Phosphopeptides with one and four phosphate groups were characterized by MALDI mass spectrometry. The molecular ion of monophosphopeptide could be detected both as positive and negative ions by MALDI TOF with delayed extraction (DE) and in the reflector mode. The tetraphospho peptide could be detected in linear mode. When MS/MS spectra of the monophospho peptides were obtained in a MALDI TOF TO...

Various biochemical, chemical, and microspectroscopic methods have been developed throughout the years for the screening and identification of mutants with altered cell wall structure. However, these procedures fail to provide the insight into structural aspects of the cell wall polymers. In this paper, we present various methods for rapidly screening Arabidopsis cell wall mutants. The enzymati...

• Here we present an N-terminal derivatization approach, using TMPP-Ac-Osu that improves the HPLC performance for small hydrophilic phosphopeptides. • This approach is compatible with LC/MS and LC/MALDI. • The chromatographic enhancement was evaluated by on-line nanoscale HPLC coupled with Electrospray on a Q-Tof PremierTM. • LC-MALDI/MS/MS analysis was also investigated. Both MS/MS on a Q-Tof ...

AIM The performance of Bruker Biotyper matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) in identifying species of nontuberculous mycobacteria (NTM) in flagged Mycobacteria Growth Indicator Tubes (MGIT)s is unclear. MATERIALS & METHODS A total of 92 sequential MGIT-positive nontuberculous mycobacteria isolates, including Mycobacterium intracellulare, ...

Our team in Europe has developed the routine clinical laboratory identification of microorganisms by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). To evaluate the utility of MALDI-TOF MS in tropical Africa in collaboration with local teams, we installed an apparatus in the Hôpital Principal de Dakar (Senegal), performed routine identification of ...

Flavobacteriosis, in Switzerland caused mainly by Flavobacterium psychrophilum (Flavobaceriaceae), has become an important problem for the Swiss fish farming industry. While records of skin and gill infections have been described since a long time, systemic infections, known as the so-called rainbow trout fry syndrome (RTFS), have been reported for the first time not until 1992. Since then, occ...

The genus Pseudoalteromonas constitutes an ecologically significant group of marine Gammaproteobacteria with potential biotechnological value as producers of bioactive compounds and of enzymes. Understanding their roles in the environment and bioprospecting for novel products depend on efficient ways of identifying environmental isolates. Matrix Assisted Laser Desorption/Ionization-Time of Flig...

To explore the discriminatory power of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for detecting subtle differences in isogenic isolates, we tested isogenic strains of Staphylococcus aureus differing in their expression of resistance to methicillin or teicoplanin. More important changes in MALDI-TOF MS spectra were found with strains differing in ...

Rare nonfermenting Gram-negative bacilli, such as Chryseobacterium indologenes and Elizabethkingia meningoseptica, have clinical importance in nosocomial infections and cystic fibrosis (CF), and their identification is a challenge to microbiology laboratories. Thus, the objective of this study was to verify the performance of phenotypic and mass spectrometry (matrix-assisted desorption ionizati...

A comparison of a matrix-assisted laser desorption ionization-time of flight mass spectrometric (MALDI-TOF MS) meropenem hydrolysis assay with the Carba NP test showed that both methods exhibited low sensitivity (approximately 76%), mainly due to the false-negative results obtained with OXA-48-type producers. The addition of NH4HCO3 to the reaction buffer for the MALDI-TOF MS assay dramatically...