Applicability of an in-house saponin-based extraction method in Bruker Biotyper matrix-assisted laser desorption/ionization time-of-flight mass spectrometry system for identifying bacterial and fungal species in positively flagged pediatric VersaTREK bloo

Early identification of pathogens causing bloodstream infection (BSI) is critical for prompt administration of appropriate antimicrobial therapy. We used an in-house saponin-based extraction method to evaluate the performance of Bruker Biotyper MALDI-TOF MS system (MALDI Biotyper) for bacterial and fungal identification in 2013 positively-flagged VersaTREK blood culture bottles. A total of 180 monomicrobial and 23 polymicrobial positive blood cultures were investigated. Among monomicrobial positive blood cultures, the MALDI Biotyper recognized 90.6% and 81.7% of organisms directly from the flagged blood culture bottles to the genus and species levels, respectively. The MALDI Biotyper also correctly characterized one of the polymicrobial organisms to the species level in 20 (87%) bottles and to the genus level in 21 (91.3%) bottles. The overall identification rate using our protocol was 90.6% (184/203) and 82.3% (167/203) for genus and species levels, respectively. Identification accuracy was higher for Gram-positive than Gram-negative organisms and was the lowest for yeasts. Score values of identification were ≥1.500 for 200 (98.5%) bottles, ≥1.700 for 195 (96.1%) bottles and ≥2.000 for 182 (89.7%) bottles. Moreover, 83.5% and 92% of the isolates were identified precisely to species and genus level with the lower cutoff score of 1.500. Using our protocol also helped identifying BSI pathogens 18-24 h earlier compared to the sub-cultured colonies. Using Bruker MALDI Biotyper for identification of isolates directly from positive VersaTREK blood culture bottles, our in-house saponin-based protocol provided a more rapid turn-around time for correct identification of BSI pathogens than the conventional methods.

Hu YL ，Hsueh SC ，Ding GS ，Chuang PC ，Chen JM ，Lu CY ，Chang LY ，Huang LM ，Lee PI ，Hsueh PR ... -  《-》

Applicability of an in-House Saponin-Based Extraction Method in Bruker Biotyper Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry System for Identification of Bacterial and Fungal Species in Positively Flagged Blood Cultures.

Chien JY ，Lee TF ，Du SH ，Teng SH ，Liao CH ，Sheng WH ，Teng LJ ，Hsueh PR ... -  《Frontiers in Microbiology》

Rapid identification of bloodstream bacterial and fungal pathogens and their antibiotic resistance determinants from positively flagged blood cultures using the BioFire FilmArray blood culture identification panel.

Rapid and accurate identification of pathogens and their antibiotic resistance directly from flagged blood cultures can aid clinicians in optimizing early antibiotic treatment and improve the clinical outcomes, especially in settings associated with high rates of bloodstream infection caused by vancomycin-resistant Enterococci (VRE) and carbapenem-resistant Enterobacteriaceae (CRE). We compared the results of the BioFire FilmArray Blood Culture Identification (BCID) panel with those of conventional methods for identifying the pathogens and their antibiotic susceptibility status. In total, 100 randomly selected positive blood cultures (BACTEC Plus Aerobic/F bottles or BACTEC Anaerobic Lytic/10 bottles) were analyzed. The pathogen detection efficiency of FilmArray BCID panel was compared with that of conventional method using MALDI-TOF MS system (Bruker MALDI Biotyper) and susceptibility testing by the Vitek 2 system. The sequencing analysis of antibiotic resistance genes was performed for discrepant results obtained from MALDI Biotyper and Vitek 2. Among the 100 positively flagged blood cultures, 94% of FilmArray BCID panel results were consistent with the MALDI Biotyper results. All five VRE isolates positive for vanA/vanB genes, 10 of 12 Staphylococcus species positive for mecA gene, and only one Klebsiella pneumoniae isolate positive for K. pneumoniae carbapenemase gene (blaKPC) detected in the FilmArray BCID panel were also concordant with results by the results by conventional susceptibility testing/molecular confirmation. The FilmArray BCID panel results not only demonstrated good correlation with conventional blood culture identification and susceptibility results but also provided results rapidly, especially for the early detection of MRSA, VRE and blaKPC-mediated CRE.

Kang CM ，Chen XJ ，Chih CC ，Hsu CC ，Chen PH ，Lee TF ，Teng LJ ，Hsueh PR ... -  《-》

Evaluation of Rapid Sepsityper® protocol and specific MBT-Sepsityper module (Bruker Daltonics) for the rapid diagnosis of bacteremia and fungemia by MALDI-TOF-MS.

Ponderand L ，Pavese P ，Maubon D ，Giraudon E ，Girard T ，Landelle C ，Maurin M ，Caspar Y ... -  《Annals of Clinical Microbiology and Antimicrobials》

Identification of blood culture isolates directly from positive blood cultures by use of matrix-assisted laser desorption ionization-time of flight mass spectrometry and a commercial extraction system: analysis of performance, cost, and turnaround time.

Lagacé-Wiens PR ，Adam HJ ，Karlowsky JA ，Nichol KA ，Pang PF ，Guenther J ，Webb AA ，Miller C ，Alfa MJ ... -  《-》