title: Matrix-assisted laser desorption ionization-time of flight mass spectrometry meropenem hydrolysis assay with NH4HCO3, a reliable tool for direct detection of carbapenemase activity.
abstract: A comparison of a matrix-assisted laser desorption ionization-time of flight mass spectrometric (MALDI-TOF MS) meropenem hydrolysis assay with the Carba NP test showed that both methods exhibited low sensitivity (approximately 76%), mainly due to the false-negative results obtained with OXA-48-type producers. The addition of NH4HCO3 to the reaction buffer for the MALDI-TOF MS assay dramatically improved its sensitivity (98%). Automatic interpretation of the MALDI-TOF MS assay, using the MBT STAR-BL software, generally agreed with the results obtained after manual analysis. For the Carba NP test, spectrophotometric analysis found six additional carbapenemase producers.
authors.affiliation: Department of Microbiology, Faculty of Medicine and University Hospital in Plzen, Charles University in Prague, Plzen, Czech Republic Biomedical Center, Faculty of Medicine and University Hospital in Plzen, Charles University in Prague, Plzen, Czech Republic c.papagiannitsis@gmail.com.
authors.forename: Costas C
authors.initials: CC
authors.lastname: Papagiannitsis
authors.affiliation: Department of Microbiology, Faculty of Medicine and University Hospital in Plzen, Charles University in Prague, Plzen, Czech Republic.
authors.forename: Vendula
authors.initials: V
authors.lastname: Študentová
authors.affiliation: National Medicines Institute, Warsaw, Poland.
authors.forename: Radoslaw
authors.initials: R
authors.lastname: Izdebski
authors.affiliation: Department of Microbiology, Medical School, University of Thessaly, Biopolis, Larissa, Greece.
authors.forename: Olga
authors.initials: O
authors.lastname: Oikonomou
authors.affiliation: Robert Koch Institute, Nosocomial Pathogens and Antibiotic Resistance, Wernigerode, Germany.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Pfeifer
authors.affiliation: Department of Microbiology, Medical School, University of Thessaly, Biopolis, Larissa, Greece.
authors.forename: Efthimia
authors.initials: E
authors.lastname: Petinaki
authors.affiliation: Department of Microbiology, Faculty of Medicine and University Hospital in Plzen, Charles University in Prague, Plzen, Czech Republic Biomedical Center, Faculty of Medicine and University Hospital in Plzen, Charles University in Prague, Plzen, Czech Republic.
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Hrabák
mesh_terms: D057205:Automation, Laboratory; D001426:Bacterial Proteins / Q000032:analysis*; D001639:Bicarbonates; D002021:Buffers; D001330:Electronic Data Processing; D006801:Humans; D006868:Hydrolysis; D000077731:Meropenem; D012680:Sensitivity and Specificity; D012984:Software; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013845:Thienamycins / Q000378:metabolism*; D001618:beta-Lactamases / Q000032:analysis*
chemical_list: D001426:Bacterial Proteins; D001639:Bicarbonates; D002021:Buffers; D013845:Thienamycins; C027043:ammonium bicarbonate; D001618:beta-Lactamases; C063912:carbapenemase; D000077731:Meropenem