Abdullah Kilic1,2, Eyup Dogan3, Sinem Kaya3, Sema Oren4, Duran Tok5, Nurittin Ardic3, Mehmet Baysallar3. 1. Department of Microbiology, Gulhane Military Medical Academy, Etlik, 06010, Ankara, Turkey. abkilic@gata.edu.tr. 2. FMF Arthritis Vasculitis and Orphan Disease Research Center (FAVOR), Gulhane Military Medical Academy, Etlik, 06010, Ankara, Turkey. abkilic@gata.edu.tr. 3. Department of Microbiology, Gulhane Military Medical Academy, Etlik, 06010, Ankara, Turkey. 4. FMF Arthritis Vasculitis and Orphan Disease Research Center (FAVOR), Gulhane Military Medical Academy, Etlik, 06010, Ankara, Turkey. 5. Department of Infectious Diseases, Gulhane Military Medical Academy, Etlik, 06010, Ankara, Turkey.
Abstract
BACKGROUND: The aim of this study was to develop a rapid detection method of carbapenem-resistant Klebsiella pneumoniae (CRKP) strains both MALDI-TOF MS and flow cytometry (FCM). METHODS: A total of 174 K. pneumoniae strains were included in this study. Molecular characterization of carbapenemase gene was performed by PCR. Bacterial identification was performed by MALDI-TOF-MS. Meropenem susceptibility was tested at the concentrations of breakpoints described by the Clinical and Laboratory Standards Institute (CLSI) guide by FCM. RESULTS: Sixty-two CRKP were positive for at least one carbapenemase gene. A total of 174 K. pneumoniae isolates obtained from clinically relevant material were correctly identified by Bruker MALDI-TOF MS with log (score) >2.0. These results were 100% concordant with the Phoenix™ Automated Microbiology System (BD, MD) and conventional identification results. Based on the analysis of the receiver operating characteristic (ROC) curves, the best validity and sensitivity data were obtained with a cut-off value of 18.88% by FCM. The concordance, sensitivity, and specificity for FCM by the selected cut-off values were 99.4%, 98.9%, and 100%, respectively. CONCLUSIONS: We conclude that reliable results on bacterial identification and meropenem susceptibility test can be obtained within 2 hr combined by MALDI-TOF-MS and FCM.
BACKGROUND: The aim of this study was to develop a rapid detection method of carbapenem-resistant Klebsiella pneumoniae (CRKP) strains both MALDI-TOF MS and flow cytometry (FCM). METHODS: A total of 174 K. pneumoniae strains were included in this study. Molecular characterization of carbapenemase gene was performed by PCR. Bacterial identification was performed by MALDI-TOF-MS. Meropenem susceptibility was tested at the concentrations of breakpoints described by the Clinical and Laboratory Standards Institute (CLSI) guide by FCM. RESULTS: Sixty-two CRKP were positive for at least one carbapenemase gene. A total of 174 K. pneumoniae isolates obtained from clinically relevant material were correctly identified by Bruker MALDI-TOF MS with log (score) >2.0. These results were 100% concordant with the Phoenix™ Automated Microbiology System (BD, MD) and conventional identification results. Based on the analysis of the receiver operating characteristic (ROC) curves, the best validity and sensitivity data were obtained with a cut-off value of 18.88% by FCM. The concordance, sensitivity, and specificity for FCM by the selected cut-off values were 99.4%, 98.9%, and 100%, respectively. CONCLUSIONS: We conclude that reliable results on bacterial identification and meropenem susceptibility test can be obtained within 2 hr combined by MALDI-TOF-MS and FCM.
Authors: Liang Chen; José R Mediavilla; Andrea Endimiani; Marnie E Rosenthal; Yanan Zhao; Robert A Bonomo; Barry N Kreiswirth Journal: J Clin Microbiol Date: 2010-12-01 Impact factor: 5.948