Related Experiment Video
Updated: Dec 12, 2025
Subtyping of Campylobacter jejuni ssp. doylei Isolates Using Mass Spectrometry-based PhyloProteomics MSPP
Published on: October 30, 2016
Detection of beta-lactamase production in clinical Prevotella species by MALDI-TOF MS method
Nurver Ulger Toprak1, Oncu Akgul1, József Sóki2
1Marmara University School of Medicine, Department of Microbiology, Istanbul, Turkey.
Abstract:
Penicillins, can be used in treatment of infections due to Prevotella species if they are susceptible to penicillin. Early and accurate preliminary detection of β-lactamase-producing isolates is crucial for treatment of infection. The aim of this study was to determine β-lactamase-producing Prevotella species by MALDI-TOF MS and screen them for the presence of cfxA gene, responsible for β-lactamase production. A total of 500 clinically relevant Prevotella isolates, collected from 13 countries for the previous European antibiotic resistance surveillance study, were tested. Susceptibility testing was performed against ampicillin and ampicillin/sulbactam by Etest methodology. EUCAST guidelines were used for susceptibility interpretations; the isolates with MIC value ≤ 0.5 for ampicillin were considered susceptible and >2 resistant. All Prevotella isolates, were tested for detection of β-lactamase activity by MALDI-TOF MS (Vitek® MS Research Use Only) system and the presence of the cfxA gene by PCR method. The susceptibility levels of the isolates to ampicillin/sulbactam and ampicillin were 99.6% and 43.4%, respectively. A total 59% of isolates presented β-lactamase activity and 60.8% were cfxA gene positive. Both these tests were positive for isolates in the resistant category. Additionally, >95% of the isolates (n = 65) which ampicillin MIC values ranged from >0.5 μg/mL to 2 μg/ml displayed β-lactamase activity. We also found that the MALDI-TOF MS-based β-lactamase assay delivers results in 2 h. We found a high concordance between the MALDI-TOF MS β-lactamase results in terms of cfxA β-lactamase gene presence. MALDI-TOF MS may serve as a simple and efficient alternative method of the existing phenotypic and PCR-based methods.
Insights
Detecting beta-lactamase producing Prevotella is crucial for effective penicillin treatment. MALDI-TOF MS offers a rapid and accurate method for identifying these resistant bacteria and their resistance genes.
Area of Science:
- Microbiology
- Clinical Diagnostics
- Antimicrobial Resistance
Background:
- Penicillins are vital for treating Prevotella infections, but resistance mediated by beta-lactamase enzymes can limit efficacy.
- Early detection of beta-lactamase-producing Prevotella is critical for guiding appropriate antibiotic selection and improving patient outcomes.
Purpose of the Study:
- To evaluate Matrix-Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) for rapid detection of beta-lactamase activity in Prevotella species.
- To screen Prevotella isolates for the presence of the cfxA gene, a key determinant of beta-lactamase production, and correlate findings with MALDI-TOF MS results.
Main Methods:
- A total of 500 Prevotella isolates were tested for susceptibility to ampicillin and ampicillin/sulbactam using Etest.
- Beta-lactamase activity was detected using MALDI-TOF MS (Vitek® MS Research Use Only), and the cfxA gene was identified by PCR.
- Isolates with ampicillin Minimum Inhibitory Concentration (MIC) ≤0.5 μg/mL were considered susceptible, and >2 μg/mL as resistant, following EUCAST guidelines.
Main Results:
- High susceptibility rates to ampicillin/sulbactam (99.6%) and lower rates to ampicillin (43.4%) were observed.
- 59% of isolates exhibited beta-lactamase activity, and 60.8% were positive for the cfxA gene, with both tests correlating with ampicillin resistance.
- MALDI-TOF MS provided beta-lactamase detection results within 2 hours, showing high concordance with cfxA gene presence and phenotypic resistance.
Conclusions:
- MALDI-TOF MS is a rapid, efficient, and reliable method for detecting beta-lactamase activity in Prevotella species.
- This technique can aid in the timely identification of resistant isolates, facilitating appropriate treatment decisions for Prevotella infections.
- MALDI-TOF MS offers a valuable alternative to traditional phenotypic and PCR-based methods for beta-lactamase detection in clinical microbiology laboratories.
Related Concept Videos
01:19MALDI-TOF Mass Spectrometry
01:33Peptide Identification Using Tandem Mass Spectrometry
This technique helps gather information regarding the protein from which the peptide was obtained and to study the peptides’ amino acid sequence. Identifying peptides from a complex mixture is an important component of the growing field of...