SESSION TYPE: Infectious Disease Student/Resident Case Report Posters II
PRESENTED ON: Tuesday, October 23, 2012 at 01:30 PM - 02:30 PM
INTRODUCTION: Stenotrophomonas maltophilia (S.maltophilia) is a rising cause of nosocomial pneumonia with a mortality of 20-30%. Avid use of broad-spectrum antibiotics is an important risk factor for developing the infection. Other associations include the use of mechanical ventilation and therapeutic respiratory apparatus. Quinolones and trimethoprim/sufamethoxazole (TMP/SMX) are the treatment options, however, with rising resistance to these drugs, we are limited with treatment modalities.
CASE PRESENTATION: A 78-year-old male was managed in the intensive care unit (ICU) for paralytic ileus complicated with hypotension. For comfort, oxygen and nebulized treatments were regimented. On day three, patient was febrile with chest x-ray notable for focal infiltrates. Broad spectrum antibiotic coverage with vancomycin and pipercillin-tazobactam were begun. Repeated blood cultures were negative. Sputum cultures grew S. maltophilia susceptible to levofloxacin and TMP-SMX. Antibiotic coverage was narrowed to intravenous moxifloxacin. TMP-SMX was deferred; orally due to continued ileus and intravenous due to unavailability. White blood counts, chest congestion, and sputum production continued to increase. On day 14, patient was intubated and mechanically ventilated for progressive respiratory distress. Chest radiography showed multifocal pneumonia. Respiratory cultures again grew S. maltophilia, this time resistant to levofloxacin but susceptible to TMP-SMX and ceftazidime. Treatment with inhaled colistin and ceftazidime was started. The patient continued to need increased respiratory support and, on day 21, family wished for comfort care with elective extubation, ensuing his demise.
DISCUSSION: This case highlights the ill-fate of S. maltophilia pneumonia, but, despite its high mortality, little is known about the bacterium. A common practice, today, is commencing broad-spectrum antibiotics for most hospitalized patients; the resultant iatrogenic immunosuppression imposes an increase of the pneumonia. S. maltophilia exhibits multidrug resistance through its multidrug efflux pumps and production of very broad-spectrum metallo-β-lactamases. Hence, traditional gram negative coverage affords negative impact. Quinolones and TMP-SMX are drugs of choice; but its use is hampered by resistance and drug limitations. Drugs observed to have good in-vitro activity against the bacterium have limited clinical data. Management of this infection portends a rising problem, with no existent guidelines.
CONCLUSIONS: In conclusion, the suspicion for S. maltophilia infection should be high in cases afflicted with hospital acquired pneumonia. Rigorous studies are needed to define a wider array of treatment options and methods to minimize hospital transmission of S. maltophilia.
1) Wood GC et al.Treatment of recurrent Stenotrophomonas maltophilia ventilator-associated pneumonia with doxycycline and aerosolized colistin. Annals of Pharmacotherapy 2010; 44:1665-68
DISCLOSURE: The following authors have nothing to disclose: Ishna Poojary
No Product/Research Disclosure InformationUniversity of Arizona, Tucson, AZ