MALDI Biotyper Systems RUO

MBT STAR-BL Software Module

Selective testing of ß-lactamase activity using MALDI-TOF mass spectrometry

The threat of multi-resistant bacteria

Antibiotics are important therapeutics for the treatment of patients with bacterial infections. However, the misuse of antibiotics leads to the emergence and selection of resistant bacteria. Doctors now sometimes face situations where infected patients cannot be treated adequately because the responsible bacterium is resistant to available antibiotics. 

Carbapenem resistance

Of the different resistance mechanisms used by bacteria, an important mechanism is the enzymatic inactivation of antibiotics by extended-spectrum beta-lactamases (ESBLs) and carbapenemases. Bacteria which have acquired this resistance mechanism are resistant to carbapenem antibiotics and are a major threat to the health-care system. Carbapenems are members of the beta-lactam class of antibiotics. Because of their basic structure, carbapenems have a high resistance to destructive bacteria enzymes and are therefore “last resort” antibiotics to treat life-threatening infections caused by multi-resistant bacteria in situations where traditional antibiotics are ineffective. 

Fast and cost-efficient methods are therefore required to facilitate rapid resistance evaluation for hygienic and therapeutic measures.

Selective testing of antibiotic resistance using MALDI-TOF mass spectrometry

To aid the fight against resistant bacteria, Bruker has developed the MBT Compass STAR-BL software module. This software expands the capabilities of the MBT Star-BL beyond the identification of microorganisms by enabling fast and accurate analysis of the level of beta-lactamase activity in bacterial cultures in microbiological research.

To analyze beta-lactamase activity, bacteria samples are co-incubated with a beta-lactam antibiotic. Bacteria resistant to this antibiotic will be able to hydrolyze the antibiotic. This hydrolyzation is coupled with a mass shift of the molecule which can be measured using mass spectrometry.

Selective testing of antibiotic resistance using MALDI-TOF mass spectrometry
Hydrolyses of the beta-lactam ring of beta-lactam antibiotics (click to enlarge)

After incubation, cell-free supernatant is spotted onto a MALDI target plate and spectra of the antibiotic are acquired. After spectra acquisition, the MBT STAR-BL software module automatically calculates the summed hydrolyzed and non-hydrolyzed (intact) antibiotic signal intensities and the corresponding ratio. Results are displayed as a plot that enables at-a-glance evaluation. 

To download the brochure click here.

MBT STAR BL Software Screen
(click to enlarge)

Not for use in clinical diagnostic procedures.