Biology subjects

Dortet, L.

Publications and source records attributed to Dortet, L..

3 recordsLinked to original sources

bioRxiv2021

Breaking antimicrobial resistance by disrupting extracytoplasmic protein folding

Antimicrobial resistance in Gram-negative bacteria is one of the greatest threats to global health. New antibacterial strategies are urgently needed, and the development of antibiotic adjuvants that either neutralize resistance proteins or compromise the integrity of the cell envelope is of ever-growing interest. Most available adjuvants are only effective against specific resistance proteins. Here we demonstrate that disruption of cell envelope protein homeostasis simultaneously compromises several classes of resistance determinants. In particular, we find that impairing DsbA-mediated disulfide bond formation incapacitates diverse {beta}-lactamases and destabilizes mobile colistin resistance enzymes. Furthermore, we show that chemical inhibition of DsbA sensitizes multidrug-resistant clinical isolates to existing antibiotics and that the absence of DsbA, in combination with antibiotic treatment, substantially increases the survival of Galleria mellonella larvae infected with multidrug- resistant Pseudomonas aeruginosa. This work lays the foundation for the development of novel antibiotic adjuvants that function as broad-acting resistance breakers. IMPACT STATEMENTDisruption of disulfide bond formation sensitizes resistant Gram- negative bacteria expressing {beta}-lactamases and mobile colistin resistance enzymes to currently available antibiotics.

microbiology↗

bioRxiv2020

Rapid Detection of VanA/B-Producing Vancomycin-Resistant enterococci using Lateral Flow Immunoassay from colonies and blood culture

Vancomycin-resistant enterococci (VRE) have become one of the most important nosocomial pathogens worldwide associated with increased treatment costs, prolonged hospital stay, and high mortality. Rapid detection is crucial to reduce their spread and prevent infections and outbreaks. The lateral flow immunoassay NG-Test VanB (NG Biotech) was evaluated for the rapid detection of VanB-producing vancomycin-resistant enterococci (VanB-VRE) using 104 well-characterized enterococcal isolates. The sensitivity and specificity were both 100%, when bacterial cells were grown in the presence of vancomycin used as VanB inducer. The NG-Test VanB is an efficient, rapid, and easy to implement assay in clinical microbiology laboratories for the confirmation of VanB-VREs either from colonies or from positive blood cultures. Together with the NG-Test VanA, they could complete/replace the already existing panel of tests available for confirmation of acquired vancomycin resistance in enterococci, especially from selective media (rectal screenings) or from antibiograms (infections), with a sensitivity and specificity of both of 100%. The rapid detection in less than 15 minutes will result in more efficient management of carriers and infected patients.

microbiology↗

bioRxiv2019

Fast and robust detection of colistin resistance in Escherichia coli using the MALDI Biotyper Sirius mass spectrometry system

Polymyxin antibiotics are a last-line treatment for multidrug-resistant Gram-negative bacteria. However, the emergence of colistin resistance, including the spread of mobile mcr genes, necessitates the development of improved diagnostics for the detection of colistin-resistant organisms in hospital settings. The recently developed MALDIxin test enables detection of colistin resistance by MALDI-TOF mass spectrometry in less than 15 minutes but is not optimized for the mass spectrometers commonly found in clinical microbiology laboratories. In this study, we adapted the MALDIxin test for the MALDI Biotyper Sirius MALDI-TOF mass spectrometry system (Bruker Daltonics). We optimized the sample preparation protocol using a set of 6 MCR-expressing Escherichia coli clones and validated the assay with a collection of 40 E. coli clinical isolates, including 19 MCR producers, 12 chromosomally-resistant isolates and 9 polymyxin-susceptible isolates. We calculated Polymyxin resistance ratio (PRR) values from the acquired spectra; a PRR value of zero, indicating polymyxin susceptibility, was obtained for all colistin-susceptible E. coli isolates, whereas positive PRR values, indicating resistance to polymyxins, were obtained for all resistant strains independent of the genetic basis of resistance. Thus, we report a preliminary feasibility study showing that an optimized version of the MALDIxin test, adapted for the routine MALDI Biotyper Sirius, provides an unbiased, fast, reliable, cost-effective and high-throughput way of detecting colistin resistance in clinical E. coli isolates.

microbiology↗