Summary of Study ST002868

This data is available at the NIH Common Fund's National Metabolomics Data Repository (NMDR) website, the Metabolomics Workbench, https://www.metabolomicsworkbench.org, where it has been assigned Project ID PR001791. The data can be accessed directly via it's Project DOI: 10.21228/M86M7M This work is supported by NIH grant, U2C- DK119886.

See: https://www.metabolomicsworkbench.org/about/howtocite.php

This study contains a large results data set and is not available in the mwTab file. It is only available for download via FTP as data file(s) here.

Study ID	ST002868
Study Title	Pathogenic Staphylococcus epidermidis ICE25 response to skin and blood pH
Study Summary	Staphylococcus epidermidis (SE) is one of the most common bacteria of the human skin microbiota. Despite its role as a commensal, SE has emerged as an opportunistic pathogen, associated with 80% of medical devices related infections. Moreover, these bacteria are extremely difficult to treat due to their ability to form biofilms and accumulate resistance to almost all classes of antimicrobials developed so far. Thus new preventive and therapeutic strategies are urgently needed. In spite of its clinical importance, the molecular mechanisms associated with SE colonisation and disease are still poorly understood. A deeper understanding of the metabolic and cellular processes associated with response to environmental factors characteristic of SE ecological niches in health and disease might provide new clues on colonisation and disease processes. Here we studied the impact of pH conditions, mimicking the skin pH (5.5) and blood pH (7.4), in a S. epidermidis pathogenic strain, belonging to the A/C clonal lineage, by means of next-generation proteomics and 1H NMR-based metabolomics. Moreover, we evaluated the metabolic changes occurring when a sudden pH change arise, simulating the skin barrier break produced by a catheter.
Institute	ITQB NOVA
Last Name	Gonçalves
First Name	Luís G.
Address	Avenida Republica
Email	lgafeira@itqb.unl.pt
Phone	214469464
Submit Date	2023-09-13
Raw Data Available	Yes
Raw Data File Type(s)	fid
Analysis Type Detail	NMR
Release Date	2024-01-02
Release Version	1

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Sample Preparation:

Sampleprep ID:	SP002986
Sampleprep Summary:	Cells were recovered at mid-exponential phase from 100 mL cultures following a protocol adapted from Somerville & Powers (Somerville and Powers 2014). Eight biological replicates of each independent growth condition were obtained. Cells were harvested by centrifugation at 5000 x g for 5 min at 4ºC. Cells were washed with 20 mM phosphate buffer pH 7.2-7.4 and centrifuged for 1 min at 13,000 rpm. Cell pellet was suspended in the same buffer with a final OD600 of 20 and stored at -80ºC for further metabolite extraction. Cells were thawed in a water bath at room temperature and 750 µL of 60% methanol were added and subjected to three freeze-thaw cycles using liquid nitrogen. Extracted samples were centrifuged at 21,000 g for 5 min at 4ºC. The extraction process on the pellets was repeated twice. The supernatants were kept and stored together at -20ºC overnight and dried in a SpeedVac. Dried samples were dissolved in: 750 µL phosphate buffer (33 mM, pH 7.0 in D2O with 2 mM of sodium azide) with 0.21 mM of 3-(trimethylsilyl)propionic-2,2,3,3-d4 (TSP). The suspensions were centrifuged at 21,000 g for 5 min at 4ºC and the resulting supernatants were then transferred to 5 mm NMR tubes.

Sampleprep ID:

SP002986

Sampleprep Summary:

Cells were recovered at mid-exponential phase from 100 mL cultures following a protocol adapted from Somerville & Powers (Somerville and Powers 2014). Eight biological replicates of each independent growth condition were obtained. Cells were harvested by centrifugation at 5000 x g for 5 min at 4ºC. Cells were washed with 20 mM phosphate buffer pH 7.2-7.4 and centrifuged for 1 min at 13,000 rpm. Cell pellet was suspended in the same buffer with a final OD600 of 20 and stored at -80ºC for further metabolite extraction. Cells were thawed in a water bath at room temperature and 750 µL of 60% methanol were added and subjected to three freeze-thaw cycles using liquid nitrogen. Extracted samples were centrifuged at 21,000 g for 5 min at 4ºC. The extraction process on the pellets was repeated twice. The supernatants were kept and stored together at -20ºC overnight and dried in a SpeedVac. Dried samples were dissolved in: 750 µL phosphate buffer (33 mM, pH 7.0 in D2O with 2 mM of sodium azide) with 0.21 mM of 3-(trimethylsilyl)propionic-2,2,3,3-d4 (TSP). The suspensions were centrifuged at 21,000 g for 5 min at 4ºC and the resulting supernatants were then transferred to 5 mm NMR tubes.