2024-03-28T14:07:06Zhttp://repository.helmholtz-hzi.de/oai/requestoai:repository.helmholtz-hzi.de:10033/150932019-08-30T11:26:42Zcom_10033_620652col_10033_620675
Vasilyeva, Lina V
Omelchenko, Marina V
Berestovskaya, Yulia Y
Lysenko, Anatolii M
Abraham, Wolf-Rainer
Dedysh, Svetlana N
Zavarzin, George A
2007-12-10T12:57:02Z
2007-12-10T12:57:02Z
2006-09
Asticcacaulis benevestitus sp. nov., a psychrotolerant, dimorphic, prosthecate bacterium from tundra wetland soil. 2006, 56 (Pt 9):2083-8 Int. J. Syst. Evol. Microbiol.
1466-5026
16957103
10.1099/ijs.0.64122-0
http://hdl.handle.net/10033/15093
International journal of systematic and evolutionary microbiology
A Gram-negative, aerobic, heterotrophic, non-pigmented, dimorphic prosthecate bacterium was isolated from tundra wetland soil and designated strain Z-0023(T). Cells of this strain had a dimorphic life cycle and developed a non-adhesive stalk at a site not coincident with the centre of the cell pole, a characteristic typical of representatives of the genus Asticcacaulis. A highly distinctive feature of cells of strain Z-0023(T) was the presence of a conical, bell-shaped sheath when grown at low temperature. This prosthecate bacterium was a psychrotolerant, moderately acidophilic organism capable of growth between 4 and 28 degrees Celsius (optimum 15-20 degrees Celsius) and between pH 4.5 and 8.0 (optimum 5.6-6.0). The major phospholipid fatty acid was 18 : 1omega7c and the major phospholipids were phosphatidylglycerols. The G+C content of the DNA was 60.4 mol%. On the basis of 16S rRNA gene sequence similarity, strain Z-0023(T) was most closely related to Asticcacaulis biprosthecium (98 % similarity), Asticcacaulis taihuensis (98 %) and Asticcacaulis excentricus (95 %). However, low levels of DNA-DNA relatedness to these organisms and a number of distinctive features of the tundra wetland isolate indicated that it represented a novel species of the genus Asticcacaulis, for which the name Asticcacaulis benevestitus sp. nov. is proposed. The type strain is Z-0023(T) (=DSM 16100(T)=ATCC BAA-896(T)).
en
Asticcacaulis benevestitus sp. nov., a psychrotolerant, dimorphic, prosthecate bacterium from tundra wetland soil.
Article
oai:repository.helmholtz-hzi.de:10033/161922019-08-30T11:32:13Zcom_10033_620652col_10033_620675
Macedo, A.J.
Neu, T. R.
Kuhlicke, U.
Abraham, Wolf-Rainer
2008-01-16T14:09:49Z
2008-01-16T14:09:49Z
2006
14790505
14790513
10.1017/S1479050507002116
http://hdl.handle.net/10033/16192
Biofilms
null
Adaptation of microbial communities in soil contaminated with polychlorinated biphenyls, leading to the transformation of more highly chlorinated congeners in biofilm communities
Article
oai:repository.helmholtz-hzi.de:10033/197772019-08-30T11:26:13Zcom_10033_620652col_10033_620675
Wittich, Rolf-Michael
Busse, Hans-Jürgen
Kämpfer, Peter
Tiirola, Marja
Wieser, Monika
Macedo, Alexandre J
Abraham, Wolf-Rainer
2008-03-05T12:34:37Z
2008-03-05T12:34:37Z
2007-02
Sphingobium aromaticiconvertens sp. nov., a xenobiotic-compound-degrading bacterium from polluted river sediment. 2007, 57 (Pt 2):306-10 Int. J. Syst. Evol. Microbiol.
1466-5026
17267969
10.1099/ijs.0.64433-0
http://hdl.handle.net/10033/19777
International journal of systematic and evolutionary microbiology
A bacterial strain capable of degrading some monochlorinated dibenzofurans, designated RW16T, was isolated from aerobic River Elbe sediments. The strain was characterized based on 16S rRNA gene sequence analysis, DNA G+C content, physiological characteristics, polyamines, ubiquinone and polar lipid pattern and fatty acid composition. This analysis revealed that strain RW16T represents a novel species of the genus Sphingobium. The DNA G+C content of strain RW16T, 60.7 mol%, is the lowest yet reported for the genus. 16S rRNA gene sequence analysis placed strain RW16T as an outlier in the genus Sphingobium. The name Sphingobium aromaticiconvertens sp. nov. is proposed for this dibenzofuran-mineralizing organism, with type strain RW16T (=DSM 12677T=CIP 109198T).
en
Sphingobium aromaticiconvertens sp. nov., a xenobiotic-compound-degrading bacterium from polluted river sediment.
Article
oai:repository.helmholtz-hzi.de:10033/198142019-08-30T11:26:13Zcom_10033_620652col_10033_620675
Lu, Yahai
Abraham, Wolf-Rainer
Conrad, Ralf
2008-03-05T12:50:08Z
2008-03-05T12:50:08Z
2007-02
Spatial variation of active microbiota in the rice rhizosphere revealed by in situ stable isotope probing of phospholipid fatty acids. 2007, 9 (2):474-81 Environ. Microbiol.
1462-2912
17222145
10.1111/j.1462-2920.2006.01164.x
http://hdl.handle.net/10033/19814
Environmental microbiology
This report is part of a serial study applying stable isotope labelling to rice microcosms to track the utilization of recently photosynthesized carbon by active microbiota in the rhizosphere. The objective of the present study was to apply phospholipid fatty acid-based stable isotope probing (PLFA-SIP) to detect the spatial variation of active microorganisms associated with rhizosphere carbon flow. In total, 49 pulses of 13CO2 were applied to rice plants in a microcosm over a period of 7 days. Rhizosphere soil was separated from bulk soil by a root bag. Soil samples were taken from rhizosphere and bulk soil, and the bulk soil samples were further partitioned both vertically (up layer and down layer) and horizontally with increasing distance to the root bag. Incorporation of 13C into PLFAs sharply decreased with distance to the roots. The labelling of 16:1omega9, 18:1omega7, 18:1omega9, 18:2omega6,9 and i14:0 PLFAs was relatively stronger in the rhizosphere while that of i15:0 and i17:0 increased in the bulk soil. The microorganisms associated with 16:1omega9 were active in both up- and down-layer soils. The microorganisms represented by i14:0, 18:1omega7 and 18:2omega6,9 exhibited a relatively higher activity in up-layer soil, whereas those represented by i15:0 and i17:0 were more active in down-layer soil. These results suggest that in the rhizosphere Gram-negative and eukaryotic microorganisms were most actively assimilating root-derived C, whereas Gram-positive microorganisms became relatively more important in the bulk soil. The active populations apparently differed between up- and down-layer soil and in particular changed with distance to the roots, demonstrating systematic changes in the activity of the soil microbiota surrounding roots.
en
Spatial variation of active microbiota in the rice rhizosphere revealed by in situ stable isotope probing of phospholipid fatty acids.
Article
oai:repository.helmholtz-hzi.de:10033/239522019-08-30T11:28:24Zcom_10033_620652col_10033_620675
Shrestha, Minita
Abraham, Wolf-Rainer
Shrestha, Pravin Malla
Noll, Matthias
Conrad, Ralf
2008-04-22T09:10:50Z
2008-04-22T09:10:50Z
2008-02
Activity and composition of methanotrophic bacterial communities in planted rice soil studied by flux measurements, analyses of pmoA gene and stable isotope probing of phospholipid fatty acids. 2008, 10 (2):400-12 Environ. Microbiol.
1462-2920
18177369
10.1111/j.1462-2920.2007.01462.x
http://hdl.handle.net/10033/23952
Environmental microbiology
Methanotrophs in the rhizosphere of rice field ecosystems attenuate the emissions of CH(4) into the atmosphere and thus play an important role for the global cycle of this greenhouse gas. Therefore, we measured the activity and composition of the methanotrophic community in the rhizosphere of rice microcosms. Methane oxidation was determined by measuring the CH(4) flux in the presence and absence of difluoromethane as a specific inhibitor for methane oxidation. Methane oxidation started on day 24 and reached the maximum on day 32 after transplantation. The total methanotrophic community was analysed by terminal restriction fragment length polymorphism (T-RFLP) and cloning/sequencing of the pmoA gene, which encodes a subunit of particulate methane monooxygenase. The metabolically active methanotrophic community was analysed by stable isotope probing of microbial phospholipid fatty acids (PLFA-SIP) using (13)C-labelled CH(4) directly added to the rhizospheric region. Rhizospheric soil and root samples were collected after exposure to (13)CH(4) for 8 and 18 days. Both T-RFLP/cloning and PLFA-SIP approaches showed that type I and type II methanotrophic populations changed over time with respect to activity and population size in the rhizospheric soil and on the rice roots. However, type I methanotrophs were more active than type II methanotrophs at both time points indicating they were of particular importance in the rhizosphere. PLFA-SIP showed that the active methanotrophic populations exhibit a pronounced spatial and temporal variation in rice microcosms.
en
Activity and composition of methanotrophic bacterial communities in planted rice soil studied by flux measurements, analyses of pmoA gene and stable isotope probing of phospholipid fatty acids.
Article
oai:repository.helmholtz-hzi.de:10033/247122019-08-30T11:28:51Zcom_10033_620652col_10033_620675
Wittich, Rolf-Michael
Busse, Hans-Jürgen
Kämpfer, Peter
Macedo, Alexandre J
Tiirola, Marja
Wieser, Monika
Abraham, Wolf-Rainer
2008-05-02T13:10:52Z
2008-05-02T13:10:52Z
2007-08
Sphingomonas fennica sp. nov. and Sphingomonas haloaromaticamans sp. nov., outliers of the genus Sphingomonas. 2007, 57 (Pt 8):1740-6 Int. J. Syst. Evol. Microbiol.
1466-5026
17684248
10.1099/ijs.0.64835-0
http://hdl.handle.net/10033/24712
International journal of systematic and evolutionary microbiology
Bacterial isolates obtained from polychlorophenol-contaminated sites in Finland (strain K101(T)) and from a Dutch drinking water well (strain A175(T)) were characterized taxonomically. 16S rRNA gene sequence analysis, determination of DNA G+C content, physiological characterization, estimation of the ubiquinone and polar lipid patterns and fatty acid content revealed that strains K101(T) and A175(T) were similar to Sphingomonas wittichii RW1(T) but also showed pronounced differences. The DNA G+C contents of the two novel strains were 63.6 and 66.1 mol%, respectively. On the basis of these results, two novel species of the genus Sphingomonas are described, for which the names Sphingomonas haloaromaticamans sp. nov. [type strain A175(T) (=DSM 13477(T)=CCUG 53463(T))] and Sphingomonas fennica sp. nov. [type strain K101(T) (=DSM 13665(T)=CCUG 53462(T))] are proposed.
en
Sphingomonas fennica sp. nov. and Sphingomonas haloaromaticamans sp. nov., outliers of the genus Sphingomonas.
Article
oai:repository.helmholtz-hzi.de:10033/361722019-08-30T11:33:57Zcom_10033_620652col_10033_620675
Pawelczyk, Sonja
Abraham, Wolf-Rainer
Harms, Hauke
Müller, Susann
2008-08-21T12:39:01Z
2008-08-21T12:39:01Z
2008-09
Community-based degradation of 4-chorosalicylate tracked on the single cell level. 2008, 75 (1):117-26 J. Microbiol. Methods
0167-7012
18593643
10.1016/j.mimet.2008.05.018
http://hdl.handle.net/10033/36172
Journal of microbiological methods
4-Chlorosalicylate (4-CS) can be degraded completely by a bacterial consortium consisting of Pseudomonas reinekei (MT1), Achromobacter spanius (MT3) and Pseudomonas veronii (MT4). The fourth species Wautersiella falsenii (MT2) is thought to act as a 'necrotizer' of the community. Single cell approaches were used to follow every species' degradation activity within the community by assuming that growth and proliferation are activity markers for the utilization of 4-CS and its degradation pathway intermediates as carbon and energy sources. A primary/secondary antibody staining technique for species differentiation was applied and a species-resolved determination of proliferation activity by flow cytometry undertaken. Degradation was followed by quantifying 4-CS and the resulting intermediates by HPLC. A good correlation of HPLC bulk data with the proliferation activity states of every species within the community was found. It was also assumed that reduced activity of strain MT4 and increased proliferation of strain MT2 might have caused an observed breakdown of the consortium grown in the bioreactor. The double staining technique provided the chance to follow bacterial cell states and their roles in mixed cultures without applying labelled substrates. It is therefore in line with single cell techniques already successfully applied in biotechnology for developing strategies to optimize microbially catalyzed production processes.
en
Community-based degradation of 4-chorosalicylate tracked on the single cell level.
Article
oai:repository.helmholtz-hzi.de:10033/376522019-08-30T11:26:13Zcom_10033_620652col_10033_620675
Abraham, Wolf-Rainer
Macedo, Alexandre J
Lünsdorf, Heinrich
Fischer, Roman
Pawelczyk, Sonja
Smit, John
Vancanneyt, Marc
2008-09-11T09:26:53Z
2008-09-11T09:26:53Z
2008-08
Phylogeny by a polyphasic approach of the order Caulobacterales, proposal of Caulobacter mirabilis sp. nov., Phenylobacterium haematophilum sp. nov. and Phenylobacterium conjunctum sp. nov., and emendation of the genus Phenylobacterium. 2008, 58 (Pt 8):1939-49 Int. J. Syst. Evol. Microbiol.
1466-5026
18676485
10.1099/ijs.0.65567-0
http://hdl.handle.net/10033/37652
International journal of systematic and evolutionary microbiology
Three strains of Gram-negative, rod-shaped, non-spore-forming bacteria were isolated from fresh water and human blood. As determined by analyses of 16S rRNA gene sequences, the prosthecate strain FWC 38T was affiliated to the alphaproteobacterial genus Caulobacter, with Caulobacter henricii (96.8 %) and Caulobacter fusiformis (96.8 %) as its closest relatives. The non-prosthecate strain LMG 11050T and the prosthecate strain FWC 21T both belonged to the genus Phenylobacterium with Phenylobacterium koreense (96.9 %) and Phenylobacterium immobile (96.3 %) as the closest relatives. This affiliation was supported by chemotaxonomic data (polar lipids and cellular fatty acids). Physiological and biochemical tests allowed genotypic and phenotypic differentiation of the novel strains from all hitherto recognized species of the genera Caulobacter and Phenylobacterium. The strains therefore represent novel species, for which the names Caulobacter mirabilis sp. nov. (type strain FWC 38T=LMG 24261T=CCUG 55073T), Phenylobacterium conjunctum (type strain FWC 21T=LMG 24262T=CCUG 55074T), the first described prosthecate Phenylobacterium species, and Phenylobacterium haematophilum sp. nov. (type strain LMG 11050T=CCUG 26751T) are proposed. Marker nucleotides within the 16S rRNA genes were determined for the genera Asticcacaulis, Brevundimonas, Caulobacter and Phenylobacterium and the description of the genus Phenylobacterium is emended.
en
Phylogeny by a polyphasic approach of the order Caulobacterales, proposal of Caulobacter mirabilis sp. nov., Phenylobacterium haematophilum sp. nov. and Phenylobacterium conjunctum sp. nov., and emendation of the genus Phenylobacterium.
Article
oai:repository.helmholtz-hzi.de:10033/381442019-08-30T11:27:45Zcom_10033_620652col_10033_620675
Abraham, Wolf-Rainer
Macedo, Alexandre Jose
Gomez, Luiz Humberto
Tavarez, Flavio C. A.
2008-09-25T14:24:03Z
2008-09-25T14:24:03Z
2007-09-24
CLEAN- Soil, Air, Water, 35(2007)339-347
http://hdl.handle.net/10033/38144
null
Occurence and resistance of pathogenic bacteria along the Tiete river downstream of Soa Paulo in Brazil
Article
oai:repository.helmholtz-hzi.de:10033/889342021-03-24T01:36:23Zcom_10033_620652col_10033_620675
Menyailo, Oleg V.
Abraham, Wolf-Rainer
Conrad, Ralf
2010-01-06T15:35:52Z
2010-01-06T15:35:52Z
2010-01-01
Soil Biology and Biochemistry 2010, 42 (1):101-107
10.1016/j.soilbio.2009.10.005
http://hdl.handle.net/10033/88934
Tree species affect atmospheric CH4 oxidation without altering community composition of soil methanotrophs
Article
oai:repository.helmholtz-hzi.de:10033/995282019-08-30T11:35:12Zcom_10033_620652col_10033_620675
Estrela, Andréia Bergamo
Abraham, Wolf-Rainer
2010-05-21T11:05:06Z
2010-05-21T11:05:06Z
2010-05-21T11:05:06Z
Combining Biofilm-Controlling Compounds and Antibiotics as a Promising New Way to Control Biofilm Infections 2010, 3 (5):1374 Pharmaceuticals
1424-8247
10.3390/ph3051374
http://hdl.handle.net/10033/99528
Pharmaceuticals
null
biofilm
microbial community
quorum-sensing
quorum-quenching
antimicrobial therapy
Combining Biofilm-Controlling Compounds and Antibiotics as a Promising New Way to Control Biofilm Infections
Article
oai:repository.helmholtz-hzi.de:10033/1191322019-08-30T11:34:22Zcom_10033_620652col_10033_620675
Estrela, Andréia B
Abraham, Wolf-Rainer
2011-01-11T13:57:59Z
2011-01-11T13:57:59Z
2010-09
Brevundimonas vancanneytii sp. nov., isolated from blood of a patient with endocarditis. 2010, 60 (Pt 9):2129-34 Int. J. Syst. Evol. Microbiol.
1466-5026
19880635
10.1099/ijs.0.015651-0
http://hdl.handle.net/10033/119132
International journal of systematic and evolutionary microbiology
A Gram-negative, rod-shaped, non-spore-forming bacterial strain, designated LMG 2337(T), was isolated from the blood of a patient with endocarditis and characterized. The strain was affiliated with the alphaproteobacterial genus Brevundimonas, with Brevundimonas diminuta LMG 2089(T) (98.3 % 16S rRNA gene sequence similarity) and Brevundimonas terrae KSL-145(T) (97.5 %) as its closest relatives. This affiliation was supported by chemotaxonomic data: the G+C content was 66.3 mol %, the major polar lipids were phosphatidyl diacylglycerol, sulfoquinovosyl diacylglycerol and phosphatidyl glucopyranosyl diacylglycerol and the major fatty acids were summed feature 7 (one or more of C(18 : 1)ω 7c, C(18 : 1)ω 9t and C(18 : 1)ω 12t) and C(16 : 0). Strain LMG 2337(T) displayed an unusually broad substrate spectrum. The results from DNA-DNA hybridization and physiological and biochemical tests allowed the genotypic and phenotypic differentiation of strain LMG 2337(T) from all of the type strains of hitherto-described Brevundimonas species. The strain therefore represents a novel species, for which the name Brevundimonas vancanneytii sp. nov. is proposed, with type strain LMG 2337(T) (=CCUG 1797(T) =ATCC 14736(T)).
en
Brevundimonas vancanneytii sp. nov., isolated from blood of a patient with endocarditis.
Article
oai:repository.helmholtz-hzi.de:10033/1325412019-08-30T11:31:19Zcom_10033_620652col_10033_620675
Abraham, Wolf-Rainer
2011-06-03T13:43:30Z
2011-06-03T13:43:30Z
2011
Megacities as sources for pathogenic bacteria in rivers and their fate downstream. 2011, 2011 Int J Microbiol
1687-9198
20885968
10.1155/2011/798292
http://hdl.handle.net/10033/132541
International journal of microbiology
Poor sanitation, poor treatments of waste water, as well as catastrophic floods introduce pathogenic bacteria into rivers, infecting and killing many people. The goal of clean water for everyone has to be achieved with a still growing human population and their rapid concentration in large cities, often megacities. How long introduced pathogens survive in rivers and what their niches are remain poorly known but essential to control water-borne diseases in megacities. Biofilms are often niches for various pathogens because they possess high resistances against environmental stress. They also facilitate gene transfers of antibiotic resistance genes which become an increasing health problem. Beside biofilms, amoebae are carriers of pathogenic bacteria and niches for their survival. An overview about our current understanding of the fate and niches of pathogens in rivers, the multitude of microbial community interactions, and the impact of severe flooding, a prerequisite to control pathogens in polluted rivers, is given.
en
Megacities as sources for pathogenic bacteria in rivers and their fate downstream.
Article
oai:repository.helmholtz-hzi.de:10033/1997342019-08-30T11:31:49Zcom_10033_620652col_10033_620675
Pawelczyk, S
Bumann, D
Abraham, Wolf-Rainer
2012-01-02T14:05:02Z
2012-01-02T14:05:02Z
2011-02-07
Kinetics of carbon sharing in a bacterial consortium revealed by combining stable isotope probing with fluorescence-activated cell sorting. 2011: J. Appl. Microbiol.
1365-2672
21299770
10.1111/j.1365-2672.2011.04964.x
http://hdl.handle.net/10033/199734
Journal of applied microbiology
Aims: To determine the kinetics of substrate fluxes in a microbial community in order to elucidate the roles of the community members. Methods and Results: The kinetics of substrate sharing in a bacterial consortium were measured by a new analytical approach combining immunostaining, stable isotope probing and fluorescence-activated cell sorting (FACS). The bacterial consortium, consisting of four strains and growing on 4-chlorosalicylate (4-CS), was pulse-dosed with the degradation intermediate [U-(13) C]-4-chlorocatechol (4-CC). Cells were stained with strain-specific antibodies sorted by FACS and the (13) C-incorporation into fatty acids of the two most abundant members of the community was determined by isotope ratio mass spectrometry. From the two most abundant strains, the primary degrader Pseudomonas reinekei MT1 incorporated the labelled substrate faster than strain Achromobacter spanius MT3 but the maximal incorporation in strain MT3 was almost three times higher than in MT1. Conclusions: It has been reported that strain MT1 produces 4-CC as an intermediate but has a lower LD(50) for it than strain MT3; therefore, MT3 still degrades 4-CC when the concentrations of 4-CC are already too toxic, even lethal, for MT1. By degrading 4-CC, produced by MT1, MT3 protects the entire community against this toxin. The higher affinity but lower tolerance of strain MT1 for 4-chlorocatechol compared to strain MT3 explains the complementary function these two strains have in the consortium adding exceptional stability to the entire community. Significance and Impact of the Study: The novel approach can reveal carbon fluxes in microbial communities generating quantitative data for systems biology of the microbial community.
null
Kinetics of carbon sharing in a bacterial consortium revealed by combining stable isotope probing with fluorescence-activated cell sorting.
Article
oai:repository.helmholtz-hzi.de:10033/2036092019-08-30T11:34:22Zcom_10033_620652col_10033_620675
Estrela, A B
Abraham, Wolf-Rainer
2012-01-18T15:07:35Z
2012-01-18T15:07:35Z
2011
Adenosine in the inflamed gut: a Janus faced compound. 2011, 18 (18):2791-815 Curr. Med. Chem.
1875-533X
21649583
http://hdl.handle.net/10033/203609
Current medicinal chemistry
The purine ribonucleoside adenosine (Ado) has been recognized for its regulatory functions in situations of cellular stress like ischemia, hypoxia and inflammation. The importance of extracellular Ado as a modulator in the immune system is a theme of great appreciation and the focus of recent increasing interest in the field of gastrointestinal inflammation. In this review, the different aspects of Ado signaling during inflammatory responses in the gut are discussed, considering the contribution of the four known Ado receptors (ARs; A(1), A(2A), A(2B), and A(3)), their mechanisms and expression patterns. Activation of these receptors in epithelial cells as well as in immune cells recruited to the inflamed intestinal mucosa determines the overall effect, ranging from a protective, anti-inflammatory modulation to a strong pro-inflammatory induction. Here we present the current advances in agonists and antagonists development and their potential therapeutic application studied in animal models of intestinal inflammation. In addition, alternative complementary approaches to manipulate such a complex signaling system are discussed, for example, the use of AR allosteric modulators or interference with Ado metabolism. Special features of the gut environment are taken into account: the contribution of diet components; the involvement of Ado in intestinal infections; the interactions with the gut microbiome, particularly, the recent exciting finding that an intestinal bacterium can directly produce extracellular Ado in response to host defense mechanisms in an inflammation scenario. Understanding each component of this dynamic system will broaden the possibilities for applying Ado signaling as a therapeutic target in gut inflammation.
en
Adenosine in the inflamed gut: a Janus faced compound.
oai:repository.helmholtz-hzi.de:10033/2142212019-08-30T11:24:25Zcom_10033_620652col_10033_620675
Kramer, Rolf
Abraham, Wolf-Rainer
2012-03-05T15:25:32Z
2012-03-05T15:25:32Z
2012-03-05T15:25:32Z
Volatile sesquiterpenes from fungi: what are they good for? 2011, 11 (1):15 Phytochemistry Reviews
1568-7767
1572-980X
10.1007/s11101-011-9216-2
http://hdl.handle.net/10033/214221
Phytochemistry Reviews
null
Volatile sesquiterpenes from fungi: what are they good for?
Article
oai:repository.helmholtz-hzi.de:10033/2323142019-08-30T11:33:00Zcom_10033_620652col_10033_620675
Stiesch, Meike
Menzel, Henning
Abraham, Wolf-Rainer
Müller, Peter Paul
Dempwolf, Wiebke
Pfaffenroth, Cornelia
Kohorst, Phillip
Winkel, Andreas
2012-07-06T08:57:26Z
2012-07-06T08:57:26Z
2012-07-06
Chemische Funktionalisierung und Materialoptimierung dentaler Implantat-Abutments zur Reduktion der oralen Biofilmbildung 2010, :85 Sonderforschungsbereich 599
http://hdl.handle.net/10033/232314
Chemische Funktionalisierung und Materialoptimierung dentaler Implantat-Abutments zur Reduktion der oralen Biofilmbildung
Book chapter
oai:repository.helmholtz-hzi.de:10033/2436512019-08-30T11:35:14Zcom_10033_620652col_10033_620675
de Carvalho, M P
Abraham, Wolf-Rainer
2012-09-12T14:42:20Z
2012-09-12T14:42:20Z
2012-07-01
Antimicrobial and biofilm inhibiting diketopiperazines. 2012, 19 (21):3564-77 Curr. Med. Chem.
1875-533X
22709011
http://hdl.handle.net/10033/243651
Current medicinal chemistry
Diketopiperazines are the smallest cyclic peptides known. 90% of Gram-negative bacteria produce diketopiperazines and they have also been isolated from Gram-positive bacteria, fungi and higher organisms. Biosynthesis of cyclodipeptides can be achieved by dedicated nonribosomal peptide synthetases or by a novel type of synthetases named cyclopeptide synthases. Since the first report in 1924 a large number of bioactive diketopiperazines was discovered spanning activities as antitumor, antiviral, antifungal, antibacterial, antiprion, antihyperglycemic or glycosidase inhibitor agents. As infections are of increasing concern for human health and resistances against existing antibiotics are growing this review focuses on the antimicrobial activities of diketopiperazines. The antibiotic bicyclomycin is a diketopiperazine and structure activity studies revealed the unique nature of this compound which was finally developed for clinical applications. The antimicrobial activities of a number of other diketopiperazines along with structure activity relationships are discussed. Here a special focus is on the activity-toxicity problem of many compounds setting tight limitations to their application as drugs. Not only these classical antimicrobial activities but also proposed action in modulating bacterial communication as a new target to control biofilms will be evaluated. Pathogens organized in biofilms are difficult to eradicate because of the increase of their tolerance for antibiotics for several orders. Diketopiperazines were reported to modulate LuxR-mediated quorum-sensing systems of bacteria, and they are considered to influence cell-cell signaling offering alternative ways of biofilm control by interfering with microbial communication. Concluding the review we will finally discuss the potential of diketopiperazines in the clinic to erase biofilm infections.
en
Archived with thanks to Current medicinal chemistry
Antimicrobial and biofilm inhibiting diketopiperazines.
Article
oai:repository.helmholtz-hzi.de:10033/2943282019-08-30T11:36:05Zcom_10033_620652col_10033_620675
Macedo, Alexandre José
Kuhlicke, Ute
Neu, Thomas R
Timmis, Kenneth N
Abraham, Wolf-Rainer
2013-06-21T12:06:07Z
2013-06-21T12:06:07Z
2005-11
Three stages of a biofilm community developing at the liquid-liquid interface between polychlorinated biphenyls and water. 2005, 71 (11):7301-9 Appl. Environ. Microbiol.
0099-2240
16269772
10.1128/AEM.71.11.7301-7309.2005
http://hdl.handle.net/10033/294328
Applied and environmental microbiology
Soil contaminated with polychlorinated biphenyls (PCB) was used as an inoculum to grow a complex biofilm community on PCB oil (Aroclor 1242) on a substratum (Permanox). The biofilm was monitored for 31 days by confocal laser scanning microscopy, community fingerprinting using single-strand conformational polymorphism (SSCP), amplicons of the 16S rRNA genes, and chemical analyses of the PCB congeners. SSCP analysis of the young biofilm revealed a rather diverse microbial community with species of the genera Herbaspirillum and Bradyrhizobium as dominant members. The biofilm developing on the PCB droplets displayed pronounced stages of PCB degradation and biofilm development not described before from pure-culture experiments. The first step was the colonization of the substratum while the PCB oil was hardly populated. When a certain density of bacteria was reached on the Permanox, the PCB was colonized, but soon the degradation of the congeners was markedly reduced and many cells were damaged, as seen by LIVE/DEAD staining. Finally, the biofilm formed aggregates and invaded the PCB oil, showing lower numbers of damaged cells than before and a dramatic increase in PCB degradation. This sequence of biofilm formation is understood as a maturation process prior to PCB oil colonization. This is followed by a thin biofilm on the PCB droplet, an aggregation process forming pockets in the PCB, and finally an invasion of the biofilm into the PCB oil. Only the mature biofilm showed degradation of pentachlorinated PCB congeners, which may be reductively dechlorinated and the resulting trichlorobiphenyls then aerobically metabolized.
en
Archived with thanks to Applied and environmental microbiology
Three stages of a biofilm community developing at the liquid-liquid interface between polychlorinated biphenyls and water.
Article
oai:repository.helmholtz-hzi.de:10033/2944412019-08-30T11:34:48Zcom_10033_620652col_10033_620675
Scopel, Marina
Abraham, Wolf-Rainer
Henriques, Amélia T
Macedo, Alexandre J
2013-06-24T11:31:04Z
2013-06-24T11:31:04Z
2013-02-01
Dipeptide cis-cyclo(Leucyl-Tyrosyl) produced by sponge associated Penicillium sp. F37 inhibits biofilm formation of the pathogenic Staphylococcus epidermidis. 2013, 23 (3):624-6 Bioorg. Med. Chem. Lett.
1464-3405
23290053
10.1016/j.bmcl.2012.12.020
http://hdl.handle.net/10033/294441
Bioorganic & medicinal chemistry letters
Infections associated to microbial biofilms are involved in 80% of human infections and became a challenge concerning public health. Infections related to Staphylococcus epidermidis biofilms are presently commonly associated to medical devices, increasing treatment costs for this type of infection. Alternatives to eliminate this kind of disease have been employed in screening programs using diverse marine-derived fungi source of bioactive compounds capable to combat biofilm formation. In this work was isolated the dipeptide cis-cyclo(Leucyl-Tyrosyl) from a sponge associated Penicillium sp. possessing a remarkable inhibition up to 85% of biofilm formation without interfering with bacterial growth, confirmed by scanning electron microscopy. This is the first demonstration that cis-cyclo(Leucyl-Tyrosyl) is able to specifically inhibit biofilm formation adding another aspect to the broad spectrum of bioactivities of cyclic dipeptides.
en
Archived with thanks to Bioorganic & medicinal chemistry letters
Dipeptide cis-cyclo(Leucyl-Tyrosyl) produced by sponge associated Penicillium sp. F37 inhibits biofilm formation of the pathogenic Staphylococcus epidermidis.
Article
oai:repository.helmholtz-hzi.de:10033/2974412019-08-30T11:36:05Zcom_10033_620652col_10033_620675
Abraham, Wolf-Rainer
Lünsdorf, Heinrich
Vancanneyt, Marc
Smit, John
2013-08-06T08:46:22Z
2013-08-06T08:46:22Z
2013-06
Cauliform bacteria lacking phospholipids from an abyssal hydrothermal vent: proposal of Glycocaulis abyssi gen. nov., sp. nov., belonging to the family Hyphomonadaceae. 2013, 63 (Pt 6):2207-15 Int. J. Syst. Evol. Microbiol.
1466-5034
23148094
10.1099/ijs.0.047894-0
http://hdl.handle.net/10033/297441
International journal of systematic and evolutionary microbiology
Cauliform bacteria are prosthecate bacteria often specialized for oligotrophic environments. A polyphasic approach, comprising 16S rRNA gene sequencing, lipid analysis and salt tolerance characterizations, was used to clarify the taxonomy of one isolate, strain MCS 33(T), obtained from above the hot water plume of a deep-sea hydrothermal vent near Vancouver island, Canada. Cells contained no detectable phospholipids or sulpholipids, but did contain 1,2-di-O-acyl-3-O-α-D-glucopyranosylglycerol, 1,2-di-O-acyl-3-O-α-D-glucopyranuronosylglycerol and the novel lipid 1,2-di-O-acyl-3-[O-α-D-glucopyranuronosyl]glycerol-6'-N-glycine. It is assumed that the various glucoronosyl lipids are replacing, at least partially, the phospholipids in their various tasks in the cell cycle. The G+C content of the genomic DNA of strain MCS 33(T) was 62.8 mol%, and Q10 was the predominant respiratory ubiquinone. The 16S rRNA gene sequence of this chemoheterotrophic, aerobic, moderately halophilic strain showed only a low similarity of 94.4% to that of Oceanicaulis alexandrii C116-18(T), and both strains also differed based on their lipids. Although the novel strain was isolated from seawater sampled near a hydrothermal vent, its optimum temperature for growth was 30 °C. The main cellular fatty acids were C18:1ω7c, C18:0 and the unknown fatty acid ECL 11.798, and the main hydroxy fatty acid was C12:0 3-OH. The strain is proposed to represent a novel species of a new genus, Glycocaulis abyssi gen. nov., sp. nov. The type strain of the type species is MCS 33(T) (=LMG 27140(T)=CCUG 62981(T)).
en
Archived with thanks to International journal of systematic and evolutionary microbiology
Cauliform bacteria lacking phospholipids from an abyssal hydrothermal vent: proposal of Glycocaulis abyssi gen. nov., sp. nov., belonging to the family Hyphomonadaceae.
Article
oai:repository.helmholtz-hzi.de:10033/3018102019-08-30T11:25:11Zcom_10033_620652col_10033_620675
Estrela, Andreia Bergamo
Rohde, Manfred
Gutierrez, Maximiliano Gabriel
Molinari, Gabriella
Abraham, Wolf-Rainer
2013-09-18T14:28:59Z
2013-09-18T14:28:59Z
2013-09
Human β-Defensin 2 Induces Extracellular Accumulation of Adenosine in Escherichia coli. 2013, 57 (9):4387-93 Antimicrob. Agents Chemother.
1098-6596
23817371
10.1128/AAC.00820-13
http://hdl.handle.net/10033/301810
Antimicrobial agents and chemotherapy
Human β-defensins are host defense peptides performing antimicrobial as well as immunomodulatory functions. The present study investigated whether treatment of Escherichia coli with human β-defensin 2 could generate extracellular molecules of relevance for immune regulation. Mass spectrometry analysis of bacterial supernatants detected the accumulation of purine nucleosides triggered by β-defensin 2 treatment. Other cationic antimicrobial peptides tested presented variable outcomes with regard to extracellular adenosine accumulation; human β-defensin 2 was the most efficient at inducing this response. Structural and biochemical evidence indicated that a mechanism other than plain lysis was involved in the observed phenomenon. By use of isotope ((13)C) labeling, extracellular adenosine was found to be derived from preexistent RNA, and a direct interaction between the peptide and bacterial nucleic acid was documented for the first time for β-defensin 2. Taken together, the data suggest that defensin activity on a bacterial target may alter local levels of adenosine, a well-known immunomodulator influencing inflammatory processes.
en
Archived with thanks to Antimicrobial agents and chemotherapy
Human β-Defensin 2 Induces Extracellular Accumulation of Adenosine in Escherichia coli.
Article
oai:repository.helmholtz-hzi.de:10033/3022862019-08-30T11:28:46Zcom_10033_620652col_10033_620675
Abraham, Wolf-Rainer
2013-09-25T14:44:17Z
2013-09-25T14:44:17Z
2013-09-25
Stabile Isotope erlauben Einblicke in Bakteriengemeinschaften 2013, 19 (5):505 BIOspektrum
0947-0867
1868-6249
10.1007/s12268-013-0347-4
http://hdl.handle.net/10033/302286
BIOspektrum
Archived with thanks to BIOspektrum
Stabile Isotope erlauben Einblicke in Bakteriengemeinschaften
Article
oai:repository.helmholtz-hzi.de:10033/3228262019-08-30T11:34:43Zcom_10033_620652col_10033_620675
Abraham, Wolf-Rainer
2014-07-11T11:24:09Z
2014-07-11T11:24:09Z
2014-06
Applications and impacts of stable isotope probing for analysis of microbial interactions. 2014, 98 (11):4817-28 Appl. Microbiol. Biotechnol.
1432-0614
24715147
10.1007/s00253-014-5705-8
http://hdl.handle.net/10033/322826
Applied microbiology and biotechnology
Probing the interactions between microbes and their environment with stable isotopes became a powerful technique over the last years. While quadruple mass spectrometry or isotope ratio mass spectrometry (IRMS) require at least 300,000 bacterial cells, analysis at the single-cell level is possible with secondary ion mass spectrometry (SIMS) or Raman microspectrometry. While SIMS needs enrichments of more than 0.1 and Raman microscopy of more than 25 at.-%, IRMS can deal with 0.0001 at.-%. To find out who eats what, one has to discern between the different species in a community. Several methods have been introduced to discern between the different taxa in microbial communities, e.g., by using fatty acids as biomarkers, density centrifugation of DNA/RNA, or fluorescent in situ hybridization (FISH) with phylogenetic probes. While the biomarker approach can be coupled with the high sensitivity of the IRMS, the DNA approach gives in general a better phylogenetic resolution of the metabolic active microbes. A combination of both is the separation via coupling of FISH-probes to magnetic beads or fluorescent assisted cell sorting (FACS) of stained cells leading to fractions which can be analyzed by IRMS. Applying these techniques over a time course can reveal the metabolic kinetics and food webs. In this review, the different methods are presented with examples and their advantages and disadvantages are discussed. An outlook on the combination of the various techniques and their applications in microbial ecology is given.
en
Archived with thanks to Applied microbiology and biotechnology
Applications and impacts of stable isotope probing for analysis of microbial interactions.
Article
oai:repository.helmholtz-hzi.de:10033/3369912019-08-30T11:32:39Zcom_10033_620652col_10033_620675
Abraham, Wolf-Rainer
2014-12-09T15:00:54Z
2014-12-09T15:00:54Z
2014-12-09
1862-278X
0013-5585
10.1515/bmt-2014-5014
http://hdl.handle.net/10033/336991
Biomedical Engineering / Biomedizinische Technik
Different implants have different biofilm communities-lessons for implant optimization
Meetings and Proceedings
oai:repository.helmholtz-hzi.de:10033/5530812019-08-30T11:35:14Zcom_10033_620652col_10033_620675
Kramer, R
Sauer-Heilborn, A
Welte, T
Guzman, C A
Höfle, M G
Abraham, Wolf-Rainer
2015-05-18T12:06:00Z
2015-05-18T12:06:00Z
2015-04
A rapid method for breath analysis in cystic fibrosis patients. 2015, 34 (4):745-51 Eur. J. Clin. Microbiol. Infect. Dis.
1435-4373
25431363
10.1007/s10096-014-2286-5
http://hdl.handle.net/10033/553081
European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology
For easy handling and speed of lung diseases diagnostics, approaches based on volatile organic compounds (VOCs), including those emitted by pathogenic microorganisms, are considered but currently require considerable sampling efforts. We tested whether easy-to-handle and fast detection of lung infections is possible using solid-phase microextraction (SPME) of 100 ml of exhaled breath. An analytical procedure for the detection of VOCs from the headspace of epithelial lung cells infected with four human pathogens was developed. The feasibility of this method was tested in a cystic fibrosis (CF) outpatient clinic in vivo. Exhaled breath was extracted by SPME and analyzed by gas chromatography-mass spectrometry (GC-MS). The compositions of VOCs released in the infection model were characteristic for all individual pathogens tested. Exhaled breath of CF patients allowed clear distinction of CF patients and controls by their VOC compositions using multivariate analyses. Interestingly, the major specific VOCs detected in the exhaled breath of infected CF patients in vivo differed from those monitored during bacterial in vitro growth. SPME extraction of VOCs from 100 ml of human breath allowed the distinction between CF patients and healthy probands. Our results highlight the importance of assessing the entire pattern of VOCs instead of selected biomarkers for diagnostic purposes, as well as the need to use clinical samples to identify reliable biomarkers. This study provides the proof-of-concept for the approach using the composition of exhaled VOCs in human breath for the rapid identification of infectious agents in patients with lower respiratory tract infections.
en
A rapid method for breath analysis in cystic fibrosis patients.
Article
oai:repository.helmholtz-hzi.de:10033/5840852019-08-30T11:35:14Zcom_10033_620652col_10033_620675
Estrela, Andreia Bergamo
Türck, Patrick
Stutz, Elaine
Abraham, Wolf-Rainer
2015-12-18T10:26:56Z
2015-12-18T10:26:56Z
2015
Release of Periplasmic Nucleotidase Induced by Human Antimicrobial Peptide in E. coli Causes Accumulation of the Immunomodulator Adenosine. 2015, 10 (9):e0138033 PLoS ONE
1932-6203
26371472
10.1371/journal.pone.0138033
http://hdl.handle.net/10033/584085
PloS one
Previous work by our group described that human β-defensin-2 induces accumulation of extracellular adenosine (Ado) in E. coli cultures through a non-lytic mechanism causing severe plasmolysis. Here, we investigate the presence of AMP as a direct precursor and the involvement of a bacterial enzyme in the generation of extracellular Ado by treated bacteria. Following hBD-2 treatment, metabolites were quantified in the supernatants using targeted HPLC-MS/MS analysis. Microbial growth was monitored by optical density and cell viability was determined by colony forming units counts. Phosphatase activity was measured using chromogenic substrate pNPP. The results demonstrate that defensin-treated E. coli strain W releases AMP in the extracellular space, where it is converted to Ado by a bacterial soluble factor. An increase in phosphatase activity in the supernatant was observed after peptide treatment, similar to the effect of sucrose-induced osmotic stress, suggesting that the periplasmic 5'nucleotidase (5'-NT) is released following the plasmolysis event triggered by the peptide. Ado accumulation was enhanced in the presence of Co2+ ion and inhibited by EDTA, further supporting the involvement of a metallo-phosphatase such as 5'-NT in extracellular AMP conversion into Ado. The comparative analysis of hBD-induced Ado accumulation in different E. coli strains and in Pseudomonas aeruginosa revealed that the response is not correlated to the peptide's effect on cell viability, but indicates it might be dependent on the subcellular distribution of the nucleotidase. Taken together, these data shed light on a yet undescribed mechanism of host-microbial interaction: a human antimicrobial peptide inducing selective release of a bacterial enzyme (E. coli 5'-NT), leading to the formation of a potent immunomodulator metabolite (Ado).
en
Release of Periplasmic Nucleotidase Induced by Human Antimicrobial Peptide in E. coli Causes Accumulation of the Immunomodulator Adenosine.
Article
oai:repository.helmholtz-hzi.de:10033/6011412019-08-30T11:37:00Zcom_10033_620652col_10033_620675
de Carvalho, Maira Peres
Türck, Patrick
Abraham, Wolf-Rainer
2016-03-10T14:52:12Z
2016-03-10T14:52:12Z
2015
Secondary Metabolites Control the Associated Bacterial Communities of Saprophytic Basidiomycotina Fungi. 2015, 30 (2):196-8 Microbes Environ.
1347-4405
25904019
10.1264/jsme2.ME14139
http://hdl.handle.net/10033/601141
Microbes and environments / JSME
Fungi grow under humid conditions and are, therefore, prone to biofilm infections. A 16S rRNA fingerprint analysis was performed on 49 sporocarps of Basidiomycotina in order to determine whether they are able to control these biofilms. Ninety-five bacterial phylotypes, comprising 4 phyla and 10 families, were identified. While ectomycorrhizal fungi harbored the highest bacterial diversity, saprophytic fungi showed little or no association with bacteria. Seven fungal species were screened for antimicrobial and antibiofilm activities. Biofilm formation and bacterial growth was inhibited by extracts obtained from saprophytic fungi, which confirmed the hypothesis that many fungi modulate biofilm colonization on their sporocarps.
en
Secondary Metabolites Control the Associated Bacterial Communities of Saprophytic Basidiomycotina Fungi.
Article
oai:repository.helmholtz-hzi.de:10033/6046212019-08-30T11:27:42Zcom_10033_620652col_10033_620675
Abraham, Wolf-Rainer
2016-04-06T09:18:18Z
2016-04-06T09:18:18Z
2016
Going beyond the Control of Quorum-Sensing to Combat Biofilm Infections. 2016, 5 (1): Antibiotics (Basel)
2079-6382
27025518
10.3390/antibiotics5010003
http://hdl.handle.net/10033/604621
Antibiotics (Basel, Switzerland)
Most bacteria attach to surfaces where they form a biofilm, cells embedded in a complex matrix of polymers. Cells in biofilms are much better protected against noxious agents than free-living cells. As a consequence it is very difficult to control pathogens with antibiotics in biofilm infections and novel targets are urgently needed. One approach aims at the communication between cells to form and to maintain a biofilm, a process called quorum-sensing. Water soluble small-sized molecules mediate this process and a number of antagonists of these compounds have been found. In this review natural compounds and synthetic drugs which do not interfere with the classical quorum-sensing compounds are discussed. For some of these compounds the targets are still not known, but others interfere with the formation of exopolysaccharides, virulence factors, or cell wall synthesis or they start an internal program of biofilm dispersal. Some of their targets are more conserved among pathogens than the receptors for quorum sensing autoinducers mediating quorum-sensing, enabling a broader application of the drug. The broad spectrum of mechanisms, the diversity of bioactive compounds, their activity against several targets, and the conservation of some targets among bacterial pathogens are promising aspects for several clinical applications of this type of biofilm-controlling compound in the future.
en
Going beyond the Control of Quorum-Sensing to Combat Biofilm Infections.
Article
oai:repository.helmholtz-hzi.de:10033/6106842019-08-30T11:27:16Zcom_10033_620652col_10033_620675
Yuyama, Kamila Tomoko
Abraham, Wolf-Rainer
2016-05-25T13:19:31Z
2016-05-25T13:19:31Z
2016-05-06
cis-2-Alkenoic acids as promising drugs for the control of biofilm infections. 2016: Med Chem
1875-6638
27150962
http://hdl.handle.net/10033/610684
Medicinal chemistry (Shariqah (United Arab Emirates))
Microbes attached to surfaces and form biofilms where they are difficult to eradicate. Here they are embedded in a complex matrix of polymers and are much less sensitive against antibiotics or the immune system.
cis-2-Alkenoic acids as promising drugs for the control of biofilm infections.
Article
oai:repository.helmholtz-hzi.de:10033/6205412019-08-30T11:33:52Zcom_10033_620652col_10033_620675
Gebreil, Ahmed Shawky
Abraham, Wolf-Rainer
2016-10-05T09:41:17Z
2016-10-05T09:41:17Z
2016-08-03
Diversity and Activity of Bacterial Biofilm Communities Growing on Hexachlorocyclohexane 2016, 227 (9) Water, Air, & Soil Pollution
0049-6979
1573-2932
10.1007/s11270-016-2988-7
http://hdl.handle.net/10033/620541
Water, Air, & Soil Pollution
http://creativecommons.org/licenses/by-nc-sa/4.0/
Diversity and Activity of Bacterial Biofilm Communities Growing on Hexachlorocyclohexane
Article
oai:repository.helmholtz-hzi.de:10033/6205582019-08-30T11:27:16Zcom_10033_620533com_10033_620652com_10033_338554col_10033_621787col_10033_620534col_10033_620675
de Carvalho, Maira P
Gulotta, Giuseppe
do Amaral, Matheus W
Lünsdorf, Heinrich
Sasse, Florenz
Abraham, Wolf-Rainer
2016-10-20T07:47:09Z
2016-10-20T07:47:09Z
2016-10-03
Coprinuslactone protects the edible mushroom Coprinus comatus against biofilm infections by blocking both quorum-sensing and MurA. 2016 Environ. Microbiol.
1462-2920
27696655
10.1111/1462-2920.13560
http://hdl.handle.net/10033/620558
Environmental microbiology
Pathogens embedded in biofilms are involved in many infections and are very difficult to treat with antibiotics because of higher resistance compared to planktonic cells. Therefore, new approaches for their control are urgently needed. One way to search for biofilm dispersing compounds is to look at defense strategies of organisms exposed to wet environments, which makes them prone to biofilm infections. It is reasonable to assume that mushrooms have developed mechanisms to control biofilms on their sporocarps (fruiting bodies). A preliminary screening for biofilms on sporocarps revealed several species with few or no bacteria on their sporocarps. From the edible mushroom Coprinus comatus where no bacteria on the sporocarp could be detected (3R,4S)-2-methylene-3,4-dihydroxypentanoic acid 1,4-lactone, named coprinuslactone, was isolated. Coprinuslactone interfered with quorum-sensing and dispersed biofilms of Pseudomonas aeruginosa, where it also reduced the formation of the pathogenicity factors pyocyanin and rhamnolipid B. Coprinuslactone also damaged Staphylococcus aureus cells in biofilms at subtoxic concentrations. Furthermore, it inhibited UDP-N-acetylglucosamine enolpyruvyl transferase (MurA), essential for bacterial cell wall synthesis. These two modes of action ensure the inhibition of a broad spectrum of pathogens on the fruiting body but may also be useful for future clinical applications. This article is protected by copyright. All rights reserved.
http://creativecommons.org/licenses/by-nc-sa/4.0/
Coprinuslactone protects the edible mushroom Coprinus comatus against biofilm infections by blocking both quorum-sensing and MurA.
Article
oai:repository.helmholtz-hzi.de:10033/6206062019-08-30T11:26:13Zcom_10033_620652col_10033_620675
Estrela, Andréia Bergamo
Abraham, Wolf-Rainer
2016-11-29T09:11:41Z
2016-11-29T09:11:41Z
2010-05-11
Combining Biofilm-Controlling Compounds and Antibiotics as a Promising New Way to Control Biofilm Infections. 2010, 3 (5):1374-1393 Pharmaceuticals (Basel)
27713308
10.3390/ph3051374
http://hdl.handle.net/10033/620606
Pharmaceuticals (Basel, Switzerland)
Many bacteria grow on surfaces forming biofilms. In this structure, they are well protected and often high dosages of antibiotics cannot clear infectious biofilms. The formation and stabilization of biofilms are mediated by diffusible autoinducers (e.g. N-acyl homoserine lactones, small peptides, furanosyl borate diester). Metabolites interfering with this process have been identified in plants, animals and microbes, and synthetic analogues are known. Additionally, this seems to be not the only way to control biofilms. Enzymes capable of cleaving essential components of the biofilm matrix, e.g. polysaccharides or extracellular DNA, and thus weakening the biofilm architecture have been identified. Bacteria also have mechanisms to dissolve their biofilms and return to planktonic lifestyle. Only a few compounds responsible for the signalling of these processes are known, but they may open a completely novel line of biofilm control. All these approaches lead to the destruction of the biofilm but not the killing of the pathogens. Therefore, a combination of biofilm-destroying compounds and antibiotics to handle biofilm infections is proposed. In this article, different approaches to combine biofilm-controlling compounds and antibiotics to fight biofilm infections are discussed, as well as the balance between biofilm formation and virulence.
http://creativecommons.org/licenses/by-nc-sa/4.0/
Combining Biofilm-Controlling Compounds and Antibiotics as a Promising New Way to Control Biofilm Infections.
Article
oai:repository.helmholtz-hzi.de:10033/6205782019-08-30T11:35:09Zcom_10033_620652col_10033_620675
Estrela, Andréia
Abraham, Wolf-Rainer
2016-11-09T15:55:58Z
2016-11-09T15:55:58Z
2016-08-12
Fungal Metabolites for the Control of Biofilm Infections 2016, 6 (3):37 Agriculture
2077-0472
10.3390/agriculture6030037
http://hdl.handle.net/10033/620578
Agriculture
http://creativecommons.org/licenses/by-nc-sa/4.0/
Fungal Metabolites for the Control of Biofilm Infections
Article
oai:repository.helmholtz-hzi.de:10033/6209462019-08-30T11:34:17Zcom_10033_620652col_10033_620675
Scopel, Marina
Mothes, Beatriz
Lerner, Clea B.
Henriques, Am?lia T.
Macedo, Alexandre J.
Abraham, Wolf-Rainer
2017-06-15T07:54:24Z
2017-06-15T07:54:24Z
2017-06
Arvoredol: An unusual chlorinated and biofilm inhibiting polyketide from a marine Penicillium sp. of the Brazilian coast 2017, 20:73 Phytochemistry Letters
18743900
10.1016/j.phytol.2017.04.010
http://hdl.handle.net/10033/620946
Phytochemistry Letters
Penicillium sp. F37 has been isolated from the marine sponge Axinella corrugata and shown to be closely related to Penicillium maximae. From the culture of Penicillium sp. F37 arvoredol, a novel chlorinated polyketide with 6,7-dihydro-4(5H)-benzofuranone moiety has been isolated and characterized by spectroscopic methods Arvoredol prevented biofilm formation of the human pathogen Staphylococcus epidermidis at a concentration of 125 μg mL−1 by 40%. It was also active against colorectal carcinoma HCT116 cells with a MIC of 7.9 μg mL−1. © 2017 Phytochemical Society of Europe
http://creativecommons.org/licenses/by-nc-sa/4.0/
Arvoredol: An unusual chlorinated and biofilm inhibiting polyketide from a marine Penicillium sp. of the Brazilian coast
Article
oai:repository.helmholtz-hzi.de:10033/6210902019-08-30T11:26:11Zcom_10033_620652col_10033_620675
Abraham, Wolf-Rainer
2017-09-04T13:45:18Z
2017-09-04T13:45:18Z
2017-07-24
Fumitremorgins and Relatives - from Tremorgenic Compounds to Valuable Anti-Cancer Drugs. 2017 Curr. Med. Chem.
1875-533X
28738771
10.2174/0929867324666170724103410
http://hdl.handle.net/10033/621090
Current medicinal chemistry
Fumitremorgins are mycotoxins but can also inhibit cancer cells and reverse their drug resistance.
en
http://creativecommons.org/licenses/by-nc-sa/4.0/
Fumitremorgins and Relatives - from Tremorgenic Compounds to Valuable Anti-Cancer Drugs.
Article
oai:repository.helmholtz-hzi.de:10033/6212542019-08-30T11:30:32Zcom_10033_620857com_10033_620652col_10033_620858col_10033_620675
Yuyama, Kamila Tomoko
Chepkirui, Clara
Wendt, Lucile
Fortkamp, Diana
Stadler, Marc
Abraham, Wolf-Rainer
2018-01-24T14:28:13Z
2018-01-24T14:28:13Z
2017-12-12
Bioactive Compounds Produced by Hypoxylon fragiforme against Staphylococcus aureus Biofilms. 2017, 5 (4) Microorganisms
2076-2607
29231891
10.3390/microorganisms5040080
http://hdl.handle.net/10033/621254
Microorganisms
Treating infections organized in biofilms is a challenge due to the resistance of the pathogens against antibiotics and host immune cells. Many fungi grow in a wet environment, favorable for the growth of bacterial biofilms, and we speculated that fungi possess some strategies to control these bacterial biofilms. A fungus identified as Hypoxylon fragiforme, was collected in the Harz Mountains, Germany, and its mycelial culture was fermented in different culture media for 67 days to test its biological potential against bacterial biofilms. Sclerin, sclerin diacid and its 3-methyl monoester (methyl 1-(5-hydroxy-6-carboxylic-2,3,4-trimethylphenyl) propionate) are here described for the first time from this fungus. Sclerin and its diacid interfered with the biofilm formation of the pathogen Staphylococcus aureus, inhibiting 86% and 80% of the biofilm at 256 μg mL-1, respectively, but not killing the bacterium. Interestingly, the monomethylester of sclerin diacid was inactive. Although these compounds did not possess any activity against a pre-formed biofilm, they prevented its formation at subtoxic concentrations. Furthermore, sclerin and its diacid displayed a high specificity against Staphylococcus aureus, indicating a good strategy against pathogenic biofilms when combined with antibiotics.
en
http://creativecommons.org/licenses/by-nc-sa/4.0/
Bioactive Compounds Produced by Hypoxylon fragiforme against Staphylococcus aureus Biofilms.
Article
oai:repository.helmholtz-hzi.de:10033/6215892019-08-30T11:29:44Zcom_10033_56876com_10033_620652col_10033_620675col_10033_56896
Stüve, Philipp
Minarrieta, Lucía
Erdmann, Hanna
Arnold-Schrauf, Catharina
Swallow, Maxine
Guderian, Melanie
Krull, Freyja
Hölscher, Alexandra
Ghorbani, Peyman
Behrends, Jochen
Abraham, Wolf-Rainer
Hölscher, Christoph
Sparwasser, Tim D
Berod, Luciana
2018-11-28T10:14:16Z
2018-11-28T10:14:16Z
2018-01-01
1664-3224
29675017
10.3389/fimmu.2018.00495
http://hdl.handle.net/10033/621589
Mycobacterium tuberculosis (Mtb), the causative agent of human tuberculosis, is able to efficiently manipulate the host immune system establishing chronic infection, yet the underlying mechanisms of immune evasion are not fully understood. Evidence suggests that this pathogen interferes with host cell lipid metabolism to ensure its persistence. Fatty acid metabolism is regulated by acetyl-CoA carboxylase (ACC) 1 and 2; both isoforms catalyze the conversion of acetyl-CoA into malonyl-CoA, but have distinct roles. ACC1 is located in the cytosol, where it regulates de novo fatty acid synthesis (FAS), while ACC2 is associated with the outer mitochondrial membrane, regulating fatty acid oxidation (FAO). In macrophages, mycobacteria induce metabolic changes that lead to the cytosolic accumulation of lipids. This reprogramming impairs macrophage activation and contributes to chronic infection. In dendritic cells (DCs), FAS has been suggested to underlie optimal cytokine production and antigen presentation, but little is known about the metabolic changes occurring in DCs upon mycobacterial infection and how they affect the outcome of the immune response. We therefore determined the role of fatty acid metabolism in myeloid cells and T cells during Mycobacterium bovis BCG or Mtb infection, using novel genetic mouse models that allow cell-specific deletion of ACC1 and ACC2 in DCs, macrophages, or T cells. Our results demonstrate that de novo FAS is induced in DCs and macrophages upon M. bovis BCG infection. However, ACC1 expression in DCs and macrophages is not required to control mycobacteria. Similarly, absence of ACC2 did not influence the ability of DCs and macrophages to cope with infection. Furthermore, deletion of ACC1 in DCs or macrophages had no effect on systemic pro-inflammatory cytokine production or T cell priming, suggesting that FAS is dispensable for an intact innate response against mycobacteria. In contrast, mice with a deletion of ACC1 specifically in T cells fail to generate efficient T helper 1 responses and succumb early to Mtb infection. In summary, our results reveal ACC1-dependent FAS as a crucial mechanism in T cells, but not DCs or macrophages, to fight against mycobacterial infection.
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Mycobacterium bovis BCG
Mycobacterium tuberculosis
acetyl-CoA carboxylase 1
acetyl-CoA carboxylase 2
dendritic cells
fatty acid oxidation
fatty acid synthesis
macrophages
De Novo Fatty Acid Synthesis During Mycobacterial Infection Is a Prerequisite for the Function of Highly Proliferative T Cells, But Not for Dendritic Cells or Macrophages.
Article
oai:repository.helmholtz-hzi.de:10033/6216402019-11-21T12:09:03Zcom_10033_620857com_10033_620652col_10033_620858col_10033_620675
Yuyama, Kamila Tomoko
Wendt, Lucile
Surup, Frank
Kretz, Robin
Chepkirui, Clara
Wittstein, Kathrin
Boonlarppradab, Chollaratt
Wongkanoun, Sarunyou
Luangsa-Ard, Jennifer
Stadler, Marc
Abraham, Wolf-Rainer
2019-01-10T09:51:58Z
2019-01-10T09:51:58Z
2018-10-30
Biomolecules. 2018 Oct 30;8(4). pii: biom8040129. doi: 10.3390/biom8040129
2218-273X
30380779
10.3390/biom8040129
http://hdl.handle.net/10033/621640
Biomolecules
During the course of our ongoing work to discover new inhibitors of biofilm formation of Staphylococcus aureus from fungal sources, we observed biofilm inhibition by cytochalasans isolated from cultures of the ascomycete Hypoxylon fragiforme for the first time. Two new compounds were purified by a bioassay-guided fractionation procedure; their structures were elucidated subsequently by nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry (HR-MS). This unexpected finding prompted us to test further cytochalasans from other fungi and from commercial sources for comparison. Out of 21 cytochalasans, 13 showed significant inhibition of Staphylococcus aureus biofilm formation at subtoxic levels. These findings indicate the potential of cytochalasans as biofilm inhibitors for the first time, also because the minimum inhibitory concentrations (MIC) are independent of the anti-biofilm activities. However, cytochalasans are known to be inhibitors of actin, making some of them very toxic for eukaryotic cells. Since the chemical structures of the tested compounds were rather diverse, the inclusion of additional derivatives, as well as the evaluation of their selectivity against mammalian cells vs. the bacterium, will be necessary as next step in order to develop structure-activity relationships and identify the optimal candidates for development of an anti-biofilm agent. View Full-Text
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Attribution-NonCommercial-ShareAlike 4.0 International
Xylariales
ascomycota
bacterial pathogens
biofilm dispersion
chromatography
natural products
secondary metabolites
structure elucidation
Cytochalasans Act as Inhibitors of Biofilm Formation of Staphylococcus Aureus.
Article
oai:repository.helmholtz-hzi.de:10033/6218962019-08-30T11:26:41Zcom_10033_620636com_10033_620652col_10033_620675col_10033_620637
Kordes, Adrian
Grahl, Nora
Koska, Michal
Preusse, Matthias
Arce-Rodriguez, Alejandro
Abraham, Wolf-Rainer
Kaever, Volkhard
Häussler, Susanne
2019-08-13T08:38:38Z
2019-08-13T08:38:38Z
2019-08-01
ISME J. 2019 Aug;13(8):2018-2030. doi: 10.1038/s41396-019-0412-1. Epub 2019 Apr 5.
1751-7370
30952997
10.1038/s41396-019-0412-1
http://hdl.handle.net/10033/621896
ISME
In a given habitat, bacterial cells often experience recurrent exposures to the same environmental stimulus. The ability to memorize the past event and to adjust current behaviors can lead to efficient adaptation to the recurring stimulus. Here we demonstrate that the versatile bacterium Pseudomonas aeruginosa adopts a virulence phenotype after serial passage in the invertebrate model host Galleria mellonella. The virulence phenotype was not linked to the acquisition of genetic variations and was sustained for several generations, despite cultivation of the ex vivo virulence-adapted P. aeruginosa cells under rich medium conditions in vitro. Transcriptional reprogramming seemed to be induced by a host-specific food source, as reprogramming was also observed upon cultivation of P. aeruginosa in rich medium supplemented with polyunsaturated long-chain fatty acids. The establishment of induced memory responses adds a time dimension and seems to fill the gap between long-term evolutionary genotypic adaptation and short-term induced individual responses. Efforts to unravel the fundamental mechanisms that underlie the carry-over effect to induce such memory responses will continue to be of importance as hysteretic behavior can serve survival of bacterial populations in changing and challenging habitats.
en
http://creativecommons.org/licenses/by-nc-sa/4.0/
openAccess
Attribution-NonCommercial-ShareAlike 4.0 International
Establishment of an induced memory response in Pseudomonas aeruginosa during infection of a eukaryotic host.
Article
oai:repository.helmholtz-hzi.de:10033/6221212020-02-07T03:09:29Zcom_10033_620652col_10033_620675
Grigoletto, Diana Fortkamp
Correia, Ana Maria Lima
Abraham, Wolf-Rainer
Rodrigues, Andre
Assis, Marco Antonio
Ferreira, Antonio Gilberto
Massaroli, Michelli
Lira, Simone Possedente de
2020-02-06T09:20:30Z
2020-02-06T09:20:30Z
2019-12-18
1807-863X
1679-9283
10.4025/actascibiolsci.v41i1.48785
http://hdl.handle.net/10033/622121
Fungi are present in the most diverse environments including the interior of plant tissues,
living as endophytes without causing apparent damage. These endophytes are producers of secondary
metabolites, also known as natural products, such as fungicides. Here, we evaluated the ethyl acetate
fractions obtained from endophytic fungi isolated from plants in the genus Begonia. The fractions were
submitted to inhibitory test against the plant pathogens Diaporthe phaseolorum and Colletotrichum
gloeosporioides. From the 88 ethyl acetate fractions evaluated, 14.7 % inhibited C. gloeosporioides and 11.3 %
inhibited D. phaseolorum. One fungal isolate displaying an active fraction was selected for chemical
investigation. The fungus identified as Neopestalotiopsis sp., produced a compound that was active against
D. phaseolorum, with a MIC of 312 µg mL-1 (1,695.3 µM). The compound was identified by mass
spectrometry and 1H NMR as the known compound fumiquinone B. The results highlight that the
endophytes are capable of producing compounds that may be used to control plant pathogens. The
compound fumiquinone B is reported for the first time as an antifungal agent against D. phaseolorum, a
relevant plant pathogen worldwide. This is also the first report of the production of fumiquinone B by the
genus Neopestalotiopsis.
en
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General Biochemistry, Genetics and Molecular Biology
General Agricultural and Biological Sciences
2,6-hydroxy-5-methoxy-3-methylcyclohexa-2,5-diene-1,4-dione
Neopestalotiopsis sp.
Diaporthe phaseolorum
Secondary metabolites produced by endophytic fungi: novel antifungal activity of fumiquinone B
Article
oai:repository.helmholtz-hzi.de:10033/6223042020-06-20T01:41:13Zcom_10033_620652col_10033_620675
Renzi, Daniele Fernanda
de Almeida Campos, Laís
Miranda, Eduardo Hösel
Mainardes, Rubiana Mara
Abraham, Wolf-Rainer
Grigoletto, Diana Fortkamp
Khalil, Najeh Maissar
2020-06-19T11:07:32Z
2020-06-19T11:07:32Z
2020-03-30
Curr Med Chem. 2020;10.2174/0929867327666200330143338. doi:10.2174/0929867327666200330143338.
32223729
10.2174/0929867327666200330143338
http://hdl.handle.net/10033/622304
1875-533X
Current medicinal chemistry
The Fungal infections are diseases that are considered neglected although their infection rates have increased worldwide in the last decades. Thus, since the antifungal arsenal is restricted and many strains have shown resistance new therapeutic alternatives are necessary. Nanoparticles are considered important alternatives to promote drug delivery. In this sense, the objective of the present study was to evaluate the contributions of newly developed nanoparticles to the treatment of fungal infections. Studies have shown that nanoparticles generally improve the biopharmaceutical and pharmacokinetic characteristics of antifungals, which is reflected in a greater pharmacodynamic potential and lower toxicity, as well as the possibility of prolonged action. It also offers the proposition of new routes of administration. Nanotechnology is known to contribute to a new drug delivery system, not only for the control of infectious diseases, but for various other diseases as well. In recent years, several studies have emphasized its application in infectious diseases, presenting better alternatives for the treatment of fungal infections.
en
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Attribution-NonCommercial-ShareAlike 4.0 International
azoles
echinocandins
fungal infection
nanotechnology
polyenes.
Nanoparticles as A Tool for Broadening Antifungal Activities.
Article
oai:repository.helmholtz-hzi.de:10033/6223502020-07-15T02:28:12Zcom_10033_620652col_10033_620675
Abraham, Wolf-Rainer
2020-07-14T14:23:29Z
2020-07-14T14:23:29Z
2020-06-21
Curr Med Chem. 2020;10.2174/092986732728200621213702. doi:10.2174/092986732728200621213702.
32571199
10.2174/092986732728200621213702
http://hdl.handle.net/10033/622350
1875-533X
Current medicinal chemistry
non listed abstract
en
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Attribution-NonCommercial-ShareAlike 4.0 International
Commentary on "Antimicrobial Capacity of Plant Polyphenols against Gram-positive Bacteria: A Comprehensive Review" authored by Enrique Barrajón-Catalán, Institute of Molecular and Cell Biology (IBMC), Miguel Hernandez University (UMH), Avda. Universidad s/n, Elche 03202. Spain.
Commentary
oai:repository.helmholtz-hzi.de:10033/6228802021-05-21T01:52:10Zcom_10033_620652col_10033_620675
Lopes, Vanessa Falchetti
Giongo, Camila Nascimento
de Almeida Campos, Laís
Abraham, Wolf-Rainer
Mainardes, Rubiana Mara
Khalil, Najeh Maissar
2021-05-20T08:59:49Z
2021-05-20T08:59:49Z
2020-11-24
Curr Med Chem. 2020 Nov 24. doi: 10.2174/0929867328666201124152945. Epub ahead of print.
33234090
10.2174/0929867328666201124152945
http://hdl.handle.net/10033/622880
1875-533X
Current medicinal chemistry
The development of biodegradable nanoparticles is an important tool for the biological transport of chemical compounds. The nanoencapsulation reduces the biopharmaceutical and pharmacokinetic drawbacks of compounds and enhances their biological properties. Naturally occurring polymers such as proteins and polysaccharides have been widely applied in the development of nanostructured systems of several therapeutic agents. Among them is chitosan, a crustacean-carapace-chitin derived biopolymer. In addition to its biocompatibility and biodegradability, chitosan is known for its mucoadhesion properties. Chitosan-based nanostructured systems potentiate most of aspects of the loaded drugs, including cellular transport and other biological effects. The use of chitosan nanoparticles enhances permeation, stability and bioactivity of natural compounds. In this review, an overview of the main features of chitosan nanoparticles that improved in vitro and in vivo effects of bioactive natural molecules is given, emphasizing the results obtained with curcumin.
en
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Attribution 4.0 International
bioavailability
chitosan
curcumin
mucoadhesion.
nanoparticles
Chitosan nanoparticles potentiate the in vitro and in vivo effects of curcumin and other natural compounds.
Article
oai:repository.helmholtz-hzi.de:10033/6231762022-05-06T01:50:47Zcom_10033_620652col_10033_620675
Yuyama, Kamila Tomoko
Rohde, Manfred
Molinari, Gabriella
Stadler, Marc
Abraham, Wolf-Rainer
2022-05-05T13:17:26Z
2022-05-05T13:17:26Z
2020-11-08
2079-6382
33171584
10.3390/antibiotics9110788
http://hdl.handle.net/10033/623176
Antibiotics (Basel, Switzerland)
Infections involving biofilms are difficult to treat due to increased resistances against antibiotics and the immune system. Hence, there is an urgent demand for novel drugs against biofilm infections. During our search for novel biofilm inhibitors from fungi, we isolated linoleic acid from the ascomycete Hypoxylon fragiforme which showed biofilm inhibition of several bacteria at sub-MIC concentrations. Many fatty acids possess antimicrobial activities, but their minimum inhibitory concentrations (MIC) are high and reports on biofilm interferences are scarce. We demonstrated that not only linoleic acid but several unsaturated long-chain fatty acids inhibited biofilms at sub-MIC concentrations. The antibiofilm activity exerted by long-chain fatty acids was mainly against Gram-positive bacteria, especially against Staphylococcus aureus. Micrographs of treated S. aureus biofilms revealed a reduction in the extracellular polymeric substances, pointing to a possible mode of action of fatty acids on S. aureus biofilms. The fatty acids had a strong species specificity. Poly-unsaturated fatty acids had higher activities than saturated ones, but no obvious rule could be found for the optimal length and desaturation for maximal activity. As free fatty acids are non-toxic and ubiquitous in food, they may offer a novel tool, especially in combination with antibiotics, for the control of biofilm infections.
en
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Attribution 4.0 International
Gram-positive bacteria
Hypoxylon fragiforme
Staphylococcus aureus
biofilm inhibition
fatty acid
Unsaturated Fatty Acids Control Biofilm Formation of Staphylococcus aureus and Other Gram-Positive Bacteria.
Article