Modeling reciprocal adaptation of Staphylococcus aureus and Pseudomonas aeruginosa co-isolates in artificial sputum...

Area of Science:

• Microbiology
• Infectious Diseases
• Biofilm Research

Background:

• Co-infections by Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) are common in cystic fibrosis (CF) airways.
• These co-infections exhibit greater antibiotic tolerance than single infections.
• Existing in vitro models lack clinical relevance, fail to mimic the CF airway environment, and do not represent biofilm growth.

Purpose of the Study:

• To develop and validate a novel dual-species biofilm model for studying S. aureus and P. aeruginosa co-infections.
• To investigate interspecies interactions and cross-adaptation using clinical isolates in a simulated CF environment.
• To assess the utility of the model for exploring bacterial behavior in CF lung infections.

Main Methods:

• Established a dual-species biofilm model using artificial sputum medium.
• Inoculated S. aureus prior to P. aeruginosa to ensure stable co-cultures.
• Applied the model to ten pairs of clinical isolates with diverse phenotypes.

Main Results:

• The model successfully maintained stable co-cultures of S. aureus and P. aeruginosa from clinical isolates.
• Co-isolates from individual patients demonstrated robust co-growth, supporting in vivo cross-adaptation.
• Cross-adaptation in the VBB496 pair involved reduced antagonism, decreased P. aeruginosa metabolite production, and increased S. aureus tolerance to these metabolites.

Conclusions:

• The developed dual-species biofilm model is a valuable tool for studying S. aureus and P. aeruginosa interactions in CF airways.
• The model facilitates research into bacterial cross-adaptation and its impact on antibiotic tolerance.
• Findings highlight the importance of considering interspecies dynamics in the context of CF lung infections.