IF: 0.957
Cite Score:

Effects of Salt Stress on the Antimicrobial Drug Resistance and Protein Pattern of Staphylococcus aureus


Haleh Ganjian 1 , Iraj Nikokar 2 , * , Azita Tieshayar 1 , Ali Mostafaei 3 , Nour Amirmozafari 4 , Sara Kiani 5


1 Azad University of Lahijan, IR Iran

2 Laboratory of Microbiology and Immunology of Infectious Diseases, Paramedicine Faculty, Guilan University of Medical Sciences, Nikokariraj@yahoo.com, IR Iran

3 Kermanshah University of Medical Sciences, IR Iran

4 Tehran University of Medical Sciences, IR Iran

5 Kermanshah University of Medical Sciences, Kermanshah


Jundishapur Journal of Microbiology: 5 (1); 328-331
Article Type: Research Article
Received: March 1, 2011
Accepted: May 1, 2011




Background: Staphylococcus aureus is the causative agent of a high percentage of nosocomially acquired infections and food-borne illnesses. Antimicrobial resistance of S. aureus, especially methicillin-resistant S. aureus (MRSA), continues to be a concernfor clinicians worldwide.
Objectives: The aim of this study was to investigate the effects of salt stress on the antimicrobial drug resistance and protein profile of S. aureus.
Materials and Methods: Staphylococcus aureus (ATCC 25823) was grown in trypticase soy broth at 37°C. Cells in the exponential growth phase were gradually exposed to sub-lethal salt stress with concentrations ranging from 5% to35% (wt/vol). There after, these cells were harvested and re-suspended in a tube containing 0.5mL of saline. To standardize the number of bacteria, the bacterial suspension was compared to the 0.5 McFarland standard suspension.Antibiotic susceptibility was determined using the disk diffusion method, and the method involved plating of cell suspensions with stressed cells and unstressed cells on Mueller-Hinton agar plates. The pooled proteins from each condition were analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE).
Results: Compared to the unstressed cells, the cells exposed to salt showed significant changes in resistance to rifampicin (P=0.032), penicillin (P=0.02) and methicillin (P=0.001). Furthermore, SDS-PAGE analysis of pooled proteins from cells exposed to salt showed changes in the protein profile.
Conclusions: We conclude that salt stress is responsible for the changes in protein profileand antimicrobial resistance of S. aureus, especially to methicillin

  • Implication for health policy/practice/research/medical education:
    The results of this study indicate that the use of high amount of salt in food preservation can lead to the development of antibioticresistantpopulation of S. aureus as a food-borne pathogen.
  • Please cite this paper as:
    Ganjian H, Nikokar I, Tieshayar A, Mostafaei A, Amirmozafari N, Kiani S. Effects of Salt Stress on the Antimicrobial Drug Resistance and Protein Profile of Staphylococcus aureus. Jundishapur J Microbiol. 2012; 5(1):328-31.
  •  DOI: 10.5812/kowsar.20083645.2375

© 2012, AJUMS. Published by Kowsar M.P.Co. All rights reserved.


Staphylococcus aureus Salt Stress Antibiotic Resistance Electrophoresis Polyacrylamide Gel

© 0, Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited.
Full Text

Full text is available in PDF