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Characterization of S taphylococcus aureus strains isolated from I talian dairy products by MALDI ‐ TOF mass fingerprinting
Author(s) -
Böhme Karola,
Morandi Stefano,
Cremonesi Paola,
Fernández No Inmaculada C.,
BarrosVelázquez Jorge,
Castiglioni Bianca,
Brasca Milena,
Cañas Benito,
CaloMata Pilar
Publication year - 2012
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.201100480
Subject(s) - staphylococcus aureus , mastitis , microbiology and biotechnology , toxin , typing , biology , mass spectrometry , food science , chromatography , chemistry , bacteria , genetics
S taphylococcus aureus is a known pathogen, causing serious food‐borne intoxications due to the production of enterotoxins, being otherwise a major cause of mastitis. In this sense, the detection of S . aureus is an important issue for the food industry to avoid health hazards and economic losses. The present work applied MALDI ‐ TOF MS for the classification of 40 S. aureus strains, 36 isolated from Italian dairy products and four from human samples. All isolated strains were clearly identified as S . aureus by their spectral fingerprints. The peak masses m / z 3444, 5031, and 6887 were determined to be specific biomarkers for S . aureus . Furthermore, clustering of the peak mass lists was successfully applied as a typing method, resulting in eight groups of strains. This is the first time that a detailed spectral comparison was carried out and characteristic peak masses were determined for every spectral group. Three strains exhibited a peak at m / z 6917 instead of m / z 6887, which was related to four polymorphisms in their 16S r RNA sequences. However, the grouping obtained by MALDI ‐ TOF MS fingerprinting could not be related to toxin production or to the origin of the strains.