Clinical ineffectiveness of latamoxef for Stenotrophomonas maltophilia infection

Objectives: Stenotrophomonas maltophilia shows wide-spectrum resistance to antimicrobials and causes various infections in immunocompromised or critically ill patients with high mortality. In this era of antibiotics resistance, a revival of old antibiotics is now featured. We examined the clinical usefulness of latamoxef (LMOX) for the treatment of S. maltophilia infection. Patients and methods: The observational study was retrospectively performed at Okayama University Hospital (Okayama, Japan) from January 2011 to December 2013. LMOX was administered to 12 patients with S. maltophilia infection, with eleven of those patients being admitted to the intensive care unit. Results: Underlying conditions of the patients included postoperation, hematological transplantation, hepatic transplantation, and burn. Major infectious foci were surgical site infection (six cases), respiratory infection (four cases), blood stream infection (three cases), and burn site infection (one case). The doses of LMOX administered ranged from 1 g/d to 3g d for ten adult patients and from 40 mg/kg/ d to 80 mg/kg/d for two pediatric patients. Microbiologic failure was seen in five (41.7%) of 12 cases, and 30-day and hospital mortality rates were 25% and 50%, respectively. Minimum inhibitory concentrations of LMOX were higher in the deceased group (4-64 mu g/mL) than in the surviving group (1-4 mu g/ mL). Conclusion: LMOX treatment is not recommended for the treatment of S. maltophilia infection. Further investigation would be needed before its clinical use.