Stenotophomonas Maltophilia As Not Just a Mere Colonozer: Two Cases of Urinary Tract Infection and Multidrug-Resistant Respiratory Infection

Stenotrophomonas maltophilia, though commonly reported as an opportunistic respiratory pathogen, has been known to cause a wide variety of illnesses, including urinary tract infection, biliary sepsis, bacteremia, and osteomyelitis. Malignancy and immunocompromised states are the biggest risk factors associated with Stenotrophomonas maltophilia infection. Being an emerging nosocomial infection globally, the bacteria should no longer be considered as just a mere colonizer, and emphasis should be laid on understanding the mechanisms of resistance, modes of prevention, and treatment. We present the case of an 89-year-old Haitian American male with a past medical history of prostate adenocarcinoma and urinary retention following transurethral resection of the prostate, requiring an indwelling urinary catheter who presented to the emergency department with poorly draining Foley, hematuria, and urinary retention associated with suprapubic pain. Laboratory investigations revealed elevated creatinine, and urine analysis was suggestive of infection. The patient was admitted for the treatment of complicated urinary tract infection and acute kidney injury in the setting of urinary retention. Urine culture and sensitivity results revealed Stenotrophomonas maltophilia sensitive to trimethoprim/sulfamethoxazole, to which the patient responded well. During the course of the patient's hospital stay, his kidney function gradually improved. We also present the case of a 68-year-old female with a past medical history of chronic tracheostomy dependence who presented to the emergency department for worsening fatigue and copious secretions from tracheostomy. Chest X-ray was suggestive of consolidation/edema, and the patient got admitted under the impression of septic encephalopathy due to pneumonia in a patient with tracheostomy. The patient received appropriate antibiotic therapy, and her mental status improved. However, the patient late developed respiratory distress, tachycardia, and tachypnea with worsening right-sided infiltrates on chest X-ray. The patient was started on vancomycin and cefepime for possible aspiration pneumonia. Cefepime was later changed to meropenem. Sputum culture and sensitivity results grew Stenotrophomonas maltophilia sensitive to meropenem which was continued. The patient's clinical status, laboratory and imaging findings improved over the course of her hospital stay.