-
Journal of Microbiological Methods Apr 2021Modern aquaculture systems are designed for intensive rearing of fish or other species. Both land-based and offshore systems typically contain high loads of biomass and...
Modern aquaculture systems are designed for intensive rearing of fish or other species. Both land-based and offshore systems typically contain high loads of biomass and the water quality in these systems is of paramount importance for fish health and production. Microorganisms play a crucial role in removal of organic matter and nitrogen-recycling, production of toxic hydrogen sulfide (HS), and can affect fish health directly if pathogenic for fish or exerting probiotic properties. Methods currently used in aquaculture for monitoring certain bacteria species numbers still have typically low precision, specificity, sensitivity and are time-consuming. Here, we demonstrate the use of Digital PCR as a powerful tool for absolute quantification of sulfate-reducing bacteria (SRB) and major pathogens in salmon aquaculture, Moritella viscosa, Yersinia ruckeri and Flavobacterium psychrophilum. In addition, an assay for quantification of Listeria monocytogenes, which is a human pathogen bacterium and relevant target associated with salmonid cultivation in recirculating systems and salmon processing, has been assessed. Sudden mass mortality incidents caused by HS produced by SRB have become of major concern in closed aquaculture systems. An ultra-sensitive assay for quantification of SRB has been established using Desulfovibrio desulfuricans as reference strain. The use of TaqMan® probe technology allowed for the development of multi-plex assays capable of simultaneous quantification of these aquaculture priority bacteria. In single-plex assays, limit of detection was found to be at around 20 fg DNA for M. viscosa, Y. ruckeri and F. psychrophilum, and as low as 2 fg DNA for L. monocytogenes and D. desulfuricans.
Topics: Animals; Aquaculture; Fish Diseases; Flavobacterium; Fresh Water; Listeria monocytogenes; Moritella; Polymerase Chain Reaction; Salmon; Sulfates; Yersinia ruckeri
PubMed: 33610596
DOI: 10.1016/j.mimet.2021.106171 -
Canadian Journal of Microbiology Sep 2018Growth of two dissimilatory sulfate-reducing bacteria, Desulfosporosinus orientis (gram-positive) and Desulfovibrio desulfuricans (gram-negative), in a chemically...
Growth of two dissimilatory sulfate-reducing bacteria, Desulfosporosinus orientis (gram-positive) and Desulfovibrio desulfuricans (gram-negative), in a chemically defined culture medium resulted in similar growth rates (doubling times for each culture = 2.8 h) and comparable rates of HS generation (D. orientis = 0.19 nmol/L S per cell per h; D. desulfuricans = 0.12 nmol/L S per cell per h). Transmission electron microscopy of whole mounts and thin sections revealed that the iron sulfide mineral precipitates produced by the two cultures were morphologically different. The D. orientis culture flocculated, with the minerals occurring as subhedral plate-like precipitates, which nucleated on the cell wall during exponential growth producing extensive mineral aggregates following cell autolysis and endospore release. In contrast, the D. desulfuricans culture produced fine-grained colloidal or platy iron sulfide precipitates primarily within the bulk solution. Mineral analysis by scanning electron microscopy - energy dispersive spectroscopy indicated that neither culture promoted advanced mineral development beyond a 1:1 Fe:S stoichiometry. This analysis did not detect pyrite (FeS). The average Fe:S ratios were 1 : 1.09 ± 0.03 at 24 h and 1 : 1.08 ± 0.03 at 72 h for D. orientis and 1 : 1.05 ± 0.02 at 24 h and 1 : 1.09 ± 0.07 at 72 h for D. desulfuricans. The formation of "biogenic" iron sulfides by dissimilatory sulfate-reducing bacteria is influenced by bacterial cell surface structure, chemistry, and growth strategy, i.e., mineral aggregation occurred with cell autolysis of the gram-positive bacterium.
Topics: Bacteriolysis; Cell Wall; Desulfovibrio desulfuricans; Iron; Minerals; Oxidation-Reduction; Peptococcaceae; Sulfates; Sulfides
PubMed: 30169128
DOI: 10.1139/cjm-2017-0545 -
Frontiers in Microbiology 2021Proton release and uptake induced by metabolic activities were measured in non-buffered cell suspensions by means of a pH electrode. Recorded data were used for...
Proton release and uptake induced by metabolic activities were measured in non-buffered cell suspensions by means of a pH electrode. Recorded data were used for simulating substrate turnover rates by means of a new freeware app (). The program applies Michaelis-Menten or first-order kinetics to the metabolic processes and allows for parametrization of simultaneously ongoing processes. The simulation includes changes of the transmembrane ΔpH, membrane potential and ATP gains, and demonstrates the principles of chemiosmotic energy conservation. In our experiments, the versatile sulfate-reducing bacterium CSN (DSM 9104) was used as model organism. We analysed sulfate uptake by proton-sulfate symport, scalar alkalinization by sulfate reduction to sulfide, as well as nitrate and nitrite reduction to ammonia, and electron transport-coupled proton translocation. Two types of experiments were performed: In oxidant pulse experiments, cells were kept under H, and micromolar amounts of sulfate, nitrate or nitrite were added. For reductant pulse experiments, small amounts of H-saturated KCl were added to cells incubated under N with an excess of one of the above-mentioned electron acceptors. To study electron-transport driven proton translocation, the membrane potential was neutralized by addition of KSCN (100 mM). H/e ratios of electron-transport driven proton translocation were calculated by simulation with . This method gave lower but more realistic values than logarithmic extrapolation. We could verify the kinetic simulation parameters found with using series of increasing additions of the reactants. Our approach allows for studying a broad variety of proton-related metabolic activities at micromolar concentrations and time scales of seconds to minutes.
PubMed: 33995312
DOI: 10.3389/fmicb.2021.654065 -
Journal of Bacteriology Jan 1977Different electron carriers of the non-desulfoviridin-containing, sulfate-reducing bacterium Desulfovibrio desulfuricans (Norway strain) have been studied. Two nonheme... (Comparative Study)
Comparative Study
Different electron carriers of the non-desulfoviridin-containing, sulfate-reducing bacterium Desulfovibrio desulfuricans (Norway strain) have been studied. Two nonheme iron proteins, ferredoxin and rubredoxin, have been purified. This ferredoxin contains four atoms of non-heme iron and acid-labile sulfur and six residues of cysteine per molecule. Its amino acid composition suggests that it is homologous with the other Desulfovibrio ferredoxins. The rubredoxin is also an acidic protein of 6,000 molecular weight and contains one atom of iron and four cysteine residues per molecule. The amino acid composition and molecular weight of the cytochrome c3 from D. desulfuricans (strain Norway 4) are reported. Its spectral properties are very similar to those of the other cytochromes c3 (molecular weight, 13,000) of Desulfovibrio and show that it contains four hemes per molecule. This cytochrome has a very low redox potential and acts as a carrier in the coupling of hydrogenase and thiosulfate reductase in extracts of Desulfovibrio gigas and Desulfovibrio desulfuricans (Norway strain) in contrast to D. gigas cytochrome c3 (molecular weight, 13,000). A comparison of the activities of the cytochrome c3 (molecular weight, 13,000) of D. gigas and that of D. desulfuricans in this reaction suggests that these homologous proteins can have different specificity in the electron transfer chain of these bacteria.
Topics: Amino Acids; Cytochrome c Group; Desulfovibrio; Electron Transport; Ferredoxins; Iron; Molecular Weight; Rubredoxins; Species Specificity
PubMed: 187570
DOI: 10.1128/jb.129.1.30-38.1977 -
Scientific Reports Jul 2017Surface nanopatterning of metals has been an effective technique for improved performance and functionalization. However, it is of great challenge to fabricate...
Surface nanopatterning of metals has been an effective technique for improved performance and functionalization. However, it is of great challenge to fabricate nanostructure on carbon steels despite their extensive use and urgent needs to maintain the performance reliability and durability. Here, we report a one-step anodization technique to nanopattern a carbon steel in 50 wt.% NaOH solution for highly effective anti-adhesion by sulphate reducing bacteria (SRB), i.e., Desulfovibrio desulfuricans subsp. desulfuricans (Beijerinck) Kluyver and van Niel. We characterize the morphology, structure, composition, and surface roughness of the nanostructured film formed on the steel as a function of anodizing potential. We quantify the surface hydrophobicity by contact angle measurements, and the SRB adhesion by fluorescent analysis. The optimal anodization potential of 2.0 V is determined for the best performance of anti-adhesion of SRB to the steel, resulting in a 23.5 times of reduction of SRB adhesion compared to bare steel. We discuss the mechanisms for the film formation on the steel during anodization, and the high-performance anti-adhesion of bacteria to nanopatterned steels. Our technique is simple, cost-effective and environment-friendly, providing a promising alternative for industry-scale surface nanopatterning of carbon steels for effective controlling of bacterial adhesion.
Topics: Bacterial Adhesion; Desulfovibrio desulfuricans; Hydrophobic and Hydrophilic Interactions; Nanotubes, Carbon; Steel; Surface Properties
PubMed: 28706204
DOI: 10.1038/s41598-017-05626-0 -
Transplantation Jul 2024Despite ongoing improvements to regimens preventing allograft rejection, most cardiac and other organ grafts eventually succumb to chronic vasculopathy, interstitial...
BACKGROUND
Despite ongoing improvements to regimens preventing allograft rejection, most cardiac and other organ grafts eventually succumb to chronic vasculopathy, interstitial fibrosis, or endothelial changes, and eventually graft failure. The events leading to chronic rejection are still poorly understood and the gut microbiota is a known driving force in immune dysfunction. We previously showed that gut microbiota dysbiosis profoundly influences the outcome of vascularized cardiac allografts and subsequently identified biomarker species associated with these differential graft outcomes.
METHODS
In this study, we further detailed the multifaceted immunomodulatory properties of protolerogenic and proinflammatory bacterial species over time, using our clinically relevant model of allogenic heart transplantation.
RESULTS
In addition to tracing longitudinal changes in the recipient gut microbiome over time, we observed that Bifidobacterium pseudolongum induced an early anti-inflammatory phenotype within 7 d, whereas Desulfovibrio desulfuricans resulted in a proinflammatory phenotype, defined by alterations in leukocyte distribution and lymph node (LN) structure. Indeed, in vitro results showed that B pseudolongum and D desulfuricans acted directly on primary innate immune cells. However, by 40 d after treatment, these 2 bacterial strains were associated with mixed effects in their impact on LN architecture and immune cell composition and loss of colonization within gut microbiota, despite protection of allografts from inflammation with B pseudolongum treatment.
CONCLUSIONS
These dynamic effects suggest a critical role for early microbiota-triggered immunologic events such as innate immune cell engagement, T-cell differentiation, and LN architectural changes in the subsequent modulation of protolerant versus proinflammatory immune responses in organ transplant recipients.
Topics: Heart Transplantation; Gastrointestinal Microbiome; Bifidobacterium; Graft Rejection; Animals; Male; Time Factors; Graft Survival; Dysbiosis; Mice, Inbred C57BL; Immunity, Innate; Immunomodulation; Phenotype; Probiotics; Lymph Nodes
PubMed: 38587506
DOI: 10.1097/TP.0000000000004939 -
Revista Espanola de Quimioterapia :... Dec 2023
Identification of curved Gram-negative rods by MALDI-TOF mass spectrometer in a patient with Fournier ́s gangrene. A bacteremia caused by Desulfovibrio desulfuricans and Escherichia coli.
Topics: Humans; Desulfovibrio desulfuricans; Escherichia coli; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Gangrene; Bacteremia; Gram-Negative Bacteria
PubMed: 37767548
DOI: 10.37201/req/026.2023 -
The Biochemical Journal Feb 1983The membrane-bound hydrogenase from the anaerobic sulphate-reducing bacterium Desulfovibrio desulfuricans (Norway strain) has been purified to homogeneity, with an...
The membrane-bound hydrogenase from the anaerobic sulphate-reducing bacterium Desulfovibrio desulfuricans (Norway strain) has been purified to homogeneity, with an overall 80-fold purification and a specific activity of 70 mumol of H2 evolved/min per mg of protein. The hydrogenase had a relative molecular mass of 58 000 as determined by gel filtration and was estimated to contain six iron atoms and six acid-labile sulphur groups per molecule. The absorption spectrum of the enzyme was characteristic of an iron-sulphur protein. The E400 and E280 were 28 500 and 109 000 M-1.cm-1 respectively. The e.s.r. of the oxidized protein indicated the presence of [4Fe-4S]3+ or [3Fe-3S]3+, and another paramagnetic centre, probably Ni(III). The hydrogenase was inhibited by heavy-metal salts, carbon monoxide and high ionic strength. However, it was resistant to inhibition by thiol-blocking and metal-complexing reagents. N-Bromosuccinimide totally inhibited the enzyme activity at low concentrations. The enzyme was stable to O2 over long periods and to high temperatures. It catalyses both H2-evolution and H2-uptake with a variety of artificial electron carriers. D. desulfuricans cytochrome C3, its natural electron carrier, had a high affinity for the enzyme (Km = 2 microns). Rate enhancement was observed when cytochrome C3 was added to Methyl Viologen in the H2-evolution assay. The pH optimum for H2-evolution was 6.5.
Topics: Amino Acids; Cell Membrane; Desulfovibrio; Electron Spin Resonance Spectroscopy; Electrophoresis, Polyacrylamide Gel; Hydrogenase; Molecular Weight; Oxidoreductases; Oxygen; Spectrophotometry; Temperature
PubMed: 6303306
DOI: 10.1042/bj2090445 -
Revista Argentina de Microbiologia 2017Two cases of insidious bacteremia by uncommon curve and spiral-shaped, motile anaerobic gram-negative rods are presented. Both of them were of an unclear origin and...
Two cases of insidious bacteremia by uncommon curve and spiral-shaped, motile anaerobic gram-negative rods are presented. Both of them were of an unclear origin and occurred in immunosuppressed patients with simultaneous diseases. The key tests for the identification of Anaerobiospirillum were its micromorphology, a strictly anaerobic condition, negative catalase activity, the special-potency disk profile, glucose fermentation, and β-NAG production. Desulfovibrio species was identified by all the above preliminary tests but with a different disk profile, as well as for being asaccharolytic and desulfoviridin and HS producer. We here alert about the resistance or intermediate susceptibility of Anaerobiospirillum succiniciproducens against antimicrobial agents, such as metronidazole, one of the first-line drugs used for the treatment of anaerobic gram-negative infections. Aminopenicillins with β-lactamase-inhibitor combinations and imipenem were active for this agent. Desulfovibrio desulfuricans was β-lactamase producer and resistant to cephalosporins, while metronidazole, imipenem and levofloxacin were active. A reliable identification of these microorganisms is important for establishing the best therapeutic scheme.
Topics: Anaerobiospirillum; Anti-Bacterial Agents; Bacteremia; Desulfovibrio desulfuricans; Gram-Negative Bacterial Infections; Humans; Immunocompromised Host
PubMed: 28506633
DOI: 10.1016/j.ram.2016.12.008 -
Journal of Bacteriology Mar 1966Alico, Robert K. (St. Bonaventure University, St. Bonaventure, N.Y.), and Francis W. Liegey. Growth of Desulfovibrio desulfuricans, under heterotrophic and anaerobic...
Alico, Robert K. (St. Bonaventure University, St. Bonaventure, N.Y.), and Francis W. Liegey. Growth of Desulfovibrio desulfuricans, under heterotrophic and anaerobic conditions. J. Bacteriol. 91:1112-1114. 1966.-Growth of Desulfovibrio desulfuricans was investigated under heterotrophic and anaerobic conditions. For initial growth to occur, it was found that the E(h) or redox potential must be at least 0 mv. Some carbon sources were tested, and those which could be metabolized by D. desulfuricans were pyruvate, lactate, glycerol, glyceraldehyde, and ribose. Observations were also made on the sulfate used during growth. Various amounts of sulfate were added and depleted within 48 hr. This may be correlated with the decline in growth. As the terminal electron acceptor was exhausted the organisms could not respire, and, with the subsequent energy depletion, the population decreased.
Topics: Desulfovibrio; Electron Transport; Glyceraldehyde; Glycerol; In Vitro Techniques; Lactates; Oxidation-Reduction; Pyruvates; Ribose; Sulfates
PubMed: 5929745
DOI: 10.1128/jb.91.3.1112-1114.1966