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Journal of Medical Case Reports Oct 2016Gram-negative microorganisms are uncommon pathogens responsible for infective endocarditis. Pseudomonas mendocina, a Gram-negative water-borne and soil-borne bacterium,...
BACKGROUND
Gram-negative microorganisms are uncommon pathogens responsible for infective endocarditis. Pseudomonas mendocina, a Gram-negative water-borne and soil-borne bacterium, was first reported to cause human infection in 1992. Since then, it has rarely been reported as a human pathogen in the literature. We describe the first case of native valve infective endocarditis due to P. mendocina in the USA.
CASE PRESENTATION
A 57-year-old white man presented with bilateral large leg ulcers, fever, and marked leukocytosis. His past medical history included gout and chronic alcohol use. P. mendocina was isolated from his blood cultures. A comprehensive review of P. mendocina infection in the literature was performed. A total of eight cases of P. mendocina infection were reported in the literature. More than two-thirds of the cases of P. mendocina septicemia were associated with native valve infective endocarditis. Thus, an echocardiogram was performed and demonstrated mitral valve endocarditis with mild mitral insufficiency. His leg wounds were debrided and were probably the source of P. mendocina bacteremia. Unlike Pseudomonas aeruginosa, P. mendocina is susceptible to third-generation cephalosporins. Our patient received a 6-week course of antimicrobial therapy with a favorable clinical outcome.
CONCLUSIONS
Our reported case and literature review illuminates a rare bacterial cause of infective endocarditis secondary to P. mendocina pathogen. Native cardiac valves were affected in all reported cases of infective endocarditis, and a majority of affected heart valves were left-sided. The antibiotics active against P. mendocina are different from those that are active against P. aeruginosa, and they notably include third-generation cephalosporins. The outcome of all reported cases of P. mendocina was favorable and no mortality was described.
Topics: Anti-Bacterial Agents; Bandages; Debridement; Endocarditis, Bacterial; Heart Valve Diseases; Humans; Leg Ulcer; Male; Middle Aged; Pain; Penicillanic Acid; Piperacillin; Piperacillin, Tazobactam Drug Combination; Pseudomonas Infections; Pseudomonas mendocina; Treatment Outcome
PubMed: 27716406
DOI: 10.1186/s13256-016-1057-6 -
Bioengineered Sep 2016The straw can be degraded efficiently into humus by powerful enzymes from microorganisms, resulting in the accelerated circulation of N,P,K and other effective elements...
The straw can be degraded efficiently into humus by powerful enzymes from microorganisms, resulting in the accelerated circulation of N,P,K and other effective elements in ecological system. We isolated a strain through screening the straw degradation strains from natural humic straw in the low temperature area in northeast of china, which can produce cellulase efficiently. The strain was identified as Pseudomonas mendocina by using morphological, physiological, biochemical test, and molecular biological test, with the functional clarification on producing cellulase for Pseudomonas mendocina for the first time. The enzyme force constant Km and the maximum reaction rate (Vmax) of the strain were 0.3261 g/L and 0.1525 mg/(min.L) through the enzyme activity detection, and the molecular weight of the enzyme produced by the strain were 42.4 k and 20.4 k based on SDS-PAGE. The effects of various ecological factors such as temperature, pH and nematodes on the enzyme produced by the strain in the micro ecosystem in plant roots were evaluated. The result showed that the optimum temperature was 28°C, and the best pH was 7.4∼7.8, the impact heavy metal was Pb and the enzyme activity and biomass of Pseudomonas mendocina increased the movement and predation of nematodes.
Topics: Biomass; Cellulase; Enzyme Stability; Hydrogen-Ion Concentration; Metals, Heavy; Molecular Weight; Pseudomonas mendocina; Substrate Specificity; Temperature
PubMed: 27710430
DOI: 10.1080/21655979.2016.1227143 -
Chemistry & Biodiversity Aug 2016The biotransformations of cholic acid (1a), deoxycholic acid (1b), and hyodeoxycholic acid (1c) to bendigoles and other metabolites with bacteria isolated from the rural...
The biotransformations of cholic acid (1a), deoxycholic acid (1b), and hyodeoxycholic acid (1c) to bendigoles and other metabolites with bacteria isolated from the rural slaughterhouse of Cayambe (Pichincha Province, Ecuador) were reported. The more active strains were characterized, and belong to the genera Pseudomonas and Rhodococcus. Various biotransformation products were obtained depending on bacteria and substrates. Cholic acid (1a) afforded the 3-oxo and 3-oxo-4-ene derivatives 2a and 3a (45% and 45%, resp.) with P. mendocina ECS10, 3,12-dioxo-4-ene derivative 4a (60%) with Rh. erythropolis ECS25, and 9,10-secosteroid 6 (15%) with Rh. erythropolis ECS12. Bendigole F (5a) was obtained in 20% with P. fragi ECS22. Deoxycholic acid (1b) gave 3-oxo derivative 2b with P. prosekii ECS1 and Rh. erythropolis ECS25 (20% and 61%, resp.), while 3-oxo-4-ene derivative 3b was obtained with P. prosekii ECS1 and P. mendocina ECS10 (22% and 95%, resp.). Moreover, P. fragi ECS9 afforded bendigole A (8b; 80%). Finally, P. mendocina ECS10 biotransformed hyodeoxycholic acid (1c) to 3-oxo derivative 2c (50%) and Rh. erythropolis ECS12 to 6α-hydroxy-3-oxo-23,24-dinor-5β-cholan-22-oic acid (9c, 66%). Bendigole G (5c; 13%) with P. prosekii ECS1 and bendigole H (8c) with P. prosekii ECS1 and Rh. erythropolis ECS12 (20% and 16%, resp.) were obtained.
Topics: Abattoirs; Bile Acids and Salts; Ecuador; Hydroxysteroids; Molecular Conformation; Pseudomonas; Rhodococcus
PubMed: 27358241
DOI: 10.1002/cbdv.201500300 -
Applied Microbiology and Biotechnology Jul 2016Glucosylglycerols (GGs) are known as compatible solutes accumulated by some bacteria including cyanobacteria as well as higher plants for their adaptations to salt or... (Review)
Review
Glucosylglycerols (GGs) are known as compatible solutes accumulated by some bacteria including cyanobacteria as well as higher plants for their adaptations to salt or desiccation stresses. Since being identified in Japanese sake, their physiological effects and potential applications on human health cares have been explored in the following 15 years. Several different synthesis methods have been successively developed for the production of GGs. However, the efficiency of GG synthesis, especially biological synthesis, is still low. With the recent advances in genome sequencing and synthetic biology tools, systematical screening of enzyme candidates and metabolic engineering approaches is necessary for improving GG synthesis efficiency. In this review, we will summarize GG structure information, protective effects on human skin and digestive system as well as industrial enzymes, together with their synthesis by chemical, enzymatic, and biological in vivo approaches in detail, and provide some prospects on improving GG production.
Topics: Bacterial Proteins; Biodegradation, Environmental; Cell Membrane; Glucosides; Industrial Microbiology; Metabolic Engineering; Protein Engineering; Pseudomonas mendocina; Stenotrophomonas maltophilia; Stress, Physiological; Synechococcus; Xanthomonadaceae
PubMed: 27225470
DOI: 10.1007/s00253-016-7608-3 -
Journal of Biotechnology Aug 2016Pseudomonas pseudoalcaligenes CECT5344 tolerates cyanide and is also able to utilize cyanide and cyano-derivatives as a nitrogen source under alkaline conditions. The...
Pseudomonas pseudoalcaligenes CECT5344 tolerates cyanide and is also able to utilize cyanide and cyano-derivatives as a nitrogen source under alkaline conditions. The strain is considered as candidate for bioremediation of habitats contaminated with cyanide-containing liquid wastes. Information on the genome sequence of the strain CECT5344 became available previously. The P. pseudoalcaligenes CECT5344 genome was now resequenced by applying the single molecule, real-time (SMRT(®)) sequencing technique developed by Pacific Biosciences. The complete and finished genome sequence of the strain consists of a 4,696,984 bp chromosome featuring a GC-content of 62.34%. Comparative analyses between the new and previous versions of the P. pseudoalcaligenes CECT5344 genome sequence revealed additional regions in the new sequence that were missed in the older version. These additional regions mostly represent mobile genetic elements. Moreover, five additional genes predicted to play a role in sulfoxide reduction are present in the newly established genome sequence. The P. pseudoalcaligenes CECT5344 genome sequence is highly related to the genome sequences of different Pseudomonas mendocina strains. Approximately, 70% of all genes are shared between P. pseudoalcaligenes and P. mendocina. In contrast to P. mendocina, putative pathogenicity genes were not identified in the P. pseudoalcaligenes CECT5344 genome. P. pseudoalcaligenes CECT5344 possesses unique genes for nitrilases and mercury resistance proteins that are of importance for survival in habitats contaminated with cyano- and mercury compounds. As an additional feature of the SMRT sequencing technology, the methylome of P. pseudoalcaligenes was established. Six sequence motifs featuring methylated adenine residues (m6A) were identified in the genome. The genome encodes several methyltransferases, some of which may be considered for methylation of the m6A motifs identified. The complete genome sequence of the strain CECT5344 now provides the basis for exploitation of genetic features for biotechnological purposes.
Topics: Cyanides; DNA Methylation; DNA, Bacterial; Genome, Bacterial; Pseudomonas pseudoalcaligenes; Sequence Analysis, DNA
PubMed: 27060556
DOI: 10.1016/j.jbiotec.2016.04.008 -
Journal of Applied Microbiology Jul 2016Bacterial infection is a major challenge in wound care. Antimicrobial wound dressings are of great value for treating wound infections. Endolysins are evolving as a new...
AIMS
Bacterial infection is a major challenge in wound care. Antimicrobial wound dressings are of great value for treating wound infections. Endolysins are evolving as a new class of antimicrobials with multiple applications. This study describes the production and evaluation of T4 lysozyme (T4Lyz), product of gene e of the T4 bacteriophage, fused with Cellulose Binding Module (CBM) for facile immobilization to cellulosic wound dressing.
METHODS AND RESULTS
Genes encoding T4Lyz-CBM and T4Lyz were cloned and expressed in Escherichia coli and the enzymes were purified by cation exchange chromatography. While the CBM tag did not alter the optimum pH and stability features of T4Lyz, the lytic activity of the fusion protein was lowered. The bactericidal activity of T4Lyz-CBM, determined by viable count plating assay after 1 h incubation with Micrococcus lysodeikticus was 97·5% with 10 μg ml(-1) , and 99·96% and 95% for E. coli and Pseudomonas mendocina, respectively, with 200 μg ml(-1) enzyme. T4Lyz-CBM was immobilized to wound dressing gauze with a capacity of 5·5 μg mg(-1) matrix, whereas the unmodified T4Lyz did not exhibit any binding. The immobilized protein retained its bactericidal activity against Gram-positive and Gram-negative bacteria. Both free and immobilized T4Lyz-CBM, after heat denaturation, retained their bactericidal activities against Gram-negative bacteria only. The immobilized enzyme exhibited higher stability than the free enzyme when stored in dry form or in the presence of polyol stabilizers.
CONCLUSION
Tagging T4Lyz with CBM provides a facile, irreversible binding to cellulosic wound dressing while retaining its activity. This approach may be suitable even for other antimicrobial enzymes and -peptides.
SIGNIFICANCE AND IMPACT OF THE STUDY
The spread of antibiotic resistance requires innovative strategies for discovery and development of effective antimicrobial alternatives. This report presents a novel strategy for producing antimicrobial wound dressing materials.
Topics: Anti-Infective Agents; Bacteriophage T4; Bandages; Cellulose; Drug Resistance, Microbial; Enzyme Stability; Enzymes, Immobilized; Escherichia coli; Gram-Negative Bacteria; Gram-Positive Bacteria; Microbial Sensitivity Tests; Muramidase; Wound Infection
PubMed: 27028513
DOI: 10.1111/jam.13146 -
Bioscience, Biotechnology, and... Jul 2016Conditions for the optimal production of polyhydroxyalkanoate (PHA) by Pseudomonas mendocina PSU using a biodiesel liquid waste (BLW) were determined by response surface...
Conditions for the optimal production of polyhydroxyalkanoate (PHA) by Pseudomonas mendocina PSU using a biodiesel liquid waste (BLW) were determined by response surface methodology. These were an initial carbon to nitrogen ratio (C/N) of 40 (mole/mole), an initial pH of 7.0, and a temperature of 35 °C. A biomass and PHA concentration of 3.65 g/L and about 2.6 g/L (77% DCW), respectively, were achieved in a growth associated process using 20 g/L glycerol in the BLW after 36 h of exponential growth. The PHA monomer compositions were 3HB (3-hydroxybutyrate), a short-chain-length-PHA, and the medium-chain-length-PHA e.g. 3-hydroxyoctanoate and 3-hydroxydecanoate. Both the phbC and phaC genes were characterized. The phbC enzyme had not been previously detected in a Pseudomonas mendocina species. A 2.15 g/L of an exopolysaccharide, alginate, was also produced with a similar composition to that of other Pseudomonas species.
Topics: 3-Hydroxybutyric Acid; Alginates; Biodegradation, Environmental; Biofuels; Caprylates; Carbon; Decanoic Acids; Factor Analysis, Statistical; Gene Expression; Genes, Bacterial; Glucuronic Acid; Glycerol; Hexuronic Acids; Hydrogen-Ion Concentration; Industrial Waste; Nitrogen; Phylogeny; Polyhydroxyalkanoates; Pseudomonas mendocina; Temperature
PubMed: 26981955
DOI: 10.1080/09168451.2016.1158628 -
Biotechnology Letters Feb 2016To enhance the biosynthesis of medium-chain-length polyhydroxyalkanoates (PHAMCL) from glucose in Pseudomonas mendocina NK-01, metabolic engineering strategies were used...
OBJECTIVES
To enhance the biosynthesis of medium-chain-length polyhydroxyalkanoates (PHAMCL) from glucose in Pseudomonas mendocina NK-01, metabolic engineering strategies were used to block or enhance related pathways.
RESULTS
Pseudomonas mendocina NK-01 produces PHAMCL from glucose. Besides the alginate oligosaccharide biosynthetic pathway proved by our previous study, UDP-D-glucose and dTDP-L-rhamnose biosynthetic pathways were identified. These might compete for glucose with the PHAMCL biosynthesis. First, the alg operon, galU and rmlC gene were deleted one by one, resulting in NK-U-1(∆alg), NK-U-2 (∆alg∆galU), NK-U-3(alg∆galU∆rmlC). After fermentation for 36 h, the cell dry weight (CDW) and PHAMCL production of these strains were determined. Compared with NK-U: 1) NK-U-1 produced elevated CDW (from 3.19 ± 0.16 to 3.5 ± 0.11 g/l) and equal PHAMCL (from 0.78 ± 0.06 to 0.79 ± 0.07 g/l); 2) NK-U-2 produced more CDW (from 3.19 ± 0.16 to 3.55 ± 0.23 g/l) and PHAMCL (from 0.78 ± 0.06 to 1.05 ± 0.07 g/l); 3) CDW and PHAMCL dramatically decreased in NK-U-3 (1.53 ± 0.21 and 0.41 ± 0.09 g/l, respectively). Additionally, the phaG gene was overexpressed in strain NK-U-2. Although CDW of NK-U-2/phaG decreased to 1.29 ± 0.2 g/l, PHA titer (%CDW) significantly increased from 24.5 % up to 51.2 %.
CONCLUSION
The PHAMCL biosynthetic pathway was enhanced by blocking branched metabolic pathways in combination with overexpressing phaG gene.
Topics: Gene Expression; Gene Knockout Techniques; Glucose; Metabolic Engineering; Metabolic Networks and Pathways; Polyhydroxyalkanoates; Pseudomonas mendocina
PubMed: 26476529
DOI: 10.1007/s10529-015-1980-4 -
Water Environment Research : a Research... May 2015The extent of dehalogenation and degradation of toxic aromatic compounds in a nuclear wastewater was evaluated using a two-stage system consisting of a photolytic...
The extent of dehalogenation and degradation of toxic aromatic compounds in a nuclear wastewater was evaluated using a two-stage system consisting of a photolytic reactor followed by a biological reactor. Experiments were performed by varying the initial 4-chlorophenol (4-CP) concentration from 50 to 1000 mg/L. The UV pretreatment stage improved the overall efficiency of biodegradation of the recalcitrant compound by facilitating degradability in the biological stage. Removal efficiencies greater than 98% were achieved at 4-CP feed concentrations < 50 mg/L. Adding an H2O2 dose of 0.1 mg/L as an oxidant further improved biodegradation under optimum operating conditions for the entire system. Some known aromatic compound degraders such as Pseudomonas aeruginosa and Pseudomonas mendocina were detected in the consortium using the 16S rRNA genetic fingerprint technique. To the authors' knowledge, this is the first study on biodegradation of halogenated aromatic compounds that are copollutants of metallic radionuclides in radioactive wastewater.
Topics: Bacteria; Biomass; Bioreactors; Chlorophenols; Nuclear Reactors; Photochemistry; Phylogeny; Time Factors; Waste Disposal, Fluid; Wastewater; Water Pollutants, Chemical
PubMed: 26460459
DOI: 10.2175/106143015x14212658614117 -
Applied Biochemistry and Biotechnology Jan 2016Five bacterial strains were isolated from wastewater treatment facilities which were able to use furfural as the sole carbon source. Based on 16S rRNA phylogenetic...
Five bacterial strains were isolated from wastewater treatment facilities which were able to use furfural as the sole carbon source. Based on 16S rRNA phylogenetic analysis, these strains were identified as Cupriavidus pinatubonensis (designated ALS1280), Pigmentiphaga sp. (ALS1172), Pseudomonas sp. BWDY (ALS1279), Pseudomonas mendocina (ALS1131), and Pseudomonas putida (ALS1267). In all cases, growth under oxygenated conditions on furfural was accompanied by the transient accumulation of 2-furoic acid (furoate) with no furfuryl alcohol observed. ALS1267 and ALS1279 were also able to metabolize 5-(hydroxymethyl)furfural. The five isolates and their phylogenetic near neighbors were compared for furfural dehydrogenase activity and tolerance to furfural and furoate in defined and complex media. P. putida ALS1267 was the most tolerant to furans and tolerated 17 mM furfural or 195 mM furoate before its growth rate was reduced by 50 % in a defined medium. This strain also had the greatest specific growth rate on furfural (0.6/h at 27-30 °C) and showed the highest specific activity of furfural dehydrogenase (170 mIU/mg) of any furfural-utilizing strain that has been characterized to date.
Topics: Bacteria; Carbon; Furans; Microscopy, Electron, Scanning; Polysorbates
PubMed: 26419660
DOI: 10.1007/s12010-015-1859-9