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Université de Fribourg

Rapid Detection of ESBL-Producing Enterobacteriaceae in Blood Cultures

Dortet, Laurent ; Poirel, Laurent ; Nordmann, Patrice

In: Emerging Infectious Diseases, 2015, vol. 21, no. 3, p. 504–507

We rapidly identified extended-spectrum β-lactamase (ESBL) producers prospectively among 245 gram-negative bacilli–positive cultured blood specimens using the Rapid ESBL Nordmann/Dortet/Poirel test and direct bacterial identification using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. This combination identified ESBL-producing Enterobacteriaceae within 30 min...

Université de Fribourg

Heterogeneous hydrolytic features for OXA-48-like β-lactamases

Oueslati, Saoussen ; Nordmann, Patrice ; Poirel, Laurent

In: Journal of Antimicrobial Chemotherapy, 2015, vol. 70, no. 4, p. 1059–1063

Objectives: Carbapenem-hydrolysing class D β-lactamases of the OXA-48 type are increasingly reported from Enterobacteriaceae. β-Lactamase OXA-48 hydrolyses penicillins very efficiently, but carbapenems only weakly and spares broad-spectrum cephalosporins. Recently, diverse OXA-48-like β-lactamases have been identified worldwide (OXA-162, OXA-181, OXA-163, OXA-204 and OXA-232). They differ by...

Université de Fribourg

The mgrB gene as a key target for acquired resistance to colistin in Klebsiella pneumoniae

Poirel, Laurent ; Jayol, Aurélie ; Bontron, Séverine ; Villegas, Maria-Virginia ; Ozdamar, Melda ; Türkoglu, Salih ; Nordmann, Patrice

In: Journal of Antimicrobial Chemotherapy, 2014, p. dku323

Objectives Alterations in the PhoPQ two-component regulatory system may be associated with colistin resistance in Klebsiella pneumoniae. MgrB is a small transmembrane protein produced upon activation of the PhoPQ signalling system, and acts as a negative regulator on this system. We investigated the role of the MgrB protein as a source of colistin resistance in a series of K. pneumoniae.Methods...

Université de Fribourg

Integration of the blaNDM-1 carbapenemase gene into Proteus genomic island 1 (PGI1-PmPEL) in a Proteus mirabilis clinical isolate

Girlich, Delphine ; Dortet, Laurent ; Poirel, Laurent ; Nordmann, Patrice

In: Journal of Antimicrobial Chemotherapy, 2014, p. dku371

Objectives To decipher the mechanisms and their associated genetic determinants responsible for β-lactam resistance in a Proteus mirabilis clinical isolate.Methods The entire genetic structure surrounding the β-lactam resistance genes was characterized by PCR, gene walking and DNA sequencing.Results Genes encoding the carbapenemase NDM-1 and the ESBL VEB-6 were located in a 38.5 kb MDR...

Université de Fribourg

Rapid detection of extended-spectrum-β-lactamase-producing Enterobacteriaceae from urine samples by use of the ESBL NDP test

Dortet, Laurent ; Poirel, Laurent ; Nordmann, Patrice

In: Journal of Clinical Microbiology, 2014, vol. 52, no. 10, p. 3701–3706

From June to September 2012, 500 urine samples were recovered from patients with urinary tract infections (UTI) due to Gram-negative bacilli (≥10⁴ leukocytes/ml and ≥10⁵ Gram-negative isolates/ml) who visited the University hospital Bicêtre (France). They were challenged with extended-spectrum-β-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-E) using the rapid diagnostic ESBL NDP...

Université de Fribourg

Resistance to colistin associated with a single amino acid change in protein PmrB among Klebsiella pneumoniae isolates of worldwide Origin

Jayol, Aurélie ; Poirel, Laurent ; Brink, Adrian ; Villegas, Maria-Virginia ; Yilmaz, Mesut ; Nordmann, Patrice

In: Antimicrobial Agents and Chemotherapy, 2014, vol. 58, no. 8, p. 4762–4766

A series of colistin-resistant Klebsiella pneumoniae isolates recovered from different countries was investigated in order to evaluate the involvement of the PmrA/PmrB two-component system in this resistance. Six isolates possessed a mutated PmrB protein, which is encoded by the pmrB gene, part of the pmrCAB operon involved in lipopolysaccharide modification. The same amino acid substitution...

Université de Fribourg

Multidrug-resistant Acinetobacter baumannii strains carrying the blaOxA-23 and the blaGES-11 genes in a neonatology center in Tunisia

Charfi-Kessis, Karama ; Mansour, Wejdene ; Khalifa, Anis Ben Haj ; Mastouri, Maha ; Nordmann, Patrice ; Aouni, Mahjoub ; Poirel, Laurent

In: Microbial Pathogenesis, 2014, vol. 74, p. 20–24

Multidrug-resistant and difficult-to-treat Acinetobacter baumannii may be responsible for nosocomial infections. The production of carbapenem-hydrolyzing class D β-lactamases (CHDLs) and extended-spectrum β-lactamase (ESBLs) of the GES type possessing a carbapenemase activity has been increasingly reported worldwide in A. baumannii. The aim of this study was to analyze the...

Université de Fribourg

The difficult-to-control spread of carbapenemase producers in Enterobacteriaceae worldwide

Nordmann, Patrice ; Poirel, Laurent

In: Clinical Microbiology and Infection, 2014, p. -

Spread of carbapenemase producers in Enterobacteriaceae is now identified worldwide. Three main carbapenemases are reported which belong to three classes of ß-lactamases that are KPC, NDM and OXA-48. The main reservoirs of KPC are Klebsiella pneumoniae in the USA, Israel, Greece and Italy, of NDM are K. pneumoniae and Escherichia coli in the Indian subcontinent, and of OXA-48 are K. pneumoniae...

Université de Fribourg

Characteristics of Escherichia coli sequence type 131 isolates that produce extended-spectrum β-lactamases: global distribution of the H30-Rx sublineage

Peirano, Gisele ; Bij, Akke K. van der ; Freeman, Joshua L. ; Poirel, Laurent ; Nordmann, Patrice ; Costello, Michael ; Tchesnokova, Veronika L. ; Pitout, Johann D. D.

In: Antimicrobial Agents and Chemotherapy, 2014, vol. 58, no. 7, p. 3762–3767

We designed a study to describe the characteristics of sequence type 131 (ST131) lineages, including the H30-Rx sublineage, among a global collection of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli isolates from 9 countries collected from 2000 to 2011. A total of 240 nonrepeat isolates from Canada, the United States, Brazil, the Netherlands, France, the United Arab...