title: Delineation of Stenotrophomonas maltophilia isolates from cystic fibrosis patients by fatty acid methyl ester profiles and matrix-assisted laser desorption/ionization time-of-flight mass spectra using hierarchical cluster analysis and principal component analysis.
abstract: Stenotrophomonas maltophilia is an opportunist multidrug-resistant pathogen that causes a wide range of nosocomial infections. Various cystic fibrosis (CF) centres have reported an increasing prevalence of S. maltophilia colonization/infection among patients with this disease. The purpose of this study was to assess specific fingerprints of S. maltophilia isolates from CF patients (n = 71) by investigating fatty acid methyl esters (FAMEs) through gas chromatography (GC) and highly abundant proteins by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and to compare them with isolates obtained from intensive care unit (ICU) patients (n = 20) and the environment (n = 11). Principal component analysis (PCA) of GC-FAME patterns did not reveal a clustering corresponding to distinct CF, ICU or environmental types. Based on the peak area index, it was observed that S. maltophilia isolates from CF patients produced significantly higher amounts of fatty acids in comparison with ICU patients and the environmental isolates. Hierarchical cluster analysis (HCA) based on the MALDI-TOF MS peak profiles of S. maltophilia revealed the presence of five large clusters, suggesting a high phenotypic diversity. Although HCA of MALDI-TOF mass spectra did not result in distinct clusters predominantly composed of CF isolates, PCA revealed the presence of a distinct cluster composed of S. maltophilia isolates from CF patients. Our data suggest that S. maltophilia colonizing CF patients tend to modify not only their fatty acid patterns but also their protein patterns as a response to adaptation in the unfavourable environment of the CF lung.
authors.affiliation: Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Germany.
authors.forename: Pedrina Gonçalves
authors.initials: PG
authors.lastname: Vidigal
authors.affiliation: Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Mosel
authors.affiliation: Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Germany.
authors.forename: Hedda Luise
authors.initials: HL
authors.lastname: Koehling
authors.affiliation: Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Germany.
authors.forename: Karl Dieter
authors.initials: KD
authors.lastname: Mueller
authors.affiliation: Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Buer
authors.affiliation: Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Germany.
authors.forename: Peter Michael
authors.initials: PM
authors.lastname: Rath
authors.affiliation: Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Germany.
authors.forename: Joerg
authors.initials: J
authors.lastname: Steinmann
mesh_terms: D000293:Adolescent; D000328:Adult; D001426:Bacterial Proteins / Q000032:analysis*; D001431:Bacteriological Techniques / Q000379:methods*; D002648:Child; D002849:Chromatography, Gas / Q000379:methods*; D016000:Cluster Analysis; D003550:Cystic Fibrosis / Q000150:complications; D004783:Environmental Microbiology; D005227:Fatty Acids / Q000032:analysis*; D005260:Female; D016905:Gram-Negative Bacterial Infections / Q000175:diagnosis* / Q000382:microbiology; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D025341:Principal Component Analysis; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D020615:Stenotrophomonas maltophilia / Q000737:chemistry / Q000302:isolation & purification*; D013997:Time Factors; D055815:Young Adult
chemical_list: D001426:Bacterial Proteins; D005227:Fatty Acids