Study Data


MS Study

Project uploaded by: Yashwant
Project ID: IMP_100044
Title: (p)ppGpp and DksA play crucial role in reducing the efficacy of ꞵ-lactam antibiotics by modulating bacterial membrane permeability
Project Description: The key signaling molecules in the bacterial stress sensing pathway, the alarmone (p)ppGpp and transcription factor DksA, help in survival during nutritional deprivation and exposure to xenobiotics by modulating cellular metabolic pathways. In Vibrio cholerae, (p)ppGpp metabolism is solely linked with the functions of three proteins: RelA, SpoT, and RelV. At threshold or elevated concentrations of (p)ppGpp, the level of cellular metabolites and proteins in the presence and absence of DksA in V. cholerae and other bacteria has not yet been comprehensively studied. We engineered the genome of V. cholerae to develop DksA null mutants in the presence and absence of (p)ppGpp biosynthetic enzymes. We observed a higher sensitivity of the (p)ppGpp0ΔdksA V. cholerae mutant to different ꞵ-lactam antibiotics compared to the wild-type (WT) strain. Our whole-cell metabolomic and proteome analysis revealed that the cell membrane and peptidoglycan biosynthesis pathways are significantly altered in the (p)ppGpp0, ΔdksA, and (p)ppGpp0ΔdksA V. cholerae strains. Further, the mutant strains displayed enhanced inner and outer membrane permeability in comparison to the WT strains. These results directly correlate with the tolerance and survival of V. cholerae to ꞵ-lactam antibiotics. These findings may help in the development of adjuvants for ꞵ-lactam antibiotics by inhibiting the functions of stringent response modulators.
Research Area: Biological Sciences
Funding Source: Translational Research Program (TRP) (No. BT/PR30159/MED/15/188/2018) of Department of Biotechnology (DBT), Govt. of India.
Project Contributors: Yashwant Kumar

Study uploaded by: Yashwant
Study ID: IMS_100038
Title: (p)ppGpp and DksA play crucial role in reducing the efficacy of ꞵ-lactam antibiotics by modulating bacterial membrane permeability
Summary: The key signaling molecules in the bacterial stress sensing pathway, the alarmone (p)ppGpp and transcription factor DksA, help in survival during nutritional deprivation and exposure to xenobiotics by modulating cellular metabolic pathways. In Vibrio cholerae, (p)ppGpp metabolism is solely linked with the functions of three proteins: RelA, SpoT, and RelV. At threshold or elevated concentrations of (p)ppGpp, the level of cellular metabolites and proteins in the presence and absence of DksA in V. cholerae and other bacteria has not yet been comprehensively studied. We engineered the genome of V. cholerae to develop DksA null mutants in the presence and absence of (p)ppGpp biosynthetic enzymes. We observed a higher sensitivity of the (p)ppGpp0ΔdksA V. cholerae mutant to different ꞵ-lactam antibiotics compared to the wild-type (WT) strain. Our whole-cell metabolomic and proteome analysis revealed that the cell membrane and peptidoglycan biosynthesis pathways are significantly altered in the (p)ppGpp0, ΔdksA, and (p)ppGpp0ΔdksA V. cholerae strains. Further, the mutant strains displayed enhanced inner and outer membrane permeability in comparison to the WT strains. These results directly correlate with the tolerance and survival of V. cholerae to ꞵ-lactam antibiotics. These findings may help in the development of adjuvants for ꞵ-lactam antibiotics by inhibiting the functions of stringent response modulators.
Publication:
Release Date: Aug. 13, 2025
Study Type: Mass Spectrometry (MS)
Data Type: Untargeted
IEC/IBSC Approval Number :

Sr.No Sample ID Sample Name Organism Source Sample Preparation Protocol Sample Type Experimental Condition Time of treatment Variant/Variety Gender Age Replicates Storage Conditions Extraction Protocol Number of files per sample
71 IMSM_102121 N16_5 Vibrio cholerae | 666 Bacteria The cells were pelleted down again by centrifugation (10,000 rpm at 4°C for 10 min), washed with 0.9% normal saline and stored at -80°C. To extract the intracellular metabolites cold 100% methanol was added (Sigma Aldrich; Cat no. 34860) followed by vortexing and bath sonication for 10 min (Bransonic® Ultrasonic M Cleaning Bath 1510). The cell debris was pelleted down by centrifugation (10,000 rpm at 4°C for 10 min) and supernatant was collected in two separate microcentrifuge tubes (120 µL each tube), vacuum dried (Thermo Scientific™ Savant™ SPD1010) and stored at -80°C. For the analysis of metabolites, the dried supernatant was dissolved in 60 µL of 15% methanol or 50% acetonitrile (Cat no. 271004) followed by vortexing for 5 min and centrifuged (10,000 rpm for 10 min). The supernatant was collected in a separate sample vial (Supelco™ Analytical). wild type Untreated overnight at 37°C NA NA NA NA –80ºC

The cells were pelleted down again by centrifugation (10,000 rpm at 4°C for 10 min), washed with 0.9% normal saline and stored at -80°C. To extract the intracellular metabolites cold 100% methanol was added (Sigma Aldrich; Cat no. 34860) followed by vortexing and bath sonication for 10 min (Bransonic® Ultrasonic M Cleaning Bath 1510). The cell debris was pelleted down by centrifugation (10,000 rpm at 4°C for 10 min) and supernatant was collected in two separate microcentrifuge tubes (120 µL each tube), vacuum dried (Thermo Scientific™ Savant™ SPD1010) and stored at -80°C. For the analysis of metabolites, the dried supernatant was dissolved in 60 µL of 15% methanol or 50% acetonitrile (Cat no. 271004) followed by vortexing for 5 min and centrifuged (10,000 rpm for 10 min). The supernatant was collected in a separate sample vial (Supelco™ Analytical).

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72 IMSM_102122 N16_6 Vibrio cholerae | 666 Bacteria The cells were pelleted down again by centrifugation (10,000 rpm at 4°C for 10 min), washed with 0.9% normal saline and stored at -80°C. To extract the intracellular metabolites cold 100% methanol was added (Sigma Aldrich; Cat no. 34860) followed by vortexing and bath sonication for 10 min (Bransonic® Ultrasonic M Cleaning Bath 1510). The cell debris was pelleted down by centrifugation (10,000 rpm at 4°C for 10 min) and supernatant was collected in two separate microcentrifuge tubes (120 µL each tube), vacuum dried (Thermo Scientific™ Savant™ SPD1010) and stored at -80°C. For the analysis of metabolites, the dried supernatant was dissolved in 60 µL of 15% methanol or 50% acetonitrile (Cat no. 271004) followed by vortexing for 5 min and centrifuged (10,000 rpm for 10 min). The supernatant was collected in a separate sample vial (Supelco™ Analytical). wild type Untreated overnight at 37°C NA NA NA NA –80ºC

The cells were pelleted down again by centrifugation (10,000 rpm at 4°C for 10 min), washed with 0.9% normal saline and stored at -80°C. To extract the intracellular metabolites cold 100% methanol was added (Sigma Aldrich; Cat no. 34860) followed by vortexing and bath sonication for 10 min (Bransonic® Ultrasonic M Cleaning Bath 1510). The cell debris was pelleted down by centrifugation (10,000 rpm at 4°C for 10 min) and supernatant was collected in two separate microcentrifuge tubes (120 µL each tube), vacuum dried (Thermo Scientific™ Savant™ SPD1010) and stored at -80°C. For the analysis of metabolites, the dried supernatant was dissolved in 60 µL of 15% methanol or 50% acetonitrile (Cat no. 271004) followed by vortexing for 5 min and centrifuged (10,000 rpm for 10 min). The supernatant was collected in a separate sample vial (Supelco™ Analytical).

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Sr.No MS Exp ID Sample Name/ID Mass Spectrometer Type MS Instrument Name MS Instrument type MS Ionization Method Ion Mode/Scan Polarity Data Transformation (Software/s Used)
91 IME_101363 JV8_1 / IMSM_102063 LCMS (Liquid Chromatography- Mass Spectrometry) Thermo Fusion Orbitrap Orbitrap Electrospray Ionization - ESI Negative NA
92 IME_101364 JV8_2 / IMSM_102064 LCMS (Liquid Chromatography- Mass Spectrometry) Thermo Fusion Orbitrap Orbitrap Electrospray Ionization - ESI Negative NA
93 IME_101365 JV8_3 / IMSM_102065 LCMS (Liquid Chromatography- Mass Spectrometry) Thermo Fusion Orbitrap Orbitrap Electrospray Ionization - ESI Negative NA
94 IME_101366 JV8_4 / IMSM_102066 LCMS (Liquid Chromatography- Mass Spectrometry) Thermo Fusion Orbitrap Orbitrap Electrospray Ionization - ESI Negative NA
95 IME_101367 JV8_5 / IMSM_102067 LCMS (Liquid Chromatography- Mass Spectrometry) Thermo Fusion Orbitrap Orbitrap Electrospray Ionization - ESI Negative NA
96 IME_101368 JV8_6 / IMSM_102068 LCMS (Liquid Chromatography- Mass Spectrometry) Thermo Fusion Orbitrap Orbitrap Electrospray Ionization - ESI Negative NA
97 IME_101369 JV9_1 / IMSM_102069 LCMS (Liquid Chromatography- Mass Spectrometry) Thermo Fusion Orbitrap Orbitrap Electrospray Ionization - ESI Negative NA
98 IME_101370 JV9_2 / IMSM_102070 LCMS (Liquid Chromatography- Mass Spectrometry) Thermo Fusion Orbitrap Orbitrap Electrospray Ionization - ESI Negative NA
99 IME_101371 JV9_3 / IMSM_102071 LCMS (Liquid Chromatography- Mass Spectrometry) Thermo Fusion Orbitrap Orbitrap Electrospray Ionization - ESI Negative NA
100 IME_101372 JV9_4 / IMSM_102072 LCMS (Liquid Chromatography- Mass Spectrometry) Thermo Fusion Orbitrap Orbitrap Electrospray Ionization - ESI Negative NA

Sr.No First name Last name Email Organization Designation
1 Yashwant Kumar y.kumar@thsti.res.in Translational Health Science And Technology Institute (THSTI) scientist

Sr.No ftprun ID MS Exp ID MS Data Files
11 IMR_101887 IME_101283 HILIC_NEG_JV8_5.mzXML
12 IMR_101888 IME_101284 HILIC_NEG_JV8_6.mzXML
13 IMR_101889 IME_101285 HILIC_NEG_JV9_1.mzXML
14 IMR_101890 IME_101286 HILIC_NEG_JV9_2.mzXML
15 IMR_101891 IME_101287 HILIC_NEG_JV9_3.mzXML
16 IMR_101892 IME_101288 HILIC_NEG_JV9_4.mzXML
17 IMR_101893 IME_101289 HILIC_NEG_JV9_5.mzXML
18 IMR_101894 IME_101290 HILIC_NEG_JV9_6.mzXML
19 IMR_101895 IME_101291 HILIC_NEG_MC3_1.mzXML
20 IMR_101896 IME_101292 HILIC_NEG_MC3_2.mzXML