scholarly journals Analysis of Vancomycin-Resistant Enterococci in Hemato-Oncological Patients

Antibiotics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 785
Author(s):  
Kristýna Hricová ◽  
Taťána Štosová ◽  
Pavla Kučová ◽  
Kateřina Fišerová ◽  
Jan Bardoň ◽  
...  
Keyword(s):  
Surface Protein ◽  
Ionization Time ◽  
Flight Mass Spectrometry ◽  
Vancomycin Resistant Enterococci ◽  
Oncological Patients ◽  
Genes Encoding ◽  
Unique Restriction ◽  
Vancomycin Resistant ◽  
Relationship Of ◽  
The Relationship

Enterococci are important bacterial pathogens, and their significance is even greater in the case of vancomycin-resistant enterococci (VRE). The study analyzed the presence of VRE in the gastrointestinal tract (GIT) of hemato-oncological patients. Active screening using selective agars yielded VRE for phenotypic and genotypic analyses. Isolated strains were identified with MALDI-TOF MS, (Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry) their susceptibility to antibiotics was tested, and resistance genes (vanA, vanB, vanC-1, vanC2-C3) and genes encoding virulence factors (asa1, gelE, cylA, esp, hyl) were detected. Pulsed-field gel electrophoresis was used to assess the relationship of the isolated strains. Over a period of three years, 103 VanA-type VRE were identified in 1405 hemato-oncological patients. The most frequently detected virulence factor was extracellular surface protein (84%), followed by hyaluronidase (40%). Unique restriction profiles were observed in 33% of strains; clonality was detected in 67% of isolates. The study found that 7% of hemato-oncological patients carried VRE in their GIT. In all cases, the species identified was Enterococcus faecium. No clone persisted for the entire 3-year study period. However, genetically different clusters were observed for shorter periods of time, no longer than eight months, with identical VRE spreading among patients.

scholarly journals Biosynthesis of the Cyanobacterial Light-Harvesting Polypeptide Phycoerythrocyanin Holo-α Subunit in a Heterologous Host

2002 ◽  
Vol 184 (17) ◽  
pp. 4666-4671 ◽  
Author(s):  
Aaron J. Tooley ◽  
Alexander N. Glazer
Keyword(s):  
Ternary Complexes ◽  
Covalent Attachment ◽  
Heme Oxygenase 1 ◽  
Α Subunit ◽  
Ionization Time ◽  
E Coli ◽  
Metal Affinity ◽  
Flight Mass Spectrometry ◽  
Genes Encoding ◽  
Cyanobacterial Genes

ABSTRACT The entire pathway for the biosynthesis of the phycobiliviolin-bearing His-tagged holo-α subunit of the cyanobacterial photosynthetic accessory protein phycoerythrocyanin was reconstituted in Escherichia coli. Cyanobacterial genes encoding enzymes required for the conversion of heme to 3Z-phycocyanobilin, a precursor of phycobiliviolin (namely, heme oxygenase 1 and 3Z-phycocyanobilin:ferredoxin oxidoreductase), were expressed from a plasmid under the control of the hybrid trp-lac (trc) promoter. Genes for the apo-phycoerythrocyanin α subunit (pecA) and the heterodimeric lyase/isomerase (pecE and pecF), which catalyzes both the covalent attachment of phycocyanobilin and its concurrent isomerization to phycobiliviolin, were expressed from the trc promoter on a second plasmid. Upon induction, recombinant E. coli used endogenous heme to produce holo-PecA with absorbance and fluorescence properties similar to those of the same protein produced in cyanobacteria. About two-thirds of the apo-PecA was converted to holo-PecA. No significant bilin addition took place in a similarly engineered E. coli strain that lacks pecE and pecF. By using immobilized metal affinity chromatography, both apo-PecA and holo-PecA were isolated as ternary complexes with PecE and PecF. The identities of all three components in the ternary complexes were established unambiguously by protein and tryptic peptide analyses performed by matrix-assisted laser desorption ionization-time of flight mass spectrometry.

Identification of Sulfur Activation Relevant Protein Genes of Extremely Thermophilic Acidianus manzaensis

2017 ◽  
Vol 262 ◽  
pp. 461-465 ◽  
Author(s):  
Hong Chang Liu ◽  
Jin Lan Xia ◽  
Zhen Yuan Nie ◽  
Ya Long Ma ◽  
Yun Yang ◽  
...  
Keyword(s):  
Gel Electrophoresis ◽  
Elemental Sulfur ◽  
Extracellular Proteins ◽  
Laser Desorption Ionization ◽  
Two Dimensional Gel Electrophoresis ◽  
Ionization Time ◽  
Real Time Quantitative Pcr ◽  
Flight Mass Spectrometry ◽  
Genes Encoding ◽  
Acidianus Manzaensis

The sulfur activation by extracellular proteins is considered as the crucial stage during biooxidation of elemental sulfur (S0). In order to study genes encoding sulfur-activation related extracellular proteins of extremely thermophilic Acidianus manzaensis, the extracellular proteins with higher abundance for the strain grown on S0 allotropes than that on Fe2+ were first screened by two-dimensional gel electrophoresis, and then identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Nine genes amplified with PCR were satisfactory according to their agarose gel electrophoresis. The differential expression of these nine genes when the strain grown on S0 allotropes and Fe2+ were analyzed with real-time quantitative PCR (RT-qPCR). Results showed that seven of them were higher expressed when the strain grown on S0 allotropes than on Fe2+, indicating they may be related with sulfur activation by A. manzaensis.

Using Spectrum-Effect Relationships Coupled with LC–TOF–MS to Screen Anti-arrhythmic Components of the Total Flavonoids in Hypericum attenuatum Extracts

2020 ◽  
Author(s):  
Yufei Feng ◽  
Lin Teng ◽  
Yanli Wang ◽  
Yanyu Gao ◽  
Yuxuan Ma ◽  
...  
Keyword(s):  
Total Flavonoids ◽  
Universal Model ◽  
Bioactive Constituents ◽  
Flight Mass Spectrometry ◽  
Chemical Fingerprints ◽  
Relationship Of ◽  
The Relationship ◽  
Spectrum Effect ◽  
Tof Ms

Abstract This research explored the HPLC fingerprints of Hypericum attenuatum Choisy, which has anti-arrhythmic activity. HPLC was adopted to perform a determination of chemical fingerprints of H. attenuatum specimens acquired through seven distinct sources. The anti-arrhythmic activity of each H. attenuatum sample was obtained through pharmacodynamics experiments in animals. A regression analysis and correlation analysis were utilized to calculate the relationship of the peak and pharmacological effectiveness with the identified peak. Peaks numbered 5, 7, 13 and 14 in the fingerprint were regarded as the likely anti-arrhythmic agents. The fingerprint was compared with reference standards for identification of the correlative peaks. Liquid chromatography–time-of-flight–mass spectrometry was applied to identify its structure. As a consequence, a universal model was established for the utilization of HPLC to investigate anti-arrhythmic activity and the spectrum-effect relationship among H. attenuatum. This model is available for the discovery of the major bioactive constituents of Hypericum.

scholarly journals Molecular epidemiology of vancomycin-resistant Enterococcus faecium strains isolated from haematological malignancy patients in a research hospital in Turkey

2010 ◽  
Vol 59 (6) ◽  
pp. 660-664 ◽  
Author(s):  
S. Kirdar ◽  
A. G. Sener ◽  
U. Arslan ◽  
S. G. Yurtsever
Keyword(s):  
Enterococcus Faecium ◽  
Haematological Malignancy ◽  
Research Hospital ◽  
Vancomycin Resistant Enterococci ◽  
Time Period ◽  
Genes Encoding ◽  
Resistance Patterns ◽  
Training And Research ◽  
Vancomycin Resistant ◽  
Short Time

Infections and outbreaks of vancomycin-resistant enterococci (VRE) still appear to be rare in Turkey. In the present study, VRE strains isolated during an outbreak in a haematology unit of a training and research hospital in Turkey were typed and their antimicrobial-resistance patterns were characterized by molecular methods. Twelve vancomycin-resistant Enterococcus faecium strains isolated from patients with haematological malignancies were investigated by PCR for the presence of genes encoding resistance to vancomycin, tetracycline, chloramphenicol, gentamicin and erythromycin. Their clonal relationship was evaluated by PFGE and multilocus sequence typing. All strains were resistant to vancomycin and erythromycin, and had the vanA and ermB genes, respectively. PFGE was used to determine the presence of two pulsotypes and determine their subtypes. Pulsotype A belonged to sequence type (ST) 17 and pulsotype B belonged to ST 78. All strains with the vanA gene were not the same clone, indicating multiple acquisitions of resistant isolates, even over such a short time period.

scholarly journals High diversity of vancomycin-resistant Enterococcus faecium isolated in Southern Brazil

2019 ◽  
Author(s):  
Renata O Soares ◽  
Gabriela R Cunha ◽  
Vinicius P Perez ◽  
Jussara L Siqueira ◽  
Gustavo E Sambrano ◽  
...  
Keyword(s):  
Profile Analysis ◽  
Southern Brazil ◽  
Porto Alegre ◽  
Vancomycin Resistant Enterococci ◽  
Antimicrobial Susceptibility Profile ◽  
Vancomycin Resistant ◽  
Clonal Spread ◽  
High Level ◽  
Relationship Of ◽  
Level Resistance

Background. Vancomycin-resistant enterococci (VRE) are common in some hospital settings and their clonal spread has been described in different regions of the world. We determined the antimicrobial susceptibility profile and the clonal relationship of VRE isolates recovered from inpatients at three general hospitals of Porto Alegre, Brazil. Results. Ninety-four VRE were characterized as Enterococcus faecium and exhibited resistance to teicoplanin, ampicillin, ciprofloxacin, and susceptibility to linezolid, quinupristin-dalfopristin and daptomycin. High level resistance to gentamicin was detected in 13.8% of them. All VREfm harbored vanA gene, while 85.1% and 94.7% harbored respectively esp and acm virulence genes. PFGE profile analysis revealed 23 clonal types including 79 isolates, while 15 isolates exhibited unique pattern type, showing a polyclonal distribution of VREfm in Southern Brazil. Conclusion. These findings contribute to the local understanding regarding the characteristics of the circulating VREs in the region.

scholarly journals Detection of Volatiles from Raw Beef Meat from Different Packaging Systems Using Solid-Phase Microextraction GC–Accurate Mass Spectrometry

Foods ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2018
Author(s):  
Debarati Bhadury ◽  
Yada Nolvachai ◽  
Philip J. Marriott ◽  
Joanne Tanner ◽  
Kellie L. Tuck
Keyword(s):  
Mass Spectrometry ◽  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Carbon Disulphide ◽  
Accurate Mass ◽  
Flight Mass Spectrometry ◽  
Modified Atmospheric Packaging ◽  
Mass Quadrupole ◽  
Relationship Of ◽  
The Relationship

The volatile profile of raw beef contains vital information related to meat quality and freshness. This qualitative study examines the effect of packaging system on the formation and release of volatile organic compounds (VOCs) from raw beef over time, relative to the packaging best before date (BBD). The three packaging systems investigated were modified atmospheric packaging, vacuum packaging, and cling-wrapped packaging. Porterhouse steak samples with the same BBD were analysed from 3 days before to 3 days after the BBD. VOCs were detected via preconcentration using solid-phase microextraction combined with gas chromatography–accurate mass quadrupole time-of-flight mass spectrometry. In total, 35 different VOCs were tentatively identified. Interestingly, there was no clear relationship of the VOCs detected between the three packaging systems, with only carbon disulphide and acetoin, both known volatiles of beef, detected in all three. This is the first study to investigate the effects of commercial packaging systems on VOC formation; it provides an understanding of the relationship of VOCs to the BBD that is essential for the development of on-pack freshness and quality sensors.

scholarly journals SOURCES AND PATHWAYS OF SPREAD OF VANCOMYCIN-RESISTANT ENTEROCOCCI IN HEMATO-ONCOLOGICAL PATIENTS

2006 ◽  
Vol 150 (1) ◽  
pp. 117-120 ◽  
Author(s):  
Iva Vagnerova ◽  
Pavel Sauer ◽  
Milan Kolar ◽  
Sabina Slepickova ◽  
Jaromir Hubacek ◽  
...  
Keyword(s):  
Vancomycin Resistant Enterococci ◽  
Oncological Patients ◽  
Vancomycin Resistant

Prevalence, Antimicrobial Resistance, and Genotypic Characterization of Vancomycin-Resistant Enterococci in Meat Preparations

2016 ◽  
Vol 79 (5) ◽  
pp. 748-756 ◽  
Author(s):  
EMILIA GUERRERO-RAMOS ◽  
DIANA MOLINA-GONZÁLEZ ◽  
SONIA BLANCO-MORÁN ◽  
GILBERTO IGREJAS ◽  
PATRÍCIA POETA ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Virulence Determinants ◽  
Vancomycin Resistant Enterococci ◽  
Retail Outlets ◽  
Moderate Rate ◽  
Genes Encoding ◽  
Northwestern Spain ◽  
Vancomycin Resistant ◽  
Minced Meat

ABSTRACT A total of 160 samples of poultry (80), pork (40), and beef (40) preparations (red sausages, white sausages, hamburgers, meatballs, nuggets, minced meat, escalope, and crepes) were tested in northwestern Spain to determine the prevalence of vancomycin-resistant enterococci (VRE). VRE were detected in 38 (23.8%) samples (37.5% of poultry, 15.0% of pork, and 5.0% of beef samples). One strain per food sample was further characterized. Isolates were identified as Enterococcus faecium (14 strains), E. durans (10), E. hirae (7), E. gallinarum (5), and E. casseliflavus–E. flavescens (2). All strains showed resistance or intermediate susceptibility to three or more antimicrobials of clinical significance, in addition to vancomycin. High rates of resistance or intermediate susceptibility were observed for teicoplanin (81.6% of isolates), chloramphenicol (81.6%), erythromycin (100%), quinupristin-dalfopristin (89.5%), and ciprofloxacin (81.6%). A moderate rate of resistance or intermediate susceptibility emerged for ampicillin (34.2%) and tetracycline (36.8%). Genes encoding antimicrobial resistance and virulence were studied by PCR. The vanA, vanB, vanC-1, and vanC-2/3 genes were identified in 27, 1, 5, and 2 isolates, respectively. Other resistance genes or transposon sequences found were tet(L), tet(M), Tn5397 (tetracycline), erm(A), erm(B) (erythromycin), vat(D), and vat(E) (quinupristin-dalfopristin). Most isolates were free of virulence determinants (agg, hyl, and efaAfm genes were detected in one, one, and five strains, respectively). Strains were classified as not biofilm producers (crystal violet assay; 4 isolates) or weak biofilm producers (34 isolates). Cluster analysis (EcoRI ribotyping) suggested a strong genetic relationship among isolates from different types of meat preparations, animal species, and retail outlets. Meat preparations might play a role in the spread through the food chain of VRE with several resistance and virulence genes.

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