scholarly journals Vitroprocines, new antibiotics against Acinetobacter baumannii, discovered from marine Vibrio sp. QWI-06 using mass-spectrometry-based metabolomics approach

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Chih-Chuang Liaw ◽  
Pei-Chin Chen ◽  
Chao-Jen Shih ◽  
Sung-Pin Tseng ◽  
Ying-Mi Lai ◽  
...  
1993 ◽  
Vol 38 (5) ◽  
pp. 1091-1097 ◽  
Author(s):  
Margo G. Haygood ◽  
Pamela D. Holt ◽  
Alison Butler

2018 ◽  
Vol 57 (3) ◽  
Author(s):  
Lisa M. Leung ◽  
Christi L. McElheny ◽  
Francesca M. Gardner ◽  
Courtney E. Chandler ◽  
Sarah L. Bowler ◽  
...  

ABSTRACT Acinetobacter baumannii is a prevalent nosocomial pathogen with a high incidence of multidrug resistance. Treatment of infections due to this organism with colistin, a last-resort antibiotic of the polymyxin class, can result in the emergence of colistin-resistant strains. Colistin resistance primarily occurs via modifications of the terminal phosphate moieties of lipopolysaccharide-derived lipid A, which reduces overall membrane electronegativity. These modifications are readily identified by mass spectrometry (MS). In this study, we prospectively collected Acinetobacter baumannii complex clinical isolates from a hospital system in Pennsylvania over a 3-year period. All isolates were evaluated for colistin resistance using standard MIC testing by both agar dilution and broth microdilution, as well as genospecies identification and lipid A profiling using MS analyses. Overall, an excellent correlation between colistin susceptibility and resistance, determined by MIC testing, and the presence of a lipid A modification, determined by MS, was observed with a sensitivity of 92.9% and a specificity of 94.0%. Additionally, glycolipid profiling was able to differentiate A. baumannii complex organisms based on their membrane lipids. With the growth of MS use in clinical laboratories, a reliable MS-based glycolipid phenotyping method that identifies colistin resistance in A. baumannii complex clinical isolates, as well as other Gram-negative organisms, represents an alternative or complementary approach to existing diagnostics.


1976 ◽  
Vol 22 (10) ◽  
pp. 1443-1452 ◽  
Author(s):  
M. Maeda ◽  
N. Taga

Extracellular nuclease produced by a marine Vibrio sp., strain No. 2, was purified by salting out with ammonium sulfate and by chromatography on a DEAE-cellulose column and twice on a Sephadex G-200 column. The nuclease was eluted as a single peak in which the deoxyribonuclease (DNase) activity and ribonuclease (RNase) activity appeared together. Polyacrylamide disc gel electrophoresis showed a single band of stained protein which had both DNase and RNase activity. The molecular weight of the enzyme was estimated to be 100 000 daltons. When using partially purified enzyme from the DEAE-cellulose column, the optimum pH for activity was 8.0, and the enzyme was activated strongly by 0.05 M Mg2+ ion and stabilized by 0.01 M Ca2+ ion. These concentrations of Mg2+ and Ca2+ ions are similar to those of the two cations in seawater. Indeed, the enzyme revealed high activity and strong stability when kept in seawater. The presence of particulate matter, such as cellulose powder, chitin powder, Hyflosupercel, Kaolin, and marine mud increased the stability of the enzyme. When the hydrostatic pressure was increased from 1 to 1000 atmospheres, the decrements of the enzyme activity were more pronounced at 30 and 40 °C than at 25 or 50 °C. The enzyme activity was restored after decompression to 1 atm at 30 °C.


2013 ◽  
Vol 37 (3) ◽  
pp. 575-584 ◽  
Author(s):  
Jiushun Zhou ◽  
Menghao Cai ◽  
Tao Jiang ◽  
Weiqiang Zhou ◽  
Wei Shen ◽  
...  

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