Service de Bacteriologie Virologie

Le Kremlin-Bicêtre, France

Service de Bacteriologie Virologie

Le Kremlin-Bicêtre, France

Time filter

Source Type

Grosso F.,University of Porto | Quinteira S.,University of Porto | Poirel L.,Service de Bacteriologie Virologie | Novais A.,University of Porto | Peixe L.,University of Porto
Antimicrobial Agents and Chemotherapy | Year: 2012

The spread of OXA-24/OXA-40 (OXA-24/40)-producing Acinetobacter spp. in the Iberian Peninsula has been strongly influenced by clonal expansion, but the role of horizontal gene transfer has scarcely been explored. bla OXA-24/OXA-40-carrying plasmids and genetic environments were characterized in representative (n = 15) Acinetobacter species clinical isolates (obtained between 2001 and 2007) by Acinetobacter baumannii PCR-based replicon typing, sequencing, hybridization, and restriction fragment length polymorphism. Besides the identification of bla OXA-24/40 within the chromosomes of some isolates, the circulation of common bla OXA-24/40-carrying plasmids (30-kb repA-AB; 10-kb aci2) and genetic backbones among Acinetobacter spp. was demonstrated. Copyright © 2012, American Society for Microbiology. All Rights Reserved.


Poirel L.,Service de Bacteriologie Virologie | Castanheira M.,JMI Laboratories | Carrer A.,Service de Bacteriologie Virologie | Rodriguez C.P.,Service de Bacteriologie Virologie | And 2 more authors.
Antimicrobial Agents and Chemotherapy | Year: 2011

Two bla OXA-48-like-positive isolates (Klebsiella pneumoniae and Enterobacter cloacae) were recovered in Argentina in 2008 as part of a large-scale survey focused on multidrug resistance in Enterobacteriaceae. In both cases, sequencing identified β-lactamase OXA-163, differing from OXA-48 by a single amino substitution and a 4-amino-acid deletion. OXA-163 hydrolyzed penicillins, ceftazidime, and cefotaxime, whereas OXA-48 did not. However, OXA-163 had a much lower ability to hydrolyze carbapenems than OXA-48, therefore barely being considered a carbapenemase. In both isolates, the bla OXA-163 gene was located on plasmids that differed in structure and size. However, a detailed genetic analysis revealed a similar genetic context in those isolates, with the bla OXA-163 gene being bracketed by novel transposase genes, making this genetic environment different from that reported for the bla OXA-48 gene. This study identified the first class D β-lactamase compromising both extended-spectrum cephalosporin and carbapenem activities. Copyright © 2011, American Society for Microbiology. All Rights Reserved.


Poirel L.,Service de Bacteriologie Virologie | Revathi G.,Aga Khan University | Bernabeu S.,Service de Bacteriologie Virologie | Nordmann P.,Service de Bacteriologie Virologie
Antimicrobial Agents and Chemotherapy | Year: 2011

Seven carbapenem-resistant NDM-1-positive Klebsiella pneumoniae isolates were recovered from patients hospitalized between 2007 and 2009 in different wards at a referral and tertiary care center in Nairobi. Most of the isolates were obtained from urine. All isolates carried the bla NDM-1 carbapenemase gene previously reported from India, Pakistan, and the United Kingdom. These isolates were clonally related and expressed many other resistance determinants, including β-lactamases CTX-M-15, OXA-1, OXA-9, CMY-6, and aminoglycoside resistance methylase RmtC. This work corresponds to the first report of NDM-1 producers in Africa. Copyright © 2011, American Society for Microbiology. All Rights Reserved.


Girlich D.,Service de Bacteriologie Virologie | Poirel L.,Service de Bacteriologie Virologie | Nordmann P.,Service de Bacteriologie Virologie
Journal of Clinical Microbiology | Year: 2012

The modified Hodge test has an excellent sensitivity for detecting enterobacterial isolates producing Ambler class A (KPC) and class D (OXA-48) carbapenemases. Its sensitivity is low for NDM-1 producers (50%) but is increased to 85.7% by adding ZnSO 4 (100 μg/ml) in the culture medium. However, this test has a low specificity and is time-consuming. Copyright © 2012, American Society for Microbiology. All Rights Reserved.


Dortet L.,Service de Bacteriologie Virologie | Poirel L.,Service de Bacteriologie Virologie | Nordmann P.,Service de Bacteriologie Virologie
Journal of Clinical Microbiology | Year: 2012

A novel biochemical technique, the Carba NP test, has been evaluated to detect carbapenemase production in Pseudomonas spp. This test was specific (100%), sensitive (94.4%), and rapid (<2 h). This cost-effective test, which could be implemented in any microbiology laboratory, offers a reliable technique for identification of carbapenemase-producing Pseudomonas spp. Copyright © 2012, American Society for Microbiology. All Rights Reserved.


Cuzon G.,Service de Bacteriologie Virologie | Naas T.,Service de Bacteriologie Virologie | Villegas M.-V.,International Center for Medical Research and Training | Correa A.,International Center for Medical Research and Training | And 2 more authors.
Antimicrobial Agents and Chemotherapy | Year: 2011

Ten bla KPC-2-harboring Pseudomonas aeruginosa isolates from hospitals located in five different Colombian cities have been characterized. Isolates were multidrug resistant, belonged to five different pulsotypes, and possessed naturally chromosome-encoded bla AmpC and bla OXA-50 genes and the acquired bla KPC-2 gene. In most cases, the bla KPC-2 genes were carried by plasmids of different sizes and were associated with Tn4401b or a new structure containing only part of the Tn4401 sequence. This study revealed that several clones of P. aeruginosa producing bla KPC-2 are disseminating in Colombia. Copyright © 2011, American Society for Microbiology. All Rights Reserved.


Poirel L.,Service de Bacteriologie Virologie | Bonnin R.A.,Service de Bacteriologie Virologie | Nordmann P.,Service de Bacteriologie Virologie
Antimicrobial Agents and Chemotherapy | Year: 2011

The resistome of the multidrug-resistant Escherichia coli strain 271 carrying the plasmid-mediated blaNDM-1carbapenemase gene was analyzed by high-throughput genome sequencing. The p271A plasmid carrying the blaNDM-1 gene was 35.9 kb in size and possessed an IncN-type backbone that harbored a novel replicase gene. Acquisition of the blaNDM-1 gene on plasmid p271A had been likely the result of a cointegration event involving the transposase of Tn5403. The expression of blaNDM-1 was associated with the insertion sequence ISAba125 likely originating from Acinetobacter baumannii. E. coli 271 accumulated multiple resistance determinants, including five β-lactamase genes (comprising the extended-spectrum β-lactamase CTX-M-15), two 16S RNA methylase ArmA- and RmtB-encoding genes, and the qepA gene encoding an efflux pump involved in resistance to fluoroquinolones. These resistance genes were located on three additional plasmids, of 160 kb (IncA/C), 130 kb (IncF), and 110 kb (IncI1). In addition, several chromosomally encoded resistance determinants were identified, such as topoisomerase mutations, porin modifications and truncations, and the intrinsic ampC gene of E. coli that was weakly expressed. The multidrug resistance pattern observed for E. coli 271 was therefore the result of combined chromosome- and plasmid-encoded mechanisms. Copyright © 2011, American Society for Microbiology. All Rights Reserved.


Dortet L.,Service de Bacteriologie Virologie | Nordmann P.,Service de Bacteriologie Virologie | Poirel L.,Service de Bacteriologie Virologie
Antimicrobial Agents and Chemotherapy | Year: 2012

The carbapenemase NDM-1 has been identified recently in Enterobacteriaceae and Acinetobacter baumannii as a source of multidrug resistance, including resistance to carbapenems. By analyzing the immediate genetic environment of the bla NDM-1 carbapenemase gene among a series of NDM-1-producing enterobacterial isolates, a novel gene (ble MBL, for ble gene associated with the metallo-β-lactamase NDM-1) was identified. The ble MBL gene encodes a novel bleomycin resistance protein (BRP), named BRPMBL, that shares weak similarities with known BRPs (less than 60% amino acid identity). The expression of BRP MBL conferred resistance to bleomycin and to bleomycin-like molecules in Enterobacteriaceae and A. baumannii. The bla NDM-1 and bleMBL genes were coexpressed under the control of the same promoter, located upstream of the bla NDM-1 gene and at the extremity of the insertion sequence ISAba125. Most of the NDM producers possessed the ble MBL gene. Although BRP MBL did not modify the growth or death rates of Escherichia coli under experimental conditions, it suppressed the mutation rate of hypermutable E. coli and therefore may stabilize the plasmid-borne bla NDM-1 gene. This study suggests that the emerging carbapenemase NDM-1 is selected by bleomycin-like molecules, and that BRPMBL producers (and consequently NDM producers) are better suited to various environments. Copyright © 2012, American Society for Microbiology. All Rights Reserved.


Carrer A.,Service de Bacteriologie Virologie | Fortineau N.,Service de Bacteriologie Virologie | Nordmann P.,Service de Bacteriologie Virologie
Journal of Clinical Microbiology | Year: 2010

ChromID extended-spectrum β-lactamase (ESBL) culture medium is routinely used for screening ESBL producers. This medium was tested for detecting carbapenemase-producing Enterobacteriaceae isolates from a collection of reference strains and compared to the CHROMagar KPC culture medium previously evaluated for detecting KPC-producing isolates. Producers of IMP-, VIM-, and KPC-type carbapenemases with high levels of resistance to cephalosporins and to carbapenems were detected at 1 × 101 CFU/ml. The OXA-48 producers were not detected on ChromID ESBL medium unless coexpressing ESBLs, whereas carbapenemase-producing isolates with MICs of <4 μg/ml were not detected on CHROMagar KPC medium. Copyright © 2010, American Society for Microbiology. All Rights Reserved.


Nordmann P.,Service de Bacteriologie Virologie | Dortet L.,Service de Bacteriologie Virologie | Poirel L.,Service de Bacteriologie Virologie
Journal of Clinical Microbiology | Year: 2012

Enterobacterial strains producing clavulanic-acid-inhibited extended-spectrum β-lactamases (ESBLs) are increasingly reported worldwide. Conventional detection of ESBL production remains time-consuming (24 to 48 h). Therefore, the ESBL NDP (Nordmann/ Dortet/Poirel) test was developed for a rapid identification of ESBLs in Enterobacteriaceae. This biochemical test was based on the in vitro detection of a cephalosporin (cefotaxime) hydrolysis that is inhibited by tazobactam addition. The ESBL activity was evidenced by a color change (red to yellow) of a pH indicator (red phenol) due to carboxyl-acid formation resulting from cefotaxime hydrolysis that was reversed by addition of tazobactam (positive test). The ESBL NDP test was applied to cultured strains (215 ESBL producers and 40 ESBL nonproducers). Its sensitivity and specificity were 92.6% and 100%, respectively. Its sensitivity (100%) was excellent for detection of CTX-M producers. A few ESBL producers (n = 16) that remained susceptible to cefotaxime were not detected. The test was also evaluated on spiked blood cultures and showed excellent sensitivity and specificity (100% for both). The test was rapid (less than 1 h) and cost-effective. It can be implemented in any health care facility and is well adapted for infection control purposes in particular. Copyright © 2012, American Society for Microbiology. All Rights Reserved.

Loading Service de Bacteriologie Virologie collaborators
Loading Service de Bacteriologie Virologie collaborators