scholarly journals Alteration of GyrA Amino Acid Required for Ciprofloxacin Resistance in Klebsiella pneumoniae Isolates in China

2008 ◽  
Vol 52 (8) ◽  
pp. 2980-2983 ◽  
Author(s):  
Yingmei Fu ◽  
Lishuang Guo ◽  
Yan Xu ◽  
Wenli Zhang ◽  
Jiaao Gu ◽  
...  
Keyword(s):  
Amino Acid ◽  
Klebsiella Pneumoniae ◽  
Published Data ◽  
Ciprofloxacin Resistance ◽  
Single Substitution

ABSTRACT Resistance to ciprofloxacin was detected in 111 (48.1%) isolates of Klebsiella pneumoniae from China. GyrA alterations were identified in the ciprofloxacin-resistant and ciprofloxacin-susceptible isolates. The results, including previously published data, indicate that the single substitution Ser83→Ile and three types of double mutations at Ser83 and Asp87 were required for ciprofloxacin resistance (P < 0.05).

scholarly journals Electron transfer to nitrogenase. Characterization of flavodoxin from Azotobacter chroococcum and comparison of its redox potentials with those of flavodoxins from Azotobacter vinelandii and Klebsiella pneumoniae (nifF-gene product)

1986 ◽  
Vol 239 (1) ◽  
pp. 69-75 ◽  
Author(s):  
J Deistung ◽  
R N F Thorneley
Keyword(s):  
Amino Acid ◽  
Klebsiella Pneumoniae ◽  
Gene Product ◽  
Azotobacter Vinelandii ◽  
Azotobacter Chroococcum ◽  
Amino Acid Sequences ◽  
Published Data ◽  
Redox Potentials ◽  
Hydrogen Electrode ◽  
Visible Spectra

Flavodoxin in the hydroquinone state acts as an electron donor to nitrogenase in several nitrogen-fixing organisms. The mid-point potentials for the oxidized-semiquinone and semiquinone-hydroquinone couples of flavodoxins isolated from facultative anaerobe Klebsiella pneumoniae (nifF-gene product, KpFld) and the obligate aerobe Azotobacter chroococcum (AcFld) were determined as a function of pH. The mid-point potentials of the semiquinone-hydroquinone couples of KpFld and AcFld are essentially independent of pH over the range pH 7-9, being -422 mV and -522 mV (normal hydrogen electrode) at pH 7.5 respectively. The mid-point potentials of the quinone-semiquinone couples at pH 7.5 are -200 mV (KpFld) and -133 mV (AcFld) with delta Em/pH of -65 +/- 4 mV (KpFld) and -55 +/- 2 mV (AcFld) over the range pH 7.0-9.5. This indicates that reduction of the quinone is coupled to protonation to yield a neutral semiquinone. The significance of these values with respect to electron transport to nitrogenase is discussed. The amino acid compositions, the N- and C-terminal amino acid sequences and the u.v.-visible spectra of KpFld and AcFld were determined and are compared with published data for flavodoxins isolated from Azotobacter vinelandii.

Corticosteroid Catabolism by Klebsiella pneumoniae as a Possible Mechanism for Increased Pneumonia Risk

2019 ◽  
Vol 20 (4) ◽  
pp. 309-316 ◽  
Author(s):  
Pritam Chattopadhyay ◽  
Goutam Banerjee
Keyword(s):  
Amino Acid ◽  
Klebsiella Pneumoniae ◽  
Kegg Pathway ◽  
Degradation Pathway ◽  
Amino Acid Sequences ◽  
Biological Mechanism ◽  
Clinical Strains ◽  
Catabolism Pathway ◽  
Steroid Catabolism ◽  
Nutrition Source

Background: Several strains of Klebsiella pneumoniae are responsible for causing pneumonia in lung and thereby causing death in immune-suppressed patients. In recent year, few investigations have reported the enhancement of K. pneumoniae population in patients using corticosteroid containing inhaler. Objectives: The biological mechanism(s) behind this increased incidence has not been elucidated. Therefore, the objective of this investigating was to explore the relation between Klebsiella pneumoniae and increment in carbapenamase producing Enterobacteriaceae score (ICS). Methods: The available genomes of K. pneumoniae and the amino acid sequences of steroid catabolism pathway enzymes were taken from NCBI database and KEGG pathway tagged with UniPort database, respectively. We have used different BLAST algorithms (tBLASTn, BLASTp, psiBLAST, and delBLAST) to identify enzymes (by their amino acid sequence) involved in steroid catabolism. Results: A total of 13 enzymes (taken from different bacterial candidates) responsible for corticosteroid degradation have been identified in the genome of K. pneumoniae. Finally, 8 enzymes (K. pneumoniae specific) were detected in four clinical strains of K. pneumoniae. This investigation intimates that this ability to catabolize corticosteroids could potentially be one mechanism behind the increased pneumonia incidence. Conclusion: The presence of corticosteroid catabolism enzymes in K. pneumoniae enhances the ability to utilize corticosteroid for their own nutrition source. This is the first report to demonstrate the corticosteroid degradation pathway in clinical strains of K. pneumoniae.

scholarly journals Amino Acid Substitutions of MagA in Klebsiella pneumoniae Affect the Biosynthesis of the Capsular Polysaccharide

PLoS ONE ◽  
2012 ◽  
Vol 7 (10) ◽  
pp. e46783 ◽  
Author(s):  
Tzu-Lung Lin ◽  
Feng-Ling Yang ◽  
An-Suei Yang ◽  
Hung-Pin Peng ◽  
Tsung-Lin Li ◽  
...  
Keyword(s):  
Amino Acid ◽  
Klebsiella Pneumoniae ◽  
Capsular Polysaccharide ◽  
Amino Acid Substitutions

scholarly journals The molybdenum–iron protein of Klebsiella pneumoniae nitrogenase. Evidence for non-identical subunits from peptide ‘mapping’

1976 ◽  
Vol 155 (2) ◽  
pp. 383-389 ◽  
Author(s):  
C Kennedy ◽  
R R. Eady ◽  
E Kondorosi ◽  
D K Rekosh
Keyword(s):  
Amino Acid ◽  
Klebsiella Pneumoniae ◽  
Sodium Dodecyl Sulphate ◽  
Azotobacter Vinelandii ◽  
Peptide Mapping ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Amino Acid Content ◽  
Rhizobium Japonicum ◽  
Fe Protein

The molybdenum- and iron-containing protein components of nitrogenase purified from Klebsiella pneumoniae, Azotobacter vinelandii, Azotobacter chroococcum and Rhizobium japonicum bacteroids all gave either one or two protein-staining bands after sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, depending on the commercial brand of sodium dodecyl sulphate used. The single band obtained with K. pneumoniae Mo-Fe protein when some commercial brands of sodium dodecyl sulphate were used in the preparation of the electrode buffer was resolved into two bands by the addition of 0.01% (v/v) dodecanol to the buffer. Protein extracted from the two bands obtained after electrophoresis of K. pneumoniae Mo-Fe protein gave unique and distinct peptide ‘maps’ after tryptic digestion. Undissociated Mo-Fe protein contained both sets of tryptic peptides. These data are consistent with Mo-Fe protein from K. pneumoniae being composed of non-identical subunits. Amino acid analyses of the subunit proteins revealed some clear differences in amino acid content, but the two subunits showed close compositional relatedness, with a different index [Metzer, H., Shapiro, M.B., Mosiman, J.E. & Vinton, J.G. (1968) Nature (London) 219, 1166-1168] of 4.7.

DETERMINATION OF PROTEIN SYNTHESIS IN RAINBOW TROUT, ONCORHYNCHUS MYKISS, USING A STABLE ISOTOPE

1994 ◽  
Vol 189 (1) ◽  
pp. 279-284
Author(s):  
C Carter ◽  
S Owen ◽  
Z He ◽  
P Watt ◽  
C Scrimgeour ◽  
...  
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Rainbow Trout ◽  
Amino Acid ◽  
Oncorhynchus Mykiss ◽  
Considerable Proportion ◽  
Published Data ◽  
Short Term ◽  
Terrestrial Mammals ◽  
Rainbow Trout Oncorhynchus Mykiss

It has been suggested (Houlihan, 1991) that the consumption of 1 g of protein in a variety of species of fish stimulates the synthesis of, approximately, an equal amount of protein. Although synthesis of protein may account for as much as 40 % of the whole-animal oxygen consumption (Lyndon et al. 1992), only about 30 % of the synthesized proteins are retained as growth (Houlihan et al. 1988; Carter et al. 1993a,b). Thus, one focus of attention is the potential advantage gained by fish in allocating a considerable proportion of assimilated energy to protein turnover in contrast to relatively low-cost, low-turnover protein growth (Houlihan et al. 1993). Rates of protein synthesis in several species of fish have been measured using radioactively labelled amino acids, frequently given as a flooding dose (reviewed by Fauconneau, 1985; Houlihan, 1991). These measurements cannot be made for longer than a few hours because of the decline in specific radioactivity in the amino acid free pool. However, as protein synthesis rates vary during the course of a day as a result of the post-prandial stimulation, and since radiolabelled amino acid methodology is invasive, short-term and terminal, it has been difficult to be certain of the relationship between protein growth measured in the long term and protein synthesis rates measured in the short term. This paper addresses these problems by developing a method using 15N in orally administered protein to measure protein synthesis rates in fish over relatively long periods, the aim being to use procedures that are as non-invasive and repeatable as possible. The use of stable isotopes to measure protein metabolism is well established in terrestrial mammals (see Rennie et al. 1991; Wolfe, 1992), but to our knowledge the only published data for aquatic ectotherms are on the blue mussel (Mytilus edulis L.) (Hawkins, 1985). In the present study, rates of protein synthesis of individual rainbow trout [Oncorhynchus mykiss (Walbaum)] were calculated from the enrichment of excreted ammonia with 15N over the 48 h following the feeding of a single meal (dose) containing protein uniformly labelled with 15N by use of an end-point stochastic model (Waterlow et al. 1978; Wolfe, 1992). Application of this type of modelling would appear to be ideal for measuring ammonotelic fish nitrogen metabolism since, unlike the situation in mammals, the catabolic flux of amino acids through urea is very small. Further, ammonia is excreted directly into the surrounding water via the gills and is not stored for any length of time, in contrast to the situation in mammals, so the rate of tracer appearance is easily measurable.

Effects of Antibiotic, Nicotine and Aminoacid starvation stresses on biofilm production in respiratory Klebsiella pneumoniae

2021 ◽  
Vol 30 (1) ◽  
pp. 61-69
Author(s):  
Rochell Davis and Paul D. Brown
Keyword(s):  
Amino Acid ◽  
Antimicrobial Resistance ◽  
Klebsiella Pneumoniae ◽  
Biofilm Formation ◽  
Genetic Relatedness ◽  
Amino Acid Starvation ◽  
Biofilm Production ◽  
Mar Index ◽  
Type 3 ◽  
Hospital Acquired

Background: Klebsiella pneumoniae is a major cause of hospital-acquired infections in Jamaica. Objective: We aimed to determine their antimicrobial resistance profiles and to assess biofilm formation in the presence of antibiotic, nicotine and amino acid starvation stresses. Methodology: Antimicrobial susceptibility and multiple antimicrobial resistance (MAR) index were determined for 23 K. pneumoniae strains. Biofilm production was evaluated in the presence of 50 μg/ml ceftazidime or gentamicin, 0–4 mg/ml nicotine, or 0.5 mg/ml serine hydroxamate (to induce amino acid starvation). Genetic relatedness, and the presence of type 3 fimbriae (mrkA) and determinants for extended spectrum β-lactamase and carbapenamases (bla-IMP, bla-VIM, bla-GIM and bla-SIM) were assessed by PCR-based amplification. Results: All strains were susceptible to imipenem (p<0.05); frequencies of resistance varied from 4% (for amikacin) and 8.7% (for meropenem) to over 30% for the other antimicrobials. About half of strains were resistant to ceftazidime, gentamicin and piperacillin. Mean MAR index was 0.31. The presence of antibiotics and nicotine at 2 and 4 mg/ml negatively affected biofilm formation for most strains. However, with amino acid starvation, almost 60% of strains retained medium or high biofilm production. Most strains harboured determinants for carbapenemase or metallo--lactamase, and one-third were PCRpositive for the OXA-1 gene. Strains were clustered into three groups based on ERICPCR analysis. Conclusion: These data suggest that certain antibiotics could inhibit biofilm production in K. pneumoniae even as multidrug resistance in this organism is evident. Further, this species has the propensity to harbour several genetic determinants for antimicrobial resistance.

scholarly journals Nonessential amino acid usage for protein replenishment in humans: a method of estimation

2019 ◽  
Vol 110 (2) ◽  
pp. 255-264 ◽  
Author(s):  
Paolo Tessari
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Protein Quality ◽  
Essential Amino Acids ◽  
World Health ◽  
Whole Body ◽  
Published Data ◽  
Total Proteins ◽  
Body Protein ◽  
Amino Acid Turnover

ABSTRACT Background Essential amino acids (EAAs) are key factors in determining dietary protein quality. Their RDAs have been estimated. However, although nonessential amino acids (NEAAs) are utilized for protein synthesis too, no estimates of their usage for body protein replenishment have been proposed so far. Objective The aim of this study was to provide minimum, approximate estimates of NEAA usage for body protein replenishment/conservation in humans. Methods A correlation between the pattern of both EAAs and NEAAs in body proteins, and their usage, was assumed. In order to reconstruct an “average” amino acid pattern/composition of total body proteins (as grams of amino acid per gram of protein), published data of relevant human organs/tissues (skeletal muscle, liver, kidney, gut, and collagen, making up ∼74% of total proteins) were retrieved. The (unknown) amino acid composition of residual proteins (∼26% of total proteins) was assumed to be the same as for the sum of the aforementioned organs excluding collagen. Using international EAA RDA values, an average ratio of EAA RDA to the calculated whole-body EAA composition was derived. This ratio was then used to back-calculate NEAA usage for protein replenishment. The data were calculated also using estimated organ/tissue amino acid turnover. Results The individual ratios of World Health Organization/Food and Agriculture Organization/United Nations University RDA to EAA content ranged between 1.35 (phenylalanine + tyrosine) and 3.68 (leucine), with a mean ± SD value of 2.72 ± 0.81. In a reference 70-kg subject, calculated NEAA usage for body protein replenishment ranged from 0.73 g/d for asparagine to 3.61 g/d for proline. Use of amino acid turnover data yielded similar results. Total NEAA usage for body protein replenishment was ∼19 g/d (45% of total NEAA intake), whereas ∼24 g/d was used for other routes. Conclusion This method may provide indirect minimum estimates of the usage of NEAAs for body protein replacement in humans.

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