Jennifer Rao

Tracking pathogens in our water networks

Stenotrophomonas maltophilia

Stenotrophomonas maltophilia is a gram-negative bacterium that is multi drug resistant (MDR). It is also an environmental organism that is typically associated with wet surfaces or aqueous solutions. Some of the environments where S. maltophilia has been found include catheters, endoscopes, nebulizers, hand-washing soaps, sink drains, faucets, tap water, and contact lens solution.

A significant attribute of S. maltophilia is its ability to form biofilms, especially on plastic surfaces. These include surfaces of medical equipment such as waterlines, catheters, nebulizers, and ventilators, as well as inside potable water distribution systems.  Additionally, S. maltophilia cells can survive with minimal nutrients by forming ultramicrocells (UMC). These UMC are between 0.1-0.2 um and can pass through most filtration units. S. maltophilia UMC have been recovered from polyvinyl chloride pipe walls within chlorinated drinking water systems. (Brooke 2012)

S. maltophilia has been identified as one of the 11 most frequently recovered organisms from patient infections in intensive care units across the United States (Lockhart, et al. 2007). In other studies S. maltophilia was the 3rd most frequently isolated bacteria from patients with bacteremia (an infection of the blood) (Osawa, et al. 2018). S. maltophilia is resistant to multiple antibiotics and is associated with considerable morbidity in cancer patients and immunosuppressed people. It is most commonly associated with respiratory infections but has also been linked to acute exacerbations of other conditions such as chronic obstructive pulmonary disease, bacteremia, endocarditis, and meningitis. Treatment of infection is hampered by the intrinsic resistance of S. maltophilia to many classes of antibiotics. (Looney, Narita and Muhlemann 2009).

References

  1. Brooke, Joanna S. 2012. “Stenotrophomonas maltophilia: an Emerging Global Opportunistic Pathogen.” Clinical Microbiology Reviews 2-41.
  2. Lockhart, S. R., M. A. Abramson, S. E. Beekmann, G. Gallagher, S. Riedel, D. J. Diekema, J. P. Quinn, and G. V Doern. 2007. “Antimicrobial resistance among gram-negative bacili causing infections in intensive care unit patients in the United States Between 1993 and 2004.” Clinical Microbiology 3352-9.
  3. Looney, John W., Masahi Narita, and Kathrin Muhlemann. 2009. “Stenotrophomonas maltophilia: An emerging opportunist human pathogen.” The Lancet Infectious Diseases 312-323.
  4. Osawa, Kayo, Katsumi Shigemura, Koichi Kitagawa, Issei Tokimatsu, and Masato Fujisawa. 2018. “Risk factors for death from Stenotrophomonas maltophilia bacteremia.” Journal of Infection and Chemotherapy 632-636.