Mycobacterium abscessus Cells Have Altered Antibiotic Tolerance and Surface Glycolipids in Artificial Cystic Fibrosis Sputum Medium

Antimicrob Agents Chemother. 2019 Jun 24;63(7):e02488-18. doi: 10.1128/AAC.02488-18. Print 2019 Jul.

Abstract

Mycobacterium abscessus is a biofilm-forming, multidrug-resistant nontuberculous mycobacterial (NTM) pathogen increasingly found in cystic fibrosis patients. Antibiotic treatment for these infections is often unsuccessful, partly due to M. abscessus's high intrinsic antibiotic resistance. It is not clear whether antibiotic tolerance caused by biofilm formation also contributes to poor treatment outcomes. We studied the surface glycolipids and antibiotic tolerance of M. abscessus biofilms grown in artificial cystic fibrosis sputum (ACFS) medium to determine how they are affected by nutrient conditions that mimic infection. We found that M. abscessus displays more of the virulence lipid trehalose dimycolate when grown in ACFS than when grown in standard lab medium. In ACFS medium, biofilm-associated cells were more antibiotic tolerant than planktonic cells in the same well. This contrasts with standard lab media, where both biofilm and planktonic cells are highly antibiotic tolerant. These results indicate that M. abscessus cell physiology in biofilms depends on environmental factors and that nutrient conditions found within cystic fibrosis infections could contribute to both increased virulence and antibiotic tolerance.

Keywords: Mycobacterium; Mycobacterium abscessus; antibiotic resistance; antibiotic tolerance; artificial cystic fibrosis sputum; biofilms; cystic fibrosis; glycolipids; multidrug resistance; nontuberculous mycobacterium.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / pharmacology*
  • Biofilms / drug effects
  • Cystic Fibrosis / microbiology
  • Drug Tolerance
  • Glycolipids / metabolism*
  • Mycobacterium Infections, Nontuberculous / drug therapy
  • Mycobacterium Infections, Nontuberculous / microbiology
  • Mycobacterium abscessus / drug effects*
  • Sputum / microbiology*

Substances

  • Anti-Bacterial Agents
  • Glycolipids