ABSTRACT
Shotgun proteomics using liquid chromatography-tandem mass spectrometry (LC-MS/MS) was applied to detect ß-lactamases in clinical Acinetobacter baumannii isolates. The correlation of the detection of ß-lactamase proteins (rather than PCR detection of the corresponding genes) with the resistance phenotypes demonstrated an added value for LC-MS/MS in antimicrobial susceptibility testing.
Subject(s)
Acinetobacter baumannii/drug effects , Acinetobacter baumannii/enzymology , Carbapenems/pharmacology , Ceftazidime/pharmacology , Drug Resistance, Multiple, Bacterial , beta-Lactamases/analysis , Acinetobacter Infections/microbiology , Acinetobacter baumannii/chemistry , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/analysis , Bacterial Proteins/chemistry , Bacterial Typing Techniques , Chromatography, Liquid , Humans , Microbial Sensitivity Tests , Molecular Sequence Data , Peptide Mapping/methods , Proteomics/methods , Tandem Mass Spectrometry , beta-Lactamases/chemistryABSTRACT
The rapid identification of existing and emerging respiratory viruses is crucial in combating outbreaks and epidemics. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a rapid and reliable identification method in bacterial diagnostics, but has not been used in virological diagnostics. Mass spectrometry systems have been investigated for the identification of respiratory viruses. However, sample preparation methods were laborious and time-consuming. In this study, a reliable and rapid sample preparation method was developed allowing identification of cultured respiratory viruses. Tenfold serial dilutions of ten cultures influenza A strains, mixed samples of influenza A virus with human metapneumovirus or respiratory syncytial virus, and reconstituted clinical samples were treated with the developed sample preparation method. Subsequently, peptides were subjected to MALDI-TOF MS and liquid chromatography tandem mass spectrometry (LC-MS/MS). The influenza A strains were identified to the subtype level within 3h with MALDI-TOF MS and 6h with LC-MS/MS, excluding the culturing time. The sensitivity of LC-MS/MS was higher compared to MALDI-TOF MS. In addition, LC-MS/MS was able to discriminate between two viruses in mixed samples and was able to identify virus from reconstituted clinical samples. The development of an improved and rapid sample preparation method allowed generic and rapid identification of cultured respiratory viruses by mass spectrometry.
