Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0519030 (Klebsiella)
 21,988 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

5-Phenyl/methyl-5-morpholinomethyl/pyrrolidinomethyl-2-(5- aryl-1,3,4-oxadiazol-2-yl)imino]-4-thiazolidinones (5a-m) were synthesized by the reaction of 5-phenyl/methyl-2-[(5-aryl-1,3,4-oxadiazol -2-yl)imino]-4-thiazolidinones (4a-j) with formaldehyde and morpholine or pyrrolidine. The structures of the compounds were determined by analytical and spectral (IR, 1H-NMR, EIMS) methods. The antibacterial activities of the novel compounds against Staphylococcus aureus ATCC 6538, Staphylococcus epidermidis ATCC 12228, Escherichia coli ATCC 8739, Klebsiella pneumoniae ATCC 4352, Pseudomonas aeruginosa ATCC 1539, Salmonella typhi, Shigella flexneri and Proteus mirabilis and antifungal activity against Candida albicans ATCC 10231 were tested using the disk diffusion method. Compounds 5a, 5b, 5c, 5e, 5g, and 5h were found to be active against S. aureus ATCC 6538 (MIC: 312.5; 39; 19.5; 39; 156; and 78 micrograms/mL respectively) and compounds 5c and 5h against S. flexneri (MIC: both 312.5 micrograms/mL). The minimal inhibitory concentrations of these compounds were determined using the micro dilution method.
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PMID:Synthesis of Mannich bases of some 2,5-disubstituted 4-thiazolidinones and evaluation of their antimicrobial activities. 1126 72

The potential of organic dust to induce inflammation in vitro can be viewed as a crude measure of the total biologically active compounds in a dust sample. The purpose of this study was to further develop an in vitro screening method for evaluation of potential hazard related to low doses of dust exposure using two monocytic cell lines (U937 and THP-1). Dust was obtained from schools in Copenhagen. U937 and THP-1 cells were stimulated with dust for 24 h and interleukin-8 secretion was measured. The initial slopes of the dose-response curves were used to calculate the inflammatory potential, or potency factor (PF), of the samples. In characterization of the method, lipopolysaccharide from Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Salmonella enteritidis were tested together with three glucans, nickel sulfate (NiSO(4)), methyl methacrylate (MMA), formaldehyde, and four surfactants. The PF values of LPSs in both monocytic assays ranked as follows: S. enteritidis> E. coli>K. pneumoniae/P. aeruginosa. The PF values of NiSO(4), MMA, formaldehyde, and the surfactants were zero or below. Using the THP-1 cell line, the PF values of dust samples were 30 times higher than when using the U937 cell line, and 7 times higher than when using the lung epithelial cell line (A549). The high sensitivity of the THP-1 bioassay makes it potentially useful as a screening tool for hazard evaluation of dust from, e.g., the indoor environment.
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PMID:Interleukin-8 secretion from monocytic cell lines for evaluation of the inflammatory potential of organic dust. 1205 97

In previous work, we found that an anaerobic sludge efficiently degraded hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), but the role of isolates in the degradation process was unknown. Recently, we isolated a facultatively anaerobic bacterium, identified as Klebsiella pneumoniae strain SCZ-1, using MIDI and the 16S rRNA method from this sludge and employed it to degrade RDX. Strain SCZ-1 degraded RDX to formaldehyde (HCHO), methanol (CH3OH) (12% of total C), carbon dioxide (CO(2)) (72% of total C), and nitrous oxide (N2O) (60% of total N) through intermediary formation of methylenedinitramine (O(2)NNHCH(2)NHNO(2)). Likewise, hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (MNX) was degraded to HCHO, CH3OH, and N2O (16.5%) with a removal rate (0.39 micromol. h(-1). g [dry weight] of cells(-1)) similar to that of RDX (0.41 micromol. h(-1). g [dry weight] of cells(-1)) (biomass, 0.91 g [dry weight] of cells. liter(-1)). These findings suggested the possible involvement of a common initial reaction, possibly denitration, followed by ring cleavage and decomposition in water. The trace amounts of MNX detected during RDX degradation and the trace amounts of hexahydro-1,3-dinitroso-5-nitro-1,3,5-triazine detected during MNX degradation suggested that another minor degradation pathway was also present that reduced -NO2 groups to the corresponding -NO groups.
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PMID:Biodegradation of hexahydro-1,3,5-trinitro-1,3,5-triazine and its mononitroso derivative hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine by Klebsiella pneumoniae strain SCZ-1 isolated from an anaerobic sludge. 1240 22

The authors examined the relationship between immune biomarkers and indoor air pollution cross-sectionally in school children 9-11 yr of age who had immunologically related respiratory diseases and who resided in Hungarian cities. Nitrogen dioxide, formaldehyde, benzene, xylene, and toluene were measured passively indoors prior to the collection of venous blood samples for blood counts and identification of immune biomarkers. House dust mite allergen was also measured. Numerous immune biomarkers were significantly elevated in these sensitive children, compared with normal children, and several biomarker alterations in these children were related to high concentrations of air pollutants in the home. The strongest and most significant associations were seen between high indoor nitrogen dioxide concentrations and increased white blood cells, monocytes, red blood cells, and immunoglobulin G (IgG), as well as decreased immunoglobulin M (IgM) and Klebsiella pneumoniae-specific IgM. Bacterial-specific IgGs were related significantly to formaldehyde concentrations. These findings suggest the important role of indoor air pollutants in immune reactions.
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PMID:Indoor air pollutants and immune biomarkers among Hungarian asthmatic children. 1499 8

Several H2-producing fermentative anaerobic bacteria including Clostridium, Klebsiella and Fusobacteria degraded octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) (36 microM) to formaldehyde (HCHO) and nitrous oxide (N2O) with rates ranging from 5 to 190 nmol h(-1)g [dry weight] of cells(-1). Among these strains, C. bifermentans strain HAW-1 grew and transformed HMX rapidly with the detection of the two key intermediates the mononitroso product and methylenedinitramine. Its cellular extract alone did not seem to degrade HMX appreciably, but degraded much faster in the presence of H2, NADH or NADPH. The disappearance of HMX was concurrent with the release of nitrite without the formation of the nitroso derivative(s). Results suggest that two types of enzymes were involved in HMX metabolism: one for denitration and the second for reduction to the nitroso derivative(s).
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PMID:Metabolism of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine by Clostridium bifermentans strain HAW-1 and several other H2-producing fermentative anaerobic bacteria. 1526 39

Over 18 months, enterobacteria were isolated from the raw (189 isolates) and treated (156 isolates) wastewater of a municipal treatment plant. The isolates were identified as members of the genera Escherichia (76%), Shigella (7%), Klebsiella (12%) and Acinetobacter (4%). Antimicrobial susceptibility phenotypes were determined using the agar diffusion method for the antibiotics amoxicillin, gentamicin, ciprofloxacin, sulfamethoxazole/trimethoprim, tetracycline and cephalothin, the disinfectants hydrogen peroxide, sodium hypochlorite, quaternary ammonium/formaldehyde and iodine, and the heavy metals nickel, cadmium, chromium, mercury and zinc. Class 1 integrons were detected by PCR amplification using the primers CS5 and CS3. Compared with the raw influent, the treated wastewater presented higher relative proportions of Escherichia spp. isolates resistant to ciprofloxacin and cephalothin (P<0.0001 and P<0.05, respectively). Except for mercury, which showed a positive correlation with tetracycline and sulfamethoxazole/trimethoprim, no significant positive correlations were observed between antibiotic, disinfectant and heavy metal resistance. The variable regions of class 1 integrons, detected in c. 10% of the Escherichia spp. isolates, contained predominantly the gene cassettes aadA1/dhfrI.
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PMID:Antimicrobial resistance patterns in Enterobacteriaceae isolated from an urban wastewater treatment plant. 1725 Jul 54

Serine hydroxymethyltransferase (SHMT) in the form of crude extract from a recombinant strain of Klebsiella aerogenes was used for the production of L-serine from glycine and formaldehyde (HCHO). A stirred tank bio-reactor with a continuous feed of HCHO (37%) was employed. Since the performance of the serine bioreactor was heavily dependent on how HCHO was fed, an automatic feedback control system was developed for HCHO delivery utilizing the phenomenon of formol titration. This control procedure was based on the following circumstance: as a bioconversion proceeded, if the rate of HCHO feed was balanced by the rate of serine synthesis so that HCHO concentration was maintained near zero, then there was no pH change in the bioreactor. Once the rate of HCHO addition exceeded that of serine synthesis, the HCHO concentration built up and the excess HCHO reacted with the amino group of an amino acid (e.g. glycine or serine) to produce a Schiff base and a proton which lowered the pH. A pH controller detected and relayed this pH change to the on-off switch of the HCHO feed pump. Thus, HCHO infusion stopped when the pH was lower than the set point, which was the initial pH of the reaction. With this control system, the maximum concentration of HCHO that was reached in the bioreactor was only 1mM-3.3mM depending on the pH and amino acid composition in the bioreactor. Moreover, a decrease in pH also signaled the use of a slower feed rate at which HCHO was to be, delivered once the pH resumed its initial value after excess HCHO was consumed by the reaction. Employing this control system, we have optimized the performance of the serine bioreactor to give a serine titer of 450 g/L with an 88% molar conversion of glycine at a volumetric serine productivity of 8.9 g/L/h.
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PMID:Enzymatic production of L-serine with a feedback control system for formaldehyde addition. 1855 68

Serine hydroxymethyltransferase (SHMT) in the form of crude extract form a recombinant strain of Klebsiella aerogenes was used to study the production of L-serine from glycine and formaldehyde (HCHO). SHMT activity linearly increased with temperature (30-50 degrees C). Addition of exogenous cofactors, tetrahydrofolic acid and pyridoxal-phosphate, significantly increased SHMT activity. The pH optimum of the SHMT catalyzed L-serine synthesis step was between 8.0 and 8.5. The K(m) for glycine was 11.6mM at 37 degrees C and pH 8.0. A 87% molar conversion of glycine to serine was obtained at equilibrium (37 degrees C, pH 8.0). Tetrahydrofolic acid was stabilized by maintaining the redox potential of the reaction solution below -330 mV through the addition of a reducing reagent such as beta-mercaptoethanol. SHMT stability was very sensitive to HCHO concentration. By carefully balancing the HCHO feed rate against the enzymatic bioconversion rate in order to keep HCHO concentration low, a serine titer of 160 g/L was achieved, the residual glycine concentration was reduced to 40 g/L, a 70% molar conversion of glycine with quantitative yield was obtained, and the overall serine productivity was 5.2 g/L/h.
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PMID:Enzymatic production of L-serine. 1855 4

Methods for short-term BOD analysis (BOD(st)) based on ferricyanide mediator reduction have succeeded in overcoming some problems associated with the standard BOD test analysis (BOD(5)) such as long-term incubations (5 days), the need to dilute samples and low reproducibility. Here we present a bioassay where a Klebsiella pneumoniae environmental strain successfully reduces ferricyanide without de-aeration of the samples with linear BOD(5) ranges between 30 and 500 mg L(-1) or 30 and 200 mg L(-1), using glucose-glutamic acid solution (GGA) or OECD standards respectively. We further propose a new assay termination solution that allows higher reproducibility and standardization of the cell-based assay, employing formaldehyde (22.7 g L(-1)) or other compounds in order to stop ferricyanide reduction without affecting the amperometric detection and therefore replace the centrifugation step normally used to stop microbial-driven reactions in ferricyanide-mediated bioassays. These improvements led to an accurate determination of real municipal wastewater samples.
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PMID:Assessing the effect of oxygen and microbial inhibitors to optimize ferricyanide-mediated BOD assay. 2164 25

Ideally, invading bacteria are detected as early as possible in critically ill patients: the strain of morbific pathogens is identified rapidly, and antimicrobial sensitivity is known well before the start of new antimicrobial therapy. Bacteria have a distinct metabolism, part of which results in the production of bacteria-specific volatile organic compounds (VOCs), which might be used for diagnostic purposes. Volatile metabolites can be investigated directly in exhaled air, allowing for noninvasive monitoring. The aim of this review is to provide an overview of VOCs produced by the six most abundant and pathogenic bacteria in sepsis, including Staphylococcus aureus, Streptococcus pneumoniae, Enterococcus faecalis, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli. Such VOCs could be used as biological markers in the diagnostic approach of critically ill patients. A systematic review of existing literature revealed 31 articles. All six bacteria of interest produce isopentanol, formaldehyde, methyl mercaptan, and trimethylamine. Since humans do not produce these VOCs, they could serve as biological markers for presence of these pathogens. The following volatile biomarkers were found for identification of specific strains: isovaleric acid and 2-methyl-butanal for Staphylococcus aureus; 1-undecene, 2,4-dimethyl-1-heptane, 2-butanone, 4-methyl-quinazoline, hydrogen cyanide, and methyl thiocyanide for Pseudomonas aeruginosa; and methanol, pentanol, ethyl acetate, and indole for Escherichia coli. Notably, several factors that may effect VOC production were not controlled for, including used culture media, bacterial growth phase, and genomic variation within bacterial strains. In conclusion, VOCs produced by bacteria may serve as biological markers for their presence. Goal-targeted studies should be performed to identify potential sets of volatile biological markers and evaluate the diagnostic accuracy of these markers in critically ill patients.
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PMID:Volatile metabolites of pathogens: a systematic review. 2367 95


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