Evaluating Metabolic Pathways and Biofilm Formation in Stenotrophomonas maltophilia
Cierra M Isom1, Blake Fort1, Gregory G Anderson1
1Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, USA.
Abstract:
Stenotrophomonas maltophilia has recently arisen as a prominent nosocomial pathogen because of its high antimicrobial resistance and ability to cause chronic respiratory infections. Often the infections are worsened by biofilm formation which enhances antibiotic tolerance. We have previously found that mutation of the gpmA gene, encoding the glycolytic enzyme phosphoglycerate mutase, impacts the formation of this biofilm on biotic and abiotic surfaces at early time points. This finding, indicating an association between carbon source and biofilm formation, led us to hypothesize that metabolism would influence S. maltophilia biofilm formation and planktonic growth. In the present study, we tested the impact of various growth substrates on biofilm levels and growth kinetics to determine metabolic requirements for these processes. We found that S. maltophilia wild type preferred amino acids versus glucose for planktonic and biofilm growth and that gpmA deletion inhibited growth in amino acids. Furthermore, supplementation of the ΔgpmA strain by glucose or ribose phenotypically complemented growth defects. These results suggest that S. maltophilia shuttles amino acid carbon through gluconeogenesis to an undefined metabolic pathway supporting planktonic and biofilm growth. Further evaluation of these metabolic pathways might reveal novel metabolic activities of this pathogen. IMPORTANCE Stenotrophomonas maltophilia is a prominent opportunistic pathogen that often forms biofilms during infection. However, the molecular mechanisms of virulence and biofilm formation are poorly understood. The glycolytic enzyme phosphoglycerate mutase appears to play a role in biofilm formation, and we used a mutant in its gene (gpmA) to probe the metabolic circuitry potentially involved in biofilm development. The results of our study indicate that S. maltophilia displays unique metabolic activities, which could be exploited for inhibiting growth and biofilm formation of this pathogen.
Insights
Stenotrophomonas maltophilia utilizes amino acids for growth and biofilm formation, with the gpmA gene impacting this process. Understanding its unique metabolism may offer new therapeutic targets.
Area of Science:
- Microbiology
- Molecular Biology
- Pathogenesis
Background:
- Stenotrophomonas maltophilia is a significant nosocomial pathogen.
- Biofilm formation enhances antibiotic tolerance in S. maltophilia infections.
- The glycolytic enzyme phosphoglycerate mutase (gpmA) influences early biofilm formation.
Purpose of the Study:
- To investigate the metabolic requirements for S. maltophilia biofilm formation and planktonic growth.
- To determine the role of carbon source utilization in S. maltophilia virulence.
- To identify potential metabolic targets for controlling S. maltophilia infections.
Main Methods:
- Comparative analysis of wild-type and gpmA deletion mutant strains of S. maltophilia.
- Growth kinetics assays with various carbon sources (amino acids, glucose, ribose).
- Biofilm formation assays on biotic and abiotic surfaces.
Main Results:
- S. maltophilia preferentially utilizes amino acids over glucose for both planktonic and biofilm growth.
- Deletion of gpmA significantly inhibits growth on amino acids.
- Supplementation with glucose or ribose complements the growth defects in the gpmA deletion strain.
Conclusions:
- S. maltophilia metabolism involves shuttling amino acid carbon through gluconeogenesis for growth and biofilm development.
- The gpmA gene and associated metabolic pathways are critical for S. maltophilia virulence.
- Targeting these unique metabolic activities could lead to novel strategies against S. maltophilia infections.
