Rapid Detection of Bacterial Resistance by MALDI-TOF MS and Antibiotic Savings
Rapid Detection of Bacterial Resistance by MALDI-TOF MS and Antibiotic Savings
This study aims at determining within a short time (<3h) the susceptibility to clinical
 isolates of E. coli to the major antibiotics directly from positive blood cultures.
The resistance to antibiotic is a concern for the great majority of pathogenic bacteria. The
 proportion of antibiotic-resistant bacteria is particularly high in hospital settings. The
 accumulation of resistance mechanisms can lead to multidrug resistance, therapeutic impasses
 and a subsequent higher mortality of infected patients. The use of antibiotics in humans and
 animals creates a selection pressure that favors the dissemination of antibiotic resistant
 strains. It's necessary to optimize antibiotic consumption to limit the spread of these
 bacteria. It requires both the fast bacterial identification and the fast determination of
 their resistance profile in order to use narrower-spectrum compounds.

 Usually antibiotic susceptibility testing usually takes 18-24 hours. Mass Spectrometry type
 Matrix-Assisted Laser Desorption Ionization Time-Of-Flight (MALDI-TOF MS) has become a
 valuable tool in clinical laboratories for pathogen identification. Preliminary data showed
 that susceptible and resistant bacteria can be differentiated within 1 or 2 hours with a new
 technology called 'MS-ASTRA' based on a lower global peak intensity in the presence of the
 antibiotic of interest (at a concentration corresponding to the susceptibility breakpoint
 defined by the EUCAST) than in its absence. The objective of this study is to evaluate the
 performances of this new MALDI-TOF MS method on a panel of wild-type and resistant clinical
 isolates.

 This study aims to determine the resistance of Escherichia coli isolates to cefotaxime,
 piperacillin-tazobactam, amoxicillin and to implement the method to positive blood cultures.
 Minimal Inhibitory Concentrations will be determined the standard agar dilution method.

 Results and full analyze are deliverable within 2 years. The data obtained with the MS-ASTRA
 technique will be compared with the resistance status of the clinical isolates. The shortest
 incubation time (1 or 2 hours) that gives the more accurate result will be evaluate.The
 antibiotic savings that the implementation of this new method could have allowed will be
 evaluate.
Inclusion Criteria:

 -  All patients hospitalized in the hospital of Besançon, with a sepsis with E. coli.

 Exclusion Criteria:

 -  Patients without sepsis with E. coli