title: Rapid detection of carbapenemase-producing Klebsiella pneumoniae strains derived from blood cultures by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS).
abstract: Carbapenemase-producing Enterobacteriaceae (CPE), particularly carbapenemase-producing Klebsiella pneumoniae isolates, are important causative agents of nosocomial infections associated with significant mortality rates mostly in critical wards. The rapid detection and typing of these strains is critical either for surveillance purposes and to prevent outbreaks and optimize antibiotic therapy. In this study, the MALDI-TOF MS method was used to detect rapidly these isolates from blood cultures (BCs) and to obtain proteomic profiles enable to discriminate between carbapenemase-producing and non-carbapenemase-producing strains.
  
  
  
  Fifty-five K. pneumoniae strains were tested. Identification and carbapenemase-production detection assay using Ertapenem were performed both from bacterial pellets extracted directly from BCs flasks and from subcultures of these strains. For all isolates, a complete antimicrobial susceptibility testing and a genotypic characterization were performed. We found 100% agreement between the carbapenemase-producing profile generated by MALDI TOF MS and that obtained using conventional methods. The assay detected and discriminated different carbapenemase-producing K. pneumoniae isolates within 30 min to 3 h after incubation with Ertapenem.
  
  
  
  MALDI-TOF MS is a promising, rapid and economical method for the detection of carbapenemase-producing K. pneumoniae strains that could be successfully introduced into the routine diagnostic workflow of clinical microbiology laboratories.
authors.affiliation: Department of Experimental Medicine and Surgery, "Tor Vergata" University of Rome, Via Montpellier 1, 00133, Rome, Italy. cristina_sakarikou@yahoo.it.
authors.forename: Christina
authors.initials: C
authors.lastname: Sakarikou
authors.affiliation: Laboratory of Clinical Microbiology and Virology, Polyclinic "Tor Vergata" Foundation, V.le Oxford 81, 00133, Rome, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Ciotti
authors.affiliation: Department of Experimental Medicine and Surgery, "Tor Vergata" University of Rome, Via Montpellier 1, 00133, Rome, Italy.
authors.forename: Camilla
authors.initials: C
authors.lastname: Dolfa
authors.affiliation: Clinical Pathology and Microbiology Laboratory, University Hospital Campus Bio-Medico, Via Alvaro del Portillo 200, 00128, Rome, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Angeletti
authors.affiliation: Department of Experimental Medicine and Surgery, "Tor Vergata" University of Rome, Via Montpellier 1, 00133, Rome, Italy.|Laboratory of Clinical Microbiology and Virology, Polyclinic "Tor Vergata" Foundation, V.le Oxford 81, 00133, Rome, Italy.
authors.forename: Cartesio
authors.initials: C
authors.lastname: Favalli
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis / Q000302:isolation & purification*; D015373:Bacterial Typing Techniques / Q000379:methods*; D000071997:Blood Culture / Q000379:methods*; D018929:Cell Culture Techniques; D003428:Cross Infection; D004755:Enterobacteriaceae / Q000201:enzymology / Q000302:isolation & purification; D000077727:Ertapenem; D006801:Humans; D007558:Italy; D007710:Klebsiella Infections / Q000175:diagnosis; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000201:enzymology* / Q000302:isolation & purification; D007753:Laboratories; D040901:Proteomics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000191:economics / Q000379:methods*; D013997:Time Factors; D001618:beta-Lactamases / Q000032:analysis / Q000302:isolation & purification*; D047090:beta-Lactams / Q000494:pharmacology
chemical_list: D001426:Bacterial Proteins; D047090:beta-Lactams; D001618:beta-Lactamases; C063912:carbapenemase; D000077727:Ertapenem
keywords: Blood culture; Carbapenemases; Detection; Klebsiella pneumoniae; MALDI-TOF MS