Chaperone-dependent mechanisms for acid resistance in enteric bacteria

Trends Microbiol. 2012 Jul;20(7):328-35. doi: 10.1016/j.tim.2012.03.001. Epub 2012 Mar 27.


The extremely acidic environment of the mammalian stomach not only serves to facilitate food digestion but also acts as a natural barrier against infections of food-borne pathogens. Many pathogenic bacteria, such as enterohemorrhagic Escherichia coli, can breach this host defense and cause severe diseases. These pathogens have evolved multiple intricate strategies to overcome the bactericidal activity of acids. In particular, recent studies have uncovered the central roles of two periplasmic chaperones, HdeA and HdeB, in protecting enteric bacteria from extremely acidic conditions. Here, we review recent advances in the understanding of the acid resistance mechanisms of Gram-negative bacteria and focus on the mechanisms of HdeA and HdeB in preventing acid-induced protein aggregation and facilitating protein refolding following pH neutralization.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Acids / toxicity*
  • Escherichia coli / drug effects*
  • Escherichia coli / metabolism*
  • Escherichia coli Proteins / metabolism*
  • Humans
  • Molecular Chaperones / metabolism*
  • Stress, Physiological


  • Acids
  • Escherichia coli Proteins
  • Molecular Chaperones
  • hdeA protein, E coli
  • hdeB protein, E coli