title: Evaluation of a DNA microarray for the rapid detection of extended-spectrum β-lactamases (TEM, SHV and CTX-M), plasmid-mediated cephalosporinases (CMY-2-like, DHA, FOX, ACC-1, ACT/MIR and CMY-1-like/MOX) and carbapenemases (KPC, OXA-48, VIM, IMP and NDM).
abstract: OBJECTIVE
  Carbapenem-resistant Gram-negative bacilli are reported increasingly and represent an emerging public health concern. Laboratory detection of extended-spectrum β-lactamase (ESBL), plasmid-mediated cephalosporinase (pAmpC) and carbapenemase producers remains a challenge for microbiology laboratories and is important to avoid clinical failure due to inappropriate antimicrobial therapy and to prevent nosocomial outbreaks. We evaluated a novel microarray, the 'Check-MDR CT103 array' test (Check-Points, Wageningen, The Netherlands), that employs highly specific DNA markers to identify the β-lactamase genes of ESBLs (TEM, SHV and CTX-M, and discriminates between ESBL and non-ESBL TEM and SHV variants), of pAmpC (CMY-2-like, DHA, FOX, ACC-1, ACT/MIR and CMY-1-like/MOX) and of carbapenemases (KPC, OXA-48, VIM, IMP and NDM).
  
  
  METHODS
  One-hundred-and-eighty-seven well-characterized Gram-negative bacilli isolates possessing different bla genes were tested. Total DNAs were extracted using a Qiagen DNA mini kit. The 'Check-MDR CT103 array' was used as recommended by the manufacturer.
  
  
  RESULTS
  The system correctly identified representatives of the three ESBL gene families tested, including differentiation between non-ESBL and ESBL TEM and SHV variants. All bla(CTX-M) genes were classified into the appropriate family group (i.e. CTX-M-1 group, CTX-M-2 group, CTX-M-9 group and CTX-M-8/25/26 group). In addition, the clinically relevant plasmid-encoded cephalosporinase and carbapenemase genes were also reliably detected. Specificities and sensitivities of 100% were recorded for most bla genes.
  
  
  CONCLUSIONS
  The 'Check-MDR CT103 array' is a powerful high-throughput tool for rapid identification of ESBL, pAmpC and carbapenemase producers in culture. Because of its rapid performance, this platform is a valuable tool for epidemiological or infection control studies.
authors.affiliation: Service de Bactériologie-Virologie, INSERM U914: 'Emerging Resistance to Antibiotics',  Hôpital de Bicêtre, Faculté de Médecine Paris Sud, Assistance Publique-Hôpitaux de Paris, Le Kremlin-Bicêtre,  France.
authors.forename: Gaelle
authors.initials: G
authors.lastname: Cuzon
authors.forename: Thierry
authors.initials: T
authors.lastname: Naas
authors.forename: Pierre
authors.initials: P
authors.lastname: Bogaerts
authors.forename: Youri
authors.initials: Y
authors.lastname: Glupczynski
authors.forename: Patrice
authors.initials: P
authors.lastname: Nordmann
mesh_terms: D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D006090:Gram-Negative Bacteria / Q000201:enzymology* / Q000235:genetics*; D008826:Microbial Sensitivity Tests / Q000379:methods; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D012680:Sensitivity and Specificity; D013997:Time Factors; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D004269:DNA, Bacterial; D001618:beta-Lactamases