engleski

Proteome changes of food borne pathogens treated with disinfectants based on pyridoxal oxime derivatives

Antimicrobial agents based on quaternary ammonium salts (QAC) have been extensively used as disinfectants in food-processing industries and medicine. It is suggested that these substances exhibit antimicrobial properties by adsorption to the outer cellular wall and by further penetration into bacterial cells. This results in inhibition of microbial growth and finally in cell death. It was also observed that QAC are decidedly more active against Gram-positive bacteria. Recently, series of different pyridoxal oximes were synthesized in a form of bromide and chloride quaternary salts and their antimicrobial activity was tested against Bacillus subtilis and Escherichia coli, which were used as model organisms for Gram- positive and Gram-negative bacteria that cause food contamination. In this work, quantitative gel-free proteomic investigations by LC-ESI MS/MS were used to identify changes in proteomes of these two bacteria after growth under the inhibition with four different disinfectants based on pyridinium oxime derivatives. Up- and down- regulated proteins were identified and their cellular localizations and functions were determined by gene ontology searching. Proteome changes presented here demonstrate different mechanism of action of these disinfectants. In Gram- positive food pathogen B. subtilis, the inhibitory substances seem to act mainly at the cell surface and cause the most changes in the integral membrane components, while in the Gram-negative pathogen E. coli, intracellular proteins were more affected. This research contributes to the investigations of the virulence and pathogenicity of food borne bacteria and their survival under stress conditions, and can also lead the way for further development of new inhibitors of microbial growth and studies of mechanism of their actions.

quantitative proteomics ; food borne pathogens ; disinfectants ; mechanism of action

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