Poor Sensitivity of the MALDI Biotyper<sup>®</sup> MBT Subtyping Module for Detection of <i>Klebsiella pneumoniae</i> Carbapenemase (KPC) in <i>Klebsiella</i> Species
Luz Cuello,
Judith Alvarez Otero,
Kerryl E. Greenwood-Quaintance,
Liang Chen,
Blake Hanson,
Jinnethe Reyes,
Lauren Komarow,
Lizhao Ge,
Zane D. Lancaster,
Garrett G. Gordy,
Audrey N. Schuetz,
Robin Patel
Affiliations
Luz Cuello
Infectious Diseases Research Laboratory, Mayo Clinic, Rochester, MN 55905, USA
Judith Alvarez Otero
Infectious Diseases Research Laboratory, Mayo Clinic, Rochester, MN 55905, USA
Kerryl E. Greenwood-Quaintance
Infectious Diseases Research Laboratory, Mayo Clinic, Rochester, MN 55905, USA
Liang Chen
Hackensack Meridian Health Center for Discovery and Innovation, Nutley, NJ 07110, USA
Blake Hanson
Department of Epidemiology, Human Genetics & Environmental Sciences, School of Public Health, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
Jinnethe Reyes
Molecular Genetics and Antimicrobial Resistance Unit, Universidad El Bosque, Bogotá 110121, Colombia
Lauren Komarow
The Biostatistics Center, The George Washington University, Rockville, MD 20852, USA
Lizhao Ge
The Biostatistics Center, The George Washington University, Rockville, MD 20852, USA
Zane D. Lancaster
Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA
Garrett G. Gordy
Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA
Audrey N. Schuetz
Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA
Robin Patel
Infectious Diseases Research Laboratory, Mayo Clinic, Rochester, MN 55905, USA
Rapid detection of Klebsiella pneumoniae carbapenemase (KPC) in the Klebsiella species is desirable. The MALDI Biotyper® MBT Subtyping Module (Bruker Daltonics) uses an algorithm that detects a peak at ~11,109 m/z corresponding to a protein encoded by the p019 gene to detect KPC simultaneously with organism identification by a matrix-assisted laser desorption ionization–time-of-flight mass spectrometry (MALDI-ToF MS). Here, the subtyping module was evaluated using 795 clinical Klebsiella isolates, with whole genome sequences used to assess for blaKPC and p019. For the isolates identified as KPC positive by sequencing, the overall sensitivity of the MALDI-ToF MS subtyping module was 239/574 (42%) with 100% specificity. For the isolates harboring p019, the subtyping module showed a sensitivity of 97% (239/246) and a specificity of 100%. The subtyping module had poor sensitivity for the detection of blaKPC-positive Klebsiella isolates, albeit exhibiting excellent specificity. The poor sensitivity was a result of p019 being present in only 43% of the blaKPC-positive Klebsiella isolates.
