ORCID Profile
0000-0002-7838-5145
Current Organisation
Indian Institute of Science
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Publisher: Cold Spring Harbor Laboratory
Date: 15-07-2020
DOI: 10.1101/2020.07.15.204859
Abstract: Salmonella is a genus of widely spread Gram negative, facultative anaerobic bacteria, which is known to cause ¼th of diarrheal morbidity and mortality globally. It causes typhoid fever and gastroenteritis by gaining access to the host gut through contaminated food and water. Salmonella utilizes its biofilm lifestyle to strongly resist antibiotics and persist in the host. Although biofilm removal or dispersal has been studied widely, the inhibition of the initiation of Salmonella biofilm remains elusive. This study was conducted to determine the anti-biofilm property of the cell-free supernatant obtained from a carbon-starvation inducible proline peptide transporter mutant (Δ yjiY) strain. Our study shows that Salmonella Δ yjiY culture supernatant primarily inhibits biofilm initiation by regulating biofilm-associated transcriptional network. This work demonstrates that highly abundant proteases such as HslV and GrpE cleave the protein aggregates, whereas global transcription regulators H-NS, FlgM regulate expression of SPIs and flagellar genes. Relatively low abundances of flavoredoxin, glutaredoxin, thiol peroxidase etc. leads to accumulation of ROS within the biofilm, and subsequent toxicity. This work further suggests that targeting these oxidative stress relieving proteins might be a good druggable choice to reduce Salmonella biofilm. The enteric pathogen Salmonella forms biofilm in the internal organs of asymptomatic carriers, and on abiotic surfaces that leads to contamination of food and water. Biofilms are highly drug-resistant life forms that also helps in host immune evasion. Therefore, recent insurgence of drug tolerant strains necessitates development of biofilm inhibitory strategies, and finding novel druggable targets. In this study we investigated the bioactive molecules present in the cell-free supernatant of a biofilm deficient strain of Salmonella Typhimurium that inhibit biofilm initiation by the wildtype strain. Further we showed that the supernatant treatment leads to virulence defect in vivo . Collectively, our results suggest a comprehensive view of virulence regulation in Salmonella by the cell-free supernatant of the biofilm deficient strain.
Publisher: Springer Science and Business Media LLC
Date: 10-12-2015
DOI: 10.1038/SREP17440
Abstract: Many bacteria secrete a highly hydrated framework of extracellular polymer matrix on suitable substrates and embed within the matrix to form a biofilm. Bacterial biofilms are observed on many medical devices, endocarditis, periodontitis and lung infections in cystic fibrosis patients. Bacteria in biofilm are protected from antibiotics and ,000 times of the minimum inhibitory concentration may be required to treat biofilm infections. Here, we demonstrated that shock waves could be used to remove Salmonella , Pseudomonas and Staphylococcus biofilms in urinary catheters. The studies were extended to a Pseudomonas chronic pneumonia lung infection and Staphylococcus skin suture infection model in mice. The biofilm infections in mice, treated with shock waves became susceptible to antibiotics, unlike untreated biofilms. Mice exposed to shock waves responded to ciprofloxacin treatment, while ciprofloxacin alone was ineffective in treating the infection. These results demonstrate for the first time that, shock waves, combined with antibiotic treatment can be used to treat biofilm infection on medical devices as well as in situ infections.
Publisher: Frontiers Media SA
Date: 03-12-2019
Publisher: Springer Science and Business Media LLC
Date: 08-01-2018
DOI: 10.1038/SREP46929
Abstract: Scientific Reports 5: Article number: 17440 published online: 10 December 2015 updated: 08 January 2018 Figure S6 in the Supplementary Information contains errors. Due to misfiling of data the figure was prepared incorrectly. The image in figure S6g corresponds to the incorrect experimental group:‘Mice infected with P.
Publisher: EMBO
Date: 11-05-2023
Abstract: The bacterial toxin CcdB (Controller of Cell death or ision B) targets DNA Gyrase, an essential bacterial topoisomerase, which is also the molecular target for fluoroquinolones. Here, we present a short cell‐penetrating 24‐mer peptide, CP1‐WT, derived from the Gyrase‐binding region of CcdB and examine its effect on growth of Escherichia coli , Salmonella Typhimurium, Staphylococcus aureus and a carbapenem‐ and tigecycline‐resistant strain of Acinetobacter baumannii in both axenic cultures and mouse models of infection. The CP1‐WT peptide shows significant improvement over ciprofloxacin in terms of its in vivo therapeutic efficacy in treating established infections of S. Typhimurium, S. aureus and A. baumannii . The molecular mechanism likely involves inhibition of Gyrase or Topoisomerase IV, depending on the strain used. The study validates the CcdB binding site on bacterial DNA Gyrase as a viable and alternative target to the fluoroquinolone binding site.
Publisher: Research Square Platform LLC
Date: 17-08-2020
DOI: 10.21203/RS.3.RS-54341/V1
Abstract: Salmonella is a genus of widely spread Gram negative, facultative anaerobic bacteria, which is known to cause ¼th of the diarrhoeal morbidity and mortality globally. It causes typhoid fever and gastroenteritis by gaining access to the host gut through contaminated food and water. Salmonella utilizes its biofilm lifestyle to strongly resist antibiotics and persist in the host. Although the biofilm removal or dispersal have been studied widely, the inhibition of initiation Salmonella biofilm has not been studied much. This study was conducted to determine the anti-biofilm property of the cell-free supernatant obtained from a carbon-starvation inducible proline peptide transporter mutant ( ΔyjiY ) strain. Our study shows that Salmonella ΔyjiY culture supernatant inhibits biofilm initiation by regulating biofilm associated transcriptional network. This work demonstrates that highly abundant proteases like ecotin, HslV and GrpE cleave the protein aggregates, whereas global transcription regulators H-NS, FlgM regulate expression of SPIs and flagellar genes. Relatively low abundance of flavoredoxin, glutaredoxin, thiol peroxidase etc. leads to accumulation of ROS within the biofilm, and subsequent toxicity. This work further suggests that targeting these oxidative stress relieving proteins might be a good druggable choice to reduce Salmonella biofilm.
Publisher: CRC Press
Date: 30-10-2017
Location: No location found
No related grants have been discovered for Dipshikha Chakravortty.