Optimization of the MALDIxin test for the rapid identification of colistin resistance in Klebsiella pneumoniae using MALDI-TOF MS.
J Antimicrob Chemother
; 75(1): 110-116, 2020 01 01.
Article
em En
| MEDLINE
| ID: mdl-31580426
ABSTRACT
BACKGROUND:
With the dissemination of carbapenemase producers, a revival of colistin was observed for the treatment of infections caused by MDR Gram-negatives. Unfortunately, the increasing usage of colistin led to the emergence of resistance. In Klebsiella pneumoniae, colistin resistance arises through addition of 4-amino-l-arabinose (l-Ara4N) or phosphoethanolamine (pEtN) to the native lipid A. The underlying mechanisms involve numerous chromosome-encoded genes or the plasmid-encoded pEtN transferase MCR. Currently, detection of colistin resistance is time-consuming since it still relies on MIC determination by broth microdilution. Recently, a rapid diagnostic test based on MALDI-TOF MS detection of modified lipid A was developed (the MALDIxin test) and tested on Escherichia coli and Acinetobacter baumannii.OBJECTIVES:
Optimize the MALDIxin test for the rapid detection of colistin resistance in K. pneumoniae.METHODS:
This optimization consists of an additional mild-acid hydrolysis of 15 min in 1% acetic acid. The optimized method was tested on a collection of 81 clinical K. pneumoniae isolates, including 49 colistin-resistant isolates (45 with chromosome-encoded resistance, 3 with MCR-related resistance and 1 with both mechanisms).RESULTS:
The optimized method allowed the rapid (<30 min) identification of l-Ara4N- and pEtN-modified lipid A of K. pneumoniae, which are known to be the real triggers of polymyxin resistance. At the same time, it discriminates between chromosome-encoded and MCR-related polymyxin resistance.CONCLUSIONS:
The MALDIxin test has the potential to become an accurate tool for the rapid determination of colistin resistance in clinically relevant Gram-negative bacteria.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Colistina
/
Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
/
Farmacorresistência Bacteriana
/
Klebsiella pneumoniae
/
Lipídeo A
/
Antibacterianos
Tipo de estudo:
Diagnostic_studies
Limite:
Humans
Idioma:
En
Revista:
J Antimicrob Chemother
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Reino Unido