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Attention Score in Context
| Title |
The Capability of Tyramine Production and Correlation between Phenotypic and Genetic Characteristics of Enterococcus faecium and Enterococcus faecalis Strains
|
|---|---|
| Published in |
Frontiers in Microbiology, December 2015
|
| DOI | 10.3389/fmicb.2015.01371 |
| Pubmed ID | |
| Authors |
Eleonora Bargossi, Fausto Gardini, Veronica Gatto, Chiara Montanari, Sandra Torriani, Giulia Tabanelli |
| Abstract |
The aim of this study was to investigate the diversity of tyramine production capability of four Enterococcus strains in buffered systems in relation to their genetic characteristics and environmental conditions. Cells of the strains Enterococcus faecalis EF37 and ATCC 29212, and E. faecium FC12 and FC643 were re-suspended in phosphate/citrate buffers with different pH, NaCl concentration and incubation temperature. At intervals, cell viability and tyramine production were assessed by plate counting and HPLC analysis, respectively. The activity of a purified tyrosine decarboxylase (TDC) was determined under the same conditions, as a reference. Reduced loss in cell viability was observed in all the tested conditions, except for pH 4 after 24 h. The TDC activity was greatly heterogeneous within the enterococci: EF37 and FC12 produced the higher tyramine concentrations, ATCC 29212 showed a reduced decarboxylase activity, while EF643 did not accumulate detectable amounts of tyramine in all the conditions assayed. Among the considerate variables, temperature was the most influencing factor on tyramine accumulation for enterococcal cells. To further correlate the phenotypic and genetic characteristics of the enterococci, the TDC operon region carrying the genes tyrosine decarboxylase (tyrDC), tyrosine/tyramine permease (tyrP), and Na(+)/H(+) antiporter (nhaC-2) was amplified and sequenced. The genetic organization and nucleotide sequence of this operon region were highly conserved in the enterococcal strains of the same species. The heterogeneity in tyramine production found between the two E. faecalis strains could be ascribed to different regulation mechanisms not yet elucidated. On the contrary, a codon stop was identified in the translated tyrDC sequence of E. faecium FC643, supporting its inability to accumulate tyramine in the tested conditions. In addition, the presence of an additional putative tyrosine decarboxylase with different substrate specificity and genetic organization was noticed for the first time. Concluding, the high TDC activity heterogeneity within enterococci determined different accumulation of tyramine, depending on different genetic determinants, regulation mechanisms, and environmental factors. The present research contributes to elucidate the genetic characteristics of enterococcal strains and correlate specific mutations to their different strain-dependent tyraminogenic activity. |
X Demographics
The data shown below were collected from the profile of 1 X user who shared this research output. Click here to find out more about how the information was compiled.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Switzerland | 1 | 100% |
Demographic breakdown
| Type | Count | As % |
|---|---|---|
| Scientists | 1 | 100% |
Mendeley readers
The data shown below were compiled from readership statistics for 43 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Unknown | 43 | 100% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Student > Ph. D. Student | 9 | 21% |
| Student > Master | 4 | 9% |
| Student > Bachelor | 4 | 9% |
| Unspecified | 3 | 7% |
| Researcher | 3 | 7% |
| Other | 7 | 16% |
| Unknown | 13 | 30% |
| Readers by discipline | Count | As % |
|---|---|---|
| Agricultural and Biological Sciences | 12 | 28% |
| Biochemistry, Genetics and Molecular Biology | 5 | 12% |
| Unspecified | 3 | 7% |
| Immunology and Microbiology | 3 | 7% |
| Chemistry | 2 | 5% |
| Other | 6 | 14% |
| Unknown | 12 | 28% |
Attention Score in Context
This research output has an Altmetric Attention Score of 1. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 08 December 2015.
All research outputs
#20,297,343
of 22,834,308 outputs
Outputs from Frontiers in Microbiology
#22,414
of 24,813 outputs
Outputs of similar age
#326,059
of 388,741 outputs
Outputs of similar age from Frontiers in Microbiology
#333
of 400 outputs
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So far Altmetric has tracked 24,813 research outputs from this source. They typically receive a little more attention than average, with a mean Attention Score of 6.3. This one is in the 1st percentile – i.e., 1% of its peers scored the same or lower than it.
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