Two-site study on performances of a commercially available MALDI-TOF MS-based assay for the detection of colistin resistance in Escherichia coli.

Colistin is a last resort drug for the treatment of multiple drug-resistant (MDR) Gram-negative bacterial infections. Rapid methods to detect resistance are highly desirable. Here, we evaluated the performance of a commercially available MALDI-TOF MS-based assay for colistin resistance testing in Escherichia coli at two different sites.

MALDI-TOF Mass Spectrometry-Based Optochin Susceptibility Testing for Differentiation of from other Group Streptococci.

Discrimination of from other group (SMG) species is still challenging but very important due to their different pathogenic potential. In this study, we aimed to develop a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS)-based optochin susceptibility test with an objective read-out. Optimal test performance was established and evaluated by testing consecutively collected respiratory isolates.

Rapid Simultaneous Testing of Multiple Antibiotics by the MALDI-TOF MS Direct-on-Target Microdroplet Growth Assay.

Accelerating antimicrobial susceptibility testing (AST) is a priority in the development of novel microbiological methods. The MALDI-TOF MS-based direct-on-target microdroplet growth assay (DOT-MGA) has recently been described as a rapid phenotypic AST method. In this proof-of-principle study, we expanded this method to simultaneously test 24 antimicrobials.

Detection of Methicillin Resistance in From Agar Cultures and Directly From Positive Blood Cultures Using MALDI-TOF Mass Spectrometry-Based Direct-on-Target Microdroplet Growth Assay.

Matrix-assisted laser desorption/ionization time-of-flight-mass spectrometry (MALDI-TOF MS)-based direct-on-target microdroplet growth assay (DOT-MGA) was recently described as a novel method of phenotypic antimicrobial susceptibility testing (AST). Here, we developed the application of MALDI-TOF MS-based DOT-MGA for Gram-positive bacteria including AST from agar cultures and directly from positive blood cultures (BCs) using the detection of methicillin resistance as example. Consecutively collected, a total of 14 methicillin-resistant (MRSA) and 14 methicillin-susceptible (MSSA) clinical isolates were included.