title: Revisited distribution of nonfermenting Gram-negative bacilli clinical isolates.
abstract: Nonfermenting Gram-negative bacilli (NF-GNB) are ubiquitous environmental opportunistic bacteria frequently misidentified by conventional phenotypic methods. The aim of this study was to determine the distribution of NF-GNB species by 16 S rRNA gene sequencing (used as reference method) and to compare performances of biochemical tests and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). From nine French hospitals, 188 NF-GNB isolates (except P. aeruginosa and A. baumannii) were prospectively collected from 187 clinical samples between December 2008 and May 2009. By using the genotypic approach, 173 (92%) and 188 (100%) isolates were identified to the species and genus level, respectively. They covered 35 species and 20 genera, with a predominance of Stenotrophomonas maltophilia, Achromobacter xylosoxidans, and Pseudomonas putida group bacteria. Of the 173 species-level identified strains, concordant identification to the species-level was obtained for 75.1%, 83% and 88.9% of isolates with API 20 NE strip, the VITEK-2 (ID-GN card) system and MALDI-TOF-MS, respectively. By excluding S. maltophilia isolates accurately identified by the three methods, genus-level identification was much higher for MALDI-TOF-MS (92.9%), compared with API 20 NE and VITEK-2 (76.2% and 80.8%, respectively). In conclusion, MALDI-TOF-MS represents a rapid, inexpensive, and accurate tool for routine identification of NF-GNB in human clinical samples.
authors.affiliation: Service de Bactériologie-Virologie, Groupe Hospitalier Lariboisière-Fernand Widal, Assistance Publique-Hôpitaux de Paris, 2 rue Ambroise Paré, 75475 Paris Cedex 10, France. herve.jacquier@lrb.aphp.fr
authors.forename: H
authors.initials: H
authors.lastname: Jacquier
authors.forename: E
authors.initials: E
authors.lastname: Carbonnelle
authors.forename: S
authors.initials: S
authors.lastname: Corvec
authors.forename: M
authors.initials: M
authors.lastname: Illiaquer
authors.forename: A
authors.initials: A
authors.lastname: Le Monnier
authors.forename: E
authors.initials: E
authors.lastname: Bille
authors.forename: J R
authors.initials: JR
authors.lastname: Zahar
authors.forename: J L
authors.initials: JL
authors.lastname: Beretti
authors.forename: F
authors.initials: F
authors.lastname: Jauréguy
authors.forename: V
authors.initials: V
authors.lastname: Fihman
authors.forename: J
authors.initials: J
authors.lastname: Tankovic
authors.forename: V
authors.initials: V
authors.lastname: Cattoir
mesh_terms: D015373:Bacterial Typing Techniques / Q000379:methods*; D005602:France; D006090:Gram-Negative Bacteria / Q000145:classification* / Q000302:isolation & purification*; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology*; D006761:Hospitals; D006801:Humans; D017422:Sequence Analysis, DNA; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*