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Nefrologia : Publicacion Oficial de La... 2017
Topics: Humans; Male; Peritoneal Dialysis; Peritonitis; Pseudomonas Infections; Pseudomonas mendocina; Young Adult
PubMed: 28655401
DOI: 10.1016/j.nefro.2016.11.004 -
AMB Express Dec 2017Root exudates are chemical compounds that are released from living plant roots and provide significant energy, carbon, nitrogen and phosphorus sources for microbes...
Root exudates are chemical compounds that are released from living plant roots and provide significant energy, carbon, nitrogen and phosphorus sources for microbes inhabiting the rhizosphere. The exudates shape the microflora associated with the plant, as well as influences the plant health and productivity. Therefore, a better understanding of the trophic link that is established between the plant and the associated bacteria is necessary. In this study, a comprehensive survey on the utilization of grapevine and rootstock related organic acids were conducted on a vineyard soil isolate which is Pseudomonas mendocina strain S5.2. Phenotype microarray analysis has demonstrated that this strain can utilize several organic acids including lactic acid, succinic acid, malic acid, citric acid and fumaric acid as sole growth substrates. Complete genome analysis using single molecule real-time technology revealed that the genome consists of a 5,120,146 bp circular chromosome and a 252,328 bp megaplasmid. A series of genetic determinants associated with the carbon utilization signature of the strain were subsequently identified in the chromosome. Of note, the coexistence of genes encoding several iron-sulfur cluster independent isoenzymes in the genome indicated the importance of these enzymes in the events of iron deficiency. Synteny and comparative analysis have also unraveled the unique features of D-lactate dehydrogenase of strain S5.2 in the study. Collective information of this work has provided insights on the metabolic role of this strain in vineyard soil rhizosphere.
PubMed: 28655216
DOI: 10.1186/s13568-017-0437-7 -
Emerging Infectious Diseases Feb 2017We isolated IMP-19-producing Pseudomonas aeruginosa from 7 patients with nosocomial infections linked to contaminated sinks in France. We showed that bla was located on...
We isolated IMP-19-producing Pseudomonas aeruginosa from 7 patients with nosocomial infections linked to contaminated sinks in France. We showed that bla was located on various class 1 integrons among 8 species of gram-negative bacilli detected in sinks: P. aeruginosa, Achromobacter xylosoxidans, A. aegrifaciens, P. putida, Stenotrophomonas maltophilia, P. mendocina, Comamonas testosteroni, and Sphingomonas sp.
Topics: Cross Infection; Drug Resistance, Bacterial; France; Humans; Microbial Sensitivity Tests; Pseudomonas Infections; Pseudomonas aeruginosa; Water Microbiology; beta-Lactamase Inhibitors; beta-Lactamases
PubMed: 28098548
DOI: 10.3201/eid2302.160649 -
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 -
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 -
AMB Express Dec 2015Soluble arsenic (As) in acidic feed solution may inhibit the copper (Cu) bioleaching process within mine heaps. To clarify the effect of soluble arsenic on the live...
Soluble arsenic (As) in acidic feed solution may inhibit the copper (Cu) bioleaching process within mine heaps. To clarify the effect of soluble arsenic on the live biomass and bioxidative activity in heaps, toxicological assays were performed using a synthetic feed solution given by a mine company. The microorganisms had previously been isolated from two heap samples at up to 66 m depth, and cultured using specific media for chemolithotrophic acidophiles (pH 1-2) and moderate thermophiles (48°C), for arsenic tolerance assay. The four media with the highest biomass were selected to assay As-resistance; one culture (Q63h) was chosen to assay biooxidative activity, using a heap sample that contained chalcopyrite and covellite. We found that 0.5 g/L of As does not affect living biomass or biooxidative activity on Cu sulfides, but it dissolves Cu, while As precipitates as arsenic acid (H3AsO4·½H2O). The arsenic tolerant community, as identified by 16S rDNA gene sequence analysis, was composed of three main metabolic groups: chemolithotrophs (Leptospirillum, Sulfobacillus); chemolithoheterotrophs and organoheterotrophs as Acidovorax temperans, Pseudomonas alcaligenes, P. mendocina and Sphingomonas spp. Leptospirillum spp. and S. thermosulfidooxidans were the dominant taxa in the Q63-66 cultures from the deepest sample of the oldest, highest-temperature heap. The results indicated arsenic resistance in the microbial community, therefore specific primers were used to amplify ars (arsenic resistance system), aio (arsenite oxidase), or arr (arsenate respiratory reduction) genes from total sample DNA. Presence of arsB genes in S. thermosulfidooxidans in the Q63-66 cultures permits H3AsO4-As(V) detoxification and strengthens the community's response to As.
PubMed: 26283066
DOI: 10.1186/s13568-015-0132-5 -
BMC Genomics Apr 2015Phylogenetic heterogeneity across Pseudomonas genus is complemented by its diverse genome architecture enriched by accessory genetic elements (plasmids, transposons, and...
BACKGROUND
Phylogenetic heterogeneity across Pseudomonas genus is complemented by its diverse genome architecture enriched by accessory genetic elements (plasmids, transposons, and integrons) conferring resistance across this genus. Here, we sequenced a stress tolerant genotype i.e. Pseudomonas sp. strain RL isolated from a hexachlorocyclohexane (HCH) contaminated pond (45 mg of total HCH g(-1) sediment) and further compared its gene repertoire with 17 reference ecotypes belonging to P. stutzeri, P. mendocina, P. aeruginosa, P. psychrotolerans and P. denitrificans, representing metabolically diverse ecosystems (i.e. marine, clinical, and soil/sludge). Metagenomic data from HCH contaminated pond sediment and similar HCH contaminated sites were further used to analyze the pan-genome dynamics of Pseudomonas genotypes enriched across increasing HCH gradient.
RESULTS
Although strain RL demonstrated clear species demarcation (ANI ≤ 80.03%) from the rest of its phylogenetic relatives, it was found to be closest to P. stutzeri clade which was further complemented functionally. Comparative functional analysis elucidated strain specific enrichment of metabolic pathways like α-linoleic acid degradation and carbazole degradation in Pseudomonas sp. strain RL and P. stutzeri XLDN-R, respectively. Composition based methods (%codon bias and %G + C difference) further highlighted the significance of horizontal gene transfer (HGT) in evolution of nitrogen metabolism, two-component system (TCS) and methionine metabolism across the Pseudomonas genomes used in this study. An intact mobile class-I integron (3,552 bp) with a captured gene cassette encoding for dihydrofolate reductase (dhfra1) was detected in strain RL, distinctly demarcated from other integron harboring species (i.e. P. aeruginosa, P. stutzeri, and P. putida). Mobility of this integron was confirmed by its association with Tnp21-like transposon (95% identity) suggesting stress specific mobilization across HCH contaminated sites. Metagenomics data from pond sediment and recently surveyed HCH adulterated soils revealed the in situ enrichment of integron associated transposase gene (TnpA6100) across increasing HCH contamination (0.7 to 450 mg HCH g(-1) of soil).
CONCLUSIONS
Unlocking the potential of comparative genomics supplemented with metagenomics, we have attempted to resolve the environment and strain specific demarcations across 18 Pseudomonas gene complements. Pan-genome analyses of these strains indicate at astoundingly diverse metabolic strategies and provide genetic basis for the cosmopolitan existence of this taxon.
Topics: Base Sequence; Gene Transfer, Horizontal; Genome, Bacterial; Genotype; Hexachlorocyclohexane; Integrons; Metagenomics; Phylogeny; Pseudomonas; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Soil Microbiology; Water Microbiology; Water Pollutants, Chemical
PubMed: 25898829
DOI: 10.1186/s12864-015-1488-2