Antibiotic penetration in liver infection: a case of tobramycin failure responsive to moxalactam

A 23-year-old man sustained a severe liver laceration which subsequently became infected with Enterobacter aerogenes. Blood cultures were positive for this organism and the patient experienced sepsis. Over the course of 18 days, his bilirubin and serum creatinine increased from normal to 40 and 2.7 mg/dl, respectively. Tobramycin, clindamycin, and penicillin failed to control the infection despite in vitro sensitivity of the organism to tobramycin. Moxalactam was started as a last resort, and the symptoms of infection resolved in 12 h. Both hepatic and renal function returned to normal, and the patient was discharged without complications. Moxalactam concentrations in wound fluid exceeded serum concentrations and the usual minimum inhibitory concentration of the infecting organism. A likely explanation for response to moxalactam, in face of tobramycin failure, was that moxalactam was able to reach the site of infection.