Discrimination of multilocus sequence typing-based Campylobacter jejunisubgroups by MALDI-TOF mass spectrometry

BMC Microbiology

Research Article

Abdul Malik Tareen¹  Uwe Groß¹  Michael Weig¹  Raimond Lugert¹  Oliver Bader¹  Andreas Erich Zautner²  Wycliffe Omurwa Masanta² 

[1] UMG-Labor/Institut für Medizinische Mikrobiologie, Universitätsmedizin Göttingen, Kreuzbergring 57, 37075Göttingen, Germany;UMG-Labor/Institut für Medizinische Mikrobiologie, Universitätsmedizin Göttingen, Kreuzbergring 57, 37075Göttingen, Germany;UMG-Labor/Institut für Klinische Chemie - Zentrallabor, Universitätsmedizin Göttingen, Robert-Koch-Straße 40, 37075Göttingen, Germany;

关键词: MALDI-TOF species identification;    Phyloproteomics;    Multilocus sequence typing;    MLST;    Intact cell mass spectrometry;    ICMS;    Principal component analysis;    PCA;    Campylobacter jejuni;   

DOI  :  10.1186/1471-2180-13-247

 received in 2013-07-17, accepted in 2013-10-30,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundCampylobacter jejuni, the most common bacterial pathogen causing gastroenteritis, shows a wide genetic diversity. Previously, we demonstrated by the combination of multi locus sequence typing (MLST)-based UPGMA-clustering and analysis of 16 genetic markers that twelve different C. jejuni subgroups can be distinguished. Among these are two prominent subgroups. The first subgroup contains the majority of hyperinvasive strains and is characterized by a dimeric form of the chemotaxis-receptor Tlp7m+c. The second has an extended amino acid metabolism and is characterized by the presence of a periplasmic asparaginase (ansB) and gamma-glutamyl-transpeptidase (ggt).ResultsPhyloproteomic principal component analysis (PCA) hierarchical clustering of MALDI-TOF based intact cell mass spectrometry (ICMS) spectra was able to group particular C. jejuni subgroups of phylogenetic related isolates in distinct clusters. Especially the aforementioned Tlp7m+c+ and ansB+/ ggt+ subgroups could be discriminated by PCA. Overlay of ICMS spectra of all isolates led to the identification of characteristic biomarker ions for these specific C. jejuni subgroups. Thus, mass peak shifts can be used to identify the C. jejuni subgroup with an extended amino acid metabolism.ConclusionsAlthough the PCA hierarchical clustering of ICMS-spectra groups the tested isolates into a different order as compared to MLST-based UPGMA-clustering, the isolates of the indicator-groups form predominantly coherent clusters. These clusters reflect phenotypic aspects better than phylogenetic clustering, indicating that the genes corresponding to the biomarker ions are phylogenetically coupled to the tested marker genes. Thus, PCA clustering could be an additional tool for analyzing the relatedness of bacterial isolates.

【 授权许可】

CC BY   
© Zautner et al.; licensee BioMed Central Ltd. 2013