AAC Accepts, published online ahead of print on 28 August 2006

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Mangalappalli-Illathu, A. K. Articles by Korber, D. R. Search for Related Content PubMed PubMed Citation Articles by Mangalappalli-Illathu, A. K. Articles by Korber, D. R.

 Previous Article  |  Next Article 

Antimicrob. Agents Chemother. doi:10.1128/AAC.00573-06
Copyright (c) 2006, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.

Adaptive Resistance and Differential Protein Expression of Salmonella enterica Serovar Enteritidis Biofilms Exposed to Benzalkonium Chloride

Anil K. Mangalappalli-Illathu and Darren R. Korber^*

Department of Applied Microbiology and Food Science, University of Saskatchewan, Saskatoon, Saskatchewan, Canada

^* To whom correspondence should be addressed. Email: korber{at}sask.usask.ca.

Development of adaptive resistance of Salmonella enterica serovar Enteritidis ATCC 4931 biofilms following either continuous (1 µg ml^-1) or intermittent (10 µg ml^-1 for 10 min daily) exposure to benzalkonium chloride (BC) was examined. Biofilms adapted to BC over a 144 h period could survive a normally-lethal BC challenge (500 µg ml^-1 for 10 min) and then re-grow, as determined by increases in biofilm thickness, total biomass, and ratio of viable to non-viable biomass. Exposure of untreated control biofilms to the lethal BC challenge resulted in biofilm erosion and cell death. Proteins found to be up-regulated following BC adaptation were those involved in energy metabolism (TpiA and Eno), amino acid and protein biosynthesis (WrbA, TrxA, RplL, Tsf, Tuf, DsbA, and RpoZ), nutrient-binding (FruB), adaptation (CspA), detoxification (Tpx, SodB, and a probable peroxidase), and degradation of 1,2-propanediol (PduJ and PduA). A putative universal stress protein (YnaF) was also found to be up-regulated. Proteins involved in proteolysis (DegQ), cell envelope formation (RfbH), adaptation (UspA), heat shock response (DnaK), and broad regulatory functions (Hns) were found to be down-regulated following adaptation. An overall increase in cellular protein biosynthesis was deduced from the significant up-regulation of ribosomal subunit proteins, translation elongation factors, and amino acid biosynthesis protein and down-regulation of serine endoprotease. Cold-shock response, stress response, and detoxification are suggested to play roles in the adaptive resistance of S. serovar Enteritidis biofilms to BC.

This article has been cited by other articles:

• Mangalappalli-Illathu, A. K., Vidovic, S., Korber, D. R. (2008). Differential Adaptive Response and Survival of Salmonella enterica Serovar Enteritidis Planktonic and Biofilm Cells Exposed to Benzalkonium Chloride. Antimicrob. Agents Chemother. 52: 3669-3680 [Abstract] [Full Text]  
• Karatzas, K. A. G., Randall, L. P., Webber, M., Piddock, L. J. V., Humphrey, T. J., Woodward, M. J., Coldham, N. G. (2008). Phenotypic and Proteomic Characterization of Multiply Antibiotic-Resistant Variants of Salmonella enterica Serovar Typhimurium Selected Following Exposure to Disinfectants. Appl. Environ. Microbiol. 74: 1508-1516 [Abstract] [Full Text]