The Mla Pathway Plays an Essential Role in the Intrinsic Resistance of Burkholderia cepacia Complex Species to Antimicrobials and Host Innate Components

Abstract

The outer membrane of Gram-negative bacteria acts as an effective barrier against toxic compounds, and therefore compromising this structure could increase sensitivity to currently available antibiotics. In this study, we show that the Mla pathway, a system involved in maintaining the integrity of the outer membrane, is genetically and functionally different in Burkholderia cepacia complex species compared to that in other proteobacteria. Mutants in mla genes of Burkholderia cenocepacia or Burkholderia dolosa were sensitive to Gram-positive antibiotics, while this effect was not observed in Escherichia coli or Pseudomonas aeruginosa . The Mla pathway in Burkholderia species may represent an ideal genus-specific target to address their intrinsic antimicrobial resistances.