Study on carbapenemase-producing bacteria by matrix-assisted laser desorption/ionization approach

Michał Złoch,Paweł Pomastowski,Katrin Sparbier,Bogusław Buszewski,Markus Kostrzewa,Markus Peer,Adriana Calderaro

doi:10.1371/journal.pone.0247369

Michał Złoch, Paweł Pomastowski + Show 5 more

Open Access

https://doi.org/10.1371/journal.pone.0247369

Copy DOI

Abstract

The development of new techniques for the detection of carbapenemase activity is of great importance since the increased incident of resistance against carbapenems represents a serious threat to global public health. In this context, the matrix-assisted laser desorption/ionization approach already demonstrated to be a reliable tool for rapid carbapenemase detection. As a newly developed test, there is still a lack of in-depth analysis of its robustness and possible wider application. The main goal of this study was to evaluate the potential for using the design MBT STAR-Carba assay as the pre-characterization method for Enterobacterales and P. aeruginosa strains in terms of the produced classes of carbapenemases using modified procedure parameters—various suspension densities and incubation times. Moreover, its usefulness for the in-depth analysis and characterization of metallo-β-lactamases (MBL) was tested by applying inhibition assays. In this study, the designed assay proved to be a sensitive tool for the detection of carbapenemase hydrolytic activity, which can be successfully used to partially classify the class of carbapenemase present. Additionally, the use of defined high concentration suspensions would allow to shorten the incubation time to 1 minute for certain strains. Considering that the assay was also suitable to investigate the effect of different inhibitors on the MBL activity, it demonstrates far higher discriminatory potential than only a rapid routine carbapenemase detection tool and could be used as a susceptibility assay.

Highlights

The increasing prevalence of drug-resistant bacteria is a serious threat to human health and life around the world
The principle of designed approach relies on the mass spectrometric evaluation of the carbapenem molecule after a short co-incubation with the bacterial strains, monitoring the distinct mass peaks of the hydrolyzed and non-hydrolyzed forms of the antibiotic resulting from carbapenemase-dependent β-lactam ring degradation [24,25]
Within the first group logRQ values ranged from 0.43–0.87 obtaining the lowest values for GES carbapenemase-producing P. aeruginosa 1 strain

Summary

Introduction

The increasing prevalence of drug-resistant bacteria is a serious threat to human health and life around the world. Carbapenems are amongst the latest developed β-lactam antibiotics still possessing a broad spectrum of bactericidal activity, often used as last resort medication for the treatment of severe bacterial infections [1,2,3]. The global rise of carbapenemase-producing bacteria (CPB) incidence represents an increasing threat to the healthcare system and patient safety and is of great concern worldwide [4,5]. Funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Objectives

Results

Discussion

Conclusion