title: Proteomic profiling of Cronobacter turicensis 3032, a food-borne opportunistic pathogen.
abstract: Members of the genus Cronobacter are opportunistic pathogens for neonates and are often associated with contaminated milk powder formulas. At present little is known about the virulence mechanisms or the natural reservoir of these organisms. The proteome of Cronobacter turicensis 3032, which has recently caused two deaths, was mapped aiming at a better understanding of physiology and putative pathogenic traits of this clinical isolate. Our analyses of extracellular, surface-associated and whole-cell proteins by two complementary proteomics approaches, 1D-SDS-PAGE combined with LC-ESI-MS/MS and 2D-LC-MALDI-TOF/TOF MS, lead to the identification of 832 proteins corresponding to a remarkable 19% of the theoretically expressed protein complement of C. turicensis. The majority of the identified proteins are involved in central metabolic pathways, translation, protein folding and stability. Several putative virulence factors, whose expressions were confirmed by phenotypic assays, could be identified: a macrophage infectivity potentiator involved in C. turicensis persistence in host cells, a superoxide dismutase protecting the pathogen against reactive oxygen species and an enterobactin-receptor protein for the uptake of siderophore-bound iron. Most interestingly, a chitinase and a metalloprotease that might act against insects and fungi but no casein hydrolysing enzymes were found, suggesting that there is an environmental natural habitat of C. turicensis 3032.
authors.affiliation: Department of Microbiology, Institute of Plant Biology, UZH, Zurich, Switzerland.
authors.forename: Paula
authors.initials: P
authors.lastname: Carranza
authors.forename: Isabel
authors.initials: I
authors.lastname: Hartmann
authors.forename: Angelika
authors.initials: A
authors.lastname: Lehner
authors.forename: Roger
authors.initials: R
authors.lastname: Stephan
authors.forename: Peter
authors.initials: P
authors.lastname: Gehrig
authors.forename: Jonas
authors.initials: J
authors.lastname: Grossmann
authors.forename: Simon
authors.initials: S
authors.lastname: Barkow-Oesterreicher
authors.forename: Bernd
authors.initials: B
authors.lastname: Roschitzki
authors.forename: Leo
authors.initials: L
authors.lastname: Eberl
authors.forename: Kathrin
authors.initials: K
authors.lastname: Riedel
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D002633:Chemotaxis; D004755:Enterobacteriaceae / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism* / Q000472:pathogenicity; D005517:Foodborne Diseases / Q000382:microbiology*; D017510:Protein Folding; D021381:Protein Transport; D040901:Proteomics; D013312:Stress, Physiological; D037521:Virulence Factors / Q000737:chemistry / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D037521:Virulence Factors