Trimethoprim-Sulfamethoxazole for Treatment of Stenotrophomonas maltophilia Pneumonia in a Neonate.

Neonates are susceptible to numerous infections. Factors that predispose these patients to nosocomial infections include very low birth weight, small size for gestational age, immunologic immaturity, and exposure to invasive procedures, including insertion of intravascular catheters and assisted ventilation. Stenotrophomonas maltophilia is an opportunistic, gram-negative aerobic bacillus with a high level of intrinsic resistance that is known to cause nosocomial infections. This organism may cause infections of many different systems, including bloodstream infections, urinary tract infections, meningitis, and (most commonly) pneumonia. Since neonatal patients are immunocompromised, infections with S. maltophilia are considered life-threatening in this population. There is very little evidence in the literature indicating the appropriate doses of trimethoprim–sulfamethoxazole required to treat S. maltophilia infections in neonates. This article describes a case in which trimethoprim–sulfamethoxazole was used to treat such an infection, with escalating doses used and tolerated.