Unsuitability of MALDI-TOF MS to discriminate Acinetobacter baumannii clones under routine experimental conditions

• Type: Article in International Scientific Journal
• Date: 2015

Authors

Sousa, C (Author) Other; Botelho, J (Author) Other; Grosso, F (Author) Other; Silva, L (Author) Other; Lopes, J (Author) Other; Luisa Peixe (Author) FFUP

Journal

Title: Frontiers in Microbiology

Vol. 6

ISSN: 1664-302X

Publisher: FRONTIERS MEDIA SA

Indexing

ISI Web of Knowledge - 16 Citations

Scopus - 22 Citations

Other information

Authenticus ID: P-00G-BS8

DOI: 10.3389/fmicb.2015.00481

Abstract (EN): MALDI-TOF MS (matrix-assisted laser desorption/ionization time-of-flight mass spectrometry) is now in the forefront for routine bacterial species identification methodologies, being its value for clonality assessment controversial. In this work we evaluated the potential of MALDI-TOF MS for assisting infection control by depicting Acinetobacter baumannii clones. Mass spectra of 58 A. baumannii clinical isolates belonging to the worldwide spread lineages (ST98, ST103, ST208, and ST218) isolated in our country, were obtained and analyzed with several chemometric tools (pseudo gel views, peakfind function, and partial least squares discriminant analysis). The clonal lineages were obtained using the "Oxford" scheme, belonging ST98, ST208, and ST218 to the international clone II and ST103 to an epidemic clonal lineage (SG5). Additionally, mass spectra of a highly diverse international collection of 38 isolates belonging to 22 sequence types (STs) were obtained for further comparisons. Pseudo gel views and direct peak pattern analysis did not allow the discrimination of A. baumannii isolates belonging to 5T98, ST103, 5T208, or ST21 8. Moreover, a partial least square discriminant analysis of the mass spectra considering two spectral ranges (2-20 kDa and 4-10 kDa) revealed a poor degree of discrimination with only 64.6 and 65.8% of correct ST assignments, respectively. Also, mass spectra of the international isolates (n = 38, 22STs) revealed a very congruent peak pattern among them as well as among the four lineages included in this work. Despite the increasing interest of MALDI-TOF MS for bacterial typing at different taxonomical levels, we demonstrated, using routine experimental conditions, the unsuitability of this methodology for A. baumannii clonal discrimination.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9