"CORE" a new assay for rapid identification of Klebsiella pneumoniae COlistin REsistant strains by MALDI-TOF MS in positive-ion mode

Gianluca Foglietta; Elena De Carolis; Giordana Mattana; Manuela Onori; Marilena Agosta; Claudia Niccolai; Vincenzo Di Pilato; Gian Maria Rossolini; Maurizio Sanguinetti; Carlo Federico Perno; Paola Bernaschi

doi:10.3389/fmicb.2023.1045289

"CORE" a new assay for rapid identification of Klebsiella pneumoniae COlistin REsistant strains by MALDI-TOF MS in positive-ion mode

Front Microbiol. 2023 Feb 22:14:1045289. doi: 10.3389/fmicb.2023.1045289. eCollection 2023.

Affiliations

¹ Microbiology Unit and Diagnostic Immunology, Bambino Gesù Pediatric Hospital, IRCCS, Rome, Italy.
² Microbiology Unit, Department of Laboratory Sciences and Infectious Diseases, Fondazione Policlinico Universitario A. Gemelli, IRCCS, Rome, Italy.
³ Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy.
⁴ Department of Surgical Sciences and Integrated Diagnostics (DISC), University of Genoa, Genoa, Italy.
⁵ Clinical Microbiology and Virology Unit, University Hospital Careggi, Florence, Italy.

Abstract

Due to the global spread of pan resistant organisms, colistin is actually considered as one of the last resort antibiotics against MDR and XDR bacterial infections. The emergence of colistin resistant strains has been observed worldwide in Gram-negative bacteria, such as Enterobacteriaceae and especially in K. pneumoniae, in association with increased morbidity and mortality. This landscape implies the exploration of novel assays able to target colistin resistant strains rapidly. In this study, we developed and evaluated a new MALDI-TOF MS assay in positive-ion mode that allows quantitative or qualitative discrimination between colistin susceptible (18) or resistant (32) K. pneumoniae strains in 3 h by using the "Autof MS 1000" mass spectrometer. The proposed assay, if integrated in the diagnostic workflow, may be of help for the antimicrobial stewardship and the control of the spread of K. pneumoniae colistin resistant isolates in hospital settings.

Keywords: Klebsiella pneumoniae; MALDI-TOF MS; colistin resistance detection; positive-ion mode; rapid assay.