Journal: Emerging Infectious Diseases
Article Title: Capsule Typing of Haemophilus influenzae by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry 1
Figure Lengend Snippet: Culture collections and methods used in this study for capsule typing of Haemophilus influenzae by MALDI-TOF mass spectrometry. An evaluation set of H. influenzae isolates of all capsule types from diverse geographic origins and time periods and isogenic capsule transformants ( 30 ) were used to investigate capsule type-specific differences in MALDI-TOF mass spectra. MLST was used to ensure adequate coverage of different genetic lineages of encapsulated H. influenzae . Reference isolates from the evaluation set (encapsulated and nonencapsulated) were selected to construct a new typing database in MALDI Biotyper. This database was tested with the remaining isolates in the set, and misclassified isolates were added to the database. The final supplemented database was blindly validated with a second culture collection that consisted of clinical invasive isolates. Hia, H. influenzae type a; Hib, H. influenzae type b; Hic, H. influenzae type c; Hid, H. influenzae type d; Hie, H. influenzae type e; Hif, H. influenzae type f; MALDI-TOF, matrix-assisted laser desorption/ionization time-of-flight; MLST, multilocus sequence typing; NTHi, nontypeable H. influenzae.
Article Snippet: Construction and Validation of a MALDI Biotyper Database for Capsule Typing We used selected isolates from the evaluation set to create main spectra (MSPs) for a new MALDI Biotyper 4.1 database (Bruker Daltonics) ( ).
Techniques: Mass Spectrometry, Construct, Hydrophobic Interaction Chromatography, Sequencing