title: Proteomic response of β-lactamases-producing Enterobacter cloacae complex strain to cefotaxime-induced stress.
abstract: Bacteria of the Enterobacter cloacae complex are among the ten most common pathogens causing nosocomial infections in the USA. Consequently, increased resistance to β-lactam antibiotics, particularly expanded-spectrum cephalosporins like cefotaxime (CTX), poses a serious threat. Differential In-Gel Electrophoresis (DIGE), followed by LC-MS/MS analysis and bioinformatics tools, was employed to investigate the survival mechanisms of a multidrug-resistant E. hormaechei subsp. steigerwaltii 51 carrying several β-lactamase-encoding genes, including the 'pandemic' blaCTX-M-15 After exposing the strain with sub-minimal inhibitory concentration (MIC) of CTX, a total of 1072 spots from the whole-cell proteome were detected, out of which 35 were differentially expressed (P ≤ 0.05, fold change ≥1.5). Almost 50% of these proteins were involved in cell metabolism and energy production, and then cell wall organization/virulence, stress response and transport. This is the first study investigating the whole-cell proteomic response related to the survival of β-lactamases-producing strain, belonging to the E. cloacae complex when exposed to β-lactam antibiotic. Our data support the theory of a multifactorial synergistic effect of diverse proteomic changes occurring in bacterial cells during antibiotic exposure, depicting the complexity of β-lactam resistance and giving us an insight in the key pathways mediating the antibiotic resistance in this emerging opportunistic pathogen.
authors.affiliation: Department of Biology, Faculty of Science, University of Split, Teslina 12, 21000 Split, Croatia amaravic@pmfst.hr.
authors.forename: Ana
authors.initials: A
authors.lastname: Maravić
authors.affiliation: Department of Molecular Biology, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia Mediterranean Institute for Life Sciences, Meštovićevo šetalište 45, 21000 Split, Croatia.
authors.forename: Svjetlana
authors.initials: S
authors.lastname: Cvjetan
authors.affiliation: Mediterranean Institute for Life Sciences, Meštovićevo šetalište 45, 21000 Split, Croatia.
authors.forename: Marina
authors.initials: M
authors.lastname: Konta
authors.affiliation: Mediterranean Institute for Life Sciences, Meštovićevo šetalište 45, 21000 Split, Croatia.
authors.forename: Romain
authors.initials: R
authors.lastname: Ladouce
authors.affiliation: Mediterranean Institute for Life Sciences, Meštovićevo šetalište 45, 21000 Split, Croatia.
authors.forename: Fernando A
authors.initials: FA
authors.lastname: Martín
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002439:Cefotaxime / Q000494:pharmacology*; D002473:Cell Wall / Q000378:metabolism; D019295:Computational Biology / Q000379:methods; D004734:Energy Metabolism; D016972:Enterobacter cloacae / Q000145:classification / Q000187:drug effects* / Q000378:metabolism*; D005407:Flagella / Q000378:metabolism; D020543:Proteome; D040901:Proteomics / Q000379:methods; D013312:Stress, Physiological / Q000187:drug effects*; D014774:Virulence; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000096:biosynthesis*
chemical_list: D000900:Anti-Bacterial Agents; D020543:Proteome; D001618:beta-Lactamases; D002439:Cefotaxime
keywords: 2D-DIGE; CTX-M-15; Enterobacter cloacae complex; Enterobacter hormaechei; Proteomics; β-lactamase