A new MALDI-TOF approach for the quick sequence type identification of Legionella pneumophila.
J Microbiol Methods
; 188: 106292, 2021 09.
Article
in En
| MEDLINE
| ID: mdl-34303751
ABSTRACT
BACKGROUND:
Recently, MALDI-TOF has emerged as a quick tool for bacterial typing. The aim was to evaluate if MALDI-TOF based typing of Legionella pneumophila can achieve the same discriminatory power as that of the Sequence Based Typing (SBT) method.METHODS:
The Sequence Type (ST) was obtained from the 90 strains included in the training set and an in-house MALDI-TOF library based on the Main Spectra Profile (MSP) was generated for the identification of such ST. Then, our library was validated by three procedures a) creating a dendrogram, b) searching for specific peaks present exclusively in each MSP entry, and c) analysing a validation set composed of 14 strains with known ST. Fully characterized L. pneumophila ATCC 33152, which belongs to ST 36, was used as a control strain.RESULTS:
In the training set, 17 strains belonged to ST 1, 1 to ST 20, 63 to ST 22, 1 to ST 146, 6 to ST 578, and 2 to ST 1086. Specific peaks present in each MSPs spectrum, which are considered type-specific biomarkers, ranged from 2 to 11; more concretely, MSP for ST 1 identification shows 2 specific peaks; MSP for ST 20 identification 9 specific peaks; MSP for ST 22 and ST 36 identification 11 specific peaks; MSP for ST 146 identification 5 specific peaks; and MSP for ST 578 and ST 1086 identification 3 specific peaks. Using the validation set (nine strains belonging to ST 22 and five to ST 1), MALDI-TOF assigned accurately the ST in 30 min per tested strain with a full match.CONCLUSIONS:
The ST of L. pneumophila can be identified and reported in few minutes directly from colonies grown on BCYE agar using MALDI-TOF.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Legionella pneumophila
/
Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
/
Molecular Typing
Type of study:
Diagnostic_studies
Limits:
Humans
Language:
En
Journal:
J Microbiol Methods
Year:
2021
Document type:
Article
Affiliation country:
España