Development of an in vitro colonization model to investigate Staphylococcus aureus interactions with airway epithelia

Cell Microbiol. 2016 May;18(5):720-32. doi: 10.1111/cmi.12543. Epub 2016 Jan 12.

Abstract

Staphylococcus aureus is a bacterial pathogen responsible for a wide range of diseases and is also a human commensal colonizing the upper respiratory tract. Strains belonging to the clonal complex group CC30 are associated with colonization, although the colonization state itself is not clearly defined. In this work, we developed a co-culture model with S. aureus colonizing the apical surface of polarized human airway epithelial cells. The S. aureus are grown at the air-liquid interface to allow an in-depth evaluation of a simulated colonization state. Exposure to wild-type, S. aureus bacteria or conditioned media killed airway epithelial cells within 1 day, while mutant S. aureus strains lacking alpha-toxin (hla) persisted on viable cells for at least 2 days. Recent S. aureus CC30 isolates are natural hla mutants, and we observed that these strains displayed reduced toxicity toward airway epithelial cells. Quantitative real-time polymerase chain reaction of known virulence factors showed the expression profile of S. aureus grown in co-culture correlates with results from previous human colonization studies. Microarray analysis indicated significant shifts in S. aureus physiology in the co-culture model toward lipid and amino acid metabolism. The development of the in vitro colonization model will enable further study of specific S. aureus interactions with the host epithelia.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Adhesion / genetics
  • Bacterial Toxins / genetics*
  • Bacterial Toxins / metabolism
  • Coculture Techniques
  • Epithelial Cells / microbiology*
  • Epithelial Cells / pathology
  • Hemolysin Proteins / genetics*
  • Hemolysin Proteins / metabolism
  • Humans
  • Mutation
  • Respiratory System / microbiology
  • Respiratory System / pathology
  • Staphylococcal Infections / genetics*
  • Staphylococcal Infections / microbiology
  • Staphylococcal Infections / pathology
  • Staphylococcus aureus / genetics*
  • Staphylococcus aureus / pathogenicity
  • Virulence / genetics

Substances

  • Bacterial Toxins
  • Hemolysin Proteins
  • staphylococcal alpha-toxin