S. maltophilia is catalase-positive, oxidase-negative (which distinguishes it from most other members of the genus) and has a positive reaction for extracellular DNase.

Adherence of this organism to abiotic surfaces such as medical implants and catheters represents a major risk for hospitalized patients.

S. maltophilia adheres strongly and forms biofilm on plastic surfaces although these abilities may vary greatly between strains.

S. maltophilia substantially influences the architecture of P. aeruginosa structures, causing development of extended filaments.

[8][9] The growth of S. maltophilia in microbiological cultures of respiratory or urinary specimens is difficult to interpret due to its low pathogenicity, and is not proof of infection.

These OMVs stimulate the expression of proinflammatory cytokine and chemokine genes, including interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor-α and monocyte chemoattractant protein-1.

[13] S. maltophilia is naturally resistant to many broad-spectrum antibiotics (including all carbapenems) due to the production of two inducible chromosomal metallo-β-lactamases (designated L1 and L2).

S. maltophilia is ubiquitously present in the environment and impossible to eradicate, which makes prevention also extremely difficult.

Risk factors associated with Stenotrophomonas infection include HIV infection, malignancy, cystic fibrosis, neutropenia, mechanical ventilation, extracorporeal membrane oxygenation, central venous catheters, recent surgery, trauma, prolonged hospitalization, intensive care unit admission and broad-spectrum antibiotic use.