Outer membrane proteins: key players for bacterial adaptation in host niches.

Outer membrane proteins (OMPs) of Gram-negative bacteria have diverse functions and are directly involved in the interaction with various environments encountered by pathogenic organisms. Thus, OMPs represent important virulence factors and play essential roles in bacterial adaptation to host niches, which are usually hostile to invading pathogens. Understanding the structure and functions of bacterial OMPs will facilitate the design of antimicrobial drugs and vaccines. In this paper, we will present a brief review on OMPs that contribute to bacterial adaptive responses including iron uptake, antimicrobial peptide resistance, serum resistance, and drug/bile resistance.