Summation of peaks and L34 ribosomal protein in the presence and absence of antibiotics enables susceptibility testing using MALDI-TOF mass spectrometry in 2 h from Escherichia coli-positive blood cultures
| Autor: | Alicia Inés García Señán, Ana de Luis Reboredo, Jose M. González Buitrago, Sara Hernández Egido, Fernando Sánchez-Juanes, Juan Luis Muñoz Bellido, Ana Belén Gil González |
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| Rok vydání: | 2019 |
| Předmět: |
0301 basic medicine
Microbiology (medical) Ribosomal Proteins Cefotaxime Time Factors medicine.drug_class Formic acid 030106 microbiology Antibiotics Microbial Sensitivity Tests medicine.disease_cause 03 medical and health sciences chemistry.chemical_compound Ribosomal protein Ciprofloxacin Escherichia medicine Escherichia coli Humans Bacteriological Techniques Chromatography biology Chemistry biology.organism_classification MALDI-TOF Mass Spectrometry Anti-Bacterial Agents Blood Culture Spectrometry Mass Matrix-Assisted Laser Desorption-Ionization Software medicine.drug |
| Zdroj: | Enfermedades infecciosas y microbiologia clinica (English ed.). 37:244-250 |
| ISSN: | 2529-993X |
| DOI: | 10.1016/j.eimce.2018.06.008 |
| Popis: | Introduction We have developed a MALDI-TOF-mediated phenotypic method, which determines antibiotic susceptibility (AS) from positive blood cultures (BCs) in 2 h. We developed a software for process automation. We report results on Escherichia coli-positive BCs with cefotaxime (CTX) and ciprofloxacin (CIP). Methods We studied CIP and CTX activity in 18 and 17 real E. coli-positive BCs, and in 56 and 45 spiked BCs, respectively. Positive BCs were incubated for 2 h without any antibiotics, and with 2 mg/l and 4 mg/l of CIP and CTX. The extraction was performed using ethanol/formic acid. Spectra were processed with specifically developed software which compares the peaks’ intensity and the size of specific peaks. Results The set cut-off point was a 3-fold decrease in the summation of all peaks and/or the 5382m/z peak value (ribosomal protein L34). In simulated BCs, the correlation of CIP 2 mg/l and 4 mg/l with Etest® was 94.6% and 98.2%, respectively; for CTX 2 mg/l and 4 mg/l, this correlation was 95.6%. In real BCs, the correlations were 100% for CIP (2 mg/l and 4 mg/l) and 88.2% and 94.1% for CTX 2 mg/l and 4 mg/l, respectively. Resistant isolates were always correctly classified. Conclusion This method provides accurate, fast and inexpensive AS information. The method can be automated, making it easier to implement in a microbiology laboratory routine. |
| Databáze: | OpenAIRE |
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