextrose agar (PDA) and B. acidoterrestris broth (BATB) were used for sporulation. Inactivation kinetic parameters at 85, 87.5 and 90°C were obtained using the log-linear model. The decimal reduction times at 85°C (D85°C) were 41.7, 57.6, 76.8, 76.8 and 67.2min; D87.5°C-values were 22.4, 26.7, 32.9, 31.5, and 32.9min; and D90°C-values were 11.6, 9.9, 14.7, 11.9 and 14.1min for spores produced on PDA, MEA, BATA, BAA and BATB, respectively. The estimated z-values were 9.05, 6.60, 6.96, 6.15, and 7.46, respectively. The present study suggests that the sporulation medium affects the wet-heat resistance of A. acidoterrestris DSM 3922 spores. Also, the dipicolinic acid content (DPA) was found highest in heat resistant spores formed on mineral containing media. After wet-heat treatment, loss of internal volume due to the release of DPA from spore core was observed by scanning electron microscopy. Since, there is no standardized media for the sporulation of A. acidoterrestris, the results obtained from this study might be useful to determine and compare the thermal resistance characteristics of A. acidoterrestris spores in fruit juices. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Engineering a predatory bacterium as a proficient killer agent for intracellular bio-products recovery

    DEFF Research Database (Denmark)

    Martinez, Virginia; Herencias, Cristina; Jurkevitch, Edouard

    2016-01-01

    This work examines the potential of the predatory bacterium Bdellovibrio bacteriovorus HD100, an obligate predator of other Gram-negative bacteria, as an external cell-lytic agent for recovering valuable intracellular bio-products produced by prey cultures. The bio-product targets to be recovered......% of that accumulated by the prey bacteria, even at high biomass concentrations. This innovative downstream process highlights how B. bacteriovorus can be used as a novel, biological lytic agent for the inexpensive, industrial scale recovery of intracellular products from different Gram-negative prey cultures....

  15. Biodegradation of crude oil in different types of marine sediment

    International Nuclear Information System (INIS)

    Hii, Y.S.; Law, A.T.

    1999-01-01

    An active oil-oxidizing bacterium, named Nap C was isolated from the sediment sample of Port Dickson coastal area for this study. Nap C is a gram negative, rod shape marine bacterium. It forms spore when the condition is not favorable. Three different types of treated marine sediment; sand, silt and clay were used in this study. The degradation of Malaysian Tapis A crude oil in the different types of marine sediment were assessed. Silt type of marine sediment was found to sustain highest biodegradation compared to clay type and sand type. 8.6.67% of the Malaysian Tapis A crude oil was degraded in silt type of marine sediment within 10 days of incubation. Where as there were only 60% and 73% of the Malaysian Tapis A crude oil was degraded in sand and clay type of marine sediment respectively. Microbial biomass estimation in the sediment was estimated by indirect phospholipid enumeration technique. (author)

  16. Fertile organs and in situ spores of a new dipteridaceous fern Hausmannia sinensis from the Jurassic of northern China.

    Science.gov (United States)

    Wang, Yongdong; Zhang, Hong

    2010-01-22

    As a representative fossil member of the dipteridaceous fern, genus Hausmannia was reported worldwide from the Mesozoic strata; however, little is known about the fertile structures, including sporangia and in situ spores, of this genus. In this study, a new species Hausmannia sinensis was identified from the Middle Jurassic of Nei Mongol (Inner Mongolia), northern China. The specimens are compressions and are well preserved with details of sporangia and in situ spores. The leaf laminae are broadly fan-shaped, with an almost entire margin. Primary and lateral veins dichotomously branch to form square or polygonal meshes. Each ultimate mesh bears one to two circular sori of 0.4 mm in diameter. Sori are exindusiate; each sorus contains three to six round to ovoid sporangia. The annulus is developed and oblique, with stomial region present in proximal position. Spores are trilete, circular to oval in shape. Both proximal and distal surfaces are covered with baculate to subverrucate sculptures. Spores range from 20 to 30 microm in diameter (average 28 microm), and are comparable to the dispersed genera Baculatisporites Thomas and Pflug and Apiculatisporis Potonié and Kremp. Hausmannia sinensis represents the first compression species of genus Hausmannia form Eurasia, which shows the combination of well-preserved sori, sporangia, annuli and in situ spore characters, and is therefore helpful for further understanding the diversity and evolution of the Dipteridaceae fern lineage through time.

  17. In vitro ciprofloxacin resistance patterns of gram positive bacteria isolated from clinical specimens in a teaching hospital in Saudi Arabia

    International Nuclear Information System (INIS)

    Akhtar, N.; Alzahrani, A.; Obeid, O.El-Treify; Dassal, D.

    2009-01-01

    Over the last few decades the ever-increasing level of bacterial resistance to antimicrobials has been a cause of worldwide concern. Fluoroquinolones, particularly ciprofloxacin has been used indiscriminately for both gram-positive and gram-negative bacterial infections. The increased use of ciprofloxacin has led to a progressive loss of bacterial susceptibility to this antibiotic. Therefore it is necessary to have update knowledge of resistance pattern of bacteria to this antibiotic so that alternate appropriate antibiotics can be used for ciprofloxacin-resistant bacterial infections. Objective: To evaluate the trends of ciprofloxacin resistance pattern in commonly isolated gram positive bacteria over time in a Saudi Arabian teaching hospital. Methods: A retrospective analysis was carried out for ciprofloxacin susceptibility patterns of 5534 isolates of gram-positive bacteria isolated from clinical specimens submitted to microbiology laboratories at King Fahd Hospital of the University (KFHU), Al-Khobar, Saudi Arabia during the period from January 2002 to August 2005. Results: Increase in ciprofloxacin resistance rates with some fluctuations, among these isolates, were observed. For Staphylococcus aureus, it varied from 4.62, 1.83, 7.01 and 3.98%, methicillin resistant Staphylococcus aureus (MRSA) 97.92, 97.75, 87.01 and 88.26%, Streptococcus pyogenes 5.35, 4.47, 14.44 and 3.53% during the years 2002, 2003, 2004 and 2005 respectively. Cirprofloxacin resistance during the years 2002, 2004 and 2005 for other isolates was as follows: Streptococcus pneumoniae, 30.23, 23.02 and 26.47%; enterococcus group D, 43.05, 20.68 and 57.03% and non-enterococcus group D, 62.96, 76.92 and 87.50% respectively. Conclusion: Ciprofloxacin resistance in gram positive bacterial clinical isolates particularly Staphylococcus aureus, methicillin resistant Staphylococcus aureus (MRSA) enterococcus group D, and non-enterococcus group D, has greatly increased and ciprofloxacin no more remains

  18. Gram-negative diabetic foot osteomyelitis: risk factors and clinical presentation.

    Science.gov (United States)

    Aragón-Sánchez, Javier; Lipsky, Benjamin A; Lázaro-Martínez, Jose L

    2013-03-01

    Osteomyelitis frequently complicates infections in the feet of patients with diabetes. Gram-positive cocci, especially Staphylococcus aureus, are the most commonly isolated pathogens, but gram-negative bacteria also cause some cases of diabetic foot osteomyelitis (DFO). These gram-negatives require different antibiotic regimens than those commonly directed at gram-positives. There are, however, few data on factors related to their presence and how they influence the clinical picture. We conducted a retrospective study to determine the variables associated with the isolation of gram-negative bacteria from bone samples in cases of DFO and the clinical presentation of these infections. Among 341 cases of DFO, 150 had a gram-negative isolate (alone or combined with a gram-positive isolate) comprising 44.0% of all patients and 50.8% of those with a positive bone culture. Compared with gram-positive infections, wounds with gram-negative organisms more often had a fetid odor, necrotic tissue, signs of soft tissue infection accompanying osteomyelitis, and clinically severe infection. By multivariate analysis, the predictive variables related to an increased likelihood of isolating gram-negatives from bone samples were glycated hemoglobin gram-negatives had a statistically significantly higher prevalence of leukocytosis and higher white blood cell counts than those without gram-negatives. In conclusion, gram-negative organisms were isolated in nearly half of our cases of DFO and were associated with more severe infections, higher white blood cell counts, lower glycated hemoglobin levels, and wounds of traumatic etiology.

  19. Survey on Heterotrophic Bacterial Contamination in Bottled Mineral Water by Culture Method

    Directory of Open Access Journals (Sweden)

    Essmaeel Ghorbanalinezhad

    2014-12-01

    Full Text Available Background and Aim: This project focuses on the level of heterotrophic baceria in bottled mineral water which could be a health concern for the elderly, infants, pregnant women and immuno-compromised patients. Materials and Methods: Different brands of bottled water samples were selected randomly and evaluated for their bacteriological quality, using different specific culture media and biochemical tests. Water samples were analyzed within 24 hours of their purchase/collection. Samples were filtered with 0.45 micron and filters were plated in different media. Then media were incubated at 37˚C for 24-48 hours. Results: Morphological study and biochemical tests revealed a number of bacteria in different   brands of  bottled water. Heterotrophic bacteria(Gram positive cocci, Spore forming gram positive bacilli, non spore forming gram positive bacilli, gram negative bacilli, and gram negative coccobacilli; Pseudomonas and Stenotrophomonas counted in 70% of bottled water samples. There were no cases of fecal contamination or the presence of E.coli. Conclusions: Bottled water is not sterile and contains trace amounts of bacteria naturally present or introduced during processing. Testing drinking water for all possible pathogens is complex, time-consuming, and expensive. If only total coliform bacteria are detected in drinking water, the source is probably environmental. Since the significance of non-pathogenic heterotrophic bacteria in relation to health and diseases is not understood, there is an urgent need to establish a maximum limit for the heterotrophic count in the bottled mineral water. Growth conditions play a critical role in the recovery of heterotrophic bacteria in bottled drinking water.

  20. Emended description of Pasteuria nishizawae.

    Science.gov (United States)

    Noel, Gregory R; Atibalentja, N; Domier, Leslie L

    2005-07-01

    The description of the Gram-positive, obligately parasitic, mycelial and endospore-forming bacterium, Pasteuria nishizawae, is emended to include additional observations on the life cycle, host specificity and endospore morphology. The nucleotide sequence of the 16S rRNA gene is also provided.

  1. The effects of meteorological factors on airborne fungal spore concentration in two areas differing in urbanisation level

    Science.gov (United States)

    Oliveira, M.; Ribeiro, H.; Delgado, J. L.; Abreu, I.

    2009-01-01

    Although fungal spores are an ever-present component of the atmosphere throughout the year, their concentration oscillates widely. This work aims to establish correlations between fungal spore concentrations in Porto and Amares and meteorological data. The seasonal distribution of fungal spores was studied continuously (2005-2007) using volumetric spore traps. To determine the effect of meteorological factors (temperature, relative humidity and rainfall) on spore concentration, the Spearman rank correlation test was used. In both locations, the most abundant fungal spores were Cladosporium, Agaricus, Agrocybe, Alternaria and Aspergillus/Penicillium, the highest concentrations being found during summer and autumn. In the present study, with the exception of Coprinus and Pleospora, spore concentrations were higher in the rural area than in the urban location. Among the selected spore types, spring-autumn spores ( Coprinus, Didymella, Leptosphaeria and Pleospora) exhibited negative correlations with temperature and positive correlations both with relative humidity and rainfall level. On the contrary, late spring-early summer (Smuts) and summer spores ( Alternaria, Cladosporium, Epicoccum, Ganoderma, Stemphylium and Ustilago) exhibited positive correlations with temperature and negative correlations both with relative humidity and rainfall level. Rust, a frequent spore type during summer, had a positive correlation with temperature. Aspergillus/Penicillium, showed no correlation with the meteorological factors analysed. This knowledge can be useful for agriculture, allowing more efficient and reliable application of pesticides, and for human health, by improving the diagnosis and treatment of respiratory allergic disease.

  2. Brazilian experience in EU-CORE: daptomycin registry and treatment of serious Gram-positive infections

    Directory of Open Access Journals (Sweden)

    Artur Timerman

    Full Text Available OBJECTIVES: To collect data about non-controlled prescribing use of daptomycin and its impact among Brazilian patients with serious Gram positive bacterial infection, as well as the efficacy and safety outcomes. MATERIALS AND METHODS: This is a multi-center, retrospective, non-interventional registry (August 01, 2009 to June 30, 2011 to collect data on 120 patients (44 patients in the first year and 76 patients in the second year who had received at least one dose of commercial daptomycin in Brazil for the treatment of serious Gram-positive bacterial infection. RESULTS: Right-sided endocarditis (15.8%, complicated skin and soft tissue infections (cSSTIwound (15.0% and bacteremia-catheter-related (14.2% were the most frequent primary infections; lung (21.7% was the most common site for infection. Daptomycin was used empirically in 76 (63.3% patients, and methicillin-resistant Staphylococcus aureus (MRSA was the most common suspected pathogen (86.1%. 82.5% of the cultures were obtained prior to or shortly after initiation of daptomycin therapy. Staphylococcus spp. - coagulase negative, MRSA, and methicillin-susceptible S. aureus were the most frequently identified pathogens (23.8%, 23.8% and 12.5%, respectively. The most common daptomycin dose administered for bacteremia and cSSTI was 6 mg/kg (30.6% and 4 mg/kg (51.7%, respectively. The median duration of inpatient daptomycin therapy was 14 days. Most patients (57.1% did not receive daptomycin while in intensive care unit. Carbapenem (22.5% was the most commonly used antibiotic concomitantly. The patients showed clinical improvement after two days (median following the start of daptomycin therapy. The clinical success rate was 80.8% and the overall rate of treatment failure was 10.8%. The main reasons for daptomycin discontinuation were successful end of therapy (75.8%, switched therapy (11.7%, and treatment failure (4.2%. Daptomycin demonstrated a favorable safety and tolerability profile

  3. Identification of multidrug-resistant bacteria and Bacillus cereus from ...

    African Journals Online (AJOL)

    However, B. cereus was isolated from the hands of three. HCWs. Table 1 shows species of bacteria isolated from. HCWs and ES in Elkhomes hospital. B. cereus is a Gram-positive spore-forming facultative- anaerobic rod-shaped organism that can be found in different types of soils and widely distributed in the environment.

  4. Wenzhouxiangella sediminis sp. nov. isolated from coastal sediment

    Science.gov (United States)

    A novel Gram-stain-negative, non-spore-forming, no flagellum, facultatively anaerobic, oxidase-negative, catalase- positive, rod-shaped strain, designated XDB06**T, was isolated from coastal sediment of Xiaoshi Island, Weihai, China. Optimal growth occurred at 37 °C, pH 7.5 and with 4.0% (w/v) NaCl....

  5. Laboratory Investigations on the Survival of Bacillus subtilis Spores in Deliquescent Salt Mars Analog Environments

    Science.gov (United States)

    Nuding, Danielle L.; Gough, Raina V.; Venkateswaran, Kasthuri J.; Spry, James A.; Tolbert, Margaret A.

    2017-10-01

    Observed features such as recurring slope lineae suggest that liquid water may exist on the surface and near-subsurface of Mars today. The presence of this liquid water, likely in the form of a brine, has important implications for the present-day water cycle, habitability, and planetary protection policies. It is possible that this water is formed, at least partially, by deliquescence of salts, a process during which hygroscopic salts absorb water vapor from the atmosphere and form a saturated liquid brine. We performed laboratory experiments to examine the ability of Bacillus subtilis (B-168) spores, alone or mixed with calcium perchlorate salt (Ca(ClO4)2), to form liquid water via deliquescence under Mars-relevant conditions. Spore survival after exposure to these conditions was examined. An environmental chamber was used to expose the samples to temperature and relative humidity (RH) values similar to those found on Mars, and Raman microscopy was used to identify the phases of water and salt that were present and to confirm the presence of spores. We found that B-168 spores did not condense any detectable water vapor on their own during the diurnal cycle, even at 100% RH. However, when spores were mixed with perchlorate salt, the entire sample deliquesced at low RH values, immersing the spores in a brine solution during the majority of the simulated martian temperature and humidity cycle. After exposure to the simulated diurnal cycles and, in some cases, perchlorate brine, the impact of each environmental scenario on spore survival was estimated by standard plate assay. We found that, if there are deliquescent salts in contact with spores, there is a mechanism for the spores to acquire liquid water starting with only atmospheric water vapor as the H2O source. Also, neither crystalline nor liquid Ca(ClO4)2 is sporicidal despite the low water activity.

  6. Veillonella, Firmicutes: Microbes disguised as Gram negatives

    DEFF Research Database (Denmark)

    Vesth, Tammi Camilla; Ozen, Asli; Andersen, Sandra Christine

    2013-01-01

    Negativicutes, including the genus Veillonella, stain Gram negative. Veillonella are among the most abundant organisms of the oral and intestinal microflora of animals and humans, in spite of being strict anaerobes. In this work, the genomes of 24 Negativicutes, including eight Veillonella spp., are compared......, with the exception of a shared LPS biosynthesis pathway. The clade within the class Negativicutes to which the genus Veillonella belongs exhibits unique properties, most of which are in common with Gram-positives and some with Gram negatives. They are only distantly related to Clostridia, but are even less closely...... related to Gram-negative species. Though the Negativicutes stain Gram-negative and possess two membranes, the genome and proteome analysis presented here confirm their place within the (mainly) Gram positive phylum of the Firmicutes. Further studies are required to unveil the evolutionary history...

  7. Two investigational glycylcyclines, DMG-DMDOT and DMG-MINO. Antimicrobial activity studies against gram-positive species.

    Science.gov (United States)

    Johnson, D M; Jones, R N

    1996-01-01

    DMG-DMDOT (CL-331,002 OR CL-331,928) and DMG-MINO (CL-329,998 or CL-344,677) are two new semisynthetic tetracyclines called glycylcyclines, with a broad spectrum of activity and includes Enterobacteriaceae, Gram-positive cocci, JK diphtheroids, and Bacillus cereus. Potent activity was demonstrated against all Streptococcus spp. strains [minimum inhibitory concentrations] (MIC90S) 0.06-0.25 micrograms/ml) and staphylococci (oxacillin susceptible ans resistant; MIC90S 0.12-2 micrograms/ml). Both glycylcyclines (MIC90, 0.06 micrograms/ml) were more potent than minocycline (MIC90 8 micrograms/ml) against Enterococcus faecium, many of which were vancomycin resistant (116 strains). Organisms with minocycline MICs at > or = 8 micrograms/ml (Staphylococcus aureus, enterococci, beta-hemolytic streptococci, and pneumococci) had glycylcycline MIC results ranging from 0.06 to 0.5 micrograms/ml (e.g., apparent use against existing tetracycline-resistance phenotypes). Drugs in this class appear promising for therapy of infections caused by Gram-positive species now testing resistant to contemporary antimicrobial agents, and further development of compounds in this class is encouraged.

  8. Lactobacillus plantarum gene clusters encoding putative cell-surface protein complexes for carbohydrate utilization are conserved in specific gram-positive bacteria

    Directory of Open Access Journals (Sweden)

    Muscariello Lidia

    2006-05-01

    D proteins form cell-surface protein complexes and play a role in carbon source acquisition. Primary occurrence in plant-associated gram-positive bacteria suggests a possible role in degradation and utilization of plant oligo- or poly-saccharides.

  9. Differentiation between spore-forming and asporogenic bacteria using a PCR and southern hybridization based method

    Energy Technology Data Exchange (ETDEWEB)

    Brill, J.A.; Wiegel, J. [Univ. of Georgia, Athens, GA (United States)

    1997-12-31

    A set of molecular probes was devised to develop a method for screening for the presence of sequences homologous to three representative genes exclusively involved in endosporulation. Based on known gene sequences, degenerate PCR primers were designed against spo0A and ssp. Experimental conditions were devised under which homologs of both genes were consistently detected in endospore-forming bacteria, but not in asporogenic bacteria. The PCR amplification products and dpaA/B from Bacillus subtilis were used as hybridization probes for Southern blots. Identical conditions were used with the genomic DNA from endospore-forming and asporogenic bacteria. We therefore concluded that the probes specifically detect the targeted sporulation genes and we obtained no indication that genes homologous to ssp, spo0A and dpaA/B are present in asporogenic bacteria. Thus, this assay can potentially be used to detect spore-forming bacteria in various kinds of samples and to distinguish between bacteria containing sporulation genes and those who do not regardless of whether sporulation is observed or not. 43 refs., 3 figs., 1 tab.

  10. Clostridium difficile infection among immunocompromised patients in Rio de Janeiro, Brazil and detection of moxifloxacin resistance in a ribotype 014 strain.

    Science.gov (United States)

    Secco, Danielle Angst; Balassiano, Ilana Teruszkin; Boente, Renata Ferreira; Miranda, Karla Rodrigues; Brazier, Jon; Hall, Val; dos Santos-Filho, Joaquim; Lobo, Leandro Araujo; Nouér, Simone Aranha; Domingues, Regina Maria Cavalcanti Pilotto

    2014-08-01

    Clostridium difficile is a Gram-positive spore forming anaerobic bacterium, often associated with nosocomial diarrhea and pseudomembranous colitis. The acquisition of this organism occurs primarily in hospitals through accidental ingestion of spores, and its establishment and proliferation in the colon results from the removal of members of the normal intestinal flora during or after antibiotic therapy. In this study, stool samples from patients admitted to the University Hospital Clementino Fraga Filho (HUCCF/UFRJ) were screened for C. difficile toxins with an ELISA test and cultured with standard techniques for C. difficile isolation. A total of 74 stool samples were collected from patients undergoing antibiotic therapy between August 2009 and November 2010, only two (2.7%) were positive in the ELISA test and culture. A third isolate was obtained from a negative ELISA test sample. All cases of CDI were identified in patients with acute lymphoid or myeloid leukemia. Genotypic and phenotypic characterization showed that all strains carried toxins A and B genes, and belonged to PCR-ribotypes 014, 043 and 046. The isolated strains were sensitive to metronidazole and vancomycin, and resistant to ciprofloxacin and levofloxacin. Resistance to moxifloxacin, was present in the strain from PCR-ribotype 014, that showed an amino acid substitution in gyrB gene (Asp 426 → Asn). This is the first time that this mutation in a PCR-ribotype 014 strain has been described in Brazil. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Spore prevalence and toxigenicity of Bacillus cereus and Bacillus thuringiensis isolates from U.S. retail spices.

    Science.gov (United States)

    Hariram, Upasana; Labbé, Ronald

    2015-03-01

    Recent incidents of foodborne illness associated with spices as the vehicle of transmission prompted this examination of U.S. retail spices with regard to Bacillus cereus. This study focused on the levels of aerobic-mesophilic spore-forming bacteria and B cereus spores associated with 247 retail spices purchased from five states in the United States. Samples contained a wide range of aerobic-mesophilic bacterial spore counts (spices had high levels of aerobic spores (> 10(7) CFU/g). Using a novel chromogenic agar, B. cereus and B. thuringiensis spores were isolated from 77 (31%) and 11 (4%) samples, respectively. Levels of B. cereus were spice isolates to form spores, produce diarrheal toxins, and grow at moderately abusive temperatures makes retail spices an important potential vehicle for foodborne illness caused by B. cereus strains, in particular those that produce diarrheal toxins.

  12. Environmental gram-positive mastitis treatment: in vitro sensitivity and bacteriologic cure.

    Science.gov (United States)

    Cattell, M B; Dinsmore, R P; Belschner, A P; Carmen, J; Goodell, G

    2001-09-01

    A clinical trial was conducted in a large dairy herd to determine the efficacy of intramammary pirlimycin hydrochloride administration during lactation for bacteriologic clearance of gram-positive environmental clinical and subclinical mastitis infections. Quarters infected with environmental streptococci that received pirlimycin therapy (13/28) were 1.8 times more likely to resolve infection than untreated quarters (5/14). The small numbers of quarters infected with coagulase-negative staphylococci resulted in inadequate power to assess treatment differences in cure rate. Although the association was not statistically significant, quarters from cows with sensitive environmental streptococci isolates from composite samples (8/13) resolved infection with treatment at approximately twice the rate of treated quarters with resistant isolates (3/10).

  13. Simultaneous fluorescent gram staining and activity assessment of activated sludge bacteria.

    Science.gov (United States)

    Forster, Scott; Snape, Jason R; Lappin-Scott, Hilary M; Porter, Jonathan

    2002-10-01

    Wastewater treatment is one of the most important commercial biotechnological processes, and yet the component bacterial populations and their associated metabolic activities are poorly understood. The novel fluorescent dye hexidium iodide allows assessment of Gram status by differential absorption through bacterial cell walls. Differentiation between gram-positive and gram-negative wastewater bacteria was achieved after flow cytometric analysis. This study shows that the relative proportions of gram-positive and gram-negative bacterial cells identified by traditional microscopy and hexidium iodide staining were not significantly different. Dual staining of cells for Gram status and activity proved effective in analyzing mixtures of cultured bacteria and wastewater populations. Levels of highly active organisms at two wastewater treatment plants, both gram positive and gram negative, ranged from 1.5% in activated sludge flocs to 16% in the activated sludge fluid. Gram-positive organisms comprised Gram status and activity within activated sludge samples over a 4-day period showed significant differences over time. This method provides a rapid, quantitative measure of Gram status linked with in situ activity within wastewater systems.

  14. Techniques for controlling variability in gram staining of obligate anaerobes.

    Science.gov (United States)

    Johnson, M J; Thatcher, E; Cox, M E

    1995-01-01

    Identification of anaerobes recovered from clinical samples is complicated by the fact that certain gram-positive anaerobes routinely stain gram negative; Peptostreptococcus asaccharolyticus, Eubacterium plautii, Clostridium ramosum, Clostridium symbiosum, and Clostridium clostridiiforme are among the nonconformists with regard to conventional Gram-staining procedures. Accurate Gram staining of American Type Culture Collection strains of these anaerobic bacteria is possible by implementing fixing and staining techniques within a gloveless anaerobic chamber. Under anaerobic conditions, gram-positive staining occurred in all test organisms with "quick" fixing techniques with both absolute methanol and formalin. The results support the hypothesis that, when anaerobic bacteria are exposed to oxygen, a breakdown of the physical integrity of the cell wall occurs, introducing Gram stain variability in gram-positive anaerobes. PMID:7538512

  15. Different MRSA ST 398 types in pigs, in human and in hospital

    NARCIS (Netherlands)

    Brase, Katja; Friedrich, Alexander; Koeck, Robin; Nienhoff, Hendrik; Schulte-Wuelwer, Josef; Harlizius, Juergen; van der Wolf, Peter; Klees, Sylvia; Tenhagen, Bernd-Alois; Hanssen, Marlies

    Staphylococcus aureus is a gram-positive bacterium, which occurs frequently on the skin or Mucous membranes of humans and animals. The resistant form of the pathogen gets known as MRSA (methicillin-resistant Staphylococcus aureus). Often, farm animals are called reservoir for MRSA (MRSA-associated

  16. Polyphasic characterization of a PCP-to-phenol dechlorinating microbial community enriched from paddy soil

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Naoko [EcoTopia Science Institute, Nagoya University Nagoya 464-8603 (Japan)]. E-mail: ysd75@esi.nagoya-u.ac.jp; Yoshida, Yukina [Graduate School of Engineering, Nagoya University, Nagoya 464-8603 (Japan); Handa, Yuko [Graduate School of Engineering, Nagoya University, Nagoya 464-8603 (Japan); Kim, Hyo-Keun [Korea Ginseng and Tobacco Research Institute, Taejon 305-345 (Korea, Republic of); Ichihara, Shigeyuki [Faculty of Agriculture, Meijo University, Nagoya 468-8502 (Japan); Katayama, Arata [EcoTopia Science Institute, Nagoya University Nagoya 464-8603 (Japan); Graduate School of Engineering, Nagoya University, Nagoya 464-8603 (Japan)

    2007-08-01

    Dechlorination of PCP has been observed previously under anaerobic condition in paddy soil. However, there is poor information about the dechlorination pathway of PCP and the microbial community associated with the PCP dechlorination in paddy soil. In this study, an anaerobic microbial community dechlorinating PCP was enriched by serial transfers from a paddy soil using a medium containing PCP, lactate and the steam-sterilized paddy soil. The enriched microbial community dechlorinated PCP completely to phenol under the anaerobic condition by a dechlorinating pathway as follows; PCP {sup {yields}} 2,3,4,5-tetrachlorophenol {sup {yields}} 3,4,5-trichlorophenol {sup {yields}} 3,5-dichlorophenol {sup {yields}} 3-chlorophenol {sup {yields}} phenol. Intermediate products such as 3-chlorophenol were not accumulated, which were immediately dechlorinated to phenol. The enriched microbial community was characterized physiologically by testing the effects of electron donors and electron acceptors on the dechlorinating activity. The dechlorinating activity was promoted with lactate, pyruvate, and hydrogen as electron donors but not with acetate. Electron acceptors, nitrate and sulphate, inhibited the dechlorinating activity competitively but not iron (III). The microbial group associated with the anaerobic dechlorination was characterized by the effect of specific inhibitors on the PCP dechlorination. Effects of specific metabolic inhibitors and antibiotics indicated the involvement of Gram-positive spore-forming bacteria with the PCP dechlorinating activity, which was represented as bacteria of phylum Firmicutes. The structure of the microbial community was characterized by fluorescence in situ hybridization, quinone profiling, and PCR-DGGE (denaturing gel gradient electrophoresis). The combined results indicated the predominance of Clostridium species of phylum Firmicutes in the microbial community. Desulfitobacterium spp. known as anaerobic Gram-positive spore-forming

  17. Polyphasic characterization of a PCP-to-phenol dechlorinating microbial community enriched from paddy soil

    International Nuclear Information System (INIS)

    Yoshida, Naoko; Yoshida, Yukina; Handa, Yuko; Kim, Hyo-Keun; Ichihara, Shigeyuki; Katayama, Arata

    2007-01-01

    Dechlorination of PCP has been observed previously under anaerobic condition in paddy soil. However, there is poor information about the dechlorination pathway of PCP and the microbial community associated with the PCP dechlorination in paddy soil. In this study, an anaerobic microbial community dechlorinating PCP was enriched by serial transfers from a paddy soil using a medium containing PCP, lactate and the steam-sterilized paddy soil. The enriched microbial community dechlorinated PCP completely to phenol under the anaerobic condition by a dechlorinating pathway as follows; PCP → 2,3,4,5-tetrachlorophenol → 3,4,5-trichlorophenol → 3,5-dichlorophenol → 3-chlorophenol → phenol. Intermediate products such as 3-chlorophenol were not accumulated, which were immediately dechlorinated to phenol. The enriched microbial community was characterized physiologically by testing the effects of electron donors and electron acceptors on the dechlorinating activity. The dechlorinating activity was promoted with lactate, pyruvate, and hydrogen as electron donors but not with acetate. Electron acceptors, nitrate and sulphate, inhibited the dechlorinating activity competitively but not iron (III). The microbial group associated with the anaerobic dechlorination was characterized by the effect of specific inhibitors on the PCP dechlorination. Effects of specific metabolic inhibitors and antibiotics indicated the involvement of Gram-positive spore-forming bacteria with the PCP dechlorinating activity, which was represented as bacteria of phylum Firmicutes. The structure of the microbial community was characterized by fluorescence in situ hybridization, quinone profiling, and PCR-DGGE (denaturing gel gradient electrophoresis). The combined results indicated the predominance of Clostridium species of phylum Firmicutes in the microbial community. Desulfitobacterium spp. known as anaerobic Gram-positive spore-forming bacteria dechlorinating PCP were not detected by PCR using a

  18. Identification and characterization of a spore-like morphotype in chronically starved Mycobacterium avium subsp. paratuberculosis cultures.

    Directory of Open Access Journals (Sweden)

    Elise A Lamont

    Full Text Available Mycobacteria are able to enter into a state of non-replication or dormancy, which may result in their chronic persistence in soil, aquatic environments, and permissive hosts. Stresses such as nutrient deprivation and hypoxia provide environmental cues to enter a persistent state; however, a clear definition of the mechanism that mycobacteria employ to achieve this remains elusive. While the concept of sporulation in mycobacteria is not novel, it continues to spark controversy and challenges our perceptions of a non-replication. We investigated the potential role of sporulation in one-year old broth cultures of Mycobacterium subsp. paratuberculosis (MAP. We show that dormant cultures of MAP contain a mix of vegetative cells and a previously unknown morphotype resembling a spore. These spore-like structures can be enriched for using sporulating media. Furthermore, purified MAP spore forms survive exposure to heat, lysozyme and proteinase K. Heat-treated spores are positive for MAP 16SrRNA and IS900. MAP spores display enhanced infectivity as well as maintain acid-fast characteristics upon germination in a well-established bovine macrophage model. This is the first study to demonstrate a new MAP morphotype possessing spore-like qualities. Data suggest that sporulation may be a viable mechanism by which MAP accomplishes persistence in the host and/or environment. Thus, our current understanding of mycobacterial persistence, pathogenesis, epidemiology and rational drug and vaccine design may need to be reevaluated.

  19. Rugged single domain antibody detection elements for Bacillus anthracis spores and vegetative cells.

    Directory of Open Access Journals (Sweden)

    Scott A Walper

    Full Text Available Significant efforts to develop both laboratory and field-based detection assays for an array of potential biological threats started well before the anthrax attacks of 2001 and have continued with renewed urgency following. While numerous assays and methods have been explored that are suitable for laboratory utilization, detection in the field is often complicated by requirements for functionality in austere environments, where limited cold-chain facilities exist. In an effort to overcome these assay limitations for Bacillus anthracis, one of the most recognizable threats, a series of single domain antibodies (sdAbs were isolated from a phage display library prepared from immunized llamas. Characterization of target specificity, affinity, and thermal stability was conducted for six sdAb families isolated from rounds of selection against the bacterial spore. The protein target for all six sdAb families was determined to be the S-layer protein EA1, which is present in both vegetative cells and bacterial spores. All of the sdAbs examined exhibited a high degree of specificity for the target bacterium and its spore, with affinities in the nanomolar range, and the ability to refold into functional antigen-binding molecules following several rounds of thermal denaturation and refolding. This research demonstrates the capabilities of these sdAbs and their potential for integration into current and developing assays and biosensors.

  20. Phosphate enhances levan production in the endophytic bacterium Gluconacetobacter diazotrophicus Pal5

    Science.gov (United States)

    Idogawa, Nao; Amamoto, Ryuta; Murata, Kousaku; Kawai, Shigeyuki

    2014-01-01

    Gluconacetobacter diazotrophicus is a gram-negative and endophytic nitrogen-fixing bacterium that has several beneficial effects in host plants; thus, utilization of this bacterium as a biofertilizer in agriculture may be possible. G. diazotrophicus synthesizes levan, a D-fructofuranosyl polymer with β-(2→6) linkages, as an exopolysaccharide and the synthesized levan improves the stress tolerance of the bacterium. In this study, we found that phosphate enhances levan production by G. diazotrophicus Pal5, a wild type strain that showed a stronger mucous phenotype on solid medium containing 28 mM phosphate than on solid medium containing 7 mM phosphate. A G. diazotrophicus Pal5 levansucrase disruptant showed only a weak mucous phenotype regardless of the phosphate concentration, indicating that the mucous phenotype observed on 28 mM phosphate medium was caused by levan. To our knowledge, this is the first report of the effect of a high concentration of phosphate on exopolysaccharide production. PMID:24717418

  1. Spore: Spawning Evolutionary Misconceptions?

    Science.gov (United States)

    Bean, Thomas E.; Sinatra, Gale M.; Schrader, P. G.

    2010-10-01

    The use of computer simulations as educational tools may afford the means to develop understanding of evolution as a natural, emergent, and decentralized process. However, special consideration of developmental constraints on learning may be necessary when using these technologies. Specifically, the essentialist (biological forms possess an immutable essence), teleological (assignment of purpose to living things and/or parts of living things that may not be purposeful), and intentionality (assumption that events are caused by an intelligent agent) biases may be reinforced through the use of computer simulations, rather than addressed with instruction. We examine the video game Spore for its depiction of evolutionary content and its potential to reinforce these cognitive biases. In particular, we discuss three pedagogical strategies to mitigate weaknesses of Spore and other computer simulations: directly targeting misconceptions through refutational approaches, targeting specific principles of scientific inquiry, and directly addressing issues related to models as cognitive tools.

  2. Evaluation of the Verigene Gram-positive blood culture nucleic acid test for rapid detection of bacteria and resistance determinants.

    Science.gov (United States)

    Wojewoda, Christina M; Sercia, Linda; Navas, Maria; Tuohy, Marion; Wilson, Deborah; Hall, Geraldine S; Procop, Gary W; Richter, Sandra S

    2013-07-01

    Rapid identification of pathogens from blood cultures can decrease lengths of stay and improve patient outcomes. We evaluated the accuracy of the Verigene Gram-positive blood culture (BC-GP) nucleic acid test for investigational use only (Nanosphere, Inc., Northbrook, IL) for the identification of Gram-positive bacteria from blood cultures. The detection of resistance genes (mecA in Staphylococcus aureus and Staphylococcus epidermidis and vanA or vanB in Enterococcus faecium and Enterococcus faecalis) by the BC-GP assay also was assessed. A total of 186 positive blood cultures (in BacT/Alert FA bottles) with Gram-positive cocci observed with Gram staining were analyzed using the BC-GP assay. The BC-GP results were compared with the identification and susceptibility profiles obtained with routine methods in the clinical laboratory. Discordant results were arbitrated with additional biochemical, cefoxitin disk, and repeat BC-GP testing. The initial BC-GP organism identification was concordant with routine method results for 94.6% of the blood cultures. Only 40% of the Streptococcus pneumoniae identifications were correct. The detection of the mecA gene for 69 blood cultures with only S. aureus or S. epidermidis was concordant with susceptibility testing results. For 3 of 6 cultures with multiple Staphylococcus spp., mecA detection was reported but was correlated with oxacillin resistance in a species other than S. aureus or S. epidermidis. The detection of vanA agreed with susceptibility testing results for 45 of 46 cultures with E. faecalis or E. faecium. Comparison of the mean times to results for each organism group showed that BC-GP results were available 31 to 42 h earlier than phenotypic identifications and 41 to 50 h earlier than susceptibility results.

  3. Superparamagnetic nickel colloidal nanocrystal clusters with antibacterial activity and bacteria binding ability

    Science.gov (United States)

    Peng, Bo; Zhang, Xinglin; Aarts, Dirk G. A. L.; Dullens, Roel P. A.

    2018-06-01

    Recent progress in synthetic nanotechnology and the ancient use of metals in food preservation and the antibacterial treatment of wounds have prompted the development of nanometallic materials for antimicrobial applications1-4. However, the materials designed so far do not simultaneously display antimicrobial activity and the capability of binding and capturing bacteria and spores. Here, we develop a one-step pyrolysis procedure to synthesize monodisperse superparamagnetic nickel colloidal nanocrystal clusters (SNCNCs), which show both antibacterial activity and the ability to bind Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacteria, as well as bacterial spores. The SNCNCs are formed from a rapid burst of nickel nanoparticles, which self-assemble slowly into clusters. The clusters can magnetically extract 99.99% of bacteria and spores and provide a promising approach for the removal of microbes, including hard-to-treat microorganisms. We believe that our work illustrates the exciting opportunities that nanotechnology offers for alternative antimicrobial strategies and other applications in microbiology.

  4. Gram-positive bacteria of marine origin: a numerical taxonomic study on Mediterranean isolates.

    Science.gov (United States)

    Ortigosa, M; Garay, E; Pujalte, M J

    1997-12-01

    A numerical taxonomic study was performed on 65 Gram-positive wild strains of heterotrophic, aerobic, marine bacteria, and 9 reference strains. The isolates were obtained from oysters and seawater sampled monthly over one year, by direct plating on Marine Agar. The strains were characterized by 96 morphological, biochemical, physiological and nutritional tests. Clustering yielded 13 phena at 0.62 similarity level (Sl coefficient). Only one of the seven phena containing wild isolates could be identified (Bacillus marinus). A pronounced salt requirement was found in most isolates.

  5. Advenella alkanexedens sp. nov., an alkane-degrading bacterium isolated from biogas slurry samples.

    Science.gov (United States)

    Wang, Huimin; Zhou, Shan; Wang, Yanwei; Kong, Delong; Guo, Xiang; Zhu, Jie; Dong, Weiwei; Ruan, Zhiyong

    2016-02-01

    A novel aerobic bacterium, designated strain LAM0050 T , was isolated from a biogas slurry sample, which had been enriched with diesel oil for 30 days. Cells of strain LAM0050 T were gram-stain-negative, non-motile, non-spore-forming and coccoid-shaped. The optimal temperature and pH for growth were 30-35 °C and 8.5, respectively. The strain did not require NaCl for growth, but tolerated up to 5.3 % (w/v) NaCl. Phylogenetic analysis of 16S rRNA gene sequences revealed that strain LAM0050 T was a member of the genus Advenella , and was most closely related to Advenella faeciporci KCTC 23732 T , Advenella incenata CCUG 45225 T , Advenella kashmirensis DSM 17095 T and Advenella mimigardefordensis DSM 17166 T , with 98.1, 96.6, 96.6 and 96.3 % sequence similarity, respectively. The DNA-DNA hybridization relatedness between strain LAM0050 T and A. faeciporci KCTC 23732 T was 41.7 ± 2.4 %. The genomic DNA G+C content was 51.2 mol%, as determined by the T m method. The major fatty acids of strain LAM0050 T were C 16 : 0 , C 17 : 0 cyclo, summed feature 3 (C 16 : 1 ω7 c and/or C 16 : 1 ω6 c ) and summed feature 8 (C 18 : 1 ω7 c and/or C 18 : 1 ω6 c ). The predominant ubiquinone was Q-8. The main polar lipids were diphosphatidyglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine and four unidentified phospholipids. Based on the phenotypic and genotypic properties, strain LAM0050 T is suggested to represent a novel species of the genus Advenella , for which the name Advenella alkanexedens sp. nov., is proposed, the type strain is LAM0050 T ( = ACCC 06485 T  = JCM 30465 T ).

  6. Ferrovibrio soli sp. nov., a novel cellulolytic bacterium isolated from stream bank soil.

    Science.gov (United States)

    Dahal, Ram Hari; Kim, Jaisoo

    2018-01-01

    Two isolates of bacterial strains A15 T and A17 were isolated from stream bank soil in Kyonggi University. Cells were aerobic, Gram-stain-negative, oxidase- and catalase-positive, motile, non-spore-forming, rod-shaped, opaque, and cream coloured. Both strains hydrolysed CM-cellulose. Strains were able to grow at 20-42 °C, pH 5.5-10.0 and at 1.5 % NaCl concentration (w/v). Indole test was positive. Analyses of phylogenetic trees based on its 16S rRNA gene sequences indicated that strain A15 T formed a lineage within the family Rhodospirillaceae of the phylum Proteobacteria which was distinct from Ferrovibrio denitrificans S3 T (98.4 % sequence similarity) and Ferrovibrio xuzhouensis LM-6 T (97.4 %). The sole detected respiratory quinone was Q-10. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and an unidentified aminolipid. The major cellular fatty acids were C19 : 0 cycloω8c, C16 : 0, summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), C18 : 0cyclo and C12 : 0. The DNA G+C contents of strains A15 T and A17 were 63.4 and 62.9 mol%, respectively. DNA-DNA relatedness between strain A15 T and other two members of the genus Ferrovibrioranged from 25 to 37 %. The polyphasic characterization revealed strains A15 T and A17 represent a novel species in the genus Ferrovibrio, for which the name Ferrovibriosoli sp. nov. is proposed. The type strain is A15 T (=KEMB 9005-522 T =KACC 19102 T =NBRC 112682 T ).

  7. Draft Genome Sequence of Pontibacter sp. nov. BAB1700, a Halotolerant, Industrially Important Bacterium

    Science.gov (United States)

    Joshi, M. N.; Sharma, A. C.; Pandya, R. V.; Patel, R. P.; Saiyed, Z. M.; Saxena, A. K.

    2012-01-01

    Pontibacter sp. nov. BAB1700 is a halotolerant, Gram-negative, rod-shaped, pink-pigmented, menaquinone-7-producing bacterium isolated from sediments of a drilling well. The draft genome sequence of the strain, consisting of one chromosome of 4.5 Mb, revealed vital gene clusters involved in vitamin biosynthesis and resistance against various metals and antibiotics. PMID:23105068

  8. Laboratory Investigations on the Survival of Bacillus subtilis Spores in Deliquescent Salt Mars Analog Environments.

    Science.gov (United States)

    Nuding, Danielle L; Gough, Raina V; Venkateswaran, Kasthuri J; Spry, James A; Tolbert, Margaret A

    2017-10-01

    Observed features such as recurring slope lineae suggest that liquid water may exist on the surface and near-subsurface of Mars today. The presence of this liquid water, likely in the form of a brine, has important implications for the present-day water cycle, habitability, and planetary protection policies. It is possible that this water is formed, at least partially, by deliquescence of salts, a process during which hygroscopic salts absorb water vapor from the atmosphere and form a saturated liquid brine. We performed laboratory experiments to examine the ability of Bacillus subtilis (B-168) spores, alone or mixed with calcium perchlorate salt (Ca(ClO 4 ) 2 ), to form liquid water via deliquescence under Mars-relevant conditions. Spore survival after exposure to these conditions was examined. An environmental chamber was used to expose the samples to temperature and relative humidity (RH) values similar to those found on Mars, and Raman microscopy was used to identify the phases of water and salt that were present and to confirm the presence of spores. We found that B-168 spores did not condense any detectable water vapor on their own during the diurnal cycle, even at 100% RH. However, when spores were mixed with perchlorate salt, the entire sample deliquesced at low RH values, immersing the spores in a brine solution during the majority of the simulated martian temperature and humidity cycle. After exposure to the simulated diurnal cycles and, in some cases, perchlorate brine, the impact of each environmental scenario on spore survival was estimated by standard plate assay. We found that, if there are deliquescent salts in contact with spores, there is a mechanism for the spores to acquire liquid water starting with only atmospheric water vapor as the H 2 O source. Also, neither crystalline nor liquid Ca(ClO 4 ) 2 is sporicidal despite the low water activity. Key Words: Raman microscopy-Mars-Planetary protection-Salts-Water activity. Astrobiology 17, 997-1008.

  9. Limit for the Survivability from Potassium Decay of Bacterial Spores in Halite Fluid Inclusions

    Science.gov (United States)

    Kminek, G.; Bada, J. L.

    2001-12-01

    Vreeland et al.1 recently claimed to have isolated and cultured a viable spore forming halotolerant bacterium from a 250 million year old brine inclusion present in a salt crystal from the Salado formation. An earlier report suggested that viable bacterial spores could be revived from samples obtained from insects entombed in 25-40 million year old Dominican amber2. On the bases of these reports, Parkes3 raised the question of whether bacterial spores under some conditions might be effectively immortal. Sporulation, induced by an adverse change in the environmental conditions, is able to stabilize the DNA primarily against hydrolytic depurination for extended periods of time4. However, the organism is still exposed to ionizing radiation from the environment. Dormant spores have a reduced sensitivity to ionizing radiation per se, but unlike active organisms are unable to repair DNA damage encountered during long-term exposure to ionizing radiation. The accumulated damage may overwhelm any repair mechanism that starts in the early stage of spore germination5. The main radionuclide in a halite fluid inclusion is 40K, which accounts for 0.0117% of natural potassium. 40K decays via beta decay to 40Ca and via electron capture to 40Ar, releasing a primary gamma-ray. About 83.3 % of the beta's emitted are in the energy range of 0.3-1.3 MeV. We assume 7 g/l for an average concentration of natural potassium in a halite fluid inclusion, which means that the amount of 40K in a 10 μ l fluid inclusion is 8.19 ng. We have chosen a 10 μ l because this volume is typical of that used to obtain chemical data and in the attempts to extract bacteria. Less than a percent of the gamma decay energy is absorbed in a fluid inclusion of 10 μ l. Thus, we will not take the gamma decay energy into account for the further discussion. Almost all the beta energy is absorbed in the fluid inclusion. The total decay energy absorbed in a time period of 250 million years is about 87 kGy. The most

  10. Development of a Quantitative PCR Assay for Thermophilic Spore-Forming Geobacillus stearothermophilus in Canned Food.

    Science.gov (United States)

    Nakano, Miyo

    2015-01-01

    The thermophilic spore forming bacteria Geobacillus stearothermophilus is recognized as a major cause of spoilage in canned food. A quantitative real-time PCR assay was developed to specifically detect and quantify the species G. stearothermophilus in samples from canned food. The selected primer pairs amplified a 163-bp fragment of the 16S rRNA gene in a specific PCR assay with a detection limit of 12.5 fg of pure culture DNA, corresponding to DNA extracted from approximately 0.7 CFU/mL of G. stearothermophilus. Analysis showed that the bacterial species G. stearothermophilus was not detected in any canned food sample. Our approach presented here will be useful for tracking or quantifying species G. stearotethermophilus in canned food and ingredients.

  11. Complete Genome sequence of Burkholderia phymatum STM815, a broad host range and efficient nitrogen-fixing symbiont of Mimosa species

    Energy Technology Data Exchange (ETDEWEB)

    Moulin, Lionel [UMR, France; Klonowska, Agnieszka [UMR, France; Caroline, Bournaud [UMR, France; Booth, Kristina [University of Massachusetts; Vriezen, Jan A.C. [University of Massachusetts; Melkonian, Remy [UMR, France; James, Euan [James Hutton Institute, Dundee, United Kingdom; Young, Peter W. [University of York, United Kingdom; Bena, Gilles [UMR, France; Hauser, Loren John [ORNL; Land, Miriam L [ORNL; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Bruce, David [Los Alamos National Laboratory (LANL); Chain, Patrick S. G. [Lawrence Livermore National Laboratory (LLNL); Copeland, A [U.S. Department of Energy, Joint Genome Institute; Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Lizotte-Waniewski, Michelle [University of Massachusetts; Bristow, James [U.S. Department of Energy, Joint Genome Institute; Riley, Monica [Woods Hole Oceanographic Institution (WHOI), Woods Hole

    2014-01-01

    Burkholderia phymatum is a soil bacterium able to develop a nitrogen-fixing symbiosis with species of the legume genus Mimosa, and is frequently found associated specifically with Mimosa pudica. The type strain of the species, STM 815T, was isolated from a root nodule in French Guiana in 2000. The strain is an aerobic, motile, non-spore forming, Gram-negative rod, and is a highly competitive strain for nodulation compared to other Mimosa symbionts, as it also nodulates a broad range of other legume genera and species. The 8,676,562 bp genome is composed of two chromosomes (3,479,187 and 2,697,374 bp), a megaplasmid (1,904,893 bp) and a plasmid hosting the symbiotic functions (595,108 bp).

  12. Use of MALDI-TOF Mass Spectrometry for the Fast Identification of Gram-Positive Fish Pathogens

    Science.gov (United States)

    Assis, Gabriella B. N.; Pereira, Felipe L.; Zegarra, Alexandra U.; Tavares, Guilherme C.; Leal, Carlos A.; Figueiredo, Henrique C. P.

    2017-01-01

    Gram-positive cocci, such as Streptococcus agalactiae, Lactococcus garvieae, Streptococcus iniae, and Streptococcus dysgalactiae subsp. dysgalactiae, are found throughout the world, particularly in outbreaks in farmed fish, and are thus associated with high economic losses, especially in the cultivation of Nile Tilapia. The aim of this study was to evaluate the efficacy of matrix-assisted laser desorption ionization (MALDI)-time of flight (TOF) mass spectrometry (MS) as an alternative for the diagnosis of these pathogens. One hundred and thirty-one isolates from Brazilian outbreaks assisted by the national authority were identified using a MALDI Biotyper from Bruker Daltonics. The results showed an agreement with respect to identification (Kappa = 1) between this technique and 16S ribosomal RNA gene sequencing for S. agalactiae and L. garvieae. However, for S. iniae and S. dysgalactiae subsp. dysgalactiae, perfect agreement was only achieved after the creation of a custom main spectra profile, as well as further comparisons with 16S ribosomal RNA and multilocus sequence analysis. MALDI-TOF MS was shown to be an efficient technology for the identification of these Gram-positive pathogens, yielding a quick and precise diagnosis. PMID:28848512

  13. Possible Insecticidal Mechanisms Mediated by Immune-Response-Related Cry-Binding Proteins in the Midgut Juice of Plutella xylostella and Spodoptera exigua.

    Science.gov (United States)

    Lu, Keyu; Gu, Yuqing; Liu, Xiaoping; Lin, Yi; Yu, Xiao-Qiang

    2017-03-15

    Cry toxins are insecticidal toxin proteins produced by a spore-forming Gram-positive bacterium Bacillus thuringiensis. Interactions between the Cry toxins and the receptors from midgut brush border membrane vesicles (BBMVs), such as cadherin, alkaline phosphatase, and aminopeptidase, are key steps for the specificity and insecticidal activity of Cry proteins. However, little is known about the midgut juice proteins that may interfere with Cry binding to the receptors. To validate the hypothesis that there exist Cry-binding proteins that can interfere with the insecticidal process of Cry toxins, we applied Cry1Ab1-coupled Sepharose beads to isolate Cry-binding proteins form midgut juice of Plutella xylostella and Spodoptera exigua. Trypsin-like serine proteases and Dorsal were found to be Cry1Ab1-binding proteins in the midgut juice of P. xylostella. Peroxidase-C (POX-C) was found to be the Cry1Ab1-binding protein in the midgut juice of S. exigua. We proposed possible insecticidal mechanisms of Cry1Ab1 mediated by the two immune-related proteins: Dorsal and POX-C. Our results suggested that there exist, in the midgut juice, Cry-binding proteins, which are different from BBMV-specific receptors.

  14. Fulminant leukemoid reaction due to postpartum Clostridium sordellii infection

    Directory of Open Access Journals (Sweden)

    Prabhat Agrawal

    2012-01-01

    Full Text Available Clostridium sordellii is gram positive anaerobic spore forming rod and it has been demonstrated to cause gas gangrene, refractory shock, leukemoid reaction, and pleuroperitoneal effusion due to capillary leak. We report here a case of postpartum female who presented with leukemoid reaction, ascites, pleural effusion, and shock without fever 7 days after normal vaginal home delivery.

  15. Prediction of lipoprotein signal peptides in Gram-negative bacteria.

    Science.gov (United States)

    Juncker, Agnieszka S; Willenbrock, Hanni; Von Heijne, Gunnar; Brunak, Søren; Nielsen, Henrik; Krogh, Anders

    2003-08-01

    A method to predict lipoprotein signal peptides in Gram-negative Eubacteria, LipoP, has been developed. The hidden Markov model (HMM) was able to distinguish between lipoproteins (SPaseII-cleaved proteins), SPaseI-cleaved proteins, cytoplasmic proteins, and transmembrane proteins. This predictor was able to predict 96.8% of the lipoproteins correctly with only 0.3% false positives in a set of SPaseI-cleaved, cytoplasmic, and transmembrane proteins. The results obtained were significantly better than those of previously developed methods. Even though Gram-positive lipoprotein signal peptides differ from Gram-negatives, the HMM was able to identify 92.9% of the lipoproteins included in a Gram-positive test set. A genome search was carried out for 12 Gram-negative genomes and one Gram-positive genome. The results for Escherichia coli K12 were compared with new experimental data, and the predictions by the HMM agree well with the experimentally verified lipoproteins. A neural network-based predictor was developed for comparison, and it gave very similar results. LipoP is available as a Web server at www.cbs.dtu.dk/services/LipoP/.

  16. Absorption edge imaging of sporocide-treated and non-treated bacterial spores

    International Nuclear Information System (INIS)

    Panessa-Warren, B.J.; Tortora, G.T.; Warren, J.B.

    1987-01-01

    When deprived of nutrients, spore forming bacilli produce endospores which are remarkably resistant to chemical sterilization. Little is known about the morphology and response fo these spores following exposure to sporocidal agents. Light microscopy does not provide sufficient resolution for studying the rupture of the spore coat and fate of intracellular material. Transmission and scanning electron microscopy offer superior resolution but require specimen preparation methods that induce physiologic as well as morphologic changes in the spores, thereby making accurate interpretation of micrographs difficult. To eliminate the possible artifacts induced by chemical fixation, dehydration, embeddment, staining and sectioning, treated and non-sporocide-treated endospores of B. thuringiensis and B. subtilis were imaged by x-ray contact microscopy using monochromatic x-rays. 6 refs., 2 figs

  17. A Sortase A-Immobilized Mesoporous Hollow Carbon Sphere-Based Biosensor for Detection of Gram-Positive Bacteria

    Science.gov (United States)

    Wang, Hongsu; Luo, Ruiping; Chen, Yang; Si, Qi; Niu, Xiaodi

    2018-05-01

    A sensor based on mesoporous carbon materials immobilized with sortase A (SrtA) for determination of Staphylococcus aureus (S. aureus) is reported. To prepare the biosensor, we first synthesized carboxyl-functionalized mesoporous hollow carbon spheres, then applied them as carriers for immobilization of SrtA. Based on the catalytic mechanism of SrtA, a highly sensitive, inexpensive, and rapid method was developed for S. aureus detection. The sensor showed a linear response in the bacterial concentration range of 0.125 × 102 colony-forming units (CFU) mL-1 to 2.5 × 102 CFU mL-1, with detection limit as low as 9.0 CFU mL-1. The method was successfully used for quantitative detection of S. aureus in whole milk samples, giving results similar to experimental results obtained from the plate counting method. This biosensor could also be used to detect other Gram-positive bacteria that secrete SrtA.

  18. Bacillus tamaricis sp. nov., an alkaliphilic bacterium isolated from a Tamarix cone soil.

    Science.gov (United States)

    Zhang, Yong-Guang; Zhou, Xing-Kui; Guo, Jian-Wei; Xiao, Min; Wang, Hong-Fei; Wang, Yun; Bobodzhanova, Khursheda; Li, Wen-Jun

    2018-02-01

    A Gram-stain-positive, alkaliphilic bacterium, designated EGI 80668 T , was isolated from a Tamarix cone soil in Xinjiang, north-west China. Cells were facultatively anaerobic, terminal endospore-forming and motile by means of peritrichous flagella. Colonies were yellowish and the cells showed oxidase-negative and catalase-positive reactions. Strain EGI 80668 T grew at pH 8.0-10.0 and with 0-10 % (w/v) NaCl (optimally at pH 9.0 and with 1-2 % NaCl) on marine agar 2216. The predominant menaquinone was MK-7. The major fatty acids were anteiso-C17 : 0 and anteiso-C15 : 0. The cellular polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, four unknown phospholipids and one unknown aminophospholipid. The G+C content of the genomic DNA was 38.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain EGI 80668 T was affiliated to the genus Bacillus. The highest 16S rRNA gene sequence similarity between strain EGI 80668 T and a member of the genus Bacillus was 96.83 % with Bacillus cellulosilyticus JCM 9156 T . A polyphasic taxonomic study based on morphological, physiological, biochemical and phylogenetic data indicated that strain EGI 80668 T represents a novel species of the genus Bacillus, for which the name Bacillus tamaricis sp. nov. (type strain EGI 80668 T =KCTC 33703 T =CGMCC 1.15917 T ) is proposed.

  19. A method for the determination of bacterial spore DNA content based on isotopic labelling, spore germination and diphenylamine assay; ploidy of spores of several Bacillus species

    International Nuclear Information System (INIS)

    Hauser, P.M.; Karamata, D.

    1992-01-01

    A reliable method for measuring the spore DNA content, based on radioactive DNA labelling, spore germination in absence of DNA replication and diphenylamine assay, was developed. The accuracy of the method, within 10 - 15%, is adequate for determining the number of chromosomes per spore, provided that the genome size is known. B subtilis spores were shown to be invariably monogenomic, while those of larger bacilli Bacillus megaterium, Bacillus cereus and Bacillus thuringiensis, often, if not invariably, contain two genomes. Attempts to modify the spore DNA content of B subtilis by altering the richness of the sporulation medium, the sporulation conditions (liquid or solid medium), or by mutation, were apparently unsuccessful. An increase of spore size with medium richness, not accompanied by an increase in DNA content, was observed. The implication of the apparently species-specific spore ploidy and the influence of the sporulation conditions on spore size and shape are discussed

  20. The Influence of Sporulation Conditions on the Spore Coat Protein Composition of Bacillus subtilis Spores.

    Science.gov (United States)

    Abhyankar, Wishwas R; Kamphorst, Kiki; Swarge, Bhagyashree N; van Veen, Henk; van der Wel, Nicole N; Brul, Stanley; de Koster, Chris G; de Koning, Leo J

    2016-01-01

    Spores are of high interest to the food and health sectors because of their extreme resistance to harsh conditions, especially against heat. Earlier research has shown that spores prepared on solid agar plates have a higher heat resistance than those prepared under a liquid medium condition. It has also been shown that the more mature a spore is, the higher is its heat resistance most likely mediated, at least in part, by the progressive cross-linking of coat proteins. The current study for the first time assesses, at the proteomic level, the effect of two commonly used sporulation conditions on spore protein presence. 14 N spores prepared on solid Schaeffer's-glucose (SG) agar plates and 15 N metabolically labeled spores prepared in shake flasks containing 3-( N -morpholino) propane sulfonic acid (MOPS) buffered defined liquid medium differ in their coat protein composition as revealed by LC-FT-MS/MS analyses. The former condition mimics the industrial settings while the latter conditions mimic the routine laboratory environment wherein spores are developed. As seen previously in many studies, the spores prepared on the solid agar plates show a higher thermal resistance than the spores prepared under liquid culture conditions. The 14 N: 15 N isotopic ratio of the 1:1 mixture of the spore suspensions exposes that most of the identified inner coat and crust proteins are significantly more abundant while most of the outer coat proteins are significantly less abundant for the spores prepared on solid SG agar plates relative to the spores prepared in the liquid MOPS buffered defined medium. Sporulation condition-specific differences and variation in isotopic ratios between the tryptic peptides of expected cross-linked proteins suggest that the coat protein cross-linking may also be condition specific. Since the core dipicolinic acid content is found to be similar in both the spore populations, it appears that the difference in wet heat resistance is connected to the

  1. The Influence of Sporulation Conditions on the Spore Coat Protein Composition of Bacillus subtilis Spores

    Science.gov (United States)

    Abhyankar, Wishwas R.; Kamphorst, Kiki; Swarge, Bhagyashree N.; van Veen, Henk; van der Wel, Nicole N.; Brul, Stanley; de Koster, Chris G.; de Koning, Leo J.

    2016-01-01

    Spores are of high interest to the food and health sectors because of their extreme resistance to harsh conditions, especially against heat. Earlier research has shown that spores prepared on solid agar plates have a higher heat resistance than those prepared under a liquid medium condition. It has also been shown that the more mature a spore is, the higher is its heat resistance most likely mediated, at least in part, by the progressive cross-linking of coat proteins. The current study for the first time assesses, at the proteomic level, the effect of two commonly used sporulation conditions on spore protein presence. 14N spores prepared on solid Schaeffer’s-glucose (SG) agar plates and 15N metabolically labeled spores prepared in shake flasks containing 3-(N-morpholino) propane sulfonic acid (MOPS) buffered defined liquid medium differ in their coat protein composition as revealed by LC-FT-MS/MS analyses. The former condition mimics the industrial settings while the latter conditions mimic the routine laboratory environment wherein spores are developed. As seen previously in many studies, the spores prepared on the solid agar plates show a higher thermal resistance than the spores prepared under liquid culture conditions. The 14N:15N isotopic ratio of the 1:1 mixture of the spore suspensions exposes that most of the identified inner coat and crust proteins are significantly more abundant while most of the outer coat proteins are significantly less abundant for the spores prepared on solid SG agar plates relative to the spores prepared in the liquid MOPS buffered defined medium. Sporulation condition-specific differences and variation in isotopic ratios between the tryptic peptides of expected cross-linked proteins suggest that the coat protein cross-linking may also be condition specific. Since the core dipicolinic acid content is found to be similar in both the spore populations, it appears that the difference in wet heat resistance is connected to the

  2. The influence of sporulation conditions on the spore coat protein composition of Bacillus subtilis spores.

    Directory of Open Access Journals (Sweden)

    Wishwas R. Abhyankar

    2016-10-01

    Full Text Available Spores are of high interest to the food and health sectors because of their extreme resistance to harsh conditions, especially against heat. Earlier research has shown that spores prepared on solid agar plates have a higher heat resistance than those prepared under a liquid medium condition. It has also been shown that the more mature a spore is, the higher is its heat resistance most likely mediated, at least in part, by the progressive cross-linking of coat proteins. The current study for the first time assesses, at the proteomic level, the effect of two commonly used sporulation conditions on spore protein presence. 14N spores prepared on solid SG agar plates and 15N metabolically labelled spores prepared in shake flasks containing MOPS buffered defined liquid medium differ in their coat protein composition as revealed by LC-FT-MS/MS analyses. The former condition mimics the industrial settings while the latter conditions mimic the routine laboratory environment wherein spores are developed. As seen previously in many studies, the spores prepared on the solid agar plates show a higher thermal resistance than the spores prepared under liquid culture conditions. The 14N: 15N isotopic ratio of the 1:1 mixture of the spore suspensions exposes that most of the identified inner coat and crust proteins are significantly more abundant while most of the outer coat proteins are significantly less abundant for the spores prepared on solid SG agar plates relative to the spores prepared in the liquid MOPS buffered defined medium. Sporulation condition-specific differences and variation in isotopic ratios between the tryptic peptides of expected cross-linked proteins suggest that the coat protein cross-linking may also be condition specific. Since the core dipicolinic acid content is found to be similar in both the spore populations, it appears that the difference in wet heat resistance is connected to the differences in the coat protein composition and

  3. Effect of Bacillus thuringiensis parasporal toxin on stimulating of IL-2 and IL-5 cytokines production

    Directory of Open Access Journals (Sweden)

    Marzieh Soleimany

    2018-03-01

    Full Text Available Introduction:Bacillus thuringiensis, is a Gram-positive spore-forming bacterium that produces crystalline parasporal protein (Cry during sporulation. Some of these Cry toxins do not show cytotoxicity against insects but they are capable to kill some human and animal cancer cells. The aim of this study was to verify whether cytocidal parasporal of B thuringiensis strains have immunostimulatory activity on human peripheral blood mononuclear cells (PBMNC and to evaluate the ability of IL-2 and IL-5 production. Materials and methods: B. thuringiensis toxin with cytocidal activity was isolated and treated with proteinase K. PBMNC was cultured and treated with activated crystal proteins. We evaluated the ability of different cytokines production with Flow Cytometry. Results: In this study, immune stimulatory toxins Cry1 were distinguished. This toxin can stimulate production of cytokines IL-2 and stop production of IL-5. Discussion and conclusion: According to anti-cancer effect of B. thuringiensis toxins and also immune stimulatory effect, with more research these toxins can be introduced as immunotherapy drug in cancer treatment.

  4. Clostridial Binary Toxins: Iota and C2 Family Portraits

    Science.gov (United States)

    Stiles, Bradley G.; Wigelsworth, Darran J.; Popoff, Michel R.; Barth, Holger

    2011-01-01

    There are many pathogenic Clostridium species with diverse virulence factors that include protein toxins. Some of these bacteria, such as C. botulinum, C. difficile, C. perfringens, and C. spiroforme, cause enteric problems in animals as well as humans. These often fatal diseases can partly be attributed to binary protein toxins that follow a classic AB paradigm. Within a targeted cell, all clostridial binary toxins destroy filamentous actin via mono-ADP-ribosylation of globular actin by the A component. However, much less is known about B component binding to cell-surface receptors. These toxins share sequence homology amongst themselves and with those produced by another Gram-positive, spore-forming bacterium also commonly associated with soil and disease: Bacillus anthracis. This review focuses upon the iota and C2 families of clostridial binary toxins and includes: (1) basics of the bacterial source; (2) toxin biochemistry; (3) sophisticated cellular uptake machinery; and (4) host–cell responses following toxin-mediated disruption of the cytoskeleton. In summary, these protein toxins aid diverse enteric species within the genus Clostridium. PMID:22919577

  5. Tsukamurella spongiae sp. nov., a novel actinomycete isolated from a deep-water marine sponge.

    Science.gov (United States)

    Olson, Julie B; Harmody, Dedra K; Bej, Asim K; McCarthy, Peter J

    2007-07-01

    A Gram-positive, rod-shaped, non-spore-forming bacterium (strain K362(T)) was isolated from a deep-water marine sponge collected off the coast of Curaçao in the Netherlands Antilles. On the basis of 16S rRNA gene sequence similarities, strain K362(T) was shown to belong to the genus Tsukamurella, being most closely related to Tsukamurella pulmonis (99.2 %), Tsukamurella tyrosinosolvens (98.9 %), Tsukamurella strandjordii (98.8 %), Tsukamurella pseudospumae (98.8 %) and Tsukamurella spumae (98.8 %). A combination of the substrate utilization patterns, the fatty acid and mycolic acid profiles and the DNA-DNA hybridization results supported the affiliation of strain K362(T) to the genus Tsukamurella and enabled the genotypic and phenotypic differentiation of strain K362(T) from the seven recognized Tsukamurella species. Strain K362(T) therefore represents a novel species of the genus Tsukamurella, for which the name Tsukamurella spongiae sp. nov. is proposed. The type strain is K362(T) (=DSM 44990(T)=NRRL B-24467(T)).

  6. Characteristics of a pink-pigmented bacterium isolated from biofilm in a cooling tower in Tokyo, Japan.

    Science.gov (United States)

    Furuhata, Katsunori; Goto, Keiichi; Kato, Yuko; Saitou, Keiko; Sugiyama, Jun-ichi; Hara, Motonobu; Yoshida, Shin-ichi; Fukuyama, Masafumi

    2007-01-01

    Strain K-20, a Gram-negative, non-motile, non-spore-forming and strictly aerobic rod, which produces a pale pink pigment, was isolated from biofilm in a cooling tower in Tokyo, Japan. The taxonomic feature of the strain was studied using phenotypic tests and phylogenetic analysis. Phylogenetic analysis of 16S rRNA gene sequences showed that the strain was related to Roseomonas gilardii subsp. rosea, Roseomonas gilardii subsp. gilardii, Roseomonas cervicalis and Roseomonas mucosa at 94.3-94.6 sequence similarities. Growth occurred at 25-40 C and pH 5.0-10.0, optimal at 35 C and pH 7.0. Growth did not occur in the presence of >or=2% NaCl. The API 20NE identification system gave a positive result for urease, L-arabinose, potassium gluconate, adipic acid, malic acid and trisodium citrate (API code number 0201465). The predominant fatty acids of strain K-20 were C18:1Delta11 (50.8%) and C16:1 (17.2%). Cells contained ubiquinone 10 (Q-10) as the major quinone and the G+C content was 72.0 mol%. Based on phenotypic, chemotaxonomic and phylogenetic data, it was assumed that strain K-20 (=JCM 14634) is a novel species of the genus Roseomonas.

  7. High-level fluorescence labeling of gram-positive pathogens.

    Directory of Open Access Journals (Sweden)

    Simone Aymanns

    Full Text Available Fluorescence labeling of bacterial pathogens has a broad range of interesting applications including the observation of living bacteria within host cells. We constructed a novel vector based on the E. coli streptococcal shuttle plasmid pAT28 that can propagate in numerous bacterial species from different genera. The plasmid harbors a promoterless copy of the green fluorescent variant gene egfp under the control of the CAMP-factor gene (cfb promoter of Streptococcus agalactiae and was designated pBSU101. Upon transfer of the plasmid into streptococci, the bacteria show a distinct and easily detectable fluorescence using a standard fluorescence microscope and quantification by FACS-analysis demonstrated values that were 10-50 times increased over the respective controls. To assess the suitability of the construct for high efficiency fluorescence labeling in different gram-positive pathogens, numerous species were transformed. We successfully labeled Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus dysgalactiae subsp. equisimilis, Enterococcus faecalis, Enterococcus faecium, Streptococcus mutans, Streptococcus anginosus and Staphylococcus aureus strains utilizing the EGFP reporter plasmid pBSU101. In all of these species the presence of the cfb promoter construct resulted in high-level EGFP expression that could be further increased by growing the streptococcal and enterococcal cultures under high oxygen conditions through continuous aeration.

  8. A Comparative biochemical study on two marine endophytes, Bacterium SRCnm and Bacillus sp. JS, Isolated from red sea algae.

    Science.gov (United States)

    Ahmed, Eman Fadl; Hassan, Hossam Mokhtar; Rateb, Mostafa Ezzat; Abdel-Wahab, Noha; Sameer, Somayah; Aly Taie, Hanan Anwar; Abdel-Hameed, Mohammed Sayed; Hammouda, Ola

    2016-01-01

    Two marine endophytic bacteria were isolated from the Red Sea algae; a red alga; Acanthophora dendroides and the brown alga Sargassum sabrepandum. The isolates were identified based on their 16SrRNA sequences as Bacterium SRCnm and Bacillus sp. JS. The objective of this study was to investigate the potential anti-microbial and antioxidant activities of the extracts of the isolated bacteria grown in different nutrient conditions. Compared to amoxicillin (25μg/disk) and erythromycin (15μg/disk), the extracts of Bacterium SRCn min media II, III, IV and V were potent inhibitors of the gram-positive bacterium Sarcina maxima even at low concentrations. Also, the multidrug resistant Staphylococcus aureus(MRSA) was more sensitive to the metabolites produced in medium (II) of the same endophyte than erythromycin (15μg/disk). A moderate activity of the Bacillus sp. JS extracts of media I and II was obtained against the same pathogen. The total compounds (500ug/ml) of both isolated endophytes showed moderate antioxidant activities (48.9% and 46.1%, respectively). LC/MS analysis of the bacterial extracts was carried out to investigate the likely natural products produced. Cyclo(D-cis-Hyp-L-Leu), dihydrosphingosine and 2-Amino-1,3-hexadecanediol were identified in the fermentation medium of Bacterium SRCnm, whereas cyclo (D-Pro-L-Tyr) and cyclo (L-Leu-L-Pro) were the suggested compounds of Bacillus sp. JS.

  9. Crystallization and preliminary X-ray analysis of three dUTPases from Gram-positive bacteria

    International Nuclear Information System (INIS)

    Li, Gui-Lan; Wang, Juan; Li, Lan-Fen; Su, Xiao-Dong

    2009-01-01

    All organisms examined to date possess a dUTPase that performs the important function of efficiently hydrolyzing dUTP to dUMP in order to prevent the incorporation of dUTP into DNA. Three putative dUTPases from Gram-positive bacteria have been studied in this work. All organisms examined to date possess a dUTPase that performs the important function of efficiently hydrolyzing dUTP to dUMP in order to prevent the incorporation of dUTP into DNA. Three putative dUTPases from Gram-positive bacteria have been studied in this work. Two dUTPase-encoding genes, yncF and yosS, have been identified in Bacillus subtilis. The gene dut, encoding dUTPase from the dental pathogen Streptococcus mutans, was amplified from S. mutans genomic DNA. The three genes were cloned into expression vectors and overexpressed at high levels in Escherichia coli. Each protein was purified in two steps using chromatographic methods. Crystals of the YosS and YncF proteins and of S. mutans dUTPase were obtained using the vapour-diffusion method. X-ray diffraction data sets were collected from crystals of selenomethionine-labelled YosS and S. mutans dUTPase to resolutions of 2.3 and 1.7 Å, respectively. The crystal of native YncF diffracted to 2.7 Å resolution

  10. Gram staining apparatus for space station applications

    Science.gov (United States)

    Molina, T. C.; Brown, H. D.; Irbe, R. M.; Pierson, D. L.

    1990-01-01

    A self-contained, portable Gram staining apparatus (GSA) has been developed for use in the microgravity environment on board the Space Station Freedom. Accuracy and reproducibility of this apparatus compared with the conventional Gram staining method were evaluated by using gram-negative and gram-positive controls and different species of bacteria grown in pure cultures. A subsequent study was designed to assess the performance of the GSA with actual specimens. A set of 60 human and environmental specimens was evaluated with the GSA and the conventional Gram staining procedure. Data obtained from these studies indicated that the GSA will provide the Gram staining capability needed for the microgravity environment of space.

  11. Isolated Bacterial Spores at High-velocity Survive Surface Impacts in Vacuum

    Science.gov (United States)

    Austin, Daniel; Barney, Brandon

    We present experiments in which bacterial spores were found to survive being accelerated in vacuum to velocities in the range 30-120 m/s and impacted on a dense target. In these experiments, spores of Bacillus subtilis spores were charged using electrospray at atmospheric pressure, dried, and then introduced into high vacuum. Through choice of skimmers and beam tubes, different velocity ranges were achieved. An image-charge detector observed the charged spores, providing total charge and velocity. The spores then impacted a glass target within a collection vessel. After the experiment, the collection vessel contents were extracted and cultured. Several positive and negative controls were used, including the use of antibiotic-resistant spores and antibiotic-containing (rifampicin) agar for culturing. These impact velocities are of particular interest for possible transport of bacterial spores from Mars to Phobos, and may have implications for planetary protection in a Phobos sample return mission. In addition, bacteria may reach similar velocities during a spacecraft crash (e.g., within components, or from spacecraft to surface materials during impact, etc.), raising concerns about forward contamination. The velocities of interest to transport of life between planets (panspermia) are somewhat higher, but these results complement shock-based experiments and contribute to the general discussion of impact survivability of organisms.

  12. Candidatus Renichlamydia lutjani, a Gram-negative bacterium in internal organs of blue striped snapper Lutjanus kasmira from Hawaii

    Science.gov (United States)

    Corsaro, Daniele; Work, Thierry M.

    2012-01-01

    The blue-striped snapper Lutjanus kasmira (Perciformes, Lutjanidae) are cosmopolitan in the Indo-Pacific but were introduced into Oahu, Hawaii, USA, in the 1950s and have since colonized most of the archipelago. Studies of microparasites in blue-striped snappers from Hawaii revealed chlamydia-like organisms (CLO) infecting the spleen and kidney, characterized by intracellular basophilic granular inclusions containing Gram-negative and Gimenez-positive bacteria similar in appearance to epitheliocysts when seen under light microscopy. We provide molecular evidence that CLO are a new member of Chlamydiae, i.e. Candidatus Renichlamydia lutjani, that represents the first reported case of chlamydial infection in organs other than the gill in fishes.

  13. Fifth international fungus spore conference

    Energy Technology Data Exchange (ETDEWEB)

    Timberlake, W.E.

    1993-04-01

    This folio contains the proceedings of the Fifth International Fungal Spore Conference held August 17-21, 1991 at the Unicoi State Park at Helen, Georgia. The volume contains abstracts of each oral presentation as well as a collection of abstracts describing the poster sessions. Presentations were organized around the themes (1) Induction of Sporulation, (2) Nuclear Division, (3) Spore Formation, (4) Spore Release and Dispersal, and (4) Spore Germination.

  14. The Fungal Spores Survival Under the Low-Temperature Plasma

    Science.gov (United States)

    Soušková, Hana; Scholtz, V.; Julák, J.; Savická, D.

    This paper presents an experimental apparatus for the decontamination and sterilization of water suspension of fungal spores. The fungicidal effect of stabilized positive and negative corona discharges on four fungal species Aspergillus oryzae, Clacosporium sphaerospermum, Penicillium crustosum and Alternaria sp. was studied. Simultaneously, the slower growing of exposed fungal spores was observed. The obtained results are substantially different in comparison with those of the analogous experiments performed with bacteria. It may be concluded that fungi are more resistant to the low-temperature plasma.

  15. Performance and mechanism of standard nano-TiO2(P-25) in photocatalytic disinfection of foodborne microorganisms - salmonella typhimurium and listeria monocytogenes

    Science.gov (United States)

    In this paper, effects of disinfection by nano-TiO2 were studied on the two typical foodborne microorganisms, Gram-negative bacterium Salmonella typhimurium and Gram-positive bacterium-Listeria monocytogenes, in meat products. The performance of nano-TiO2 against the foodborne pathogens was evaluate...

  16. Heavy Metal uptake Potentials of Pseudomonas aeruginosa and ...

    African Journals Online (AJOL)

    Uptake of heavy metals, silver and cadmium by Pseudomonas aeruginosa (a Gram negative bacterium) and Micrococcus luteus (a Gram positive bacterium) was investigated in Cadmium and Silver stock solution using ion selective electrodes. Silver and cadmium uptake by the two organisms was described by Langmuir ...

  17. A Flexible Binding Site Architecture Provides New Insights into CcpA Global Regulation in Gram-Positive Bacteria

    Directory of Open Access Journals (Sweden)

    Yunpeng Yang

    2017-01-01

    Full Text Available Catabolite control protein A (CcpA is the master regulator in Gram-positive bacteria that mediates carbon catabolite repression (CCR and carbon catabolite activation (CCA, two fundamental regulatory mechanisms that enable competitive advantages in carbon catabolism. It is generally regarded that CcpA exerts its regulatory role by binding to a typical 14- to 16-nucleotide (nt consensus site that is called a catabolite response element (cre within the target regions. However, here we report a previously unknown noncanonical flexible architecture of the CcpA-binding site in solventogenic clostridia, providing new mechanistic insights into catabolite regulation. This novel CcpA-binding site, named crevar, has a unique architecture that consists of two inverted repeats and an intervening spacer, all of which are variable in nucleotide composition and length, except for a 6-bp core palindromic sequence (TGTAAA/TTTACA. It was found that the length of the intervening spacer of crevar can affect CcpA binding affinity, and moreover, the core palindromic sequence of crevar is the key structure for regulation. Such a variable architecture of crevar shows potential importance for CcpA’s diverse and fine regulation. A total of 103 potential crevar sites were discovered in solventogenic Clostridium acetobutylicum, of which 42 sites were picked out for electrophoretic mobility shift assays (EMSAs, and 30 sites were confirmed to be bound by CcpA. These 30 crevar sites are associated with 27 genes involved in many important pathways. Also of significance, the crevar sites are found to be widespread and function in a great number of taxonomically different Gram-positive bacteria, including pathogens, suggesting their global role in Gram-positive bacteria.

  18. Effect of Aqueous Garlic Extract (AGE) and gamma irradiation on some Bacterial Strains

    International Nuclear Information System (INIS)

    Awny, N.M; Tawfik, Z.S; Abu Nor, S.M; El-Saled, K.M.

    2005-01-01

    In the present study the sensitivity of four bacterial strains; Salmonella typhimurium, Escherichia coli, Bacillus subtilis and Bacillus pumilus were tested towards the antibacterial effect of aqueous garlic extract (AGE) with different concentration. The results indicated that, the Gram positive spore forming strains, Bacillus subtilis and Bacillus pumilus treated with AGE from 0 to 70μ1/m1 were more resistant than Gram negative non-spore forming ones, Salmonella typhimurium and Escherichia coli treated with AGE from 0 to 24 μ1/m1. The effect of AGE treatment on the radiosensitivity of the tested bacterial strains showed that, AGE treatment before γ-irradiation induced a higher protection than treatment immediately after γ-irradiation. The ultrastructure configuration of untreated strains, treated with AGE or irradiation and combination between AGE and Irradiation, were investigated using transmission electron microscope (TEM). The results indicated that, ultra-structures configuration of the cells treated with AGE before irradiation appeared with less damage than those of cells irradiated without AGE treatment

  19. Antimicrobial susceptibility trends among gram-positive and -negative clinical isolates collected between 2005 and 2012 in Mexico: results from the Tigecycline Evaluation and Surveillance Trial.

    Science.gov (United States)

    Morfin-Otero, Rayo; Noriega, Eduardo Rodriguez; Dowzicky, Michael J

    2015-12-15

    The Tigecycline Evaluation and Surveillance Trial (T.E.S.T) is a global antimicrobial surveillance study of both gram-positive and gram-negative organisms. This report presents data on antimicrobial susceptibility among organisms collected in Mexico between 2005 and 2012 as part of T.E.S.T., and compares rates between 2005-2007 and 2008-2012. Each center in Mexico submitted at least 200 isolates per collection year; including 65 gram-positive isolates and 135 gram-negative isolates. Minimum inhibitory concentrations (MICs) were determined using Clinical Laboratory Standards Institute (CLSI) broth microdilution methodology and antimicrobial susceptibility was established using the 2013 CLSI-approved breakpoints. For tigecycline US Food and Drug Administration (FDA) breakpoints were applied. Isolates of E. coli and K. pneumoniae with a MIC for ceftriaxone of >1 mg/L were screened for ESBL production using the phenotypic confirmatory disk test according to CLSI guidelines. The rates of some key resistant phenotypes changed during this study: vancomycin resistance among Enterococcus faecium decreased from 28.6 % in 2005-2007 to 19.1 % in 2008-2012, while β-lactamase production among Haemophilus influenzae decreased from 37.6 to 18.9 %. Conversely, methicillin-resistant Staphylococcus aureus increased from 38.1 to 47.9 %, meropenem-resistant Acinetobacter spp. increased from 17.7 to 33.0 % and multidrug-resistant Acinetobacter spp. increased from 25.6 to 49.7 %. The prevalence of other resistant pathogens was stable over the study period, including extended-spectrum β-lactamase-positive Escherichia coli (39.0 %) and Klebsiella pneumoniae (25.0 %). The activity of tigecycline was maintained across the study years with MIC90s of ≤2 mg/L against Enterococcus spp., S. aureus, Streptococcus agalactiae, Streptococcus pneumoniae, Enterobacter spp., E. coli, K. pneumoniae, Klebsiella oxytoca, Serratia marcescens, H. influenzae, and Acinetobacter spp. All gram-positive

  20. Concentration and transport of nitrate by the mat-forming sulphur bacterium Thioploca

    Science.gov (United States)

    Fossing, H.; Gallardo, V. A.; Jørgensen, B. B.; Hüttel, M.; Nielsen, L. P.; Schulz, H.; Canfield, D. E.; Forster, S.; Glud, R. N.; Gundersen, J. K.; Küver, J.; Ramsing, N. B.; Teske, A.; Thamdrup, B.; Ulloa, O.

    1995-04-01

    MARINE species of Thioploca occur over 3,000 km along the continental shelf off Southern Peru and North and Central Chile1-4. These filamentous bacteria live in bundles surrounded by a common sheath and form thick mats on the sea floor under the oxygen-minimum zone in the upwelling region, at between 40 and 280 m water depth. The metabolism of this marine bacterium5,6 remained a mystery until long after its discovery1,7. We report here that Thioploca cells are able to concentrate nitrate to up to 500 mM in a liquid vacuole that occupies >80% of the cell volume. Gliding filaments transport this nitrate 5-10 cm down into the sediment and reduce it, with concomitant oxidation of hydrogen sulphide, thereby coupling the nitrogen and sulphur cycles in the sediment.

  1. Ultrastructure and properties of Paecilomyces lilacinus spores

    Energy Technology Data Exchange (ETDEWEB)

    Holland, R.J.; Gunasekera, T.S. [Macquarie Univ., Dept. of Biological Sciences, Sydney (Australia); Williams, K.L. [Proteome Systems Ltd., Sydney (Australia); Nevalainen, K.M.H. [Dept. of Biological Sciences, Macquarie University, Sydney (Australia)

    2002-10-01

    Strains of the filamentous soil fungus Paecilomyces lilacinus are currently being developed for use as biological control agents against root-knot, cyst, and other plant-parasitic nematodes. The inoculum applied in the field consists mainly of spores. This study was undertaken to examine the size, ultrastructure, and rodlet layers of P. lilacinus spores and the effect of the culture method on structural and functional spore properties. A rodlet layer was identified on aerial spores only. Other differences noted between aerial spores and those produced in submerged culture included the size and appearance of spores and thickness of spore coat layers when examined with transmission electron microscopy. The two spore types differed in UV tolerance, with aerial spores being less sensitive to environmentally relevant UV radiation. Also, viability after drying and storage was better with the aerial spores. Both spore types exhibited similar nematophagous ability. (author)

  2. Ultrastructure and properties of Paecilomyces lilacinus spores

    International Nuclear Information System (INIS)

    Holland, R.J.; Gunasekera, T.S.; Williams, K.L.; Nevalainen, K.M.H.

    2002-01-01

    Strains of the filamentous soil fungus Paecilomyces lilacinus are currently being developed for use as biological control agents against root-knot, cyst, and other plant-parasitic nematodes. The inoculum applied in the field consists mainly of spores. This study was undertaken to examine the size, ultrastructure, and rodlet layers of P. lilacinus spores and the effect of the culture method on structural and functional spore properties. A rodlet layer was identified on aerial spores only. Other differences noted between aerial spores and those produced in submerged culture included the size and appearance of spores and thickness of spore coat layers when examined with transmission electron microscopy. The two spore types differed in UV tolerance, with aerial spores being less sensitive to environmentally relevant UV radiation. Also, viability after drying and storage was better with the aerial spores. Both spore types exhibited similar nematophagous ability. (author)

  3. Glucerabacter canisensis gen. nov., sp. nov., isolated from dog feces and its effect on the hydrolysis of plant glucosylceramide in the intestine of dogs.

    Science.gov (United States)

    Kawata, Misho; Tsukamoto, Ami; Isozaki, Ryohei; Nobukawa, Shohei; Kawahara, Natsuki; Akutsu, Shoko; Suzuki, Masato; Asanuma, Narito

    2018-04-01

    A Gram-positive, obligately anaerobic, oval-rod shaped, non-spore-forming, and non-pigmented bacterium, designated strain NATH-2371 T (= JCM31739 T  = DSM105698 T ), was isolated from dog feces. Comparative 16S rRNA gene sequence analysis revealed that strain NATH-2371 T belongs to Clostridium cluster XIVa, and the closest strains were Coprococcus comes ATCC 27758 T (94.8% 16S rRNA gene sequence similarity) and Clostridium nexile DSM 1787 T (94.0%). Strain NATH-2371 T produced acetate, formate, and ethanol from glucose. Predominant cellular fatty acids are C 16:0 and C 16:0 DMA. On the basis of the phenotypic and genotypic differences, strain NATH-2371 T represents a novel species in a new genus of the family Lachnospiraceae, for which the name Glucerabacter canisensis gen. nov., sp. nov., is proposed. This strain was found to efficiently hydrolyze plant glucosylceramide (GluCer). The abundance of strain NATH-2371 T in dog feces was higher in young dogs than in old dogs. Incubation of dog fecal bacteria showed that GluCer-hydrolyzing activity decreased with the age of dogs. The cell number of strain NATH-2371 T in dog feces appeared to be correlated with GluCer hydrolysis. Thus, this bacterium is likely to play a major role in GluCer hydrolysis in the dog intestine.

  4. A New Sensitive GC-MS-based Method for Analysis of Dipicolinic Acid and Quantifying Bacterial Endospores in Deep Marine Subsurface Sediment

    Science.gov (United States)

    Fang, J.

    2015-12-01

    Marine sediments cover more than two-thirds of the Earth's surface and represent a major part of the deep biosphere. Microbial cells and microbial activity appear to be widespread in these sediments. Recently, we reported the isolation of gram-positive anaerobic spore-forming piezophilic bacteria and detection of bacterial endospores in marine subsurface sediment from the Shimokita coalbed, Japan. However, the modern molecular microbiological methods (e.g., DNA-based microbial detection techniques) cannot detect bacterial endospore, because endospores are impermeable and are not stained by fluorescence DNA dyes or by ribosomal RNA staining techniques such as catalysed reporter deposition fluorescence in situ hybridization. Thus, the total microbial cell abundance in the deep biosphere may has been globally underestimated. This emphasizes the need for a new cultivation independent approach for the quantification of bacterial endospores in the deep subsurface. Dipicolinic acid (DPA, pyridine-2,6-dicarboxylic acid) is a universal and specific component of bacterial endospores, representing 5-15wt% of the dry spore, and therefore is a useful indicator and quantifier of bacterial endospores and permits to estimate total spore numbers in the subsurface biosphere. We developed a sensitive analytical method to quantify DPA content in environmental samples using gas chromatography-mass spectrometry. The method is sensitive and more convenient in use than other traditional methods. We applied this method to analyzing sediment samples from the South China Sea (obtained from IODP Exp. 349) to determine the abundance of spore-forming bacteria in the deep marine subsurface sediment. Our results suggest that gram-positive, endospore-forming bacteria may be the "unseen majority" in the deep biosphere.

  5. Veillonella, Firmicutes: Microbes disguised as Gram negatives.

    Science.gov (United States)

    Vesth, Tammi; Ozen, Aslı; Andersen, Sandra C; Kaas, Rolf Sommer; Lukjancenko, Oksana; Bohlin, Jon; Nookaew, Intawat; Wassenaar, Trudy M; Ussery, David W

    2013-12-20

    The Firmicutes represent a major component of the intestinal microflora. The intestinal Firmicutes are a large, diverse group of organisms, many of which are poorly characterized due to their anaerobic growth requirements. Although most Firmicutes are Gram positive, members of the class Negativicutes, including the genus Veillonella, stain Gram negative. Veillonella are among the most abundant organisms of the oral and intestinal microflora of animals and humans, in spite of being strict anaerobes. In this work, the genomes of 24 Negativicutes, including eight Veillonella spp., are compared to 20 other Firmicutes genomes; a further 101 prokaryotic genomes were included, covering 26 phyla. Thus a total of 145 prokaryotic genomes were analyzed by various methods to investigate the apparent conflict of the Veillonella Gram stain and their taxonomic position within the Firmicutes. Comparison of the genome sequences confirms that the Negativicutes are distantly related to Clostridium spp., based on 16S rRNA, complete genomic DNA sequences, and a consensus tree based on conserved proteins. The genus Veillonella is relatively homogeneous: inter-genus pair-wise comparison identifies at least 1,350 shared proteins, although less than half of these are found in any given Clostridium genome. Only 27 proteins are found conserved in all analyzed prokaryote genomes. Veillonella has distinct metabolic properties, and significant similarities to genomes of Proteobacteria are not detected, with the exception of a shared LPS biosynthesis pathway. The clade within the class Negativicutes to which the genus Veillonella belongs exhibits unique properties, most of which are in common with Gram-positives and some with Gram negatives. They are only distantly related to Clostridia, but are even less closely related to Gram-negative species. Though the Negativicutes stain Gram-negative and possess two membranes, the genome and proteome analysis presented here confirm their place within the

  6. Effect of irradiation of bacteria on the formation of spores

    International Nuclear Information System (INIS)

    Szulc, M.; Tropilo, J.; Olszewski, G.

    1980-01-01

    Studies were carried out on bacteria: Bac. subtilis, Bac. cereus, Cl. perfringens, Cl. botulinum which were irradiated in two media (PBS and broth containing 1% of protein) with 100, 1000, 5000 and 10 000 X-radiation doses. The results obtained show that: all bacteria species studied (vegetative forms) are characterized by a high sensitivity to X-radiation, though distinctly lower than the species of Enterobacteriaceae family; the bacteria species studied are characterized by various sporing rate. The highest sporing rate was shown by Bac. cereus, the following: Bac. subtilis, Cl. perfringens and Cl. botulinum; increased X-radiation doses weaken sporing of Bac. subtilis and Bac. cereus. This effect could not be observed in Cl. perfringens and Cl. botulinum. (author)

  7. Effect of irradiation of bacteria on the formation of spores

    Energy Technology Data Exchange (ETDEWEB)

    Szulc, M.; Tropilo, J.; Olszewski, G.

    1980-01-01

    Studies were carried out on bacteria: Bac. subtilis, Bac. cereus, Cl. perfringens, Cl. botulinum which were irradiated in two media (PBS and broth containing 1% of protein) with 100, 1000, 5000 and 10 000 X-radiation doses. The results obtained show that: all bacteria species studied (vegetative forms) are characterized by a high sensitivity to X-radiation, though distinctly lower than the species of Enterobacteriaceae family; the bacteria species studied are characterized by various sporing rate. The highest sporing rate was shown by Bac. cereus, the following: Bac. subtilis, Cl. perfringens and Cl. botulinum; increased X-radiation doses weaken sporing of Bac. subtilis and Bac. cereus. This effect could not be observed in Cl. perfringens and Cl. botulinum.

  8. Non-contiguous finished genome sequence and contextual data of the filamentous soil bacterium Ktedonobacter racemifer type strain (SOSP1-21).

    Science.gov (United States)

    Chang, Yun-Juan; Land, Miriam; Hauser, Loren; Chertkov, Olga; Del Rio, Tijana Glavina; Nolan, Matt; Copeland, Alex; Tice, Hope; Cheng, Jan-Fang; Lucas, Susan; Han, Cliff; Goodwin, Lynne; Pitluck, Sam; Ivanova, Natalia; Ovchinikova, Galina; Pati, Amrita; Chen, Amy; Palaniappan, Krishna; Mavromatis, Konstantinos; Liolios, Konstantinos; Brettin, Thomas; Fiebig, Anne; Rohde, Manfred; Abt, Birte; Göker, Markus; Detter, John C; Woyke, Tanja; Bristow, James; Eisen, Jonathan A; Markowitz, Victor; Hugenholtz, Philip; Kyrpides, Nikos C; Klenk, Hans-Peter; Lapidus, Alla

    2011-10-15

    Ktedonobacter racemifer corrig. Cavaletti et al. 2007 is the type species of the genus Ktedonobacter, which in turn is the type genus of the family Ktedonobacteraceae, the type family of the order Ktedonobacterales within the class Ktedonobacteria in the phylum 'Chloroflexi'. Although K. racemifer shares some morphological features with the actinobacteria, it is of special interest because it was the first cultivated representative of a deep branching unclassified lineage of otherwise uncultivated environmental phylotypes tentatively located within the phylum 'Chloroflexi'. The aerobic, filamentous, non-motile, spore-forming Gram-positive heterotroph was isolated from soil in Italy. The 13,661,586 bp long non-contiguous finished genome consists of ten contigs and is the first reported genome sequence from a member of the class Ktedonobacteria. With its 11,453 protein-coding and 87 RNA genes, it is the largest prokaryotic genome reported so far. It comprises a large number of over-represented COGs, particularly genes associated with transposons, causing the genetic redundancy within the genome being considerably larger than expected by chance. This work is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

  9. A super-family of transcriptional activators regulates bacteriophage packaging and lysis in Gram-positive bacteria

    Science.gov (United States)

    Quiles-Puchalt, Nuria; Tormo-Más, María Ángeles; Campoy, Susana; Toledo-Arana, Alejandro; Monedero, Vicente; Lasa, Íñigo; Novick, Richard P.; Christie, Gail E.; Penadés, José R.

    2013-01-01

    The propagation of bacteriophages and other mobile genetic elements requires exploitation of the phage mechanisms involved in virion assembly and DNA packaging. Here, we identified and characterized four different families of phage-encoded proteins that function as activators required for transcription of the late operons (morphogenetic and lysis genes) in a large group of phages infecting Gram-positive bacteria. These regulators constitute a super-family of proteins, here named late transcriptional regulators (Ltr), which share common structural, biochemical and functional characteristics and are unique to this group of phages. They are all small basic proteins, encoded by genes present at the end of the early gene cluster in their respective phage genomes and expressed under cI repressor control. To control expression of the late operon, the Ltr proteins bind to a DNA repeat region situated upstream of the terS gene, activating its transcription. This involves the C-terminal part of the Ltr proteins, which control specificity for the DNA repeat region. Finally, we show that the Ltr proteins are the only phage-encoded proteins required for the activation of the packaging and lysis modules. In summary, we provide evidence that phage packaging and lysis is a conserved mechanism in Siphoviridae infecting a wide variety of Gram-positive bacteria. PMID:23771138

  10. Bacillus isabeliae sp. nov., a halophilic bacterium isolated from a sea salt evaporation pond.

    Science.gov (United States)

    Albuquerque, Luciana; Tiago, Igor; Taborda, Marco; Nobre, M Fernanda; Veríssimo, António; da Costa, Milton S

    2008-01-01

    A low-G+C, Gram-positive isolate, designated strain CVS-8(T), was isolated from a sea salt evaporation pond on the Island of Sal in the Cape Verde Archipelago. This organism was found to be a catalase- and oxidase-positive, non-motile, spore-forming, aerobic, curved rod-shaped organism with an optimum growth temperature of about 35-37 degrees C and an optimum pH between 7.5 and 8.0. Optimal growth occurred in media containing 4-6% (w/v) NaCl and no growth occurred in medium without NaCl. The cell-wall peptidoglycan was of the A1gamma type with meso-diaminopimelic acid, the major respiratory quinone was MK-7, the major fatty acids were iso-15:0, 16:0, anteiso-15:0 and iso-16:0 and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an unidentified aminoglycophospholipid. The G+C content of the DNA was 37.9 mol%. Phylogenetic analysis of the 16S rRNA gene sequence indicated that strain CVS-8(T) represented a novel species of the genus Bacillus, the highest levels of sequence similarity (mean pairwise similarity values of approximately 97.5 %) being found with respect to the type strains of Bacillus shackletonii and Bacillus acidicola. On the basis of the phylogenetic, physiological and biochemical data, strain CVS-8(T) represents a novel species of the genus Bacillus, for which the name Bacillus isabeliae sp. nov. is proposed. The type strain is CVS-8(T) (=LMG 22838(T)=CIP 108578(T)).

  11. Photometric immersion refractometry of bacterial spores.

    Science.gov (United States)

    Gerhardt, P; Beaman, T C; Corner, T R; Greenamyre, J T; Tisa, L S

    1982-01-01

    Photometric immersion refractometry was used to determine the average apparent refractive index (n) of five types of dormant Bacillus spores representing a 600-fold range in moist-heat resistance determined as a D100 value. The n of a spore type increased as the molecular size of various immersion solutes decreased. For comparison of the spore types, the n of the entire spore and of the isolated integument was determined by use of bovine serum albumin, which is excluded from permeating into them. The n of the sporoplast (the structures bounded by the outer pericortex membrane) was determined by use of glucose, which was shown to permeate into the spore only as deeply as the pericortex membrane. Among the various spore types, an exponential increase in the heat resistance correlated with the n of the entire spore and of the sporoplast, but not of the isolated perisporoplast integument. Correlation of the n with the solids content of the entire spore provided a method of experimentally obtaining the refractive index increment (dn/dc), which was constant for the various spore types and enables the calculation of solids and water content from an n. Altogether, the results showed that the total water content is distributed unequally within the dormant spore, with less water in the sporoplast than in the perisporoplast integument, and that the sporoplast becomes more refractile and therefore more dehydrated as the heat resistance becomes greater among the various spore types. PMID:6802796

  12. An extreme-halophile archaebacterium possesses the interlock type of prephenate dehydratase characteristic of the Gram-positive eubacteria

    Science.gov (United States)

    Jensen, R. A.; d'Amato, T. A.; Hochstein, L. I.

    1988-01-01

    The focal point of phenylalanine biosynthesis is a dehydratase reaction which in different organisms may be prephenate dehydratase, arogenate dehydratase, or cyclohexadienyl dehydratase. Gram-positive, Gram-negative, and cyanobacterial divisions of the eubacterial kingdom exhibit different dehydratase patterns. A new extreme-halophile isolate, which grows on defined medium and is tentatively designated as Halobacterium vallismortis CH-1, possesses the interlock type of prephenate dehydratase present in Gram-positive bacteria. In addition to the conventional sensitivity to feedback inhibition by L-phenylalanine, the phenomenon of metabolic interlock was exemplified by the sensitivity of prephenate dehydratase to allosteric effects produced by extra-pathway (remote) effectors. Thus, L-tryptophan inhibited activity while L-tyrosine, L-methionine, L-leucine and L-isoleucine activated the enzyme. L-Isoleucine and L-phenylalanine were effective at micromolar levels; other effectors operated at mM levels. A regulatory mutant selected for resistance to growth inhibition caused by beta-2-thienylalanine possessed an altered prephenate dehydratase in which a phenomenon of disproportionately low activity at low enzyme concentration was abolished. Inhibition by L-tryptophan was also lost, and activation by allosteric activators was diminished. Not only was sensitivity to feedback inhibition by L-phenylalanine lost, but the mutant enzyme was now activated by this amino acid (a mutation type previously observed in Bacillus subtilis). It remains to be seen whether this type of prephenate dehydratase will prove to be characteristic of all archaebacteria or of some archaebacterial subgroup cluster.

  13. Identification of an entomopathogenic bacterium, Serratia sp. ANU101, and its hemolytic activity.

    Science.gov (United States)

    Kim, Yonggyun; Kim, Keunseob; Seo, Jiae; Shrestha, Sony; Kim, Hosanna H; Nalini, Madanagopal; Yi, Youngkeun

    2009-03-01

    Four different bacterial colonies were isolated from an old stock of an entomopathogenic nematode, Steinernema monticolum. They all showed entomopathogenicity to final instar larvae of beet armyworm, Spodoptera exigua, by hemocoelic injection. However, they varied in colony form, susceptibility to antibiotics, and postmortem change of the infected host insects. Biolog microbial identification and 16S rDNA sequence analyses indicate that these are four different species classified into different bacterial genera. owing to high entomopathogenicity and a cadaver color of infected insect host, Serratia sp. was selected as a main symbiotic bacterial species and analyzed for its pathogenicity. Although no virulence of Serratia sp. was detected at oral administration, the bacteria gave significant synergistic pathogenicity to fifth instar S. exigua when it was treated along with a spore-forming entomopathogenic bacterium, Bacillus thuringiensis. The synergistic effect was explained by an immunosuppressive effect of Serratia sp. by its high cytotoxic effect on hemocytes of S. exigua, because Serratia sp. caused septicemia of S. exigua when the bacterial cells were injected into S. exigua hemocoel. The cytotoxic factor(s) was present in the culture medium because the sterilized culture broth possessed high potency in the cytotoxicity, which was specific to granular cells and plasmatocytes, two main immune-associated hemocytes in insects.

  14. Comparative study on disinfection potency of spore forming bacteria by electron-beam irradiation and gamma-ray irradiation

    International Nuclear Information System (INIS)

    Takizawa, Hironobu; Suzuki, Satoru; Suzuki, Tetsuya; Takama, Kozo; Hayashi, Toru; Yasumoto, Kyoden.

    1990-01-01

    Along with gamma-ray irradiation, electron-beam irradiation (EB) is a method to disinfect microorganisms which cause food decomposition and food-poisoning. The present study was undertaken to compare sterilization efficacy of EB and gamma-ray irradiation on bacterial spores and vegetative cells under various conditions. Spores of Bacillus pumilus, a marker strain for irradiation study, and Bacillus stearothermophilus known as a thermophilic bacteria were irradiated by electron-beam and gamma-ray separately at irradiation dose of 0 to 10 kGy on combination of wet/dry and aerobic/anaerobic conditions. Sterilization effect of irradiation on spores was evaluated by colony counting on agar plates. Results showed that both EB and gamma-ray irradiation gave sufficient sterilization effect on spores, and the sterilization effect increased exponentially with irradiation dose. The sterilization effect of gamma-ray irradiation was higher than that of EB in all cases. Higher disinfection effect was observed under aerobic condition. The present study suggests that oxygen supply in EB is more important than gamma-ray irradiation. No results suggesting that chlorine ion at 0.1 ppm (as available chlorine concentration) enhanced the sterilization efficacy of either EB or gamma-ray irradiation was obtained under any conditions examined. (author)

  15. Comparative study on disinfection potency of spore forming bacteria by electron-beam irradiation and gamma-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Takizawa, Hironobu; Suzuki, Satoru; Suzuki, Tetsuya; Takama, Kozo [Hokkaido Univ., Hakodate (Japan). Faculty of Fisheries; Hayashi, Toru; Yasumoto, Kyoden

    1990-10-01

    Along with gamma-ray irradiation, electron-beam irradiation (EB) is a method to disinfect microorganisms which cause food decomposition and food-poisoning. The present study was undertaken to compare sterilization efficacy of EB and gamma-ray irradiation on bacterial spores and vegetative cells under various conditions. Spores of Bacillus pumilus, a marker strain for irradiation study, and Bacillus stearothermophilus known as a thermophilic bacteria were irradiated by electron-beam and gamma-ray separately at irradiation dose of 0 to 10 kGy on combination of wet/dry and aerobic/anaerobic conditions. Sterilization effect of irradiation on spores was evaluated by colony counting on agar plates. Results showed that both EB and gamma-ray irradiation gave sufficient sterilization effect on spores, and the sterilization effect increased exponentially with irradiation dose. The sterilization effect of gamma-ray irradiation was higher than that of EB in all cases. Higher disinfection effect was observed under aerobic condition. The present study suggests that oxygen supply in EB is more important than gamma-ray irradiation. No results suggesting that chlorine ion at 0.1 ppm (as available chlorine concentration) enhanced the sterilization efficacy of either EB or gamma-ray irradiation was obtained under any conditions examined. (author).

  16. Spore membrane(s) as the site of damage within heated Clostridium perfringens spores.

    Science.gov (United States)

    Flowers, R S; Adams, D M

    1976-02-01

    Clostridium perfringens spores were injured by ultrahigh-temperature treatment at 105 C for 5 min. Injury was manifested as an increased sensitivity to polymyxin and neomycin. Since many of the survivors could not germinate normally the ultrahigh-temperature-treated spores were sensitized to and germinated by lysozyme. Polymyxin reportedly acts upon the cell membrane. Neomycin may inhibit protein synthesis and has surface-active properties. Injured spores were increasingly sensitive to known surface-active agents, sodium lauryl sulfate, sodium deoxycholate, and Roccal, a quaternary ammonium compound. Injured spores sensitive to polymyxin and neomycin also were osmotically fragile and died during outgrowth in a liquid medium unless the medium was supplemented with 20% sucrose, 10% dextran, or 10% polyvinylpyrrolidone. The results suggested that a spore structure destined to become cell membrane or cell wall was the site of injury. Repair of injury during outgrowth in the presence of protein, deoxyribonucleic acid, ribonucleic acid and cell wall synthesis inhibitors was consistent with this hypothesis.

  17. Extracellular Electron Transfer Mediated by Flavins in Gram-positive Bacillus sp. WS-XY1 and Yeast Pichia stipitis

    International Nuclear Information System (INIS)

    Wu, Song; Xiao, Yong; Wang, Lu; Zheng, Yue; Chang, Kenlin; Zheng, Zhiyong; Yang, Zhaohui; Varcoe, John R.; Zhao, Feng

    2014-01-01

    Extracellular electron transfer (EET) of microorganisms represents a communicative bridge between the interior and exterior of the cells. Most prior EET studies have focused on Gram-negative bacteria. However, fungi and Gram-positive bacteria, that contain dense cellular walls, have rarely been reported. Herein, two model dense cell wall microorganisms (Bacillus sp. WS-XY1 and the yeast Pichia stipitis) were identified to be electrochemically active. Further analysis indicated that the two microorganisms were able to secrete flavins to mediate their EET. The discovery, that dense cell wall containing microorganisms can undertake mediated EET, adds to the body of knowledge towards building a comprehensive understanding of biogeochemical and bioelectrical processes

  18. The search and identification of the new immunodiagnostic targets of bacillus anthracis spore

    International Nuclear Information System (INIS)

    Biketov, S.; Dunaytsev, I.; Baranova, E.; Marinin, L.; Dyatlov, I.

    2009-01-01

    Spores of Bacillus anthracis have been used as bio warfare agent to bio terrorize purposes. As efficiency of anti-epidemic measures included urgent prevention and treatment is determined by terms within which the bio agent is identified. Direct and rapid spore detection by antibodies based detection system is very attractive alternative to current PCR-based assays or routine phenotyping which are the most accurate but are also complex, time-consumption and expensive. The main difficulty with respect to such kind of anthrax spores detection is a cross-reaction with spores of closely related bacteria. For development of species-specific antibodies to anthrax spores recombinant scFvs or hybridoma technique were used. In both case surface spore antigens contained species-specific epitopes are need. Among exosporium proteins only ExsF(BxpB), ExsK and SoaA are specific to B.cereus group. On the surface of B. anthracis spores, a unique tetrasaccharides containing an novel monosaccharide - anthrose, was discovered. It was shown that anthrose can be serving as species-specific target for B. anthracis spores detection. We have revealed that EA1 isolated from spore of Russians strain STI-1 contain carbohydrate which formed species-specific epitopes and determine immunogenicity of this antigen. Antibodies to this antigen specifically recognized the surface target of B. anthracis spores and do not reacted with others Bacillus spore. Based on these antibodies we developed the test-systems in different formats for rapid direct detection and identification of B. anthracis spores. The results of trial these test-systems with using more than 50 different Bacillus strains were indicated that carbohydrate of EA1 isolated from spore is effective immunodiagnostic target for anthrax spores bio detection.(author)

  19. Antimicrobial effects of zero-valent iron nanoparticles on gram-positive Bacillus strains and gram-negative Escherichia coli strains

    Directory of Open Access Journals (Sweden)

    Yi-Huang Hsueh

    2017-11-01

    Full Text Available Abstract Background Zero-valent iron nanoparticles (ZVI NPs have been used extensively for the remediation of contaminated soil and groundwater. Owing to their large active surface area, they serve as strong and effective reductants. However, the ecotoxicity and bioavailability of ZVI NPs in diverse ecological media have not been evaluated in detail and most studies have focused on non-nano ZVI or Fe0. In addition, the antimicrobial properties of ZVI NPs have rarely been investigated, and the underlying mechanism of their toxicity remains unknown. Results In the present study, we demonstrate that ZVI NPs exhibited significant toxicity at 1000 ppm against two distinct gram-positive bacterial strains (Bacillus subtilis 3610 and Bacillus thuringiensis 407 but not against two gram-negative strains (Escherichia coli K12 and ATCC11634. Specifically, ZVI NPs caused at least a 4-log and 1-log reductions in cell numbers, respectively, in the two Bacillus strains, whereas no change was detected in the two E. coli strains. X-ray photoelectron spectroscopy, X-ray absorption near-edge, and extended X-ray absorption fine structure spectra confirmed that Bacillus cells exposed to ZVI NPs contained mostly Fe2O3 with some detectable FeS. This finding indicated that Fe0 nanoparticles penetrated the bacterial cells, where they were subsequently oxidized to Fe2O3 and FeS. RedoxSensor analysis and propidium iodide (PI staining showed decreased reductase activity and increased PI in both Bacillus strains treated with a high (1000 ppm concentration of ZVI NPs. Conclusion Taken together, these data show that the toxicity of ZVI NPs was derived from their oxidative properties, which may increase the levels of reactive oxygen species and lead to cell death.

  20. A fatal endocarditis case due to an emerging bacterium: Moraxella nonliquefaciens

    Directory of Open Access Journals (Sweden)

    C. Duployez

    2017-01-01

    Full Text Available Moraxella nonliquefaciens is a Gram-negative coccobacillus considered as a commensal organism from the upper respiratory tract, with low pathogenic potential. The phenotypical conventional identification is difficult and the matrix-assisted laser desorption/ionization time-of-flight technology has increased the resolution of identification of this bacterium. We report a fatal case of endocarditis due to M. nonliquefaciens whose identification was confirmed by 16S rRNA, and we review the literature on this pathogen in endocarditis.

  1. Effects of High Pressure on Bacillus licheniformis Spore Germination and Inactivation.

    Science.gov (United States)

    Borch-Pedersen, Kristina; Mellegård, Hilde; Reineke, Kai; Boysen, Preben; Sevenich, Robert; Lindbäck, Toril; Aspholm, Marina

    2017-07-15

    Bacillus and Clostridium species form spores, which pose a challenge to the food industry due to their ubiquitous nature and extreme resistance. Pressurization at 300 MPa likely triggers germination by opening dipicolinic acid (DPA) channels present in the inner membrane of the spores. In this work, we expose spores of Bacillus licheniformis , a species associated with food spoilage and occasionally with food poisoning, to high pressure (HP) for holding times of up to 2 h. By using mutant spores lacking one or several GRs, we dissect the roles of the GerA, Ynd, and GerK GRs in moderately HP (mHP; 150 MPa)-induced spore germination. We show that Ynd alone is sufficient for efficient mHP-induced spore germination. GerK also triggers germination with mHP, although at a reduced germination rate compared to that of Ynd. GerA stimulates mHP-induced germination but only in the presence of either the intact GerK or Ynd GR. These results suggests that the effectiveness of the individual GRs in mHP-induced germination differs from their effectiveness in nutrient-induced germination, where GerA plays an essential role. In contrast to Bacillus subtilis spores, treatment with very HP (vHP) of 550 MPa at 37°C did not promote effective germination of B. licheniformis spores. However, treatment with vHP in combination with elevated temperatures (60°C) gave a synergistic effect on spore germination and inactivation. Together, these results provide novel insights into how HP affects B. licheniformis spore germination and inactivation and the role of individual GRs in this process. IMPORTANCE Bacterial spores are inherently resistant to food-processing regimes, such as high-temperature short-time pasteurization, and may therefore compromise food durability and safety. The induction of spore germination facilitates subsequent inactivation by gentler processing conditions that maintain the sensory and nutritional qualities of the food. High-pressure (HP) processing is a nonthermal

  2. The characterisation of Bacillus spores occurring in the manufacturing of (low acid) canned products

    NARCIS (Netherlands)

    Oomes, S.J.C.M.; Zuijlen, A.C.M. van; Hehenkamp, J.O.; Witsenboer, H.; Vossen, J.M.B.M. van der; Brul, S.

    2007-01-01

    Spore-forming bacteria can be a problem in the food industry, especially in the canning industry. Spores present in ingredients or present in the processing environment severely challenge the preservation process since their thermal resistance may be very high. We therefore asked the question which

  3. Partial genome sequence of Thioalkalivibrio thiocyanodenitrificans ARhD 1T, a chemolithoautotrophic haloalkaliphilic sulfur-oxidizing bacterium capable of complete denitrification

    NARCIS (Netherlands)

    Berben, T.; Sorokin, D.Y.; Ivanova, N.; Pati, A.; Kyrpides, N.; Goodwin, L.A; Woyke, T.; Muyzer, G.

    2015-01-01

    Thioalkalivibrio thiocyanodenitrificans strain ARhD 1 T is a motile, Gram-negative bacterium isolated from soda lakes that belongs to the Gammaproteobacteria. It derives energy for growth and carbon fixation from the oxidation of sulfur compounds, most notably thiocyanate, and so is a

  4. Non-contiguous finished genome sequence and contextual data of the filamentous soil bacterium Ktedonobacter racemifer type strain (SOSP1-21T)

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Yun-Juan [ORNL; Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Chertkov, Olga [Los Alamos National Laboratory (LANL); Glavina Del Rio, Tijana [U.S. Department of Energy, Joint Genome Institute; Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Copeland, A [U.S. Department of Energy, Joint Genome Institute; Tice, Hope [U.S. Department of Energy, Joint Genome Institute; Cheng, Jan-Fang [U.S. Department of Energy, Joint Genome Institute; Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Han, Cliff [Los Alamos National Laboratory (LANL); Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Ivanova, N [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 [U.S. Department of Energy, Joint Genome Institute; Palaniappan, Krishna [U.S. Department of Energy, Joint Genome Institute; Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Liolios, Konstantinos [U.S. Department of Energy, Joint Genome Institute; Brettin, Thomas S [ORNL; Fiebig, Anne [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Rohde, Manfred [HZI - Helmholtz Centre for Infection Research, Braunschweig, Germany; Abt, Birte [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Goker, Markus [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Bristow, James [U.S. Department of Energy, Joint Genome Institute; Eisen, Jonathan [U.S. Department of Energy, Joint Genome Institute; Markowitz, Victor [U.S. Department of Energy, Joint Genome Institute; Hugenholtz, Philip [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Klenk, Hans-Peter [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute

    2011-01-01

    Ktedonobacter racemifer corrig. Cavaletti et al. 2007 is the type species of the genus Ktedo- nobacter, which in turn is the type genus of the family Ktedonobacteraceae, the type family of the order Ktedonobacterales within the class Ktedonobacteria in the phylum Chloroflexi . Although K. racemifer shares some morphological features with the actinobacteria, it is of special interest because it was the first cultivated representative of a deep branching unclassi- fied lineage of otherwise uncultivated environmental phylotypes tentatively located within the phylum Chloroflexi . The aerobic, filamentous, non-motile, spore-forming Gram-positive heterotroph was isolated from soil in Italy. The 13,661,586 bp long non-contiguous finished genome consists of ten contigs and is the first reported genome sequence from a member of the class Ktedonobacteria. With its 11,453 protein-coding and 87 RNA genes, it is the largest prokaryotic genome reported so far. It comprises a large number of over-represented COGs, particularly genes associated with transposons, causing the genetic redundancy within the genome being considerably larger than expected by chance. This work is a part of the Ge- nomic Encyclopedia of Bacteria and Archaea project.

  5. Effect of pH on Thermoanaerobacterium thermosaccharolyticum DSM 571 growth, spore heat resistance and recovery.

    Science.gov (United States)

    Mtimet, Narjes; Guégan, Stéphanie; Durand, Lucile; Mathot, Anne-Gabrielle; Venaille, Laurent; Leguérinel, Ivan; Coroller, Louis; Couvert, Olivier

    2016-05-01

    Thermophilic spore-forming bacteria are potential contaminants in several industrial sectors involving high temperatures (40-65 °C) in the manufacturing process. Among those thermophilic spore-forming bacteria, Thermoanaerobacterium thermosaccharolyticum, called "the swelling canned food spoiler", has generated interest over the last decade in the food sector. The aim of this study was to investigate and to model pH effect on growth, heat resistance and recovery abilities after a heat-treatment of T. thermosaccharolyticum DSM 571. Growth and sporulation were conducted on reinforced clostridium media and liver broth respectively. The highest spore heat resistances and the greatest recovery ability after a heat-treatment were obtained at pH condition allowing maximal growth rate. Growth and sporulation boundaries were estimated, then models using growth limits as main parameters were extended to describe and quantify the effect of pH on recovery of injured spores after a heat-treatment. So, cardinal values were used as a single set of parameters to describe growth, sporulation and recovery abilities. Besides, this work suggests that T. thermosaccharolyticum preserve its ability for germination and outgrowth after a heat-treatment at a low pH where other high resistant spore-forming bacteria like Geobacillus stearothermophilus are unable to grow. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Olsenella umbonata sp. nov., a microaerotolerant anaerobic lactic acid bacterium from the sheep rumen and pig jejunum, and emended descriptions of Olsenella, Olsenella uli and Olsenella profusa.

    Science.gov (United States)

    Kraatz, Mareike; Wallace, R John; Svensson, Liselott

    2011-04-01

    Strain A2 is an anaerobic, variably Gram-stain-positive, non-spore-forming, small and irregularly rod-shaped bacterium from the ruminal fluid of a sheep that has been described informally as a representative of 'Olsenella (basonym Atopobium) oviles'. Three phenotypically similar bacterial strains (lac15, lac16 and lac31(T)) were isolated in concert with Veillonella magna lac18(T) from the mucosal jejunum of a pig. A phylogenetic analysis based on 16S rRNA gene sequences revealed that strains A2, lac15, lac16 and lac31(T) formed a genetically coherent group (100 % interstrain sequence similarity) within the bigeneric Olsenella-Atopobium branch of the family Coriobacteriaceae, class Actinobacteria. This group was most closely related to the type strains of the two recognized Olsenella species, namely Olsenella uli (sequence similarity of 96.85 %) and Olsenella profusa (sequence similarity of 97.20 %). The sequence similarity to the type strain of Atopobium minutum, the type species of the genus Atopobium, was 92.33 %. Unlike those of O. uli and O. profusa, outgrown colonies of strains A2, lac15, lac16 and lac31(T) were opaque and greyish-white with an umbonate elevation on solid culture media. The four novel strains were characterized as being well-adapted and presumably indigenous to the gastrointestinal tract of homoeothermic vertebrates: they were mesophilic, microaerotolerant, neutrophilic and acidotolerant, bile-resistant, mucin-utilizing and markedly peptidolytic lactic acid bacteria. The results of DNA-DNA hybridizations, cellular fatty acid analysis and other differential phenotypic (physiological and biochemical) tests confirmed that strains A2, lac15, lac16 and lac31(T) represent a novel species of the genus Olsenella. On the basis of the genotypic and phenotypic results, we therefore describe Olsenella umbonata sp. nov., with lac31(T) ( = CCUG 58604(T)  = DSM 22620(T)  = JCM 16156(T)) as the type strain and A2 ( = CCUG 58212

  7. In vivo metabolism of 2,2'-diaminopimelic acid from gram-positive and gram-negative bacterial cells by ruminal microorganisms and ruminants and its use as a marker of bacterial biomass

    International Nuclear Information System (INIS)

    Masson, H.A.; Denholm, A.M.; Ling, J.R.

    1991-01-01

    Cells of Bacillus megaterium GW1 and Escherichia coli W7-M5 were specifically radiolabeled with 2,2'-diamino [G- 3 H] pimelic acid ([ 3 H]DAP) as models of gram-positive and gram-negative bacteria, respectively. Two experiments were conducted to study the in vivo metabolism of 2,2'-diaminopimelic acid (DAP) in sheep. In experiment 1, cells of [ 3 H]DAP-labeled B. megaterium GW1 were infused into the rumen of one sheep and the radiolabel was traced within microbial samples, digesta, and the whole animal. Bacterially bound [ 3 H]DAP was extensively metabolized, primarily (up to 70% after 8 h) via decarboxylation to [ 3 H]lysine by both ruminal protozoa and ruminal bacteria. Recovery of infused radiolabel in urine and feces was low (42% after 96 h) and perhaps indicative of further metabolism by the host animal. In experiment 2, [ 3 H]DAP-labeled B. megaterium GW1 was infused into the rumens of three sheep and [ 3 H]DAP-labeled E. coli W7-W5 was infused into the rumen of another sheep. The radioactivity contents of these mutant bacteria were insufficient to use as tracers, but the metabolism of DAP was monitored in the total, free, and peptidyl forms. Free DAP, as a proportion of total DPA in duodenal digesta, varied from 0 to 9.5%, whereas peptidyl DAP accounted for 8.3 to 99.2%

  8. Isolation of a 250 million-year-old halotolerant bacterium from a primary salt crystal

    Science.gov (United States)

    Vreeland, Russell H.; Rosenzweig, William D.; Powers, Dennis W.

    2000-10-01

    Bacteria have been found associated with a variety of ancient samples, however few studies are generally accepted due to questions about sample quality and contamination. When Cano and Borucki isolated a strain of Bacillus sphaericus from an extinct bee trapped in 25-30 million-year-old amber, careful sample selection and stringent sterilization techniques were the keys to acceptance. Here we report the isolation and growth of a previously unrecognized spore-forming bacterium (Bacillus species, designated 2-9-3) from a brine inclusion within a 250million-year-old salt crystal from the Permian Salado Formation. Complete gene sequences of the 16S ribosomal DNA show that the organism is part of the lineage of Bacillus marismortui and Virgibacillus pantothenticus. Delicate crystal structures and sedimentary features indicate the salt has not recrystallized since formation. Samples were rejected if brine inclusions showed physical signs of possible contamination. Surfaces of salt crystal samples were sterilized with strong alkali and acid before extracting brines from inclusions. Sterilization procedures reduce the probability of contamination to less than 1 in 10 9.

  9. Sporulation environment influences spore properties in Bacillus: evidence and insights on underlying molecular and physiological mechanisms.

    Science.gov (United States)

    Bressuire-Isoard, Christelle; Broussolle, Véronique; Carlin, Frédéric

    2018-05-17

    Bacterial spores are resistant to physical and chemical insults, which make them a major concern for public health and for industry. Spores help bacteria to survive extreme environmental conditions that vegetative cells cannot tolerate. Spore resistance and dormancy are important properties for applications in medicine, veterinary health, food safety, crop protection, and other domains. The resistance of bacterial spores results from a protective multilayered structure and from the unique composition of the spore core. The mechanisms of sporulation and germination, the first stage after breaking of dormancy, and organization of spore structure have been extensively studied in Bacillus species. This review aims to illustrate how far the structure, composition and properties of spores are shaped by the environmental conditions in which spores form. We look at the physiological and molecular mechanisms underpinning how sporulation media and environment deeply affect spore yield, spore properties like resistance to wet heat and physical and chemical agents, germination, and further growth. For example, spore core water content decreases as sporulation temperature increases, and resistance to wet heat increases. Controlling the fate of Bacillus spores is pivotal to controlling bacterial risks and process efficiencies in, for example, the food industry, and better control hinges on better understanding how sporulation conditions influence spore properties.

  10. Protein Composition of Infectious Spores Reveals Novel Sexual Development and Germination Factors in Cryptococcus.

    Directory of Open Access Journals (Sweden)

    Mingwei Huang

    2015-08-01

    Full Text Available Spores are an essential cell type required for long-term survival across diverse organisms in the tree of life and are a hallmark of fungal reproduction, persistence, and dispersal. Among human fungal pathogens, spores are presumed infectious particles, but relatively little is known about this robust cell type. Here we used the meningitis-causing fungus Cryptococcus neoformans to determine the roles of spore-resident proteins in spore biology. Using highly sensitive nanoscale liquid chromatography/mass spectrometry, we compared the proteomes of spores and vegetative cells (yeast and identified eighteen proteins specifically enriched in spores. The genes encoding these proteins were deleted, and the resulting strains were evaluated for discernable phenotypes. We hypothesized that spore-enriched proteins would be preferentially involved in spore-specific processes such as dormancy, stress resistance, and germination. Surprisingly, however, the majority of the mutants harbored defects in sexual development, the process by which spores are formed. One mutant in the cohort was defective in the spore-specific process of germination, showing a delay specifically in the initiation of vegetative growth. Thus, by using this in-depth proteomics approach as a screening tool for cell type-specific proteins and combining it with molecular genetics, we successfully identified the first germination factor in C. neoformans. We also identified numerous proteins with previously unknown functions in both sexual development and spore composition. Our findings provide the first insights into the basic protein components of infectious spores and reveal unexpected molecular connections between infectious particle production and spore composition in a pathogenic eukaryote.

  11. Alternate gram staining technique using a fluorescent lectin.

    Science.gov (United States)

    Sizemore, R K; Caldwell, J J; Kendrick, A S

    1990-01-01

    Fluorescence-labeled wheat germ agglutinin binds specifically to N-acetylglucosamine in the outer peptidoglycan layer of gram-positive bacteria. The peptidoglycan layer of gram-negative bacteria is covered by a membrane and is not labeled by the lectin. By exploiting this phenomenon, an alternative Gram staining technique has been developed. Images PMID:1697149

  12. Inactivation of Lactobacillus plantarum in apple cider using radio frequency electric fields

    Science.gov (United States)

    Radio frequency electric fields (RFEF) processing is effective at inactivating Gram negative bacteria in fruit juices at moderately low temperatures, but has yet to be shown to be effective at reducing Gram positive bacteria. Lactobacillus plantarum ATCC 49445, a Gram positive bacterium, was inocula...

  13. The occurrence of Ganoderma spores in the air and its relationships with meteorological factors

    Directory of Open Access Journals (Sweden)

    Agnieszka Grinn-Gofroń

    2012-12-01

    Full Text Available According to a recent study, Ganoderma may be the third genus, after Alternaria and Cladosporium, whose spores cause symptoms of allergy and whose levels are directly related to meteorological factors. There are only few articles from different parts of the world about the relationships between Ganoderma spore count and meteorological factors. The aim of the study was to review all available publications about airborne Ganoderma spores and to compare the results in a short useful form.

  14. In vitro mutagenesis of commercial fern, Asplenium nidus from spores

    International Nuclear Information System (INIS)

    Norazlina Noordin

    2004-01-01

    Asplenium is a largest, most diverse fern genera. One of the common species is Asplenium nidus, well known as Bird's-nest fern, a medium to large fern with erect, stout, unbranched rhizomes. In creating variability of ferns for the benefit of the ornamental plant industry, in vitro mutagenesis is used. In this study, spores of Asplenium nidus were collected from frond bearing mature sporangia. Spores were cultured in modified 1/2 MS basal medium supplemented with various combinations of 6-Benzylaminopurine (BAP) and Naphtalene Acetic Acid (NAA). Spore cultures were incubated in incubation room at 24 degree C with 16 hours photoperiod (3500 lux). It was found that, the most effective combinations were 1 mg/1 BAP + 0. 1 mg/1 NAA and 2mg/1 BAP + 0. 1 mg/1 NAA. Prothallus was formed after 10 days of cultures and gametophytes were formed 1 month later. These gametophytes were irradiated with Gamma ray at doses of 0, 20, 90, 120, 150 and 180 Gy. From the preliminary result obtained from this study, for generating variations and desired phenotypic expression for Asplenium nidus, recommended doses for in vitro mutagenesis using spores are between 90 Gy to 150 Gy. Gametophytes were subcultured at monthly interval to ensure further development and propagation. Frequent monitoring for any changes in the morphology of the irradiated Asplenium nidus plants were carried out. (Author)

  15. Antimicrobial Activities of Methanol, Ethanol and Supercritical CO2 Extracts of Philippine Piper betle L. on Clinical Isolates of Gram Positive and Gram Negative Bacteria with Transferable Multiple Drug Resistance.

    Directory of Open Access Journals (Sweden)

    Demetrio L Valle

    Full Text Available Piper betle L. has traditionally been used in alternative medicine in different countries for various therapeutic purposes, including as an anti-infective agent. However, studies reported in the literature are mainly on its activities on drug susceptible bacterial strains. This study determined the antimicrobial activities of its ethanol, methanol, and supercritical CO2 extracts on clinical isolates of multiple drug resistant bacteria which have been identified by the Infectious Disease Society of America as among the currently more challenging strains in clinical management. Assay methods included the standard disc diffusion method and the broth microdilution method for the determination of the minimum inhibitory concentration (MIC and the minimum bactericidal concentrations (MBC of the extracts for the test microorganisms. This study revealed the bactericidal activities of all the P. betle leaf crude extracts on methicillin-resistant Staphylococcus aureus (MRSA, vancomycin-resistant Enterococcus (VRE, extended spectrum β-lactamase-producing Enterobacteriaceae, carbapenem-resistant Enterobacteriaceae, and metallo-β-lactamase-producing Pseudomonas aeruginosa and Acinetobacter baumannii, with minimum bactericidal concentrations that ranged from 19μg/ml to 1250 μg/ml. The extracts proved to be more potent against the Gram positive MRSA and VRE than for the Gram negative test bacteria. VRE isolates were more susceptible to all the extracts than the MRSA isolates. Generally, the ethanol extracts proved to be more potent than the methanol extracts and supercritical CO2 extracts as shown by their lower MICs for both the Gram positive and Gram negative MDRs. MTT cytotoxicity assay showed that the highest concentration (100 μg/ml of P. betle ethanol extract tested was not toxic to normal human dermal fibroblasts (HDFn. Data from the study firmly established P. betle as an alternative source of anti-infectives against multiple drug resistant

  16. Antimicrobial Activities of Methanol, Ethanol and Supercritical CO2 Extracts of Philippine Piper betle L. on Clinical Isolates of Gram Positive and Gram Negative Bacteria with Transferable Multiple Drug Resistance.

    Science.gov (United States)

    Valle, Demetrio L; Cabrera, Esperanza C; Puzon, Juliana Janet M; Rivera, Windell L

    2016-01-01

    Piper betle L. has traditionally been used in alternative medicine in different countries for various therapeutic purposes, including as an anti-infective agent. However, studies reported in the literature are mainly on its activities on drug susceptible bacterial strains. This study determined the antimicrobial activities of its ethanol, methanol, and supercritical CO2 extracts on clinical isolates of multiple drug resistant bacteria which have been identified by the Infectious Disease Society of America as among the currently more challenging strains in clinical management. Assay methods included the standard disc diffusion method and the broth microdilution method for the determination of the minimum inhibitory concentration (MIC) and the minimum bactericidal concentrations (MBC) of the extracts for the test microorganisms. This study revealed the bactericidal activities of all the P. betle leaf crude extracts on methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), extended spectrum β-lactamase-producing Enterobacteriaceae, carbapenem-resistant Enterobacteriaceae, and metallo-β-lactamase-producing Pseudomonas aeruginosa and Acinetobacter baumannii, with minimum bactericidal concentrations that ranged from 19μg/ml to 1250 μg/ml. The extracts proved to be more potent against the Gram positive MRSA and VRE than for the Gram negative test bacteria. VRE isolates were more susceptible to all the extracts than the MRSA isolates. Generally, the ethanol extracts proved to be more potent than the methanol extracts and supercritical CO2 extracts as shown by their lower MICs for both the Gram positive and Gram negative MDRs. MTT cytotoxicity assay showed that the highest concentration (100 μg/ml) of P. betle ethanol extract tested was not toxic to normal human dermal fibroblasts (HDFn). Data from the study firmly established P. betle as an alternative source of anti-infectives against multiple drug resistant bacteria.

  17. Crassaminicella profunda gen. nov., sp. nov., an anaerobic marine bacterium isolated from deep-sea sediments.

    Science.gov (United States)

    Lakhal, Raja; Pradel, Nathalie; Postec, Anne; Ollivier, Bernard; Cayol, Jean-Luc; Godfroy, Anne; Fardeau, Marie-Laure; Galés, Grégoire

    2015-09-01

    A novel, anaerobic, chemo-organotrophic bacterium, designated strain Ra1766H(T), was isolated from sediments of the Guaymas basin (Gulf of California, Mexico) taken from a depth of 2002  m. Cells were thin, motile, Gram-stain-positive, flexible rods forming terminal endospores. Strain Ra1766H(T) grew at temperatures of 25-45 °C (optimum 30 °C), pH 6.7-8.1 (optimum 7.5) and in a salinity of 5-60 g l(-1) NaCl (optimum 30 g l(-1)). It was an obligate heterotrophic bacterium fermenting carbohydrates (glucose and mannose) and organic acids (pyruvate and succinate). Casamino acids and amino acids (glutamate, aspartate and glycine) were also fermented. The main end products from glucose fermentation were acetate, butyrate, ethanol, H2 and CO2. Sulfate, sulfite, thiosulfate, elemental sulfur, fumarate, nitrate, nitrite and Fe(III) were not used as terminal electron acceptors. The predominant cellular fatty acids were C14  : 0, C16 : 1ω7, C16 : 1ω7 DMA and C16 : 0. The main polar lipids consisted of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and phospholipids. The G+C content of the genomic DNA was 33.7 mol%. Phylogenetic analysis of the 16S rRNA gene sequence indicated that strain Ra1766H(T) was affiliated to cluster XI of the order Clostridiales, phylum Firmicutes. The closest phylogenetic relative of Ra1766H(T) was Geosporobacter subterraneus (94.2% 16S rRNA gene sequence similarity). On the basis of phylogenetic inference and phenotypic properties, strain Ra1766H(T) ( = DSM 27501(T) = JCM 19377(T)) is proposed to be the type strain of a novel species of a novel genus, named Crassaminicella profunda.

  18. Gram staining with an automatic machine.

    Science.gov (United States)

    Felek, S; Arslan, A

    1999-01-01

    This study was undertaken to develop a new Gram-staining machine controlled by a micro-controller and to investigate the quality of slides that were stained in the machine. The machine was designed and produced by the authors. It uses standard 220 V AC. Staining, washing, and drying periods are controlled by a timer built in the micro-controller. A software was made that contains a certain algorithm and time intervals for the staining mode. One-hundred and forty smears were prepared from Escherichia coli, Staphylococcus aureus, Neisseria sp., blood culture, trypticase soy broth, direct pus and sputum smears for comparison studies. Half of the slides in each group were stained with the machine, the other half by hand and then examined by four different microbiologists. Machine-stained slides had a higher clarity and less debris than the hand-stained slides (p stained slides, some Gram-positive organisms showed poor Gram-positive staining features (p Gram staining with the automatic machine increases the staining quality and helps to decrease the work load in a busy diagnostic laboratory.

  19. Characterization of the surfaceome of the metal-reducing bacterium Desulfotomaculum reducens

    Directory of Open Access Journals (Sweden)

    Elena eDalla Vecchia

    2014-08-01

    Full Text Available Desulfotomaculum reducens strain MI-1 is a Gram-positive, sulfate-reducing bacterium also capable of reducing Fe(III. Metal reduction in Gram-positive bacteria is poorly understood. Here, we investigated Fe(III reduction with lactate, a non-fermentable substrate, as the electron donor. Lactate consumption is concomitant to Fe(III reduction, but does not support significant growth, suggesting that little energy can be conserved from this process and that it may occur fortuitously. D. reducens can reduce both soluble (Fe(III-citrate and insoluble (hydrous ferric oxide, HFO Fe(III. Because physically inaccessible HFO was not reduced, we concluded that reduction requires direct contact under these experimental conditions. This implies the presence of a surface exposed reductase capable of transferring electrons from the cell to the extracellular electron acceptor. With the goal of characterizing the role of surface proteins in D. reducens and of identifying candidate Fe(III reductases, we carried out an investigation of the surface proteome (surfaceome of D. reducens. Cell surface exposed proteins were extracted by trypsin cell shaving or by lysozyme treatment, and analyzed by liquid chromatography-tandem mass spectrometry. This investigation revealed that the surfaceome fulfills many functions, including solute transport, protein export, maturation and hydrolysis, peptidoglycan synthesis and modification, and chemotaxis. Furthermore, a few redox-active proteins were identified. Among these, three are putatively involved in Fe(III reduction, i.e., a membrane-bound hydrogenase 4Fe-4S cluster subunit (Dred_0462, a heterodisulfide reductase subunit A (Dred_0143 and a protein annotated as alkyl hydroperoxide reductase but likely functioning as a thiol-disulfide oxidoreductase (Dred_1533.

  20. Effect of Light-Activated Hypocrellin B on the Growth and Membrane Permeability of Gram-Negative Escherichia coli Cells

    Directory of Open Access Journals (Sweden)

    Yuan Jiang

    2014-01-01

    Full Text Available Aim. To investigate the effect of light-activated hypocrellin B on the growth and membrane permeability of Gram-negative bacteria. Methods. Escherichia coli (E. coli as a model bacterium of Gram-negative bacteria was incubated with various concentrations of hypocrellin B for 60 min and was subsequently irradiated by blue light with wavelength of 470 nm at the dose of 12 J/cm2. Colony forming units were counted and the growth inhibition rate of E. coli cells was calculated after light-activated hypocrellin B. Membrane permeability was measured using flow cytometry and confocal laser scanning microscopy (CLSM with propidium iodide (PI staining. Bacterial morphology was observed using transmission electron microscopy (TEM. Reactive oxygen species in bacterial cells were measured using flow cytometry with DCFH-DA staining. Results. Significant growth inhibition rate of E. coli cells was observed after photodynamic action of hypocrellin B. Remarkable damage to the ultrastructure of E. coli was also observed by TEM. Flow cytometry and CLSM observation showed that light-activated hypocrellin B markedly increased membrane permeability of E. coli. Flow cytometry showed the intracellular ROS increase in E. coli treated by photodynamic action of hypocrellin B. Conclusion. Light-activated hypocrellin B caused intracellular ROS increase and structural damages and inhibited the growth of Gram-negative E. coli cells.

  1. A flow-cytometric gram-staining technique for milk-associated bacteria.

    Science.gov (United States)

    Holm, Claus; Jespersen, Lene

    2003-05-01

    A Gram-staining technique combining staining with two fluorescent stains, Oregon Green-conjugated wheat germ agglutinin (WGA) and hexidium iodide (HI) followed by flow-cytometric detection is described. WGA stains gram-positive bacteria while HI binds to the DNA of all bacteria after permeabilization by EDTA and incubation at 50 degrees C for 15 min. For WGA to bind to gram-positive bacteria, a 3 M potassium chloride solution was found to give the highest fluorescence intensity. A total of 12 strains representing some of the predominant bacterial species in bulk tank milk and mixtures of these were stained and analyzed by flow cytometry. Overall, the staining method showed a clear differentiation between gram-positive and gram-negative bacterial populations. For stationary-stage cultures of seven gram-positive bacteria and five gram-negative bacteria, an average of 99% of the cells were correctly interpreted. The method was only slightly influenced by the growth phase of the bacteria or conditions such as freezing at -18 degrees C for 24 h. For any of these conditions, an average of at least 95% of the cells were correctly interpreted. When stationary-stage cultures were stored at 5 degrees C for 14 days, an average of 86% of the cells were correctly interpreted. The Gram-staining technique was applied to the flow cytometry analysis of bulk tank milk inoculated with Staphylococcus aureus and Escherichia coli. These results demonstrate that the technique is suitable for analyzing milk samples without precultivation.

  2. Facile synthesis of gold nanoparticles on propylamine functionalized SBA-15 and effect of surface functionality of its enhanced bactericidal activity against gram positive bacteria

    International Nuclear Information System (INIS)

    Bhuyan, Diganta; Saikia, Mrinal; Saikia, Lakshi; Gogoi, Animesh; Saikia, Ratul

    2015-01-01

    The facile synthesis of an SBA-15-pr- + NH 3 .Au 0 nano-hybrid material by spontaneous autoreduction of aqueous chloroaurate anions on propylamine functionalized SBA-15 was successfully demonstrated. The as-synthesized SBA-15-pr- + NH 3 .Au 0 nano-hybrid material was well characterized using low and wide angle x-ray diffraction (XRD), N 2 adsorption–desorption isotherms, Fourier transform infrared (FTIR), transmission electron microscopy (TEM), scanning electron microscopy-energy dispersive x-ray spectroscopy (SEM-EDX), x-ray photoelectron spectroscopy (XPS), UV-Visible spectroscopy and atomic absorption spectroscopy (AAS). The activity of the nano-hybrid material as a potent bactericidal agent was successfully tested against Gram positive/negative bacteria viz. Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The colony killing percentage of Gram positive bacteria was found to be higher than Gram negative bacteria due to the stronger electrostatic interaction between the positively-charged amine functionality of SBA-15 and the negatively charged functionality of the bacterial cell wall. (paper)

  3. Syntrophomonas zehnderi sp. nov., an anaerobe that degrades long-chain fatty acids in co-culture with Methanobacterium formicicum.

    Science.gov (United States)

    Sousa, Diana Z; Smidt, Hauke; Alves, M Madalena; Stams, Alfons J M

    2007-03-01

    An anaerobic, mesophilic, syntrophic fatty-acid-oxidizing bacterium, designated strain OL-4(T), was isolated as a co-culture with Methanobacterium formicicum DSM 1535(NT) from an anaerobic expanded granular sludge bed reactor used to treat an oleate-based effluent. Strain OL-4(T) degraded oleate, a mono-unsaturated fatty acid, and straight-chain fatty acids C(4 : 0)-C(18 : 0) in syntrophic association with Methanobacterium formicicum DSM 1535(NT). Even-numbered fatty acids were degraded to acetate and methane whereas odd-numbered fatty acids were degraded to acetate, propionate and methane. Branched-chain fatty acids were not degraded. The bacterium could not grow axenically with any other substrate tested and therefore is considered to be obligately syntrophic. Fumarate, sulfate, thiosulfate, sulfur and nitrate could not serve as electron acceptors for strain OL-4(T) to degrade oleate or butyrate. Cells of strain OL-4(T) were curved rods, formed spores and showed a variable response to Gram staining. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain OL-4(T) was most closely related to the fatty-acid-oxidizing, syntrophic bacterium Syntrophomonas sp. TB-6 (95 % similarity), Syntrophomonas wolfei subsp. wolfei DSM 2245(T) (94 % similarity) and Syntrophomonas erecta DSM 16215(T) (93 % similarity). In addition to this moderate similarity, phenotypic and physiological characteristics, such as obligate syntrophy, spore formation and utilization of a broader substrate range, differentiated strain OL-4(T) from these Syntrophomonas species. Therefore strain OL-4(T) represents a novel species, for which the name Syntrophomonas zehnderi sp. nov. is proposed. The type strain is OL-4(T) (=DSM 17840(T)=JCM 13948(T)).

  4. Maternal parentage influences spore production but not spore pigmentation in the anisogamous and hermaphroditic fungus Neurospora crassa

    DEFF Research Database (Denmark)

    Zimmerman, Kolea; Levitis, Daniel; Pringle, Anne

    2014-01-01

    . In this fungus, pigmented spores are viable and unpigmented spores are inviable. These results show that while both parents influence all these traits, maternal influence is strongest on both fertility and mortality traits until the spores are physiologically independent of the maternal cytoplasm.......In this study, we tested the hypothesis that maternal effects on offspring production and quality are greater than paternal effects in both offspring number (fertility) and offspring viability (mortality). We used the model filamentous fungus Neurospora crassa. This fungus is anisogamous......, and various ascospore characteristics. Mixed effects models of these data show that the female parent accounts for the majority of variation in perithecial production, number of spores produced, and spore germination. Surprisingly, both sexes equally influence the percentage of spores that are pigmented...

  5. Burkholderia jiangsuensis sp. nov., a methyl parathion degrading bacterium, isolated from methyl parathion contaminated soil.

    Science.gov (United States)

    Liu, Xu-Yun; Li, Chun-Xiu; Luo, Xiao-Jing; Lai, Qi-Liang; Xu, Jian-He

    2014-09-01

    A methyl parathion (MP) degrading bacterial strain, designated MP-1(T), was isolated from a waste land where pesticides were formerly manufactured in Jiangsu province, China. Polyphasic taxonomic studies showed that MP-1(T) is a Gram-stain-negative, non-spore-forming, rod-shaped and motile bacterium. The bacterium could grow at salinities of 0-1 % (w/v) and temperatures of 15-40 °C. Strain MP-1(T) could reduce nitrate to nitrite, utilize d-glucose and l-arabinose, but not produce indole, or hydrolyse gelatin. Phylogenetic analysis based on 16S rRNA gene sequences demonstrated that MP-1(T) belongs to the genus Burkholderia, showing highest sequence similarity to Burkholderia grimmiae DSM 25160(T) (98.5 %), and similar strains including Burkholderia zhejiangensis OP-1(T) (98.2 %), Burkholderia choica LMG 22940(T) (97.5 %), Burkholderia glathei DSM 50014(T) (97.4 %), Burkholderia terrestris LMG 22937(T) (97.2 %) and Burkholderia telluris LMG 22936(T) (97.0 %). In addition, the gyrB and recA gene segments of strain MP-1(T) exhibited less than 89.0 % and 95.1 % similarities with the most highly-related type strains indicated above. The G+C content of strain MP-1(T) was 62.6 mol%. The major isoprenoid quinone was ubiquinone Q-8. The predominant polar lipids comprised phosphatidyl ethanolamine, phosphatidyl glycerol, aminolipid and phospholipid. The principal fatty acids in strain MP-1(T) were C18 : 1ω7c/C18 : 1ω6c (23.3 %), C16 : 0 (16.8 %), cyclo-C17 : 0 (15.0 %), C16 : 1ω7c/C16 : 1ω6 (8.5 %), cyclo-C19 : 0ω8c (8.1 %), C16 : 1 iso I/C14 : 0 3-OH (5.7 %), C16 : 0 3-OH (5.6 %) and C16 : 02-OH (5.1 %). The DNA-DNA relatedness values between strain MP-1(T) and the three type strains (B. grimmiae DSM 25160(T), B. zhejiangensis OP-1(T) and B. glathei DSM 50014(T)) ranged from 24.6 % to 37.4 %. In accordance with phenotypic and genotypic characteristics, strain MP-1(T) represents a novel

  6. Biosynthesis of gold nanoparticles by the extreme bacterium Deinococcus radiodurans and an evaluation of their antibacterial properties.

    Science.gov (United States)

    Li, Jiulong; Li, Qinghao; Ma, Xiaoqiong; Tian, Bing; Li, Tao; Yu, Jiangliu; Dai, Shang; Weng, Yulan; Hua, Yuejin

    Deinococcus radiodurans is an extreme bacterium known for its high resistance to stresses including radiation and oxidants. The ability of D. radiodurans to reduce Au(III) and biosynthesize gold nanoparticles (AuNPs) was investigated in aqueous solution by ultraviolet and visible (UV/Vis) absorption spectroscopy, electron microscopy, X-ray diffraction (XRD), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). D. radiodurans efficiently synthesized AuNPs from 1 mM Au(III) solution in 8 h. The AuNPs were of spherical, triangular and irregular shapes with an average size of 43.75 nm and a polydispersity index of 0.23 as measured by DLS. AuNPs were distributed in the cell envelope, across the cytosol and in the extracellular space. XRD analysis confirmed the crystallite nature of the AuNPs from the cell supernatant. Data from the FTIR and XPS showed that upon binding to proteins or compounds through interactions with carboxyl, amine, phospho and hydroxyl groups, Au(III) may be reduced to Au(I), and further reduced to Au(0) with the capping groups to stabilize the AuNPs. Biosynthesis of AuNPs was optimized with respect to the initial concentration of gold salt, bacterial growth period, solution pH and temperature. The purified AuNPs exhibited significant antibacterial activity against both Gram-negative ( Escherichia coli ) and Gram-positive ( Staphylococcus aureus ) bacteria by damaging their cytoplasmic membrane. Therefore, the extreme bacterium D. radiodurans can be used as a novel bacterial candidate for efficient biosynthesis of AuNPs, which exhibited potential in biomedical application as an antibacterial agent.

  7. A fluorescence in situ staining method for investigating spores and vegetative cells of Clostridia by confocal laser scanning microscopy and structured illuminated microscopy.

    Science.gov (United States)

    D'Incecco, P; Ong, L; Gras, S; Pellegrino, L

    2018-04-18

    Non-pathogenic spore-forming Clostridia are of increasing interest due to their application in biogas production and their capability to spoil different food products. The life cycle for Clostridium includes a spore stage that can assist in survival under environmentally stressful conditions, such as extremes of temperature or pH. Due to their size, spores can be investigated by a range of microscopic techniques, many of which involve sample pre-treatment. We have developed a quick, simple and non-destructive fluorescent staining procedure that allows a clear differentiation between spores and vegetative cells and effectively stains spores, allowing recovery and tracking in subsequent experiments. Hoechst 34580, Propidium iodide and wheat germ agglutinin WGA 488 were used in combination to stain four strains of Clostridia at different life cycle stages. Staining was conducted without drying the sample, preventing changes induced by dehydration and cells observed by confocal laser scanner microscopy or using a super-resolution microscope equipped with a 3D-structured illumination module. Dual staining with Hoechst/Propidium iodide differentiated spores from vegetative cells, provided information on the viability of cells and was successfully applied to follow spore production induced by heating. Super-resolution microscopy of spores probed by Hoechst 34580 also allowed chromatin to be visualised. Direct staining of a cheese specimen using Nile Red and Fast Green allowed in situ observation of spores within the cheese and their position within the cheese matrix. The proposed staining method has broad applicability and can potentially be applied to follow Clostridium spore behaviour in a range of different environments. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Spatial and temporal distribution of Alternaria spores in the Iberian Peninsula atmosphere, and meteorological relationships: 1993-2009.

    Science.gov (United States)

    Aira, María-Jesús; Rodríguez-Rajo, Francisco-Javier; Fernández-González, María; Seijo, Carmen; Elvira-Rendueles, Belén; Abreu, Ilda; Gutiérrez-Bustillo, Montserrat; Pérez-Sánchez, Elena; Oliveira, Manuela; Recio, Marta; Tormo, Rafael; Morales, Julia

    2013-03-01

    This paper provides an updated of airborne Alternaria spore spatial and temporal distribution patterns in the Iberian Peninsula, using a common non-viable volumetric sampling method. The highest mean annual spore counts were recorded in Sevilla (39,418 spores), Mérida (33,744) and Málaga (12,947), while other sampling stations never exceeded 5,000. The same cities also recorded the highest mean daily spore counts (Sevilla 109 spores m(-3); Mérida 53 spores m(-3) and Málaga 35 spores m(-3)) and the highest number of days on which counts exceeded the threshold levels required to trigger allergy symptoms (Sevilla 38 % and Mérida 30 % of days). Analysis of annual spore distribution patterns revealed either one or two peaks, depending on the location and prevailing climate of sampling stations. For all stations, average temperature was the weather parameter displaying the strongest positive correlation with airborne spore counts, whilst negative correlations were found for rainfall and relative humidity.

  9. Effects of steam autoclave treatment on Geobacillus stearothermophilus spores.

    Science.gov (United States)

    Huesca-Espitia, L C; Suvira, M; Rosenbeck, K; Korza, G; Setlow, B; Li, W; Wang, S; Li, Y-Q; Setlow, P

    2016-11-01

    To determine the mechanism of autoclave killing of Geobacillus stearothermophilus spores used in biological indicators (BIs) for steam autoclave sterilization, and rates of loss of spore viability and a spore enzyme used in BIs. Spore viability, dipicolinic acid (DPA) release, nucleic acid staining, α-glucosidase activity, protein structure and mutagenesis were measured during autoclaving of G. stearothermophilus spores. Loss of DPA and increases in spore core nucleic acid staining were slower than loss of spore viability. Spore core α-glucosidase was also lost more slowly than spore viability, although soluble α-glucosidase in spore preparations was lost more rapidly. However, spores exposed to an effective autoclave sterilization lost all viability and α-glucosidase activity. Apparently killed autoclaved spores were not recovered by artificial germination in supportive media, much spore protein was denatured during autoclaving, and partially killed autoclave-treated spore preparations did not acquire mutations. These results indicate that autoclave-killed spores cannot be revived, spore killing by autoclaving is likely by protein damage, and spore core α-glucosidase activity is lost more slowly than spore viability. This work provides insight into the mechanism of autoclave killing of spores of an organism used in BIs, and that a spore enzyme in a BI is more stable to autoclaving than spore viability. © 2016 The Society for Applied Microbiology.

  10. Marinobacter lacisalsi sp. nov., a moderately halophilic bacterium isolated from the saline-wetland wildfowl reserve Fuente de Piedra in southern Spain.

    Science.gov (United States)

    Aguilera, Margarita; Jiménez-Pranteda, Maria L; Kharroub, Karima; González-Paredes, Ana; Durban, Juan J; Russell, Nick J; Ramos-Cormenzana, Alberto; Monteoliva-Sánchez, Mercedes

    2009-07-01

    A Gram-negative, non-spore-forming, motile, moderately halophilic, aerobic, rod-shaped bacterium, designated strain FP2.5(T), was isolated from the inland hypersaline lake Fuente de Piedra, a saline-wetland wildfowl reserve located in the province of Málaga in southern Spain. Strain FP2.5(T) was subjected to a polyphasic taxonomic study. It produced colonies with a light-yellow pigment. Strain FP2.5(T) grew at salinities of 3-15 % (w/v) and at temperatures of 20-40 degrees C. The pH range for growth was 5-9. Strain FP2.5(T) was able to utilize various organic acids as sole carbon and energy source. Its major fatty acids were C(16 : 0), C(18 : 1)omega9c and C(16 : 1)omega9c. The DNA G+C content was 58.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain FP2.5(T) appeared to be a member of the genus Marinobacter and clustered closely with the type strains of Marinobacter segnicrescens, Marinobacter bryozoorum and Marinobacter gudaonensis (levels of 16S rRNA gene sequence similarity of 98.1, 97.4 and 97.2 %, respectively). However, DNA-DNA relatedness between the new isolate and the type strains of its closest related Marinobacter species was low; levels of DNA-DNA relatedness between strain FP2.5(T) and M. segnicrescens LMG 23928(T), M. bryozoorum DSM 15401(T) and M. gudaonensis DSM 18066(T) were 36.3, 32.1 and 24.9 %, respectively. On the basis of phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness data, strain FP2.5(T) is considered to represent a novel species of the genus Marinobacter, for which the name Marinobacter lacisalsi sp. nov. is proposed. The type strain is FP2.5(T) (=CECT 7297(T)=LMG 24237(T)).

  11. Burdock (Arctium lappa Leaf Extracts Increase the In Vitro Antimicrobial Efficacy of Common Antibiotics on Gram-positive and Gram-negative Bacteria

    Directory of Open Access Journals (Sweden)

    Pirvu Lucia

    2017-04-01

    Full Text Available This work aimed to study the potential effects of four Arctii folium extracts, 5 mg gallic [GAE] acid equivalents per 1 mL sample, on six antibiotics (Ampicillin/AM, Tetracycline/TE, Ciprofloxacin/CIP, Sulfamethoxazole-Trimethoprim/SXT, Chloramphenicol/C and Gentamicin/CN tested on four Gram-positive (Staphylococcus aureus ATCC 6538, Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, and Staphylococcus epidermidis ATCC 12228 and five Gram-negative (Proteus mirabilis ATCC 29245, Escherichia coli ATCC 35218, E. coli ATCC 11229, E. coli ATCC 8739, and Bacillus cereus ATCC 11778 bacteria. Arctii folium extracts were the whole ethanol extract/W and subsequent ethyl acetate/EA, aqueous/AQ, and chloroform/CHL fractions. Chemical qualitative analysis (HPTLC method emphasized five main polyphenol compounds in Arctii folium polar extracts: chlorogenic acid (Rf≈0.52/0.55 and its isomer, 1,5-di-O-caffeoylquinic acid (Rf≈0.90/0.92, plus cynarin (Rf≈0.77, hyperoside (Rf≈0.68/0.64 and isoquercitrin (Rf≈0.69/0.71. Microbiological screening indicated Arctii folium polar extracts (AQ and W efficacy on S. epidermidis ATCC 12228; the MIC values were in the range of common antibiotics, being 32 and 128 μg GAE per mL sample respectively. The unpredictable effects (stimulatory or inhibitory of Arctii folium extracts in combination with typical antibiotics as well as a potential use of the whole ethanol extract/W for restoring the antimicrobial potency of susceptible antibiotics have also been evidenced.

  12. Novel Antimicrobial Peptides That Inhibit Gram Positive Bacterial Exotoxin Synthesis

    Science.gov (United States)

    Merriman, Joseph A.; Nemeth, Kimberly A.; Schlievert, Patrick M.

    2014-01-01

    Gram-positive bacteria, such as Staphylococcus aureus, cause serious human illnesses through combinations of surface virulence factors and secretion of exotoxins. Our prior studies using the protein synthesis inhibitor clindamycin and signal transduction inhibitors glycerol monolaurate and α-globin and β-globin chains of hemoglobin indicate that their abilities to inhibit exotoxin production by S. aureus are separable from abilities to inhibit growth of the organism. Additionally, our previous studies suggest that inhibition of exotoxin production, in absence of ability to kill S. aureus and normal flora lactobacilli, will prevent colonization by pathogenic S. aureus, while not interfering with lactobacilli colonization. These disparate activities may be important in development of novel anti-infective agents that do not alter normal flora. We initiated studies to explore the exotoxin-synthesis-inhibition activity of hemoglobin peptides further to develop potential agents to prevent S. aureus infections. We tested synthesized α-globin chain peptides, synthetic variants of α-globin chain peptides, and two human defensins for ability to inhibit exotoxin production without significantly inhibiting S. aureus growth. All of these peptides were weakly or not inhibitory to bacterial growth. However, the peptides were inhibitory to exotoxin production with increasing activity dependent on increasing numbers of positively-charged amino acids. Additionally, the peptides could be immobilized on agarose beads or have amino acid sequences scrambled and still retain exotoxin-synthesis-inhibition. The peptides are not toxic to human vaginal epithelial cells and do not inhibit growth of normal flora L. crispatus. These peptides may interfere with plasma membrane signal transduction in S. aureus due to their positive charges. PMID:24748386

  13. Nitrous oxide emission by the non-denitrifying, nitrate ammonifier Bacillus licheniformis

    OpenAIRE

    Sun, Yihua; De Vos, Paul; Heylen, Kim

    2016-01-01

    Background Firmicutes have the capacity to remove excess nitrate from the environment via either denitrification, dissimilatory nitrate reduction to ammonium or both. The recent renewed interest in their nitrogen metabolism has revealed many interesting features, the most striking being their wide variety of dissimilatory nitrate reduction pathways. In the present study, nitrous oxide production from Bacillus licheniformis, a ubiquitous Gram-positive, spore-forming species with many industria...

  14. Virgibacillus ainsalahensis sp. nov., a Moderately Halophilic Bacterium Isolated from Sediment of a Saline Lake in South of Algeria.

    Science.gov (United States)

    Amziane, Meriam; Darenfed-Bouanane, Amel; Abderrahmani, Ahmed; Selama, Okba; Jouadi, Lydia; Cayol, Jean-Luc; Nateche, Farida; Fardeau, Marie-Laure

    2017-02-01

    A Gram-positive, moderately halophilic, endospore-forming bacterium, designated MerV T , was isolated from a sediment sample of a saline lake located in Ain Salah, south of Algeria. The cells were rod shaped and motile. Isolate MerV T grew at salinity interval of 0.5-25% NaCl (optimum, 5-10%), pH 6.0-12.0 (optimum, 8.0), and temperature between 10 and 40 °C (optimum, 30 °C).The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, a glycolipid, a phospholipid, and two lipids, and MK-7 is the predominant menaquinone. The predominant cellular fatty acids were anteiso C 15:0 and anteiso C 17:0 . The DNA G+C content was 45.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain MerV T was most closely related to Virgibacillus halodenitrificans (gene sequence similarity of 97.0%). On the basis of phenotypic, chemotaxonomic properties, and phylogenetic analyses, strain MerV T (=DSM = 28944 T ) should be placed in the genus Virgibacillus as a novel species, for which the name Virgibacillus ainsalahensis is proposed.

  15. Is the gram stain useful in the microbiologic diagnosis of VAP? A meta-analysis.

    Science.gov (United States)

    O'Horo, John C; Thompson, Deb; Safdar, Nasia

    2012-08-01

    In a meta-analysis examining respiratory specimen Gram stain for diagnosis of ventilator-associated pneumonia, absence of bacteria on Gram stain had a high negative predictive value, but a positive Gram stain correlated poorly with organisms recovered in culture. Rapid and accurate diagnosis of ventilator-associated pneumonia (VAP) is a major challenge and no generally accepted gold standard exists for VAP diagnosis. We conducted a meta-analysis to examine the role of respiratory specimen Gram stain to diagnose VAP, and the correlation with final culture results. In 21 studies, pooled sensitivity of Gram stain for VAP was 0.79 (95% confidence interval [CI], .77-0.81; P Gram stain for a VAP prevalence of 20%-30% was 91%, suggesting that VAP is unlikely with a negative Gram stain but the positive predictive value of Gram stain was only 40%. Pooled kappa was 0.42 for gram-positive organisms and 0.34 for gram-negative organisms, suggesting fair concordance between organisms on Gram stain and recovery by culture. Therefore, a positive Gram stain should not be used to narrow anti-infective therapy until culture results become available.

  16. Cell envelope stress response in cell wall-deficient L-forms of Bacillus subtilis.

    Science.gov (United States)

    Wolf, Diana; Domínguez-Cuevas, Patricia; Daniel, Richard A; Mascher, Thorsten

    2012-11-01

    L-forms are cell wall-deficient bacteria that can grow and proliferate in osmotically stabilizing media. Recently, a strain of the Gram-positive model bacterium Bacillus subtilis was constructed that allowed controlled switching between rod-shaped wild-type cells and corresponding L-forms. Both states can be stably maintained under suitable culture conditions. Because of the absence of a cell wall, L-forms are known to be insensitive to β-lactam antibiotics, but reports on the susceptibility of L-forms to other antibiotics that interfere with membrane-anchored steps of cell wall biosynthesis are sparse, conflicting, and strongly influenced by strain background and method of L-form generation. Here we investigated the response of B. subtilis to the presence of cell envelope antibiotics, with regard to both antibiotic resistance and the induction of the known LiaRS- and BceRS-dependent cell envelope stress biosensors. Our results show that B. subtilis L-forms are resistant to antibiotics that interfere with the bactoprenol cycle, such as bacitracin, vancomycin, and mersacidin, but are hypersensitive to nisin and daptomycin, which both affect membrane integrity. Moreover, we established a lacZ-based reporter gene assay for L-forms and provide evidence that LiaRS senses its inducers indirectly (damage sensing), while the Bce module detects its inducers directly (drug sensing).

  17. Feasibility of flotation concentration of fungal spores as a method to identify toxigenic mushrooms

    Directory of Open Access Journals (Sweden)

    Bazzle LJ

    2014-12-01

    97.5% of trials. The most common spore shapes observed were globose, spiked, elliptical, smooth and reticulate. Conclusion: Flotation can concentrate mushroom spores; however, false negative results can occur. Spore morphology could not be used to differentiate species of mushroom-forming fungi since the spore shape and surface characteristics seen in the present study were often observed with multiple species of mushroom-forming fungi. Keywords: gastrointestinal contents, mushroom spore identification, mushroom toxicity, Amanita spp.

  18. The Role of Functional Amyloids in Multicellular Growth and Development of Gram-Positive Bacteria

    DEFF Research Database (Denmark)

    Dragoš, Anna; Kovács, Ákos T.; Claessen, Dennis

    2017-01-01

    Amyloid fibrils play pivotal roles in all domains of life. In bacteria, these fibrillar structures are often part of an extracellular matrix that surrounds the producing organism and thereby provides protection to harsh environmental conditions. Here, we discuss the role of amyloid fibrils...... in the two distant Gram-positive bacteria, Streptomyces coelicolor and Bacillus subtilis. We describe how amyloid fibrils contribute to a multitude of developmental processes in each of these systems, including multicellular growth and community development. Despite this variety of tasks, we know...... surprisingly little about how their assembly is organized to fulfill all these roles....

  19. Elemental sulfur and thiosulfate disproportionation by Desulfocapsa sulfoexigens sp. nov., a new anaerobic bacterium isolated from marine surface sediment

    DEFF Research Database (Denmark)

    Finster, Kai; Liesack, Werner; Thamdrup, Bo

    1998-01-01

    A mesophilic, anaerobic, gram-negative bacterium, strain SB164P1, was enriched and isolated from oxidized marine surface sediment with elemental sulfur as the sole energy substrate in the presence of ferrihydrite. Elemental sulfur was disproportionated to hydrogen sulfide and sulfate. Growth was ...

  20. Sporangium Exposure and Spore Release in the Peruvian Maidenhair Fern (Adiantum peruvianum, Pteridaceae.

    Directory of Open Access Journals (Sweden)

    Simon Poppinga

    Full Text Available We investigated the different processes involved in spore liberation in the polypod fern Adiantum peruvianum (Pteridaceae. Sporangia are being produced on the undersides of so-called false indusia, which are situated at the abaxial surface of the pinnule margins, and become exposed by a desiccation-induced movement of these pinnule flaps. The complex folding kinematics and functional morphology of false indusia are being described, and we discuss scenarios of movement initiation and passive hydraulic actuation of these structures. High-speed cinematography allowed for analyses of fast sporangium motion and for tracking ejected spores. Separation and liberation of spores from the sporangia are induced by relaxation of the annulus (the 'throwing arm' of the sporangium catapult and conservation of momentum generated during this process, which leads to sporangium bouncing. The ultra-lightweight spores travel through air with a maximum velocity of ~5 m s(-1, and a launch acceleration of ~6300 g is measured. In some cases, the whole sporangium, or parts of it, together with contained spores break away from the false indusium and are shed as a whole. Also, spores can stick together and form spore clumps. Both findings are discussed in the context of wind dispersal.