title: Comparative proteomic analysis of Salmonella tolerance to the biocide active agent triclosan.
abstract: Concern has been expressed about the overuse of biocides in farm animal production and food industries. Biocide application can create selective pressures that lead to increased tolerance to one or more of these compounds and are concomitant with the emergence of cross-resistance to antibiotics. A triclosan sensitive Salmonella enterica serovar Typhimurium and the isogenic triclosan tolerant mutant were studied at the proteomic level in order to elucidate cellular mechanisms that facilitate biocide tolerance. 2-D differential fluorescent gel electrophoresis (DIGE) compared protein profiles of parent and mutant Salmonella, in the presence and absence of triclosan. Differentially expressed proteins were identified by mass spectrometry and divided into two groups: Group A describes proteins differentially expressed between susceptible and triclosan tolerant Salmonella and includes the known triclosan target FabI which contained a mutation at the triclosan target binding site. Group B identified proteins differentially expressed in response to triclosan exposure and defines a general cell defence network. Only four proteins were common to both groups highlighting the diverse range of pathways employed by Salmonella to counteract biocides. These data suggest that sub-lethal concentrations of triclosan induce discernible changes in the proteome of exposed Salmonella and provide insights into mechanisms of response and tolerance.
authors.affiliation: UCD Centre for Food Safety & the Centre for Food-borne Zoonomics, School of Public Health, Physiotherapy & Population Science, Ireland.
authors.forename: O
authors.initials: O
authors.lastname: Condell
authors.forename: Á
authors.initials: Á
authors.lastname: Sheridan
authors.forename: K A
authors.initials: KA
authors.lastname: Power
authors.forename: R
authors.initials: R
authors.lastname: Bonilla-Santiago
authors.forename: K
authors.initials: K
authors.lastname: Sergeant
authors.forename: J
authors.initials: J
authors.lastname: Renaut
authors.forename: C
authors.initials: C
authors.lastname: Burgess
authors.forename: S
authors.initials: S
authors.lastname: Fanning
authors.forename: J E
authors.initials: JE
authors.lastname: Nally
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D004202:Disinfectants / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial / Q000502:physiology*; D020543:Proteome / Q000378:metabolism*; D012486:Salmonella typhimurium / Q000187:drug effects* / Q000378:metabolism*; D013045:Species Specificity; D014260:Triclosan / Q000494:pharmacology*
chemical_list: D001426:Bacterial Proteins; D004202:Disinfectants; D020543:Proteome; D014260:Triclosan